• Journal of Korean Dental Science
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• v.17 no.1
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• pp.14-35
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• 2024

The temporomandibular joint (TMJ) is one of the most unique joints in the human body that orchestrates complex movements across different orthogonal planes and multiple axes of rotation. Comprising the articular eminence of the temporal bone and the condylar process of the mandible, the TMJ integrates five major ligaments, retrodiscal tissues, nerves, and blood and lymph systems to facilitate its function. Cooperation between the contralateral TMJ and masticatory muscles is essential for coordinated serial dynamic functions. During mouth opening, the TMJ exhibits a hinge movement, followed by gliding. The health of the masticatory system, which is intricately linked to chewing, energy intake, and communication, has become increasingly crucial with advancing age, exerting an impact on oral and systemic health and overall quality of life. For individuals to lead a healthy and pain-free life, a comprehensive understanding of the basic anatomy and functional aspects of the TMJ and masticatory muscles is imperative. Temporomandibular disorders (TMDs) encompass a spectrum of diseases and disorders associated with changes in the structure, function, or physiology of the TMJ and masticatory system. Functional and pathological alterations in the TMJ and masticatory muscles can be visualized using various imaging modalities, such as cone-beam computed tomography, magnetic resonance imaging, and bone scans. An exploration of potential pathophysiological mechanisms related to the TMJ anatomy contributes to a comprehensive understanding of TMD and informs targeted treatment strategies. Hence, this narrative review presents insights into the fundamental functional anatomy of the TMJ and pathological changes that evolve with TMD progression.

• Journal of Korean Dental Science
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• v.12 no.2
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• pp.66-72
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• 2019

Osteochondroma is a bone tumor with cartilaginous growth potential that generally appears near the growth plate of long bones in areas such as hip, knee, and shoulder joints, related to the nature of endochondral ossification and it is known a common benign bone tumor. However, it has been very rare in craniofacial region possibly because craniofacial bone is largely formed by intramembranous ossification. Moreover, reports on the solitary type of osteochondroma in mandibular condyle has been extremely rare. Osteochondroma in mandibular condylar may show various symptoms similar to general temporomandibular joint disorders (TMDs), such as pain in the condylar area during mouth opening, internal derangement, facial asymmetry or posterior open bite. Therefore, it can be disregarded for a long time period without any adequate treatment. Surgical excision has been the treatment option for the solitary osteochondroma with very low recurrence rate reportedly. In this case report, a rare case of solitary osteochondroma developed in unilateral mandibular condyle is presented with emphasis on differential diagnosis with general TMDs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.5
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• pp.259-266
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• 2022

The relationship between obstructive sleep apnea (OSA) and diverse types of pain conditions have been proposed. However, no consensus on the relationship between OSA and painful temporomandibular disorders (TMDs) has been established. Therefore, this systematic review has been conducted to review the existing literatures and provide comprehensive synthesis of such literatures about OSA and painful TMDs using the evidence-based methodology. A literature search was conducted using two electronic databases, Scopus, and PubMed. Risk of bias was assessed using the risk-of-bias assessment tool for non-randomized study version 2.0. A total of 158 articles were screened from the initial search and eventually, 5 articles were included in this systematic review. One study adopted both the longitudinal prospective cohort and case-control designs and other 4 articles adopted the cross-sectional design. Two studies employed polysomnography (PSG) for the diagnosis of OSA and mentioned the results from the PSG. All cross-sectional studies demonstrated higher OSA prevalence among patients with TMD, and one cohort study suggested OSA as a risk factor for TMD. OSA appears to have potential influences on the development of TMD; however, the role of TMD in the development of OSA remains to be unknown owing to the lack of high-quality evidences.

• Journal of Oral Medicine and Pain
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• v.48 no.3
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• pp.112-117
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• 2023

Coronoid process hyperplasia (CPH) of the mandible is a rare condition in which abnormal elongation of the coronoid process leads to chronic mandibular hypomobility. CPH causes impingement or impedance of the coronoid process on the inner surface of the frontal part of the zygomatic bone during mouth opening. The lack of significant symptoms makes the diagnosis difficult. Its etiology remains inconclusive despite several theories being suggested. In this report, three reviewed cases are presented. All three patients visited our clinic with limited mouth opening as the chief complaint. Standard clinical and radiographic examinations were conducted under the initial impression of temporomandibular disorders (TMDs), and restricted jaw movements were confirmed in all cases. The absence of improved signs and symptoms following conservative treatment for TMDs or the indeterminate plain radiographs required the attending clinicians to consider three-dimensional imagery. Computed tomography revealed bilateral coronoid hyperplasia in all cases and impingement on the zygomatic bone in two of the three cases. After concluding that this condition caused the patients' limited mouth opening, the patients were referred to the Department of Oral and Maxillofacial Surgery for possible bilateral coronoidectomy or coronoidotomy. CPH usually presents no symptoms apart from a progressive reduction of mouth opening over time. Diagnosis is often delayed, and patients may undergo unnecessary treatment procedures. Clinicians should be aware of this condition and exercise caution in the differential diagnosis of patients with chronic mandibular hypomobility.

