Articular Eminence Research Articles

An exchange technique in temporomandibular joint (TMJ) arthroscopy to insert a larger operative cannula to facilitate advanced procedures

The paper describes a modification of the surgical technique for temporomandibular joint arthroscopy, using an exchange guide to replace the 2.2 mm cannula with one of 2.9 mm to better facilitate osteoplasty of the medial wall. The procedure is a simple and safe manoeuvre that reduces complications such as fluid extravasation into soft tissues, damage to the articular eminence, and bleeding into the superior joint space. Every oral and maxillofacial surgeon could benefit from this novel method, which reduces the chances of failure when exchanging the working cannulas, the potential morbidity of re-entry, and the duration of surgery.

Loss of miR-204 and miR-211 shifts osteochondral balance and causes temporomandibular joint osteoarthritis.

Temporomandibular joint (TMJ) osteoarthritis (OA) is a common type of TMJ disorders causing pain and dysfunction in the jaw and surrounding tissues. The causes for TMJ OA are unknown and the underlying mechanism remains to be identified. In this study, we generated genetically-modified mice deficient of two homologous microRNAs, miR-204 and miR-211, both of which were confirmed by in situ hybridization to be expressed in multiple TMJ tissues, including condylar cartilage, articular eminence, and TMJ disc. Importantly, the loss-of-function of miR-204 and miR-211 caused an age-dependent progressive OA-like phenotype, including cartilage degradation and abnormal subchondral bone remodeling. Mechanistically, the TMJ joint deficient of the two microRNAs demonstrated a significant accumulation of RUNX2, a protein directly targeted by miR-204/-211, and upregulations of β-catenin, suggesting a disrupted balance between osteogenesis and chondrogenesis in the TMJ, which may underlie TMJ OA. Moreover, the TMJ with miR-204/-211 loss-of-function displayed an aberrant alteration in both collagen component and cartilage-degrading enzymes and exhibited exacerbated orofacial allodynia, corroborating the degenerative and painful nature of TMJ OA. Together, our results establish a key role of miR-204/-211 in maintaining the osteochondral homeostasis of the TMJ and counteracting OA pathogenesis through repressing the pro-osteogenic factors including RUNX2 and β-catenin.

A Comparison of the Condyle and Articular Eminence in Asian Juvenile Idiopathic Osteoarthritis Patients with Unilateral and Bilateral TMJ Involvement: A Retrospective Case-Control Study.

This study compared the condylar volume, length, and articular eminence (AE) characteristics of normal individuals to those with unilateral and bilateral juvenile idiopathic osteoarthritis (JOA). The 116 patients were divided into four groups: Control (n = 16), affected condyle of unilateral JOA (Aff-Uni) (n = 36), non-affected condyle of JOA (NonAff-uni) (n = 36), and bilateral JOA (Bilateral) (n = 28). The differences in condyle volume and length and AE were analyzed using ANOVA and Bonferroni post-hoc tests. The results showed that Bilateral had a significantly different condylar volume, especially in the condylar head (p < 0.01), specifically the middle, anterior, and medial parts (p < 0.05). Condylar length also differed among the groups, with differences observed between the control group and the other three groups, as well as between the bilateral group and the other three groups (p < 0.01). AE total volume differed between the control group and Aff-Uni. In the detailed comparison, Aff-Uni and NonAff-Uni were smaller than the control group in the posterior, lateral, and medial sections (p < 0.05). In conclusion, depending on the involvement of unilateral or bilateral JOA, there were differences in condylar volume and AE when compared to the normal control group. Therefore, a prognosis should be evaluated by distinguishing between patients with unilateral and bilateral JOA.

