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Objectives: The Functional Clear Aligner (FCA) is a novel orthodontic appliance designed for the treatment of Class II malocclusion with mandibular retrognathia in adolescents. The aim of this study was to investigate the biomechanical characteristics of the masticatory muscles, jawbone, and temporomandibular joint (TMJ) during mandibular advancement using either FCA or Class II elastics combined with clear aligner (Class II elastics) through finite element analysis., Materials and Methods: A 3D finite element model of the 'muscle-jawbone-TMJ-appliance' system was constructed based on CBCT and MRI images of a boy with skeletal Class II malocclusion. Masticatory muscles included masseter, temporal, medial pterygoid, and lateral pterygoid muscles. The TMJ consists of the temporal bone's glenoid fossa, disc, and mandibular condyle. To observe the biomechanical characteristics of the muscles and TMJ during orthodontic appliance wearing and the retention phase, two different protocols were used: Model 1: The mandibular advancement using FCA; Model 2: The mandibular advancement using Class II elastics., Results: The FCA group produced greater and more coordinated masticatory muscle forces compared to the Class II elastics group. Temporal and masseter muscles exhibited the most pronounced variation in muscle strength during mandibular advancement. The FCA group exhibited greater TMJ region stress compared to the Class II elastics group. Interestingly, the stress on the articular discs in both models decreased over time. Tensile stresses were observed in both the condyle and the posterior region of the articular fossa., Conclusion: During skeletal Class II malocclusion treatment, masticatory muscle forces and stress on the TMJ were higher in the FCA group compared to the Class II elastics group. In both models, stress cushioning was provided by the articular disc., (© 2024. The Author(s).)

Background: Class II subdivision is a malocclusion characterized by dental and functional asymmetry that is difficult to manage. Impaired muscle function can result in asymmetrical growth, leading to occlusal instability., Objective(s): The study aimed to assess occlusal force in patients with Class II subdivision malocclusion using Innobyte. Additionally, the discrepancies of force generated at the position of maximum intercuspidation between the left and right sides of the arches were evaluated., Methods: The occlusal force of 66 patients with Class II subdivision malocclusion (group S) was measured and compared with that of 66 patients with Class I (group I) and 66 patients with Class II malocclusion (group II). The S group patients had a Class I molar on the right side and a Class II molar on the left side. ANOVA test, followed by the Games-Howell post hoc test, was performed to compare the mean of the total force among the groups. To assess the difference in force between the right and left arches, one-way ANOVA test followed by Tukey's post hoc comparison was performed. Finally, a boxplot was created to show the trend of occlusal force recorded in the three groups of patients., Results: The occlusal force differed significantly among the groups (p < .001). Post hoc Games-Howell analysis showed significant differences as follows: the total force in group S was 165.24 N greater than in group II and in group I was 218.06 N greater than in group II. The difference (right-left) in total force between the groups was statistically significant (p < .001). Tukey's post hoc test showed following significant correlation: in group S was 53.51 N greater than in group II and 63.12 N greater than in group I., Conclusions: Among the analysed groups, patients with Class II malocclusion exhibited the lowest value of occlusal force. In patients with Class II subdivision malocclusion, force asymmetry, characterised by a higher value on the Class I side and a lower value on the Class II side was observed., (© 2024 The Author(s). Journal of Oral Rehabilitation published by John Wiley & Sons Ltd.)

Purpose: This study aimed to investigate three-dimensional facial soft tissue dimensions, maximum bite force (MBF), and occlusal contact area in patients with DFD. In addition, we analyzed the relationship between MBF and the three-dimensional facial measurements., Methods: Thirty-two patients with skeletal Class III DFD and 20 patients with Class II DFD underwent a soft tissue evaluation using surface laser scanning, as well as MBF and occlusal contact area assessments. The DFD groups were compared with each other and with 25 healthy subjects., Results: Significant morphological differences were found in the transversal, vertical, and anteroposterior dimensions between Class II DFD and Class III DFD. Both DFD groups presented an increased linear distance of chin height, which was strongly related with decreased MBF magnitude. The DFD groups exhibited lower MBF and occlusal contact area, with no significant differences between Class II and Class III DFD., Conclusion: The presence of DFD affected 3D measurements of facial soft tissue, causing variations beyond normal limits, lower MBF, and occlusal contact area in both Class II and Class III DFD patients. The vertical dimension might have influenced the lower MBF magnitude in the studied skeletal deformities.

Objective: This retrospective study aimed to compare the dentoskeletal and soft-tissue changes in Class II malocclusion patients treated with Jasper Jumper and Twin Force Bite Corrector associated with fixed orthodontic appliances., Material and Methods: The sample comprised 60 subjects divided into 3 groups. Patients with Class II malocclusion, mandibular retrusion, slight or no crowding and with no previous orthodontic treatment were eligible. Group 1 comprised 20 patients treated with the Jasper Jumper (JJ), with an initial age of 12.39 years. Group 2 comprised 20 patients treated with the Twin Force (TF), with an initial age of 11.83 years. The control group consisted of 20 untreated Class II subjects with an initial age of 12.13 years. Intergroup pretreatment comparisons were performed with One-way analysis of variance and intergroup treatment changes were compared with the Analysis of Covariance, both followed by Tukey test., Results: The TF group showed greater increase in mandibular length (6.23mm±4.64, P=0.004) than the control group (2.94mm±1.75). The mandibular incisors in the experimental groups presented significantly greater labial inclination and protrusion than the control (Md1.NB; JJ: 4.19°±2.09; TF: 4.46°±6.83; control: 1.13°±2.08, P=0.000/Md1-NB; JJ: 1.95mm±1.45; TF: 1.74mm±1.79; control: 0.31mm±0.81, P=0.000). In addition, the treated groups also showed significantly improvement of the dental relationships (Overjet; JJ: -4.05mm±4.64; TF: -3.80mm±2.12; control: 0.05mm±1.12, P=0.000/Overbite; JJ: -2.52mm±1.46; TF: -2.93mm±2.13; control: -0.63mm±1.35, P=0.000)., Conclusion: The Jasper Jumper and Twin Force associated to fixed appliances were effective in correcting Class II malocclusion with a combination of skeletal and dentoalveolar changes. However, the TF seems to provide more skeletal effects with greater maxillary growth restriction and mandibular length increase when compared to the JJ., (Copyright © 2020 CEO. Published by Elsevier Masson SAS. All rights reserved.)

