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

Position and Dimensions of the Mandibular Condyle in Various Anterior-Posterior Skeletal Patterns: A CBCT Imaging Study in a Sample of Iranian People

Purpose: The aim of this comparative observational study is to evaluate and compare the size and position of the condyle among male and female patients with different skeletal patterns in the anterior-posterior dimension using cone beam computed tomography (CBCT) images. Materials and Methods: CBCT images of 120 patients, all prepared for other treatment purposes under the same conditions, were included in the study. The patients were classified into three groups-class I, class II, and class III-based on ANB angles and Wits analysis. The size of the condyle was measured in terms of width, height, and length. The position of the condyle was assessed by measuring the superior joint space (SS), anterior joint space (AS), and posterior joint space (PS) on the right and left sides separately. The measurements and results were analyzed using analysis of covariance (ANCOVA) and Bonferroni analysis. A statistical significance level of p  < 0.05 was considered. Results: The study found no statistically significant differences in the size of the SS and AS (p = 0.481 and p = 0.392, respectively) across different skeletal patterns. However, the size of the PS was significantly greater in class I subjects compared to class III subjects (p = 0.015). There were no statistically significant differences in condyle height and width among the different skeletal patterns (p = 0.367 and p = 0.720, respectively). In contrast, condyle length was statistically significant in class II individuals (p = 0.002) and was the lowest among the other skeletal pattern groups. Conclusions: Based on the results obtained, class I individuals have lower PS values compared to class III individuals. Additionally, class II individuals have shorter condyle lengths compared to those in class III and class I.

Three-Dimensional Assessment of the Condylar Position in Different Malocclusions Using Cone-Beam Computed Tomography: A Cross-Sectional Study

Introduction The role of the condylar position in the correct functioning of the stomatognathic system has been the center of the study. Using cone-beam computed tomography (CBCT), this study looked at the three-dimensional (3D) position of the condylar bone in patients from Class I, Class II, Division 1, and Division 2. Materials and methods This cross-sectional, retrospective study was conducted using 102 CBCT records, with 34 records allocated to each category of malocclusion classification, such as dentoskeletal Class I, skeletal Class II, and dental Class II, Division 1 and 2. CBCT scans were conducted utilizing a Carestream New Generation CBCT apparatus (Carestream Dental, Atlanta, Georgia) in accordance with a standardized protocol (operating at a voltage of 120 kV, a current of 80 mA, a seven-second scan time, a field of view (FOV) measuring 10 x 10 cm, and a resolution of 0.2 voxels, and 1-mm slice thickness). The condylar position was assessed as the superior, inferior, and medial distance of the condyle from the glenoid fossa, along with the condylar angle. The distance from the most anterior point on the anterior surface of the condyle to the articular eminence was taken as anterior condylar distance; the distance of the superior surface of the condyle from the deepest point of the glenoid fossa was taken as superior condylar distance; the distance of the posterior surface of the condyle from the glenoid fossa was taken as posterior condylar distance; the condylar angle was measured as an angle between the XY line and the FH' line passing through X, where X is the center of the condyle; and the distance of the medial surface of the condyle from the glenoid fossa was taken as medial distance. The data were then subjected to statistical analyses. Results For anterior distance, the highest distance was noted in Class II Division 1 (3.32 ± 0.4 mm), and the lowest was seen in Class I (2.43 ± 0.26 mm). In the posterior distance, Class I exhibited the highest mean distance of 2.05 ± 0.14 mm, while Class II Division 1 showed the lowest distance of 1.83 ± 0.18 mm. For superior distance, the highest mean value was noticed in Class I patients at 2.92 ± 0.22 mm, and the lowest value was seen in Class II Division 1 at 2.61 ± 0.35 mm (p=0.001). For the condylar angle, the highest mean value was observed in Class I (30.96 ± 1.910) and the lowest in Class II Division 1 (26.71 ± 1.480), with p=0.001. Confirmatory factor analysis revealed that the most substantial loading was attributed to the condylar angle at -2.28, signifying its significant contribution to Fc1. Conclusion The condyle was placed anteriorly, superiorly, and medially in Class II Division 1 and posteriorly in Class II Division 2, compared to Class I patients.

Is the positioning guide mandatory for the virtual planning of orthognathic surgery? A randomized double-blind trial

OBJECTIVES

The aim of this study is to verify the positioning of the condyles in computed tomography (CT) scans of skeletal Class II and Class III patients in virtual surgical planning before orthognathic surgery. The secondary aim is to determine whether occlusal devices are mandatory for performing a CT examination.

