Tomographic Evaluation of Accessory Canals Penetrating at the Inner Side of the Anterior Region of Mandibles.

BACKGROUND: The anterior region of the mandible is generally considered to be a safe region to invasive procedures; however, on its internal face, uncountable penetrating canals may be encountered. OBJECTIVE: To perform morphometrical and topographical analysis of endosseous canals located at the inner side of the mandibular anterior region, using cone-beam computed tomography. METHODS: Forty-six examinations were digitally analyzed. Localization of canals in relation to the midline, trajectories, communications between other anatomic structures and relation with teeth were evaluated. Longitudinal and transversal diameters of the canals and distances to the lower edge and symphysis of the mandible were also measured. RESULTS: All individuals had at least 1 canal, with a mean of 2.3 and higher prevalence in the midline region. The adjacent teeth to the canals were usually the incisors but the authors could not determine the connected anatomical structure in most patients. Both the mean diameters were quite similar, about 1 mm; however, the trajectories and distances to the lower edge and symphysis of mandible showed a remarkable heterogeneity among the individuals. CONCLUSIONS: These endosseous canals are consistent and clinically relevant findings and should never be underestimated by professionals.

Evaluation of retromolar canals on cone beam computerized tomography scans and digital panoramic radiographs.

PURPOSE: The purpose of this study was to carry out morphologic and topographic analyses of retromolar canals on cone beam computerized tomography (CBCT) scans, comparing findings to others obtained from the corresponding digital panoramic radiographs. METHODS: Sixty-one CBCT scans were analysed digitally, as well as their corresponding digital panoramic radiographs. The prevalence and distribution of these canals, foramen diameters, and intraosseous communications were also evaluated. RESULTS: On CBCT scans, we found that 24.6% of individuals had at least one retromolar canal. The mean foramen diameter was slightly higher than 1 mm and we could not determine the intraosseous anatomical connections in most cases. The morphology and topography of the retromolar canals were not affected by gender and antimere. In addition, only 22.2% of all tomographically identified canals could be confirmed on digital panoramic radiographs (26.7% of such patients). Regarding all sample, 6.6% of individuals showed retromolar canals on digital panoramic radiographs. CONCLUSION: We may consider that these structures are clinically relevant findings and, due to the low accuracy of the panoramic radiographs, high-quality tomographic exams should always be asked for presurgical treatment planning.

Evaluation of protein undernourishment on the condylar process of the Wistar rat mandible correlation with insulin receptor expression.

UNLABELLED: The mandible condylar process cartilage (CP) of Wistar rats is a secondary cartilage and acts as a mandibular growth site. This phenomenon depends on adequate proteins intake and hormone actions, including insulin. OBJECTIVES: The present study evaluated the morphological aspects and the expression of the insulin receptor (IR) in the cartilage of the condylar process (CP) of rats subjected to protein undernourishment. MATERIAL AND METHODS: The nourished group received a 20% casein diet, while the undernourished group (U) received a 5% casein diet. The re-nourished groups, R and RR, were used to assess the effects of re-nutrition during puberty and adulthood, respectively. CPs were processed and stained with picro-sirius red, safranin-O and azocarmine. Scanning electron microscopy and immunohistochemistry were also performed. RESULTS: The area of the CP cartilage and the number of cells in the chondroblastic layer decreased in the U group, as did the thickness of the CP layer in the joint and hypertrophic layer. Renourishment during the pubertal stage, but not during the adult phase, restored these parameters. The cell number was restored when re-nutrition occurred in the pubertal stage, but not in the adult phase. The extracellular matrix also decreased in the U group, but was restored by re-nutrition during the pubertal stage and further increased in the adult phase. IR expression was observed in all CPs, being higher in the chondroblastic and hypertrophic cartilage layers. The lowest expression was found in the U and RR groups. CONCLUSIONS: Protein malnutrition altered the cellularity, the area, and the fibrous cartilage complex, as well as the expression of the IRs.

Evaluation of protein undernourishment on the condylar process of the Wistar rat mandible correlation with insulin receptor expression

The mandible condylar process cartilage (CP) of Wistar rats is a secondary cartilage and acts as a mandibular growth site. This phenomenon depends on adequate proteins intake and hormone actions, including insulin. Objectives The present study evaluated the morphological aspects and the expression of the insulin receptor (IR) in the cartilage of the condylar process (CP) of rats subjected to protein undernourishment. Material and Methods The nourished group received a 20% casein diet, while the undernourished group (U) received a 5% casein diet. The re-nourished groups, R and RR, were used to assess the effects of re-nutrition during puberty and adulthood, respectively. CPs were processed and stained with picro-sirius red, safranin-O and azocarmine. Scanning electron microscopy and immunohistochemistry were also performed. Results The area of the CP cartilage and the number of cells in the chondroblastic layer decreased in the U group, as did the thickness of the CP layer in the joint and hypertrophic layer. Renourishment during the pubertal stage, but not during the adult phase, restored these parameters. The cell number was restored when re-nutrition occurred in the pubertal stage, but not in the adult phase. The extracellular matrix also decreased in the U group, but was restored by re-nutrition during the pubertal stage and further increased in the adult phase. IR expression was observed in all CPs, being higher in the chondroblastic and hypertrophic cartilage layers. The lowest expression was found in the U and RR groups. Conclusions Protein malnutrition altered the cellularity, the area, and the fibrous cartilage complex, as well as the expression of the IRs. .

Avaliação e correlação clínica dos forames da face interna da região anterior de mandíbulas secas humanas / Evaluation and clinical correlation of foramina on the inner side of the anterior region of dry human mandibles

O objetivo deste artigo foi avaliar a incidência e a localização de forames na face interna da região anterior de mandíbulas secas, correlacionando os achados com a prática odontológica. Trezentas e vinte mandíbulas foram analisadas e classificadas de acordo com a ausência total de dentes nesta região. Observou-se a presença de forames em sínfise mandibular e a esqueletopia com as espinhas genianas. Forames fora de linha mediana também foram avaliados. Todos os espécimes possuíram ao menos um forame. Em região de sínfise foram sempre presentes e geralmente dispostos aos pares. Fora de linha mediana, a prevalência foi consideravelmente heterogênea entre grupos, com menor valor médio nas mandíbulas edêntulas. Os forames abordados são achados consistentes e não devem ser subestimados pelo clínico.

This article evaluates incidence and localization of foramina on the inner side of the anterior region of dry mandibles, correlating the findings with the dentistry practice. 320 mandibles have been analyzed and grouped according to total absence of teeth in this region. We have observed the presence of foramina in mandibular symphysis and the skeletopie with genial spines. Foramina out mandibular midline have also been evaluated. All samples have shown at least one foramen. On symphysis region, foramina have always been present and usually disposed in pairs. Out midline, the prevalence of foramina has been heterogeneous between the groups, it showing a lesser mean value in edentulous mandibles. These foramina are a consistent finding and should never be underestimated by professionals.