Three-dimensional assessment of the temporomandibular joint and mandibular dimensions after early correction of the maxillary arch form in patients with Class II division 1 or division 2 malocclusion

Recommendations for standard criteria for the positional and morphological evaluation of temporomandibular joint osseous structures using cone-beam CT: a systematic review

OBJECTIVE

This systematic review aimed to appraise the reliability and comprehensiveness of imaging methods in studies that used three-dimensional assessment of the temporomandibular joint (TMJ) in order to propose a standardized imaging method.

METHODS

Six databases/search engines were searched up until September 2022. The outcomes of interest included measurements of the mandibular condyle, glenoid fossa, joint spaces, or the entire TMJ. Two checklists were utilized: one to assess the risk of bias, with a maximum score of 37, and the other, a pre-designed checklist consisting of 22 items to evaluate the comprehensiveness of the methods used, with a maximum score of 33.

RESULTS

Out of the 2567 records retrieved, only 14 studies, which used cone bean computed tomography (CBCT), were deemed eligible and thus included in the qualitative analysis. Three studies were deemed of low risk of bias, while the remaining studies were rated as moderate to high risk of bias, primarily due to improper reporting of inter-observer agreement, varying reliability values, and a limited number of cases included in the reliability analysis. Regarding the comprehensiveness of the methods used, only four studies achieved relatively high scores. The deficiencies observed were related to the reporting of variables such as slice thickness and voxel size, absence of or improper reporting of intra- and inter-examiner reliability analyses, and failure to assess all osseous components of the TMJ.

CONCLUSION

CBCT-based methods used to assess the positions and morphology of TMJ bony structures appear to be imperfect and lacking in comprehensiveness. Hence, criteria for a standardized assessment method of these TMJ structures are proposed.

CLINICAL RELEVANCE STATEMENT

Accurately, comprehensively, and reliably assessing the osseous structures of the temporomandibular joint will provide valid and valuable diagnostic features of the normal temporomandibular joint, and help establish potential associations between these osseous features and temporomandibular disorders.

REGISTRATION

The protocol for this systematic review was registered at the International Prospective Register of Systematic Reviews (PROSPERO, No.: CRD42020199792).

KEY POINTS

•Although many methods have been introduced to assess the osseous structure of the temporomandibular joint, they yielded inconsistent findings. •None of the published studies comprehensively assessed the temporomandibular joint. •Recommendations for a comprehensive temporomandibular joint osseous assessment method were suggested for better validity and reliability of future research.

Comparison of the condyle-fossa relationship and resorption between patients with and without Juvenile Idiopathic Arthritis (JIA)

INTRODUCTION

The most common disease in pediatric rheumatology is juvenile idiopathic arthritis (JIA). JIA is considered to be an autoimmune disease with an onset before the age of 16. The temporal mandibular joint (TMJ) has been reported to be involved in up to 87% of patients with JIA. Even though substantial research has been conducted on JIA, limited research has studied to understand its effect on the condyle-fossa relationship and to evaluate resorption amount on condyle by using a scoring system.

AIM

The purpose of this study was 1) to compare condyle - fossa relationships in the temporomandibular joint (TMJ), 2) was to score condylar resorption by using a TMJ indexing system in patients with JIA and without JIA.

METHODS

The present retrospective cross-sectional study included cone-beam computed tomography (CBCT) images obtained from the sagittal, coronal, and axial slices. In the multidisciplinary Pediatric Rheumatology Outpatient Clinic at The University of Alabama at Birmingham (UAB) children with JIA are also examined by a group of orthodontists working in the same institute from October 2018 to July 2019. The predictor variable consists of patients with JIA and without JIA. The primary outcome variables are the depth of the mandibular fossa, joint spaces, axial angles, medio-lateral width, and condyle resorption. Other study variables were age and sex. In this study, the measurements obtained from 2 different groups (with JIA and without JIA) are compared using a t-test, where Tukey is utilized to adjust for multiple comparisons. The left and right joints are analyzed separately as the paired t test conducted showed a significant difference between the 2 joints (P < .05).

RESULTS

The study was comprised of 34 patients diagnosed with JIA and 34 healthy subjects. The depth of the mandibular fossa, the anterior joint spaces, the axial angles, and the resorption index showed statistically significant differences between the JIA and healthy groups in both left and right sides (P < .05). However, there was no statistically significant difference in the posterior joint spaces and mediolateral width between JIA and healthy groups in both sides (P > .05).