Objective Maxillary molar distalization with intraoral distalizer appliances is a non-extraction orthodontic treatment used to correct molar relationship in patients with Class II malocclusion presenting maxillary dentoalveolar protrusion and minor skeletal discrepancies. This study compares the changes caused by three distalizers with different force systems. Methodology 71 patients, divided into three groups, were included. The Jones jig group (JJG, n=30; 16 male, 14 female, 13.17 years mean age) was treated with the Jones jig for 0.8 years. The Distal jet group (DJG, n=25; 8 male, 17 female, 12.57 years mean age) was treated with the Distal jet for 1.06 years. The First Class group (FCG, n=16; 6 male, 10 female, 12.84 years mean age) was treated with the First Class for 0.69 years. Intergroup treatment changes were compared using one-way ANOVA, followed by post-hoc Tukey's tests. Results Intergroup comparisons showed significantly greater maxillary incisor protrusion in DJG than in FCG (2.56±2.24 mm vs. 0.74±1.39mm, p=0.015). The maxillary first premolars showed progressive and significantly smaller mesial angulation in JJG, FCG and DJG, respectively (14.65±6.31º, 8.43±3.99º, 0.97±3.16º; p<0.001). They also showed greater mesialization in JJG than FCG (3.76±1.46 mm vs. 2.27±1.47 mm, p=0.010), and greater extrusion in DJG compared to JJG (0.90±0.77 mm vs 0.11±0.60 mm, p=0.004). The maxillary second premolars showed progressive and significantly smaller mesial angulation and mesialization in JJG, FCG and DJG, respectively (12.77±5.78º, 3.20±3.94º, -2.12±3.71º and 3.87±1.34 mm, 2.25±1.40 mm, 1.24±1.26 mm, respectively; p<0.001). DJG showed smaller distal angulation of maxillary first molars (-2.14±5.09º vs. -7.73±4.28º and -6.05±3.76º, for the JJG and FCG, respectively; p<0.001) and greater maxillary second molars extrusion (1.17±1.41 mm vs -0.02±1.16 mm and 0.16±1.40 mm, for the JJG and FCG, respectively; p=0.003). Overjet change was significantly larger in DJG compared to FCG (1.79±1.67 mm vs 0.68±0.84; p=0.046). Treatment time was smaller in FCG (0.69±0.22 years vs 0.81±0.33 years and 1.06±0.42 years, comparing it with the JJG and DJG, respectively; p=0.005). Conclusion The three appliances corrected the Class II molar relationship by dentoalveolar changes. The Distal jet produced smaller molar distal angulation than the Jones jig and First Class. The First Class appliance showed less anchorage loss, greater percentage of distalization and shorter treatment time than the Jones jig and Distal jet.

The aim of this study was to evaluate the differences in sella dimensions and shape between growing patients with Class I, Class II, and Class III skeletal malocclusions, evaluated through morphometric analysis. Seventy-eight subjects aged between 9 and 13 years were selected and assigned to either the Class I, Class II, or Class III groups according to the measured ANB angle (the angle between the Nasion, skeletal A-point and skeletal B-point). Six landmarks were digitised to outline the shape of the sella turcica. Linear measurements of the sella length and depth were also performed. Procrustes superimposition, principal component analysis, and canonical variate analysis were used to evaluate the differences in sella shape between the three groups. A one-way MANOVA and Tukey's or Games-Howell tests were used to evaluate the presence of differences in sella dimensions between the three groups, gender, and age. The canonical variate analysis revealed a statistically significant difference in sella shape between the Class I and the Class II groups, mostly explained by the CV1 axis and related to the posterior clinoidal process and the floor of the sella. No differences were found regarding linear measurements, except between subjects with different age. These differences in sella shape, that are present in the earlier developmental stages, could be used as a predictor of facial growth, but further studies are needed.

Objective: To evaluate whether osseous changes of the temporomandibular joint (TMJ) condyle affect backward rotation of the mandibular ramus in Angle Class II orthodontic patients with idiopathic condylar resorption (ICR). Methods: Twenty Japanese women with Class II malocclusion with ICR (ICR group) and 24 women with Class II malocclusion without ICR (non-ICR group) were examined. Pre-treatment panoramic radiographs were used to measure condylar ratios. Pre-treatment lateral cephalograms were used to evaluate maxillofacial morphology. Results: The ICR group had a significantly smaller condylar ratio, greater backward rotation of the ramus, less labially inclined upper incisors, and a steeper occlusal plane. The increased backward rotation of the ramus in the ICR group was significantly associated with a smaller condylar ratio. Conclusion: Angle Class II patients with ICR had shorter condylar height attributable to osseous changes of the TMJ condyle, and the shorter condylar height may affect subsequent backward rotation of the ramus.

Purpose: The purpose of this study was to examine changes in masseter and medial pterygoid muscles, ramus, condyle and occlusal force after bi-maxillary surgery in class II and III patients., Subjects and Methods: The subjects were 42 patients (84 sides) who underwent sagittal split ramus osteotomy with Le Fort I osteotomy (21 class II cases: mandibular advancement and 21 class III cases: mandibular setback). The cross-sectional measurements of the masseter and medial pterygoid muscles, ramus and condyle were measured in horizontal plane images by computed tomography (CT), before and 1 year after the operation. Occlusal force and contact area were also recorded before and 1 year after the operation., Results: Preoperatively, class II was significantly larger than class III in masseter width (P = 0.0068), masseter area (P < 0.0001) and medial pterygoid length (P < 0.0001). However, class II was significantly smaller than class III in medial pterygoid width (P < 0.0001). After 1 year, class II was significantly smaller than class III in masseter length (P = 0.0017). Class II was still larger than class III in medial pterygoid area after 1 year (P = 0.0343). Class II was significantly larger than class III in condylar angle pre-operatively (P < 0.0001) and after 1 year (P = 0.0006). After 1 year, class II decreased significantly more than class III in condylar thickness (P = 0.0020), condylar width (P < 0.0001) and condylar area (P < 0.0001)., Conclusion: This study suggested that changes in the cross-sectional measurements of masseter and medial pterygoid muscles and the condyle differed between class II and class III patients, although occlusal force did not significantly change 1 year after surgery in both groups., (Copyright © 2018 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Objective: To compare the clinical efficacy of two techniques for fabricating a Bimler device by assessing the patient's surface electromyography (sEMG) activity at rest before treatment and six months after treatment., Methods: Twenty-four patients undergoing orthodontic treatment were enrolled in the study; 12 formed the test group and wore a Bimler device fabricated with a Myoprint impression using neuromuscular orthodontic technique and 12 formed the control group and were treated by traditional orthodontic technique with a wax bite in protrusion. The "rest" sEMG of each patient was recorded prior to treatment and six months after treatment., Results: The neuromuscular-designed Bimler device was more comfortable and provided better treatment results than the traditional Bimler device., Conclusion: This study suggests that the patient group subjected to neuromuscular orthodontic treatment had a treatment outcome with more relaxed masticatory muscles and better function versus the traditional orthodontic treatment.

This study aims to evaluate the prevalence of occlusal traits and to assess parents'/caregivers' satisfaction with child's dental appearance and perception of orthodontic treatment need in 4-5-year-old Estonians. Clinical records and plaster casts of 390 children (190 girls and 200 boys, mean age 4.7 years, range 4 - 5 years) were analyzed. Assessed occlusal traits included deciduous canine and second molar sagittal relationship, overjet, overbite, crowding, midline diastema, crossbite, and scissor bite. Parents'/caregivers' opinions regarding their child's teeth were determined with a questionnaire. The most prevalent occlusal traits were symmetrical sagittal relationship in deciduous canines (78.2%) and molars (75.1%), Class I sagittal relationship in deciduous canines (69.7%) and midline diastema (67.7%). Asymmetrical sagittal canine relationship was registered in 21.8% deciduous canines and in 24.9% second deciduous molars. Parents'/caregivers' perceived orthodontic treatment need was related to Class III sagittal relationship in canines, increased overjet and overbite, negative overbite, and crossbite. Prevalence of most occlusal traits in Estonian children were in line with those reported in neighboring countries. Parents/caregivers were well able to observe occlusal traits that deviated from acceptable occlusion.

Background/objectives: Maxillary tooth distal movement is a treatment option for Class II malocclusion. This prospective clinical study (split-mouth design) was aimed to compare chondroitin sulphate (CS) levels in gingival crevicular fluid (GCF), the rates of tooth movement, and patient pain and discomfort during segmental maxillary posterior tooth distal movement using either 120 or 180 g of retraction force., Materials and Methods: Twenty patients (6 males and 14 females; aged 18.85 ± 4.38 years) with Class II malocclusion were recruited. The force magnitudes were controlled at 120 or 180 g, randomly assigned to either the right or left five-tooth segments. Gingival crevicular fluid samples were collected with Periopaper® strips. Competitive ELISA with monoclonal antibody was used to measure CS levels in GCF. The rates of segmental maxillary posterior tooth distal movement, and the amount of pain and discomfort were evaluated., Results: The median CS levels during the segmental distal movement period were significantly greater than those before the segmental distal movement period (P < 0.05). At each 1-week period during segmental distal movement, the differences between the median CS levels induced by the two different force magnitudes were not significantly different. The rates of segmental distal movement induced by the two different force magnitudes were not significantly different. The mean visual analog scale scores for pain and discomfort with 180 g of retraction force was significantly greater than that with 120 g (P < 0.05)., Conclusions: One hundred and twenty grams of retraction force was sufficient to cause segmental distal movement, as indicated by biochemically assessed bone remodeling activity and a similar rate of tooth movement to that caused by 180 g of retraction force; it also produced less patient pain and discomfort., Trial Registration: The study has been registered as TCTR20170728001.

