Barry L. Eppley

Enhancement of angiogenesis by bFGF in mandibular bone graft healing in the rabbit

The effectiveness of basic fibroblast growth factor (bFGF) as an in vivo angiogenic factor was evaluated in autogeneic bone grafts to the rabbit mandible. Block cortical grafts harvested from the ilium were implanted into sites in the mandibular ramus or body. The basic fibroblast growth factor was continuously introduced over a period of 14 days through subcutaneous osmotic pumps. Increased vascularity, as assessed by vessel number and depth of penetration into the grafts, was noted at 10 days postoperatively in the bFGF stimulated side as compared to contralateral control grafts. At the fourteenth postoperative day, bFGF administration was discontinued and a decrease in angiogenesis was noted over the ensuing 2 weeks so that after 1 postoperative month, little difference could be detected between the stimulated and nonstimulated grafts. Assessment of osseous healing at the 1 month postoperative interval using triple fluorochrome labeling did not reveal evidence of accelerated osteogenesis on the previously stimulated side.

Collagen tube repair of the mandibular nerve: A preliminary investigation in the rat

A technique for repair of the inferior alveolar nerve of the rat involving a collagen tube conduit with laminin gel lining was compared with unguided regeneration in both large and small nerve gaps. No significant morphologic differences were noted between the groups with small defects. With large defects, however, only the tubular repairs were effective in restoring neural continuity. The implications of the results of this study are discussed.

Facial nerve graft repair: suture versus laser-assisted anastomosis

An experimental study was conducted to evaluate the effectiveness of laser-assisted versus conventional suture repair of facial nerve grafts in the rabbit. Electrophysiologic assessment of function revealed no significant difference between the two techniques. Histological differences were apparent, however, early postoperatively from the effects of heat energy on the perimeter of fascicular morphology. At a later stage, this effect had disappeared. The laser technique was also associated with an apparent decreased escape and entrapment of axons.

Secondary management of the premaxilla in bilateral cleft lip and palate patients

Bilateral clefts of the palate pose difficult and unique problems in surgical rehabilitation. The premaxilla traditionally has been a controversial subject with a historic lack of uniformity in treatment protocol. Based on a review of facial growth and the evolution of premaxillary cleft surgery, principles of management and secondary reconstruction of the premaxilla are discussed. Timely surgical intervention combining osteotomies and bone grafting in conjunction with closure of soft tissue defects is shown to result in satisfactory functional and aesthetic results.

An animal model for advanced microsurgical training

A model for advanced microsurgical training that uses the cervical neurovascular structures of the rat is presented. Various uses and technical considerations are discussed.

Surgical treatment of internal derangements of the temporomandibular joint: Evaluation of two techniques

One hundred ten cases of internal derangement of the temporomandibular joint were treated by high condylectomy (47) and eminectomy (63) in combination with discorrhaphy and disc repair. Preoperative and postoperative findings (greater than 24 months follow-up) relating to mandibular mobility, pain, and stability of occlusion were compared. Both procedures resulted in a reduction in symptoms, but differences in postoperative findings were observed. Each procedure resulted in increased translation, with eminectomy patients exhibiting greater opening distances at endstage evaluation. In addition, a greater incidence of residual deviation to the affected side occurred in the majority of high condylectomy patients. Although pain was reduced in both groups, less residual pain was observed in the eminectomy group. Alteration in maxillomandibular centric relation was a rare finding, seen only in two high condylectomy patients. Possible factors contributing to these differences are discussed.

Effect of different surgical repair modalities on regeneration of the rabbit mandibular nerve

A study was designed to evaluate the ability of the rabbit mandibular nerve to regenerate when exposed to crush and resection injuries, as well as to determine how differently sized resection injuries healed when repaired with either autogenous grafts or laminin-lined collagen tubulization. The nerve demonstrated a regenerative capacity over a 1-cm defect, with morphology and function that approximated normals, but could not span a 2-cm gap defect unaided. Crush injuries produced findings that were inferior to both those in normal nerves and in those with resections. In 1-cm defects, both grafting and tubular repairs produced similar results, with substantial recovery of neural function after 16 weeks. In 2-cm defects, autogenous grafting was superior to tubulization by both morphologic and functional assessment. Replacement of the lateral cortex of the mandible after nerve repair was shown to be unnecessary. The implications of these findings as they relate to nerve injury and repair in humans is discussed.

Surgical repair of defects in the rabbit temporomandibular joint disc: A comparison of various techniques

A study was designed to evaluate the effects of different types of repair (suture vs. graft), donor graft tissues (dermis vs. fascia), and methods of graft fixation (sutured vs. laser-assisted) on excisional defects of the rabbit TMJ disc made anterior to the retrodiscal tissue. Groups created to compare the different variables were assessed at 30 and 90 days postoperatively by macroscopic and histologic methods, microangiography, and mechanical strength testing. Without repair, all excisional defects of the disc failed to heal. Suturing of the reapproximated margins did not appear to promote healing or provide much strength beyond the properties of the suture material. Dermal grafts, fixed by suturing, induced healing by becoming incorporated into the disc, restoring discal continuity, and approximating normal disc strength. The use of laser-assisted tissue welding for dermal graft fixation was found to be inadequate and was subsequently abandoned. Fascial grafts could be fixed into position by both suture and laser-assistance, but consistently failed to exhibit successful transplantation and promote healing at the disc site.

Bilateral nasopalatine ducts of the premaxilla

An unusual case involving the development of patency of the nasopalatine ducts after orthopedic expansion of the premaxilla in a young child is described. The embryogenesis, clinical presentation and surgical repair is discussed.