A Study to Assess the Temporomandibular Joint Variations in Digital Computed Tomography–A Cross-Sectional Study

International Journal of Dental Science and Innovative Research (IJDSIR) IJDSIR : Dental Publication Service Available Online at:www.ijdsir.com Volume – 8, Issue – 6, December – 2025, Page No. : 49 – 59 Corresponding Author: Dr. Abha Verma, ijdsir, Volume – 8 Issue - 6, Page No. : 49 - 59 Page49 ISSN: 2581-5989 PubMed - National Library of Medicine - ID: 101738774 A Study to Assess the Temporomandibular Joint Variations in Digital Computed Tomography–A Cross-Sectional Study 1Dr. Abha Verma, Postgraduate Student, Department of Oral Medicine and Radiology, Darshan Dental College and Hospital, Loyara, Udaipur, Rajasthan 2Dr. Saba Khan, Professor and HOD, Department of Oral Medicine and Radiology, Darshan Dental College and Hospital, Loyara, Udaipur, Rajasthan 3Dr. Tulika Sharma, Reader, Department of Oral Medicine and Radiology, Darshan Dental College and Hospital, Loyara, Udaipur, Rajasthan 4Dr. Nishita Gautam, Senior Lecturer, Department of Oral Medicine and Radiology, Darshan Dental College and Hospital, Loyara, Udaipur, Rajasthan 5Dr. Lipi Sisodia, Professor, Department of Oral Medicine and Radiology, Darshan Dental College and Hospital, Loyara, Udaipur, Rajasthan 6Dr. Shreya Khandhedia, Postgraduate Student, Department of Oral Medicine and Radiology, Darshan Dental College and Hospital, Loyara, Udaipur, Rajasthan Corresponding Author: Dr. Abha Verma, Postgraduate Student, Department of Oral Medicine and Radiology, Darshan Dental College and Hospital, Loyara, Udaipur, Rajasthan Citation of this Article: Dr. Abha Verma, Dr. Saba Khan, Dr. Tulika Sharma, Dr. Nishita Gautam, Dr. Lipi Sisodia, Dr. Shreya Khandhedia, “A Study to Assess the Temporomandibular Joint Variations in Digital Computed Tomography–A Cross-Sectional Study”, IJDSIRDecember – 2025, Volume – 8, Issue – 6, P. No. 49 – 59. Copyright: © 2025, Dr. Abha Verma, et al. This is an open access journal and article distributed under the terms of the creative common’s attribution non-commercial License. Which allows others to remix, tweak, and build upon the work non-commercially, as long as appropriate credit is given, and the new creations are licensed under the identical terms. Type of Publication: Original Research Article Conflicts of Interest: Nil Abstract Background: The temporomandibular joint (TMJ) is a complex synovial articulation facilitating mastication, phonation, and deglutition. Understanding TMJ morphology and morphometry is essential to differentiate physiological remodeling from pathological changes. Cone Beam Computed Tomography (CBCT) provides precise three-dimensional evaluation of osseous structures with minimal distortion and radiation exposure. Aim: This study aimed to assess ageand gender-related morphological and morphometric variations of the TMJ using CBCT in an Indian population, establishing normative reference data. Materials and Methods: A cross-sectional observational study was conducted on CBCT scans of participants divided into three age groups: 20–39, 40–59, and ≥60 Dr. Abha Verma, et al. International Journal of Dental Science and Innovative Research (IJDSIR) ©2025 IJDSIR, All Rights Reserved Page50 Page50 Page50 Page50 Page50 Page50 Page50 Page50 Page50 Page50 Page50 Page50 Page50 Page50 Page50 Page50 Page50 Page50 Page50 years. Morphological features—condylar flattening, cortical sclerosis, erosion, and osteophyte formation— were recorded. Morphometric measurements included condylar height, width, volume, and anterior, superior, and posterior joint spaces bilaterally. Data were analyzed using descriptive and inferential statistics. Pearson correlation assessed age-morphometry relationships, while intraand inter-observer reliability was evaluated using intraclass correlation coefficient (ICC). Results: Condylar flattening (23%) and sclerosis (17.3%) were the most common morphological changes. Condylar height, width, and volume decreased significantly with age (p < 0.05). Superior and posterior joint spaces narrowed with age, while anterior space remained stable. Condylar height showed the strongest negative correlation with age (r = –0.372, p < 0.001). Males had significantly larger condylar dimensions and fossa depth than females (p < 0.05), with no significant gender difference in joint space. Intraand inter-observer reliability was excellent (ICC > 0.90). Conclusion: TMJ morphology and morphometry vary with age and gender. CBCT provides reliable quantitative assessment, aiding in distinguishing adaptive remodeling from early pathology and offering essential normative data for clinical reference in diagnosis and treatment planning. Keywords: Temporomandibular joint, CBCT, Morphology, Morphometry, Age, Gender, Remodeling, Joint Space, Condylar Height. Introduction The temporomandibular joint (TMJ) is a