Upper airways changes associated with orthodontic molar distalization by Pendulum appliance in adolescent patients: a multicenter retrospective cephalometric study.

OBJECTIVES: The purpose of this multicenter retrospective study was to perform a two-dimensional analysis of upper airway changes in adolescent patients following molar distalization with the Pendulum appliance. MATERIALS AND METHODS: The study involved the cephalometric analysis of 88 patients, retrospectively categorized into two groups: skeletal Class II with a dental Class II molar relationship (36 patients, mean age 12.6 ± 1.1 years) and skeletal Class I with a dental Class II molar relationship (54 patients, mean age 12.3 ± 1.2 years). Changes were observed using lateral radiographs before (T0) and after Pendulum appliance removal (T1); treatment time averaged 7 months. Upper airways were subsequently analyzed by tracing lateral radiographs. The Shapiro-Wilk test showed a normal distribution of the data, therefore parametric tests were used for statistical analysis. Intragroup changes between T0 and T1 were evaluated using paired t-tests, and intergroup differences were assessed using independent student t-tests; statistical significance was set at 0.05. RESULTS: Statistically significant differences were observed in the skeletal measurements that characterized both groups, particularly in ANB and Wits appraisal, at T0 (P < 0.001). After molar distalization, Class I and Class II groups reported no statistically significant differences with changes almost equal to zero between timepoints (P > 0.05). Additionally, intergroup comparisons of airway changes at T1 did not show statistically significant differences (P > 0.05). CONCLUSIONS: The Pendulum appliance does not significantly change the upper airway dimensions in Class I and Class II malocclusion patients, thereby minimizing potential respiratory risks.

Digital-assisted diagnosis and orthodontic management of an impacted mandibular lateral incisor: a case report.

BACKGROUND: The impaction of mandibular lateral incisors presents significant aesthetic and functional challenges in orthodontics, including Bolton ratio discrepancies and anterior occlusal anomalies. The increasing preference for nonextraction treatment further complicates space management within the dental arch. However, the advent of digital-assisted orthodontic technologies, particularly advanced digital simulations, has revolutionized the precision and effectiveness of diagnosis and treatment planning. These technologies enable clinicians to strategically leverage natural jaw development and create the necessary space for the alignment of impacted teeth without resorting to extraction. CASE PRESENTATION: This case report details the treatment of a 12-year-old male with an impacted mandibular lateral incisor, which resulted in both aesthetic concerns and functional impairments, alongside Class II malocclusion. By employing a digital-assisted diagnostic approach, including comprehensive digital simulations, we meticulously evaluated the feasibility of a nonextraction treatment plan. The strategy centred on harnessing the patient's mandibular growth potential to expand the available space naturally. The treatment involved surgical exposure of the impacted tooth, followed by precise orthodontic traction guided by continuous digital monitoring. The integration of digital tools throughout the treatment process was crucial in achieving successful eruption and alignment of the impacted tooth, thus restoring optimal aesthetics and function without the need for extraction. CONCLUSION: This case highlights the transformative impact of digital-assisted technologies in the management of complex orthodontic cases, such as impacted mandibular lateral incisors. The successful integration of these advanced tools with a nonextraction treatment approach underscores their potential to significantly enhance clinical outcomes. Digital technologies not only improve the accuracy and effectiveness of treatment but also facilitate a multidisciplinary approach that elevates the standard of patient care in addressing complex orthodontic challenges.

Facial soft tissue characteristics of patients with different types of malocclusion.

