Characteristics of Orthodontic Treatment in Cancer Survivors: A Systematic Review

Background: Survival rates of cancer patients have increased globally and across age groups. Challenges arising from craniofacial growth-development disturbances and dental abnormalities might warrant modifications to standard orthodontic pathways of care. Objective: The aim of this study was to systematically summarize and critically assess the available literature regarding the characteristics of orthodontic treatment in cancer survivors. Materials and Methods: A systematic search was conducted in seven databases for studies on malignant tumor survivors having undergone orthodontic intervention with fixed appliances following cancer treatment up to August 2023. The outcomes of interest included quantitative data regarding various characteristics of orthodontic treatment and the post-treatment period. The risk of bias was assessed individually with the Newcastle-Ottawa scale. Results: Out of 347 records, 4 cohort studies were eventually included in the qualitative synthesis. Leukemia was the most common malignancy type, with treatment involving mainly chemotherapy and/or radiotherapy. The duration of orthodontic treatment in cancer survivors varied. Occlusal results, quality of life, and satisfaction were comparable to healthy peers. However, in some survivors’ groups, treatment was shorter and the final results were compromised. Root resorption and oral mucositis were reported among the treated cancer survivors. Reduced occlusal outcome stability during the retention period was also reported. Conclusions: Overall, the duration of orthodontic treatment varied among cancer survivors. The occlusal results achieved were similar to those of their healthy peers, though potentially less stable. Patient-reported outcomes did not differ significantly between cancer survivors and healthy individuals treated orthodontically.


Introduction
Cancer in young populations is rare but still constitutes a major health problem [1,2].Over the last 30 years, the international burden of cancer in children of up to 14 years of age has been declining, while opposite trends have been observed in adolescents and young adults aged up to 39 years [3,4].Fortunately, death rates have decreased globally and across age groups [3,4].In Europe, it has been estimated that almost eighty percent of affected young individuals survive at least five years, with the survival duration in certain cases being even longer [5,6] and continuously improving thanks to new treatment and support regimens [7].In 2020, the European childhood, adolescent, and young adult cancer There was no limitation regarding language or year of publication.An additional search was performed in the reference lists of the eligible articles (NK and MAM).After the removal of the duplicates using EndNote's duplicate identification strategy (EndNote X9, Clarivate, Philadelphia, PA, USA), they were then removed manually by EGK, NK, and MAM, who screened the retrieved studies and applied the inclusion criteria independently.In case of disagreement, another author (EGK) made an evaluation so as to settle on a consensus.

Study Selection, Data Collection, and Data Items
The located records were checked independently by NK and MAM.In any case of an unclear abstract, the full text was assessed.The following information was extracted from the finally eligible studies in predetermined forms: bibliographic details of the study; details on study design and verification of study eligibility; cancer survivors' characteristics where available (number, age, gender, type of cancer, cancer treatment, the time elapsed since treatment); characteristics of treatment and the post-treatment period, to include orthodontic diagnosis, time elapsed since cancer treatment, treatment mechanics, possible extractions carried out, the use of additional interventions (e.g., hyrax), treatment duration, treatment success/compromised treatments/early conclusion, data on occlusal outcomes/indices, unwanted sequelae, and complications, relapse, quality of life, satisfaction, etc.If clarifications were needed regarding the published data, or additional material was required, then attempts to contact the corresponding authors through emails were made.

Risk of Bias Assessment
The risk of bias was assessed by NK and MAM using the Newcastle-Ottawa Scale in all the above-mentioned processes.Disagreements were settled by discussion with EGK; following the relevant suggestions, kappa statistics were not calculated [32].

Data Synthesis, Risk of Bias across Studies, and Additional Analyses
Data synthesis, risk of bias across studies analyses, and additional analyses for "smallstudy effects" and publication bias were not performed finally due to the lack of an adequate number of studies and the variability of the available information [31].

Study Selection
Following the previously described search procedures, a total of 347 records were identified.After the removal of 97 duplicate records, we excluded a further 242 on the basis of their title and/or abstracts.Subsequently, eight papers were investigated for eligibility and four further records were excluded (Table 3).

Benign tumor
Li H, Hu J, Luo E, Zhu S, Li J. Treatment of osteochondroma in the mandibular condyle and secondary dentofacial deformities using surgery combined with orthodontics in adults.J Oral Maxillofac Surg.2014 Nov;72 (11):2295-317.
Following the previously described search procedures, a total of 347 records were identified.After the removal of 97 duplicate records, we excluded a further 242 on the basis of their title and/or abstracts.Subsequently, eight papers were investigated for eligibility and four further records were excluded (Table 3).

