Divided and reunited maxillary artery: developmental and clinical considerations.

We describe an anatomical variation of the right maxillary artery, discovered during dissection of a male human cadaver. The right maxillary artery bifurcates into unequal superficial (larger) and deep (smaller) divisions. Each division gives off several branches that distribute to the muscles of mastication, facial structures, and teeth. The superficial and deep divisions then reunite to form a complete loop, before giving off terminal branches in the pterygopalatine fossa. The entire arterial loop lies superficial to the branches of the mandibular nerve. This case provides further evidence for a network of vascular rings that surround soft tissue structures in the developing infratemporal fossa. Persistence of all or part of these rings determines adult anatomy. Extreme anatomical variations such as this one may complicate major procedures such as radical maxillectomy, as well as simple procedures such as inferior alveolar nerve blocks.