BACKGROUND: This study aimed to investigate the facial soft tissue characteristics of patients with different types of malocclusion. METHODS: The 3dMD scanning data of patients with malocclusion admitted to our hospital from January 2018 to April 2022 were analyzed retrospectively. Forty-seven patients with Class I malocclusion, 43 patients with Class II malocclusion and 44 patients with Class III malocclusion were selected. All patients underwent 3dMD scans prior to orthodontic treatment. Then the differences in the 3D morphological parameters of the facial soft tissues were compared between different sexes and different types of malocclusion. Spearman's correlation was further used to analyze the correlation between each parameter and the classification of malocclusion. RESULTS: In the Class I group and Class II group, there were no significant differences in the 3D morphometric parameters of malocclusion patients of different sexes (P > 0.05). There were significant differences between Al (R)-AL (L), Ac (R)-Ac (L), Prn-Ac (L), n-Prn-Sn, and Al (R)-Al (L)/Ac (L)-Ah (L) values among the three groups of patients. Spearman correlation analysis showed that Ac (R)-Ac (L) and Al (R)-Al (L)/Ac (R)-Ac (L) were correlated with the type of malocclusion. CONCLUSION: Differences in facial soft tissues exist in patients with Class I, II, and III malocclusion. 3dMD technique may be helpful in developing an effective treatment plan prior to orthodontic treatment.

Assessing position changes of impacted third molars in treatment of class II malocclusion with premolars extraction.

INTRODUCTION: Third molars (M3) remaining impacted in Class II malocclusion characterised with sagittal mandibular deficiency is a high probability. The null hypothesis of this study is that mesioangular M3s changes position through the eruption way in Class II malocclusion treatment requiring moderate anchorage with four first premolars extraction. The aim of this study is to reconsider the decision to surgically extract impacted third molars in four premolars extraction treatment of Class II malocclusion. MATERIAL AND METHODS: The materials consisted of the pre-treatment and post-treatment lateral cephalograms and orthopantomographs of 30 individuals with skeletal and dental Class II malocclusion with a mean chronological age of 13.48 years, who were treated by the same clinician (H.G.) with four first premolar extractions via the straight wire technique at the Ankara University Faculty of Dentistry Department of Orthodontics, Ankara, Turkey. The sagittal position of the upper and lower incisors and molars, M3 position and M3 space were evaluated with the paired-t test; the relationship between the sagittal position of the upper and lower incisors and molars and the change in M3 position were evaluated with correlation analysis.  Results: The study found the retroclination and mesial movement of the upper incisors and molars, and an increase in the M3 space by the fixed orthodontic treatment. An insignificant steepening of both the upper right M3 position and the lower right M3 position was found. A statistically significant increase in the lower right and left side M3 spaces was found. Positive correlations between lower right M3 angulation and the sagittal position of the lower incisors and first molars were found. CONCLUSION: Improvement in the mesioangulation of the M3s and an increase in the M3 space were achieved in this study. Based on the findings, it is useful to review the decision for prophylactic surgical extraction of the M3s before orthodontic treatment in such cases, taking into account the risks of postoperative complications.

Comparison of AI-assisted cephalometric analysis and orthodontist-performed digital tracing analysis.

BACKGROUND: The aim of this study was to compare and evaluate three AI-assisted cephalometric analysis platforms-CephX, WeDoCeph, and WebCeph-with the traditional digital tracing method using NemoCeph software. MATERIAL AND METHOD: A total of 1500 lateral cephalometric films that met the inclusion criteria were classified as Class I, Class II, and Class III. Subsequently, 40 patients were randomly selected from each class. These selected films were uploaded to 3 AI-assisted cephalometric analysis platforms and analyzed without any manual intervention. The same films were also analyzed by an orthodontist using the NemoCeph program. RESULTS: The results revealed significant differences in key angular measurements (ANB, FMA, IMPA, and NLA) across Class I, II, and III patients when comparing the four cephalometric analysis methods (WebCeph, WeDoCeph, CephX, and NemoCeph). Notably, ANB (p < 0.05), FMA (p < 0.001), IMPA (p < 0.001), and NLA (p < 0.001) varied significantly. Linear measurements also differed, with significant differences in U1-NA (p = 0.002) and Co-A (p = 0.002) in certain classes. Repeated measurement analysis revealed variation in SNA (p = 0.011) and FMA (p = 0.030), particularly in the Class II NemoCeph group, suggesting method-dependent variability. CONCLUSION: AI-assisted cephalometric analysis platforms such as WebCeph, WeDoCeph, and CephX give rise to notable variation in accuracy and reliability compared to traditional manual digital tracing, specifically in terms of angular and linear measurements. These results emphasize the importance of meticulous selection and assessment of analysis methods in orthodontic diagnostics and treatment planning.

