Teruaki Muramatsu

Computed Tomography Findings of Mandibular Nutrient Canals

Introduction:The purpose of this study was to assess computed tomography (CT) findings of mandibular nutrient canals using CT images. Materials and Methods:We retrospectively analyzed the mandibular CT images of 194 consecutive patients. For image analysis such as canal prevalence, location, number, size, shape, and the CT value of nutrient foramina were determined using CT axial images of 0.5 and 3 mm slice thickness. Results:We revealed that the nutrient canals were seen 94.3% in the mandible, mostly seen in the anterior region. By location, nutrient canals were particularly seen between the central and lateral incisors. The mean number of nutrient canals was 2.7. The mean diameter of the nutrient foramen between the central and lateral incisors was 1.0 mm. In about 80% of the cases, foramina between the central and lateral incisors were ovoid. The mean CT value for the nutrient foramina between the central and lateral incisors was 411 HU. Discussion and Conclusions:Mandibular nutrient canals were ovoid shape, and the mean CT value was 411 HU. By preoperative knowledge of the position and anatomy of the mandibular nutrient canals, complications such as injury to the nutrient canals can be avoided.

Parotid Lymphadenopathy Is Associated With Joint Effusion in Non-Neoplastic Temporomandibular Disorders

PURPOSE Lymphadenopathy often occurs in the setting of inflammation, with or without infection. We sought to elucidate any association of parotid lymphadenopathy with joint effusion in temporomandibular joint (TMJ) disorders. MATERIALS AND METHODS We performed a retrospective cohort study. We analyzed the magnetic resonance imaging studies of patients with suspected TMJ disorders performed from April 2006 to March 2007. The degree of joint effusion was graded on sagittal T2-weighted spin echo images according to a commonly used system. On axial short T1-weighted short inversion recovery images, the number and short-axis diameter of the parotid lymph nodes were recorded. We performed analyses of the cluster-correlated data using the Mann-Whitney U test and Spearmans correlation coefficients. P < .05 was considered to indicate significance. To assess the possible predictive value of certain variables, a generalized linear model (generalized estimation equation) was constructed, considering the multiple measurements. RESULTS A total of 402 TMJ disorders were analyzed from 201 patients during the study period. The number and size of the parotid lymph nodes identified was significantly greater in the patients with TMJ effusion (P < .01) than in those without effusion. CONCLUSION In the present study, we found an association between parotid lymphadenopathy and joint effusion in TMJ disorders. These findings indicate that lymphadenopathy should be considered as an inflammation condition commonly associated with joint effusion in TMJ disorders.