Spatial analysis of mandibular condyles in patients with temporomandibular disorders and normal controls using cone beam computed tomography

Digital Condylar Parameter Assessment Using Cadiax® 2 and Modjaw®

Background: The main aim of this research was to assess the reliability of two systems designed specifically for condylar movement recording using condylar slope and Bennett angle information. The objectives were to evaluate the validity of two subsequent null hypotheses: (1) there is no significant difference between the measurements of condylar slope and Bennett angle taken at T0 (initial) and T1 (after one week) using the same equipment; (2) there is no notable difference in the values of the condylar slope and Bennett angle measurements obtained using Modjaw and Cadiax 2. Methods: An observational, descriptive, and prospective study was conducted with a selected group of 25 individuals (13 females and 12 males) aged between 22 and 27. Results: The results of Cadiax 2 and Modjaw showed excellent measurement repeatability for both parameters, with intraclass correlation coefficients (ICC) above 0.90, indicating excellent reliability between T0 and T1, both at 3 mm and 5 mm of displacement. Modjaw had an overall average value relatively higher than Cadiax 2, even though Modjaw's condylar slope at 5mm had a significantly lower average value (37.4 ± 6.31) with an interval of 24.5-48.1, which was lower than Cadiax 2 (48.4 ± 10.6) with an interval of 30.5-68.5. Regarding the primary aim, it can be stated that both Modjaw and Cadiax 2 demonstrated excellent repeatability on their own, demonstrating robust reliability since there was no discernible difference between the T0 and T1 measurements. On the contrary, analyses of the two devices' measured values for the secondary aim showed a considerable difference. Conclusions: Even though each device is reliable on its own, the absolute values that are obtained are different. Technological differences between the systems may account for these variations.

Positional and dimensional TMJ characteristics in different temporomandibular disorders: A cross-sectional comparative study

OBJECTIVE

To investigate the morphological and positional temporomandibular joint (TMJ) characteristics of different temporomandibular disorders (TMDs).

METHODS

One hundred forty-three TMD patients were divided into three groups: Group 1: Myalgia (M), Group 2: Disc displacement with reduction (DDWR), and Group 3: Disc displacement without reduction (DDWOR). Three-dimensional positional and dimensional parameters of the TMJ, including mandibular fossa, condyle, and TMJ spaces were evaluated using cone beam computed tomography (CBCT). The significance level was p < 0.05.

RESULTS

Mandibular condyles were significantly positioned in more vertical, posterior, and medial directions, with the reduced condylar width in the DD groups (p < 0.001). Anterior joint space was significantly higher in the DDWR group than the myalgia group; the superior joint spaces were more reduced in DD groups than the myalgia group.

CONCLUSION

Patients diagnosed with disc displacement showed significantly different condylar positions and joint spaces compared to the myalgia group in a skeletally comparable sample.

Modifications of the articular eminence inclination in association with the loss of occlusal support in the molar area. A cone-beam computed tomography study

The articular eminence (AE) is part of the temporal component of the temporomandibular joint (TMJ). The inclination of the AE (AEI) has an important role in TMJ biodynamics, influencing the path of movement of the disc-condyle complex. Although AEI values might change due to tooth loss, little is known about what effect could have the loss of occlusal support in the molar area on AE morphology. AEI was measured on cone-beam computed tomography (CBCT) images of 41 patients (82 TMJs) with or without occlusal support in the molar region. The patients included in this study were divided into four groups: (1) patients with maintained occlusal support in the molar areas on both sides (right and left side) (MM); (2) patients with loss of occlusal support in the molar areas on both sides (right and left side) (LL); (3) patients with loss of occlusal support in the molar area only on the right side, but with maintained occlusal support on the left molar area (LM); (4) patients with loss of occlusal support in the molar area only on the left side, but with maintained occlusal support in the right molar area (ML). AEI values were higher in the TMJs on the side with maintained occlusal support in the molar area (M) than the AEI values measured in TMJs from the side with loss of occlusal support in the molar area (L). AEI values on the right side were higher in the MM patients in comparison to the AEI values on the right side of LL patients. The loss of occlusal support in the molar areas changes the mandibular biodynamics, which might be reflected in the morphological changes at the AE level, where it might cause flattening of the articular slope predominantly on the right side.