Facial soft tissue changes in adolescent patients treated with three different functional appliances: a randomized clinical trial.

INTRODUCTION: Patients with Class II, division 1 malocclusion generally seek treatment to improve facial esthetics. Therefore, the orthodontist needs to know the changes in the soft profile produced by functional appliances. OBJECTIVE: This study evaluated the soft tissue profile changes in patients treated during the peak of the pubertal growth spurt. METHODS: Thirty selected patients were randomized into three treatment groups: Twin Block (TB), Herbst with dental anchorage (HDA), and Herbst with skeletal anchorage (HSA). All patients had computed tomographic images: pretreatment (T1) and after 12 months of active treatment (T2). Twenty-four soft tissue cephalometric measures were analyzed. The normality of all data was assessed by the Shapiro-Wilk test. Intragroup comparisons were analyzed using the t-paired test; the inter-group comparisons were determined through ANOVA and the post-hoc Tukey test. RESULTS: At T1, no significant differences were observed between groups. At T2, in the intragroup comparison, facial soft tissue changes were statistically significant in the three groups for the lower lip, sulcus inferioris, facial soft tissue convexity in HDA group and TB group, and H angle in HDA group and HSA group, and soft tissue pogonium in TB group. In the inter-group comparison, no statistically significant differences were observed. CONCLUSION: It can be concluded that there were significant changes in soft tissue measurements that benefited Class II, division 1 patient's facial profile treated with the functional appliances Twin Block, Herbst, and Herbst with skeletal anchorage. Nevertheless, no significant differences were detected among the effects obtained by the three treatment protocols.

Digital analyses of Bolton tooth size ratios and their association to gender, angle class, and other occlusal traits: a study using a partially automated digital 3D model analysis.

BACKGROUND: This study aims to verify Bolton's values for tooth size ratios and to evaluate possible relationships to different occlusal traits using precise digital measurement methods. MATERIALS AND METHODS: Including 1000 consecutively selected patients from three study centres a digital, partially automated model analysis was performed utilizing the software OnyxCeph. The measurements comprised tooth width for calculation of anterior (AR) and overall ratio (OR) as a percentage, arch width, length, perimeter, overjet, overbite, space analysis in millimetre and the assessment of the angle classification. RESULTS: AR and OR were significantly increased compared to Bolton's ratios of 77.2% (AR) and 91.3% (OR). In the gender comparison, male patients showed larger tooth size ratios, especially in the OR. Patients with Angle Class II/1 and II/2 had smaller tooth size ratios than patients with Angle Class III and I. Thus, patients with Angle Class II/1 had the largest tooth diameters in all maxillary teeth and with Angle Class II/2 the smallest tooth sizes in the mandible. The largest tooth widths in the lower jaw were observed in the Angle Class III patient group. Furthermore, a negative correlation from AR/OR to overjet, overbite, and available space in lower jaw as well as a positive correlation to available space in upper jaw was detected. CONCLUSIONS: There is a clear correlation between the tooth size ratios and the present dysgnathia as well as other orthodontically relevant occlusal traits. This prior knowledge about our patients is extremely important to create an individualized treatment plan and enable sufficient occlusion. To achieve a functionally good occlusion with correct overjet and overbite, it is essential that the maxillary and mandibular teeth are proportional in size. Any deviation from the ideal patient in terms of tooth size, number, shape, or arch must be considered in the pre-therapeutic treatment plan in combination with the existing dysgnathia in order to be able to achieve a stable anterior and posterior occlusion with appropriate adjustments to the therapy post-therapeutically.

Lateral cephalometric parameters among Arab skeletal classes II and III patients and applying machine learning models.

