Lamia F.docx J Bagh College Dentistry Vol. 28(2), June 2016 An assessment of Oral Diagnosis 58 An Assessment of Sagittal Condylar Position of TMJ Dysfunction in Centric Occlusion by Using Cone Beam Computed Tomography Lamia H. Al-Nakib, B.D.S, M.Sc. (1) Ako Omer Abdullah,B.D.S., M.Sc. (2) Saeed A.Abd Al-Kareem, B.D.S., M.Sc. (3) Sangar Hamid Ali, B.D.S., M.Sc. (4) ABSTRACT Background: Temporomandibular joint (TMJ) is a compound articulation formed from the articular surfaces of the temporal bone and the mandibular condyle.CBCT imaging of TMJ is that it allows accurate measurements of the volume and surface of the condyle. The aim of the study is to assess the sagittal position of mandibular condyle in patients with temporomandibulardysfunction using Cone Beam Computed Tomography in centric occlusion. Materials and Methods: CBCT images for all patients were obtained in an upright position using New Tom Giano CBCT with different field of view (11 x 8), (11 x 5), and (8 x 8) and exposure factors was changed accordingly using NNT version 5.1 software for sagittal reconstruction, anterior, superior and posterior joint spaces was measured. Results: There was a significant change in the anterior, posterior and superior joint spaces when compared to normal functioning TMJ. The sagittal position of the condyle in glenoid fossa could be affected by TMJ dysfunction and it would be positioned centrally but slightly inferior to the normal position according to the results of this study. There was no significant difference in the sagittal condylar position in glenoid fossa between sexes. There was significant difference in the value of anterior, posterior and superior TMJ spaces between right and left sides of the mandible in both normal cases and TMJD. Conclusion: Sagittal section of Temporomandibular joint revealed that TMJ dysfunction affects the joint spaces in sagittal plane. It means significant changes occur in the value of anterior, posterior and superior joint spaces when compared to normal functioning TMJ. Keywords: Condylar Position, TMJ Dysfunction Cone Beam Computed Tomography. (J Bagh Coll Dentistry 2016; 28(2):58-62). INTRODUCTION Temporomandibular joint (TMJ) is one of the complex joints of the body which comprises the mandibular condyle, and the temporal bone forming the superior component of the joint (1). The articular eminence is a part of the temporal bone on which the condylar process slides during mandibular movements (2). An articular disk is interposed between the temporal bone and the mandible, dividing the joint space into two components, i.e. an upper one in which gliding movements occur, and a lower one characterized by rotation or hinge movements. Temporomandibular joint is morphologically structured to support the specialized functional demands of mastication(3). A fundamental question in dentistry is what to be regarded as the optimal position of the condyle in the glenoid fossa when the teeth are in maximum intercuspation (4). (1)Professor, Department of Oral Diagnosis, College of Dentistry/ University of Baghdad. (2)Specialist Dentist, Sulaimania Directory of Health, Ministry of Health in Kurdistan rejoin. (3) Assistant Professor, Department of Oral Diagnosis, School of Dentistry, Faculty of Medical Sciences/University of Sulaimania. (4) Specialist Dentist, Khanzad Teaching center/ Erbil,Ministry of Health in Kurdistan rejoin. The optimal condylar position in the glenoid fossa can be determined by the dimension of the joint space. Radiographically the joint space is a total term that is used for the description of the radiolucent zone that is placed between condylar and temporal parts (5). Standard radiographic studies of the temporomandibular joint (TMJ), such as the plain film radiography and panoramic radiography, have little capacity to reveal anything more than gross osseous changes within the joint (6). The use of conventional radiographs has inherent limitations such as structural superimpositions in two-dimensional imaging, particularly in the region of the petrous temporal bone, the mastoid process, and the articular eminence, which indeed limits an accurate view of the TMJ (7). Even conventional CT was used for TMJ evaluation and it was with reasonable results (8) but CT is performed with the patient in the supine position, rather than in the upright position, which may have led to errors in the evaluation of the condyle-fossa relationships (9). The high cost, access to equipment, motion artifact and the relatively high radiation dose have limited the widespread use of CT for TMJ evaluation (10).While