Cone-beam computed tomography findings of temporomandibular joints with osseous abnormalities

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1 Oral Radiol (2012) 28:82 86 DOI /s ORIGINAL ARTICLE Cone-beam computed tomography findings of temporomandibular joints with osseous abnormalities Mustafa Alkhader Ra ed Al-Sadhan Reema Al-Shawaf Received: 4 November 2011 / Accepted: 13 December 2011 / Published online: 19 May 2012 Ó Japanese Society for Oral and Maxillofacial Radiology and Springer 2012 Abstract Objective To evaluate the cone-beam computed tomography (CBCT) findings of temporomandibular joints (TMJs) with osseous abnormalities. Methods CBCT images of 88 TMJs in 44 patients with arthrogenic TMJ disorder and 40 normal TMJs of 20 asymptomatic patients were selected for the study. All images were used for evaluation of the condyles (position and width), glenoid fossae (width and depth), and joint spaces (anterior, posterior, and maximum superior). The frequencies of the condylar positions were compared between the two groups using the Chi-square test. The mean values of the remaining CBCT findings were compared between the two groups using the Mann Whitney U test. Results In the 88 TMJs with osseous abnormalities, a dorsal position of the condyle was most frequently seen (62/88), whereas central and ventral positions of the condyle were seen in two and 24 joints, respectively. The TMJs with osseous abnormalities exhibited a significantly lower mean value for the condyle width and a significantly higher mean value for the anterior joint space than the TMJs without such abnormalities. Conclusions Small and dorsally positioned condyles are characteristic CBCT findings of TMJs with osseous abnormalities. Keywords TMJ osseous abnormalities Condyle Glenoid fossa Joint space CBCT M. Alkhader (&) R. Al-Sadhan R. Al-Shawaf Department of Oral Medicine and Diagnostic Sciences, College of Dentistry, King Saud University, P.O. Box 60169, Riyadh 11545, Saudi Arabia arukaderu@yahoo.com Introduction The presence of osseous abnormalities in the temporomandibular joint (TMJ) can be associated with different clinical signs and symptoms [1 4], and can lead to temporomandibular disorders (TMDs) [5 7]. Therefore, accurate diagnosis and early prediction of these abnormalities are paramount. A previous study indicated that the presence of TMJ osseous abnormalities is significantly associated with anterior disc displacement without reduction and disc deformity [8]. However, neither that study nor other previous studies examined the relationships between the presence of osseous abnormalities and the morphologies of the condyle, glenoid fossa, and joint space. For evaluation of the osseous components of TMJs, computerized tomography (CT) and cone-beam computerized tomography (CBCT) are considered to be the primary imaging techniques of choice [9 11]. Thus, the aim of the present study was to evaluate selected anatomic relationships in the condyle fossa complex on CBCT images to clarify which of these relationships are associated with TMJ osseous abnormalities. Materials and methods Patients Forty-four patients with arthrogenic TMJ disorder and 20 asymptomatic patients who consulted our dental clinics between January 2008 and January 2011 and underwent a CBCT examination were included in this study. The patients comprised 22 males (mean age 28 years; age range years) and 42 females (mean age 33 years; age