complex synovial articulation connecting the mandibular condyles with the temporal bones, enabling mastication, deglutition, phonation, and facial expressions¹. Its intricate anatomy, including a biconcave articular disc, dual compartments, and synchronized bilateral movement, makes it susceptible to structural variations, degenerative changes, and functional disorders². Standardized diagnostic protocols, such as RDC/TMD and DC/TMD, integrate clinical and psychosocial assessments to improve reliability across populations3,4. However, clinical evaluation alone may fail to detect subtle osseous changes, joint space variations, or early degeneration5,6. Conventional two-dimensional imaging, including panoramic and lateral cephalometric radiographs, is limited by distortion and superimposition7,8. Digital CT and cone-beam CT (CBCT) provide high-resolution, three-dimensional visualization of condylar morphology, joint spaces, and articular eminence angulation with reproducible morphometric measurements9-11. TMJ morphology is influenced by age, sex, occlusal patterns, parafunctional habits, and genetics, with age-related condylar flattening, joint space narrowing, and cortical changes commonly observed12-15. Bilateral asymmetry, condylar shape variations, and altered joint spaces may reflect functional adaptation or predisposition to TMDs16,17. This cross-sectional study aimed to assess TMJ morphological variations and bony changes using digital CT. The objectives were to evaluate TMJ differences across age groups, compare right–left joint variations, assess gender-related differences, and determine the diagnostic efficacy of digital CT. The study documented condylar morphology, articular eminence angulation, glenoid fossa dimensions, joint space widths, and bilateral symmetry to establish normative reference data for clinical and research use18-24. Material and method This cross-sectional observational study evaluated morphological variations and bony changes of the temporomandibular joint (TMJ) using digital computed Dr. Abha Verma, et al. International Journal of Dental Science and Innovative Research (IJDSIR) ©2025 IJDSIR, All Rights Reserved Page51 Page51 Page51 Page51 Page51 Page51 Page51 Page51 Page51 Page51 Page51 Page51 Page51 Page51 Page51 Page51 Page51 Page51 Page51 tomography (CT). Ethical approval was obtained from the Institutional Ethics Committee, and all scans were anonymized. Only archival diagnostic CT images were used, ensuring no additional radiation exposure. Study Population A total of 300 adult CT scans (≥18 years) of both genders were included. Scans were selected based on: adequate image quality, complete bilateral TMJ visualization, standardized imaging parameters, and absence of systemic bone disorders. Exclusion criteria included motion artifacts, poor contrast, history of trauma or TMJ surgery, congenital anomalies, metallic artifacts, orthodontic appliances, or incomplete demographic data.25 Participants were stratified into three age groups:  Group 1: 20–39 years (n=100)  Group 2: 40–59 years (n=100)  Group 3: ≥60 years (n=100) Imaging Protocol All scans were obtained using the iCAT Classic CT machine with standardized settings: 120 kVp, 5 mA, isotropic voxel size 0.30 mm, 16×13 cm FOV, 0.5 mm slice thickness, and high-resolution bone reconstruction. Patients were positioned with the Frankfurt plane parallel and teeth in centric occlusion. Images were processed in DICOM format and evaluated in axial, coronal, and sagittal views. Morphometric and Morphological Analysis Image assessment was performed using OsiriX MD software on calibrated high-resolution monitors. Qualitative parameters included condylar flattening, sclerosis, erosion, osteophytes, and subchondral cysts. Quantitative measurements included condylar height, width, depth, volume, and anterior, superior, and posterior joint spaces, along with glenoid fossa depth and eminence angulation. Measurements were recorded bilaterally using standardized protocols. Statistical Analysis and Reliability Data analysis was conducted using SPSS v29.0. Chisquare, ANOVA, Kruskal–Wallis, Pearson/Spearman correlation, and regression analyses were applied (p < 0.05). Intraand inter-observer reliability was evaluated on 60 scans using ICC and Dahlberg’s formula, with ICC ≥0.90 indicating excellent agreement. Figure 1: Schematic diagram of methodology. Results The present cross-sectional study titled “A study to assess the morphometric and morphological changes of the temporomandibular joint (TMJ) with respect to age and gender using CBCT” included 300 subjects (157 males, 143 females). Table 1 and Graph 1 present the age–gender distribution, showing equal allocation into three age groups (20–39, 40–59, ≥60 years), ensuring balanced comparison across age categories. Dr. Abha Verma, et al. International Journal of Dental Science and Innovative