Association Between Articular Eminence Structure and Joint Spaces in Temporomandibular Joints with Anterior Disc Displacement

BACKGROUND AND AIMS

The association among the joint spaces, articular eminence morphology, and disc displacement is not well documented in the literature. This study aims to evaluate and compare the joint spaces and the articular eminence structure (eminence height [Eh] and inclination [Ei]) using cone-beam computed tomography (CBCT) of temporomandibular joints (TMJs) with anterior disc displacements and joints with normal disc position.

METHODS

The study groups consisted of 75 TMJs of 39 patients. The disc status of TMJs was diagnosed with magnetic resonance imaging, and the measurements were performed on CBCT. Three groups, that is, normal disc position (NDP) group, anterior disc displacement with reduction (ADDWR) group, and anterior disc displacement without reduction (ADDWoR) group, were established. Anterior, superior, posterior joint spaces (AJS, SJS, and PJS, respectively), articular Eh, and articular Ei were measured. Statistical Package for the Social Sciences version 22 was used for statistical analysis. Shapiro-Wilk test was used to check the normality of data. Intergroup comparisons of categorical variables were assessed with Fisher-Freeman-Halton test. For comparison of continuous variables parameters, Mann-Whitney U test and Kruskal-Wallis test were used. Statistical significance level was determined as P < 0.05.

RESULTS

Significant differences were not found in intergroup comparisons for PJS. However, the difference between groups was found to be significant for AJS, SJS, Eh, and Ei. Intergroup comparisons were performed for these parameters. No significant difference was found between the NDP group and the ADDWR group for AJS, SJS, Eh, and Eİ. The mean AJS, SJS, Eh, and Ei values in ADDWoR were found to be significantly lower compared to the corresponding values in both NDP and ADDWR groups.

CONCLUSION

Decreased AJS and SJS when TMJ is evaluated with CBCT may be an indicator of ADDWoR. Authors suggest that narrowed articular Ei and reduced articular Eh can be one of the predisposing factors for anterior disc displacement.

Age and Gender-related Morphometric Assessment and Degenerative Changes of Temporomandibular Joint in Symptomatic Subjects and Controls using Cone Beam Computed Tomography (CBCT): A Comparative Analysis

BACKGROUND

The temporomandibular joint diseases have been associated with various predisposing factors. Joint spaces, articular eminence height and inclination, and the shapes of the condylar and glenoid fossa have all been shown to vary in temporomandibular joint diseases (TMD) patients. Advanced imaging techniques like cone beam computed tomography (CBCT) have been employed to estimate these parameters.

AIMS AND OBJECTIVES

The aim of the current study was to investigate the condylar morphology, condylar and glenoid fossa shapes, and assessment of joint spaces, such as anterior, posterior, superior, lateral, and medial spaces, through CBCT slices in coronal and sagittal planes and compare them between the control group and TMD group.

MATERIALS AND METHODS

A cross-sectional study was planned where 80 joints in 40 patients were assessed for the above parameters; group I consisted of healthy patients, and group II included those with temporomandibular joint diseases (TMDs). The articular eminence height and inclination were assessed on the midsagittal section. The condylar changes and shapes of the glenoid fossa and condyles, as well as the joint spaces, were assessed on the selected coronal and sagittal sections.

RESULTS

The condylar fossa had a triangular shape in the TMJ group and an oval shape in the control group. The results were highly significant (P = 0.000**). A highly significant difference in morphological parameters, such as AJS, PJS, SJS, MJS, LJS, articular eminence height, and inclination, was found between the two groups (P = 0.000**). The association of morphological parameters, such as AJS, PJS, SJS, MJS, LJS, and articular eminence height and inclination were compared with condylar and glenoid fossa shapes, where the association of superior joint space and articular eminence inclination was observed. A highly significant difference was noted between the two groups with regard to all the parameters with P=0.00*.

CONCLUSION

The articular eminence inclination, as well as the superior joint space, were found to be associated with the glenoid and condyle fossa shapes in the TMJ group. These observations would, therefore, help in the early diagnosis of temporomandibular joint diseases.

Assessment of bony changes in temporomandibular joint in patients using cone beam computed tomography - a cross sectional study

BACKGROUND AND AIM

The aim of this study is to evaluate the changes in the temporomandibular joint (TMJ) in patients with temporomandibular disorder (TMD) and the relationship between age, sex, and types of TMJ change using Cone Beam Computed Tomography (CBCT).

