Kai-Yuan Fu

Long-term efficacy of botulinum toxin type A for the treatment of habitual dislocation of the temporomandibular joint.

Injection of botulinum toxin type A (BTX-A) into the lateral pterygoid muscles is a recently reported treatment for habitual dislocation of the temporomandibular joint (TMJ). We report five cases of dislocation in elderly patients with neurological or other severe systemic disease, and their successful treatment with one injection of BTX-A into the lateral pterygoid muscles. This is a relatively conservative option. Injection into the muscle is straightforward and can be done in outpatients with few complications. We recommend it as the first choice for patients with habitual dislocation and systemic or neurological diseases, particularly in the elderly.

Condylar subchondral formation of cortical bone in adolescents and young adults

We investigated subchondral formation of cortical bone in the condyles of adolescents and young adults, and looked for age-related and sex-related differences in bony formation with the aid of cone-beam computed tomography data in 1438 subjects aged between 10 and 30 years. The scans were part of the hospitals clinical protocol for patients seeking orthodontic or orthognathic treatment. No patient had signs or symptoms of temporomandibular disorders. Central images of the coronal and sagittal planes of the condyle were acquired and scored. Subchondral formation of cortical bone was seen as a high-density compact linear image, and subjects were classified into complete, partial, and no formation. Subchondral formation of cortical bone was first seen at the ages of 13-14 in boys and 12-13 in girls. Complete cortical bony formation was seen after the age of 22 years for men and 21 for women. We conclude that cortical bone begins to form around the periphery of the condyles during adolescence (12-14 years). A continuous, homogeneous, and compact cortical bony layer is established in young adults by the age of 21-22, indicating full development of the mandibular condyle. The condylar bone developed gradually and was generally fully developed a year earlier in women than men.

Diagnostic accuracy of parotid CT for identifying Sjögren's syndrome

PURPOSE To evaluate the diagnostic accuracy of computed tomography (CT) of the parotid gland for Sjögrens syndrome in comparison with conventional X-ray sialography. METHODS CT scans and X-ray sialography were performed in 34 patients with confirmed Sjögrens syndrome and 22 symptomatic controls without the disease. CT data from 57 asymptomatic controls were included for quantitative analysis. The CT findings of heterogeneity, abnormal diffuse fat tissue deposition, diffuse punctate calcification, swelling or atrophy, nodularity or cystic changes of the parotid gland were analyzed by two independent blinded readers. The correlation between CT and X-ray sialography findings was evaluated. Diagnostic performance and receiver operating characteristics curves were calculated. RESULTS On CT, heterogeneity of the parotid gland was seen in 30/31 (reader 1/reader 2) Sjögrens syndrome patients by the two readers (sensitivity 88.2%/91.2%; specificity 100%/90.9%). Abnormal diffuse fat tissue deposition was seen in 28/28 SS patients by the readers (sensitivity 82.3%/82.3%; specificity 100%/90.9%). Diffuse punctate calcification was seen in 10/12 Sjögrens syndrome patients (sensitivity 29.4%/35.2%; specificity 100%/100%). Stagings of CT findings correlate positively with sialography. The areas under the receiver operating characteristics curves were 0.887 (P=0.000) and 0.908 (P=0.000) for the maximum and standard deviation (SD) of the CT value. CONCLUSIONS Parotid CT is accurate and reliable in the diagnosis of Sjögrens syndrome. Heterogeneity, abnormal diffuse fat tissue deposition, and diffuse punctate calcification are specific for Sjögrens syndrome. CT attenuation analysis is helpful in diagnosis.

Sleep disturbance and psychologic distress: prevalence and risk indicators for temporomandibular disorders in a Chinese population.

AIMS To investigate the prevalence of sleep disturbance and psychologic distress in a population of Chinese patients with temporomandibular disorders (TMD) and whether sleep disturbance and psychologic distress are risk indicators for TMD. METHODS Validated Chinese versions of the Self-Rating Scale of Sleep (SRSS) and Depression, Anxiety and Stress Scales-21 (DASS-21) were used to measure sleep disturbance and psychologic distress of 510 TMD patients with a mean (± SD) age of 31.06 ± 14.40 years. TMD signs/symptoms and sociodemographic data were also collected. The patients were divided into seven diagnostic groups based on the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). For statistical analysis, the patients were subsequently grouped into those with (n = 128) and without (n = 382) myofascial pain. The data were analyzed using chi-square tests, independent-samples t test, as well as stepwise logistic regression at a significance level of P < .05. RESULTS The prevalence of moderate to severe sleep disturbance and psychologic distress was significantly higher in the myofascial pain group than in the non-myofascial pain group (P < .05). Stepwise logistic regression analysis demonstrated that sleep disturbance and anxiety were possible risk indicators for myofascial pain, with odds ratios of 2.41 and 4.10, respectively (P < .05). CONCLUSION The Chinese population of TMD patients frequently reported a disturbed sleep condition and psychologic distress symptoms. Sleep disturbance and psychologic distress symptoms are possible risk indicators for myofascial pain in this population.