Objective: The aim of this study was to examine the morphological temporomandibular joint (TMJ) changes that occur after orthodontic treatment in patients with Angle Class II malocclusion., Methods: The post-treatment changes in TMJ morphology were analyzed, based on TMJ cephalometric laminographs in 19 patients with Angle Class II malocclusion and labial inclination of the upper incisors after premolar extraction., Results: The condylar pass angle, articular eminence to the Frankfort horizontal plane angle, and total, upper, and lower heights of the articular fossa increased significantly on both sides after treatment and retention. The anteroposterior width of the articular fossa decreased significantly on both sides after treatment and retention., Discussion: These results suggest that adaptive bone remodeling of the TMJ occurs during the correction of occlusion with labial inclination of the upper incisors by orthodontic treatment after premolar extraction in patients with Angle Class II malocclusion.

The study objective was to determinate variations of stato-dynamical functional markers of postural balance system in the process of malocclusion treatment. Twenty patients aged from 14 to 30 years with class II malocclusion were recruited for this prospective study. All patients underwent electromyography of mm. temporalis and mm. maseter in rest and at maximal jaws pressure. Postural balance was evaluated by stabilometry platform and body's regions relationship was assessed by computer optical topography. Orthodontic interventions included using occlusal splint, dental straps or 'TwinForce' device. There were two diagnostic sessions: before and after one month of orthodontic treatment. The majority of patients after anterior dislocation of mandible demonstrated significant increase in unilateral masticatory muscles activity (р<0.05) which correlated with iliac crest position. According to computerized topography data superior iliac crest position was registered in opposite side with regard to muscle hypertonia. According to stabilometry data forward translation of the mandible resulted in retroversion of total pressure point projection (р<0.05). Asymmetric muscle working in the process of occlusal adjustment may provoke postural imbalance in distal body regions. It dictates postural system condition monitoring during orthodontic treatment.

BACKGROUND Persons with class II division 2 malocclusion are characterized by a very specific dento-skeletal and soft-tissue profile (a profile in which a protruding nose and chin, retruding lips, concave and shortened lower third of the face, and gummy smile are dominant), which is the opposite of the currently modern profiles (convex profile of protruding lips and small chin). The aim of this research was to determine the differences in parameters of harmonies of facial profiles between persons with class II division 2 malocclusions and class I, and to establish the significance of those differences. MATERIAL AND METHODS For this study, 50 patients with class II division 2 malocclusions and 50 patients with class I were selected; profile photos were recorded and a photometric analysis was done: a type of profile according to Schwarz, the shape of a nose, the prominence of chin, biometrical field, the position of lips in relation to the tangent Sn-Pg, S-line (Steiner), E-line (Riketts) and a facial angle according to Arnett. RESULTS The significant differences in profiles of persons with class II division 2 compared to class I were: position and prominence of the chin, the position of the lower and upper lip in relation to the S-line, and smaller value of a facial angle in relation to persons with class I. CONCLUSIONS The differences seen in skeletal profiles were not associated with significant differences in the profiled facial contours of the examined groups. The compensatory role of the fullness of soft tissues of the lips is probably the reason why there were not significant deviations in all the examined parameters.

Background: The aim of this pilot randomized controlled trial (RCT) was to evaluate the sagittal mandibular response induced by rapid maxillary expansion (RME) therapy in mixed dentition patients with class II malocclusion, comparing the effects of bonded RME and banded RME with a matched untreated class II control group., Methods: This RCT was designed in parallel with an allocation ratio of 1:1:1. The sample consisted of 30 children with a mean age of 8.1 ± 0.6 years who were randomly assigned to three groups: group 1 treated with bonded RME, group 2 treated with banded RME, and group 3 the untreated control group. All patients met the following inclusion criteria: early mixed dentition, class II molar relationship, transverse discrepancy ≥ 4 mm, overjet ≥ 5 mm, and prepubertal skeletal maturity stage (CS1-CS2). The expansion screw was activated one quarter of a turn per day (0.25 mm) until overcorrection was reached. For each subject, lateral cephalograms and plaster casts were obtained before treatment (T1) and after 1 year (T2). A randomization list was created for the group assignment, with an allocation ratio of 1:1:1. The observer who performed all the measurements was blinded to group assignment. The study was single-blinded in regard to statistical analysis., Results: RME was effective in the correction of maxillary deficiency. Class II patients treated with both types of RME showed no significant improvement of the anteroposterior relationship of the maxilla and the mandible at both skeletal and occlusal levels. The acrylic splint RME had significant effects on reducing the skeletal vertical dimension and the gonial angle., Conclusions: The orthopedic expansion did not affect the sagittal relationship of class II patients treated in the early mixed dentition when compared with the untreated control group. Additional studies with a larger sample are warranted to elucidate individual variations in dento-skeletal mandibular response to the maxillary expansion protocol in class-II-growing patients., Trial Registration: ClinicalTrials.gov NCT03159962 .

Devices called functional appliances are commonly used in orthodontics for treating maxillary protrusion. These devices mechanically force the mandible forward to apply traction force to the mandibular condyle. This promotes cartilaginous growth in the small mandible. However, no studies have clarified how much traction force is applied to the mandibular condyle. Moreover, it remains unknown as to how anatomical characteristics affect this traction force. Therefore, in this study, we developed a device for measuring the amount of force generated while individual patients wore functional appliances, and we investigated the relationship between forces with structures surrounding the mandibular condyle. We compared traction force values with cone-beam computed tomography image data in eight subjects. The functional appliance resulted in a traction force of 339-1477gf/mm, with a mean value of 196.5gf/mm for the elastic modulus of the mandible. A comparison with cone-beam computed tomography image data suggested that the mandibular traction force was affected by the mandibular condyle and shape of the articular eminence. This method can contribute to discovering efficient treatment techniques more suited to individual patients., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Background: The etiology of Class II division 2 (CII/2) malocclusion focuses on heredity; however lip, cheek, and tongue pressures that are associated with the environmental effect are considered to have an effect. The aim of this study was to evaluate the relation between perioral pressures and the upper incisor inclination in CII/2 malocclusion., Methods: Twenty patients (8 females, 12 males; mean age 10.29 ± 0.90 years) with CII/2 malocclusion were included in the study group, and 15 patients (5 females, 10 males; mean age 10.56 ± 1.06 years) with Class I malocclusion were included. The upper incisors were protruded with a utility arch (0.016 × 0.022 in. blue elgiloy wire). Perioral pressure assessment was made with the Iowa Oral Pressure Instrument. Upper lip pressure, lower lip pressure, vertical lip pressure, left-right buccal pressures, swallowing, and maximum tongue pressures were measured. Repeated measure ANOVA was used to test the intragroup differences. Intergroup comparisons were made using two-way repeated measure ANOVA with Bonferroni correction. Relationships between the variables were analyzed using rank correlation (Spearman's rho). The significance for all statistical tests was predetermined at p < 0.05., Results: A significant change occurred in the upper lip pressure, lower lip pressure, and vertical lip pressure; however, significant difference was not found between the groups. Upper lip pressure increased significantly in both groups. In the CII/2 group, lower lip pressure increased after protrusion and decreased after retention, while vertical lip pressure decreased and then increased significantly. Left buccal pressure changes between the groups were not parallel. Right buccal pressure, swallowing, and maximum tongue pressure changes were not statistically significant. Statistically significant correlation was found between U1-NA (mm) and vertical lip pressure (r -0.467)., Conclusions: In the CII/2 group, upper lip pressure increased only in retention. Lower lip pressure increased and vertical lip pressure decreased after protrusion. Nevertheless, these changes did not remain stable after the retention period. The difference between groups was not statistically significant at the end of retention.