Investigation of Condyle Positions in Patients with Temporomandibular Joint Disorder by Cone-Beam Computed Tomography

Objective: The condylar position refers to the location of the mandibular condyle within the glenoid fossa when the teeth are in maximum intercuspal, and it is an important indicator of the temporomandibular joint (TMJ) function. This study aimed to assess the condylar position of the TMJ in patients with TMJ disorder using cone-beam computed tomography (CBCT). Methods: The present study utilized CBCT to evaluate the condylar position of the TMJ in a sample of 56 patients. Among them, 28 patients were asymptomatic while the remaining 28 had been diagnosed with TMJ disease. To evaluate the presence of TMJ disorders, the Research Diagnostic Criteria for Temporomandibular Disorders was employed. This diagnostic tool is widely used in clinical and research settings to assess TMJ-related pain and dysfunction. Results: The agreement was excellent, according to the intra-observer and inter-observer correlation values obtained. There was no statistically significant difference between the two groups in terms of age and gender distribution. The results showed that the anterior and posterior joint spaces were significantly higher in the symptomatic group compared to the asymptomatic group. However, there was no statistically significant difference between the two groups in terms of superior joint space and articular eminence inclination values. Gender did not create a significant difference in any parameter. Conclusion: The results of this study emphasize that CBCT images have an important role in detecting significant changes in condyle position in patients with TMJ disorders. However, further large-scale studies are necessary to validate and enhance the findings.

Comparative Evaluation of the Horizontal Condylar Guidance Using Protrusive Interocclusal Records, OPG, and CBCT in Edentulous Patients: An In Vivo Study.

A clinical study to compare the horizontal condylar guidance using protrusive interocclusal records, orthopantomography (OPG), and cone-beam computed tomography (CBCT) in edentulous patients. Thirty-six edentulous subjects were selected as per predetermined criteria. Horizontal condylar guidance was recorded using protrusive interocclusal records (PIR), OPG, and CBCT for each patient. The PIR were obtained using extraoral Gothic arch tracers to program the Hanau articulator. The horizontal condylar guidance angles (HCGAs) were digitally constructed using appropriate software along the posterior slope of articular eminence for all radiographs. The collected data were recorded, tabulated, and statistically analyzed. The condylar guidance angle values were tested for significance to compare the different angles. The correlation of HCGA measurements on both sides between the three groups was analyzed. The PIR and OPG methods (p = 0.001), as well as the OPG and CBCT methods (p = 0.001), show substantial differences on both sides. On the contrary, the PIR and CBCT methods did not differ significantly (p = 0.11). Cone-beam computed tomography is as reliable and accurate as the clinical method. A significant correlation exists between the clinical method and CBCT. It can be used as a dependable adjunct to the clinical method of HCGA measurement. Cone-beam computed tomography can overcome the shortcomings of the conventional clinical methods to determine the accurate horizontal condylar guidance angulation measurement. It is safer with minimum discomfort and wastage of time for the patients.

Application of the theory of equal emphasis on muscle and bone in percutaneous vertebroplasty of lumbar osteoporotic compression fracture

To explore the clinical efficacy of percutaneous vertebroplasty(PVP) combined with nerve block in the treatment of lumbar osteoporotic vertebral compression fractures under the guidance of traditional chinese medicine "theory of equal emphasis on muscle and bone". Total of 115 patients with lumbar osteoporotic vertebral compression fractures were treated by percutaneous vertebroplasty from January 2015 to March 2022, including 51 males and 64 females, aged 25 to 86 (60.5±15.9) years. Among them, 48 cases were treated with PVP operation combined with erector spinae block and joint block of the injured vertebral articular eminence (intervention group), and 67 cases were treated with conventional PVP operation (control group). The visual analogue scale(VAS) and Oswestry disability index(ODI) before operation, 3 days, 1 month and 6 months after operation between two groups were evaluated. The operation time, number of punctures and intraoperative bleeding between two groups were compared. The VAS and ODI scores of both groups improved significantly after operation compared with those before operation(P<0.05). Moreover, the VAS and ODI scores of 3 days and 1 month after operation of the intervention group improved more significantly than that of the control group(P<0.05). The difference of VAS and ODI scores before operation and 6 months after operation between two groups had no statistical significances(P>0.05). There was no statistically significant difference in the number of punctures and intraoperative bleeding between the two groups (P>0.05). Based on the theory of "equal emphasis on muscles and bones", PVP combined with nerve block can effectively relieve paravertebral soft tissue spasm and other "muscle injuries", which can significantly improve short-term postoperative low back pain and lumbar spine mobility compared to conventional PVP treatment, and accelerate postoperative recovery, resulting in satisfactory clinical outcomes.

