Overview
The dog skull is divided into the braincase (neurocranium), protecting the brain, and the facial skeleton (viscerocranium), forming the nose, the orbits and the mouth. Its shape varies enormously between breeds: dolichocephalic (Greyhound, Collie), mesocephalic (Labrador, German Shepherd) and brachycephalic (Bulldog, Pug), which affects eye position, dentition and the airway. This model is a mesocephalic skull.
Key features
- Occipital bone: forms the base and caudal part of the skull, with the foramen magnum and the occipital condyles that articulate with the atlas. The external occipital protuberance is palpable on the midline.
- Sagittal crest and zygomatic arches: origin and insertion of the powerful masticatory muscles (temporalis and masseter).
- Frontal bones: contain the frontal sinuses and form the dorsal rim of the orbit, which in the dog is incomplete caudally (closed by the orbital ligament).
- Maxilla and incisive bone: hold the upper teeth; the maxilla contains the maxillary recess and the infraorbital foramen, a site for nerve blocks.
- Nasal bones and conchae: form the nasal cavity, highly developed in the dog.
- Tympanic bulla: ventral bony cavity housing the middle ear.
- Temporomandibular joint: mandibular fossa of the temporal bone, bounded caudally by the retroarticular process.
Clinical relevance
Head trauma, zygomatic arch and maxillary fractures, otitis media (tympanic bulla, bulla osteotomy), nasal neoplasia and brachycephalic syndrome are the most frequent conditions. The infraorbital and maxillary foramina are used for dental nerve blocks.