According to current research, in approximately 2.5% of the general population the bones of the head develop to only 60–70% of their normal thickness in the months following birth. This genetic predisposition may explain why the section of temporal bone separating the<unk>  semicircular<unk>  from the cranial cavity, normally 0.8 mm thick, shows a thickness of only 0.5 mm, making it more fragile and susceptible to damage through physical head trauma or from slow erosion. An explanation for this erosion of the bone has not yet been found.
Superior canal dehiscence syndrome
Eustachian tube dysfunction
Genitopatellar syndrome
Rectovestibular fistula
Jugular foramen syndrome
Pilonidal disease
Tenonitis
Haemolacria