2 Oral Radiol (2012) 28: range years). This retrospective study was approved by our institutional review board. CBCT examination As the CBCT apparatus, an Iluma cone beam CT system (Imtec Imaging, Ardmore, OK, USA) was used. The CBCT imaging area was a cylinder with a height of 19 cm and a diameter of 24 cm that provided isotropic cubic voxels with sides approximating 0.3 mm. The TMJs were examined bilaterally and imaged at a tube voltage of 120 kv, tube current of 3.8 ma, and exposure time of 40 s. All examinations were performed with 360 rotation in the occlusal position while the patient was sitting with their mouth closed. After scanning, contiguous sectional images in three planes, i.e., parasagittal sections (vertical to the long axis of the condylar head), coronal sections (parallel to the long axis of the condylar head), and horizontal sections, were reconstructed from the projected data with a slice width of 0.3 mm using dedicated CBCT software (Iluma Vision Viewer; Imtec Imaging). PJS MSJS CW Fig. 1 Diagram showing the anterior joint space (AJS), posterior joint space (PJS), maximum superior joint space (MSJS), and condyle width (CW) FW FD AJS Evaluation of images Two calibrated and certified oral radiologists (M.A. and R.Al-Sh.) with 5 and 3 years of experience with CBCT for maxillofacial diagnosis, including TMJ evaluation, independently evaluated the CBCT images. The presence and absence of different kinds of osseous abnormalities, namely flattening, erosion, osteophytes, subcondylar cysts, sclerosis, position and width of the condyles, width and depth of the glenoid fossae, and measurements of the joint spaces (anterior, posterior, and maximum superior), were recorded. The images were evaluated on an LCD monitor installed with the Iluma Vision Viewer. When necessary, the window setting was adjusted to optimize the images for evaluation. In cases of disagreement regarding the presence and absence of osseous abnormalities, the observers evaluated the images for a second time and a consensus was reached after discussion. For the rest of the measurements on the parasagittal sections in the closed mouth position, a cut in the middle condylar axis that showed the osseous abnormalities was used and the interobserver agreement was evaluated with Pearson s correlation coefficient. Following the examples in Pullinger et al. [12], the anterior joint space and posterior joint space were measured as the smallest distance between the anterior and posterior surfaces of the condyle and fossa, respectively, and the maximum superior joint space was measured as the vertical distance between the deepest point of the fossa to the condyle (Fig. 1). The condyle width was measured as the dimension between the anterior and posterior condyle outlines along a tangent drawn between the deepest point Fig. 2 Diagram showing the fossa depth (FD) and fossa width (FW) of the eminence and the posterior glenoid process (Fig. 1). The fossa width was measured as the distance between the most inferior point on the articular eminence and the posterior glenoid process (Fig. 2). The fossa depth was measured as the distance between the deepest point of the fossa and a point where the connecting line met the fossa width tangent at a right angle (Fig. 2). For the condylar position, the Pullinger and Hollender equation [12] was used condylar position = posterior joint space - anterior joint space/posterior joint space? anterior joint space and the position of the condyle was considered central if the result was zero, ventral if the result was positive, and dorsal if the result was negative. All the TMJs were classified into two groups: TMJs with osseous abnormalities (88 TMJs) and TMJs without osseous abnormalities (40 TMJs). Statistical analysis The Chi-square test was used to compare the frequencies of the condyle positions between the two groups. The mean values of the remaining of CBCT findings were compared between the two groups using the Mann Whitney U test. Pearson s correlation coefficients were calculated to evaluate the interobserver agreement for all measurements on

84 Oral Radiol (2012) 28:82 86 the basis of the following criteria: less than 0.40, poor agreement; 0.40 0.59, fair agreement; 0.60 0.74, good agreement; and 0.75 1.00, excellent agreement.

3 84 Oral Radiol (2012) 28:82 86 the basis of the following criteria: less than 0.40, poor agreement; , fair agreement; , good agreement; and , excellent agreement. All statistical analyses were carried out using statistical software (SPSS version 16; SPSS, Chicago, IL, USA). Results The osseous abnormalities revealed by the CBCT images were flattening, erosion, osteophytes, subcondylar cysts, and sclerosis, and these abnormalities were observed in 88, 30, 28, 17, and 69 TMJs, respectively. The interobserver agreements were fair, good, or excellent for all measurements. The Pearson s correlation coefficients for the condyle width, fossa width, fossa depth, anterior joint space, posterior joint space, and maximum superior joint space were 0.83, 0.55, 0.67, 0.78, 0.73, and 0.78, respectively. Given the low interobserver variability, the measurements from the two observers were averaged to obtain mean values. In the 88 TMJs with osseous abnormalities, a dorsal position of the condyle was significantly more frequent compared with TMJs without such abnormalities (62/88 vs. 16/40, p \ 0.05 by the Chi-square, Table 1). Central and ventral positions of the condyle were observed in two and 24 TMJs with osseous abnormalities, respectively (Table 1). In the 40 TMJs without osseous abnormalities (Fig. 3), a ventral position of the condyle was the most frequent position (22/40), whereas central and dorsal positions were only found in two and 16 TMJs, respectively (Table 1). The mean values of the fossa width and posterior joint space were lower in TMJs with osseous abnormalities than in TMJs without such abnormalities, whereas the mean values of the fossa depth and maximum superior joint space were higher in TMJs with osseous abnormalities than in TMJs without such abnormalities (Table 2). Compared with the TMJs without osseous abnormalities, the TMJs with osseous abnormalities showed a significantly lower mean value for the condyle width (Fig. 4; p \ 0.05 by the Mann Whitney U test, Table 2) and a significantly higher mean value for the anterior joint space (Fig. 3; p \ 0.05 by the Mann Whitney U test, Table 2). Discussion Osseous abnormalities affecting the TMJ have been shown to be associated with different hard and soft tissue abnormalities affecting the condyle fossa complex [8, 13 17]. Therefore, studying the anatomical characteristics of the condyle fossa complex might help toward the Table 1 Frequencies of the condylar positions in 128 TMJs with and without osseous abnormalities Osseous abnormalities Condylar position Total Central Ventral Dorsal Absent Present * 88 Total * p \ 0.05, significant difference by the Chi-square test Fig. 3 CBCT sagittal image showing a normal TMJ Table 2 Descriptive statistics of the CBCT findings Osseous abnormalities n Mean SD FW Absent Present FD Absent Present CW Absent Present * 1.42 PJS Absent Present AJS Absent Present * 0.82 MSJS Absent Present FW fossa width, FD fossa depth, CW condyle width, PJS posterior joint space, AJS anterior joint space, MSJS maximum superior joint space * p \ 0.05, significant difference by the Mann Whitney U test