MATERIALS AND METHODS

In this retrospective randomized double-blind study, 42 CT scans were evaluated from patients who had undergone to orthognathic surgery at the University Hospital of the University of São Paulo. Male and female patients between the ages of 25 and 40 were included. The sample consisted of skeletal Class II and III patients. The CTs were randomly selected into centric relation (CR) and maximal intercuspal position (MI). Statistical analysis was performed with R Statistical Package and was considered significant in the case of p < 0.0001.

RESULTS

A total of 504 measurements were carried out in 42 patients. Three joint spaces on each side were used. No statistically significant difference between the inter- and intraobservers was found for CR and MI. Some scores were performed to avoid the risk of gender bias.

CONCLUSIONS

No statistically significant value was found between patients in CR and MI after mandibular manipulation. The use of a positioning guide to perform a CT scan prior to virtual planning is not absolutely necessary.

Association between the Temporomandibular Joint Morphology and Chewing Pattern

This study aimed to investigate whether the morphology of the temporomandibular joint (TMJ) is associated with chewing patterns while considering skeletal morphology, sex, age, and symptoms of temporomandibular disorder (TMD). A cross-sectional observational study of 102 TMJs of 80 patients (age 16-40 years) was performed using pretreatment records of cone-beam computed tomography imaging of the TMJ, mandibular kinesiographic records of gum chewing, lateral and posteroanterior cephalometric radiographs, patient history, and pretreatment questionnaires. To select appropriate TMJ measurements, linear regression analyses were performed using TMJ measurements as dependent variables and chewing patterns as the independent variable with adjustment for other covariates, including Nasion-B plane (SNB) angle, Frankfort-mandibular plane angle (FMA), amount of lateral mandibular shift, sex, age, and symptoms of TMD. In multiple linear regression models adjusted for other covariates, the length of the horizontal short axis of the condyle and radius of the condyle at 135° from the medial pole were significantly (p < 0.05) associated with the chewing patterns in the frontal plane on the working side. "Non-bilateral grinding" displayed a more rounded shape of the mandibular condyle. Conversely, "bilateral grinding" exhibited a flatter shape in the anteroposterior aspect. These findings suggest that the mandibular condyle morphology might be related to skeletal and masticatory function, including chewing patterns.

Three-Dimensional Assessment of Temporomandibular Joint Morphology and Facial Asymmetry in Individuals with Different Vertical Skeletal Growth Patterns

The aim of the current study was to investigate, by means of Cone-Beam Computed Tomography (CBCT), condyle−fossa relationship, temporomandibular joint (TMJ) morphology and facial asymmetry in subjects with different vertical skeletal growth patterns. CBCT of 56 patients (112 TMJs) were categorized into three groups according to the mandibular plane angle (MP): Hypodivergent (MP ≤ 23°), Normodivergent (23° < MP < 30°), and Hyperdivergent (MP ≥ 30°). TMJ spaces, width and depth of the condyle and thickness of the fossa were measured. Horizontal and vertical measurements were used to assess facial asymmetry. One-way Analysis of Variance (ANOVA) and post-hoc Turkey tests were computed for the between-groups comparison. Statistical significance was set at p < 0.05. Larger anterior joint space and smaller condylar dimensions (medio-lateral diameter and medio-lateral thickness) were observed in the hyperdivergent group compared to the normodivergent and hypodivergent groups. Right condylar distances to midsagittal plane were significantly larger than left distances in all the three groups. A vertical pattern of growth in healthy individuals seems to be associated with condylar position and dimension, while facial asymmetry values do not differ among different vertical groups.

Evaluation of the Mandibular Condyle Morphologic Relation before and after Orthognathic Surgery in Class II and III Malocclusion Patients Using Cone Beam Computed Tomography

Simple Summary

In individuals with severe malocclusions, orthognathic surgery seeks to rebalance the relationships between the jaws by providing a stable occlusion, a healthy muscle balance, and the functioning of the temporomandibular joint. Cone beam computed tomography may be used to determine the position of the mandibular condyle in the glenoid fossa. This study aimed to assess how the position of the mandibular condyle varies in class II and III malocclusions before and after bimaxillary orthognathic surgery. Before and after orthognathic surgery, 56 TMJs from 28 patients were studied. Following surgery, both class II and class III patients experienced changes in the anterior joint space, posterior joint space, condyle position, and condyle angle. The preliminary findings are promising for determining changes in condyle position and joint spaces that might guide oral and maxillofacial surgeons to address a debilitating clinical affliction.