Purpose: The purpose of this study was to examine lip closing force in Class II and III patients before and after orthognathic surgery., Subject and Methods: The subjects were 45 patients (15 Class II women, 15 Class III men and 15 Class III women) diagnosed with jaw deformity who underwent sagittal split ramus osteotomy with Le Fort I osteotomy and 30 controls with normal skeleton and occlusion (15 men, 15 women). Maximum and minimum lip closing forces were measured using Lip De Cum ® before and after surgery, and compared statistically., Results: In the Class II women, maximum and minimum lip closing forces did not change after surgery. However, maximum and minimum lip pressure increased significantly in the Class III men (P = 0.0116, P = 0.0295) and maximum lip closing force increased significantly in the Class III women (P = 0.0082). After 6 months, maximum lip closing force was significantly lower in both Classes II and III women than in the control women (P = 0.0002, P = 0.0045)., Conclusions: This study suggested that maximum postoperative lip pressure did not improve in the Class II women, although maximum lip closing force increased in the Class III men and women after sagittal split ramus osteotomy with Le Fort I osteotomy., (Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Objectives: To investigate the effects of orthodontic non-extraction treatment with or without headgear on the position of and the space available for upper third molars in growing children with class II malocclusions., Materials and Methods: The sample consisted of pre- and post-treatment panoramic radiographs and lateral cephalograms of 294 class II orthodontic patients; 160 were treated with headgear and 134 were treated without headgear. The space available for the upper third molar was measured on the lateral cephalogram as the distance from pterygoid vertical (PTV) to the distal surface of the upper first molar crown (PTV-M1). Angulation, vertical position and tooth development stage of the upper third molars were evaluated on panoramic radiographs. All measurements were evaluated statistically., Results: In both groups PTV-M1 increased, but the increase in PTV-M1 was significantly higher for patients treated without headgear. A linear model for repeated measures revealed that this difference was still significant after correction for age, gender and molar occlusion. Further, there is no evidence that the change in angulation, vertical position and development stage of the upper third molars during orthodontic treatment is influenced by headgear therapy., Conclusion: This study indicates that the use of headgear in growing patients significantly affects the space available for upper third molars. However, orthodontic treatment with headgear does not influence the angulation, vertical position and development stage of upper third molars. It is therefore important to always take into account third molars during treatment planning., (© The Author 2017. Published by Oxford University Press on behalf of the European Orthodontic Society.)

Introduction: The purpose of this study was to clarify the relationships between upper airway factors (nasal resistance, adenoids, tonsils, and tongue posture) and maxillofacial forms in Class II and III children., Methods: Sixty-four subjects (mean age, 9.3 years) with malocclusion were divided into Class II and Class III groups by ANB angles. Nasal resistance was calculated using computational fluid dynamics from cone-beam computed tomography data. Adenoids, tonsils, and tongue posture were evaluated in the cone-beam computed tomography images. The groups were compared using Mann-Whitney U tests and Student t tests. The Spearman rank correlations test assessed the relationships between the upper airway factors and maxillofacial form., Results: Nasal resistance of the Class II group was significantly larger than that of the Class III group (P = 0.005). Nasal resistance of the Class II group was significantly correlated with inferior tongue posture (P <0.001) and negatively correlated with intermolar width (P = 0.028). Tonsil size of the Class III group was significantly correlated with anterior tongue posture (P <0.001) and mandibular incisor anterior position (P = 0.007). Anterior tongue posture of the Class III group was significantly correlated with mandibular protrusion., Conclusions: The relationships of upper airway factors differ between Class II and Class III children., (Copyright © 2017 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Objectives: To examine the influence of negative pressure of the pharyngeal airway on mandibular retraction during inspiration in children with nasal obstruction using the computational fluid dynamics (CFD) method., Setting and Sample Population: Sixty-two children were divided into Classes I, II (mandibular retrusion) and III (mandibular protrusion) malocclusion groups., Material and Methods: Cone-beam computed tomography data were used to reconstruct three-dimensional shapes of the nasal and pharyngeal airways. Airflow pressure was simulated using CFD to calculate nasal resistance and pharyngeal airway pressure during inspiration and expiration., Results: Nasal resistance of the Class II group was significantly higher than that of the other two groups, and oropharyngeal airway inspiration pressure in the Class II (-247.64 Pa) group was larger than that in the Class I (-43.51 Pa) and Class III (-31.81 Pa) groups (P<.001). The oropharyngeal airway inspiration-expiration pressure difference in the Class II (-27.38 Pa) group was larger than that in the Class I (-5.17 Pa) and Class III (0.68 Pa) groups (P=.006)., Conclusion: Large negative inspiratory pharyngeal airway pressure due to nasal obstruction in children with Class II malocclusion may be related to their retrognathia., (© 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Our aim was to investigate the differences in the dynamics of lip force between a group of participants with repaired cleft lips and a group of patients the same age but without clefts. We evaluated 101 children between the ages of 10 to 15 years (unilateral clefts n=35, bilateral clefts n=15, class I malocclusion n=25, and class III malocclusion n=26). Maximum and minimum forces required to close the lips were evaluated with the Lip De Cum ® device (Cosmos Instruments Co Ltd, Tokyo, Japan) for the all groups. We found no significant differences between the maximum and minimum values between boys and girls within the groups, whereas the mean maximum and minimum lip force of the boys was higher than those of the girls in all the groups. This study showed that maximum and minimum lip closing force values were statistically similar in all groups. We conclude, therefore, that patients with bilateral cleft lip have reduced maximum and minimum lip force., (Copyright © 2017 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Introduction: The aim of this study was to investigate muscular function and mandibular kinesiology of patients undergoing orthodontic-surgical treatment by electromyography and kinesiography. Electromyographic evaluation is essential to estimate masticatory forces in patients undergoing combined surgical-orthodontic treatment., Materials and Methods: 60 patients referred for orthodontic surgical treatment were included in the study, 43 patients presented a class III while 17 presented a class II. The patients underwent electromyographic and kinesiographic examinations during all the therapeutic orthodontic-surgical phases., Results: The relationship between fundamental electromyographic values and age, weight, asymmetry and activation was weak. A strong and positive relationship was observed between the relaxation percentage after TENS (transcutaneous electrical neuromuscular stimulation), the steepness of the post-surgery rehabilitation curve, the initial POC (percentage overlapping coefficient), and for the values in microvolts of the right and left temporal and masseters at the beginning of treatment., Conclusions: Patients with dentofacial deformities corrected by surgical treatment, have a significant positive treatment outcome in respect of masticatory activity and performance electromyographic evaluation on, before, during and follow up period of the analized patients permit to underline that this examination can predict long term stability.