Cancer Survivors and Orthodontic Treatment Characteristics
The characteristics of the included studies are presented in Table 4.
One case-series study [33] and three cohort studies were located [34][35][36].Leukemia was the most common malignancy type among cancer survivors, with treatment involving mainly chemotherapy (usually with cyclophosphamide or methotrexate) and/or radiotherapy.Orthodontic treatment involved a variety of skeletal classes and orthodontic problems, and used fixed appliances, while some cases involved extractions or adjuncts such as hyrax.The reported periods of time elapsed between cancer treatment and orthodontic intervention included median or mean values of 8-9 years.
Most treated groups of cancer survivors concluded treatment in approximately a year, while Mitus-Kenig et al. [35] included a cancer survivor-treated group with a mean treatment duration of 19.3 months, and Mitus-Kenig et al. [36] reported on patients treated for mean of 17.6 months.In some patients, the treatment had to be concluded early due to the relapse of the malignancy [33].Compromised results were reported in the included studies [33,35]; however, the final weighted-PAR Index and the reduction in the weighted-PAR Index were not observed to differ between a cancer survivor group and a control group CG matched for age, gender, and malocclusion [35].The same was noted by Mitus-Kenig et al. [36] for the final weighted PAR and ICON indices when compared between treated cancer survivors and a matched group of healthy patients [36].Oral mucosa inflammation [33][34][35] and root resorption [34,35] were reported among the treated cancer survivors.No root resorption was encountered in a cancer survivor group completing treatment within 12 months [35].
Cancer survivors demonstrated significantly more post-orthodontic treatment changes following a period of three years in retention, compared to a controlled group matched for age, gender, malocclusion, and treatment duration.Initial weighed-PAR and ICON indices did not differ between the compared groups.According to the ICON index, 50% of patients in both groups were graded as being of moderate complexity, while 36.5% in cancer survivors and 38.5% in the control group involved cases graded as being either difficult or very difficult.Immediately after orthodontic treatment, the weighed-PAR and ICON indices did not differ either.However, after a period of 3 years in retention, the cancer survivors group demonstrated statistically significant increases in the above-mentioned indices [36].

Patient-Reported Outcomes
Three of the located papers elaborated on patient-reported outcomes from cancer survivors subjected to orthodontic treatment.
The oral health-related quality of life (OHRQoL), as assessed with the 14-item Oral Health Impact Profile (OHIP-14) total and impact scores, did not differ between cancer survivors and healthy control patients before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances [34].Only psychological discomfort measured during treatment was significantly higher in cancer survivors.Moreover, in the latter group, males reported a significantly lower OHRQoL during the treatment compared to females, a finding not observed in the control group.A similar finding by Mitus-Kenig et al. [36] was that the assessed patient satisfaction was at a similar level before treatment, at the end of treatment, and following 3 years in retention, despite more post-treatment changes observed in the survivors' group.
Mitus-Kenig et al. [35] compared two groups of cancer survivors; one was treated in a standard manner, while the other was classified as a rapid treatment group.The latter included patients with a risk of hospitalization or oncological examinations potentially influencing orthodontic treatment within a year, who as such were scheduled to finish orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts scores) did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-Ottawa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods,

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods,

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in 5.All studies were allocated stars for the investigated domains, except for Mitus-K et al. [33,35], which could not receive ratings for the "Selection of the non-exposed co and the "Comparability of cohort on basis of design or analysis" domains, since the not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains nificant health concern [1,2].In Europe, it has been estimated that nearly 80% of y individuals diagnosed with cancer survive for a minimum of five years, and in som stances, survival may extend even further [5,6].This prolonged survival is a ribut the ongoing advances in treatment and supportive care programs [7].Therefore, it is expected that some patients who have survived cancer will seek care in orthodont fices.To the best of our knowledge, this is the first systematic review to investigate o dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orthodontic treatment in c survivors varies.Patient groups with a mean treatment duration between 18 an months were reported with final occlusal results similar to those a ained in healthy viduals, while approximating to the mean duration of the orthodontic treatment rep for healthy patients [37].Certain survivor cohorts received treatment for shorter per

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa S 5.All studies were allocated stars for the investigated doma et al. [33,35], which could not receive ratings for the "Selection and the "Comparability of cohort on basis of design or analys not involve comparisons to healthy, "non-exposed" control gr

