Quantitative analysis of periapical lesions on cone beam computed tomograph and periapical radiograph / 대한구강악안면방사선학회지

PURPOSE: To detect the progression of experimentally induced periapical lesions on periapical radiograph and cone beam computed tomograph (CBCT) by quantitative analysis. MATERIALS AND METHODS: After the removal of coronal pulps from premolars of two Beagle dogs, the root canals of premolars were exposed to oral environment during one week and then sealed for 70 days. Digital periapical radiographs and CBCTs were taken at baseline and every 7 days for 77 days after pulp exposure. We examined occurrence and areas of periapical bone resorption. Three comparative groups of CBCT radiographs were prepared by average projection of thin slabs with different bucco-lingual thicknesses (0.1, 3.0, and 8.0 mm) using a 3D visualization software. Radiographic densities were compensated by image normalization. Digital images were processed with mathematical morphology operations. The radiographic density and morphological features of periapical lesions were compared among three groups of CBCT in different time points. RESULTS: In the CBCT group with 0.1 mm thickness, radiographic density (p<0.05) and trabecular bone area (p<0.01) were significantly decreased at the fifth week. However, in the CBCT groups with 3 mm and 8 mm thickness and periapical radiographs, none of densitometric and morphological features showed any significant differences in different time points. Radiographic density of periapical lesion showed increasing tendency at the eleventh week after pulp exposure. CONCLUSION: Radiographic detection of periapical lesions was possible at the fifth week after pulp contamination by quantitative method and was affected by buccolingual bone thickness.

Recurrent unicystic ameloblastoma in mandibular anterior teeth area / 대한구강악안면방사선학회지

The unicystic ameloblastoma (UA) is a variant of the solid or multicystic ameloblastoma, a less encountered variant of the ameloblastoma. It appears more frequently in the second or third decade with no sexual or racial predilection. It is almost exclusively encountered asymptomatically in the posterior mandible. We report a case of a 43-year old patient with UA, who had previously undergone a surgical treatment on the same site about 1 year ago, this lesion recurred and presented as an exophytic gingival lesion in the anterior mandibular region.

Effect of disc displacement on the bony change and disc configuration of TMJ / 대한구강악안면방사선학회지

PURPOSE: The objective of this study was to investigate the effect of TMJ disc displacement on the TMJ disc configuration and surrounding osseous structure. MATERIALS AND METHODS: The proton density and T2-weighted MR images of 57 TMJs were retrospectively studied. These TMJs were divided into three groups according to the anterior disc displacement status on MR sagittal images, those were the normal, anterior disc displacement with reduction (ADWR), anterior disc displacement without reduction (ADWOR). The frequency of disc configuration and surrounding bony change, the border status between articular disc and retrodiscal tissue were investigated according to the positional change of articular disc. RESULTS: There were significant statistical differences of chi-square statistics of TMJ disc configurational type between normal and ADWR/ADWOR group, respectively. Surrounding bony change frequently appeared in ADWOR and a statistically significant difference of chi-square statistics of bony change frequency between normal and ADWOR group was observed. CONCLUSION: These results suggested that the disc configuration and bony change of TMJ are strongly related to TMJ disc displacement.

Recurrent odontogenic keratocysts in basal cell nevus syndrome: Report of a case / 대한구강악안면방사선학회지

Basal cell nevus syndrome (BCNS) is principally characterized by cutaneous basal cell carcinomas, multiple odontogenic keratocysts and skeletal abnormalities. Our patient represented several characteristics of BCNS, such as, multiple odontogenic keratocysts, facial nevus, calcification of falx cerebri, parietal bossing and mental retardation. The cyst on posterior mandible showed recurrent and newly developing tendency.