Multidetector computerized tomographic fistulography in the evaluation of congenital branchial cleft fistulae and sinuses.

OBJECTIVE The aim of this study was to primarily investigate the usefulness of computerized tomographic (CT) fistulography in the diagnosis and management of branchial cleft fistulae and sinuses. STUDY DESIGN Fifteen patients with confirmed branchial fistulae or sinuses who had undergone CT fistulography were included. The diagnoses were confirmed by clinical, radiologic, or histopathologic examinations. The internal openings, distribution, and neighboring relationship of the lesions presented by CT fistulography were analyzed to evaluate the usefulness in comparison with x-ray fistulography. RESULTS Nine patients were diagnosed with first branchial fistulae or sinuses, 2 with second branchial fistulae, and 4 with third or fourth branchial fistulae. The presence and location of the lesions could be seen on x-ray fistulography. The distribution of the lesions, internal openings, and neighboring relationship with parotid gland, carotid sheath, and submandibular gland could be clearly demonstrated on CT cross-sectional or volume-rendering images. CONCLUSIONS CT fistulography could provide valuable information and benefit surgical planning by demonstrating the courses of branchial anomalies in detail.

Temporomandibular disorders symptoms in Asian adolescents and their association with sleep quality and psychological distress

Objectives: The aim of this study was to investigate the prevalence of temporomandibular disorders (TMD) symptoms and their association with sleep quality and psychological distress in Chinese adolescents. Methods: Five hundred seventy-eight adolescents were enrolled in the study and completed a self-reported TMD symptom questionnaire and socio-demographics survey. Sleep quality and psychological distress were assessed. Descriptive statistics and logistic regression analysis were performed with TMD symptoms as the outcome variable. Results: The prevalence of adolescents with at least one TMD symptom was 61.4%. One-third of subjects experienced disturbed sleep, depression, and stress; 65.2% experienced anxiety. Subjects with TMD symptoms had greater psychological distress and disturbed sleep than those who were symptom-free. Logistic regression analysis showed that sleep disturbance and daytime dysfunction and anxiety were significantly related to TMD symptoms. Discussion: The prevalence of TMD symptoms in Asian adolescents is high. Disturbed sleep and psychological distress are correlated with TMD; thus, a further longitudinal research of the causality is warranted.

Osteonecrosis of the mandibular condyle as a precursor to osteoarthrosis: A case report

Osteonecrosis of the mandibular condyle is a rare condition characterized by a primary subchondral osseous breakdown of the condyle with secondary articular surface collapse. Despite these characteristics, it has proved to be difficult to diagnose. The present case of osteonecrosis of the mandibular condyle was initially diagnosed more than 2 years before. The diagnosis at that time was based on physical examination, plain film radiography, cone-beam computerized tomography, magnetic resonance imaging, and total body scintigraphy. The disease had progressed into severe osteoarthrosis at a 2-year follow-up using cone-beam computerized tomography. This report suggests that osteonecrosis may be a precursor of osteoarthrosis, and cone-beam computerized tomography may provide a sensitive radiographic technique for the diagnosis of osteonecrosis of mandibular condyle.

Unilateral complete articulated ossification and aberrant thickening of the stylohyoid chain

Eagles syndrome is a rare clinical entity associated with craniofacial and cervical pain. It is caused by an elongated or deviated styloid process and/or calcification/ossification of the stylohyoid ligament. Complete ossification and aberrant thickening of the stylohyoid chain is the most unusual manifestation. We report a patient who presented with complaints of foreign body sensation, dysphagia and moderate submandibular pain caused by unilateral complete ossification, abnormal thickening and hypertrophy of the stylohyoid chain. This case was also unique in that histopathological investigation demonstrated mature bone with both compact and cancellous bone as well as bone marrow.

Subarticular, cystlike lesion associated with avascular necrosis of the mandibular condyle: a case report

Little is known about avascular necrosis of the mandibular condyle, which is necrosis of the epiphyseal or subarticular bone secondary to a diminished or disrupted blood supply in the absence of infection. We present a case of a large subarticular cystlike lesion that was found using cone-beam computed tomography (CBCT). There was an absence of osteoarthrosis, and the condylar articular surface was relatively intact. The patients history, physical examination, and magnetic resonance images supported the diagnosis of avascular necrosis of the mandibular condyle. After 4 months of conservative therapy, new bone was observed in the cystlike marrow lesion, and a smooth articular surface was reestablished. Subarticular cystlike lesions without the collapse of the articular surface of mandibular condyles may be an early indicator of avascular necrosis.