Extraoral cranial implant-retained prosthetic reconstructions have been proved to be highly successful. Replacement of the eyes, ears, nose, and larger areas including combined midface defects, which frequently have no other option available, has been done successfully. Burn patients and those with congenital defects are good candidates for this type of reconstruction, especially after autogenous attempts have failed. Cranial implant prosthetic reconstruction should be considered as a viable option for difficult craniofacial defects.
Reconstruction of acquired or congenitally absent facial structures such as ears, eyes, the nose, and other structures is a challenging task for the reconstructive surgeon. Often, inadequate soft tissue, cartilaginous structure, or osseous structure exists for a reconstruction that is both functional and aesthetic.
The use of external titanium cranial implants for prosthetic reconstruction in the head and neck region was developed from the pioneering work of Branemark, Briene, Adell Lindstrom, and other investigators in the late 1960s and early 1970s. Because this technology emerged as a reliable reconstruction method for the maxillofacial/oral region, early work began regarding extraoral applications of the titanium osseointegrated implant. Initially, concerns regarding long-term stability and recurrent infection were vocalized by many investigators. Subsequently, however, work in the late 1970s and early 1980s by Tjellstrom, Albrektsson, Branemark, and Lindstrom revealed that the extraoral application of titanium implants for prosthetic reconstruction, bone-anchored conductive hearing aids, and other applications was a reliable technique. Following the initial application of this technology for auricular reconstruction, other reconstructive procedures using osseointegrated retention such as orbital, nasal, and frontal prostheses have been evaluated in the literature.
Most researchers agree that prosthetic reconstruction of the ear results in a cosmetically superior result when than that of autogenous reconstruction. This disparity does not imply that traditional reconstructive techniques cannot achieve an excellent aesthetic result; however, the complex anatomy of structures such as the ears and nose can be extremely difficult to reconstruct and nearly impossible to replicate with traditional reconstructive surgery. Implant-retained prostheses offer an excellent reconstructive option that provides for excellent symmetry, color, and anatomic detail. Further, prosthetic reconstruction offers a rescue option for unacceptable or failed autogenous grafting procedures.
Implant-retained prostheses offer several advantages over more traditional prosthetic techniques. Cranial implants provide secure attachment of the prosthesis that obviates the need for adhesives, double-sided tape, glasses, or other more traditional fixation methods, which may compromise prosthetic stability. Cranial implants enhance the patient’s quality of life via improved self-image, greater activity level due to superior retention, and ease of prosthesis management. Traditional adhesives have several disadvantages such as discoloration of the prosthesis, skin reactions (especially in irradiated areas), and poor performance during activity or perspiration. Another significant advantage of cranial implantation is that the technique avoids distortion of tissues inherent in traditional surgical reconstruction, which allows for superior tumor surveillance. It has been suggested, despite difficulties with osseointegration in irradiated bone, that cranial implants may have an advantage in the irradiated patient who has poor-quality soft tissues available for reconstruction.
Several disadvantages to prosthetic reconstruction exist, including the necessity of prosthetic or implant maintenance because of normal wear and discoloration and depending on the level of the patient’s activity. The prosthesis may be dislodged at inopportune times such as during social or athletic events, and some investigators have noted that some patients may have adverse psychological effects related to the prosthesis.