Cone-beam tomography assessment of the condylar position in asymptomatic and symptomatic young individuals

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.

Measurement and analysis of condylar morphology and thickness of the roof of the glenoid fossa in patients with unilateral second molar scissor bite

Objective The objective of this study was to measure and analyze the joint space, condylar morphology, and thickness of the roof of the glenoid fossa (RGF) in patients with unilateral second molar scissor bite using cone beam CT (CBCT). Methods A total of 80 patients were included in this study. Forty patients with a normal posterior occlusal relationship, who attended the Department of Orthodontics at the First Hospital of Shanxi Medical University from December 2021 to August 2023, were selected as the control group. The experimental group consisted of 40 patients with unilateral second molar scissor bite during the same period. All patients underwent CBCT scanning, and the resulting images were analyzed using the NNT viewer software in multiplanar reconstruction (MPR). Axial, coronal, and sagittal adjustments were made for each patient. Results In the control group, the right and left joint spaces (PS, SS, AS), the height of the upper part of the condyle, and the depth of the glenoid fossa did not show statistically significant differences (P > 0.05). When comparing bilateral condylar morphology and joint space in the experimental group, it was found that the posterior joint space on the scissor bite side was greater than that on the normal occlusion side, while the anterior joint space on the scissor bite side was smaller than that on the normal occlusal side. Additionally, the height of the upper condyle and the depth of the glenoid fossa on the scissor bite side were greater than that on the normal occlusal side, with statistically significant differences (P < 0.05). However, there were no statistically significant differences in SS, internal and external joint diameter, as well as anterior and posterior diameters (P > 0.05). The comparison of the minimum thickness of the roof of the glenoid fossa in both the sagittal and coronal directions between the patients in the experimental group and the control group showed no statistically significant difference (P > 0.05). Furthermore, the asymmetry index of the supracondylar height in the control group was significantly smaller than that in the experimental group, displaying a statistically significant difference (P < 0.05). The differences in the asymmetry indices of the anterior and posterior diameters of the condyle, as well as the inner and outer diameters, were not statistically significant (P > 0.05). When analyzing the position of the condyle in the sagittal direction of the glenoid fossa in the patients of the control group, it was observed that the majority were in the anterior and medial positions, with only 10% and 5% being in the posterior position. However, the analysis of the condyle position in the sagittal direction of the glenoid fossa in the experimental group revealed statistically significant differences (P < 0.05), with the condyle position on the scissor bite side being more anterior. Conclusion Unilateral second molar scissor bite can result in anterior displacement of the condyle, greater height of the condyle superiorly as well as the depth of the glenoid fossa.

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.

Correlation of clinical manifestations and condylar morphology of patients with temporomandibular degenerative joint diseases

OBJECTIVE

To study the correlation between condylar morphology and clinical manifestations in patients with degenerative joint disease (DJD) of the temporomandibular joint (TMJ).

METHODS

A total of 175 joints of 131 patients with DJD were included. Data on patients' basic information and symptoms were collected and analyzed. Condylar morphology was evaluated using cone beam computed tomography (CBCT). The correlation between the condylar morphology and clinical manifestations was analyzed.

RESULTS

The prevalence of joint noises, clicks, and crepitus was 93/175 (53%), 73/175 (42%), and 20/175 (11%), respectively. Condylar anteroposterior diameter and condylar height were correlated with pain. There was a correlation between the shape of the condyle in the sagittal plane and joint noise.

CONCLUSION

Condylar morphology and clinical features of DJD were correlated to some extent.

Influence of botulinum toxin A in pain perception and condyle-fossa relationship after the management of temporomandibular dysfunction: a randomized controlled clinical trial

OBJECTIVES

To investigate the pain perception (PP) and condyle-fossa relationship (CFR) after botulinum toxin A (BoNTA) injection in the masseter muscles of painful muscular temporomandibular dysfunction (TMD) patients.