CONCLUSIONS

The results of our study presented the destructive potential of juvenile idiopathic arthritis by using CBCT. CBCT scanning is a helpful tool in the evaluation of the radiographic result of TMJ.

Cone beam computed tomographic evaluation of the changes in condylar position in growing patients with unilateral posterior crossbite undergoing rapid maxillary expansion followed by fixed orthodontic therapy

PURPOSE

This study aimed at assessing changes in condylar position (CP) in growing patients with unilateral posterior crossbite (UPC) undergoing rapid maxillary expansion (RME) followed by fixed orthodontic treatment (FOT) (experimental-group); and growing patients without posterior crossbite (PC) treated with FOT alone (control-group).

METHODS

Cone beam computed tomography (CBCT) images were obtained before treatment (T0), 6 months after RME (T1) and after FOT (T2) for the experimental-group (n = 19); and at T0 and T2 for the control-group (n = 22). Condylar position-related measurements including the anterior joint space (AJS), superior joint space (SJS), posterior joint space (PJS), lateral position of condyle (LC) and condylar angle (CA) were measured. Non-parametric tests were used.

RESULTS

On the crossbite side, significant increases were found in LC (P = 0.039) and CA (P = 0.007), and on the non-crossbite side significant increases were observed in SJS (P = 0.027) and LC (P = 0.001) between T0, T1 and T2 in patients with UPC. On the right and left sides in the control-group, significant increases were identified in LC (P < 0.001 and P = 0.012, respectively) between T0 and T2.

CONCLUSIONS

In growing patients with UPC, RME followed by FOT is associated with significant changes in CP-related measurements.

Effects of rapid maxillary expansion on temporomandibular joints

OBJECTIVE

To evaluate the impact of rapid maxillary expansion (RME) on the condylar position, disc joint, joint space, and interarticular relationship in growing patients.

MATERIALS AND METHODS

A systematic search was performed in nine databases. The clinical studies selected included those with pre- and post-magnetic resonance, conventional computed tomography or cone beam tomography in growing patients. Risk of bias assessment was performed using the Cochrane Collaboration tool for controlled clinical studies and National Heart, Lung, and Blood Institute (NHLBI) Quality Assessment for Before-After Studies With No Control Group.

RESULTS

Initially, 4303 records were identified. Only eight studies fulfilled the criteria and were included in the qualitative analysis. Of those, two were controlled clinical studies with a risk of uncertain to high bias. The remaining papers had a low to moderate risk of bias. Results showed that RME in children and adolescents promoted the following: remodeling in the head and or condylar branch, changes in condylar position and joint space, maintenance of improved symmetry between the condyles, and no ability to modify the position or shape of the articular disc.

CONCLUSIONS

RME in growing patients is able, in the short term, to modify the condyle-fossa relationship but does not change the position or shape of the articular disc. The intercondylar symmetric relationship is maintained or improved. Although the NHLBI score shows low to moderate risk of bias, the clinical relevance of these review findings is limited by Cochrane and Grades of Recommendation, Assessment, Development and Evaluation scores.

Evaluation of the Effect of Fixed Anterior Biteplane Treatment on Temporomandibular Joint in Patients with Deep Bite

OBJECTIVE

To investigate the effects of fixed anterior biteplane treatment on temporomandibular joint in deep bite patients.

METHODS

The sample comprised 17 Class II patients with deep bite and decreased lower anterior facial height. The average patient age was 9.9±0.9 years. Transcranial temporomandibular joint radiographs were obtained from the subjects before (T0) and after fixed anterior biteplane treatment (T1). Anterior joint space, posterior joint space, superior joint space, anteroposterior thickness of the condylar head, vertical height of the articular fossa, and the articular fossa slope were measured on temporomandibular joint radiographs to evaluate the position of the mandibular condyles in the glenoid fossa.

RESULTS

The average treatment duration was 8.5±2.1 months. Slope of the articular fossa, vertical height of the articular fossa, anteroposterior thickness of the condyle, posterior joint space, superior joint space, and anterior joint space showed no statistically significant difference between T0 and T1 (p>0.05).

CONCLUSION

Fixed anterior biteplane appliance treatment did not change the condyle fossa relationship in Class II deep bite patients at the time of appliance removal.

Cone-beam CT evaluation of temporomandibular joint in permanent dentition according to Angle's classification

OBJECTIVES

To compare characteristics of temporomandibular joint (TMJ) and related structures according to Angle class I, II¹, II², and III.