Introduction: Polysomnographic recordings of children with an apparent life-threatening event (ALTE) have often displayed signs of partial or complete obstruction during sleep. Various studies have focused on facial dysmorphia in infants with ALTE and tried to establish a correlation between ALTE and obstructive sleep apnoea. Our study evaluates the phenotypic characteristics and the presence of sleep disorders in pre-school children who had at least one ALTE in the first year of life., Materials and Methods: We analyzed a group of pre-school children (mean age 5.21 ± 0.90 years) who were referred for an ALTE between 2008 and 2010. Children with no history of ALTEs were recruited as a control group. A detailed personal and family history was obtained for all the participants. Moreover, all the children underwent a general clinical examination and an ear, nose, and throat and orthodontic assessment. A clinical score was calculated according to the previously validated Sleep Clinical Record (SCR)., Results: In the ALTE group (n = 107), snoring (25.2% vs. 6.1%), apnoeas (19.6% vs. 4.3%), restless sleep (31.7% vs. 6.1%), and habitual mouth breathing (35.5% vs. 12.2%, P < 0.05) were significantly more common (P < 0.05) than in the control group (n = 115). The ALTE group also displayed a higher frequency of Angle class II (27.1% vs. 15.7%, P < 0.05), narrow palate (72.9% vs. 51.3%, P < 0.05), and Friedman palate position (grades III-IV) (31.7% vs. 16.6%, P < 0.05) than the control group. Moreover, 38/107 (35.5%) children in the ALTE group had a positive SCR score compared with 14/115 controls (12.2%) (P < 0.05)., Conclusions: Pre-school age children with previous ALTE had a higher frequency of sleep disordered breathing and malocclusion phenotypes. The occurrence of ALTEs may be predictive of the development of sleep disordered breathing and highlight the importance of a long-term follow-up. Pediatr Pulmonol. 2016;51:1403-1408. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Objective: To evaluate mandibular kinematics in class I adults following class II therapy with removable functional appliances (RFAs) during the growth period in comparison with orthodontically untreated class I and II individuals., Methods: Condylar (CRoM) and incisal range of motion (InRoM), velocity during opening and closing, and the mandibular rotation angle were recorded using an ultrasound-based jaw-tracking system in 36 test patients (mean age = 28.03 ± 6.58 years)., Results: Significant group effects were found for CRoM towards the posterior in the right joint (p = 0.002) and InRoM towards the anterior (p = 0.043). The post hoc Tukey test indicates a significantly longer CRoM (posterior) for the right condyle in class II (p = 0.003) and RFA individuals (p = 0.023)., Discussion: The kinematic data imply greater dentoalveolar effects due to RFA therapy than adaptive remodeling of the temporomandibular joint. The class I relationship in the RFA group following treatment indicates stable long-term outcomes.

Objectives: To evaluate changes in occlusal characteristics in the primary dentition that occur after introducing a thin-neck pacifier (TNP) to children with previously diagnosed pacifier-associated anterior open bite (AOB) and increased overjet., Setting and Sample Population: Department of Preventive and Pediatric Dentistry, Jena University Hospital, Germany. Subjects were 86 children (mean age 20.3 months) with a pacifier-associated open bite or overjet ≥2 mm., Material & Methods: Randomized controlled trial. Subjects were randomly assigned: group I (n = 28), intervention group using a TNP; group II (n = 30), control group, using a conventional or physiological pacifier; and group III (n = 28), intervention group, Gold standard, weaned off pacifier. Participants were re-examined after 3, 6, 9 and 12 months by an operator, blinded for the treatment., Results: After 12 months data for 63 children (mean age 33.1 months) were analyzed (I: n = 24; II: n = 22; III: n = 17). There was a significant difference between the groups regarding mean overjet (group I: 2.7 ± 0.5 mm, group II: 3.2 ± 0.7 mm, group III: 2.4 ± 0.5 mm, Kruskal-Wallis, p = 0.002) and AOB (group I: -1.2 ± 0.3 mm, group II: -2.2 ± 0.3 mm, group III: -0.8 ± 0.8 mm, Kruskal-Wallis, p < 0.001). The differences between group I and II regarding increased overjet (3.1 ± 0.2 mm vs. 3.6 ± 0.3 mm, Mann-Whitney, p < 0.001) and extent of AOB (-1.2 ± 0.3 mm vs. -2.2 ± 0.3 mm, Mann-Whitney, p < 0.001) were statistically significant., Conclusion: Use of TNP resulted in better clinical measurements for in overjet and overbite compared with the continuing use of conventional or physiological pacifiers., (© 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: The aim of this study was to evaluate the possible influence of a malocclusion pattern on a patient's posture., Methods: Patients affected by symmetric malocclusion or malocclusion with mild to moderate non-syndromic craniofacial asymmetry were submitted to a clinical and X-ray evaluation. Subjects with symmetric skeletal class I were used as the control group. Evaluation of differences in postural pattern was performed using rasterstereography., Results: Statistical analysis (t-test) was performed on 61 patients divided in homogeneous subgroups. The results show a pelvic torsion angle of 1.08° + 3.00° (P = 0.0023) (normal value (NV) = 0.0-1.9°) in subjects presenting skeletal class II z asymmetry (control group: 1.17° ± 1.25°, not significant (NS))., Conclusions: The present study shows evidence of a relationship between malocclusion and spinal posture. A better understanding of the relationship between malocclusion and posture may help in planning a multidisciplinary approach that could involve other specialists.

Introduction: The aim of this study was to evaluate the effect of malocclusion severity on oral health-related quality of life and food intake ability in adult patients, controlling for sex, age, and the type of dental clinic visited., Methods: The sample consisted of 472 Korean patients (156 male, 316 female) with a mean age of 21.1 (SD, 8.6) years in a dental hospital and a private clinic. The correlations between the Korean version of the Oral Health Impact Profile-14 (OHIP-14K), subjective food intake ability (FIA) for 5 key foods, and Index of Orthodontic Treatment Need-Dental Health Component (IOTN-DHC) were investigated., Results: The mean IOTN-DHC and OHIP-14K scores were significantly higher for the dental hospital patients than for the private clinic patients (IOTN-DHC, P <0.001; OHIP-14K, P <0.05). Malocclusion severity was significantly higher in male than in female subjects (P <0.001). Older patients perceived their oral health-related quality of life more negatively than did the teens (P <0.001). As the severity of the malocclusion increased, oral health-related quality of life and masticatory function worsened (OHIP-14K, P <0.001; FIA, P <0.05)., Conclusions: As the severity of the malocclusion and the age of the patients increased, oral health-related quality of life and masticatory function relatively deteriorated. This finding provides evidence that severe malocclusions are associated with lower quality of life and less masticatory efficiency in older patients., (Copyright © 2016 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Purpose: To analyze the speech articulatory characteristics of individuals with dentofacial deformities (DFD) and assess differences compared to individuals with dentofacial balance., Methods: Sixty individuals participated, being 30 presenting DFD (19 with class III and 11 class II skeletal malocclusion, 18 women and 12 men, age group 18-40 years) and 30 individuals from a control group matched for gender and age. The assessment of the diadochokinesis (DDK) was evaluated using the emissions /pa/, /ta/, /ka/, /pataka/, and /i/., Results: The individuals with DFD produced fewer emissions per second: at syllable "ka" and sequence "pataka" for the total of individuals; syllable "pa" and sequence "pataka" for women, individuals with class II and class III malocclusion. The parameters related to the irregularity of the cycles were higher for the group with DFD than for the control, as well as emission of the syllable "pa" for the total of individuals, group of class III malocclusion and women, during production of the syllables "ta" and "ka" for all individuals and group of class III and during emission of the vowel "ï" for women., Conclusions: Differences regarding speed and stability of oral and laryngeal DDK were found among individuals with DFD compared with the control group.