Magnetic Resonance Imaging (MRI) is J Bagh College Dentistry Vol. 28(2), June 2016 An assessment of Oral Diagnosis 59 considered as one of the most useful tools that shows disc displacement. Unfortunately, MRI gives little information of the bone TMJ structures (5). Cone Beam Computed Tomography (CBCT) for dental and maxillofacial diagnostic osseous tasks has been developed as an alternative to conventional CT, the results of CBCT technology in images of CT-like quality were obtained on the basis of less expensive equipment and components, shorter patient examination time and much lower radiation dose than required for conventional CT. In addition, the scanning procedure of the patient and the software for image reconstruction connected with CBCT are very user-friendly (11). Cone Beam Computed Tomography is similar to conventional CT in diagnosing different osseous conditions and that it provides a cost- and dose effective diagnostic options (12) . A large body of literatures has been published recently about CBCT in Temporomandibular joint imaging due to the fact that CBCT has inspired research in TMJ imaging. An important advantage of CBCT imaging of TMJ is that it allows accurate measurements of the volume and surface of the condyle. These measurements are extremely advantageous in the clinical practice when treating patients with TMJ dysfunctions (13). Many in vitro cadaveric studies have explored the role of CBCT in assessing bony defects and osteophytes. Erosive changes in the TMJ are most effectively diagnosed using CBCT in the 6 inch FOV as compared to the 12 inch FOV(14). Alkhader et al.(15)performed a comparative study between CBCT and MRI and it was revealed that CBCT is better than MRI in detecting changes in shape (flattening, osteophyte formation or erosion) rather than changes in size, however there is a poor correlation between condylar changes observed on CBCT images and clinical signs and symptoms seen in patients with TMJ osteoarthritis (OA), CBCT plays an important role in diagnosing early stages of juvenile idiopathic arthritis (JIA) in children which, when undetected, can damage facial development and cause growth alterations. Farronato et al.(16)concluded from their study that CBCT can be used to volumetrically quantify the TMJ damage in these patients by measuring condylar and mandibular volumes. MATERIALS AND METHODS After approval of scientific Ethical committee/School of Dentistry at Sulaimany University a cross-sectional study carried out on thirty-two patients attending Oral and Maxillofacial Department of Dental center in Erbil city from February to June 2014. (All patients were between 20 to 35 years old). Patients were classified into two groups, Control group: 32 joints of 16 patients (8 males and 8 females) attending Denta center for different purposes other than TMJ problems and TMJD group: 32 joint of 16 patients with pre diagnosed to have TMJ dysfunction by Oral medicine specialist (8 males and 8 females). CBCT images for all patients were obtained in an upright position using New Tom Giano CBCT with different field of view (11 x 8), (11 x 5), and (8 x 8) and exposure factors will be change accordingly using NNT version 5.1 software for sagittal reconstruction. At the beginning, on axial slices, the cut that showed the largest medio-lateral dimension of condylar heads was selected (Figure 1). Figure 1: Largest medio-lateral dimension of condylar head on axial slice Next, true sagittal images with 0.15 mm thickness and interval distance on medio-lateral axis of condyle were reconstructed then, two true central sagittal images with 0.15 mm thickness and interval distance were chosen. After that, anterior, superior and posterior joint spaces were measured on these reconstructed sagittal images. Initially, a horizontal line on uppermost area of glenoid fossa was drawn and the intersection of this line with glenoid fossa was selected as superior reference point (S), sequentially, this point was connected to the most prominent points on anterior (A) and posterior (P) aspects of the condyle. Finally, the perpendicular distance from A and P tangent points to glenoid fossa was measured as anterior and posterior joint spaces (AJS, PJS), The right distance between S point and superior prominent point of condylar head were considered as superior joint space (Sjs). An NNT version 5.1 software was used for sagittal reconstruction and measurements (Figure 2). J BagJ Bagh College Dentistry Oral Diagnosis Figure 3: Measurement of superior, anterior and posterior joint spaces RESULTS Thirty two patients were