Search Results (291)

Oral lichen planus (OLP) is a chronic immune-mediated disorder affecting the mucous membranes of the oral cavity, characterized by inflammation caused by T-cell-mediated destruction of basal keratinocytes with the potential for malignant transformation. The exact etiology of the disease remains unclear, but as its symptoms may reduce patient quality of life, various treatment modalities have been proposed, generally based on managing symptoms and controlling disease progression. In this narrative review, we examine both conventional therapies (corticosteroids, immunosuppressants, retinoids) and emerging treatment options (photodynamic therapy, low-level laser therapy, and biologics) in terms of their efficacy and limitations. Although corticosteroid therapy remains a cornerstone of treatment, it is not effective in all cases, demonstrating the need to investigate alternative methods; hence, we also present possible future directions for OLP treatment in this study. Full article

Background: Adult patients with a thin buccal cortical plate and fragile periodontal phenotype are at high risk of dehiscence, fenestration and recession during transverse orthodontic expansion. Conventional mechanics often create a cervical compression-dominant environment that exceeds the adaptive capacity of the periodontal ligament (PDL)–bone complex. Objectives: This study proposes an integrative mechanobiological model in which a skeletal-anchorage-assisted loading protocol (Bone Protection System, BPS) transforms expansion into a tension-dominant regime that favours buccal phenotype preservation. Methods: Patient-specific finite element models were used to compare conventional expansion with a BPS-modified force system. Regional PDL stress patterns and crown/apex displacement vectors were analysed to distinguish tipping-dominant from translation-dominated mechanics. A pilot CBCT proof-of-concept (n = 1 thin-phenotype adult) with voxel-based registration quantified changes in maxillary and mandibular alveolar ridge width and buccal cortical plate thickness before and after BPS-assisted expansion. The mechanical findings were integrated with current evidence on compression- versus tension-driven inflammatory and osteogenic pathways in the PDL and cortical bone. Results: FEM demonstrated that conventional expansion concentrates high cervical compressive stress along the buccal PDL and cortical surface, accompanied by bending-like crown–root divergence. In contrast, the BPS protocol redirected forces to create a buccal tensile-favourable region and a more parallel crown–apex displacement pattern, indicative of translation-dominated movement. In the proof-of-concept (n = 1) CBCT case, BPS-assisted expansion was associated with preservation or increase of buccal ridge dimensions without radiographic signs of cortical breakdown. Conclusions: A tension-dominant orthodontic loading environment generated by a skeletal-anchorage-assisted force system may support buccal cortical preservation and vestibular phenotype reinforcement in thin-phenotype patients. The proposed mechanobiological model links these imaging and FEM findings to known molecular pathways of inflammation, angiogenesis and osteogenesis. It suggests a functional biomaterial-based strategy for widening the biological envelope of safe tooth movement. Full article

Background: Patients with a thin gingival phenotype and a narrow buccal alveolar plate are highly susceptible to periodontal complications during orthodontic expansion. Traditional biomechanics often fail to maintain root control in thin alveolar housing. This report presents two clinical cases illustrating soft- and hard-tissue responses to a novel biomechanical approach, the Bone Protection System (BPS), designed to reduce buccal cortical overload during expansion. Case Presentation: Two adult patients with a thin gingival phenotype assessed by a standardized periodontal probe transparency test and narrow alveolar ridges underwent orthodontic expansion. Patient 1 was treated with the full BPS protocol in both arches. Patient 2 received BPS only in the maxilla, while the mandible was treated conventionally, creating an intra-individual control model under identical systemic conditions. Soft-tissue phenotype and cortical plate response were evaluated clinically and radiographically when applicable. Results: In Patient 1 clinically, the vestibular phenotype showed clear thickening and stabilization. In Patient 2, the maxillary arch treated with BPS exhibited progressive thickening of the vestibular phenotype, whereas the mandible treated conventionally presented thinning and increased translucency—features consistent with buccal compression in thin alveolar bone. No soft- or hard-tissue augmentation procedures were performed in either case. Conclusions: The Bone Protection System may contribute to improved periodontal safety during orthodontic expansion in thin-biotype patients by reducing buccal cortical loading and supporting adaptive soft-tissue and bone responses. Preliminary observations suggests that BPS has potential value for possibly expanding the biological limits of safe tooth movement. Further studies on larger cohorts are warranted. Full article