METHODS AND MATERIAL

CBCT records of 200 patients (123 women and 67 men) were retrieved and assessed. Right and left TMJs were evaluated separately, resulting in a total of 400 TMJs. The images were analyzed using On demand 3D Application The radiographic findings were classified as erosion, proliferative changes mainly, including flattening and osteophytes of the condyle, sclerosis, Ely cyst, hypoplasia and hyperplasia of the condyles, ankylosis, and joint cavity. Data analysis was performed using descriptive statistics, paired T-tests, and repeated measure ANOVA (Analysis of Variance) in SPSS Software.

RESULTS

The most prevalent types of condylar bony changes observed was osteophyte (63.5%) followed by flattening of the articular surface (42%), erosion (40%), ankylosis (10%) and sclerosis (10%). 7.5% of joints showed hyperplastic condyles but only 2% showed hypoplasia. The least prevalent change observed was Ely Cyst (1%). Osteophyte was the most prevalent change observed in all age groups and both sexes except for men aged 31 ~ 50, where flattening was more frequent. A statistically significant difference was found between sex and prevalence of erosion in the age group of 10 ~ 30 (P = 0.001); as well as between sex and condylar hyperplasia in the same age group.

CONCLUSION

Based on the findings of this research, the prevalence of bony changes of TMJ from highest to lowest is as follows: osteophyte, flattening of the articular surface, erosion, ankylosis, sclerosis, hyperplastic condyles, hypoplastic condyles and Ely Cyst. CBCT is an accurate 3 dimensional imaging modality for assessment of TMJ bony structures.

Condylar Positional Changes in Skeletal Class II and Class III Malocclusions after Bimaxillary Orthognathic Surgery

Orthognathic surgery is indicated to modify the position of the maxillomandibular structure; changes in the mandibular position after osteotomy can be related to changes in the position of the mandibular condyle in the articular fossa. The aim of this study was to determine changes produced in the mandibular condyle 6 months after orthognathic surgery. A cross-sectional study was conducted that included subjects who had undergone bimaxillary orthognathic surgery to treat dentofacial deformity of Angle class II (group CII) or Angle class III (group CIII). Standardized images were taken using cone-beam computed tomography 21 days before surgery and 6 months after surgery; measurement scales were used to identify the condylar position and its relations with the anterior, superior, and posterior joint spaces. The results were analyzed using the Shapiro-Wilk and Student's t-tests, while considering a value of p < 0.05 as indicating a significant difference. Fifty-two joints from 26 patients, with an average age of 27.9 years (±10.81), were analyzed. All subjects in both group CII and group CIII showed a significant change in the anterior, superior, and posterior joint spaces. However, postoperative changes in the position of the condyle in the articular fossa were not significant in the anteroposterior analysis. We conclude that orthognathic surgery causes changes in the sagittal position of the mandibular condyle in subjects with mandibular retrognathism and prognathism.

Dimensional and positional temporomandibular joint osseous characteristics in normodivergent facial patterns with and without temporomandibular disorders

OBJECTIVE

This study evaluated the dimensional and positional osseous temporomandibular joint features in normodivergent facial patterns with and without temporomandibular disorders.

METHODS

A total of 165 adult patients were divided into two groups: group 1 (n = 79 patients; 158 joints): temporomandibular disorders patients and group 2 (n = 86 patients; 172 joints): non-temporomandibular disorders patients. Three-dimensional positional and dimensional temporomandibular joint characteristics, including glenoid fossa, mandibular condyles, and joint spaces, were assessed by cone beam computed tomography.

RESULTS

The glenoid fossa positions in the three orthogonal planes and height showed statistical significance between the two studied groups. The temporomandibular disorders patients showed higher horizontal and vertical condyle inclinations while anteroposterior inclination was less, and the condyle was positioned more superior, anterior, and lateral in the glenoid fossa. The condyle width and length showed no significance between the two groups, while condyle height was smaller in temporomandibular disorders patients. Anterior and medial joint spaces increased while the superior and posterior joint spaces reduced in temporomandibular disorders patients.

CONCLUSION

There were significant differences between the patients with and without temporomandibular joint disorders in terms of mandibular fossa positions and height as well as condylar positions and inclinations in horizontal and vertical planes together with reduced condylar height and reduced posterior and superior joint spaces in the temporomandibular disorders patients.

