The connection between the bones of the skull may be loosened, and their sutures separated (diastasis). This separation very rarely occurs, and is less important as a result of violent injury to the skull from falls, blows, etc, than when it takes place in consequence of a rapid advance and extreme degree of hypertrophy of the brain, or of hydrocephalus.

The opposite anomaly is that of a premature closure of some, or all, of the sutures. From the thinness of the cartilage the sutures generally unite first at the inner surface of the skull.

Of the bones of the face, the lower jaw may be dislocated, or its joint anchylosed.