Background: Mechanical loading is a fundamental regulator of bone remodelling; however, the mechanotransduction mechanisms governing alveolar bone adaptation under tensile-dominant orthodontic loading remain insufficiently defined. In particular, the molecular pathways associated with tension-driven cortical modelling in the periodontal ligament (PDL)–bone complex have not been systematically interpreted in the context of advanced biomechanical simulations. Methods: A nonlinear finite element model of the alveolar bone–PDL–tooth complex was developed using patient-specific CBCT data. Three loading configurations were analysed: (i) conventional orthodontic loading, (ii) loading combined with corticotomy alone, and (iii) a translation-dominant configuration generated by the Bone Protection System (BPS). Pressure distribution, displacement vectors, and stress polarity within the PDL and cortical plate were quantified across different bone density conditions. The mechanical outputs were subsequently interpreted in relation to established mechanotransductive molecular pathways involved in osteogenesis and angiogenesis. Results: Conventional loading generated compression-dominant stress fields within the marginal PDL, frequently exceeding physiological thresholds and producing moment-driven root displacement. Corticotomy alone reduced local stiffness but did not substantially alter stress polarity. The BPS configuration redirected loads toward a tensile-favourable mechanical environment characterised by reduced peak compressive pressures and parallel (translation-dominant) displacement vectors. The predicted tensile stress distribution is compatible with activation profiles of key mechanosensitive pathways, including integrin–FAK signalling, Wnt/β-catenin–mediated osteogenic differentiation and HIF-1α/VEGF-driven angiogenic coupling, suggesting a microenvironment that may be more conducive to cortical apposition than to resorption. Conclusions: This study presents a computational–molecular framework linking finite element–derived tensile stress patterns with osteogenic and angiogenic signalling pathways relevant to alveolar bone remodelling. The findings suggestthat controlled redirection of orthodontic loading toward tensile domains may shift the mechanical environment of the PDL–bone complex toward conditions associated with osteogenic than resorptive responses providing a mechanistic basis for tension-induced cortical modelling. This mechanobiological paradigm advances the understanding of load-guided alveolar bone adaptation at both the tissue and molecular levels. Full article

Background: Non-syndromic cleft lip/palate (NCL/P) is a prevalent congenital anomaly. Despite an unclear epidemiological link between orofacial clefts and dental caries, genetic studies suggest that polymorphisms in taste receptor genes may influence caries risk. Objectives: This study had two primary objectives: (1) to compare SNPs in NCL/P-associated genes (IRF6, FOXE1) between Kuwaiti NCL/P cases and controls, and (2) to explore whether variants in caries-associated (KLK4, DSPP) and taste receptor (TAS1R2, TAS2R38) genes are associated with dental caries susceptibility in individuals with NCL/P, independent of overall caries prevalence. Methods: A case–control design was employed, with 25 NCL/P cases and 25 unaffected controls recruited from a Dental Craniofacial Clinic in Kuwait. Genomic DNA was extracted from buccal swabs, and SNP genotyping was performed using real-time PCR for genes related to NCL/P, dental caries, and taste perception. Caries status was assessed using the dmft/DMFT scoring system. The genotyped genes included NCL/P-related (IRF6, FOXE1), caries-related (KLK4, DSPP), and taste receptor genes (TAS1R2, TAS2R38). Results: At nominal significance, KLK4, DSPP, and TAS1R2 showed associations with NCL/P status, while IRF6 and FOXE1 did not. After applying Benjamini–Hochberg FDR correction across 10 SNPs, no allele- or genotype-level association remained significant (q < 0.05). The strongest signal was KLK4 rs2235091 (allele-level p = 0.016; q = 0.159). An exploratory age- and sex-adjusted logistic model for KLK4 suggested a possible effect (aOR 0.40; 95% CI 0.18–0.87; p = 0.021). Within-group analyses of caries burden revealed no associations that survived FDR control (lowest q = 0.056 for FOXE1 in controls). Conclusions: After controlling for multiple testing, no SNP showed a statistically significant association with NCL/P or caries burden. Nominal signals for KLK4, DSPP, and TAS1R2 did not survive FDR correction; an exploratory adjusted model suggested a possible KLK4 effect, but this requires cautious interpretation. The small sample size is a key limitation, and the findings highlight the need for larger, well-powered studies to clarify genetic contributions to NCL/P and caries risk. Full article

