Radiographic assessment of the mandibular retromolar canal using cone-beam computed tomography.

OBJECTIVE: The 'retromolar' nerve is a collateral branch of the inferior alveolar nerve. Cone-beam computed tomography (CBCT) provides higher resolution images. This CBCT study reports the frequency of the retromolar nerve. MATERIALS AND METHODS: From 2007-2010 the CBCT study of 233 hemi-mandibles have been examined. The CBCT study was obtained from an investigation of the posterior mandibular region in 187 patients suffering from different pathologies and it was aimed at detecting in patients the presence of a retromolar canal and foramen. RESULTS: Thirty-four retromolar canals with a foramen were detected on 233 CBCT (14.6%) in 30 out of 187 patients (16%). In the 46 patients who underwent CBCT bilaterally, the retromolar canal was found in nine subjects (19.6%) and was present bilaterally in four subjects, for an incidence of 8.7%. CONCLUSIONS: The results suggest that the radiological frequency of the retromolar nerve is notable, with a possible relevance in the surgical approach of the mandibular retromolar area. The presence of a retromolar canal, well detected with CBCT, may warn clinicians about the possibility of inadequate pre-surgical anaesthesia, local intra-operative bleeding and post-operative alterations of the sensation in the third molar area.

Combined orthodontic - mucogingival treatment of a deep post-orthodontic gingival recession.

In this article, the interdisciplinary management of an isolated-type recession defect in a severely compromised mandibular incisor of a young post-orthodontic patient is described. The prognosis of root coverage surgery was very questionable and unpredictable due to the severe root malposition (III Miller class gingival recession). The treatment plan consisted of: (1) interproximal enamel reduction to gain space within the dental arch, (2) orthodontic repositioning of the root of the affected tooth within the alveolar bone and (3) root coverage mucogingival surgery. Clinical re-evaluation 7 months after fixed orthodontic treatment revealed major improvements in the root coverage prognosis due to the resolution of root malposition and de novo formation of keratinized tissue apical to the root exposure (I Miller class gingival recession). A subepithelial connective tissue graft was performed as a root coverage surgical procedure. Clinical examination 1 year after surgery revealed complete root coverage, good color blending with adjacent soft tissue and an increase in facial gingival thickness. Successful periodontal and esthetic outcomes can be accomplished after the combined orthodontic-periodontal treatment of a severely mucogingivally compromised tooth.

Accuracy of computerized tomography for the evaluation of mandibular sites prior to implant placement.

The objective of the present study was to observe the effect of positioning of the mandible on the accuracy of cross-sectional images obtained by reformatting computerized tomographic (CT) scans. An additional aim was to evaluate the ability of a software program (DentalVox, Era Scientific) to reconstruct these measurements on the reformatted images, regardless of the positioning of the mandible, accurately and without distortion. The test was carried out by examining a partially edentulous dry human mandible with an acrylic radiologic template. Through the use of an acrylic glass support, the mandible was positioned at angles of 0, 10, 15, 20, and 30 degrees relative to the scanning gantry, and a series of CT scans was performed that provided five sets of axial images. Each set of original axial images was reformatted by the DentalVox software, used first in its basic function, which is typical of all software for axial CT measurement (control group), and again in its function of site-specific multiplanar reconstruction (test group). The results showed that the position of the mandible in relation to the CT gantry can influence the precision of the linear measurements. The error ranged from 2% to 51%. The DentalVox software allowed the reconstruction of cross-sectional images with very little distortion regardless of the mandibular position.

Contribution to the radiological study of the eosinophilic granuloma of the mandible (unifocal granuloma due to Langerhans' cell histiocytosis).

PURPOSE: The radiological diagnosis of osteolytic lesions of the mandible still constitutes a challenge in some pathological conditions in which the clinical data and the case history are relatively uniform and the radiological picture is lacking in any characteristics. MATERIALS AND METHODS: We reviewed the conventional radiograms of six cases of Langerhans' cell histiocytosis (LCH) of the mandible examined over the last ten years. The X-ray examinations were performed in the lateral-oblique projection to allow a view of the horizontal portion of the mandible almost completely free of overlapping images of other bone structures. RESULTS: We identified a series of radiological patterns for these reticulo-endotheliopathies capable of causing granuloma formed by polynuclear eosinophils, plasma cells, lymphocytes, and large mononuclear macrophages with granulopexic and phagocytic activity that proliferate in the bone tissue and can be identified as the Langerhans' cells of skin, mucosa, periodontal cavities and bone marrow. The granulomatous tissue penetrates the affected organ elements and, in its spread, it compresses, atrophies, and destroys the damaged tissue, replacing it. The alterations produced by Langerhans' cell histiocytic granuloma are most common in the skeletal system affecting, in order of frequency, the skull, the long bones of the limbs, the foot, the ribs and the spine. The oral mucosa is rarely involved. CONCLUSIONS: The radiological investigation of unifocal Langerhans' cell histiocytic granuloma of the mandible is essential in the study of perimandibular swelling, although diagnosis is based on biopsy alone. In addition to digital or conventional radiography, other useful examinations are bone scintigraphy, Colour Doppler US, MR and CT, which enables a correct localisation necessary for planning the biopsy and treatment.