Comparative evaulation of condylar guidance obtained by digital panoramic radiographic images with that of obtained during jaw relation and try-in using two different interocclusal record material in completely edentulous patients: an in vivo study

Background: In completely edentulous patients, maintaining the patient's TMJ health and intraoral components is very important. This can be achieved by an accurate interocclusal record, which can we taken by various materials and also at various stages. Simulation of the temparomandibular joint anatomy and mandibular movements is possible on a semi adjustable articulator which is use widely in prosthodontics. Transferring the record on articulator is a critical step in fabrication of complete dentures so it should be done precisely to reduce chair side time and also to avoid complications for patients. This study examines which material is more accurate and also records which stage gives more precision, by comparing the Condylar guidance on radiographs. This is because it has consistent bony landmarks and is comparable to clinical methods in terms of standardisation. The objective will be to determine the inter occlusal records created during Jaw Relation stage and Try-in using reinforced wax and Polyvinyl siloxane and compare these values to the condylar guidance obtained by OPG. Methods: Recording the Condylar Guidance value on OPG, obtained with tracing Glenoid fossa, Articular eminence and the Frankfurt Horizontal Plane. Followed with conventional steps in making complete dentures, at jaw relation and try-in stage. we will record values of condylar guidance with the two different Interocclusal record materials. Expected result: It will help the clinicians to get knowledge about obtaining precise condylar inclination angle by using right interocclusal record materials. Conclusions: This study will help us to obtain condylar inclination which inturn helps the patients satisfaction as it maintains the patient's TMJ health and intraoral components.

Communication between the temporomandibular joint articular space and the extradural space in patients with temporal bone pneumatization: implications for temporomandibular joint surgery

The pneumatization of the articular portion of the temporal bone is an anatomical variant that can modify the barrier between the articular space and the middle cranial fossa. Thus, this study aimed to identify the presence and degree of pneumatization, as well as the existence of pneumatic cell dehiscence towards the extradural or articular space determining whether it could lead to direct communication between the articular and extradural spaces. Hence, One-hundred skull computed tomography images were selected. The presence and extension of pneumatization were classified according to scores 0, 1, 2, and 3. Dehiscence towards extradural and articular spaces was recorded. In total, 200 TMJ from 100 patients were assessed and 40.5% of pneumatization cases were observed. The most prevalent score was 0 (restricted to the mastoid process), while the least prevalent score was 3 (extending beyond the crest of articular eminence). Dehiscence of the pneumatic cells towards the extradural space is more common than towards the articular space. One complete communication between the extradural and articular spaces was observed. Considering the results, it was concluded that to avoid neurological and ontological complications, awareness of the potential anatomical communications between articular and extradural spaces, particularly in patients with extensive pneumatisation, is necessary.

Characterization of the Temporomandibular Joint Disc Complex in the Yucatan Minipig.

The temporomandibular joint (TMJ) disc complex (i.e., the TMJ disc and its six attachments) is crucial to everyday functions such as mastication and speaking. The TMJ can be afflicted by many conditions, including disc displacement and defects. Pathologies of the TMJ disc complex most commonly present first as anterior disc displacement, which the field hypothesizes may implicate the two posterior attachments. As a result of anterior disc displacement, defects may develop in the lateral disc complex. Tissue engineering is poised to improve treatment paradigms for these indications of the TMJ disc complex by engineering biomimetic implants, but, first, gold-standard design criteria for such implants should be established through characterization studies. This study's objective was to characterize the structural, mechanical, biochemical, and crosslinking differences among the two posterior attachments and the lateral disc in the Yucatan minipig, a well-accepted TMJ animal model. In tension, it was found that the posterior inferior attachment (PIA) was significantly stiffer and stronger by 2.13 and 2.30 times, respectively, than the posterior superior attachment (PSA). It was found that collagen in both attachments was primarily aligned mediolaterally; however, the lateral disc was much more aligned and anisotropic than either attachment. Among the three locations, the PSA exhibited the greatest degree of heterogeneity and highest proportion of fat vacuoles. The PIA and lateral disc were 1.93 and 1.91 times more collagenous, respectively, by dry weight (DW) than the PSA. The PIA also exhibited 1.78 times higher crosslinking per DW than the PSA. Glycosaminoglycan per DW was significantly higher in the lateral disc by 1.48 and 5.39 times than the PIA and PSA, respectively. Together, these results establish design criteria for tissue-engineering of the TMJ disc complex and indicate that the attachments are less fibrocartilaginous than the disc, while still significantly contributing to the mechanical stability of the TMJ disc complex during articulation. These results also support the biomechanical function of the PIA and PSA, suggesting that the stiffer PIA anchors the disc to the mandibular condyle during articulation, while the softer PSA serves to allow translation over the articular eminence. Impact Statement Characterization of the temporomandibular joint (TMJ) disc complex (i.e., the disc and its attachments) has important implications for those aiming to tissue-engineer functional replacements and can help elucidate its biomechanical function. For example, the findings shown here suggest that the stiffer posterior inferior attachment anchors the disc during articulation, while the softer posterior superior attachment allows translation over the articular eminence.

