Four-headed biceps and triceps brachii muscles, with neurovascular variation.

Anatomical variations of the biceps brachii and triceps brachii have been described by various authors, but the occurrence of four-headed biceps brachii and triceps brachii in an ipsilateral arm is rare and has not been reported before in the literature. During routine cadaveric dissection in the department of anatomy, Kasturba Medical College, Mangalore, India, various unusual variants were noted in the left arm of a cadaver of a 67-year-old man. The variants include a four-headed biceps, a four-headed triceps, communication between the musculocutaneous and median nerves, and a high origin of deep brachial artery from the axillary artery. The occurrence of these anomalies and the clinical and morphological significance are discussed.

Intraosseous course of the inferior alveolar (dental) nerve and its relative position in the mandible.

The present study was planned to evaluate the position of the mandibular foramen (MF) and the course of the inferior alveolar nerve in 12 right and 14 left cadaveric hemimandibles. The soft tissue including the muscle attachments of the mandible was cleaned and the inferior neurovascular bundle was dissected up to the MF. The distances from the MF to the angle, symphysis menti, 3rd molar, and the lower point of the mandibular notch were measured. The bone was chiseled from its lingual surface to expose the mandibular canal. The distances from the nerve to the alveolar and inferior borders were measured. The distance from the MF to different landmarks did not show any side differences except the one to the symphysis menti (P<0.05; Mann-Whitney 'U' test). Similarly the distances from the nerve to the borders also did not show any significant side differences. These data indicate that, on average, MF is located at a symmetrical point on the ramus on either side, although, not exactly at a fixed distance from any landmarks tested. Further, the canals were located either at near to the middle or below near to the base of the mandible. This study concludes that, the location of the MF varies from bone to bone despite its bilateral symmetry. Further, the canal and consequently the nerve do not maintain a constant position in the mandible.