CLINICAL RELEVANCE

The temporomandibular disorder is a multifactorial disorder in which one of these factors is the dimensional and positional characteristics of the temporomandibular joints; including or excluding this factor requires a comprehensive three-dimensional investigation of patients with TMD compared to the normal group under the condition that the facial pattern is average as a confounding factor.

Research progress in effect of chewing-side preference on temporomandibular joint and its relationship with temporo-mandibular disorders

Chewing-side preference is one of the risk factors for temporomandibular disorders (TMD), and people with chewing-side preference is more prone to have short and displaced condyles, increased articular eminence inclination and glenoid fossa depth. The proportion of TMD patients with chewing-side preference is often higher than that of the normal subjects. Clinical studies have shown a strong correlation between chewing-side preference and TMD symptoms and signs; and animal studies have shown that chewing-side preference can affect the growth, development, damage and repair of the mandible. After long-term unilateral mastication, changes in the stress within the joint cause the imbalance of temporomandibular joint (TMJ) structural reconstruction, the transformation and even destruction of the fiber structure of masticatory muscle, resulting in uncoordinated movement of bilateral muscles. The joint neurogenic diseases caused by the increase of neuropeptide substance P and calcitonin-gene-related-peptide (CGRP) released locally by TMJ may be the mechanism of TMD. This article reviews the research progress of the influence of chewing-side preference on the structure of TMJ, the relationship between chewing-side preference and TMD, and the related mechanisms.

Positional Features of the Mandibular Condyle in Patients with Facial Asymmetry

OBJECTIVE

To describe the position of the mandibular condyle, the size of the joint spaces and the condylar angulation in patients with facial asymmetry (FA), and to classify these results according to the type of FA and compare them with a reference group without FA. Materials and Methods/Patients: An observational, cross-sectional, descriptive study using computed tomography (CT) was conducted on a sample of 133 patients with a clinical diagnosis of FA derived from the following entities: hemimandibular elongation (HE) (n = 61), hemimandibular hyperplasia (HH) (n = 11), condylar hyperplasia in its hybrid form (HF) (n = 19), asymmetric mandibular prognathism (AMP) (n = 25), glenoid fossa asymmetry (GFA) (n = 9) and functional laterognathism (FL) (n = 8). Likewise, a group of 20 patients without clinical or tomographic characteristics of FA was taken and their complete cone beam tomography (CBCT) scans were analyzed. The quantified variables were joint spaces (anterior, middle and posterior), angle of the condylar axis and condylar position. All measurements were performed using the free, open-source Horos software.

RESULTS

Most of the subjects without FA had a right middle condylar position (55%), while in the patients with FA the anterior condylar position predominated. On the left side, the most frequent condylar position was anterior, including the group without FA, except in the HH group. Considering the measurements of the anterior, middle and posterior joint space (mm) on the right side (anterior JS: 1.9 mm, middle JS: 2 mm and posterior JS: 2.8 mm) and on the left side (anterior JS: 2.7 mm, middle JS: 2.1 mm and posterior JS: 2.6 mm) of the subjects without FA, compared to those with FA, the latter presented smaller distances in all diagnoses and only for the right posterior JS (1.9 mm) in HH, was not significant. The condylar axis of the AF group showed significant differences with smaller angles for the left side in those diagnosed with HE (65.4°) and HH (56.5°) compared to those without AF (70.4°).

CONCLUSIONS

The condylar position of patients with FA tends to be anterior, both on the right and left sides, while for cases without FA it is middle and anterior, respectively. Patients with FA have smaller joint spaces (mm) compared to patients without FA, with the exception of HH for the right posterior JS.

Cone beam computed tomography in the assessment of TMJ deformity in children with JIA: repeatability of a novel scoring system

BACKGROUND

The temporomandibular joint (TMJ) is frequently involved in juvenile idiopathic arthritis (JIA). Diagnostic imaging is necessary to correctly diagnose and evaluate TMJ involvement, however, hitherto little has been published on the accuracy of the applied scoring systems and measurements. The present study aims to investigate the precision of 20 imaging features and five measurements based on cone beam computed tomography (CBCT).

METHODS

Imaging and clinical data from 84 participants in the Norwegian study on juvenile idiopathic arthritis, the NorJIA study, were collected. Altogether 20 imaging features and five measurements were evaluated independently by three experienced radiologists for intra- and interobserver agreement. Agreement of categorical variables was assessed by Fleiss', Cohen's simple or weighted Kappa as appropriate. Agreement of continuous variables was assessed with 95% limits of agreement as advised by Bland and Altman.