participated in this study (16 males two groups, control and TMJD group Table 1: Right and left temporo DISCUSSION In the current study, the value of SJS was the greatest among TMJ spaces followed by AJS and PJS in both sexes in control and TMJD groups. This result is in agreement with Ikeda and Kawamura Hansson thickness in autopsy materials and found that the thickness of the posterior and anterior bands was h College Dentistry Oral Diagnosis Figure 3: Measurement of superior, anterior and posterior joint spaces RESULTS Thirty two patients were participated in this study (16 males and 16 females) and were divided into two groups, control and TMJD group Table 1: Right and left temporo Table 2 Table 3: R DISCUSSION In the current study, the value of SJS was the greatest among TMJ spaces followed by AJS and PJS in both sexes in control and TMJD groups. This result is in agreement with Ikeda and Kawamura Hansson et al. (17) who directly thickness in autopsy materials and found that the thickness of the posterior and anterior bands was h College Dentistry Figure 3: Measurement of superior, anterior and posterior joint spaces for male patient with TMJD Thirty two patients were participated in this study and 16 females) and were divided into two groups, control and TMJD group Table 1: Right and left temporo TM Joint space Right AJS Left AJS Right PJS Left PJS Right SJS Left SJS Table 2: Right and left temporomandibular joint spaces in control group TM Joint space AJS PJS SJS Table 3: Right and left tempor TM Joint space AJS PJS SJS In the current study, the value of SJS was the greatest among TMJ spaces followed by AJS and PJS in both sexes in control and TMJD groups. This result is in agreement with Dalili et al Ikeda and Kawamura(4)but is incompatible with who directly thickness in autopsy materials and found that the thickness of the posterior and anterior bands was h College Dentistry Vol. 2 Figure 3: Measurement of superior, anterior for male patient with Thirty two patients were participated in this study and 16 females) and were divided into two groups, control and TMJD group Table 1: Right and left temporo-mandibular joint spaces in control and TMJD groups Joint space Mean Right AJS 2.36 Left AJS 2.01 Right PJS 2.00 Left PJS 2.21 Right SJS 2.43 Left SJS 2.79 Right and left temporomandibular joint spaces in control group TM Joint space AJS 2.36 PJS 2.00 SJS 2.43 ight and left tempor TM Joint space AJS 2.61 PJS 2.18 SJS 3.57 In the current study, the value of SJS was the greatest among TMJ spaces followed by AJS and PJS in both sexes in control and TMJD groups. Dalili et al. (5) and but is incompatible with measured disc thickness in autopsy materials and found that the thickness of the posterior and anterior bands was Vol. 28(2), June 60 Figure 3: Measurement of superior, anterior for male patient with Thirty two patients were participated in this study and 16 females) and were divided into The mean age 3.6 years and that of (Temporo dysfunction) TMJD group was 29.3 with similar sex distribution TMJD group and control group (all three spaces were presented to be larger in TMJD group than control group, P<0.01 and P<0.0 (Table 1), but a non sexes when a comparison of temporomandibular joint spaces (AJS, PJS, and SJS) in control and TMJD groups were Table 2 shows the mean temporomandibular joint space in control group. Right AJS was signif while the left PJS and SJS were significantly higher than the right PJS and SJS, P<0.01 and P<0.05. Table 3 shows the mean temporomandibular joint space in TMJD group. The right AJS was significantly left AJS, however the left PJS and SJS were significantly higher than the right PJS and SJS, P<0.05 and P<0.01 respectively. mandibular joint spaces in control and TMJD groups Control Mean + SD Mean 2.36 + 0.31 2.01 + 0.26 2.24 2.00 + 0.12 2.18 2.21 + 0.18 2.35 2.43 + 0.17 3.57 2.79 + 0.41 3.85 Right and left temporomandibular joint spaces in control group Right 2.36 + 0.31 2.01 2.00 + 0.12 2.21 2.43 + 0.17 2.79 ight and left temporomandibular joint spaces in TMJD groups Right 2.61 + 0.42 2.24 2.18 + 0.19 2.35 3.57 + 0.27 3.85 In the current study, the value of SJS was the greatest among TMJ spaces followed by AJS and PJS in both sexes in control and TMJD groups. and but is incompatible with measured disc thickness in autopsy materials and found that the thickness of the posterior and anterior bands was more than that of the intermediate zone. In addition, the significant difference in the thickness of intermediate joi the thickness of the soft tissues covering the fossa. revealed that the values of