Associations between the articular eminence inclination and condylar bone changes, condylar movements, and condyle and fossa shapes

Evaluation of condyle-fossa relationships in skeletal Class I malocclusion with variable degrees of deep overbite and open bite

OBJECTIVE

To compare the temporomandibular joint (TMJ) position and shape between skeletal Class I subjects with different degrees of deep overbite or open bite and unaffected peers.

METHODS

Cone beam computed tomography (CBCT) images of 90 participants, equally divided into deep bite, open bite, and control groups (DBG, OBG, and CG, respectively), were analyzed. The DBG and OBG were further subdivided into three subgroups based on the severity. Linear and angular measurements were used to determine the positional and morphological characteristics of the TMJ.

RESULTS

DBG showed significantly larger superior joint space, anterior inclination of the condyle, and articular eminence inclination than CG and OBG. The severity of deep bite and open bite significantly influenced the TMJ position and morphology.

CONCLUSION

In severe deep overbite and open bite cases, there were considerable alterations in TMJ components, most likely as a result of functional demands.

Anatomical consideration of ultrasonography-guided intraoral injection for temporal tendinitis

Temporal tendinitis is characterized by acute inflammation often resulting from mechanical stress, such as repetitive jaw movements associated with jaw opening and closing and teeth clenching. Treatment for temporal tendinitis typically involves the administration of local anesthetic or corticosteroid injections. However, the complex anatomical structure of the coronoid process, to which the temporalis tendon attaches, located deep within the zygomatic arch, poses challenges for accurate injections. In this study, we aimed to establish guidelines for the safe and effective treatment of temporal tendinitis by using intraoral ultrasonography (US) to identify the anatomical structures surrounding the temporalis tendon and coronoid process. US was performed using an intraoral transducer on 58 volunteers without temporomandibular joint disease. The procedure involved placing the transducer below the occlusal plane of the maxillary second molar. Measurements were taken for the horizontal distance from the anterior border of the coronoid process, observed at the midpoint (MP) of the US images, and the depth of the coronoid process and temporalis muscle from the oral mucosa. The anterior border of the coronoid process was visualized on all US images and classified into three observed patterns at the MP: type A (anterior to the MP, 56.2%), type B (at the MP, 16.1%), and type C (posterior to the MP, 27.7%). The temporalis muscle was located at a mean depth of 3.12 ± 0.68 mm from the oral mucosa. The maxillary second molar is an intraoral landmark for visualizing the anterior border of the coronoid process. The new location information obtained using intraoral US could help identify the safest and most effective injection sites for the treatment of temporal tendinitis.

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.

Evaluation of morphological and morphometric characteristics of the temporomandibular joint in children with different skeletal models in the sagittal and vertical direction

OBJECTIVE

This study aims to evaluate differences in the morphological and morphometric features of hard tissue components of the temporomandibular joint (TMJ) in the cone beam computed tomography (CBCT) images of children with different skeletal models in the sagittal and vertical plane.

METHODS

Condyle dimensions, horizontal condylar angle, the distance of the condyle center to the midsagittal plane, condyle position, eminence height, eminence inclination, condyle, and fossa shape and symmetry were evaluated in CBCT images in 190 TMJs in 95 pediatric patients. Patients were classified as Class 1-2-3 in the sagittal direction, as hypodivergent, normodivergent, and hyperdivergent in the vertical direction. Children were divided into 10-13 and 14-17 age groups.

RESULTS

The left superior joint space in children with a different skeletal model in the sagittal plane was lower and found to be statistically significant in Class 3 children (p < 0.05). A statistically significant difference was found lower in the left articular eminence inclination and height in Class 3 children (p < 0.05). The most common oval fossa form was seen in Classes 2-3 children (p < 0.05). It was determined that the anterior joint space was lower in hyperdivergent children and the condyle was located more anteriorly. The mediolateral length of the condyle and the height of the articular eminence were positively correlated with age.

CONCLUSIONS

The results revealed that the difference in skeletal models seen in sagittal and vertical planes in children may cause morphological and morphometric changes in the hard tissue components of TMJ.

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.