BACKGROUND: The World Health Organization considers malocclusion one of the most essential oral health problems. This disease influences various aspects of patients' health and well-being. Therefore, making it easier and more accurate to understand and diagnose patients with skeletal malocclusions is necessary. OBJECTIVES: The main aim of this research was the establishment of machine learning models to correctly classify individual Arab patients, being citizens of Israel, as skeletal class II or III. Secondary outcomes of the study included comparing cephalometric parameters between patients with skeletal class II and III and between age and gender-specific subgroups, an analysis of the correlation of various cephalometric variables, and principal component analysis in skeletal class diagnosis. METHODS: This quantitative, observational study is based on data from the Orthodontic Center, Jatt, Israel. The experimental data consisted of the coded records of 502 Arab patients diagnosed as Class II or III according to the Calculated_ANB. This parameter was defined as the difference between the measured ANB angle and the individualized ANB of Panagiotidis and Witt. In this observational study, we focused on the primary aim, i.e., the establishment of machine learning models for the correct classification of skeletal class II and III in a group of Arab orthodontic patients. For this purpose, various ML models and input data was tested after identifying the most relevant parameters by conducting a principal component analysis. As secondary outcomes this study compared the cephalometric parameters and analyzed their correlations between skeletal class II and III as well as between gender and age specific subgroups. RESULTS: Comparison of the two groups demonstrated significant differences between skeletal class II and class III patients. This was shown for the parameters NL-NSL angle, PFH/AFH ratio, SNA angle, SNB angle, SN-Ba angle. SN-Pg angle, and ML-NSL angle in skeletal class III patients, and for S-N (mm) in skeletal class II patients. In skeletal class II and skeletal class III patients, the results showed that the Calculated_ANB correlated well with many other cephalometric parameters. With the help of the Principal Component Analysis (PCA), it was possible to explain about 71% of the variation between the first two PCs. Finally, applying the stepwise forward Machine Learning models, it could be demonstrated that the model works only with the parameters Wits appraisal and SNB angle was able to predict the allocation of patients to either skeletal class II or III with an accuracy of 0.95, compared to a value of 0.99 when all parameters were used ("general model"). CONCLUSION: There is a significant relationship between many cephalometric parameters within the different groups of gender and age. This study highlights the high accuracy and power of Wits appraisal and the SNB angle in evaluating the classification of orthodontic malocclusion.

Evaluation of the diagnostic ability of the Fränkel manoeuvre to detect the contributing jaw in angle class II division 1 malocclusion.

BACKGROUND: A correct diagnosis of patients with an Angle Class II malocclusion is needed to guide treatment decisions toward the contributing jaw and to achieve better treatment outcomes. The aim of the study is to evaluate the diagnostic potential of the Fränkel manoeuvre (FM) for detecting the components determining sagittal discrepancy in Angle Class II division 1. MATERIALS AND METHODS: Anonymous questionnaires containing photographs were distributed totwo groups: general practitioner (GP) dentists and orthodontists. The level of the patient's profile aesthetics before (T0) and after (T1) the manoeuvre was determined using a 100 mm visual analog scale, and the 'profile improvement' score was defined as T1 minus T0. The diagnostic ability of the FM was calculated by comparison with lateral cephalometry as a reference standard using receiver operating characteristic (ROC) curve analysis. RESULTS: A total of 102 respondents participated in the survey; 40 were orthodontists, and 62 were GP dentists. According to the post-FM images, the "profile improvement" score (T1-T0) was significantly greater in patients with mandibular retrusion than in those with maxillary protrusion (p < 0.05). The predictive power of FM, coinciding with the area under the ROC curve, was 0.62 for GPs and 0.78 for orthodontists. CONCLUSIONS: The FM method is a useful and accurate tool for diagnosing skeletal Angle Class II malocclusion etiology (mandibular retrusion or maxillary protrusion), especially when used by orthodontists.

Retrospective analysis of the upper airway anatomy and Sella turcica morphology across different skeletal malocclusions: a computerized technique.