Pneumatization of the articular eminence in cone-beam computed tomography: prevalence and characteristics - literature review.

The articular tubercle is a site prone to pneumatization within the cranial bones. Knowledge of the anatomical variations of pneumatization adjacent to the temporomandibular joint (TMJ) is an important issue. Air cells exhibit decreased resistance to trauma, facilitate the spread of various pathologies in the TMJ, such as inflammation, tumours or fractures. Articular tubercle pneumatization may cause complications during TMJ surgery. Information of possible location allows to detect and conduct differential diagnosis of pneumatization of the articular tubercle (PAT) during cone-beam computed tomography (CBCT) examinations. The aim of this study is to determine the prevalence and characteristics of PAT, with respect to age, gender, location and type through assessment in CBCT images. Articles were selected through database search (PubMed, Scopus, Google Scholar), in which the main objective was to assess the prevalence of articular tubercle pneumatization using CBCT. Search strategies included the following keywords: "pneumatized articular eminence" and "CBCT", "pneumatized articular tubercle" and "CBCT" and "zygomatic air cell defect" and "CBCT". A meta-analysis of prevalence using a random effects model was performed. Fifteen studies met the selection criteria. The results showed that an overall prevalence of articular tubercle pneumatization was 25.22% (n = 6393; 95% confidence interval [CI] 15.84-35.94). The occurrence of PAT in females was 25.14% (n = 3064; 95% CI 14.96-36.94). The frequency of PAT in males was 25.81% (n = 2671; 95% CI 15.30-37.99). There was no correlation between the frequency, location or type of PAT with age and gender.

Is magnetic resonance imaging or cone beam computed tomography alone adequate for the radiological diagnosis of symptomatic temporomandibular joint osteoarthritis? A retrospective study

This study was performed to compare the diagnostic accuracy of cone beam computed tomography (CBCT) alone and magnetic resonance imaging (MRI) alone in patients with clinical symptoms of temporomandibular joint osteoarthritis (TMJ-OA). Fifty-two patients (83 joints) with clinical signs of TMJ-OA were included in the study. Two examiners evaluated CBCT and MRI images. McNemar and kappa tests and Spearman’s correlation analysis were applied. Radiological findings of TMJ-OA were detected in all 83 joints on CBCT or MRI . Seventy-four joints (89.2%) were positive for degenerative osseous changes on CBCT. MRI findings were positive in 50 joints (60.2%). Osseous changes were found in 22 joints, joint effusion in 30 joints, and disc perforation/degeneration in 11 joints on MRI. CBCT was more sensitive than MRI in detecting condylar erosion (P = 0.001), osteophyte (P = 0.001), and flattening (P = 0.002) and flattening of the articular eminence (P = 0.013) . Poor agreement (κ = −0.21) and weak correlations were found between CBCT and MRI. The study findings suggest that CBCT is superior to MRI in evaluating osseous changes of TMJ-OA, and that CBCT is more sensitive than MRI in detecting condylar erosion, condylar osteophyte, and flattening of the condyle and articular eminence.