RESULTS

"Overall impression of TMJ deformity" showed almost perfect intraobserver agreement with a kappa coefficient of 0.81 (95% CI 0.69-0.92), and substantial interobserver agreement (Fleiss' kappa 0.70 (0.61-0.78)). Moreover, both "flattening" and "irregularities" of the eminence/fossa and condyle performed well, with intra- and interobserver agreements of 0.66-0.82 and 0.55-0.76, respectively. "Reduced condylar volume" and "continuity" of the fossa/eminence had moderate intra- and interobserver Kappa values, whereas continuity of the condyle had Kappa values above 0.55. Measurements of distances and angles had limits of agreement of more than 15% of the sample mean.

CONCLUSIONS

We propose a CBCT-based scoring system of nine precise imaging features suggestive of TMJ deformity in JIA. Their clinical validity must be tested.

Evaluation of the temporomandibular joint morphology and condylar position with cone-beam computerized tomography in patients with internal derangement

OBJECTIVES

To evaluate the relationship between internal derangement and morphological features of the temporomandibular joint by comparing joint morphology between patients with ID and control patients.

METHODS

The current study prospectively is evaluated the cone-beam computed images of 106 ID patients and 122 patients with asymptomatic joints; recorded angular and linear measurements. The relationships between these measurements and ID are investigated; the differences between the two groups using paired t tests.

RESULTS

There were significant differences in the values of articular slope and the condyle height/glenoid fossa depth (CH/GFD) ratio between patients in the ID and control groups (p < 0.05). There was also a relationship between these parameters and the gender of patients with ID. The condylar position was posterior in the ID group.

CONCLUSION

Posteriorly and superiorly located condyles with an increased CH/GFD ratio, condyles located eccentrically, and a steeper posterior slope may be risk factors for ID.

Dimensional and Positional Characteristics of the Temporomandibular Joint of Skeletal Class II Malocclusion with and without Temporomandibular Disorders

AIM

This study sought to evaluate dimensional and positional temporomandibular joint (TMJ) features in three-dimensions in skeletal class II malocclusion with and without temporomandibular disorders (TMDs).

MATERIALS AND METHODS

A total of 91 (182 joints) adult patients were divided into the following two groups: (1) Group I - TMD (n = 56; 112 joints) and (2) group II - non-TMD (n = 35; 70 joints). Dimensional and positional TMJ characteristics including glenoid fossae, mandibular condyles, and joint spaces were assessed using cone-beam computed tomography (CBCT).

RESULTS

The mandibular fossa in the TMD group was significantly more lateral than in the non-TMD group, and the mandibular fossa anterior wall inclination to the horizontal plane showed a significantly more vertically inclined wall in the TMD group compared to the non-TMD group. Significantly vertical mandibular condylar changes in the form of less vertical inclination, more vertical position, and lower vertical dimension (height) in addition to more upward position within the joint space were found. The TMD group showed significantly decreased superior and posterior joint spaces in addition to significantly increased medial joint spaces.

CONCLUSION

Patients with TMDs are associated with laterally positioned mandibular fossa with the more vertically inclined anterior wall. They are characterized by vertical mandibular condylar changes in the form of less vertical inclination, more vertical position, and lower vertical dimension (height) in addition to more upward positioning within the joint space is accompanied by a decrease in superior and posterior and an increase in medial joint spaces.

CLINICAL SIGNIFICANCE

The TMJ characteristics of skeletal class II make it more susceptible to TMDs and any orthodontic and/or surgical interventions in a direction possibly change these characteristics are to be considered.

Three-Dimensional Assessment of the Temporomandibular Joint Changes Following Reversed Twin Block Therapy of Patients With Skeletal Class III Malocclusion in Conjunction With the Photobiomodulation Therapy: A Randomized Controlled Clinical Trial

BACKGROUND

Despite the positive effect of the photobiomodulation therapy (PBMT) application on animals, the primary role of this technique on the human condyle is still unclear. Several experimental reports have shown the efficacy of PBMT in inducing cellular changes in the temporomandibular joint (TMJ) region during functional treatment of patients with skeletal deformities. Still, the lack of information about its effects on human condyles requires further studies.