Treatment outcomes of Angle Class II subdivision malocclusions may be compromised because of the uncertainty of the aetiology. Previous studies have reported controversial ideas about the origins, but the existence of a primary contributor still remains unknown. Functional factors have been mentioned as a probable cause, but until now, there have been no supporting data. This study was a cross-sectional investigation of the characteristics of Angle Class II subdivision malocclusion, including dental, skeletal and functional factors, by comparison of the subdivision group and the normal occlusion group. The evaluations of dental and skeletal asymmetries of both groups were carried out by cone-beam computed tomography (CBCT) and analysis of dental casts. The functional deviations were evaluated by cast mounting and measuring. In the subdivision group, the asymmetric position of the glenoid fossa was found to be the most significant skeletal asymmetry. No dentoalveolar asymmetry was found in this group. The most important finding was that, in subdivision malocclusions, functional deviation resulting in pseudoasymmetry occurred in 32.86% of the study participants. This deviation is probably related to the disharmonious arch width between maxillary and mandibular dental arches in the premolar section. The origin of Angle Class II subdivision malocclusion is multifactorial, with dental, skeletal and functional factors included. Functional deviation occurs, probably due to dental arch width disharmony. Asymmetric position of the glenoid fossa may account for most of the skeletal asymmetry., (© 2015 John Wiley & Sons Ltd.)

Introduction: The purposes of this study were to examine and compare the craniofacial growth in girls with Class I or Class II occlusion from the ages of 9 to 18., Methods: Twenty-five Class I (ANB, 1°-4°) and 21 Class II (ANB, >4°) untreated Caucasian girls were selected from the Burlington Growth Centre in Toronto, Ontario, Canada. Cephalograms of each subject at ages 9, 14, and 18 years were traced, and 29 parameters were measured. The growth changes in each parameter from ages 9 to 14, 14 to 18, and 9 to 18 were calculated, and comparisons of each parameter were made between the 2 groups., Results: From ages 9 to 14, the Class I and Class II groups had similar skeletal growth patterns (increases of SNA and SNB angles, decreases of ANB, MP-SN, and gonial angles). Dentally, the Class II group showed less maxillary incisal proclination and more overbite than did the Class I group. From ages 14 to 18, the 2 groups also showed similar growth patterns, with little sagittal but continued vertical growth, and the MP-SN angle continued to decrease. From ages 9 to 18 (combined periods of 9-14 and 14-18), the 2 groups showed similar skeletal growth, with the exception of a slightly higher ANS-ME/N-Me in the Class I group. Dental changes were similar in the 2 groups, except that overbite increased slightly more in the Class II group., Conclusions: Overall, the craniofacial growth patterns of Class I and Class II girls were similar. With growth, the face became more flattened with a decrease of the ANB angle, and the mandible demonstrated forward rotation with decreases of the MP-SN and gonial angles, and an increase of PFH:AFH., (Copyright © 2015 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Aim: The aim of this study is to assess the response and changes on pharyngeal airway passage (PAP) to class II Andresen appliance in class II growing patients with obstructive sleep apnea syndrome (OSAS)., Methods: The sample consisted of forty patients with a class II malocclusion in the age range of 9 to 14 years with mandibular retrusion and OSAS and ten control group subjects. A CBCT was taken before treatment (T0) and a second one after a follow-up period of approximately 16 months (T1). The dimensions of PAP were determined according to the method described by Jena et al. with Mimics program. The following parameters were considered: DOP, DPH, MP-H, PAS, PNS-U, SNA, SNB, ANB. The statistical analysis was carried out with t test., Results: The change in ANB, SNB, MP-H, PNS-U, PAS was significantly more in the patients undergoing treatment as compared to the control group. The improvement of DOP and DPH among the treatment group subjects was significantly more compared to the control group subjects., Conclusions: Class II correction by functional appliances during childhood might help to eliminate the adaptive changes in the upper airway and predisposing factors to OSAS, thus decreasing the risk of OSAS development in adulthood.

Background: The purpose of this study was to predict the annual growth rate of the mandible and total anterior facial height using IGF-1 levels together with cervical stage, skeletal classification, and gender., Methods: Twenty-five orthodontic patients (12 females and 13 males) had their cervical stages, blood-spot IGF-1 levels, and cephalometric parameters measured at 1-year intervals. The number of years each patient was followed up varied between 1 and 5 years resulting in 43 12-month intervals collected from 77 observations. Descriptive, bivariate, and regression analyses were used to analyze this data., Results: The linear regression model for predicting the annual mandibular growth rate was significant at p < 0.01 with an R-square value of 0.52. We found that the average IGF-1 level for the interval, the change in IGF-1 level, and the presence of a skeletal class III pattern were statistically significant predictors of mandibular growth. The regression model for predicting the annual change in anterior facial height was significant at p < 0.01 with an R-square value of 0.42. We found that the change in IGF-1 level was the only statistically significant predictor of this outcome., Conclusions: The proposed method which combines IGF-1 levels with information that is readily available to clinicians can be used to predict the timing and intensity of the growth spurt. These factors together explain more of the observed individual variation in growth rate than any of the factors used in isolation.

Background/aim: The muscles of the orofacial region have great influence on the development of dentition and occlusion formation. It is known that improper function of these muscles is one of the major etiological factors in malocclusion. A correlation between function disorders of orofacial muscle and occlusion disorders has been confirmed, as well as a correlation between the bioelectric activity of the masticatory muscles, recorded by electromyography, and bite force upon maximal voluntary contraction of these muscles. The aim of the study was to analyze the bioelectriacal activity of temporal and masseter muscles., Methods: The sample consisted of 100 subjects of both sexes, divided into the control group (n = 30) with neutral and complete dental arches, and the study group (n = 70) of patients with distal occlusion. Electromyographic measurement of bioelectric potentials in all the subjects was conducted for the examined muscles in the physiologic rest position, central mandible occlusion, and during maximal voluntary contraction of muscles and saliva swallowing, in Angle Class I and II/2 occlusal relationships, prior to treatment, after one year of the orthodontic treatment and after the treatment with an activator., Results: Comparing the values of the bioelectrical activity in the control and the study group before the treatment, a decreased muscle activity was established in all the three positions in the study group. After the first year of orthodontic treatment the results showed an elevation in the bioelectrical activity in both muscles. After treatment with an activator, the bioelectrical activity in both muscles in the study group was higher than before the treatment, as it is confirmed by a positive highly significant coefficient of correlation., Conclusion: In all the three measured positions of the mandible with Angle Class II/2 malocclusion, bioelectrical activity was lowest at baseline and increased during the first year of treatment, and at the end of the treatment it partially reduced close to the approximate values in normal occlusion. Research on electromyographic activity of masticatory muscles is useful in everyday clinical practice, especially in present distinctive skeletal discrepancy before, during and after orthodontic treatment, if on the bases of the results we can evaluate the treatment, but also determine the start and duration of the retention period and retention device type.

Objective: To determine class and sex differences in mandibular growth and modeling., Materials and Methods: A mixed-longitudinal sample of 130 untreated French-Canadian adolescents, 77 (45 boys and 32 girls) with Class I (normal or abnormal) occlusion and 53 (26 boys and 27 girls) with Class II division 1 malocclusion, was used. Based on eight landmarks, eight traditional measurements were used to compare the anteroposterior position of the maxilla and mandible, relationship between the jaws, and mandibular size. Mandibular superimpositions were used to compare the horizontal and vertical changes of condylion, gonion, and menton., Results: While there were no differences in maxillary position based on the SNA angle, Class IIs had more retrognathic mandibles than did Class Is. Total mandibular length was greater in Class Is than in Class IIs at 15 years of age. Superior and total growth and modeling changes at condylion and gonion, respectively, were greater for Class Is than Class IIs. Boys were more prognathic than girls; they had larger mandibles and exhibited greater size increases and growth changes than girls did., Conclusions: There are both class and sex differences in mandibular growth and modeling.