Discussion
Despite the low frequency of cancer among young popul nificant health concern [1,2].In Europe, it has been estimated individuals diagnosed with cancer survive for a minimum of stances, survival may extend even further [5,6].This prolong the ongoing advances in treatment and supportive care progra expected that some patients who have survived cancer will s fices.To the best of our knowledge, this is the first systematic dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orth survivors varies.Patient groups with a mean treatment du months were reported with final occlusal results similar to tho viduals, while approximating to the mean duration of the orth for healthy patients [37].Certain survivor cohorts received tre Selection of the non-exposed cohort did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, did not differ between these groups before treatment, 2 week ment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa S 5.All studies were allocated stars for the investigated doma et al. [33,35], which could not receive ratings for the "Selection and the "Comparability of cohort on basis of design or analys not involve comparisons to healthy, "non-exposed" control gr

Discussion
Despite the low frequency of cancer among young popul nificant health concern [1,2].In Europe, it has been estimated individuals diagnosed with cancer survive for a minimum of stances, survival may extend even further [5,6].This prolong the ongoing advances in treatment and supportive care progra expected that some patients who have survived cancer will s fices.To the best of our knowledge, this is the first systematic dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orth survivors varies.Patient groups with a mean treatment du months were reported with final occlusal results similar to tho viduals, while approximating to the mean duration of the orth for healthy patients [37].Certain survivor cohorts received tre Ascertainment of exposure orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts scores) did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts scores) did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts sc did not differ between these groups before treatment, 2 weeks and 3 months into ment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in 5.All studies were allocated stars for the investigated domains, except for Mitus-K et al. [33,35], which could not receive ratings for the "Selection of the non-exposed co and the "Comparability of cohort on basis of design or analysis" domains, since the not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains nificant health concern [1,2].In Europe, it has been estimated that nearly 80% of y individuals diagnosed with cancer survive for a minimum of five years, and in som stances, survival may extend even further [5,6].This prolonged survival is a ribut the ongoing advances in treatment and supportive care programs [7].Therefore, it is expected that some patients who have survived cancer will seek care in orthodont fices.To the best of our knowledge, this is the first systematic review to investigate o dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orthodontic treatment in c survivors varies.Patient groups with a mean treatment duration between 18 an months were reported with final occlusal results similar to those a ained in healthy viduals, while approximating to the mean duration of the orthodontic treatment rep for healthy patients [37].Certain survivor cohorts received treatment for shorter per orthodontic intervention in 12 months.The OHRQoL (OHIP-1 did not differ between these groups before treatment, 2 week ment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa S 5.All studies were allocated stars for the investigated doma et al. [33,35], which could not receive ratings for the "Selection and the "Comparability of cohort on basis of design or analys not involve comparisons to healthy, "non-exposed" control gr

Discussion
Despite the low frequency of cancer among young popul nificant health concern [1,2].In Europe, it has been estimated individuals diagnosed with cancer survive for a minimum of stances, survival may extend even further [5,6].This prolong the ongoing advances in treatment and supportive care progra expected that some patients who have survived cancer will s fices.To the best of our knowledge, this is the first systematic dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orth survivors varies.Patient groups with a mean treatment du months were reported with final occlusal results similar to tho viduals, while approximating to the mean duration of the orth for healthy patients [37].Certain survivor cohorts received tre Demonstration that outcome of interest was not present at start of study included patients with a risk of hospitalization or oncological examinations potentially influencing orthodontic treatment within a year, who as such were scheduled to finish orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts scores) did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, included patients with a risk of hospitalization or oncological examinations potentially influencing orthodontic treatment within a year, who as such were scheduled to finish orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts scores) did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, included patients with a risk of hospitalization or oncological examinations poten influencing orthodontic treatment within a year, who as such were scheduled to fi orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts sc did not differ between these groups before treatment, 2 weeks and 3 months into ment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in 5.All studies were allocated stars for the investigated domains, except for Mitus-K et al. [33,35], which could not receive ratings for the "Selection of the non-exposed co and the "Comparability of cohort on basis of design or analysis" domains, since the not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains nificant health concern [1,2].In Europe, it has been estimated that nearly 80% of y individuals diagnosed with cancer survive for a minimum of five years, and in som stances, survival may extend even further [5,6].This prolonged survival is a ribut the ongoing advances in treatment and supportive care programs [7].Therefore, it is expected that some patients who have survived cancer will seek care in orthodont fices.To the best of our knowledge, this is the first systematic review to investigate o dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orthodontic treatment in c survivors varies.Patient groups with a mean treatment duration between 18 an months were reported with final occlusal results similar to those a ained in healthy viduals, while approximating to the mean duration of the orthodontic treatment rep for healthy patients [37].Certain survivor cohorts received treatment for shorter per included patients with a risk of hospitalization or oncologica influencing orthodontic treatment within a year, who as suc orthodontic intervention in 12 months.The OHRQoL (OHIP-1 did not differ between these groups before treatment, 2 week ment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa S 5.All studies were allocated stars for the investigated doma et al. [33,35], which could not receive ratings for the "Selection and the "Comparability of cohort on basis of design or analys not involve comparisons to healthy, "non-exposed" control gr