Glucose-dependent insulinotropic polypeptide (GIP) was the first incretin hormone identified, best known for promoting glucose-stimulated insulin secretion. Increasing evidence has expanded its physiological relevance beyond glucose metabolism, revealing a significant role for GIP in the gut–bone axis. In vitro studies demonstrate that GIP inhibits osteoclast differentiation and activity while promoting osteoblastic bone formation. Findings from genetic animal models and human variant analyses further support the essential role of endogenous GIP signaling in maintaining bone mass and quality. Exogenous administration of GIP suppresses the bone-resorption marker C-terminal telopeptide of type I collagen (CTX) and increases the bone-formation marker procollagen type I N-terminal propeptide (P1NP) in healthy individuals, reflecting an acute shift toward reduced bone resorption and enhanced bone formation. Moreover, GIP confers protection against bone deterioration in multiple pathological conditions, including postmenopausal osteoporosis, inflammatory bone loss, obesity, and diabetes, etc., suggesting therapeutic potential beyond physiological contexts. Recent evidence also shows that GIP attenuates orthodontic tooth movement by limiting mechanically induced osteoclast activity, highlighting its broader skeletal actions. In this review, we summarize recent advances regarding the role of GIP in bone metabolism, integrating evidence from cellular studies, animal models and human investigations, and discuss future directions for GIP-based interventions. Full article

Bone remodeling is maintained through the coordinated actions of osteoblasts, osteoclasts, and osteocytes, among which osteocytes serve as major regulators of osteoclast-mediated bone resorption through the receptor activator of the nuclear factor-κB ligand (RANKL)–osteoprotegerin (OPG) signaling axis. While molecular signals regulating osteocytic RANKL-OPG expression are fairly understood, how post-transcriptional mechanisms impact osteocyte function remains poorly defined. HuR (human antigen R) encoded by Elavl1 (embryonic lethal abnormal vision-like 1), a ubiquitously expressed RNA-binding protein, is known for stabilizing AU-rich element-containing transcripts involved in inflammatory and stress responses; however, its role in osteocyte-derived bone resorption is unknown. In this study, we examined the effect of HuR loss on osteocyte–osteoclastogenesis. Short hairpin RNA (shRNA)-mediated HuR knockdown in MLO-Y4 osteocyte-like cells resulted in a significant increase in OPG mRNA and its protein expression, whereas RANKL levels remained unchanged, leading to a significantly reduced RANKL/OPG ratio. Both co-culture and conditioned-medium assays demonstrated that HuR-deficient osteocytes produced a markedly diminished osteoclastogenic environment. Actinomycin D chase experiments showed no alteration in OPG mRNA decay kinetics, and RNA immunoprecipitation (RIP)-PCR failed to detect HuR–OPG interactions, indicating that HuR regulates OPG expression through indirect mechanisms rather than mRNA binding. These findings identify HuR as an indirect regulator of osteocyte-derived OPG expression that impacts osteoclast differentiation and reveal a previously unrecognized mechanism by which HuR contributes to bone remodeling. Full article