Unlabelled: In adults, sleep bruxism (SB) may be related to reports of pain or fatigue in the muscles of mastication, resulting from multiple muscle contractions that occur during the night. In children, little is known about the consequences of this parafunction., Purpose: The objective was to compare the electromyographic activity (EMG) of the masseter and anterior portion of the temporalis muscles in children with and without SB; acquisitions were made at rest (RE) and in maximal intercuspal (MI) positions of the mandible., Methods: Twenty children with signs and symptoms of SB (mean age 7.20 years ± 0.52) and 20 controls without signs or symptoms of SB (mean age 7.40 years ± 0.50) were selected. The controls were matched to the type of occlusal morphology evaluated according to Björk et al. (Acta Odontol Scand 22:27-40, 1964). Muscle activity was measured with the mandible at RE, MI and maximal clenching with cotton roll (MC), on the left and right sides. Data from the RE and MI (mV) were normalized by calculating them as % MC. The results were analyzed by descriptive statistics, Shapiro-Wilk test, Wilcoxon and Mann-Whitney tests., Results: The subjects' age did not differ significantly between groups. EMG of temporalis muscle at RE differed between the right and left sides in both groups. There was no significant difference in EMG of masseter and temporalis muscles between groups., Conclusion: Children with SB showed no significant difference in EMG of masticatory muscles at RE and in MI positions of the mandible when compared with the control group.

The purpose of this cross-sectional research was to explore the relationship of the mandibular dental and basal bone archforms between severe Skeletal Class II (SC2) and Skeletal Class III (SC3) malocclusions. We also compared intercanine and intermolar widths in these two malocclusion types. Thirty-three virtual pretreatment mandibular models (Skeletal Class III group) and Thirty-five Skeletal Class II group pretreatment models were created with a laser scanning system. FA (the midpoint of the facial axis of the clinical crown)and WALA points (the most prominent point on the soft-tissue ridge)were employed to produce dental and basal bone archforms, respectively. Gained scatter diagrams of the samples were processed by nonlinear regression analysis via SPSS 17.0. The mandibular dental and basal bone intercanine and intermolar widths were significantly greater in the Skeletal Class III group compared to the Skeletal Class II group. In both groups, a moderate correlation existed between dental and basal bone arch widths in the canine region, and a high correlation existed between dental and basal bone arch widths in the molar region. The coefficient of correlation of the Skeletal Class III group was greater than the Skeletal Class II group. Fourth degree, even order power functions were used as best-fit functions to fit the scatter plots. The radius of curvature was larger in Skeletal Class III malocclusions compared to Skeletal Class II malocclusions (rWALA3>rWALA2>rFA3>rFA2). In conclusion, mandibular dental and basal intercanine and intermolar widths were significantly different between the two groups. Compared with Skeletal Class II subjects, the mandibular archform was more flat for Skeletal Class III subjects.

Objective: A study was designed to determine changes in the amplitude of the EMG muscular activity of the Masseter and Temporalis muscles at clench in children with a Class II, division 1 malocclusion treated with the pre-orthodontic Trainer functional appliance, for 12 months., Study Design: 36 Class II, division 1 malocclusion patients (mean age 7.6 ± 1.3 years) composed the treated group and wore the functional appliance; 22 children with a similar age and malocclusion composed the untreated controls; and, 20 children with no dental malocclusion participated as normal controls. Electromyographic (EMG) muscular activity of the Temporalis and Masseter muscles were recorded before and after treatment., Results: Subjects in the treated group reported a bilateral significant increase in the muscular electrical activity in the both tested muscles (p < 0.001). After treatment, they recorded values similar to those measured in normal controls, whereas the untreated controls remained on lower values., Conclusion: These results confirm that treatment with the pre-orthodontic Trainer functional appliance significantly increases the EMG muscular activity in the Temporalis and Masseter muscles at clench in patients with Class II, division 1 malocclusion.

Introduction: Class II subdivision malocclusions with their asymmetric occlusal relationships often pose treatment difficulties. The aim of this study was to evaluate the longitudinal changes of dental arch asymmetry in untreated subjects with Class II subdivision malocclusion., Methods: From 706 files from the University of Michigan Growth Study, longitudinal records of 17 untreated subjects with Class II subdivision malocclusion were included this study. Dental arch changes at 3 consecutive longitudinal intervals, defined by the cervical vertebral maturation method, were analyzed on digital dental models. The average ages of the subjects were 12.4, 15.1, and 19.1 years at the 3 time periods, respectively. Maxillary and mandibular reference lines were constructed and used for the intra-arch asymmetry measurements. The Friedman test and analysis of variance with repeated measures were used to determine dental arch asymmetries at the P <0.05 level., Results: All subjects were found to have a type 1 Class II subdivision malocclusion characterized by distal positioning of the mandibular first molar on the Class II side. No statistically significant intra-arch asymmetry changes were found for the maxillary and mandibular dental arches in any time period. Between the baseline and the final follow-up, the data indicated decreases in maxillary and mandibular intercanine arch widths and arch lengths symmetrically., Conclusions: The results of this study indicate that the dental arch asymmetry in patients with Class II subdivision malocclusions did not improve or worsen with growth., (Copyright © 2014 American Association of Orthodontists. Published by Mosby, Inc. All rights reserved.)

Aim: To examine the long-term effects induced by treatment with the function regulator (FR-2) appliance 7 years post-treatment compared with untreated class II subjects., Subjects and Methods: The FR-2 sample was collected prospectively and comprised 17 subjects (10 boys and 7 girls, mean age 10.8 years) who were treated with the FR-2 appliance for 1.7 years and re-evaluated 7.1 years after treatment. The step-by-step mandibular advancement was performed gradually (increments up to 3-4 mm), until a 'super class I' molar relationship was obtained. The control group consisted of 17 class II subjects (9 boys and 8 girls, mean age 11.3 years) with class II malocclusion, excessive overjet, and class II molar relationship, matched to the treated group as to ages at all times, gender distribution, and stages of skeletal maturity (evaluated by the cervical vertebral maturation method). The lateral cephalograms were analysed at T1 (initial), T2 (final), and T3 (7.1 years post-treatment). The compatibility between the groups and the comparisons of their changes at T1-T2, T2-T3, and T1-T3 intervals were examined by independent sample t-tests (P < 0.05)., Results: FR-2 treatment provided a significant improvement in the maxillomandibular relationship due to an increase in mandibular length compared with controls, which remained stable over time. Also overjet, overbite, and molar relationship corrections demonstrated stability. Among dentoalveolar changes, only the increased mesial movement of the mandibular molars in the FR-2 group demonstrated stability., Conclusions: Correction of class II malocclusion remained stable 7 years after FR-2 treatment mainly due to the stability of the skeletal changes.

Objective: The aim of this study was to evaluate the efficiency of molar distalization depending on age and second-molar eruption using the Beneslider., Materials and Methods: Treatment of 51 patients (mean age 17.8 ± 9.6 years) was investigated retrospectively by means of pre- and posttreatment cephalograms. Patients were divided into three groups: 14 children with unerupted upper second molars (group 1), 23 adolescents with second molar in place (group 2), and 14 adults (group 3). The distalization forces applied were 2.4 N in group 1 and 5.0 N in groups 2 and 3. Treatment changes were evaluated and examined statistically for significant differences., Results: In all patients a Class I molar relationship was achieved. All mini-implants remained stable during treatment. Mean distalization distance as measured by the displacement of the center of resistance was 3.6 ± 1.9 mm (range 1.2-8.5 mm depending on treatment needs). Since no significant tipping was detected, the type of movement can be described as bodily movement. Mean overall distalization speed was 0.6 ± 0.4 mm per month. There were no statistical differences between the groups., Conclusion: We found the Beneslider to be an effective appliance that enables bodily distalization in adequate treatment time. The higher resistance due to erupted second molars can be compensated by the use of higher forces without significantly reducing distalization speed.