OBJECTIVE: This study aimed to investigate the normal volumetric space and variations in the measurements of different landmarks in adults with different skeletal relations of the maxilla and the mandible based on CBCT data. The study also analyses these landmarks to locate any correlations. BACKGROUND: Numerous studies in orthodontics have found a relationship between orthodontic treatment and changes in the anatomy and function of the airway. Severe changes in airway morphology can cause breathing difficulties, lower quality of life, and even result in life-threatening conditions such as obstructive sleep apnoea. Consequently, orthodontic diagnosis and treatment planning require a thorough understanding of the airway space and its function. METHODS: The present retrospective study was conducted using CBCT records of 120 adult patients, containing 40 samples of each skeletal class (20 males and 20 females). The boundaries were defined for the 3 major regions: the nasopharynx, the oropharynx, and the hypopharynx. Various measurements were recorded across these regions, as well as selective cephalometric landmarks. The obtained data was used to calculate average and standard deviation, while regression analysis was used to evaluate correlations and t-test was used to test statistical significance of gender differences. RESULTS: The results demonstrate that skeletal Class III individuals exhibit a reduced airway volume in the nasopharynx compared to other groups, whereas skeletal Class II individuals displayed a diminished airway volume in the hypopharynx. A strong correlation was observed for Sella turcica parameters. There were no significant differences in skeletal parameters across genders. Nasopharynx cavity volume demonstrated significant differences between skeletal Class I-Class III as well as between skeletal Class II-Class III. Hypopharynx cavity volume also demonstrated significant differences between skeletal Class I-Class II and between skeletal Class II-Class III. CONCLUSION: The major findings are the presence of a reduced nasopharyngeal volume in skeletal Class III malocclusions while skeletal Class II individuals displayed a diminished hypopharyngeal volume, making these critical areas to consider during the diagnostic and orthodontic treatment planning stages. This study also revealed a consistent correlation between Sella turcica parameters across various facial skeletal profiles, with skeletal Class II patients exhibiting a distinct pattern and skeletal Class I and Class III demonstrating an average relationship.

Comparison between clear aligners and twin-block in treating class II malocclusion in children: a retrospective study.

The study herein evaluated and compared the efficacy of Clear Aligners (CA) and Twin-Block (TB) appliances as the early orthodontic treatments of developing class II division 1 malocclusion. Twenty-four patients each for CA (11.73 ± 0.33 y) and TB (11.87 ± 0.34 y) groups were selected according to the inclusion and exclusion criteria. The cephalometric X-rays and intraoral photos were taken for the patients after nearly 12 months of treatment. Treatment impacts were evaluated by the molar correction and overjet reduction. The vertical and sagittal changes were analyzed through cephalometric measurements. Sella-nasion-point B angle (SNB), point A-nasion-point B angle (ANB), Wits Appraisal (AO-BO) and overjet were statistically significant regarding the sagittal changes analyzed before and after the treatments in both groups, respectively. So, no significant difference was noted in the sagittal changes between CA and TB groups. However, for the vertical changes, OP (occlusal plane) angle of CA group and OP angle, AFH (anterior facial height) and PFH (posterior facial height) of TB group were statistically significant. Moreover, the Z angle and cranial facial difficulty (C.F. difficulty) were also statistically significant in both groups. Class II children with retrognathic mandible are effectively treated by employing the CA, which has almost the same impact as of TB in sagittal and vertical changes. Resultantly, the patient profile is improved. The CA and TB treatments thus minimize the subsequent treatment difficulty by reducing the C.F. difficulty.

Relationship between interincisal angles and TMJ morphology/position and trabecular structure: a retrospective study.

BACKGROUND: TMJ morphology/position and trabecular structure are influenced by various factors. The role of the interincisal angle, an indicator of the anterior occlusal relationship, on TMJ remains unclear. This study aims to investigate the morphology, trabecular bone structure, and position of the condyle, as well as the glenoid fossa's morphology in skeletal class II populations with different interincisal angles. MATERIALS AND METHODS: A total of 150 adult patients with normodivergent facial types and skeletal class II malocclusions were selected and divided into three groups based on their interincisal angles: normal, small, and large angle groups. The indexes of TMJ were measured using cone-beam computed tomography (CBCT) data and analyzed using Dolphin Imaging, Mimics, and ImageJ. RESULTS: The small angle group had the smallest anteroposterior diameter (APD), while the large angle group had a greater mediolateral diameter (MLD). The large angle group exhibited significantly the largest maximum axial area, bone surface area, and bone volume (P < 0.05). Small and large angle groups exhibited greater bone trabeculae (Tb. N) and thinner trabecular thickness (Tb. Th). Compared to the normal angle group, the small angle group exhibited a larger horizontal condylar angle and smaller bilateral condylar angles on the axial plane, while the large angle group showed the opposite trend. Small and large angle groups showed a reduced vertical condyle angle on the coronal plane, with the largest reduction observed in the large angle group (P < 0.05). Small and large angle groups had higher heights of the glenoid fossa (GFH). The large angle group exhibited the greatest GFH and width of the glenoid fossa (GFW) (P < 0.05). CONCLUSION: The large angle group had elongated oval and large condyles, and deeper glenoid fossae, while a flattened-oval and smaller condyle, and wider and shallower glenoid fossae were observed in the small angle group. Small and large interincisal angle affects the structure of condylar trabeculae, resulting in thinner Tb. Th and greater Th. N. In the condylar position, small and large angle groups exhibit condylar rotation in the axial and coronal planes. Therefore, the interincisal angle affects the morphology, position, and trabecular structure of the TMJ. This implies that we must pay attention to the impact of the interincisal angle on TMJ, and it is crucial to restore the normal interincisal angle during orthodontic treatment.

