Search Results (12)

(1) The purpose of this study is to relate the bidimensional and tridimensional measures of the palate to the vertical facial pattern defined by the angle “SN-MP” between the mandibular plane and the anterior cranial base (Sella–Nasion/mandibular plane angle) in skeletal Class II untreated patients. Furthermore, the same palatal measures were used to compare Class II with Class I subjects. (2) A sample of 197 Class II Caucasian subjects (112 females and 85 males) with untreated skeletal Class II was collected retrospectively (from a private dental clinic specialized in orthodontics) and divided into two main groups according to the ANB angle: 74 Class I patients (0° ≤ ANB ≤ 4°) and 123 Class II patients (ANB > 4°). Class II subjects were furthermore divided into three groups depending on the angle SN-MP. Lateral cephalograms and digital 3D maxillary dental scans were available. Bidimensional and tridimensional measures were taken on each maxillary dental scan. The differences among the groups were analyzed for significance using a variance analysis. (3) A decrease in the posterior palatal height and an increase in the palatal surface area in Class I subjects were reported. The results showed a change in upper arch form, with a greater intermolar width in patients with a low SN-MP angle and a smaller one in high-angle patients. The more a Class II subject tended towards high-angle divergence, the narrower the palate was. (4) A greater posterior palatal height was found in Class II malocclusion, while greater surface area was noted in Class I malocclusion. In addition to this result, another statistical significance was detected in Class II malocclusion: the intermolar distance was greater in hypodivergent than in hyperdivergent patients. Similar volume values were noted across different malocclusions and vertical divergence groups. Palatal width seemed to be related to vertical facial pattern, while palatal height and area seemed to be related to sagittal malocclusions. These findings underscore the importance of considering palatal morphology variations in designing individualized orthodontic treatments, thereby improving patient-specific outcomes and broadening our understanding of skeletal Class II malocclusion. Full article

Background: Obstructive sleep apnea is a sleep-related breathing disorder associated with craniofacial morphology and dental arches. The aim of this study was to evaluate the correlation between obstructive sleep apnea and the morphometry of dental arches and upper airways. Methods: Forty patients were enrolled in the study, and the polysomnographic parameters evaluated were the apnea hypopnea index (AHI) and the oxygen desaturation index (ODI). Dental measurements taken from the 3D models included anterior arch widths, posterior arch widths, maxillary and mandibular arch lengths, and palatal surface area. A cone beam computed tomography (CBCT) evaluation was also performed. Results: In patients with moderate OSA, posterior maxillary width was significantly correlated with both minimal airway area (rho = 0.65, p < 0.01) and its transverse diameter (rho = 0.68, p < 0.01). Similarly, in patients with severe OSA, posterior maxillary width showed a significant correlation with total airway volume (rho = 1, p < 0.01), minimal airway area (rho = 1, p < 0.01), and its transverse diameter (rho = 1, p < 0.01). Conclusions: Craniofacial morphology and malocclusion can contribute to obstructive sleep apnea syndrome. Full article

Atypical swallowing has a high incidence in growing subjects. Orthopedic treatment with orthodontic appliances and speech therapy are the main approaches to this problem. The aim of this prospective study was to evaluate the changes in the dental arches induced by one year of treatment with the Froggy Mouth myofunctional appliance designed to correct atypical swallowing. In total, 16 patients with atypical swallowing were instructed to use the Froggy Mouth appliance. A digital intraoral impression was taken at baseline (T0). The Froggy Mouth appliance had to be used for 15 min/day throughout the treatment period. At the end of the first year of treatment (T1), another impression was taken with the same intraoral scanner. Digital casts of the T0 and T1 impressions were obtained using software and the two casts were superimposed to record the following measurements: upper intercanine distance, upper arch diameter, upper arch width, overbite and overjet. The data were statistically analyzed (significance threshold: p < 0.05). Student’s t-test was used to compare pre- and post-treatment measurements. Linear regressions were performed to assess the influence of arch width on anterior and posterior diameters. A significant increase was found for the upper arch diameters (p < 0.05), whereas no statistically significant difference was found for the incisor relationship (overjet/overbite) (p > 0.05). To date, the efficacy of this appliance has not been extensively studied. According to the present prospective study, the Froggy Mouth protocol could be a valuable method as a myofunctional therapy for atypical swallowing, but further studies are needed to confirm these preliminary results. Full article