• Journal of Oral Medicine and Pain
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• v.24 no.4
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• pp.439-453
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• 1999

This study was performed to investigate the masicatory efficiency in patients with temporomandibular disorders (TMDs), especially internal derangement of temporomandibular (TM) joint. For this study, 26 patients after treatment and 33 dental students who had no signs and symptoms of TMDs were selected as the patients group and as the normal group, respectively. Mean treatment duration of the patients was. 5.1 months. Verbal rating scale(VRS) and Visual analogue scale(VAS) were used for recording of subjective symptoms. Treatment index (VAS Ti) derived from VAS was calculated for evaluation of treatment progress and clinical examination was also performed for objective symptoms. BioEGN(Bioresearch Inc., Milwaukee, USA) was used for observation chewing movement pattern on peanut, caramel candy, and gum chewing. Chewing time in second and symptoms after chewing were recorded, and pattern of chewing stroke between in affected side and in contralateral side or between in right in left side were compared, and especially, gum chewing pattern between before and after treatment were also compared in the patients group. The data obtained were analysed by SPSS windows program and the results of this study were as follows : 1. Subjective symptoms evaluated by VAS showed no difference between the two groups, but those by VRS showed slight difference for TM joint pain, head not neck symptoms, and chewing ability. 2. There were no difference at the level of subjective symptoms between the subgroups divided by treatment duration of five months in the patients group. However, value of VAS Ti of pain was higher in subgroup of long treatment duration than that of subgroup of short treatment duration. 3. There were no difference in chewing time for peanut or caramel candy between the two groups, but on caramel candy chewing, the patients group complained slight discomfort after swallowing. Chewing velocity and range of motion on gum chewing after treatment in the patients group showed significant difference and greatly improved compared to those to before treatment, and which were not differ from those of normal subjects. In conclusion, treatment of temporomandibular disorders about for five months would greatly improve chewing ability and movement pattern in most of the patients with TMDs.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.39 no.5
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• pp.231-237
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• 2013

Objectives: This study aims to evaluate the severity and pattern of symptoms exhibited by teenage Korean temporomandibular disorder (TMD) patients. Materials and Methods: Among patients with an association of TMDs, teenage patients (11-19 years) who answered the questionnaire on the research diagnostic criteria for TMD (RDC/TMD) were recruited. Results: The ratio of patients who visited our clinic with a chief complaint of clicking sound (34.5%) or temporomandibular pain (36.6%) at the initial diagnosis (examination) was the highest. In the evaluation of the depression index, 75.8% of the subjects were normal, 12.9% were moderate, and 11.3% were severe. With regard to non-specific physical symptoms (including pain), 66.5% of the subjects were normal, 17.0% were moderate, and 16.5% were severe. Concerning non-specific physical symptoms (excluding pain), 70.6% of the subjects were normal, 14.4% were moderate, and 15.0% were severe. In terms of the graded chronic pain score, high disability (grade III, IV) was found in 9.3% of the subjects. Conclusion: Among teenage TMD patients, a portion have clinical symptoms and experience severe psychological pressure; hence requiring attention and treatment, as well as understanding the psychological pressure and appropriate treatments for dysfunction.