AJS, PJS, and SJS were greater in TMJD group than in the control group dysfunction which means in the centric position of June 2016 The mean age 3.6 years and that of (Temporo dysfunction) TMJD group was 29.3 with similar sex distribution There was a TMJD group and control group (all three spaces were presented to be larger in TMJD group than control group, P<0.01 and P<0.0 (Table 1), but a non sexes when a comparison of temporomandibular joint spaces (AJS, PJS, and SJS) in control and TMJD groups were Table 2 shows the mean temporomandibular joint space in control group. Right AJS was signif while the left PJS and SJS were significantly higher than the right PJS and SJS, P<0.01 and P<0.05. Table 3 shows the mean temporomandibular joint space in TMJD group. The right AJS was significantly left AJS, however the left PJS and SJS were significantly higher than the right PJS and SJS, P<0.05 and P<0.01 respectively. mandibular joint spaces in control and TMJD groups TMJD Mean + SD 2.61 +0.24 2.24 + 0.16 2.18 + 0.19 2.35 + 0.20 3.57 + 0.27 3.85 + 0.31 Right and left temporomandibular joint spaces in control group Left 2.01 + 0.26 2.21 + 0.18 2.79 + 0.41 omandibular joint spaces in TMJD groups Left 2.24 + 0.16 2.35 + 0.20 3.85 + 0.31 more than that of the intermediate zone. In addition, the significant difference in the thickness of intermediate joi the thickness of the soft tissues covering the fossa. The results obtained in the present study revealed that the values of AJS, PJS, and SJS were greater in TMJD group than in the control group, all the three spaces dysfunction which means in the centric position of + SD of control group was 28.7 3.6 years and that of (Temporo dysfunction) TMJD group was 29.3 with similar sex distribution. There was a significant difference between TMJD group and control group (all three spaces were presented to be larger in TMJD group than control group, P<0.01 and P<0.0 (Table 1), but a non-significant difference sexes when a comparison of temporomandibular joint spaces (AJS, PJS, and SJS) in control and TMJD groups were assessed Table 2 shows the mean + SD of the right and left temporomandibular joint space in control group. Right AJS was significantly higher than left AJS while the left PJS and SJS were significantly higher than the right PJS and SJS, P<0.01 and Table 3 shows the mean + SD of the right and left temporomandibular joint space in TMJD group. The right AJS was significantly left AJS, however the left PJS and SJS were significantly higher than the right PJS and SJS, P<0.05 and P<0.01 respectively. mandibular joint spaces in control and TMJD groups P value 0.016 0.005 0.003 0.046 0.001 0.001 Right and left temporomandibular joint spaces in control group P value 0.028 0.001 0.037 omandibular joint spaces in TMJD groups P value 0.035 0.019 0.001 more than that of the intermediate zone. In addition, the significant difference in the thickness of intermediate joint space can be due to ignoring the thickness of the soft tissues covering the fossa. The results obtained in the present study revealed that the values of AJS, PJS, and SJS were greater in TMJD group than in the control all the three spaces dysfunction which means in the centric position of An assessment SD of control group was 28.7 3.6 years and that of (Temporo-mandibular joint dysfunction) TMJD group was 29.3 + . significant difference between TMJD group and control group (all three spaces were presented to be larger in TMJD group than control group, P<0.01 and P<0.05 in both sides significant difference sexes when a comparison of temporomandibular joint spaces (AJS, PJS, and SJS) in control and assessed (P>0.05). SD of the right and left temporomandibular joint space in control group. icantly higher than left AJS while the left PJS and SJS were significantly higher than the right PJS and SJS, P<0.01 and SD of the right and left temporomandibular joint space in TMJD group. The right AJS was significantly higher than the left AJS, however the left PJS and SJS were significantly higher than the right PJS and SJS, P<0.05 and P<0.01 respectively. mandibular joint spaces in control and TMJD groups Right and left temporomandibular joint spaces in control group omandibular joint spaces in TMJD groups more than that of the intermediate zone. In addition, the significant difference in the thickness nt space can be due to ignoring the thickness of the soft tissues covering the fossa. The results obtained in the present study revealed that the values of AJS, PJS, and SJS were greater in TMJD group than in the control all the three spaces were larger