Background/Objectives: Obstructive sleep apnea (OSA) is a prevalent sleep-related breathing disorder characterized by repeated episodes of upper airway obstruction during sleep, leading to intermittent hypoxia and fragmented sleep architecture. Orofacial myofunctional therapy (OMT) has emerged as a promising non-invasive approach to improving airway patency in individuals with mild-to-moderate OSA. However, the role of sleep ergonomics—including sleep posture and pillow support—in enhancing OMT outcomes remains underexplored. This study aimed to evaluate whether ergonomic interventions could augment the therapeutic effects of OMT in adult patients with mild-to-moderate OSA. Methods: A 12-week prospective cohort study was conducted involving 60 adult participants diagnosed with mild-to-moderate OSA. All participants underwent a structured orofacial myofunctional therapy (OMT) program comprising exercises for tongue elevation, lip seal enhancement, and soft palate strengthening. In addition, ergonomic instructions were provided regarding optimal sleeping posture and pillow adjustment. Compliance with ergonomic practices was monitored weekly using infrared night-vision cameras and reviewed by a blinded sleep technician. Pre- and post-intervention assessments included apnea–hypopnea index (AHI), Pittsburgh Sleep Quality Index (PSQI), and Ep-worth Sleepiness Scale (ESS). Results: Statistically significant improvements were observed in all measured parameters following the intervention. AHI scores reduced from 18.2 ± 4.5 to 10.6 ± 3.9 events/hour (p < 0.001), PSQI scores improved from 11.3 ± 2.1 to 6.5 ± 1.8 (p < 0.001), and ESS scores declined from 13.7 ± 2.6 to 7.4 ± 2.0 (p < 0.001). Participants with high adherence to ergonomic recommendations demonstrated significantly greater clinical improvements compared to less adherent individuals. Conclusions: The combination of ergonomic sleep posture interventions with OMT was associated with positive improvements in sleep-related outcomes, comparable to or in some cases better than those reported in previous studies evaluating these interventions independently. As an observational cohort without a control arm, this study cannot establish causality but provides preliminary evidence to guide the design of future randomized clinical trials. Full article

The incretin hormone glucose-dependent insulinotropic polypeptide (GIP) promotes insulin secretion, lowers blood glucose levels, and is increasingly linked to bone remodeling. Native GIP is quickly inactivated by the enzyme dipeptidyl peptidase-4 (DPP-4), whereas (D-Ala²)GIP is a novel GIP analog engineered to resist DPP-4 degradation. Tumor necrosis factor-alpha (TNF-α), a key proinflammatory cytokine, promotes osteoclastogenesis and is notably upregulated during orthodontic tooth movement (OTM). This study aimed to evaluate the effects of (D-Ala²)GIP on TNF-α-induced osteoclast formation and bone resorption in vivo, as well as on OTM and related root resorption. Mice received daily supracalvarial injections of TNF-α with or without (D-Ala²)GIP for 5 days. The (D-Ala²)GIP-treated group showed significantly reduced osteoclast formation, bone resorption, and expression of osteoclastic markers TRAP and cathepsin K, compared to the group that received TNF-α alone. OTM was induced in mice by applying a nickel-titanium closed-coil spring, and mice were treated with either phosphate-buffered saline (PBS) or (D-Ala²)GIP every 2 days. After 12 days, the (D-Ala²)GIP-treated group showed significantly reduced tooth movement and fewer osteoclasts and odontoclasts on the compression side compared to the PBS control. These findings suggest that (D-Ala²)GIP inhibits OTM, potentially by suppressing TNF-α-driven osteoclastogenesis and bone resorption. Full article

Background: This narrative review synthesizes evidence on AI for orthodontic malocclusion diagnosis across five imaging modalities and maps diagnostic metrics to validation tiers and regulatory readiness, with focused appraisal of Class III detection (2019–2025). Key algorithms, datasets, clinical validation, and ethical/regulatory considerations are synthesized. Methods: PubMed, Scopus, and Web of Science were searched for studies published January 2019–October 2025 using (“artificial intelligence”) AND (“malocclusion” OR “skeletal class”) AND “cephalometric.” Records were screened independently by two reviewers, with disagreements resolved by consensus. Eligible studies reported diagnostic performance (accuracy, area under the receiver operating characteristic curve (AUC), sensitivity/specificity) or landmark-localization error for AI-based malocclusion diagnosis. Data on dataset size and validation design were extracted; no formal quality appraisal or risk-of-bias assessments were undertaken, consistent with a narrative review. Results: Deep learning models show high diagnostic accuracy: cephalogram classifiers reach 90–96% for skeletal Class I/II/III; intraoral photograph models achieve 89–93% for Angle molar relationships; automated landmarkers localize ~75% of points within 2 mm. On 9870 multicenter cephalograms, landmarking achieved 0.94 ± 0.74 mm with ≈89% skeletal-class accuracy when landmarks fed a classifier. Conclusion: AI can reduce cephalometric tracing time by ~70–80% and provide consistent skeletal classification. Regulator-aligned benchmarks (multicenter external tests, subgroup reporting, explainability) and pragmatic open-data priorities are outlined, positioning AI as a dependable co-pilot once these gaps are closed. Full article