Research (IJDSIR) ©2025 IJDSIR, All Rights Reserved Page52 Page52 Page52 Page52 Page52 Page52 Page52 Page52 Page52 Page52 Page52 Page52 Page52 Page52 Page52 Page52 Page52 Page52 Page52 Table 1 and Graph 1: Distribution of Study Participants by Age and Gender Table 2 and Graph 2 summarize TMJ morphological features, where condylar flattening (23%) was the most common finding, followed by cortical sclerosis (17.3%), osteophytes (11.3%), and erosions (9%). Subchondral cysts (4.6%) were least frequent. These patterns indicate early and progressive degenerative or adaptive remodeling changes. (Photograph 2) Table 2 and Graph 2: Descriptive Statistics and Prevalence of TMJ Morphological Variations. Figure 2: Morphological Variations of TMJ: Sagittal and axial with Flattening and Cortical Sclerosis, Axial Showing Osteophyte. Age-wise evaluation (Table 3 and Graph 3) showed a significant increase in degenerative features with age (p ≤ 0.01). Cortical sclerosis exhibited the strongest age association (χ² = 26.87, p < 0.001), while subchondral cysts showed no significant age trend. Table 3 and Graph 3: Comparison of TMJ Morphological Variations Across Age Groups. Dr. Abha Verma, et al. International Journal of Dental Science and Innovative Research (IJDSIR) ©2025 IJDSIR, All Rights Reserved Page53 Page53 Page53 Page53 Page53 Page53 Page53 Page53 Page53 Page53 Page53 Page53 Page53 Page53 Page53 Page53 Page53 Page53 Page53 Morphometric assessment (Table 4 and Graph 4) revealed a gradual reduction in condylar width, height, and volume with increasing age (p < 0.01). Table 4 and Graph 4: Age-wise Comparison of Mean Condylar Morphometric Parameters. Joint space measurements (Table 5 and Graph 5) showed significant narrowing of superior and posterior joint spaces (p = 0.012, p = 0.027), whereas anterior joint space remained unaffected. Table 5 and Graph 5: Age-wise Comparison of TMJ Joint Space Measurements. Correlation analysis (Table 6 and Graph 6) demonstrated significant negative correlations between age and condylar height (r = –0.372), width (r = –0.254), and joint space (r = –0.185), suggesting age-related structural decline. Table 6 and Graph 6: Correlation Between Age and TMJ Morphometric Parameters. Dr. Abha Verma, et al. International Journal of Dental Science and Innovative Research (IJDSIR) ©2025 IJDSIR, All Rights Reserved Page54 Page54 Page54 Page54 Page54 Page54 Page54 Page54 Page54 Page54 Page54 Page54 Page54 Page54 Page54 Page54 Page54 Page54 Page54 Reliability testing (Table 7 and Graph 7) showed excellent intraand inter-observer agreement (ICC > 0.90), confirming measurement accuracy. Table 7 and Graph 7: Intraand Inter-Observer Reliability of TMJ Morphometric Measurements. Descriptive statistics (Table 8 and Graph 8) provided baseline TMJ dimensions, showing minimal intra-sample variability. Table 8 and Graph 8: Prevalence and Distribution of TMJ Morphological and Morphometric Parameters. Gender comparison (Table 9 and Graph 9) revealed significantly higher condylar dimensions in males (p < 0.05), while joint spaces showed no major sex differences. Table 9 and Graph 9: Gender-wise Comparison of TMJ Morphometric Parameters. Overall statistical associations (Table 10) confirmed that TMJ morphology and morphometry exhibit significant age-related structural and degenerative changes, supported by highly reliable CBCT measurements. Table 10: Summary of Significant Findings Dr. Abha Verma, et al. International Journal of Dental Science and Innovative Research (IJDSIR) ©2025 IJDSIR, All Rights Reserved Page55 Page55 Page55 Page55 Page55 Page55 Page55 Page55 Page55 Page55 Page55 Page55 Page55 Page55 Page55 Page55 Page55 Page55 Page55 Discussion The present study comprehensively evaluated the morphological and morphometric features of the temporomandibular joint (TMJ) using digital computed tomography in an adult population. The findings demonstrated considerable variability in condylar shape, joint space dimensions, and degenerative changes, consistent with previously reported anatomical diversity of the TMJ25. Age-related differences were evident, with older individuals exhibiting a higher prevalence of flattening, erosion, and reduced joint space measurements, reflecting physiological remodeling and early degenerative transformations associated with functional loading over time26. Gender-based comparisons revealed that males generally exhibited larger condylar dimensions compared with females⁴, which aligns with broader craniofacial structural differences reported in anthropometric research. However, qualitative morphological variations such as osteophytes, subcortical sclerosis, and condylar asymmetry did not show a marked gender predilection, suggesting that degenerative patterns may be more closely associated with biomechanical factors rather than sex-specific predisposition27-28. Correlation analysis