Oval Type of Human Mandibular Condyle in Panoramic Radiographs of a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction

Mandibular condyle is a prominent structure in the mandible, which forms the temporomandibular joint. An oval-shaped condyle is considered to be present with a normal temporomandibular joint and any morphological variation of the condyle is assumed to be pathologic in temporomandibular disorders. The aim of the study was to find out the prevalence of oval shaped mandibular condyle among orthopantomogram radiographs of patients visiting the tertiary care centre.

Methods

A descriptive cross-sectional study was performed among 752 condyles visiting a tertiary care center from November 29, 2021 to April 1, 2022. The ethical approval was taken from the Institutional Review Committee (Reference number: 184 (6-11) 078/079) before conducting the study. Convenience sampling was done. The radiographs were first examined and the observed morphological type of mandibular condyle was noted. Data analysis was done using Statistical Package for the Social Sciences version 22.0. Point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data.

Results

The prevalence of oval shaped mandibular condyles out of 752 condyles was 416 (55.32%) (51.77-58.87 at 95% Confidence Interval). The oval-shaped condyle on the right side was 205 (54.52%) and on the left side was 211 (56.12%).

Conclusions

The prevalence of oval shaped condyles among patients in this study was similar to the studies done in similar settings.

Keywords

condyle; mandible; Nepal; X-ray.

Temporomandibular Joint Osseous Morphology of Class I and Class II Malocclusions in the Normal Skeletal Pattern: A Cone-Beam Computed Tomography Study

(1) Background—The aim of the present study was to evaluate the correlation between the temporomandibular joint (TMJ) osseous morphology of normal skeletal pattern individuals with different dental malocclusions by using cone-beam computed tomography (CBCT). (2) Methods—The CBCT images of bilateral TMJs in 67 subjects with skeletal class I and average mandibular angle (26 males and 41 females, age range 20–49 years) were evaluated in this study. The subjects were divided into class I, class II division 1, and class II division 2 according to the molar relationship and retroclination of the maxillary incisors. Angular and linear measurements of TMJ were evaluated and the differences between the groups were statistically analyzed. (3) Results—Intragroup comparisons showed statistical differences for articular eminence inclination, the width of the glenoid fossa, the ratio of the width of the glenoid fossa to the depth of the glenoid fossa, the condylar angle, and the intercondylar angle between the malocclusion groups. The measurements of the glenoid fossa shape showed no significant difference between the left and right sides. Females showed more differences in the morphological parameters of TMJ between the three malocclusion groups than the males. (4) Conclusion—The present study revealed differences in the TMJ osseous morphology between dental class I and class II malocclusions in the normal skeletal pattern.

The influence of mandibular condyle morphology on TMJ anterior dislocations

OBJECTIVES

The present study was designed to investigate the correlation between the bony morphology of the mandibular condyle and the occurrence of temporomandibular joint (TMJ) idiopathic anterior dislocation.

STUDY DESIGN

A comparative retrospective study was conducted among 14 patients presenting idiopathic anterior dislocations (study group) and 15 patients who did not suffer from any TMJ disorders (control group). All patients underwent a multidetector computed tomography scan demonstrating the full extent of their joints. The scans of 58 joints were reconstructed and analyzed by tools available in Dolphine3 software. Mandibular condyle size and volume were measured, and its shape was characterized.

RESULTS

Shape, width, length, height, and volume of the mandibular condyles did not differ statistically between the study and control groups.

CONCLUSION

Mandibular condyle morphology does not affect TMJ idiopathic anterior dislocation.

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.

Morphometric evaluation of the temporomandibular joint on cone-beam computed tomography

INTRODUCTION

Evaluation of the temporomandibular joint (TMJ) pathologies with cone-beam computed tomography (CBCT) provides essential information about the bone structures of the TMJ. It is important to know the normal reference range when defining these pathologies. The aim of this study is to examine the morphometric and morphologic analyses of the bone structures of TMJ on the CBCT images in detail according to age, gender, and joint side.

MATERIAL AND METHODS

A total of 35 parameters related to the condylar process, articular tubercle, mandibular fossa, ramus of mandible, and joint space were examined on the CBCT images. These parameters were compared with the joint sides and gender, and correlated with age.

RESULTS

Thirty-five parameters were evaluated. A statistically significant difference was found between genders in 22 parameters and joint sides in 6 parameters. When the correlation of parameters with age was examined; it was found that there was a very weak positive relationship in nine parameters, a weak positive relationship in one parameter, and a very weak relationship in the negative direction in two parameters.