Abstract

This study aimed at evaluating the mandibular condyle position changes before and after bimaxillary orthognathic surgery in class II and III malocclusion patients. CBCT scans from patients who underwent bimaxillary orthognathic surgery were analyzed: Le Fort I osteotomy and bilateral sagittal split osteotomy (BSSO). Both condyles were independently assessed for their largest anterior and posterior joint spaces, smallest medial joint spaces, and condyle angles concerning the transverse line. In the sagittal plane, the minimum size of the anterior and posterior joint spaces was measured. In the coronal plane, the smallest medial joint space was measured. The position of the condyle within the glenoid fossa was determined before and after surgery. A total of 56 TMJs from 28 patients were studied. Following orthognathic surgery, the anterior and posterior space in class II increased. Postoperatively, the anterior joint space in class III decreased. In 42.85% of malocclusion class II patients and 57.14% of malocclusion class III patients, the pre-and post-surgical position of the condyle changed, the condyle was anteriorly positioned (42.85%) in class II patients and centrically positioned (71.4%) in class III patients. Significant changes in the joint space, condylar position, and condyle angle were found in the class II and class III subjects.

Assessment of the Morphology and Degenerative Changes in the Temporomandibular Joint Using CBCT according to the Orthodontic Approach: A Scoping Review

BACKGROUND

Available knowledge about disorders of temporomandibular joint structures and their association with orthodontic variables are still lacking.

OBJECTIVES

This article is aimed at to identifying studies and presenting current information on the relationship between morphology diversity and the occurrence of degenerative changes in structures of the temporomandibular joint (TMJ) assessed by cone-beam computed tomography (CBCT) in the context of craniofacial morphology and malocclusion. Search Methods. The review was conducted by analyzing the PubMed (including Medline), Cochrane Library, Web of Science, and Scopus electronic databases up to November 2021 using two different comprehensive search strategies based on keywords as well as additional manual searches. Eligibility Criteria. Selection of the literature was carried out according to the PRISMA-ScR checklist. Methodological quality of the selected studies was evaluated using JBI Critical Appraisal Tool.

RESULTS

The electronic databases search revealed 3331 records. After applying the eligibility criteria and JBI assessment, a total of 33 studies were extracted and selected to the study. The review was divided into 4 parts, in which the following correlations were assessed in terms of orthodontic variables: TMJ degenerative changes, joint space and condylar position, condylar shape, TMJ articular eminence, and fossa.

CONCLUSIONS

Skeletal and dental class II malocclusion with a retrognathic mandible, a hypodivergent skeletal pattern with a steep mandibular plane, and significant lateral mandibular displacement can be risk factors for developing radiographically detectable degenerative changes. Patients with skeletal and dental class III malocclusion as well as a hyperdivergent skeletal pattern may be at greater risk of TMD occurrence compared with other groups. Further studies are necessary to clarify the relationship between the position of the condylar processes and the presence of degenerative changes in the temporomandibular joints among orthodontic patients.

Comprehensive 3D analysis of condylar morphology in adults with different skeletal patterns - a cross-sectional study

Background

The correlation between individuals’ condylar morphology and their skeletal pattern is of great interest for treatment strategies ranging from orthodontic orthopaedics to orthognathic surgery. The objective of the present study was to investigate this relationship three-dimensionally.

Methods

A total of 111 adult patients (mean age = 27.0 ± 10.2 years) who underwent head computed tomography or cone beam computed tomography scans were included. Based on these data, 3D models of the skull and the condyles were calculated. The craniofacial skeleton was evaluated (1) transversally regarding skeletal symmetry (menton deviation), (2) sagittally regarding skeletal classes (Wits appraisal) and vertically regarding the inclination of the jaws (maxillomandibular plane angle). The condylar morphology was assessed (a) linearly by the condylar width, height and depth; (b) angularly by the antero-posterior and medio-lateral condylar inclination; and (c) volumetrically by the ratio of the condylar volume/mandibular volume (C/Mand).

Results

(1) Transversal: Asymmetric patients showed significantly higher discrepancies in the volumetric ratio C/Mand on the deviation and non-deviation side compared to symmetric patients. (2) Sagittal: Class III subjects demonstrated longer, more voluminous condyles with higher antero-posterior and medio-lateral inclination angles compared to Class II participants. (3) Vertical: Hyperdivergent subjects had smaller condyles with higher antero-posterior inclination angles than those of hypodivergent subjects. No interactions of skeletal class and vertical relationships regarding condylar morphology were observed.

Conclusions

This study demonstrates a clear correlation between pronounced skeletal patterns and condylar morphology in an adult population. The description of radiographic condyle characteristics in relation to the craniofacial morphology improves orthodontic treatment planning and could be helpful in the diagnosis of temporomandibular joint pathologies.