METHODS

123 Chinese patients (13-36 years old, 60 males, and 63 females) were classified in four groups according to Angle's classification: skeletal class I (31 patients), skeletal class II division 1 (30 patients), skeletal class II division 2 (30 patients), and skeletal class III (32 patients). Left and right TMJs of each subject were evaluated independently with cone-beam computed tomography (CBCT). The position of condyle in the joint fossa was analyzed according to Pullinger.

RESULTS

There were significant differences between class III subjects and class I, II¹, II² in the superior joint space (p < 0.05). Compared with class II¹, II², and III subjects, the height and diameter of condyle in class I was significantly larger (p < 0.05). The width of joint fossa was significantly larger in Angle class III than in Angle class I, II¹, and II², while the depth was significantly smaller. The condyle position in class III subjects was more anteriorly displaced compared with that in class I subjects. In class II² patients, the condyle position was mainly concentric and posterior.

CONCLUSIONS

There are significant differences in condylar morphology, joint space, joint fossa morphology, and condylar position between different Angle classifications.

Reliability of cone-beam computed tomography for temporomandibular joint analysis

Objective

The aim was to assess the intraobserver and interobserver reliabilities of temporomandibular joint linear measurements and condylar shape classifications performed with cone-beam computed tomography (CBCT).

Methods

CBCT images of 30 patients were measured at two different time points by two orthodontists using the Dolphin 3D program (n = 60). Anterior, posterior, and superior joint space measurements and sagittal joint morphology classification in the sagittal view and medial and lateral joint space and mediolateral width measurements and coronal joint morphology classification in the coronal view were recorded. Intraclass-interclass correlation coefficients (ICC) and kappa statistics were used to assess intraobserver and interobserver reliability for the measurements and morphology classifications, respectively.

Results

The ICC values were good for measurements of the posterior joint space by observer I and for measurements of the posterior, medial, and lateral joint spaces by observer II, while the other intraobserver measurements were excellent. Only the mediolateral width measurements showed excellent interobserver ICC values, while the other measurements showed good interobserver ICC values. Intraobserver agreement for the sagittal morphology classifications was moderate (κ = 0.479) and almost perfect (κ = 0.858) for observers I and II, respectively, while the corresponding agreement for the coronal morphology classifications was substantial for both observers. The interobserver agreement values for sagittal and coronal morphology classifications were slight (κ = 0.181) and fair (κ = 0.265), respectively.

Conclusions

Linear temporomandibular joint measurements were reproducible and reliable in both intraobserver and interobserver evaluations. However, interobserver agreement for assessments of condylar shape was low.

Correction of Deep Overbite by Using a Modified Nance Appliance in an Adult Class II Division 2 Patient with Dehiscence Defect

A modified Nance Appliance (MNA) is introduced as a treatment option for an adult class II division 2 malocclusion (CII/2) patient with deep overbite and dehiscence on the facial root surface of retroclined upper incisors through the cone-beam computed tomography (CBCT). Indications for this modified MNA as well as a brief description of fabrication procedure and biomechanical analysis of the treatment effects are shown in detail. Root control and absolute intrusion without enlarging the bony defect were achieved. The treatment results were satisfying and favorable.

Computed tomography assessment of temporomandibular joint position and dimensions in patients with class II division 1 and division 2 malocclusions

Background

This study aimed to investigate and compare the positions and dimensions of the temporomandibular joint and its components, respectively, in patients with Class II division 1 and division 2 malocclusions.

Material and Methods

Computed tomography images of 14 patients with Class II division 1 and 14 patients with Class II division 2 malocclusion were included with a mean age of 11.4 ± 1.2 years. The following temporomandibular joint measurements were made with OsiriX medical imaging software program. From the sagittal images, the anterior, superior, and posterior joint spaces and the mandibular fossa depths were measured. From the axial images, the greatest anteroposterior and mediolateral diameters of the mandibular condyles, angles between the long axis of the mandibular condyle and midsagittal plane, and vertical distances from the geometric centers of the condyles to midsagittal plane were measured. The independent samples t-test was used for comparing the measurements between the two sides and between the Class II division 1 and 2 groups.

Results

No statistically significant differences were observed between the right and left temporomandibular joints; therefore, the data were pooled. There were statistically significant differences between the Class II division 1 and 2 groups with regard to mandibular fossa depth and anterior joint space measurements.

Conclusions

In Class II patients, the right and left temporomandibular joints were symmetrical. In the Class II division 1 group, the anterior joint space was wider than that in Class II division 2 group, and the mandibular fossa was deeper and wider in the Class II division 1 group.

Key words:Temporomandibular joint, Class II malocclusion, Cone beam computed tomography.