Airway obstruction may lead to dentofacial dysmorphogenesis, with severity influenced by age, duration, and extent of obstruction. Aims: to evaluate long-term craniofacial changes in children with a history of mouth breathing, comparing outcomes between those treated with lymphoid tissue removal or with medication, and considering treatment age. Materials and Methods: Fifty-seven patients with a mean age of 19.09 years (range: 15.1–25.2 years) who had been evaluated in an earlier study (T1) were recalled at an average of 13 years follow-up (T2) and classified into a surgical group (n = 34), who had an adenoidectomy, and a non-surgical group (n = 23) treated with medication. Lateral cephalograms were obtained and compared with the original pre-treatment records. Control groups were included, matching the subjects in both groups for age and sex. Statistical analyses included group comparisons and associations among variables. Results: Significant improvement in both treatment groups were observed for the gonial angle (Ar-Go-Me), facial convexity (S-N-Me) and facial height (N-Gn), but T2-T1 changes in the surgical group were statistically significantly greater than in the medical therapy group. The palatal plane inclination to the horizontal (PP/H) and the mandibular plane inclination (MP/H) and to cranial base (MP/SN) were significantly improved in both groups (0.001 < p < 0.01). Conclusions: Both surgical and medical treatment of airway obstruction resulted in the reversal of the harmful effect of the obstruction. However, adenoidectomy was associated with greater improvements, possibly because the original obstruction was more severe and longer-standing. The results underline the importance of early recognition and management of airway obstruction to mitigate developmental orofacial dysmorphology. Full article

Introduction: The aim of this study was to evaluate the effect of corticotomy incision depth on tooth movement and stress distribution in the periodontal ligament (PDL) during orthodontic expansion using finite element analysis (FEA). The demand for accelerated and biologically safe orthodontic techniques has highlighted the importance of understanding biomechanical responses to surgical adjuncts like corticotomy. Objective: The aim of this study is to assess the effect of corticotomy depth on tooth movement and periodontal ligament stress distribution during orthodontic treatment using finite element analysis. Materials and methods: A 3D FEM model was developed based on CBCT and intraoral scans to replicate anatomical structures and simulate clinical orthodontic scenarios. Four conditions were analyzed: no corticotomy and corticotomy incisions of 1 mm, 2 mm, and 3 mm depths, applied between roots and above the apex region. Different cortical bone densities were tested using Young’s modulus values (12,500 MPa–27,500 MPa). Stress and displacement values were measured in both the crown and root regions. Results: The 3 mm corticotomy, penetrating through the cortical plate into the cancellous bone, significantly increased crown displacement (up to 26% in low-density bone) and altered root tipping patterns, reducing root movement relative to the crown. Shallower incisions (1–2 mm) had minimal effects. Despite increased movement, stress concentration in the cervical PDL region remained high across all scenarios, particularly in the premolar area, exceeding the 4.7 kPa threshold associated with tissue ischemia. Conclusions: Corticotomy depth is a critical factor for optimizing orthodontic tooth movement. Penetration into cancellous bone (3 mm) appears necessary to induce both: not only the Regional Acceleratory Phenomenon (RAP) but also to enhance displacement. However, this approach does not significantly reduce cervical PDL stress and offers limited periodontal protection. Individual planning based on bone density, morphology, and anatomical limitations is essential for balancing treatment efficiency and periodontal safety. Full article