• Imaging Science in Dentistry
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• v.46 no.2
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• pp.127-131
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• 2016

Purpose: This study was performed to compare the condylar position in patients with temporomandibular joint disorders (TMDs) and a normal group by using cone-beam computed tomography (CBCT). Materials and Methods: In the TMD group, 25 patients (5 men and 20 women) were randomly selected among the ones suffering from TMD according to the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). The control group consisted of 25 patients (8 men and 17 women) with normal temporomandibular joints (TMJs) who were referred to the radiology department in order to undergo CBCT scanning for implant treatment in the posterior maxilla. Linear measurements from the superior, anterior, and posterior joint spaces between the condyle and glenoid fossa were made through defined landmarks in the sagittal view. The inclination of articular eminence was also determined. Results: The mean anterior joint space was 2.3 mm in the normal group and 2.8 mm in the TMD group, respectively. The results showed that there was a significant correlation between the superior and posterior joint spaces in both the normal and TMD groups, but it was only in the TMD group that the correlation coefficient among the dimensions of anterior and superior spaces was significant. There was a significant correlation between the inclination of articular eminence and the size of the superior and posterior spaces in the normal group. Conclusion: The average dimension of the anterior joint space was different between the two groups. CBCT could be considered a useful diagnostic imaging modality for TMD patients.

• Journal of Oral Medicine and Pain
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• v.40 no.2
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• pp.72-78
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• 2015

Purpose: The purpose of this research was twofold: to compare the short-term efficacy of once-off education versus repetitive education (RE) of patients suffering from temporomandibular disorders (TMDs) and to determine whether there was any correlation amongst patient demographics, recommendation adherence degree and pain levels. Methods: A total of 848 patients with TMDs were enrolled. The control group consisted of patients who received a standard conservative treatment (STD) over at least 6 visits with education provided only during the first visit. The experimental group consisted of patients who received STD but had also been given RE (STD+RE). The RE was delivered through a standardized self-assessment questionnaire (SAQ) that was completed by the patient during each visit. Pain, which included maximum comfortable opening (MCO) of the mouth and limitation of mouth opening (LOM), was compared between the two groups. Behavior pattern and reported pain level changes in the group who used the SAQ were also analyzed. Results: The LOM was significantly improved in all of the experimental group patients (especially in females under 30 years of age, p<0.05). The MCO was significantly higher in females (p=0.029). All of the patients displayed improvements in their habits following RE, which resulted in a strong correlation with pain reduction. Adhering to the recommendations regarding questions 14 and 15 of the SAQ appeared to have the greatest effect on pain reduction. Conclusions: These results clearly demonstrate that RE is more effective than once-off education for TMD patients who are female or under 30 years of age.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.43 no.6
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• pp.401-406
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• 2017

Objectives: Headache is the most common complaint of patients suffering from temporomandibular joint disorders (TMDs). Thus, temporomandibular joint (TMJ) examinations maybe necessary in patients with headache. Considering the high prevalence of bruxism and TMDs in patients with headache the effects of conservative TMD treatment on headache should be assessed. Materials and Methods: Patients were questioned about headaches in the past three months. Those responding affirmatively to this question were examined for TMD and bruxism. After the examinations, 219 patients remained in the study and received self-management instructions. Patients were requested to modify oral habits except when eating or sleeping. The degree of pain (visual analogue scale), headache disability index (HDI), frequency of headaches (FH) per month and TMD intensity were evaluated. Results: The median levels of pain, HDI, FH, and TMD intensity were 8, 44, 8, and 7, respectively, before modifying oral habits and decreased to 4, 24, 2, and 3, respectively, after intervention. These decreases were statistically significant. Conclusion: Having patients maintain free space between the teeth and relax muscles can be an efficient method to treat headache and TMD, especially when repeated frequently.

• Imaging Science in Dentistry
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• v.42 no.3
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• pp.169-174
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• 2012

Purpose: To investigate the prevalence of osteoarthritic changes and condylar positioning of the temporomandibular joint (TMJ) in Korean children and adolescents with or without temporomandibular disorders (TMDs). Materials and Methods: A total of 101 asymptomatic and 181 symptomatic children and adolescents aged 10 to 18 years old were included in the study. Osteoarthritic changes such as flattening, sclerosis, osteophytes, or erosion, and the parasagittal positioning of the condyle were assessed using cone-beam computed tomography (CBCT) images. Results: The overall prevalence of osteoarthritic changes was higher in symptomatic (26.8%) than in asymptomatic adolescents (9.9%) (p<0.05). In the symptomatic group, the frequency was higher in males (33.3%) than in females (23.0%) (p<0.05). Erosion was the most common change for the symptomatic group (15.6%), whereas sclerosis was the most common change for the asymptomatic group (5.4%). Posterior condylar position was more frequently observed in the symptomatic group (p<0.05). Erosion was more common in the samples with TMJ pain or mouth opening limitations as compared to those without them (p<0.05). Conclusion: This study showed that osteoarthritic changes in TMJ were common in children and adolescents, with a much higher prevalence in symptomatic patients.