Comparison of Articular Eminence Steepness in Patients With Temporomandibular Joint Disc Disorders

Comparison of Articular Eminence Steepness in Patients With Temporomandibular Joint Disc Disorders

An irrefutable unambiguous insight into zygomatic air cell defect (ZACD)

Zygomatic air cell defect (ZACD) of the temporal bone, has been characterized as the auxiliary air cells in the zygomatic process and articular eminence of the temporal bone. They present as unresectable findings in the zygomatic process of the temporal bone and articular tubercle. They are crucial, as they signify regions of weak resistance and the spread of disease. Comprehension of the decrepit regions in the zygomatic bones with Cone Beam Computed Tomography (CBCT), and the imaging of choice in maxillofacial disorders for its superior 3D anatomical reconstruction and minimal distortion, are indispensable in the diagnosis, treatment planning and placement of endosseous or basal dental implants to elude complications. 154 CBCT images of subjects aged between18 and 70 years with optimal diagnostic quality and area coverage satisfying the selection criteria without the history of maxillofacial fractures, pathologies, anomalies involving the middle one third of the face were analysed. The overall prevalence of ZACD was in 16 (10.4%) subjects, with 9 in females (56.25%) and in 7 males (43.75%). The men-to-women ratio was 1:1.28. It was also revealed that bilateral incidence of ZACD was more common and the prevalence of ZACD the highest 8 (50%) in the age group of 21- 30 years. This study highlights the importance of research on the prevalence of the ZACD on CBCT, which was exiguous in the past, and compares with similar studies done using panoramic radiographs. This study paves the way for more studies employing CBCT to justify the findings we have expressed.

Condylar Size and Position, Comparison among Different Sagittal Skeletal Relationships: A CBCT Study.

To compare the size and spatial position of mandibular condyles among different sagittal skeletal patterns using CBCT imaging. A cross-sectional study. Place and Duration of the Study: Department of Orthodontics, Armed Forces Institute of Dentistry, Rawalpindi, Pakistan, from 20th March 2021 to 4th January 2022. CBCT scans of 66 subjects (33 males, 33 females) were divided into three equal groups on basis of sagittal skeletal relationships (Class I, Class II, and Class III). Condylar size and position were determined using the method described by Hilgers et al. and Ricketts et al. respectively. Independent samples t-test was applied to compare condylar size and position variables between the right and left condyles and between male and female subjects. All study groups were compared using ANOVA and Post Hoc Tukey's test. In males, the condylar size was larger and condyles were slightly more anteriorly positioned. Condylar width and height were smallest in skeletal Class II relation and largest in skeletal Class III relation. Regarding the condylar position, the anterior distance was investigated to be the smallest in Class II. The posterior distance was lesser in skeletal Class I subjects whereas the superior distance was lesser in Class III subjects. Angle of articular eminence was greater in class I, intermediate in class II, and lower in class III. Height of articular eminence was the lowest in Class III subjects. Statistically significant differences existed for the size and position of mandibular condyles among different sagittal skeletal relationships. Temporomandibular joint, Condylar position, Condylar size, Sagittal skeletal relationships, CBCT.

Assessment of mandibular condylar morphology through digital panoramic radiograph: A radiographic study