MATERIALS AND METHODS

Fourteen women (aged 29.7 ± 5.4 years) diagnosed with myogenic TMD were randomized in the BoNTA-treated group (TG) and control group (CG). TG masseter muscles (n = 7) were bilaterally injected with 30 U. The CG (n = 7) were injected with saline injections. Condyle-fossa relationship (CFR) spaces were measured in sagittal (SP) and frontal planes (FP) of images of cone-beam computed tomography (CBCT) done before (T0) and after 30 days' interventions (T1). Visual analogue scale (VAS) measured the patients' TMD pain perception (PP). Data were compared by generalized linear models considering the results over time (α = .05).

RESULTS

There were no statistical differences in CFR in the SP or FP for TG and CG over time (p ˃ .05), except for frontal lateral space CFR (p < .05). In both groups, the condyle was positioned medially after interventions. Frontal lateral space increased in TG for both, left and right sides, over time (p < .05), as well as PP decreased over time (p < .05) for TG and CG.

CONCLUSIONS

The results depicted that there was no significant association with BoNTA injection in TMD masseter muscles in PP and CFR, except considering the frontal lateral space of CFR.

CLINICAL RELEVANCE

BoNTA injection in the masseter muscles may not promote clinically significant shifts in the condyle-fossa relationships of muscular TMD patients.

Developing a universal and reliable temporomandibular joint reference system for quantifying morphological and positional changes

OBJECTIVES

This study aimed to provide a universal and reliable reference system quantifying temporomandibular joint (TMJ) morphological and positional changes.

METHODS

Large field-of-view (FOV) cone-beam computed tomography (CBCT) images (20 TMJs) from 10 preorthognathic surgery patients and limited FOV CBCT images (40 TMJs) from 20 splint therapy-treated patients with temporomandibular disorders were collected. TMJ-specific reference system including a TMJ horizontal reference plane (TMJHP) and a local coordinate system (TMJCS) was constructed with landmarks on cranial base. Its application for TMJ measurements and its spatial relationship to common Frankfort horizontal plane (FHP) and maxillofacial coordinate system (MFCS) were evaluated.

RESULTS

Five relevant landmarks were selected to optimally construct TMJ-specific reference system. General parallelism between TMJHP and FHP was demonstrated by minimal angular and constant distance deviation (1.714 ± 0.811º; 2.925 ± 0.817 mm). Additionally, tiny axial orientational deviations (0.181 ± 6.805º) suggested TMJCS rivaled MFCS. Moreover, small deviations in orientations and distances (1.232 ± 0.609º; 0.310 ± 0.202 mm) indicated considerable reliability for TMJCS construction, with intraclass correlation coefficients (ICCs) ranging from 0.999 to 1.000. Lastly, slight discrepancies in translations and rotations revealed high reliability for condylar positional and morphological measurements (ICC, 0.918-0.999).

LIMITATIONS

TMJ-specific reference system was merely tested in two representative FOVs.

CONCLUSIONS

This study provides a universal and reliable reference system for TMJ assessment that is applicable to both limited and large FOV CBCT. It would improve comparability among diverse studies and enable comprehensive evaluations of TMJ positional and morphological changes during TMJ-related treatment follow-up such as splint therapy and disease progression.

Centric relation-A biological perspective of a technical concept

BACKGROUND

Few terms and concepts have been so extensively debated in dentistry as the words 'centric relation' (CR). Debates involve its biological, diagnostic and therapeutic usefulness.

METHODS

A review of the literature on the current concepts on CR as a diagnostic or therapeutic aid in dentistry was provided. Clinical trials assessing the superiority of one CR recording method over the others to identify patients with temporomandibular disorders (diagnostic use) or to manage patients with prosthodontic or orthodontic needs (therapeutic use) were tentatively included.

RESULTS

Due to the absence of literature addressing either of the above targets, a comprehensive overview was provided. The diagnostic use of CR as a reference position to identify the correct position of the temporomandibular joint condyle within the glenoid fossa is not supported and lacks anatomical support. From a therapeutic standpoint, the use of CR can be pragmatically useful in prosthodontics as a maxillo-mandibular reference position when occlusal re-organization is warranted and/or when the position of maximum intercuspation is no longer available.

