The bicoronal flap (craniofacial access): an audit of morbidity and a proposed surgical modification in male pattern baldness

Maxillofacial surgeons have used the bicoronal flap for nearly three decades to gain access to the craniofacial skeleton. A retrospective analysis of 68 bicoronal flaps done over a five-year period showed that our incidence of permanent morbidity was low. Although 24 patients (35%) experienced some form of sensory abnormality immediately after the operation, this persisted for longer than two years in only one. Complete motor recovery occurred by one year in all 15 patients (22%) who developed postoperative frontalis weakness. Three patients developed male pattern baldness postoperatively, which resulted in exposure of the scar and poor cosmesis. This prompted a cadaveric study in which we assessed the feasibility of modifying the position of the standard bicoronal incision in people who are prone to hair loss. The pivotal point of the bicoronal flap was found to lie at its most inferior aspect. By extending the incision into the skin crease in front of the lobe of the ear it was possible to adjust the anteroposterior position of the bicoronal incision without limiting access to the facial skeleton. We therefore advocate occipitally placed incisions with preauricular extensions in patients who are prone to male pattern baldness.