During this study, fifteen shark heads of sand tiger shark Carcharias taurus (Rafinesque, 1810) were analyzed. The studied material was obtained in the Santos Fishing Terminal, São Paulo, Brazil. The heads dissection was focused on the characterization of the mandibular muscles and on the description of the mandibular branch of the trigeminal nerve. The C. taurus mandibular muscles are represented by: m. preorbitalis, m. levator palatoquadrati, m. quadratomandibularis and m. intermandibularis. The origin of the trigeminal nerve of C. taurus is located in a lateral portion of the medulla oblongata. In the orbita, the trigeminal nerve branches off to originate the mandibular branch that innervates the muscles which are derived from the mandibular arch. The proximal branches of the trigeminal nerve mandibular branch innervate the m. levator palatoquadrati. The muscles preorbitalis and quadratomandibularis receive fibers from the intermediate branches of the trigeminal nerve mandibular branch and the distal ramification of the mandibular branch can be visualized in the m. intermandibularis

Fueron analizadas 15 cabezas de tiburón toro Carcharias taurus (Rafinesque, 1810), obtenidas en el Terminal Pesquero de Santos, São Paulo, Brasil. La disección permitió caracterizar los músculos mandibulares y describir la rama mandibular del nervio trigémino. Los músculos mandibulares de C. taurus son: M. preorbitalis, M. levator palatoquadrati, M. quadratomandibularis y M. intermandibularis. El origen aparente del nervio trigémino de C. taurus está localizado en la porción lateral de la médula oblonga. En la órbita, las ramas del nervio trigémino salen para dar origen a la ramificación mandibular, la cual inerva a los músculos derivados del arco mandibular. Las ramificaciones proximales de la rama mandibular del nervio trigémino inervan al M. levator palatoquadrati. Los Mm. preorbitalis y quadratomandibularis reciben fibras de las ramas intermedias de la ramificación mandibular del nervio trigémino, y el M. intermandibularis recibe la ramificación distal de la rama mandibular del nervio trigémino

O presente trabalho analisa a ocorrência de desvio radicular em 115 incisivos centrais e intermédios, 34 caninos e 19 quarto pré-molares superiores, totalizando 168 dentes. O desvio foi avaliado por imagens de vídeo VHS sobrepostas a um quadriculado. Os resultados mostram que 77,4% dos incisivos apresentam desvios, sendo 61,0% moderados, 28,5% pequenos e 10,5% severos (estes, apenas nas extremidades do terço apical), de acordo com adaptação da técnica proposta por SCHNEIDER6 para determinação e classificação do grau de curvatura dos canais. Para os caninos anotam-se 47,1% dos dentes com desvio, sendo 75,0% moderados e 25,0% pequenos. E para os quarto pré-molares superiores observam-se 89,4% dos dentes com desvio, sendo 75,0% moderados, 16,7% pequenos e 8,3% severos. Comparados aos desvios radiculares observados na Odontologia Humana, concluímos que a ocorrência dos mesmos é baixa para a espécie canina facilitando a instrumentação do canal radicular.

This paper studied the deviation of the root in 115 central or intermediate incisors teeth, 34 canine teeth and 19 upper fourth pre-molar teeth, totaling 168 teeth. The deviation was evaluated by means of images taken in VHS Systems of all teeth projected in a square-lined transparent sheet. The results showed 77,4% of deviation for the incisors, with 61,0% being moderate, 28,5% slight and 10,5% severe (the latter, only in the apical third of the root), according to SCHNEIDER’S6 classification of curvature of the root canals. For the canine teeth, 47,1% showed deviation, with 75,0% moderate and 25,0% slight. For the upper fourth pre-molar the there were 89,4% deviated roots, with 75,0 % moderate deviation, 16,7% slight and 8,3% severe ones. As compared to teeth of human beings, the deviation of the root in teeth of dogs is low, showing much less pitfalls for the root canal treatment, mainly its instrumentation.