CONCLUSIONS

The derived occlusal goals from a diagnostic misuse of CR are generally the result of circular reasoning, that is a technique is based on the recording of a certain condylar position that is believed to be 'ideal' and the treatment is considered successful when such position is shown by the specific instrument that was manufactured for that purpose. The term 'Centric Relation' might be replaced with the term 'Maxillo-Mandibular Utility Position'.

Assessment of condylar anatomy and degenerative changes in temporomandibular joint disorders - A scoping review

Temporomandibular disorders (TMDs) are a group of conditions that cause pain and dysfunction in the temporomandibular joint (TMJ) and muscles that control mandibular movement. In most cases, the etiology is unclear and is considered multifactorial. Recent research suggests that some forms of TMD could be associated with specific TMJ morphological characteristics. This study aims to provide a review of the reported anatomical and degenerative morphological condylar characteristics of subjects with a clinical diagnosis of TMD as described with the use of CBCT imaging, as well as the detection of potential predisposing anatomical factors. This review was developed and reported in accordance with the PRISMA-ScR Checklist. A comprehensive search was performed in five databases. Reports were screened by two independent reviewers based on preselected inclusion and exclusion criteria. 45 studies were included in this review. The most frequently reported degenerative changes associated with TMD were condylar surface erosion, flattening, osteophytes, and sclerosis. Anatomical characteristics included a small condylar size and a posterior position of the condylar head in the TMJ. The anterosuperior area of the condylar head appears to be the most frequently affected. More studies are required to determine potential specific predisposing anatomical characteristics.

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.

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.

Centric relation: A needed reference position

PURPOSE

Centric Relation (CR) is a universally recognized term and an acceptable reference position with a long history of success. The problem is that there is little consensus as to its definition or the method of recording it, and this has created an uprising to abolish it.

METHODS

A review of pertinent literature related to its definition, method of recording, anatomic considerations and long-standing principles was conducted.

RESULTS

CR is an established term but there are valid concerns over its definition and method of recording. There is consensus on using it as a restorative position in a patient in need of full arch reconstruction and there is no substantive clinical research to contradict this. If a clinician decides to use a different position, it should have a different name.

CONCLUSIONS

CR is a reproducible reference position that can be utilized for diagnostic and restorative dental procedures with substantial scientific evidence to support that premise. There are numerous well documented techniques, all of which are intermaxillary, that can replicate the position. There is little scientific evidence to support a premise as to where the exact position of the condyle should be in relation to the fossa. This article is protected by copyright. All rights reserved.

The Relationship Between Centric Occlusion and The Maximal Intercuspal Position and Their Use as Treatment Positions for Complete Mouth Rehabilitation: Best Evidence Consensus Statement

PURPOSE

The purpose of this Best Evidence Consensus Statement was to evaluate the existing literature relative to two focus questions: How often does centric occlusion coincide with maximal intercuspal position in dentate and partially dentate populations?; and should centric occlusion or maximal intercuspal positions be equivalent for dentate and partially dentate patients undergoing complete mouth rehabilitation?

MATERIALS AND METHODS

Keywords used in the initial search were: intercuspal position, centric occlusion, centric relation, maximal intercuspal position, prosthodontic rehabilitation, and occlusion. The search was then limited to Systematic Reviews, Randomized Controlled Studies, Meta-analyses and Clinical Trials.

RESULTS

The initial search strategy related to the selected search terms resulted in more than 15,000 articles. When the subsequent search was limited to Systematic Reviews, Randomized Controlled Studies, and Meta-Analysis and Clinical Trials, 313 articles were selected for further analysis.

CONCLUSIONS

Review of the literature reveals that most dentate and partially dentate patients do not have coincident centric occlusion and maximal intercuspal position. There is support for coincidence between centric occlusion and maximal intercuspal position as the preferred occlusal relationship in complete mouth rehabilitations. The literature does not report conclusive evidence of adverse prosthodontic outcomes with complete rehabilitations in centric occlusion or maximal intercuspal position in a healthy population. However, there is support for an association between centric occlusion-maximal intercuspal position discrepancies and occlusal instability as well as temporomandibular joint disorders. Hence, it is concluded that partially and completely dentate patients requiring complete mouth rehabilitation should be restored in centric occlusion.