Objective: To evaluate changes in maxillary incisor inclination before and after orthodontic treatment in adults with different vertical facial patterns (normodivergent, hypodivergent, hyperdivergent) and to assess the relationship of incisor inclination to facial and growth axes using cephalometric and photographic records. Materials and Methods: This retrospective study included 144 non-growing patients (96 females, 48 males) with available pre- and post-treatment lateral cephalograms and smiling profile photographs. Patients were classified into three groups based on mandibular plane angle (MP/SN): normodivergent (n = 66), hypodivergent (n = 35), and hyperdivergent (n = 43). Angular measurements assessed maxillary incisor inclination and growth/facial axes. Clinical crown angulation (CCA) was evaluated from profile photographs. Statistical analyses included paired t-tests, ANOVA with Bonferroni post hoc tests, and Pearson correlation. Results: No significant changes in maxillary incisor inclination were observed post-treatment in any of the groups. Significant skeletal changes were noted in the hypodivergent group, including increases in MP/SN (p = 0.011) and IMPA (p = 0.014). Intergroup comparison revealed significant differences in changes in Facial Axis/H (p = 0.020) and MP/SN (p = 0.025). Correlations between CCA and skeletal axes were more pronounced in normo- and hypodivergent groups, while hyperdivergent patients showed no significant associations. Conclusions: These findings suggest that the stability of maxillary incisor inclination reflects controlled torque mechanics during treatment. In normo- and hypodivergent patients, skeletal axes may help guide esthetic incisor positioning; however, in hyperdivergent patients, soft tissue and smile evaluation should play a greater role when determining final incisor inclination. Full article

Ions released from denture base resins under oral conditions may affect biocompatibility and material stability, particularly at low pH. This study quantified inorganic ion release from three denture base resins—conventional heat-cured PMMA, pre-polymerised CAD/CAM-milled PMMA, and a 3D-printed resin—under simulated oral conditions. Disc specimens (n = 3 per group) were immersed in artificial saliva at pH 4.0 or 7.0 (37 °C) for 24 h or 30 d. Eluates were analysed for Ca, K, Mg, Na, Ti, Fe (ICP-OES) and Zn, Ni, Cu, Cr, Cd, Pb (ICP-MS). Solution concentrations are reported in mg L⁻¹ or µg L⁻¹; cumulative release is normalised per g of resin (mg g⁻¹). Ca, Na, K, Mg, Zn, Ni, Cu, Cr, Fe and Ti were detected; Cd and Pb were below the detection limit. After 30 d at pH 4.0, total release ranked: conventional ≈ 2.8 mg g⁻¹ > 3D-printed ≈ 1.2 mg g⁻¹ > CAD/CAM ≈ 0.6 mg g⁻¹; values were lower at pH 7.0. Material and pH significantly affected most ions (p < 0.001), whereas time affected only Na. Metals were in the µg L⁻¹ range (Ni ≈ 0.008 mg L⁻¹). CAD/CAM showed the lowest total release, consistent with higher chemical stability under simulated oral conditions; 3D-printed was intermediate, and conventional PMMA the highest. Full article

Background/Objectives: This study aimed to evaluate the functional adaptation of the masseter muscle in growing individuals after one year of orthodontic treatment by assessing changes in its thickness. Methods: Twenty children with a mean age of 10.4 ± 2.1 years undergoing orthodontic treatment were monitored over one year. Ultrasonographic measurements of masseter muscle thickness were taken before the commencement of orthodontic treatment and one year later. Eighteen orthodontically untreated children with a mean age of 9.9 ± 2.0 years served as the control group; their masseter muscle thickness was measured at baseline and after the same follow-up period. Comparisons were made between the two groups. Results: At baseline, the mean masseter muscle thickness was 11.4 ± 1.3 mm in the control group and 11.7 ± 1.4 mm in the treatment group. After one year, children in the untreated control group showed an average increase of 0.5 ± 0.6 mm (p < 0.001) in the thickness of the masseter muscle, whereas those undergoing orthodontic treatment exhibited an average decrease of 0.6 ± 0.7 mm (p < 0.001). Multiple regression analysis accounting for age, gender, and initial masseter muscle thickness indicated that orthodontic treatment resulted in a reduction in masseter muscle thickness by 1.1 mm (p < 0.001) compared with the untreated control group. Conclusions: Orthodontic treatment may influence the development of the masticatory muscles. In our sample, the masseter muscle showed an estimated atrophy of approximately 9% after one year of orthodontic treatment compared with the thickness it would likely have achieved in the absence of any orthodontic intervention. Full article