The temporomandibular joint is one of the most intricate human articulations (TMJ). Each joint is made up of a mandibular condyle and its associated temporal cavity (glenoid fossa and articular eminence). Human mandibular condyle morphology can be divided into six types: Type I: Oval; Type II: Flattened; Type III: Diamond; Type IV: Crooked finger; Type V:Bifid and Type VI: Bird beak. The mandibular condyle appears in several different age groups and individuals in many distinct ways. Condyle remodelling to account for developmental variations, malocclusion, trauma, and other developmental illnesses and diseases are all examples of developmental disorders and diseases that can result from simple developmental variability. Panoramic radiography has been recommended as a screening tool for TMJ patients, and it may be useful to spot major bone abnormalities in the condyle.: The aim of the current study is to observe and record the variations in condyle forms in Punjab (North India) using an Orthopantomographs (OPGs), which were crucial for patient treatment in several branches of dentistry. This retrospective study comprised radiographic evaluation of 400 condylar heads after visualising 200 digitalised OPGs taken for routine investigation. The most common shape of condyle on right observed was oval (43.5%) followed by Bird Beak (20.5%), Diamond (12.5%), Flattened (12%), Crooked finger(6.5%) and Bifid (5%). The most common shape of condyle on left observed was Oval (51%) followed by Bird Beak (15%), Diamond (14%), Flattened (9%), Crooked finger(8%) and Bifid (3%). In Males, the commonest form of left and right condylar morphology was and the least form of right condylar morphology was , whereas the least form of left condylar morphology observed was and In Females, the commonest form of left and right condylar morphology was and the least form of left and right condylar morphology observed was The aim of this study was to determine the most typical radiographic forms of the mandibular condyle on the OPG. Six various condyle shapes—Oval, Flattened, Bird beak, Diamond, Crooked finger, and bifid—have been identified in the current study, with the oval form being the most prevalent on both sides and in both sexes. Bifid is the least typical shape for the right and left condyles.

The variant relationship of the maxillary artery to the lateral pterygoid muscle: a cadaveric study

Study objective: To describe the variations and anatomical landmarks of the maxillary artery Study design and population: This was a descriptive cross-sectional cadaveric study, carried out in the department of human anatomy at the University of Nairobi. Study duration: This was conducted between November 2015 and May 2016. Material and methods: Ninety three (93) hemi-sections from 48 cadavers were used for the study. Dissection of the infratemporal fossa was done to expose the MA and its branches on both sides. The distance of the MA from the articular eminence, mandibular neck, mandibular notch and pterygoid fovea were recorded. The relationship of the MA with the LPM and its branching pattern noted. Results: Out of the 93 hemi-sections dissected 67% of the MA were within the parotid gland while 33% were medial. Thirty five of the MA had a medial relationship to the LPM while, 58 were lateral. Six (6.5%) hemi-sections had the middle meningeal artery (MMA) and the inferior alveolar artery (IAA) originating from a common trunk on the MA. The accessory meningeal artery (AMA) was absent in 3 (3.2%) hemi-sections on the right side and in 2 (2.2%) on the left. Amongst all distances measured of the MA to the bony prominences; mandibular notch, condylar neck, articular eminence, the Pterygoid fovea (14.61±7.07mm for the left and13.93±6.17 and the right side) was the most reliable. Conclusion: The relationship of the MA is more lateral than medial. The most reliable bony landmark is the pterygoid fovea. The branching pattern of the IAA and MMA off the MA is inconsistent in different studies. The MA is a very variable and tortuous artery, probably influenced by age, gender and ethnicity.

Cone-beam computed tomographic characteristics in degenerative temporomandibular joint disease patients with chewing side preference

This study is aimed at assessing the Cone-beam computed tomographic (CBCT) characteristics of temporomandibular joints (TMJ) in degenerative temporomandibular joint disease (DJD) patients with chewing side preference (CSP). CBCT images of 98 patients with DJD (67 with CSP and 31 without CSP) and 22 asymptomatic participants without DJD were measured retrospectively to compare the osteoarthritic changes and the morphology of TMJ. Quantitative analysis of the TMJ radiographic images was performed to present a comparison between the three inter-group groups and between the two sides of the joints. The frequencies of the articular flattening and surface erosion occur more often in the preferred side joints of DJD patients with CSP than the contralateral side. In addition, the horizontal angle of condyle, the depth of glenoid fossa (DGF), and the inclination of articular eminence (IAE) were larger in DJD patients with CSP than that in asymptomatic participants (p<0.05). Also, the condylar anteroposterior dimension of preferred side joints was significantly less than that of non-preferred side (p=0.026), while the width of condyles (p=0.041) and IAE (p=0.045) was greater. DJD patients with CSP appear to have a higher prevalence of osteoarthritic changes, with the morphological changes such as flat condyle, deep glenoid fossa, and steep articular eminence, which might be considered the characteristic imaging features. This study found that CSP is a predisposing factor for the development of DJD, and attention should be paid to the existence of CSP in DJD patients during the clinical practice.

