There are numerous small bumps on the skull that can occur that can be aesthetically bothersome. Some common examples are osteomas of the forehead and occipital knobs on the back of the head. Many of these skull bumps are pathologic, meaning their presence is abnormal even if they only cause an aesthetic issue.
There are some skull bumps, however, that are perfectly normal and represent no pathology at all. The mastoid bump or process is one of these normal bumps that patients occasionally would like reduced. In my experience these are all men who either shave their heads or have very short hair cuts. Unlike other skull bumps the mastoid process is unique.
The mastoid process is a smooth round projection of bone located behind the ear at the lower end of the temporal bone. Certain scalp muscles (occipitofrontalis) and neck muscles (e.g., sternocleidomastoid) attach to it. What makes it unique is that it is a sinus cavity filled with air cells. Thus, somewhat similar to the frontal sinus, there is a limited amount of outer cortical bone that can be removed before the air cells become exposed.
To reduce the visible mastoid prominence a postauricular incision is used. This can be put directly in the crease or just beyond it. Either way the incision placement makes it invisible. By elevating the scalp and releasing the soft tissue attachments the mastoid prominence can be seen and reduced using a high speed burring technique.
Because of the underlying air cells the outer cortical bone layer can be reduced 2 to 3mms, sometimes 4mms. The bone should be taken down slowly as it won’t be long until a bluish hue is seen which means one is looking through the thin bone at the air cells. At this point the reduction is complete. Closure is done with three layers of resorbable sutures. A drain is is used if temporal reduction is also done, which is often combined with mastoid prominence reduction. If done alone then no drain is needed.
Dr. Barry Eppley
World-Renowned Plastic Surgeon