Aim: The aim of this cephalometric study was to evaluate the influence of the sagittal skeletal pattern on the 'Y-axis of growth' measurement in patients with different malocclusions., Materials and Methods: Lateral head films from 59 patients (mean age 16y 7m, ranging from 11 to 25 years) were selected after a subjective analysis of 1630 cases. Sample was grouped as follows: Group 1 - class I facial pattern; group 2 - class II facial pattern; and Group 3 - class III facial pattern. Two angular measurements, SNGoGn and SNGn, were taken in order to determine skeletal vertical facial pattern. A logistic regression with errors distributed according to a binomial distribution was used to test the influence of the sagittal relationship (Class I, II, III facial patterns) on vertical diagnostic measurement congruence (SNGoGn and SNGn)., Results: RESULTS show that the probability of congruence between the patterns SNGn and SNGoGn was relatively high (70%) for group 1, but for groups II (46%) and III (37%) this congruence was relatively low., Conclusion: The use of SNGn appears to be inappropriate to determine the vertical facial skeletal pattern of patients, due to Gn point shifting throughout sagittal discrepancies. Clinical Significance: Facial pattern determined by SNGn must be considered carefully, especially when severe sagittal discrepancies are present.

The aim of the present work was to determine the duration of the adolescent peak growth spurt using cervical vertebral maturation analysis in class I and II malocclusion subjects. The study was conducted on a sample which consisted of 154 lateral cephalograms of children and adolescents aged 9-15 years (84 females and 70 males). The evaluation of skeletal maturation stage was performed using a visual morphological analysis of CS3 and CS4 cervical vertebrae. The sagittal skeletal relation was evaluated according to Steiner analysis. Descriptive statistics were used to summarize chronological age in each malocclusion group and for each CS3 and CS4 skeletal maturation stage. Due to a lack of normal distribution, comparisons of CS3 and CS4 age intervals on class I and II subjects were compared using the Mann-Whitney U test for independent samples. The results show that the mean duration of the adolescent peak growth spurt was 10 months between CS3 and CS4 stages in class I malocclusion subjects, whereas in class II malocclusion patients the duration was 6 months. This difference of 4 months was statistically significant (p<0.001). Finally, a clinically significant difference of 4 months in the duration of the adolescent peak growth spurt for class I and II malocclusion subjects was identified.

In the era of fixed appliances, some orthodontic practitioners seem to forget about functional therapy. Functional appliances are the only capable of orthopedically changes during the growth spurt. Activators of all types, classic or opened, are elected appliances in growing subjects with class II/1 anomalies. The appropriate case selection, along with patient compliance, lead to improved facial aesthetic and dental occlusion, at affordable prices. With this case presentation, we want to show our protocol in the management of these cases.

The objective of this study was to describe the oral phase of swallowing in individuals with dental malocclusion and to generate data that would contribute to the rehabilitation of those patients. The study was based on the evaluation of the swallowing system through videofluoroscopy on thirty-four children of both genders, aged eight to twelve years old who present with Angle Class II and III dental malocclusions. Thirteen children of similar age and gender presenting normal dental occlusion formed the control group. The results indicated that the oral phase of swallowing is different between individuals with normal occlusion and malocclusion. Dental occlusion types Angle Class II and III did not present a swallowing pattern, independently of the amount of liquid ingested. The swallowing appeared effective in the oral phase of individuals with dental malocclusion, even though adaptations were identified. The outcome, in the absence of a single pattern and the efficiency of the adapted swallowing demonstrates, first a need for additional research investigating orofacial myofunctional treatment for patients with malocclusion and second how such analyses should focus on contributing positively to the rehabilitation of these patients.

Objective: To investigate the occlusal configurations of the hyperdivergent skeletal Class II malocclusion and their alterations during the camouflaging treatment in an attempt to identify occlusal changes that might be related to mandibular counterclockwise rotation., Materials and Methods: Cephalograms of 126 subjects with hyperdivergent skeletal Class II malocclusion and 126 subjects with a clinically normal skeletal pattern were chosen. Several measurements were calculated and compared between the groups. To examine the effects of treatment, two groups were established according to mandibular rotation: counterclockwise rotation (CCR) and the opposite clockwise rotation (CR). After 40 subjects were excluded, the other 86 Class II subjects were assigned to CCR (n = 22) and CR (n = 64). Their pretreatment (T1), posttreatment (T2), and postretention (T3) cephalograms were obtained. Measurement changes (T3-T1) were analyzed in each group and compared between groups., Results: Compared with the normal skeletal pattern, the cant of the occlusal plane (OP) of the study subjects was significantly steeper and the vertical heights of the incisors were significantly larger for the malocclusion. Compared with the changes in CR, there was a prominent reduction of the OP canting with remarkable intrusion of the maxillary incisor in CCR., Conclusion: Increased OP canting with overerupted incisors is evident in the hyperdivergent skeletal Class II malocclusion. During the camouflaging treatment, reduction of OP canting could occur. It was accompanied by mandibular counterclockwise rotation and intrusion of the maxillary incisor.

Objective: To clarify, by three-dimensional (3D) facial scans, if 4- to 6-year-old children with intraoral sagittal discrepancies and open-bite occlusion show differences in facial morphology when compared to children without anomalies., Materials and Methods: Scans of 290 children presenting with occlusal abnormalities were compared to 1772 face scans of age-matched individuals photographed with a faceSCAN II® 3D data acquisition system. From these, three study groups were formed comprising 188 children with distal occlusion/increased overjet (Class II), 37 with mesial occlusion/inverse overjet (Class III), and 65 with open-bite occlusion. These groups were evaluated by age and gender for each group compared to the control individuals., Results: The Class II group showed statistically significant reduced dimensions of head width, upper face width, and midface length. In addition, the mean values for mouth width and lip thickness were higher, and their upper lips were located more anteriorly than in the control group. The Class III group exhibited more markedly retruded upper lips. The facial profile of female 5-year-old Class III patients was significantly more concave. Patients in the open-bite group showed reduced upper lip length, with differences only being statistically significant in male 4-year-olds., Conclusion: Dental Class II with increased overjet and dental Class III with decreased overjet influence soft tissue morphology and are represented on 3D facial scans.

Introduction: Myofascial pain dysfunction syndrome (MPDS) is a disorder which is characterized by facial pain and limited mandibular function because of the complex nature of this disease. Malocclusion was never evaluated in MPDS patients to know its role. Electromyographic silent period durations of masseter were used for objective assessment of MPDS patients., Aim: To evaluation of role of malocclusion in MPDS patients and also to study the EMG masseteric silent period pattern in MPDS patients in different malocclusions., Materials and Methods: Two groups, groups I and II of 75 subjects each, were included in this study. Groups I and II constituted the normal subjects and MPDS patients respectively. All these subjects in both the groups were again subdivided based on Angle's class I, II and III malocclusion. Electromyographic (EMG) silent period of masseteric muscle on both sides was measured for all the subjects in both the groups to know whether it differs according to the type of malocclusion., Results: The silent period was more in group II (MPDS patients). There was no signifcant difference in the silent periods in Angle's class I, II and III malocclusion in group I, whereas in group II, there was a signifcant difference in the silent period in Angle's class II compared to Angle's class I and III. There was no signifcant difference between males and females., Conclusion: MPDS patients are more in Angle's class I malocclusion. Silent period is more in Angle's class II malocclusion of MPDS group. CLINICAL SIGNIFCANCE: The EMG masseter silent period duration can be advantageously utilized as an adjunct to clinical examination for diagnosis of myofascial pain dysfunction syndrome. It is enough if one side masseter muscle is measured for silent period duration.