The occipitotemporal or occipitomastoid suture is the obliquely oriented articulation of the anterior border of the squamous occipital bone and the mastoid portion of the temporal bone. A mastoid foramen is occasionally located near or in it.
The occipitotemporal suture and the parietotemporal suture meet the lateral end of the lambdoid suture at the asterion, which is the site of the posterolateral fontanel in the fetal/neonatal skull, which closes during the second year of life. The occipitotemporal suture itself typically fuses at approximately age 16.
A small triangular area termed the jugular growth plate, located posterolateral to the jugular foramen in the occipitotemporal suture, is the last part of the skull to show active age-related growth.