Role of Dynamic 3 Tesla MRI in the Evaluation of Temporomandibular Joint Dysfunction.

The internal derangement of the temporomandibular joint (TMJ) is the most common type of dysfunction. Internal derangement can be divided into anterior and posterior disc displacement. Anterior disc displacement is the most common type, which is further classified into anterior disc displacement with reduction (ADDWR) and without reduction (ADDWoR). Temporomandibular joint dysfunction (TMD) symptoms are pain, reduced mouth opening, and joint sound. The main aim of this study was to correlate the clinical findings and magnetic resonance imaging (MRI) diagnosis of TMD in symptomatic and asymptomatic TMJs. This prospective observational study was conducted in a tertiary care hospital on a 3T Philips Achieva MRI machine with 16-array channel coils after obtaining approval from the institutional ethical committee. A total of 60 TMJs of 30 patients were included in the study. After the clinical examination of each patient, an MRI of both right and left TMJs was done. In patients with unilateral TMD, the asymptomatic side was used as the asymptomatic joint, and the affected side as the symptomatic joint. Asymptomatic patients without any symptoms of TMD were used as controls for bilateral TMD cases. MRI with high-resolution specific serial sections was obtained in both open- and closed-mouth positions. A p-value of <0.05 was considered a statistically significant agreement between clinical and MRI diagnoses of internal derangement. Out of a total of 30 clinically asymptomatic TMJs, only 23 were normal on MRI. On MRI, 26 TMJs showed ADDWRand 11 showed ADDWoR. The most common shape of the disc was biconcave and the displacement was anterior in symptomatic joints. The most common type of articular eminence shape was sigmoid in ADDWR and flattened in ADDWoR. Agreement between clinical and MRI diagnosis in this study was 87.5% (p < 0.001). The study concluded substantial agreement between clinical and MRI diagnosis of TMJ internal dysfunction and suggests that the diagnosis of the internal dysfunction can be made clinically but the exact position, shape, and type of disc displacement can be assessed precisely with the help of MRI.

Evaluation of congruency of condyle convexity and fossa concavity and interrelationship bony components in temporomandibular joint anterior dislocation.

This study aimed to compare the congruency of surface geometry of the articulating bones and morphologic differences in temporomandibular joint (TMJ) structure, between patients with TMJ anterior dislocation and healthy controls. The study included 15 patients with TMJ anterior dislocation and 15 controls who underwent cone-beam computed tomography. The surface angle of the articular fossa (fossa-concavity) and condyle (condyle-convexity) and joint spaces were measured from both sagittal and coronal views. The articular eminence morphology and horizontal condyle position were also evaluated. Coronal fossa angles were significantly lower in controls than in patients (p < 0.05). There was a positive correlation between coronal condyle and fossa angle values in controls and in patients' joints (p < 0.05), however, the fossa-condylar congruence was higher in controls than in patients. Superior joint space was significantly higher in controls than in patients (p < 0.05). There were no significant differences in articular eminence measurements, mean condyle angle variables and condyle position between the patients and controls (p > 0.05). The findings of this study which include lower joint congruency, higher fossa concavity and superior joint space distance in patients with anterior dislocation may be related to the inferior positioning of the condyle away from the fossa and potentially the elongation of the capsular ligament.

A case of osteochondroma arising at the articular tubercle of the temporal bone

Osteochondroma is a benign bone tumor covered by a cartilage cap, arising at the external surface of the bone. In the oral and maxillofacial regions, this lesion is known to develop in the mandibular condyle; however, involvement of the temporal bone is rare. We present a case of osteochondroma arising at the articular tubercle of the temporal bone. A 32-year-old man visited our department for evaluation of a mass in the right temporal bone. Radiographic examination revealed a pedunculated exophytic mass continuous with the articular tubercle of the right temporal bone, and the patient was clinically diagnosed with a temporal bone tumor. We performed surgical resection through a preauricular incision under general anesthesia. A histopathological evaluation revealed formation of bone covered by a cartilage cap, which confirmed the diagnosis of osteochondroma. The residual lesion showed no growth two years postoperatively.