CONCLUSION

In this study, the condylar process, articular tubercle, mandibular fossa, ramus of mandible, and joint spaces, which are usually examined separately in the literature, were examined, and the normal reference range was determined for all these parameters. We think that these normal reference ranges will be useful for researchers interested in TMJ pathologies.

A radiological evaluation of the effects of edentulousness on the temporomandibular joint

BACKGROUND

The articular eminence of the temporomandibular joint is an anatomical structure exposed to functional loads resulting from masticatory forces. Tooth loss may change the biomechanics of the masticator system, and the articular eminence can be affected by this change.

OBJECTIVE

The aim of this study is to examine the relationship between the edentulousness and the articular eminence inclination of the temporomandibular joint.

METHODS

The articular eminence inclination was measured in panoramic radiographs in the right and left temporomandibular joint on a total of 100 patients (50 dentate and 50 edentulous). The articular eminence inclination of dentate and edentulous patients was compared, as well as the influence of gender and duration of edentulousness.

RESULTS

The mean articular eminence inclination value in the dentate group (42.6 ± 4.3⁰ ) was higher than that of the edentulous group (35.1 ± 4.7⁰ , P < .001). Although there was no significant difference between males and females in the dentate group with regard to articular eminence inclination (42.0 ± 4.7⁰ and 42.9 ± 4.1⁰ , respectively, P = .373), in the edentulous group, males had higher values as compared to females (37.1 ± 4.7⁰ and 34.2 ± 4.5⁰ , respectively, P = .003). Finally, the duration of edentulousness and the degrees of articular eminence inclination values did not show positive correlations (P = .782).

CONCLUSION

According to the results of this study, we found that edentulous patients had lower articular eminence inclination than dentate patients, and it was more prominent in female than male patients.

Cone beam computed tomographic assessment of mandibular condyle in Kennedy class I patients

OBJECTIVES

The aim of this study was to assess the dimensional and volumetric changes in the mandibular condyle in Kennedy class I patients versus completely dentate patients by cone beam computed tomography (CBCT) to estimate the effect of loss of posterior teeth on the mandibular condyle.

PATIENTS AND METHODS

This study was performed on one hundred patients requesting CBCT scans: fifty Kennedy class I patients and fifty fully dentate controls. Condyle dimensions mesio-distal, cranio-caudal and antero-posterior as well as condyle volume were measured in both the groups.

RESULTS

Kennedy class I patients showed statistically significant higher mean condyle width but lower mean condyle height than the control group. No statistically significant difference was found between the study group and the control group regarding condyle AP dimension. There was no statistically significant difference between condyle volumes in the two groups.

CONCLUSION

Loss of posterior teeth is accompanied by significant decrease in condyle height and increase in condyle width with no change in the total condyle volume or antero-posterior dimensions.

The relationship of articular eminence and mandibular fossa morphology to facial profile and gender determined by cone beam computed tomography

OBJECTIVE

The aim of this study was to evaluate the relationship of the morphology of the articular eminence and mandibular fossa to facial profile and sex by using cone beam computed tomography (CBCT) images.

STUDY DESIGN

CBCT examinations of 76 patients were conducted, and the patients were classified according to facial profile as dolichocephalic, mesocephalic, or brachycephalic. The inclination and height of the articular eminence and the inclination of the mandibular fossa of 152 temporomandibular joints were measured. Comparisons between these measurements and facial profile and gender were performed by 2-way analysis of variance with Tukey's post hoc test. Significance was established at α = 0.05.

RESULTS

Males with brachycephaly presented significantly greater values of eminence inclination compared with those with other facial types and greater values than patients with dolichocephaly for the measurements of eminence height and inclination of the fossa posterior wall (P ≤ .05). Females with brachycephaly presented significantly greater eminence height values compared with those with other facial profiles (P ≤ .05). No significant differences were observed between males and females.

CONCLUSIONS

The morphology of the articular eminence and the mandibular fossa is associated with facial profile, with males with brachycephaly showing greater inclination of the eminence and mandibular fossa. Articular eminence height in brachycephaly was greater in both sexes.