Credibility of Pont's index in Egyptian population.

BACKGROUND: Many indices have been suggested to help orthodontists in predicting the ideal dental arch width. One of these was Pont's index which was established by Pont. He suggested equations to predict the ideal maxillary dental arch width (interpremolar and intermolar) from the combined mesiodistal width of the maxillary incisors. This study aimed to test the applicability of Pont's index as an orthodontic diagnostic tool in Egyptian population and to compare the results with those obtained from studies of different ethnic subjects. METHODS: This study was performed using dental casts of 184 Egyptian individuals (82 males and 102 females; age range, 19-24 years). The casts were divided into 46 casts with normal occlusion, 46 casts with class I, 46 casts with class II and 46 casts with class III malocclusion, according to Angle's classification. Alginate impressions were taken for all patients and poured immediately using dental plaster. The real models were transformed into digital models using three-dimensional laser scanner to allow digital model analysis. Predicted arch widths were calculated using Pont's equations. The predicted values were compared to the measured values. RESULTS: Intra class correlation coefficient (ICC) (absolute agreement) between measured and predicted arch widths was determined. Poor absolute agreement was found between measured arch width values and the corresponding values calculated according to Pont's index. CONCLUSION: According to the results of this study, Pont's index is not a reliable method for predicting the ideal dental arch widths in Egyptian populations.

Facial asymmetry outcome of orthognathic surgery in mild craniofacial microsomia compared to non-syndromic class II asymmetry.

OBJECTIVES: To compare the facial asymmetry after bimaxillary surgery between mild craniofacial microsomia (CFM) and non-syndromic class II asymmetry. MATERIALS AND METHODS: Cone-beam computed tomography scans of adults with Pruzansky-Kaban types I and IIA CFM (CFM groups, n = 20), non-syndromic skeletal class II asymmetry (Class II group, n = 20), and normal controls (control group, n = 20) were compared. The area asymmetry of lower face and jaw bones was quantified. Landmark-based method was used to evaluate the lower facial asymmetry regarding midline, cants, and contour. RESULTS: There were no significant postoperative differences in the hemi-facial and hemi-jaw area asymmetry between CFM and Class II groups, both of which were significantly larger than the control group. No significant difference was found in the midline deviation and lip and occlusal cants between CFM and Class II groups. The vertical contour asymmetry in CFM group became significantly larger than Class II group. Compared to the control group, the deviation of pronasale, subnasale, and soft-tissue menton, lip and occlusal cants, and sagittal and vertical contour asymmetry in CFM group were significantly larger, as were the deviation of subnasale and soft-tissue menton and vertical contour asymmetry in Class II group. CONCLUSIONS: The vertical contour asymmetry of mild CFM was significantly larger than non-CFM class II after surgery, while the area asymmetry, midline deviation, cants, and sagittal contour asymmetry of lower face showed no significant difference. CLINICAL RELEVANCE: Be aware that correcting vertical asymmetry of contour, lip, and dentition in CFM is still challenging.