Discussion
Despite the low frequency of cancer among young popul nificant health concern [1,2].In Europe, it has been estimated individuals diagnosed with cancer survive for a minimum of stances, survival may extend even further [5,6].This prolong the ongoing advances in treatment and supportive care progra expected that some patients who have survived cancer will s fices.To the best of our knowledge, this is the first systematic dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orth survivors varies.Patient groups with a mean treatment du months were reported with final occlusal results similar to tho viduals, while approximating to the mean duration of the orth for healthy patients [37].Certain survivor cohorts received tre

Comparability of cohort on basis on design or analysis
Mitus-Kenig et al. [35] compared two groups of cancer survivors; one was treated in a standard manner, while the other was classified as a rapid treatment group.The la er included patients with a risk of hospitalization or oncological examinations potentially influencing orthodontic treatment within a year, who as such were scheduled to finish orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts scores) did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, Mitus-Kenig et al. [35] compared two groups of cancer survivors; one was treated in a standard manner, while the other was classified as a rapid treatment group.The la er included patients with a risk of hospitalization or oncological examinations potentially influencing orthodontic treatment within a year, who as such were scheduled to finish orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts scores) did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, Mitus-Kenig et al. [35] compared two groups of cancer sur a standard manner, while the other was classified as a rapid tr included patients with a risk of hospitalization or oncological influencing orthodontic treatment within a year, who as such orthodontic intervention in 12 months.The OHRQoL (OHIP-14 did not differ between these groups before treatment, 2 weeks ment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Sc 5.All studies were allocated stars for the investigated domai et al. [33,35], which could not receive ratings for the "Selection o and the "Comparability of cohort on basis of design or analysis not involve comparisons to healthy, "non-exposed" control gro

Discussion
Despite the low frequency of cancer among young popula nificant health concern [1,2].In Europe, it has been estimated individuals diagnosed with cancer survive for a minimum of fi stances, survival may extend even further [5,6].This prolonge the ongoing advances in treatment and supportive care program expected that some patients who have survived cancer will se fices.To the best of our knowledge, this is the first systematic re dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of ortho survivors varies.Patient groups with a mean treatment dur months were reported with final occlusal results similar to thos viduals, while approximating to the mean duration of the ortho for healthy patients [37].Certain survivor cohorts received trea Mitus-Kenig et al. [35] compared two groups of cancer s a standard manner, while the other was classified as a rapid included patients with a risk of hospitalization or oncologi influencing orthodontic treatment within a year, who as su orthodontic intervention in 12 months.The OHRQoL (OHIP did not differ between these groups before treatment, 2 we ment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa 5.All studies were allocated stars for the investigated dom et al. [33,35], which could not receive ratings for the "Selectio and the "Comparability of cohort on basis of design or analy not involve comparisons to healthy, "non-exposed" control g

