Custom skull implants are most commonly performed for flat areas of the back of the head. For flat spots in the back of the head the most common etiology is plagiocephaly, a unilateral or one-sided flat area on the back of the head. While plagiocephaly causes deformations of the entire shape of the skull (cranioscoliosis) the flat area on the back of the head is usually of greatest concern to most patients. (as opposed to the forehead protrusion or the more anterior position of the ear on the flat side)
In designing and placing skull implants for plagiocephaly it becomes apparent that the flat area on the back of the head involves more than just the back of the head. On the affected side it extends around onto the side of the head onto the posterior temporal area which is covered by muscle.The flat area of the bone and the subsequent implant design crosses over the bony temporal line onto what is a muscular area. The bony temporal represents the broad origin of the temporal muscle.
As a result the dissection for the implant placement as well as the implant itself occurs on top of the deep fascia of the muscle. On the opposite side the implant design either does not cross the bony temporal line or crosses over only slighty onto it. This difference between how far the dissection proceeds onto the side of the head affects the immediate after effects of the surgery.
As a result on the flatter side there is going to be considerable more swelling that extends onto the anterior temporal region as well as the eye area. There may even be some bruising as well that works its way into the eyelids. This is perfectly normal and expected given the difference in the dissection between the two sides of the posterior temporal region.
Dr. Barry Eppley
World-Renowned Plastic Surgeon