in TMJ dysfunction which means in the centric position of An assessment SD of control group was 28.7 + mandibular joint 4.4 years significant difference between TMJD group and control group (all three spaces were presented to be larger in TMJD group than 5 in both sides significant difference in both sexes when a comparison of temporomandibular joint spaces (AJS, PJS, and SJS) in control and SD of the right and left temporomandibular joint space in control group. icantly higher than left AJS while the left PJS and SJS were significantly higher than the right PJS and SJS, P<0.01 and SD of the right and left temporomandibular joint space in TMJD group. higher than the left AJS, however the left PJS and SJS were significantly higher than the right PJS and SJS, mandibular joint spaces in control and TMJD groups more than that of the intermediate zone. In addition, the significant difference in the thickness nt space can be due to ignoring the thickness of the soft tissues covering the fossa. The results obtained in the present study revealed that the values of AJS, PJS, and SJS were greater in TMJD group than in the control were larger in TMJ dysfunction which means in the centric position of An assessment of J Bagh College Dentistry Vol. 28(2), June 2016 An assessment of Oral Diagnosis 61 mandible in patients with TMJ dysfunction the head of the condyle in the glenoid fossa is positioned more centrally and inferiorly when compared to normal subjects (centrally and slight inferior position is more common than other positions). The results of Wiese et al. (18)and Dalili et al. (5)studies were similar to the present results, that the condyle was positioned centrally in most TMJs. But the results are in agreement with Incesu et al. who reported the posterior position of condyle as the most common position in patients with temporomandibular joint disorder. Sicher et al. (19)wrote that, in all synovial joints in the human body, the articulating surfaces of the opposing bones are kept in firm contact by the associated ligaments and musculature, and that firm contact is maintained with the disc closely fitted between the opposing articular surfaces throughout the range of jaw movement. If this close relationship between the eminence and the condyle is lost due to disc displacement, there should be changes in joint space. The present study included joints with no signs of TMD which were considered as normal samples based only on radiographic and chair-side examinations, and cases having TMD by using pain, joint sound, tenderness of joint area and limitation of mouth opening leaving the possibility of undetected disc displacements. In addition, the normalcy of disc position in a static mandibular position does not ensure its functional normalcy. The older age range of the subjects might be associated with an increased risk of disc displacement and morphologic changes in joint structures. Gateno et al.(20) found that in patients with anterior disc displacement, the position of the condylar head was significantly different than in patients with normal joints in which condylar heads in patients with anterior disc displacement were positioned more posteriorly and superiorly within the fossa than in patients with normal joints. However, there is one author who reported no difference in condylar position between ADD joints and normal joints(21). According to the present result, there is no significant difference in the value of AJS, PJS and SJS between sexes and this result is in agreement with Ikeda and Kawamura(4)and in agreement with Dalili et al. (5), who found that SJS showed statistically significant difference between the genders using limited CBCT. It is also incompatible with Kinniburgh et al. (22)who used the conventional tomography, and this different result may be because of the difference in the population that they took their samples from, compared to the sample of this study which was taken from Kurdish population. In the control group, the value of right AJS was greater than the left side. The left PJS and SJS were significantly higher than the right PJS and SJS. This result was the same for TMJD group. This result is in agreement with Dalili et al. (5). Significant differences between the values of AJA, PJS and SJS in right and left sides were observed in the study by Dalili et al.(5).Previous studies concluded that asymmetric TMJ spaces were usually associated with TMJ dysfunction conversely; bilateral condylar concentricity was associated with an absence of clinical symptoms. 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