Discussion
Despite the low frequency of cancer among young popu nificant health concern [1,2].In Europe, it has been estimate individuals diagnosed with cancer survive for a minimum o stances, survival may extend even further [5,6].This prolon the ongoing advances in treatment and supportive care progr expected that some patients who have survived cancer will fices.To the best of our knowledge, this is the first systematic dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of ort survivors varies.Patient groups with a mean treatment d months were reported with final occlusal results similar to th viduals, while approximating to the mean duration of the ort for healthy patients [37].Certain survivor cohorts received tr Mitus-Kenig et al. [35] compared two groups of cancer survivors; one was treated in a standard manner, while the other was classified as a rapid treatment group.The la er included patients with a risk of hospitalization or oncological examinations potentially influencing orthodontic treatment within a year, who as such were scheduled to finish orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts scores) did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, .Clin.Med.2024, 13, x FOR PEER REVIEW 8 of 12 Mitus-Kenig et al. [35] compared two groups of cancer survivors; one was treated in a standard manner, while the other was classified as a rapid treatment group.The la er included patients with a risk of hospitalization or oncological examinations potentially influencing orthodontic treatment within a year, who as such were scheduled to finish orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts scores) did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, Mitus-Kenig et al. [35] compared two groups of cancer survivors; one was treat a standard manner, while the other was classified as a rapid treatment group.The included patients with a risk of hospitalization or oncological examinations poten influencing orthodontic treatment within a year, who as such were scheduled to fi orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts sc did not differ between these groups before treatment, 2 weeks and 3 months into ment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in 5.All studies were allocated stars for the investigated domains, except for Mitus-K et al. [33,35], which could not receive ratings for the "Selection of the non-exposed co and the "Comparability of cohort on basis of design or analysis" domains, since the not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains nificant health concern [1,2].In Europe, it has been estimated that nearly 80% of y individuals diagnosed with cancer survive for a minimum of five years, and in som stances, survival may extend even further [5,6].This prolonged survival is a ribut the ongoing advances in treatment and supportive care programs [7].Therefore, it is expected that some patients who have survived cancer will seek care in orthodont fices.To the best of our knowledge, this is the first systematic review to investigate o dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orthodontic treatment in c survivors varies.Patient groups with a mean treatment duration between 18 an months were reported with final occlusal results similar to those a ained in healthy viduals, while approximating to the mean duration of the orthodontic treatment rep for healthy patients [37].Certain survivor cohorts received treatment for shorter per J. Clin.Med.2024, 13, x FOR PEER REVIEW Mitus-Kenig et al. [35] compared two groups of cancer su a standard manner, while the other was classified as a rapid included patients with a risk of hospitalization or oncologica influencing orthodontic treatment within a year, who as suc orthodontic intervention in 12 months.The OHRQoL (OHIP-1 did not differ between these groups before treatment, 2 week ment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa S 5.All studies were allocated stars for the investigated doma et al. [33,35], which could not receive ratings for the "Selection and the "Comparability of cohort on basis of design or analys not involve comparisons to healthy, "non-exposed" control gr

Discussion
Despite the low frequency of cancer among young popul nificant health concern [1,2].In Europe, it has been estimated individuals diagnosed with cancer survive for a minimum of stances, survival may extend even further [5,6].This prolong the ongoing advances in treatment and supportive care progra expected that some patients who have survived cancer will s fices.To the best of our knowledge, this is the first systematic dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orth survivors varies.Patient groups with a mean treatment du months were reported with final occlusal results similar to tho viduals, while approximating to the mean duration of the orth for healthy patients [37].Certain survivor cohorts received tre Mitus-Kenig et al. [35] compared two groups of cancer survivors; one was treated in a standard manner, while the other was classified as a rapid treatment group.The la er included patients with a risk of hospitalization or oncological examinations potentially influencing orthodontic treatment within a year, who as such were scheduled to finish orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts scores) did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, .Clin.Med.2024, 13, x FOR PEER REVIEW 8 of 12 Mitus-Kenig et al. [35] compared two groups of cancer survivors; one was treated in a standard manner, while the other was classified as a rapid treatment group.The la er included patients with a risk of hospitalization or oncological examinations potentially influencing orthodontic treatment within a year, who as such were scheduled to finish orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts scores) did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, Mitus-Kenig et al. [35] compared two groups of cancer survivors; one was treat a standard manner, while the other was classified as a rapid treatment group.The included patients with a risk of hospitalization or oncological examinations poten influencing orthodontic treatment within a year, who as such were scheduled to fi orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts sc did not differ between these groups before treatment, 2 weeks and 3 months into ment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in 5.All studies were allocated stars for the investigated domains, except for Mitus-K et al. [33,35], which could not receive ratings for the "Selection of the non-exposed co and the "Comparability of cohort on basis of design or analysis" domains, since the not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains nificant health concern [1,2].In Europe, it has been estimated that nearly 80% of y individuals diagnosed with cancer survive for a minimum of five years, and in som stances, survival may extend even further [5,6].This prolonged survival is a ribut the ongoing advances in treatment and supportive care programs [7].Therefore, it is expected that some patients who have survived cancer will seek care in orthodont fices.To the best of our knowledge, this is the first systematic review to investigate o dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orthodontic treatment in c survivors varies.Patient groups with a mean treatment duration between 18 an months were reported with final occlusal results similar to those a ained in healthy viduals, while approximating to the mean duration of the orthodontic treatment rep for healthy patients [37].Certain survivor cohorts received treatment for shorter per J. Clin.Med.2024, 13, x FOR PEER REVIEW Mitus-Kenig et al. [35] compared two groups of cancer su a standard manner, while the other was classified as a rapid included patients with a risk of hospitalization or oncologica influencing orthodontic treatment within a year, who as suc orthodontic intervention in 12 months.The OHRQoL (OHIP-1 did not differ between these groups before treatment, 2 week ment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa S 5.All studies were allocated stars for the investigated doma et al. [33,35], which could not receive ratings for the "Selection and the "Comparability of cohort on basis of design or analys not involve comparisons to healthy, "non-exposed" control gr