OBJECTIVES

This study aimed to evaluate the effect of PBMT on the TMJ components following Class III treatment with the reversed twin block (RTB) appliance in growing patients.  Materials and Method: Forty children (12 females, 28 males) between the age of nine and eleven years with skeletal Class III were assigned randomly to the RTB group with photobiomodulation (RTB+PBMT) or the control group (RTB). The PBMT was applied to the TMJ region using an 808-nm wavelength Ga-Al-As semiconductor laser device with 5 Joules/cm2 energydensity on days 1, 3, 7, and 14 of the first month. Afterwards, the irradiation was conducted every 15 days until the end of the treatment. Cone-beam computerized tomography (CBCT) images were taken before (T1) treatment and following the end of treatment (T2) to assess TMJ and skeletal changes.

RESULTS

Condylar volume was significantly increased in the RTB group only by a mean of 287.97 mm3 (p<0.001). The significantly backward and upward condylar movement was observed in the RTB and RTB+PBMT groups (superior joint space (SJS): 0.26 mm, 0.15 mm; posterior joint space (PJS): 0.42mm, 0.11mm, respectively). The RTB group showed the most remarkable changes. Significant improvement of the sagittal maxilla-mandibular relationship was greater in the RTB+PBMT group compared to the RTB group (p=0.02).

CONCLUSION

There were no considerable differences in the condylar position after Class III treatment between the RTB and the RTB+PBMT groups. But a difference in the condylar volume was noticed between the two group.

Relationship between horizontal condylar angle and radiographically detectable morphological changes of the condyle in asymptomatic and symptomatic patients with TMD

Background

The relationship between horizontal condylar angle (HCA) measurements and radiographically detectable morphological changes of the condyle in patients with temporomandibular disorder (TMD) is an area of controversy in dentistry.

Aim

This study sought to determine the effect of the HCA on radiographically morphological changes in the condyles of asymptomatic and symptomatic patients with TMD.

Material & methods

Cone beam computed tomography (CBCT) scans were used of patients with 146 temporomandibular joints (TMJ) with and without symptoms of TMD. The reconstructed axial plane was adjusted to depict the condyle in maximum width. The HCA was established and measured as the angle formed between the condylar long axis intersecting with the coronal plane. Each condyle long axial was determined independently from the other joint by two oral and maxillofacial radiologists. The average of the readings from the two examiners was used for statistical analysis.

Results

Based on the clinical symptoms, the mean of the HCA in the symptomatic joint was 27.69°, which was slightly greater than the angle measured in asymptomatic patients of 25.6°; however, this was not a statistical difference. No significant differences existed in the mean of the HCA between the joint with and without radiographic arthritic findings in both groups. In both groups, none of the arthritic findings manifested in the affected joint that had influenced the HCA.

Conclusion

The HCA was increased in the symptomatic group but had no direct influence on joint's morphological changes in the asymptomatic and symptomatic patients.

Cone-beam computed tomographic assessment of the inclination of the articular eminence in patients with temporomandibular disorders and chewing side preference

Background

Chewing side preference (CSP) has been proposed as one etiology of temporomandibular disorders (TMDs) as it can induce the structural changes of the temporomandibular joint. But its association with the inclination of the articular eminence (IAE) is unknown. This study aimed to compare IAE between patients with CSP and without CSP.

Methods

Cone-beam computed tomography images of 90 patients with TMD (mean age of 45.6 years, 69 with CSP, 21 without CSP) and 20 participants without TMD and CSP (mean age of 41.3 years) were measured to compare IAE and depth of the glenoid fossa (DGF)

Results

IAE and DGF showed a positive correlation among all the participants. Compared with the participants without TMD and CSP, the TMD patients without CSP presented a similar IAE but with a significantly higher value of DGF (p < 0.05); in contrast, the TMD patients with CSP presented a significantly greater IAE and DGF (p < 0.05). No bilateral differences in IAE and DGF were observed in all the participants. Except the male patients with CSP had a deeper fossa than did the female, no differences in IAE and DGF according to gender were observed.

Conclusions

TMD patients with CSP seem to have a deep glenoid fossa with steep eminence which might be considered one characteristic imaging feature.