4 Oral Radiol (2012) 28: Fig. 4 CBCT sagittal image showing a condyle with a small width and osteophytes at the same time identification of patients at risk of developing osseous abnormalities in the future. Among previous studies, Honda et al. [15] compared the minimum thickness of the roof of the glenoid fossa between different TMJ autopsy specimens, and showed that the thickness increases when the TMJ has osteoarthritic changes in addition to disc displacement or disc perforation. In the study by Tsuruta et al. [16], the minimum thickness of the roof of the glenoid fossa was associated and increased with the presence of bony abnormalities affecting the condylar head, and was also dependent on the type of bony abnormality. In both of these reports, the authors explained that the increase in the minimum thickness of the roof of the glenoid fossa might help with shock absorption and better distribution of stress accompanying changes in the TMJ condylar bone. Furthermore, these studies indicated that an increase in the minimum thickness of the roof of the glenoid fossa in the presence of osseous abnormalities can result in a decrease in the fossa depth. However, this was not the case in the present study, and this discrepancy can be explained by the use of different sections for the evaluations in our study. Regarding other TMJ anatomic relationships, most of them were formulated and investigated in relation to disc displacement by Pullinger et al. [12]. However, to best of our knowledge, there is no published research showing the associations between the presence of TMJ osseous abnormalities and the anatomic relationships of the condyle fossa complex using the methods of Pullinger et al. [12]. In the present study, we evaluated some of the condyle fossa anatomic relationships that have not previously been investigated in association with the presence of TMJ osseous abnormalities. Fig. 5 CBCT sagittal image showing an increase in the anterior joint space in the condyle with flattening and osteophytes The appearance of the condyle position in the glenoid fossa can be affected by several factors, including the disc position [17], disc morphology [18], and morphology of the condylar head [19], and there is no agreement among authors in relation to the ideal position of the condyle [20]. In contrast to Tsuruta et al. [21], our study showed that most of the TMJs with osseous abnormalities had a dorsal position (62/88) and that this position was significantly more frequent compared with the TMJs without such abnormalities. In Tsuruta et al. [21], a ventral position of the condyle was most commonly associated with the presence of osteophytes, whereas only 28 TMJs with osteophytes were observed in our study. Around 61 % of the TMJs in patients with TMDs included in the study, either with or without osseous abnormalities, had a dorsal position, and this could be caused by the presence of anterior disc displacement [22], which we were not able to evaluate in our retrospective study. These findings are similar to those in several previous studies [17, 20, 23, 24]. According to the methods of Pullinger et al. [12], the position of the condyle in the fossa is relative. Therefore, having a condyle in a ventral or dorsal position does not mean that the position is abnormal. Even in asymptomatic subjects, random positions of the condyle in the fossa are expected [24]. Since most of the TMJs with osseous abnormalities had a dorsal position, this resulted in the increase in the anterior joint space and a decrease in the posterior joint space. The increase in the maximum superior joint space in the presence of osseous abnormalities could be caused by slight inferior positions of the condyles (Fig. 5).

