Objective: To investigate the frequency and characteristics of the mandibular accessory buccal foramen (ABF) with CT. Methods: A retrospective study was carried out using the CT records of 504 patients referred to the Erciyes University Medical School (Kayseri, Turkey) between 2007 and 2010. Presence, location, diameter, area and number of ABFs and their continuity with mandibular canal and distance to the mental foramen were evaluated using axial, sagittal and threedimensional CT images. Statistical analysis was performed using SPSSH v. 15 (SPSS Inc., Chicago, IL), and t-tests were used for statistical analysis. Results: 14 ABFs were observed in 10 (2%) of 504 patients. The frequency of ABFs was found to be 2.6% in males and 1% in females. The mean distance between the ABF and the mental foramen was 5.0 mm [standard deviation (SD) ¡2.48]. The mean long axis of the ABFs was 1.4 mm (SD ¡0.4) and the mean area of them was 1.5 mm 2 (SD ¡0.8). The mean area of the mental foramen on the side with the ABF was 4.1 mm 2 (SD ¡2.71). Conclusions: This study presents a relatively lower frequency of ABFs than that in the literature. These foramina could have more complex neurovascular structures than was previously thought. Thus, in special cases where a direct surgical exploration during the planned surgery is not indicated, CT or cone beam CT examination to determine the possible presence of ABFs may be indicated.

Stafne bone defects (SBDs) are asymptomatic lingual bone depressions of the lower jaw that are frequently caused by soft tissue inclusion. The common variant of SBDs exists at the third molar region of the mandible below the inferior dental canal and has been mostly diagnosed incidentally during routine radiographic examination. The anterior variant of a SBD (ASBD) is relatively uncommon and is located in the premolar region of the mandible. Sublingual salivary glands are thought to be responsible for ASBDs. However, other structures such as lymphoid or vascular tissues might be associated with ASBDs. In the present report, an ASBD which was mimicking a residual cyst was diagnosed with the aid of a three-dimensional CT scan. ASBDs might be confused with other odontogenic or non-odontogenic pathologies because of their location and lower occurrence rate. Advanced imaging modalities, especially CT scans, are useful to assess such lesions in order to avoid unnecessary surgery.

Objectives: The clinical significance of the existence of a retromolar canal and of its neurovascular content is not yet clear.The aim of the present study was to assess the visibility, diameter and course of the mandibular retromolarcanal (MRC) using cone beam computed tomography (CBCT) scan -had been taken for pre-operative radiographic evaluation of impacted mandibular third molars- compared to panoramic radiographs. Study Design: Subjects eligible for study enrollment were those who underwent preoperative CBCT scan for the extraction of impactedmandibular third molars were determined to be extremely close to the mandibular canal on panoramic radiographs. Radiographs were screened for the presence and course of retromolar canals, and linear measurements. Results: 947hemimandibles in 632 patients were examined.A total of 253 MRCs (144 left, 109 right) were detected with CBCT images (26.7%). Only 29 of these canals were also seen on the corresponding panoramic radiographs. Most MRCs had a vertical course (type VI, 28.46%), followed by slightly curved (type I, 26.09%). The visibility of the MRC on the OPGs, according to the increase in the diameter, was not statistically significant for both sides (p>.05).Statistically difference were found for the width at the point of origin from the mandibular canal (p: .037), the mean distance from the MRC to the second molar (p: .042) and height of MRC when compared the gender. Conclusions: The findings suggest that the MRC isn’t a rare anatomical structure. This study therefore clearly establishes the incidence and importance of the MRC. The detection of the presence of the MRC using CBCT may be crucial for extraction of mandibular third molars. Key words:Accessory innervation, cone beam computed tomography, mandibular anatomy, panoramic radiographs, retromolar canal, retromolar foramen.

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