The Short-Term Effect of Active Skeletonized Sutural Distractor Appliance on Temporomandibular Joint Morphology of Class III Malocclusion Subjects

Objectives  The purpose of this study was to evaluate the short-term effect of active skeletonized sutural distractor (ASSD) appliance on temporomandibular joint morphology of class III malocclusion subjects.

Materials and Methods  This was a prospective interventional study. Cone-beam computerized tomography (CBCT) images of 22 patients were taken before and after treatment by using Planmeca Promax 3D CBCT machine version 2.9.2 (Planmeca OY Helsinki, Finland). The condylar width, height, length, roof of glenoid fossa thickness, and all joint spaces were measured. The condylar position was determined based on Pullinger and Hollander formula. The condylar shape was determined as per Kinzinger et al. The condylar volume was calculated by using Mimics software (Materialize, Belgium).

Statistical Analysis  Data analysis was performed by using SPSS software version 24. Wilcoxon paired signed-rank test was used to compare the difference in temporomandibular joint morphology and condylar volume between pre- and post-treatment measurements. Chi-square test was used to compare the condylar position and shape.

Results  The superior ( p = 0.000 on the right side, p = 0.005 on the left side) and posterior joint spaces ( p = 0.000 on both sides) were decreased after the treatment, respectively. The condyles were rotated upward and backward, thereby increasing the anterior joint spaces ( p = 0.000 on both sides) after the treatment. The condylar volume increases after treatment, but no significant differences were observed ( p = 0.903 on the right side, p = 0.062 on the left side).

Conclusion  The significant changes were observed in joint spaces. The condyles were more anteriorly placed before treatment. Condylar position and shape alter in response to ASSD treatment. The condylar volume did not show any significant change.

Is There an Association between Temporomandibular Disorders and Articular Eminence Inclination? A Systematic Review

(1) Background: In order to determine the correlation between the inclination of articular eminence (AEI) and the development of temporomandibular disorders (TMDs), a systematic review was performed. (2) Methods: A systematic literature research was conducted between 1946 and January 2020, based on the following electronic databases: PubMed, Cochrane Library, Embase, Medline, Scope, SciELO, and Lilacs. Observational studies, analytical case-control studies, and cohort studies written in English were identified. The articles were selected and analyzed by two authors independently. The PICO format was used to analyze the studies and the Newcastle-Ottawa Scale (NOS) was used to verify the quality of the evidence. (3) Results: Sixteen articles were included in this review, ten case-control studies and six cohort studies. Eight articles (50%) established a positive relation between AEI and TMDs and eight (50%) did not. The scientific quality was medium-low, mainly influenced by the exposure to the risk of bias and the lack of clinical methods with adequate consistency and sensitivity on the diagnosis of TMDs. (4) Conclusions: It is controversial to establish a causal relationship between the TMDs and the AEI in the field of stomatology, due to limited and inconclusive evidence. However, it is suggested that the AEI defined by some specific methods may be associated with some special pathological stages of TMDs. High-quality prospective studies are required to draw any definitive conclusions.

Condyle modeling stability, craniofacial asymmetry and ACTN3 genotypes: Contribution to TMD prevalence in a cohort of dentofacial deformities

Craniofacial asymmetry, mandibular condylar modeling and temporomandibular joint disorders are common comorbidities of skeletally disproportionate malocclusions, but etiology of occurrence together is poorly understood. We compared asymmetry, condyle modeling stability and temporomandibular health in a cohort of 128 patients having orthodontics and orthognathic surgery to correct dentofacial deformity malocclusions. We also compared ACTN3 and ENPP1 genotypes for association to clinical conditions. Pre-surgical posterior-anterior cephalometric and panometric radiographic analyses; jaw pain and function questionnaire and clinical examination of TMD; and SNP-genotype analysis from saliva samples were compared to assess interrelationships. Almost half had asymmetries in need of surgical correction, which could be subdivided into four distinct morphological patterns. Asymmetric condyle modeling between sides was significantly greater in craniofacial asymmetry, but most commonly had an unanticipated pattern. Often, longer or larger condyles occurred on the shorter mandibular ramus side. Subjects with longer ramus but dimensionally smaller condyles were more likely to have self-reported TMD symptoms (p = 0.023) and significantly greater clinical diagnosis of TMD (p = 0 .000001), with masticatory myalgia most prominent. Genotyping found two significant genotype associations for ACTN3 rs1671064 (Q523R missense) p = 0.02; rs678397 (intronic SNP) p = 0.04 and one significant allele association rs1815739 (R577X nonsense) p = 0.00. Skeletal asymmetry, unusual condyle modeling and TMD are common and interrelated components of many dentofacial deformities. Imbalanced musculoskeletal functional adaptations and genetic or epigenetic influences contribute to the etiology, and require further investigation.

