Mandibular replacements: a review of the literature

Reliable, minimally invasive oromandibular reconstruction using metal plate rolled with pectoralis major myocutaneous flap

The purpose of this study was to minimize the surgical invasiveness to the donor site and the amount of the primary reconstruction time after oromandibular tumor resection. Oromandibular reconstruction was performed only using a pectoralis major myocutaneous flap and a metal plate. The pectoralis major myocutaneous flap was grafted to the oral cavity defect by rolling and wrapping around the metal plate with the muscle of the flap. No early postoperative complications have been noted in all seven patients. An average of 2 years and 1 month has past since surgery, and to date no infections, plate exposure, or plate breakage have been observed in any of the patients. The safety of the oromandibular reconstruction using a metal plate was improved by rolling the muscle of the pectoralis major myocutaneous flap around the metal plate. The present method was shown to be a rational technique that allowed primary reconstruction of the oral cavity and mandible in a minimally invasive manner in a short time.

Mandibular reconstruction using a titanium plate: the impact of radiation therapy on plate preservation

PURPOSE

To evaluate the soft tissue and bone tolerance of radiation therapy (RT) in patients undergoing radical composite resection and mandibular reconstruction using a bridging titanium plate with myocutaneous flap closure.

METHODS AND MATERIALS

From 1990 to 1994, 47 patients with primary or recurrent oral cavity or oropharyngeal carcinomas were treated with radical composite resection and mandibular reconstruction using a bridging titanium plate with myocutaneous flap closure. Eleven patients received no RT (no RT), 10 patients received RT greater than 10 months from the time of surgery (remote RT), and 26 patients received RT within 12 weeks of surgery (perioperative RT). The radiation dose to the reconstructed mandible ranged from 45 to 75 Gy (median 63 Gy). The effect of the titanium plate on the radiation dose was measured using film dosimetry and soft tissue and bone-equivalent materials. The median follow-up was 17 months (range: 3-50 months).

RESULTS

Late complications included four patients with osteomyelitis or necrosis, two plate exposures requiring flap revision, one chronic infection, two cases of chronic pain, two fistulae, and one case of trismus and malocclusion. The crude incidence of late complications by treatment was: (a) no RT: 3 of 11 patients (27%); (b) remote RT: 2 of 10 patients (20%); and (c) perioperative RT: 9 of 26 patients (35%). One patient in the no-RT group lost the plate due to chronic pain. Five patients in the perioperative RT group also had plate loss, four due to osteomyelitis and/or necrosis, and one due to pain related to a recurrent tumor. No patients in the remote RT group had plate loss. The actuarial prosthesis preservation rate at 2 years was 88% for the no RT, 100% for the remote RT, and 57% for the perioperative RT groups (p = 0.05). Phantom dose measurements showed that for parallel opposed 6 MV photon beams, there was no significant increase in the dose proximal or distal to the plate in either a soft tissue- or bone-equivalent phantom.

CONCLUSIONS

The impact of radiation therapy on plate preservation after mandibular reconstructive surgery using a titanium plate may be dependent on the timing of RT relative to surgery. Significantly more mandibular reconstruction plates were lost when the involved mandible received RT in the perioperative period than when RT was delivered beyond 10 months from surgery or when no RT was given. The use of alloplastic implants such as titanium plates in conjunction with myocutaneous flap coverage for mandibular reconstruction is attractive because it allows immediate reconstruction of the defect and promotes a good functional and cosmetic result; however, administration of perioperative RT may result in a higher plate failure rate.

Application of compact aluminum oxide ceramic implants in maxillofacial surgery

In a 4-year period, 40 compact aluminum oxide ceramic implants fixed with titanium plates and screws were used: 24 for the correction of mandibular defects, 9 for temporomandibular joint replacement, and 7 for augmentation of facial contour. During the 1 to 4 years following the operations, it was not necessary to remove any aluminum oxide joint or implant used for contour correction. In 5 of the 24 cases of mandibular reconstruction, however, it was necessary to remove the ceramic. In 3 cases, this was due to recurrence of the tumor, and in 2 cases the cause was dermal necrosis.

The difficulties of prosthetic management of edentulous cases with hemi-mandibulectomy following cancer treatment

The presenting features of edentulous subjects who have undergone hemimandibulectomy for the removal of squamous cell carcinoma of the mouth are described. Suggested methods of prosthetic treatment are discussed and the means of assessing problems of speech and swallowing with sequential radiography are reported.

Photoelastic stress analysis of hemimandibulectomy bone reconstruction devices

The results presented show the relative importance of muscle force and occlusal resistance locations and prosthesis/hemimandible interface length. For the prosthesis design used, the addition of muscle function on the prosthesis side has little effect upon bone stress. However, occlusal resistance on the prosthesis side produces much more stress in the bone than other resistance positions. Stress produced by the shorter prosthesis is higher at the areas of bolt/bone interface than for the long prosthesis. However, superimposed inherent stress patterns somewhat obscured the comparison with longer prostheses.