Discussion
Despite the low frequency of cancer among young popul nificant health concern [1,2].In Europe, it has been estimated individuals diagnosed with cancer survive for a minimum of stances, survival may extend even further [5,6].This prolong the ongoing advances in treatment and supportive care progra expected that some patients who have survived cancer will s fices.To the best of our knowledge, this is the first systematic dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orth survivors varies.Patient groups with a mean treatment du months were reported with final occlusal results similar to tho viduals, while approximating to the mean duration of the orth for healthy patients [37].Certain survivor cohorts received tre Mitus-Kenig et al. [35] compared two groups of cancer survivors; one was treated in a standard manner, while the other was classified as a rapid treatment group.The la er included patients with a risk of hospitalization or oncological examinations potentially influencing orthodontic treatment within a year, who as such were scheduled to finish orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts scores) did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, .Clin.Med.2024, 13, x FOR PEER REVIEW 8 of 12 Mitus-Kenig et al. [35] compared two groups of cancer survivors; one was treated in a standard manner, while the other was classified as a rapid treatment group.The la er included patients with a risk of hospitalization or oncological examinations potentially influencing orthodontic treatment within a year, who as such were scheduled to finish orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts scores) did not differ between these groups before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in Table 5.All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is a ributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthotreatment characteristics in cancer survivors.The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those a ained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, Mitus-Kenig et al. [35] compared two groups of cancer survivors; one was treat a standard manner, while the other was classified as a rapid treatment group.The included patients with a risk of hospitalization or oncological examinations poten influencing orthodontic treatment within a year, who as such were scheduled to fi orthodontic intervention in 12 months.The OHRQoL (OHIP-14 total and impacts sc did not differ between these groups before treatment, 2 weeks and 3 months into ment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa Scale are presented in 5.All studies were allocated stars for the investigated domains, except for Mitus-K et al. [33,35], which could not receive ratings for the "Selection of the non-exposed co and the "Comparability of cohort on basis of design or analysis" domains, since the not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains nificant health concern [1,2].In Europe, it has been estimated that nearly 80% of y individuals diagnosed with cancer survive for a minimum of five years, and in som stances, survival may extend even further [5,6].This prolonged survival is a ribut the ongoing advances in treatment and supportive care programs [7].Therefore, it is expected that some patients who have survived cancer will seek care in orthodont fices.To the best of our knowledge, this is the first systematic review to investigate o dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orthodontic treatment in c survivors varies.Patient groups with a mean treatment duration between 18 an months were reported with final occlusal results similar to those a ained in healthy viduals, while approximating to the mean duration of the orthodontic treatment rep for healthy patients [37].Certain survivor cohorts received treatment for shorter per J. Clin.Med.2024, 13, x FOR PEER REVIEW Mitus-Kenig et al. [35] compared two groups of cancer su a standard manner, while the other was classified as a rapid included patients with a risk of hospitalization or oncologica influencing orthodontic treatment within a year, who as suc orthodontic intervention in 12 months.The OHRQoL (OHIP-1 did not differ between these groups before treatment, 2 week ment, or following the removal of appliances.

