[Use of porous plyethylene (Medpor) in maxillofacial surgery].

The use of alloplastic material in maxillofacial surgery is having a much larger diffusion in substituting missing bone parts and in incrementing those that already exist. Medpor, a substance composed of porous polyethylene, has been of relatively recent introduction in the surgical field. Due to its characteristics of biological compatibility, easy morphological adapatability and mantaining it's initial volume after beeing positioned, Medpor lends itself well as an alternative to autogenous grafts or other alloplastic materials. The authors consider twenty patients operated between May 1991 and September 1993 with Medpor grafts; seven of these were affected by microgenia, and were submitted to vertical increase of the chin after horizontal osteotomy by interposing Medpor. Two patients affected by hemifacial microsomia had been treated with grafts on the mandibular border in order to improve their facial symmetry. In three cases Medpor was used in patients affected by previous traumas: to reconstruct a fractured orbital floor with bone loss, the dorsum of the nose, and in order to regain protrusion of the cheekbone. In two patients affected by UCLP Medpor was used in sustaining the lateral region of the nose as well as in disguising hypoplasia of the upper jaw. In other two cases Medpor had been used to fill a depression created in the temporal region where the muscle had been rotated to create a flap; other uses of Medpor have been: as a filler of titanium mesh, used in the reconstruction of a nasal valve and in the camouflage of the upper jaw. The authors report complications only in three cases all involved the exposure or prominence of the Medpor grafts. In one case the prominence of the grafts which was positioned on the upper jaw appeared in the upper part of the fornix; in another case the exposure was post-traumatic and in the third case the exposure followed the dehiscence of the titanium prosthesis within which the Medpor had been positioned. Except for the last case, in which the patient died--for other reasons--healing of the graft exposure was obtained by a simple remodeling.