SUMMARY:The mandibular foramen and its lingula is a major landmark when administering anesthetic or performing surgical procedures. The objective of this study was to determine whether the topological features of the mandibular foramen (MF) and lingula varied in mandibles from skulls of different cephalic indexes. The location of the mandibular foramen referred to the longitudinal borders of the mandibular ramus (MR), height of the foramen (Hf) referred to the occlusal line of the second molar, and the height of the lingula (Hl) were determined in a total of one hundred and five dry mandibles from skulls identified as dolicho-meso-and brachycephalic. On average MF in brachycephalic mandibles was closest to the anterior border of MR. Hf in brachy-, meso-and dolichocephalic mandibles were -0.22 mm, -4.04 mm and -4,01mm, respectively. The lingula in brachycephalic specimens was considerably shorter (0.78 mm) than in dolichocephalic ones (1.84 mm). Inferior alveolar nerve block should be carried out using shorter needles, inserting it 4mm above the occlusion level of the molar teeth. The ramus of brachicephalic mandibles were significantly less wide those of dolicho-and mesocephalic ones. If the height of the lingula is to be used as a reference to judge the level of the medial horizontal cut to carry out sagittal split ramus osteotomy, special attention should be given to the patient's cephalic index.

INTRODUÇÃO: A mandíbula é um dos ossos da face mais susceptíveis à fraturas e deformidades, tratados através de procedimentos cirúrgicos. Na técnica de osteotomia sagital do ramo mandibular (OSRM) o corte horizontal é feito na face medial do ramo imediatamente acima da língula. OBJETIVO: O propósito desse estudo foi verifi car a existência de correlação da altura e largura do ramo em relação ao gênero e índice cefálico. MATERIAL E MÉTODO: Foram utilizadas 48 mandíbulas humanas dentadas de adultos do tipo dolico (16), meso (16) e braquicefálico (16). Os pontos pré determinados utilizados como referências anatômicas no ramo para mensurações foram: (I) ponto mais inferior da incisura mandibular, (B) ponto mais alto da margem inferior, (A) ponto mais posterior da margem anterior (A) e (P) ponto mais anterior da margem posterior. RESULTADOS: A média da altura e largura do ramo mandibular não apresentou diferença na comparação entre os índices cefálicos (dolico - 47,05 / 32,09mm; meso - 47,27 / 32,57mm; braquicefálico - 46,41 / 29,58mm). Na comparação das dimensões com o gênero, a diferença encontrada foi a altura do ramo no sexo masculino (49,08mm), maior do que no feminino (42,76mm). CONCLUSÕES: Os resultados aqui encontrados podem ser utilizados como referência em procedimentos cirúrgicos do ramo mandibular, investigações forenses e estudos de comparação a dados obtidos em espécimes de outras nacionalidades.

INTRODUCTION: The jaw is one of the facial bone most susceptible to fracture and deformities that must be treated with surgical procedures. On the sagittal split osteotomy of mandibular ramus technique (SSOMR) the horizontal cut is done on ramus medial aspect immediately above the lingula. OBJECTIVE: The aim of this study was to verify the possible correlation of the height and width of the ramus with the gender and cephalic index. MATERIALS AND METHODS: 48 adult, dentate, human mandibles were used, being dolicho- (16), meso- (16) and brachycephalic (16) specimens. The anatomic references on the ramus were: the most inferior point of the mandibular notch (I), the highest point of the inferior board (B), the most posterior point of the anterior margin, (P) the most anterior point of the posterior margin. RESULTS: The mean of the height and width of the mandibular ramus showed no difference compared with the cephalic index (dolicho – 47,05/ 32,09mm; meso – 47,27/ 32,57mm; brachicephalic – 46,41/ 29,58mm). Assessing the dimensions in light of the individuals gender showed that there was a height difference of the ramus in male individuals (49,08mm) that was higher than in female individuals (42,76mm). CONCLUSIONS: We believe our results should be used as reference in mandibular ramus surgical procedures, forensic investigations and morphometric comparisons with results of further studies in individuals from other nations.