Background and Objectives: The aim of this study was to evaluate the correlation between the mandibular arch shape and the vertical skeletal pattern in growing patients. Materials and Methods: A total of 73 Caucasian patients (33 males and 40 females; mean age 9.4) were retrospectively enrolled from a pool of patients treated in chronological order at the Department of Orthodontics, University of Foggia, Italy, from April 2018 to December 2021. Each patient received a laterolateral radiograph and a digital scan of the dental arch. Eight cephalometric parameters (lower gonial angle, intermaxillary angle, divergence angle, Wits index, Jarabak ratio, OP-MP angle, PP-OP angle, and ANB) and five dental measurements (posterior mandibular arch width, anterior mandibular arch width, mandibular occlusal angle, posterior width on distobuccal molar cusps, and molar angle) were analyzed and then compared. A Spearman’s rho correlation test between the cephalometric measurements and the dental measurements was performed. Statistical significance was set at p < 0.05. Results: A negative statistically significant correlation was found between the Jarabak ratio and the intermolar angle; a statistically significant correlation was also observed between the Wits index, the posterior mandibular width, and the occlusal mandibular angle; the ANB angle and the occlusal mandibular angle; the intermaxillary angle (PP-PM) and the mandibular occlusal angle, posterior mandibular width on the disto-vestibular cusp, and the intermolar angle; and the OP-MP angle and mandibular occlusal angle and the posterior mandibular width on the disto-vestibular cusp. Conclusions: The mandibular arch form may be related to certain predisposing features in craniofacial morphology, such as jaw divergence, the Jarabak ratio, and the intermaxillary angle. Full article

Arch forms in orthodontics are considered to affect occlusal stability. This study’s subjects were 47 patients (Class III S group) who visited the Chiba Dental Center of Tokyo Dental College and were surgical orthodontic cases, and 60 patients with Class I malocclusion were selected as the control group. A mandibular model of each subject was plotted with each tooth on a digitizer. The clinical bracket points of each tooth were plotted, and intercanine and intermolar measurements were taken. The least squares method was used to fit a quartic equation, and the arch form was drawn. The Class IIIS group was divided by Wits appraisal and facial pattern into a dolichofacial or brachyfacial pattern, and arch forms were compared. The results show that the Class IIIS group had a significantly smaller intermolar width, canine depth, and molar depth and a significantly larger canine W/D ratio. In those with a dolichofacial pattern, the anterior curve of the arch form tended to be flat and the posterior curve narrower. This is because, in skeletal mandibular prognathism, the mandibular anterior shows lingual tipping, and the molars show palatal tipping due to dental compensation, and it was inferred that this tendency was higher in high-angle cases. Full article

Background: Numerous studies have investigated the applicability of Pont’s index using a variety of selection criteria. The morphology of teeth and the shapes of the face are significantly influenced by racial, cultural, and environmental factors, so the current study focused on these demographics. Methods: This study is a retrospective study and included one hundred intraoral scanned images selected from patients seeking orthodontic treatment. Medit design software was used to obtain the real measurements and compare them to the predicted values from Pont’s index. Paired t tests were used to test the validity of Pont’s index, and regression equations were advocated to predict the inter-molar, inter-premolar, and anterior arch widths via SPSS version 25. Results: There were significant differences between the real anterior, inter-premolar, and inter-molar widths and the predicted values obtained from Pont’s index, and there were weak positive correlations between the real values and the predicted values from Pont’s index. Conclusions: Pont’s index is not reliable to predict the arch widths for the Kurdish population, and new formulas are advocated. Hence, space analysis, malocclusion treatment, and arch expansion therapy should all take into account these results. Therefore, the derived equations may have further positive effects on diagnoses and treatment preparation. Full article

Background: The objective of this retrospective study was to analyze the morphological changes of the upper arch after two protocols of expansion, the Invisalign® First system and rapid maxillary expansion (RME), in mixed dentition by means of geometric morphometric analysis (GMM). Methods: Digital dental casts of 32 children treated either with RME (RME group: 17 subjects; mean age 8.1 years) or the First system (First group: subjects; mean age 8.4 years) were collected. For both the RG and FG, pre-(T1) and post-treatment(T2) digital models were created. A total of 14 landmarks were digitized and GMM was applied. Procrustes analysis and principal component analysis (PCA) were performed. Results: The PC1 resulting from the T2–T1 comparison in the RG g showed statistically significant morphological changes in the posterior region of the upper arch shape, without significant variations in the anterior region. The comparison of the T2–T1 changes in the FG showed an increase in the transverse dimension at the level of the canine and the first deciduous molar widths, with morphological variation in the anterior region due to frontal teeth alignment. Conclusions: The First system induced shape modifications of the upper arch during expansion in contrast to RME. The FG presented an improvement in the maxillary arch shape, while the RG maintained the initial triangular shape. Full article