Angle's Classification-A Prosthodontic Consideration: Best Evidence Consensus Statement

PURPOSE

This Best Evidence Consensus Statement evaluated the existing Angle's classification clinical literature to determine if the Angle's classification as historically determined in maximum intercuspal position (MIP) with hand held casts is coincident with the centric occlusion (CO) determined Angle's classification. In addition, it explored the value of using Angle's classification for edentulous patients MATERIALS AND METHODS: The search strategy was related to the focus questions and limited to Meta-analyses, Systematic Reviews (SR), Randomized Controlled Trials (RCT) and Clinical Trials. Searches were completed using the term Angle's classification and Boolean Modifiers (AND) with the key terms: dental occlusion, dental occlusion centric, centric occlusion, centric relation, maximal intercuspation, MIP, intercuspal position, and edentulous patient, retrognathia, determination, and prognathia. Additional related articles were culled from the reference lists in the articles found in the PubMed searches.

RESULTS

The search identified 494 articles related to the selected terminology. Titles were reviewed and selected if related to the focus questions for further review. Seven papers could be identified that addressed the specifics of the questions.

CONCLUSIONS

There is evidence that the Angle's classification for many patients will change when recorded in CO compared to the historical MIP determination/definition. A different Angle's classification recorded in CO is potentially a significant diagnostic finding for patients needing complete mouth rehabilitation. The current definitions of Angle's Classification are not useful in the management of edentulous patients.

Evaluation of the condylar position in younger and older adults with or without temporomandibular symptoms by using cone beam computed tomography

STATEMENT OF PROBLEM

Recent studies in young adults have questioned the influence of discrepancies between central and maximal intercuspal positions in temporomandibular disorders (TMDs). However, whether this finding was because this type of etiologic agent requires time for the development of changes in the condylar position is unclear.

PURPOSE

The purpose of this clinical study was to use cone beam computed tomography (CBCT) to evaluate the presence or absence of discrepancies between the centric relation (CR) and maximum intercuspation (MI) in younger and older adults in populations with or without TMDs.

MATERIAL AND METHODS

The sample was composed of 80 volunteers, 40 younger individuals aged 18 to 25 years (27 women and 13 men), half with and half without TMD symptoms, and 40 older participants aged 35 to 50 years (30 women and 10 men), half with and half without TMD symptoms. The TMD symptoms were diagnosed by using the diagnostic (standard) criteria for TMD research (RDC/TMD). Two CBCT scans were performed on each participant, one in MI and another in CR. Measurements of the joint space were performed in coronal and sagittal cuts of the temporomandibular joints, and the collected data were statistically analyzed by using the Mann-Whitney U test (α=.05).

RESULTS

No significant differences were found when the CR and MI positions and the presence or absence of TMD symptoms were compared in the younger and older groups. However, when the younger and older groups were compared, significant differences were found in all measures used in this study.

CONCLUSIONS

The condyle and mandibular fossa do not seem to be influenced by the CR or MI positions or by the presence or absence of TMD symptoms, but age seems to lead to a quantitative increase in the relationship between these structures.

Oral rehabilitation following successful TMD treatment with condylar position changes: A case report

BACKGROUND

A 31-year-old woman with crowns, fixed partial prostheses, and dental restorations complained of recurrent pain in the left and right temporomandibular joints during the last 2 years.

CLINICAL PRESENTATION

The symptoms of temporomandibular disorder (TMD) resolved successfully after a 3-month-long treatment with a repositioning splint. Pre- and post-operative cone-beam computed tomography revealed slight changes in the condylar position after splint use. Minimally invasive oral rehabilitation guided by digital design was performed to maintain the acquired stable position. The status of the restorations was good, and the TMD symptoms did not relapse during the 3-year follow-up.

CONCLUSION

This case report demonstrates the importance of a stable adapted condylar position after extensive prosthodontic treatment.