Risk of Bias within Studies
The risk of bias assessments with the Newcastle-O awa S 5.All studies were allocated stars for the investigated doma et al. [33,35], which could not receive ratings for the "Selection and the "Comparability of cohort on basis of design or analys not involve comparisons to healthy, "non-exposed" control gr

Discussion
Despite the low frequency of cancer among young popul nificant health concern [1,2].In Europe, it has been estimated individuals diagnosed with cancer survive for a minimum of stances, survival may extend even further [5,6].This prolong the ongoing advances in treatment and supportive care progra expected that some patients who have survived cancer will s fices.To the best of our knowledge, this is the first systematic dontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orth survivors varies.Patient groups with a mean treatment du months were reported with final occlusal results similar to tho viduals, while approximating to the mean duration of the orth for healthy patients [37].Certain survivor cohorts received tre All studies were allocated stars for the investigated domains, except for Mitus-Kenig et al. [33,35], which could not receive ratings for the "Selection of the non-exposed cohort" and the "Comparability of cohort on basis of design or analysis" domains, since they did not involve comparisons to healthy, "non-exposed" control groups.

Discussion
Despite the low frequency of cancer among young populations, it still remains a significant health concern [1,2].In Europe, it has been estimated that nearly 80% of young individuals diagnosed with cancer survive for a minimum of five years, and in some instances, survival may extend even further [5,6].This prolonged survival is attributed to the ongoing advances in treatment and supportive care programs [7].Therefore, it is to be expected that some patients who have survived cancer will seek care in orthodontic offices.To the best of our knowledge, this is the first systematic review to investigate orthodontic treatment characteristics in cancer survivors.
The retrieved material revealed that the duration of orthodontic treatment in cancer survivors varies.Patient groups with a mean treatment duration between 18 and 20 months were reported with final occlusal results similar to those attained in healthy individuals, while approximating to the mean duration of the orthodontic treatment reported for healthy patients [37].Certain survivor cohorts received treatment for shorter periods, and in some cases the final results were compromised, either because treatment objectives were set as such from the beginning of treatment, as an attempt to mitigate the exacerbation of adverse effects, or as a result of the premature termination of treatment due to a recurrence of the malignancy.Root resorption was reported among the treated cancer survivors but not in the group completing treatment within 12 months [35].A possible explanation could be that a lengthier orthodontic treatment can lead to increased root resorption [38].Oral mucositis-a common finding in cancer survivors-was also a consistent finding among the included studies.Photobiomodulation has been reported to be effective in the treatment of oral mucositis [39].
Although no specific correlation has been observed between the type of malignancy and orthodontic diagnosis, several effects of chemo-and radiotherapy on oral and perioral anatomical structures have been observed [24,25].Impaired root growth and microdontia are the most commonly reported defects [24].Chemotherapy has also been associated with an increased risk for tooth agenesis compared to healthy controls.Other unwanted sequelae include tooth discoloration, arrested tooth development, enamel hypoplasia, premature apexification, and decreased salivary flow rate.Moreover, worse oral hygiene and increased caries experience compared to controls was noted [25].Skeletal growth may also be influenced by anti-cancer therapy.Age, dose exposure, and location seem to be significant factors.The mandible has been reported to be four times more sensitive than the maxilla [40].It has also been observed that antineoplastic treatment may affect occlusion development; increased occurrence of posterior cross-bites has been reported [20].There is also evidence that oncological treatment has a causal relationship with several other inadvertent effects, such as mucositis, affecting every location of the oral mucosa; infections; neurological disturbances and dysgeusia; hyposialia and xerostomia; bleeding tendencies; and osteonecrosis development [41].Longo et al. concluded that antineoplastic therapy in patients with childhood cancer has a negative impact on the periodontium and various microbiological parameters [42].Fifty-three percent of patients who underwent total body irradiation at a young age had a decreased mouth opening and reduced width of translational movements.Also, in 84% of such patients, symptoms of craniomandibular dysfunction were detected [43].The risk of such adverse effects increases in younger children and with radiation dosages more than 4 Gy [40,44,45].Dental agenesis and microdontia have been correlated with the patient age at the time of radiotherapy, dose, and length of irradiation, as well as the tumor site [40].
Mitus-Kening et al. [36] reported a decline in outcome for stability in a 3-year retention period of cancer survivors, which indicates the need for a more extensive follow-up to reduce the risk of post-treatment changes [36].These changes could be attributed to a decreased resistance in tooth movement due to the reduced density of bone following cancer treatment [46].It could also be the result of the impact of chemotherapeutic drugs per se the remodeling of the alveolar bone, which in turn could affect the incidence of postorthodontic treatment changes.Recent systematic reviews have reported on medications that may affect the rate of tooth movement and post-orthodontic treatment changes [47][48][49].Nevertheless, currently, no evidence exists regarding the direct impact of chemotherapyrelated drugs or radiotherapy on the rate of tooth movement, or relapse.
An important finding of the present review was that although complications might arise because of orthodontic treatment, the quality of life of survivors is similar to that of their healthy peers.The oral health-related quality of life (OHRQoL) was not reported to differ between cancer survivors and healthy control patients before treatment, 2 weeks and 3 months into treatment, or following the removal of appliances [34].Only psychological discomfort measured during treatment was significantly higher in cancer survivors.The findings regarding patient satisfaction up to 3 years in retention were similar, despite more post-treatment changes observed in the survivors' group [36].These findings for the survivors having undergone orthodontic treatment are encouraging, since cancer survivors in Europe have been reported to have a lower QoL than their peers [50].
Despite being outside the direct scope of this systematic review, efforts were made by the authors to summarize some points derived from the located information that could be relevant to an orthodontist treating cancer survivors.

