Morphometric studies on the skull of the Australian domestic cat (F. catus) and its clinical implications for regional anesthesia.

Understanding of orbital and periorbital anatomy is critical to the diagnosis and therapy of orbital disorders. Twenty-six cat heads were obtained from the dissecting room in the Discipline of Veterinary Sciences, College of Public Health and Veterinary Sciences, James Cook University, Townsville, Australia for use in this study. After macerating the heads and cleaning the skulls they were grouped by morphology into 15 round-headed and 11 flat-headed skulls. In the flat-headed group, the skulls were elongated with a prominent constriction between the cranium and facial bones and a prominent external sagittal crest, which extended from the nuchal crest. Furthermore, complete to nearly complete fusion of the zygomatic process of the frontal bone with the zygomatic arch resulted in a complete bony orbit. The skulls were radiographed, and a total of 32 parameters measured for each group: the skull, cranium, face, orbit and mandible were compared and analyzed. The sites of injecting the infra-orbital, mandibular alveolar and mental nerves were confirmed in both groups of cat skulls. We conclude that old age plays a major role in forming the skull shape (rounded versus flattened) and clo- sure of the orbital rim.