Estimated functional space of centric condyle positions in temporomandibular joints of asymptomatic individuals using MRI

Magnetic resonance imaging (MRI) studies on centric condyle positions lack 3D comparisons of guided and unguided methods, which are used for accomplishing centric relation reference positions. The purpose of this study was to describe the space, in which mandibular condyles are placed in vivo by dental intercuspation, Dawson’s bimanual manipulation, and neuromuscular position. Twenty asymptomatic individuals aged 23 to 37 years underwent separate bite registrations using bimanual manipulation and the unguided neuromuscular technique. Subsequent 3-Tesla MRI scans of both temporomandibular joints yielded 3D data of the most superior condylar points at maximum intercuspation and both centric relation positions. We found concentric condyle positions in maximum intercuspation but considerable variation of condyle position after bimanual manipulation and neuromuscular technique. Their 95% predictive confidence ellipses overlapped substantially and created a space of reference positions. Its smallest volume averaged 2 mm³ for a minimal convex hull (95% confidence interval 1.1–3.2) and 3.5 mm³ for a minimal ellipsoid hull (95% confidence interval 1.8–5.4). Visualized in vivo by MRI, condyle positions at bimanual manipulation and neuromuscular position were not predictable and showed substantial variation in asymptomatic subjects. Clinicians should be aware of the functional space and its effect on dental intercuspation.

Evaluation of condyle-fossa relationships in adolescents with various skeletal patterns using cone-beam computed tomography

OBJECTIVES

To evaluate the condyle-fossa relationship in adolescents with various skeletal patterns using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

CBCT images obtained in 120 adolescent patients were used for this study. The patients were divided into 3 groups according to 3 criteria: (1) age (early, middle, and late adolescence); (2) facial height ratio or Jarabak quotient (hyperdivergent, normodivergent, and hypodivergent); and (3) ANB classification (Class I, Class II, and Class III). Temporomandibular joint space (TMJS: AS, anterior space; SS, superior space; PS, posterior space; MS, medial space; LS, lateral space), width and depth of the condyle (MLT, mediolateral thickness; APT, anteroposterior thickness), articular slope (ArS) and vertical height of the fossa (VHF) were measured and compared using CBCT.

RESULTS

Differences in condyle-fossa relationships were not significantly different between male and female adolescents, but were significantly different (P < .05) between left and right sides. The mean values showed no statistical differences according to age and skeletal pattern. Most measurements in the sagittal view showed that SS was the greatest, and the mean ratio of AS to SS to PS was 1.00 to 1.27 to 1.19, respectively. The mean values of coronal MS and LS were not significantly different.

CONCLUSIONS

There were almost no statistical differences in the TMJS in adolescents across various factors except between left and right sides.

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

OBJECTIVES

The aim of the study is to investigate the condylar position and its relation to articular eminence and axial condylar angle in temporomandibular joint disorder (TMD) patients and in normal controls using cone beam computed tomography (CBCT).

MATERIALS AND METHODS

CBCT temporomandibular joint (TMJ) images of 70 participants (38 males and 32 females, mean age 26.4 years) were analyzed. They were divided into control group (including 35 subjects) and study group (including 35 subjects). Linear measurements of joint space and condyle determined the condylar position of each TMJ. Articular eminence height and inclination were also measured with axial condylar angle to determine its relation to condylar position. Independent and paired sample t-test was applied to compare between the groups and TMJ sides of the same group at significance level of 0.05.

RESULTS

Statistical significant differences were found between males and females of both groups regarding superior joint space (SJS), lateral joint space, A-P, and M-L condyle distance (P < 0.05). SJS, medial joint space (MJS), and eminence angle were greater (P < 0.01) in male's joints with TMD with flatter axial condylar angle (P < 0.05), when compared with normal TMJ counterpart. Females TMJs showed significantly higher values of MJS of affected side when compared with normal counterpart with flatter axial condylar angle (P < 0.05).

CONCLUSION

Superior and MJS parameters were the ones that showed significant differences between affected and nonaffected joints. The mean axial condylar angle was smaller in joints with abnormal TMJ. This indicates that the condyles of the affected joints may rotate inward.