Clinical guidelines for dental cone-beam computed tomography

Dental cone-beam computed tomography (CBCT) received regulatory approval in Japan in 2000 and has been widely used since being approved for coverage by the National Health Insurance system in 2012. This imaging technique allows dental practitioners to observe and diagnose lesions in the dental hard tissue in three dimensions (3D). When performing routine radiography, the examination must be justified, and optimal protection should be provided according to the ALARA (as low as reasonably achievable) principles laid down by the International Commission on Radiological Protection. Dental CBCT should be performed in such a way that the radiation exposure is minimized and the benefits to the patient are maximized. There is a growing demand for widespread access to cutting-edge health care through Japan's universal health insurance system. However, at the same time, people want our limited human, material, and financial resources to be used efficiently while providing safe health care at the least possible cost to society. Japan's aging population is expected to reach a peak in 2025, when most of the baby boomer generation will be aged 75 years or older. Comprehensive health care networks are needed to overcome these challenges. Against this background, we hope that this text will contribute to the nation's oral health by encouraging efficient use of dental CBCT.

Analysis of the correlation between dental arch and articular eminence morphology: a cone beam computed tomography study

OBJECTIVE

The aim of the study was to assess the correlation between the morphology of the dental arches (DAs) of patients with normal occlusion and of the articular eminence (AE) by using cone beam computed tomography (CBCT).

STUDY DESIGN

CBCT scans of 60 patients were evaluated in terms of height and inclinations (angles α, β, and δ) of the AE. DAs were classified according to their shapes (tapered, square, ovoid), and their perimeters, widths, and depths were measured. One-way analysis of variance, Pearson's correlation coefficients, and simple and multivariate linear regression models were used for the calculations.

RESULTS

The ovoid arch was the most predominant shape (n = 66/120). Inclination of the AE (angle β) had the greatest difference between DA shapes, with this angle usually being greater in the ovoid arch and smaller in the square arch (P < .05). The height of the AE presented greater correlation with DA measurements, with tapered arches having the most significant correlations (P < .05). DA depth had no influence on AE measurements (P > .05). The perimeter and width of the DAs had some influence (P < .05).

CONCLUSIONS

Correlations were found between the DA and AE morphologies. The correlations should be taken into consideration, although the results do not prove absolute association between the variables. Whenever possible, the morphologic features of DAs should be preserved to avoid possible changes in AE.

Differences in skeletal components of temporomandibular joint of an early medieval and contemporary Croatian population obtained by different methods

The temporomandibular joint (TMJ) is one of the most complex joints in the human body. The anatomical configuration of the TMJ allows for a large range of mandibular movements as well as transmission of masticatory forces and loads to the skull base. The measurements of the TMJ's anatomical structures and their interpretations contribute to the understanding of how pathological changes, tooth loss, and the type of diet (changing throughout human history) can affect biomechanical conditions of the masticatory system and the TMJ. The human TMJ and its constituent parts are still the subject of extensive investigation and comparisons of measurement methods are being made in order to determine the most precise and suitable measurement methods. The aim of this study has been to examine the morphology of skeletal components of TMJ of an early medieval population (EMP) in Croatia and to compare measured values with TMJ values of the contemporary Croatian population (CP) using various methods of measurement. The study was performed on 30 EMP specimens - human dry skulls, aged from 18 to 55 years, and 30 CP human dry skulls, aged from 18 to 65 years. Only fully preserved specimens (in measured areas) were included. The articular eminence (AE) inclination was measured in relation to the Frankfurt horizontal using two methods. Also, the AE height (glenoid fossa depth) and the length of the curved line - highest to the lowest point of the AE were measured. Measurements were performed on lateral skull photographs, panoramic radiographs and lateral cephalograms using VistaMetrix software on skull images. The results were statistically analyzed using SPSS statistical software. No statistically significant differences were obtained for AE parameters between the EMP and CP populations independent of age and gender. However, statistically significant (p<0.05) differences were revealed when comparing results of three different measuring methods. It could not be determined which of the used measurement methods is the most accurate due to the different results obtained as well as the presence of possible shortcomings and limitations of the various methods (measuring points are difficult to determine and/or they are not clearly observed in the investigated images to be precisely marked and measured; distortion and magnification of structures on radiographic images are present). Therefore, due to the limitations of this study, the obtained results could serve only as orienting information.