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Purpose: The purpose of this anatomic study was to compare the retraction force necessary to expose the mandibular neck in the Risdon and the high cervical anteroparotid transmasseteric (HAT) approaches., Methods: An anatomic study was performed on 18 formalin-embalmed cadavers. We performed a Risdon approach on the left side, and an HAT approach on the right side in all the cases. The subjects were placed in a normative frame and the force necessary to maintain a satisfactory exposure of the condyle was measured with a system of cables, pulleys, and mechanical dynamometer. The statistical comparison between the two sides was carried out using the Wilcoxon signed-rank test for paired series., Results: In all the cases, the region of interest was exposed as in the operating room. In the Risdon approach, the mean force was 32 Newtons (4-47). In the HAT approach, the mean force was 19 Newtons (4-33). The difference was statistically significant (p < 0.001). The age, gender, and duration of conservation had no influence on the retraction force., Conclusion: In the HAT approach, the retraction of the soft tissues was significantly lower than in the Risdon approach. This study gave an additional explanation to the remarkable safety of the HAT approach. Our results were in favor of the generalization of this technique.

Introduction: The position of mandibular foramen is variable at the medial aspect of mandibular ramus. Nevertheless its location is useful for the oral and maxillofacial surgeon in orthognatic surgery, especially in vertical ramus osteotomy (VRO) procedure. The aim of our study is to analyse the position of mandibular foramen in order to provide simple and reliable surgical landmarks., Materials and Methods: A radio-anatomical study was undertaken on normal mandibular panoramic X-ray examinations. Precise reproductions were outlined on tracing paper. Original orthonormal landmark was designed using posterior border of the ramus, mandibular incisure and anterior border of the ramus. All these elements are visible in the patient in VRO. Measurements of the position of mandibular foramen in horizontal and vertical dimensions were then performed with a ruler by two independent observers: l (width of mandibular branch), x (distance between posterior border of the ramus and mandibular foramen), h (height of mandibular branch) and y (distance between sigmoid notch and mandibular ramus). x/l and y/h ratios were calculated in order to minimise magnifications and image distortions due to the imaging process., Results: Forty-six panoramic X-rays were analysed, including 24 male and 22 female specimens (sex-ratio 1.1/1) with the mean-age 21 years. In vertical dimension, y/h ratio was distributed on a gaussian mode with a peak around 0.30-0.35, mandibular foramen was located around the midpoint of the inferior two-thirds and the superior third of the ramus, preferentially under this point. In horizontal dimension, x/l ratio observed the same model with a peak around 0.35; mandibular foramen was located around the midpoint of the anterior two-thirds and the posterior third of the ramus, preferentially in front of this point. Mandibular foramen was situated in the ventral and inferior two-thirds of the ramus without difference according to the side, sex or age., Discussion: Posterior and superior thirds of the ramus constitute a "safety zone" where mandibular foramen is unlikely to be found. This area can be used by the oral and maxillofacial surgeon in vertical ramus osteotomy of the mandible with low inferior alveolar nerve morbidity probability.

Lingual nerve damage complicating oral surgery would sometimes require electrographic exploration. Nevertheless, direct recording of conduction in lingual nerve requires its puncture at the foramen ovale. This method is too dangerous to be practiced routinely in these diagnostic indications. The aim of our study was to assess spatial relationships between lingual nerve and mandibular ramus in the infratemporal fossa using an original technique. Therefore, ten lingual nerves were dissected on five fresh cadavers. All the nerves were catheterized with a 3/0 wire. After meticulous repositioning of the nerve and medial pterygoid muscle reinsertion, CT-scan examinations were performed with planar acquisitions and three-dimensional reconstructions. Localization of lingual nerve in the infratemporal fossa was assessed successively at the level of the sigmoid notch of the mandible, lingula and third molar. At the level of the lingula, lingual nerve was far from the maxillary vessels; mean distance between the nerve and the anterior border of the ramus was 19.6 mm. The posteriorly opened angle between the medial side of the ramus and the line joining the lingual nerve and the anterior border of the ramus measured 17 degrees . According to these findings, we suggest that the lingual nerve might be reached through the intra-oral puncture at the intermaxillary commissure; therefore, we modify the inferior alveolar nerve block technique to propose a safe and reproducible protocol likely to be performed routinely as electrographic exploration of the lingual nerve. What is more, this original study protocol provided interesting educational materials and could be developed for the conception of realistic 3D virtual anatomy supports.

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Copyright of Revue de Stomatologie & de Chirurgie Maxillo-Faciale is the property of Masson SPA and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Primary and metastatic mandibular melanoma are extremely rare. We report the original case of a 55-year-old woman treated 16 years before for a cutaneous melanoma, and now presenting with a huge mandibular amelanotic melanoma. Was it an histologically different mandibular metastasis of the previous cutaneous melanoma, or a metachronous oral amelanotic melanoma? [ABSTRACT FROM AUTHOR]