CBCT and MRT imaging in patients clinically diagnosed with temporomandibular joint arthralgia

OBJECTIVES

To compare cone beam computed tomography (CBCT) and magnetic resonance tomography (MRT) in patients with temporomandibular joint (TMJ) arthralgia in respect of the evaluation of bony structures, and to correlate joint space distances measured in CBCT with the morphology and the position of the disc visualized in MRT.

MATERIALS & METHODS

26 temporomandibular joints (TMJs) in 13 patients clinically diagnosed with TMJ arthralgia were examined by both CBCT and MRT. All images were evaluated by use of a form. The results were compared in regard of conformability of the diagnoses of osseous structures established by each imaging method. Anterior, superior and posterior joint space distances measured in CBCT-images were related to disc morphology and position visualized in MRT.

RESULTS

Conformability of CBCT and MRT in the evaluation of bony TMJ structures ranged from 69.3 to 96.6 %. Osseous alterations such as erosions, osteophytes and cysts detected by CBCT could partly not be discerned by MRT. The correlation of joint space distances with disc morphology (biconcave or not biconcave) was not statistically significant. The correlation of joint space distances and disc position was statistically significant only for the superior joint distance.

CONCLUSION

CBCT outclasses MRT in the visualization of osseous alterations, which are diacritic in the differentiation of simple arthralgia from osteoarthritis. Therefore, CBCT imaging is appropriate in patients clinically diagnosed with TMJ arthralgia.Superior joint space distance not being the highest joint space in sagittal CBCT indicates an anterior disc displacement.For the visualization of structural changes or displacement of the disc frequently associated with osseous changes, MRT is the optimal tool. Thus, the combination of the two imaging methods allows a comprehensive diagnosis in TMJ arthralgia patients.

The association between condylar bone changes revealed in cone beam computed tomography and clinical dysfunction index in patients with or without temporomandibular joint disorders

OBJECTIVE

The aim of the present study was to compare cone beam computed tomography (CBCT) findings pertinent to patients with temporomandibular disorder (TMD) and patients without TMD (non-TMD), as well as to investigate the correlation between these findings and the clinical dysfunction index (Di).

STUDY DESIGN

In this cross-sectional study, CBCT images of temporomandibular joints (TMJs) were evaluated for condylar bone changes in 84 patients with TMD. The patients were assigned a score using Helkimo's clinical Di, ranging from 1 to 25, and were thereafter subdivided into 3 groups based on the degree of Helkimo's Di. CBCT and clinical records of sex- and age-matched non-TMD patients were used as the control group.

RESULTS

There was a significant difference in the prevalence of all types of bone changes between TMD and non-TMD groups (all P < .05), except for loose joint bodies. Furthermore, there was a significant correlation between the total amount of bone change and the Helkimo Di score (P < .001).

CONCLUSION

Evaluation of CBCT images in the present study revealed significant differences between TMD and non-TMD condyles. There was also a significant relationship between the Helkimo clinical Di and the total amount of condylar bone change in patients with TMD.

Cone-Beam Computed Tomographic Assessment of Mandibular Condylar Position in Patients with Temporomandibular Joint Dysfunction and in Healthy Subjects

Statement of the Problem. The clinical significance of condyle-fossa relationships in the temporomandibular joint is a matter of controversy. Different studies have evaluated whether the position of the condyle is a predictor of the presence of temporomandibular disorder. Purpose. The purpose of the present study was to investigate the condylar position according to gender in patients with temporomandibular disorder (TMD) and healthy controls using cone-beam computed tomography. Materials and Methods. CBCT of sixty temporomandibular joints in thirty patients with TMD and sixty joints of thirty subjects without TMJ disorder was evaluated in this study. The condylar position was assessed on the CBCT images. The data were analyzed using Pearson chi-square test. Results. No statistically significant differences were found regarding the condylar position between symptomatic and asymptomatic groups. Posterior condylar position was more frequently observed in women and anterior condylar position was more prevalent in men in the symptomatic group. However, no significant differences in condylar position were found in asymptomatic subjects according to gender. Conclusion. This study showed no apparent association between condylar positioning and clinical findings in TMD patients.