Facial bone wound healing. An overview.

Facial bone wound healing has practical importance not only in acute fracture repair, but also in head and neck surgery. Fundamental principles of fracture fixation are now understood, and the benefit of acute bone grafting has emerged. In the future, bone healing may be augmented with growth factors and implants incorporating cells grown in tissue culture.

Calvarial bone repair with porous D,L-polylactide.

Bone is a storehouse of biologic factors enabling it to regenerate without scar formation. Recombinant technology has made many of these factors available in significant quantity for therapeutic applications. However, a system to deliver recombinant bone-regenerating factors is needed. Biodegradable, biocompatible polymers have shown promise for delivering bone regenerative factors, such as bone morphogenetic protein. The polymer we selected to investigate was racemic D,L-polylactide. Our immediate objective was to engineer porous D,L-polylactide to promote bone ingrowth (osteoconduction). We tested the hypothesis that porous D,L-polylactide implanted in a standard intraosseous calvarial wound would not hinder but would support bone regeneration. Therefore porous polylactide disks (65% void volume) were manufactured with pores < or = 100 microns, < or = 200 microns, and < or = 350 microns; implanted in rabbits' calvariae, and retrieved 1, 2, 4, and 6 months after insertion. Quantitative histomorphometry revealed a possible relationship in the amount of bone ingrowth with increasing pore size over time. The D,L-polylactide disks < or = 350 microns had the greatest quantity of bone ingrowth (< or = 0.05). However, a disturbing finding was the multinucleated giant cell response associated with all implanted disks. We speculate these cells may have produced an inhospitable environment stifling osteoconduction. Consequently, postsynthesis engineering refinements of D,L-polylactide to eliminate the giant cell response are crucial before loading with bone morphogenetic protein.

Effect of a bioresorbable film on regeneration of cranial bone.

Regeneration of cranial bone is usually accomplished with autografts, banked bone, or both. The effect also may be obtained by using a properly engineered alloplastic barrier. Our group assessed histomorphometrically the capacity of a bioresorbable film to promote repair of cranial bone in critical-sized defects in 50 rabbits divided over four time periods (4, 8, 16, and 24 weeks). A single circular defect 15 mm in diameter was prepared in each rabbit and either covered with films of polylactic acid (21 mm in diameter, 150 microns thick) durally and pericranially or left untreated. Only after 24 weeks was there a significant difference (p < or = 0.05) between defects covered with polylactic acid films and those untreated. We conclude that after shorter periods, regardless of covering, prolapse of soft tissue into defects prevented osseous regeneration. We speculate that at 24 weeks, defects treated with films generated new bone as a result of changes in the local milieu conducive to osteoblastic expression.

Present day status of the chemical face peel.

A phenol chemical face peel restores a clean, youthful appearance by removing the fine wrinkles of the tired, aged face. This procedure has the additional advantage of decreasing the rate of appearance of precancerous and probably early cancerous lesions of the photoaged skin of the face. Knowledge of the history, theory, histology, and technique are made current. A comprehensive review demonstrates that pigmentary changes, third degree scarring, and cardiac arrhythmias appear to be the main complications. The technique is safe and effective if used in a judicious manner.

Repair of complicated mandibular defects.

In most instances, the injured mandible can be successfully repaired with arch bars and intermaxillary fixation. However, it is important to identify certain potential problem situations early and apply special techniques for their treatment. Potential management problems, such as the non-compliant patient, the edentulous patient, gunshot wounds, radiated mandibles, tumors, and osteomyelitis, are reviewed. The use of special techniques, eg, the dynamic compression plate, the Morris biphase apparatus, the cobalt-chromium alloy (Vitallium) basket, a suction-irrigation apparatus, and the mandibular reconstruction plate, are described to show how they may be effectively applied to these special situations. With early recognition of these management problems and proper application of these more sophisticated techniques, the quality of care for patients, with mandibular injuries can be enhanced.