demonstrated a significant association between age and morphometric parameters, particularly condylar height reduction and joint space narrowing. These radiological indicators may serve as early predictors of temporomandibular disorders (TMD), especially in individuals with parafunctional habits, malocclusion, or a history of recurrent subluxation29,30. Reliability testing showed excellent intraand interobserver agreement, confirming that CT-based evaluation is a robust method for studying subtle osseous changes in the TMJ. The detailed visualization provided by CT enables accurate assessment of condylar morphology and degenerative alterations, enhancing diagnostic confidence and supporting clinical decision-making31-33. Overall, the findings highlight the significance of imaging in understanding normal anatomical variations, diagnosing early degenerative changes, and aiding clinicians in appropriate management of TMJ-related conditions34,35,36. This study had several limitations. First, its crosssectional design prevented evaluation of temporal or progressive changes in TMJ morphology. A longitudinal approach would provide stronger evidence regarding the natural course of remodeling and degeneration. Second, clinical and functional parameters—such as occlusal characteristics, parafunctional habits, and symptom severity—were not analyzed alongside radiological findings, which may have limited clinico-radiological correlation37-40. Third, although CT is excellent for assessing bony structures, it does not capture soft tissue details such as disc position, capsule integrity, or retrodiscal tissue status¹⁴. The study sample was also limited to a specific geographic region, which may restrict generalizability of the results41. Future research should focus on longitudinal studies to track progressive TMJ changes across different age groups42. Integrating CT with MRI would allow comprehensive evaluation of both osseous and soft tissue structures, improving diagnostic accuracy43. Further work should incorporate functional assessments—occlusal analysis, muscle activity studies, and clinical symptom scoring—to strengthen clinico-radiological associations44. Expanding the sample size to include diverse ethnic and demographic groups may help establish normative reference data for TMJ morphometry45. Additionally, emerging technologies such as 3D reconstruction, AI-based morphometric analysis, and automated segmentation hold potential for Dr. Abha Verma, et al. International Journal of Dental Science and Innovative Research (IJDSIR) ©2025 IJDSIR, All Rights Reserved Page56 Page56 Page56 Page56 Page56 Page56 Page56 Page56 Page56 Page56 Page56 Page56 Page56 Page56 Page56 Page56 Page56 Page56 Page56 early detection of subtle TMJ abnormalities46. Such advancements may support personalized treatment planning and improved outcomes for patients with TMJ disorders47-50. Conclusion The temporomandibular joint (TMJ) is a complex, functionally adaptive articulation that remodels continuously in response to mechanical loading and agerelated changes. This CBCT-based study systematically evaluated TMJ morphology and morphometry in an Indian population, focusing on condylar height, width, volume, and joint space dimensions across different age and gender groups. CBCT provided high-resolution, three-dimensional imaging with excellent reproducibility (ICC > 0.90), enabling accurate quantification of structural variations. Morphological assessment revealed condylar flattening (23%) as the most prevalent feature, followed by cortical sclerosis (17.3%) and osteophyte formation (11.3%), indicating ongoing adaptive remodeling rather than pathological degeneration. Morphometric analysis demonstrated a significant agerelated reduction in condylar dimensions, with condylar height showing the strongest negative correlation with age (r = –0.372, p < 0.001). Superior and posterior joint spaces also decreased with age, reflecting remodeling of the articular surfaces and cartilage thinning. Genderbased comparisons showed that males exhibited larger condylar dimensions and fossa depth, while joint space symmetry was preserved across sexes, highlighting sexual dimorphism in craniofacial anatomy. These findings reinforce that TMJ remodeling is a physiological, dynamic process that maintains joint function under mechanical stress. The study provides normative reference values for the Indian population and underscores the clinical utility of CBCT in diagnosing, planning, and managing TMJ-related conditions. References 1. Okeson JP. Management of Temporomandibular Disorders and Occlusion. 8th ed. St. Louis: Elsevier; 2019. 2. Tanaka E, Detamore MS, Mercuri LG. Degenerative disorders of the temporomandibular joint: Etiology, diagnosis, and treatment. J Dent Res. 2008;87(4):296–307. 3. De Leeuw R, Klasser GD. 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