•
Orthodontic intervention is well tolerated and should preferably start after consulting with the treating physician, since there is a risk of relapse and cancer recurrence.

•
Reasonable treatment compromises and simple mechanics could be considered in specific cases, keeping the treatment duration limited, and potentially decreasing the risk of root resorption.• The use of appliances that do not interfere with radiologic investigation like MRIs should be considered in coordination with treating physician.

•
Special attention should be given to the prevention and management of oral mucositis.Close follow-up during the retention period would be advisable.

Strengths and Limitations
Despite adhering to the most current methodological guidelines, which constitutes an important strength, this systematic review presents limitations, mainly stemming from the nature of the included studies.Specifically, the limited number of studies, the different oncological diagnoses and treatments of the patients, along with the different orthodontic diagnoses and management, as well as the variability among the outcomes, all significantly increase the heterogeneity among the included studies.All the included studies were retrospective; thus, their results are potentially subject to a bias inherent to the retrospective design.In addition, all these studies were conducted by the same author group in the same country, a fact that may jeopardize the generalizability of the outcomes.Moreover, patient samples may overlap; despite efforts, we were unsuccessful in contacting the author group to gain further details.Therefore, the outcomes should be evaluated cautiously.

Conclusions
Overall, the duration of orthodontic treatment varied among cancer survivors.The occlusal results achieved were similar to those of their healthy peers, though potentially less stable.The OHRQoL did not differ significantly between cancer survivors and healthy individuals treated orthodontically.The literature on this topic is limited and there is a need for larger prospective cohort studies and clinical trials in the field.

Figure 1 .
Figure 1.Prisma diagram of the included studies.Figure 1. Prisma diagram of the included studies.

Figure 1 .
Figure 1.Prisma diagram of the included studies.Figure 1. Prisma diagram of the included studies.

Table 2 .
Databases searched (up to 11 August 2023), strategies used, and hits per database.
(chemotherapy OR chemo OR ctx OR radiotherapy OR radiation OR irradiation OR "x-ray therapy" OR actinotherapy) AND (cancer OR oncol* OR surviv* OR leukemia OR neoplasm* OR tumor OR tumour OR malign*) AND orthodontic*[ti]

85 Cochrane Central Register of Controlled Trials
(chemotherapy OR chemo OR ctx OR radiotherapy OR radiation OR irradiation OR "x-ray therapy" OR actinotherapy) AND (cancer OR oncol* OR surviv* OR leukemia OR neoplasm* OR tumor OR tumour OR malign*) AND orthodontic* in Record Title OR (chemotherapy OR chemo OR ctx OR radiotherapy OR radiation OR irradiation OR "x-ray therapy" OR actinotherapy) AND (cancer OR oncol* OR surviv* OR leukemia OR neoplasm* OR tumor OR tumour OR malign*) AND orthodontic* in Abstract-(Word variations have been searched) 63 Web of Science™ Core Collection (chemotherapy OR chemo OR ctx OR radiotherapy OR radiation OR irradiation OR "x-ray therapy" OR actinotherapy) AND (cancer OR oncol* OR surviv* OR leukemia OR neoplasm* OR tumor OR tumour OR malign*) AND orthodontic* (Topic) Timespan: All years.Search language=Auto

Table 3 .
Excluded records with reasons for exclusion.

Table 3 .
Excluded records with reasons for exclusion.

Table 4 .
Characteristics of the included studies.

Table 5 .
Risk of bias assessment with the Newcastle-Ottawa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.

Table 5 .
Risk of bias assessment with the Newcastle-O awa Scale.