5 86 Oral Radiol (2012) 28:82 86 Small condyles with a decrease in width are likely to reveal osseous abnormalities, because they have less tolerance for load in the joint [5], and this was also the case in the present study. Our study has some limitations. First, we did not evaluate the status of the disc in relation to our findings, although this could affect the condyle positions and joint spaces. Second, we could not establish cause-and-effect relationships between the presence of TMJ osseous abnormalities and abnormal anatomic relationships of the condyle fossa complex, and longitudinal studies will be needed to resolve this issue. Third, using the methods of Pullinger et al. [12] for studying other anatomic relationships of the condyle fossa complex might provide a better idea about the presence of TMJ osseous abnormalities and help toward better understanding of the underlying mechanisms. Finally, in comparison with other CBCT machines with a small field of view, the field of view was large in this retrospective study, and this could result in higher radiation doses to the patients. In conclusion, CBCT examination of patients with small and dorsally positioned condyles is useful, because they are associated with the presence of osseous abnormalities in the TMJ and these abnormalities might lead to the development of degenerative joint disease in the future. References 1. Helenius LMJ, Tervahartiala P, Helenius I, Al-Sukhun J, Kivisaari L, Suuronen R, et al. Clinical, radiographic and MRI findings of the temporomandibular joint in patients with different rheumatic diseases. Int J Oral Maxillofac Surg. 2006;35: Campos MI, Campos PS, Cangussu MC, Guimarães RC, Line SR. Analysis of magnetic resonance imaging characteristics and pain in temporomandibular joints with and without degenerative changes of the condyle. Int J Oral Maxillofac Surg. 2008;37: Takahashi A, Murakami S, Nishiyama H, Sasai T, Fujishita M, Fuchihata H. The clinicoradiologic predictability of perforations of the soft tissue of the temporomandibular joint. Oral Surg Oral Med Oral Pathol. 1992;74: Scrivani SJ, Keirh DA, Kaban LB. Temporomandibular disorders. N Engl J Med. 2008;359: Okeson JP. Management of temporomandibular disorders and occlusion. 6th ed. St. Louis: Mosby; Laskin DM, Greene CS, Hylander WL. Temporomandibular disorders: an evidence-based approach to diagnosis and treatment. 1st ed. Hanover Park: Quintessence; Wright EF. Manual of temporomandibular disorders. 2nd ed. Ames: Blackwell Munksgaard; Alkhader M, Kuribayashi A, Ohbayashi N, Nakamura S, Kurabayashi T. Usefulness of cone beam computed tomography in temporomandibular joints with soft tissue pathology. Dentomaxillofac Radiol. 2010;39: Arai Y, Tammisalo E, Iwai K, Hashimoto K, Shinoda K. Development of a compact tomographic apparatus for dental use. Dentomaxillofac Radiol. 1999;28: Honda K, Larheim TA, Maruhashi K, Matsumoto K, Iwai K. Osseous abnormalities of the mandibular condyle: diagnostic reliability of cone beam computed tomography with helical computed tomography based on an autopsy material. Dentomaxillofac Radiol. 2006;35: Honey OB, Scarfe WC, Hilgers M, Klueber K, Silveira A, Haskell B, et al. Accuracy of cone-beam computed tomography imaging of the temporomandibular joint: comparisons with panoramic radiology and linear tomography. Am J Orthod Dentofac Orthop. 2007;132: Pullinger AG, Seligman DA, John MT, Harkins S. Multifactorial comparison of disk displacement with and without reduction to normals according to temporomandibular joint hard tissue anatomic relationships. J Prosthet Dent. 2002;87: Hirata FH, Guimaraes AS, Oliveira JX, Moreira CR, Ferreira ETT, Cavalcanti MGP. Evaluation of TMJ articular eminence morphology and disc patterns in patients with disc displacement in MRI. Braz Oral Res. 2007;21: Sato S, Kawamura H. Changes in condylar mobility and radiographic alterations after treatment in patients with non-reducing disc displacement of the temporomandibular joint. Dentomaxillofac Radiol. 2006;35: Honda K, Larheim TA, Sano T, Hashimoto K, Shinoda K, Westesson PL. Thickening of the glenoid fossa in osteoarthritis of the temporomandibular joint. An autopsy study. Dentomaxillofac Radiol. 2001;30: Tsuruta A, Yamada K, Hanada K, Hosogai A, Tanaka R, Koyama J, et al. Thickness of the roof of the glenoid fossa and condylar bone change: a CT study. Dentomaxillofac Radiol. 2003;32: Kurita H, Ohtsuka A, Kobayashi H, Kurashina K. A study of the relationship between the position of the condylar head and displacement of the temporomandibular joint disk. Dentomaxillofac Radiol. 2001;30: Ikeda K, Kawamura A. Assessment of optimal condylar position with limited cone-beam computed tomography. Am J Orthod Dentofacial Orthop. 2009;135: Pandis N, Karpac J, Trevino R, Williams B. A radiographic study of condyle position at various depths of cut in dry skulls with axially corrected lateral tomograms. Am J Orthod Dentofacial Orthop. 1991;100: Gonzalez B. The not-so-controversial issue of condylar position. Int J Orthod Milwaukee. 2007;18: Tsuruta A, Yamada K, Hanada K, Hosogai A, Kohno S, Koyama J, et al. The relationship between morphological changes of the condyle and condylar position in the glenoid fossa. J Orofac Pain. 2004;18: Gateno J, Anderson PB, Xia JJ, Horng JC, Teichgraeber JF, Liebschner MA. A comparative assessment of mandibular condylar position in patients with anterior disc displacement of the temporomandibular joint. J Oral Maxillofac Surg. 2004;62: Di Paolo C, D Ambrosio F, Panti F, Papa M, Mancini P. The condyle fossa relationship in temporomandibular disorders. Considerations on the pathogenetic role of the disc. Minerva Stomatol. 2006;55: Ren YF, Isberg A, Westesson PL. Condyle position in the temporomandibular joint. Comparison between asymptomatic volunteers with normal disk position and patients with disk displacement. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1995;80:101 7.

Artigo Original / Original Article

Artigo Original / Original Article IJD ISSN:1806-146X Mandibular condyle morphology on panoramic radiographs of asymptomatic temporomandibular joints Christiano Oliveira 1 Renata Tarnoschi Bernardo 2 Ana