No abstract

The frequency of the lingual foramina in the medial region was 100% and that in the lateral region was 80%. It would also be useful to emphasize the significant variation in the precise location of these lingual foramina, and that these can only be visualized presurgically with volumetric imaging modalities, such as CT or Cone beam 3D systems.

Logicon Caries Detector (LDDC) is the only commercially available computer-assisted diagnostic system for caries diagnosis. The object of this study is to elucidate the efficacy of LDDC when used by inexperienced dentists. Fifty extracted teeth were imaged using an RVG6000. Seven dentists who had just passed the Japanese National Dental Board Examination observed those images without LDDC (woLDDC) and assessed the probability that caries lesions were present, then re-assessed the same teeth using LDDC (wLDDC). The areas under the receiver operating characteristic curves (Az) were compared. No statistically significant difference was found between woLDDC Az values and wLDDC Az values when caries lesions of all depths were considered. When positive cases were restricted to caries lesions in the inner half of the enamel or to dentine caries lesions, however, wLDDC Az values were significantly larger than woLDDC (p = 0.043 and 0.018, respectively).

No abstract

A substantial number of subjects presented with accessory foramina on the lingual posterior aspect when compared to other aspects. Nevertheless, the number of subjects with accessory foramina on other aspects of the mandible was considerable and cannot be ignored. It is suggested that when an accessory foramen is identified in an individual on a particular aspect of the mandibular body, it is highly probable that he will exhibit accessory foramina on other aspects as well.

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Objective To evaluate the utility of the X-ray attenuation coefficient as a measure for quantifying the radiopacity of restorative resins at different exposure times and film speeds. Materials and methods Five restorative resins were made into disks, measuring 10 mm in diameter with thicknesses of 0.5, 1.0, 1.5, 2.0, and 2.5 mm. These resin disks, an aluminum step wedge, and a lead disk were placed on size 4 Ultraspeed Ò D and Insight Ò E/F films. X-ray parameters were 65 kVp, 10 mA, and 30-cm focus-to-film distance. Exposure times were 0.3, 0.15, and 0.10 s for the D-speed films and 0.15, 0.10, and 0.05 s for the E/F-speed films. At each exposure setting, three D-and E/F-speed films were exposed and processed immediately with an automatic processor. The optical density was measured with a transmission densitometer. The net optical density (D) was used to calculate the linear attenuation coefficients (l) using lnD = -lx ? lnD 0 , where D and D 0 denote the optical density of the specimen and background, respectively. Results The linear attenuation coefficients (mm -1 ) of the five restorative resins were 0.24-0.27 for Sorare Ò , 0.30-0.34 for Estelite Ò , 0.36-0.39 for Gradia Ò , 0.51-0.54 for Clearfil AP-X Ò , and 0.52-0.56 for Beautifil Ò . These were all higher than that of dentin (0.15-0.19). There was no significant difference in the attenuation coefficients at different exposure times or film speeds. Conclusions Attenuation coefficients can be used instead of aluminum wedges of equivalent thickness to quantify the radiopacity of restorative resins.

The purpose of this study was to compare findings on the relationship between impacted molar roots and the mandibular canal in panoramic and three-dimensional cone-beam CT (CBCT) images to identify those that indicated risk of postoperative paresthesia. The relationship between impacted molars and the mandibular canal was first classified using panoramic images. Only patients in whom the molar roots were either in contact with or superimposed on the canal were evaluated using CBCT. Of 466 patients examined using both panoramic and CBCT images, 280 underwent surgical extraction of an impacted molar, and 15 of these (5%) reported postoperative paresthesia. The spatial relationship between the impacted third molar root and the mandibular canal was determined by examining para-sagittal sections (lingual, buccal, inter-radicular, inferior, and combinations) obtained from the canal to the molar root and establishing the proximity of the canal to the molar root (in contact with or without loss of the cortical border and separate). The results revealed that darkening of the roots with interruption of the mandibular canal on panoramic radiographs and the inter-radicular position of the canal in CBCT images were characteristic findings indicative of risk of postoperative paresthesia. These results suggest that careful surgical intervention is required in patients with the above characteristics.