This study aimed to analyze the efficacy of maxillary oral appliance (MOA) designs on respiratory variables during sleep. At baseline, 23 participants underwent a sleep test with a portable device for two nights and were categorized as participants with mild obstructive sleep apnea (mild-OSA) (n = 13) and without OSA (w/o-OSA) (n = 10). Three types of MOAs, standard-OA (S-OA), palatal covering-OA (PC-OA), and vertically increasing-OA (VI-OA), were each worn for three nights, and sleep tests with each MOA were performed with a portable device for two nights. Based on the average of the respiratory event index (REI) values for the two nights for each MOA, w/o-OSA participants with an REI ≥ 5.0 were defined as the exacerbation group and those with an REI < 5.0 as the non-exacerbation group. In mild-OSA participants, an REI ≥ 15.0 or REI ≥ baseline REI × 1.5 were defined as the exacerbation group and those with an REI < 15.0 and REI < baseline REI × 1.5 were defined as the non-exacerbation group. The percentage of the exacerbation and non-exacerbation groups with MOA was evaluated in the w/o-OSA and mild-OSA participants. The maxillary and mandibular dental-arch dimension was compared by dentition model analysis. The exacerbation group in w/o-OSA participants (n = 10) comprised 10.0% participants (n = 1) with S-OA, 40.0% (n = 4) with PC-OA, and 30.0% (n = 3) with VI-OA. The exacerbation group in the mild-OSA participants (n = 13) comprised 15.4% subjects (n = 2) with S-OA, 23.1% (n = 3) with PC-OA, and 23.1% (n = 3) in VI-OA. In the model analysis for w/o-OSA, the posterior dental arch width was significantly greater in the exacerbation group than in the non-exacerbation group wearing S-OA (p < 0.05). In addition, the ratio of the maxillary to mandibular dental arch width (anterior dental arch width) was significantly greater in the exacerbation group than in the non-exacerbation group for both PC-OA and VI-OA (p < 0.05). In mild-OSA, the maxillary and mandibular dental arch lengths and the ratio of maxillary to mandibular dental arch width (posterior dental arch width) were significantly smaller in the exacerbation group than in the non-exacerbation group for S-OA (p < 0.05). This study confirmed that wearing an MOA by w/o-OSA and mild-OSA participants may increase the REI during sleep and that PC-OA and VI-OA may increase the REI more than S-OA. The maxillary and mandibular dental-arch dimensions may affect the REI when using an MOA. Full article

The aim of this retrospective study was to compare the efficiency of two biologically oriented devices in achieving maxillary expansion: Rapid Palatal Expander (RPE) and Nitanium Palatal Expander-2 (NPE-2). Thirty-six subjects, divided in two equal groups, were included in this study. Maxillary dental arches were scanned using Trios 3 shape^®, in order to perform a digital analysis of 3D models. The models were analyzed using Autodesk Fusion 360^® and Meshmixer^®. All data obtained from analysis of pre-treatment and post-treatment models were processed using Prism^® software. The anterior arch width, the posterior arch width, the palate height, and palatal surface were measured to evaluate differences between the devices. A D’Agostino–Pearson normality test was done to check the data. A non-parametric t-test was used to compare the anterior and posterior arch width between the two groups, while a parametric t-test was used to compare the palatal height measurements between the two groups. The p-value was calculated. The limit value fixed was 0.05. Palatal width and surface showed a significant increase in both groups, but no significant changes in palatal height were found. The data processed showed that there were no significant differences between the devices (ΔREP−ΔNPE) in variation of anterior arch width, there were no significant differences in variation of posterior arch width and there were no significant differences in variation of palatal height. The comparison between the two groups showed that both methods were equally effective in correcting transverse defect. Full article