Network analysis of three-dimensional hard-soft tissue relationships in the lower 1/3 of the face: skeletal Class I-normodivergent malocclusion versus Class II-hyperdivergent malocclusion.

BACKGROUND: The determining effect of facial hard tissues on soft tissue morphology in orthodontic patients has yet to be explained. The aim of this study was to clarify the hard-soft tissue relationships of the lower 1/3 of the face in skeletal Class II-hyperdivergent patients compared with those in Class I-normodivergent patients using network analysis. METHODS: Fifty-two adult patients (42 females, 10 males; age, 26.58 ± 5.80 years) were divided into two groups: Group 1, 25 subjects, skeletal Class I normodivergent pattern with straight profile; Group 2, 27 subjects, skeletal Class II hyperdivergent pattern with convex profile. Pretreatment cone-beam computed tomography and three-dimensional facial scans were taken and superimposed, on which landmarks were identified manually, and their coordinate values were used for network analysis. RESULTS: (1) In sagittal direction, Group 2 correlations were generally weaker than Group 1. In both the vertical and sagittal directions of Group 1, the most influential hard tissue landmarks to soft tissues were located between the level of cemento-enamel junction of upper teeth and root apex of lower teeth. In Group 2, the hard tissue landmarks with the greatest influence in vertical direction were distributed more forward and downward than in Group 1. (2) In Group 1, all the correlations for vertical-hard tissue to sagittal-soft tissue position and sagittal-hard tissue to vertical-soft tissue position were positive. However, Group 2 correlations between vertical-hard tissue and sagittal-soft tissue positions were mostly negative. Between sagittal-hard tissue and vertical-soft tissue positions, Group 2 correlations were negative for mandible, and were positive for maxilla and teeth. CONCLUSION: Compared with Class I normodivergent patients with straight profile, Class II hyperdivergent patients with convex profile had more variations in soft tissue morphology in sagittal direction. In vertical direction, the most relevant hard tissue landmarks on which soft tissue predictions should be based were distributed more forward and downward in Class II hyperdivergent patients with convex profile. Class II hyperdivergent pattern with convex profile was an imbalanced phenotype concerning sagittal and vertical positions of maxillofacial hard and soft tissues.

Does mandibular advancement ortho-surgical procedure cause condyle changes? A case-series analysis.

INTRODUCTION: Mandibular advancement surgery corrects bone bases while establishing patients' functional and aesthetic rehabilitation. However, little is known about the results of this procedure in the structures that make up the stomatognathic system, as the condyles. OBJECTIVE: This study aimed to evaluate the structural and positional changes of mandibular condyles in ortho-surgical patients who underwent mandibular advancement surgery. MATERIAL AND METHODS: A prospective investigation was conducted with cone-beam computed tomography images. Using Dolphin Imaging® software, seven ortho-surgical patients with Angle Class II malocclusion and mandibular deficiency were evaluated. The images assessed were obtained at pre-surgical phase and after, at least, 1 year of the procedure. To study the structural and positional changes of condyles, linear and angular measurements were obtained, and the right and left sides of patients were compared. Descriptive statistical analysis was performed and, in order to verify possible significant differences, normality tests (Kolmogorov-Smirnov) were applied, followed by a paired t-test to define significance. RESULTS: For all measures evaluated in this study, no statistically significant differences were found. CONCLUSION: The ortho-surgical procedure performed did not change the structure and position of the condyles of patients who underwent surgical mandibular advancement. Right and left mandibular condyles behaved similarly, suggesting stability and condylar adaptation after surgery.

Clinical effects of twin-block combined with maxillary expansion on the upper airway in adolescents with Class II malocclusion.