Concha bullosa, nasal septal deviation, and their impacts on maxillary sinus volume among Emirati people: A cone-beam computed tomography study

Purpose

To determine the prevalence of concha bullosa (CB) and nasal septal deviation (NSD) and their impact on maxillary sinus volume (MSV).

Materials and Methods

Cone-beam computed tomographic (CBCT) images of 106 Emirati people were used in this study. The direction and angle of septal deviation were calculated. The presence of CB, which could be unilateral, contralateral, or bilateral in relation to the direction of NSD, was also recorded. MSV was measured using reconstructed Digital Imaging and Communication in Medicine images on Dolphin 3D imaging software version 11.8 premium (Dolphin Imaging, Chatsworth, CA, USA). P values <0.05 were considered to indicate statistical significance.

Results

CB was detected in 37.7% of the sample; 20.7% of the sample showed single unilateral CB and 16.6% had single bilateral CB. NSD was seen in 74.5% of the sample. In the participants with CB, 45.5% showed mild deviation, 34.4% showed moderate deviation, and only 12.5% showed severe septal deviation. CB, but not NSD, was associated with significantly higher MSV on the affected side (P=0.001).

Conclusion

Although NSD was observed in more than two-thirds of the sample and CB was present in more than one-third of the sample, only CB had a significant impact on MSV.

Evaluation of condyle position in patients with Angle Class I, II, and III malocclusion using cone-beam computed tomography panoramic reconstructions

OBJECTIVES

This study was performed to compare the positions of the right and left condyles between male and female patients with different Angle malocclusions using cone-beam computed tomography (CBCT) panoramic reconstructions.

METHODS

The CBCT images of 60 patients (age of 18-37 years) were retrospectively evaluated. The patients were divided according to their Angle malocclusion classifications (Angle Classes I, II, and III). The condyle-to-eminence, condyle-to-fossa, and condyle-to-meatus distances were measured digitally using i-CAT software.

RESULTS

The left and right condyle-to-fossa distances were the most variable parameters among the Angle classes. The right condyle-to-eminence and right condyle-to-fossa distances were significantly different among the classes. Male patients seemed to have a greater condyle-to-fossa distance on the right side in both the Class I and III groups. The mean distance from the condyle to eminence, condyle to fossa, and condyle to meatus on the right side was the greatest in the Angle Class II group.

CONCLUSIONS

In all three types of malocclusion (Angle Classes I, II, and III), the condyles on both the right and left sides were not exactly symmetric or centrally located within the glenoid fossa. This work emphasizes the differences in the condyle position between male and female patients. Furthermore, the symmetry and centricity of the condyles are not dependent on the patient's sex or type of malocclusion.

Imaging modalities for temporomandibular joint disorders: an update

The diagnosis and management of temporomandibular disorders (TMD) require both clinical and imaging examinations of the temporomandibular joint (TMJ). A variety of modalities can be used to image the TMJ, including magnetic resonance imaging (MRI), computed tomography (CT), cone beam CT, ultrasonography, conventional radiography. The present review outlines the indications of the most frequently used imaging techniques in TMD diagnosis. Because of the anatomic complexity of the TMJ, imaging can be difficult. Choosing the proper imaging technique is essential. Conventional radiography, nowadays, is of limited interest. The use of flat plane films for TMJ pathology is not sufficient, because this joint requires three dimensional imaging views. Osseous changes are better visualized with CT and cone beam CT. Cone beam CT provides high-resolution multiplanar reconstruction of the TMJ, with a low radiation dose, without superimposition of the bony structures. MRI is a noninvasive technique, considered to be the gold standard in imaging the soft tissue components of the TMJ. MRI is used to evaluate the articular disc in terms of location and morphology. Moreover, the early signs of TMD and the presence of joint effusion can be determined. High-resolution ultrasonography is a noninvasive, dynamic, inexpensive imaging technique, which can be useful in diagnosing TMJ disc displacements. The diagnostic value of high-resolution ultrasonography is strictly dependent on the examiner's skills and on the equipment used.