The chance to critically and microscopically inspect the quality of bonded restorations once they are delivered to the patient after several pre-cementation steps is rare or nonexistent. Replicas of in-service restorations can provide a wealth of information on the integrity of the restorations and moreover make it possible to bring this information to the laboratory for further detailed analysis. This study aimed to characterize the epoxy replicas of 27 cemented monolithic yttria-stabilized zirconia crowns of the maxillary and mandibular arch to assess surface roughness, topography, and symmetry. The topography of the facial, lingual, and occlusal/incisal surfaces of each crown was observed under the optical microscope and further characterized using the scanning electron microscope. Surface roughness measurements were performed using the atomic force microscope. The optical microscope was used to measure the golden proportion and visible width of the anterior maxillary crowns. Surface damage consistent with unpolished adjustment was identified mostly in the occlusal surface of the posterior teeth. Other irregularities, such as scratch marks, small pits, and coarse pits were also found. The surface roughness had great variability. Not all of the anterior maxillary and mandibular teeth followed the golden proportion concept. This study design allows in vitro characterization of in-service restorations. It provides a framework for using replicas for early identification of patterns or features that can trigger fracture and for analysis of morphology and symmetry. Full article

The advantages of intraoral model scanning have yielded recent developments. However, few studies have explored the orthodontic clinical use of this technique particularly among young patients. This study aimed to evaluate the reliability, reproducibility and validity of the orthodontic measurements: tooth width, arch length and arch length discrepancy in each digital model obtained by model scanner and intraoral scanner, relative to a plaster model. Arch length measured using two methods: curved arch length (CAL) measured automatically by digital program and sum of sectional liner arch length (SLAL) measured sum of anterior and posterior liner arch lengths. Arch length discrepancy calculated each arch length measurement methods: curved arch length discrepancy (CALD) and sum of sectional liner arch length discrepancy (SLALD). Forty young patients were eligible for the study. A plaster model (P), model-scanned digital model (MSD) and intraoral scanned digital model (ISD) were acquired from each patient. The reliability of the measurements was evaluated using Pearson’s correlation coefficient, while the reproducibility was evaluated using the intraclass correlation coefficient. The validity was assessed by a paired t-test. All measurements measured in P, MSD and ISD exhibited good reliability and reproducibility. Most orthodontic measurements despite of CAL in MSD exhibited high validity. Only the SLAL and SLALD in ISD group differed significantly, despite the good validity of the tooth width, CAL and CALD. The measurements based on the digital program appeared high reliability, reproducibility and accurate than conventional measurement. However, SLAL and SLALD in ISD group appeared shorter because of distortion during intraoral scanning. However, this could be compensated by using digital programed curved arch. Although the validity of SLAL and SLALD in the ISD group differed statistically, the difference is not considered clinically significant. Although MSD and ISD are acceptable for a clinical space analysis, clinicians should be aware of digital model-induced errors. Full article

Active digit-sucking results in (1) reduced vertical growth of the frontal parts of alveolar process which creates an anterior open bite; (2) proclination of the upper incisors as a result of the horizontal force crested by the digit; (3) anterior displacement of the maxilla for the same reason; (4) anterior rotation of the maxilla, resulting in an increased prevalence of posterior crossbite in the deciduous dentition; and (5) proclination or retroclination of the lower incisors which seems to be due to the strength of the tightness of the lower lip and tongue activity during sucking. When the sucking habit stops, the anterior open bite will correct itself spontaneously, due to increased growth of the alveolar processes, provided that the patient is still growing. If the lip activity and the lip/teeth relationship is normal, the upper incisors will upright themselves, and sometimes, due to the anterior displacement of maxilla, become somewhat retroclined. The skeletal effect of the sucking habit will remain. Improper use oi a pacifier can create quite disastrous effects on the occlusion, if, for instance, the child has the shield inside the lower lip or is biting into the shield. Otherwise, the effect of the pacifier is limited to the vertical and the transversal plane. The anterior openbite is normally more obvious and visible earlier in pacifier-suckers than in digit-suckers. As in digit-suckers, the open bite is associated with tongue thrust during swallowing. Also in pacifier-suckers, the open bite will correct itself spontaneously when the habit stops despite the tongue-thrust. Sucking a pacifier is more clearly related to a posterior crossbite in the deciduous dentition than is digit-sucking. When the pacifier is in the child’s mouth, the teat occupies the upper part of the anterior and middle part of the mouth thus forcing the tongue to a lower position. In the upper jaw, the teeth in the canine area lack palatal support from the tongue during the sucking activity of the cheeks. This reduces the arch width and increases the risk of a transversal malrelation between the upper and lower arches. The low tongue position widens the lower jaw in the same area thus enhancing the probability of the development of a posterior cross-bite. Full article