BACKGROUND: Class II malocclusion, particularly class II division 1, poses a significant orthodontic challenge with implications for both aesthetics and health. This study aimed to explore the impact of twin-block (TB) combined with maxillary expansion treatment (TB-ME) on upper airway dimensions and inflammatory profiles in adolescents with skeletal Class II Division 1 malocclusion in adolescent. METHODS: Ninety-two eligible patients were randomly assigned to two groups: TB-ME treatment and traditional McLaughlin Bennett Trevisi (MBT) straight-wire orthodontic treatment (Control). Cephalometric lateral X-ray scans were conducted before and after treatment to assess skeletal changes, including SNA, ANB, and SNB angles, which are essential to assess the anteroposterior relationships of the maxilla and mandible to the cranial base. We also measured the upper airway volumes and areas. Concentrations of inflammatory factors including intercellular adhesion molecule 1 (ICAM-1), matrix metallopeptidase 2 (MMP2), and interleukin 8 (IL-8) of gingival crevicular fluid analysis (GCF) were detected by enzyme-linked immunosorbent assay. RESULTS: TB-ME treatment induced significant improvement in cephalometric parameters, including a decrease in SNA and ANB angles and an increase in SNB angle. Upper airway volumes and areas increased significantly in both groups, with TB-ME showing greater improvements. GCF analysis revealed a reduction in ICAM-1, MMP2, and IL-8 concentrations in the TB-ME group compared to the Control group. CONCLUSIONS: TB-ME treatment demonstrates multifaceted improvements in skeletal malocclusion, upper airway dimensions, and inflammatory profiles in adolescents with class II division 1 malocclusion, showing the promise of TB-ME in addressing the complexities associated with class II malocclusion.

The correlation analysis between incisal guidance angle and occlusal plane angles and temporomandibular joint morphology.

OBJECTIVES: The correlations between the incisal guidance angle (IGA) and occlusal plane angles and temporomandibular joint (TMJ) morphology were investigated in adults with skeletal Class II division II malocclusion. MATERIALS AND METHODS: CBCT images of 37 patients were analyzed. It included 19 cases of skeletal Class II division II malocclusion with low angle (study group) and 18 cases of skeletal Class I average angle (control group). The Invivo Dental 5 software was employed to acquire the data of the incisal guidance angle (IGA), occlusal plane angle (FH-OP), anterior occlusal plane angle (FH-AOP) and the TMJ measurement items. RESULTS: The results of IGA, FH-AOP angle and FH-OP angle showed the study group > the control group (P < 0.05). There were statistically difference in the condylar mediolateral diameters, articular eminence inclination and height, and posterior joint spaces between two groups. No differences were revealed in the condylar anteroposterior diameters, the condylar inclination angle, condylar head width and height, condylar length, glenoid fossa depth and width between two groups. In the study group, IGA showed a moderate correlation with FH-AOP, a weak correlation with FH-OP and condylar mediolateral diameters. Meanwhile, there was a correlation between FH-AOP, FH-OP, and TMJ indicators. CONCLUSIONS: The IGA was not only related to FH-AOP and FH-OP, but also to the condylar mediolateral diameters. In addition, there was a correlation between the occlusal plane angles and TMJ morphology in skeletal Class II division II low angle malocclusion. CLINICAL RELEVANCE: For patients with skeletal Class II division II low angle malocclusion, adjusting the IGA and the occlusal plane angles could improve the esthetic appearance of the anterior teeth, occlusal function, and TMJ morphology.

Prevalence of condylar morphological changes in individuals with class II malocclusion.

This observational, cross-sectional study with retrospective collection was aimed to evaluate the prevalence of morphological changes in mandibular condyles in individuals with class II malocclusion, classified according to different vertical growth patterns (brachyfacial, mesofacial, and dolichofacial), through cone beam computed tomography (CBCT). Seventy CBCT images (140 mandibular condyles) were selected from individuals without orthodontic treatment, of both sexes, aged between 25 and 50 years. No statistically significant differences were found between facial patterns; however, there was a higher relative prevalence of bone changes in dolichofacial individuals with flattening (62%), sclerosis (44%), and subchondral bone cyst (20%). Erosion and osteophytes prevailed in mesofacial (39%), and brachyfacial individuals (32%), respectively. Thus, there was no statistically significant difference in the prevalence of degenerative changes between the vertical skeletal patterns. Flattening was the most prevalent change, whereas subchondral bone cyst was the least prevalent among the three groups studied. The observational design of this study makes it possible to analyze image banks to verify the correlation of morphological changes in the temporomandibular joint in different facial patterns in patients with class II malocclusion. A limitation of the study is that clinical characteristics were not evaluated.