It is important to know the position of the mental foramen for the placement of osseointegrated implants in the mandibular premolar region. The position of the mental foramen of Koreans is closer to the cusp tips of lower premolars than Westerners.

PurposeThis study aimed to provide comparative measurements of the effective dose from direct and indirect digital panoramic units according to phantoms and exposure parameters.Materials and MethodsDose measurements were carried out using a head phantom representing an average man (175 cm tall, 73.5 kg male) and a limbless whole body phantom representing an average woman (155 cm tall, 50 kg female). Lithium fluoride thermoluminescent dosimeter (TLD) chips were used for the dosimeter. Two direct and 2 indirect digital panoramic units were evaluated in this study. Effective doses were derived using 2007 International Commission on Radiological Protection (ICRP) recommendations.ResultsThe effective doses of the 4 digital panoramic units ranged between 8.9 µSv and 37.8 µSv. By using the head phantom, the effective doses from the direct digital panoramic units (37.8 µSv, 27.6 µSv) were higher than those from the indirect units (8.9 µSv, 15.9 µSv). The same panoramic unit showed the difference in effective doses according to the gender of the phantom, numbers and locations of TLDs, and kVp.ConclusionTo reasonably assess the radiation risk from various dental radiographic units, the effective doses should be obtained with the same numbers and locations of TLDs, and with standard hospital exposure. After that, it is necessary to survey the effective doses from various dental radiographic units according to the gender with the corresponding phantom.

Secretory leukocyte protease inhibitor (SLPI) plays an important role in promoting the invasion and metastasis of a range of cancer cells. However, there are no reports of the expression and function of SLPI in oral carcinoma cells. In this study, the oral carcinoma cell line KB was used to determine whether SLPI affects the proliferation, migration and invasion of oral carcinoma cells. RT-PCR and Western blotting revealed high levels of endogenous SLPI expression in KB cells as well as a strong increase in SLPI secretion after wounding compared to immortalized normal oral keratinocytes (INOK). The wound healing assay revealed more migration of KB cells than INOK cells, and the SLPI treatment increased the migration of KB cells. KB cell proliferation was increased significantly by the SLPI protein but decreased by SLPI-siRNA. SLPI strongly increased the migration and invasion of KB cells. On the other hand, SLPI-siRNA decreased the migration and invasion of KB cells. This suggests that SLPI plays an important role in the metastasis of oral carcinoma cells.

A 40-year-old man suffered from a repeatedly recurrent desmoplastic ameloblastoma in the right maxillary anterior and premolar regions. During the first visit, the patient was provisionally histopathologically diagnosed with a developmental cyst, and it was confirmed to be unicystic ameloblastoma and resected. Four years later, the lesion recurred, and was diagnosed as a desmoplastic type of ameloblastoma and removed again. Then, 5 years after the second surgery, the lesion recurred again, and was diagnosed as a type containing a follicular pattern, recurrent ameloblastoma. A panoramic radiograph showed a multilocular and mixed radiolucent/radiopaque expansile lesion at the first visit, a unilocular cystic lesion confined to the premolar area at the second visit, and a small soap bubble appearance in the molar area in the final visit. Cone-beam computed tomographic images of the final recurrence of the tumor revealed multiple small cyst-like structures in the right maxillary anterior and posterior regions.

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