Faculty Bibliography

OBJECTIVE:The purposes of this investigation were to study the feasibility of placing endosseous implants in children and adolescents with ectodermal dysplasia and to assess the position and stability of such implants during growth. This article reports on 6 subjects with long-term follow-up. Study design. A prospective study was commenced in 1991. Patients with hereditary ectodermal dysplasia who were over the age of 5 years and who presented to the University of California San Francisco Ectodermal Dysplasia Clinic for dental treatment were included and maintained in the study. In each case, clinical and radiographic records were obtained before treatment, immediately after implant placement, at delivery of the prosthesis, and subsequently at yearly intervals. Six subjects are reported, 4 as members of the prospective study group and 2 who had been treated before the study began. RESULTS:A total of 41 implants (19 maxillary, 22 mandibular) were placed. The average follow-up after implant placement was 7.8 years (range, 6-11 years), and the average time since restoration was 6 years (range, 5-10 years). Forty implants successfully integrated and have been restored. There was no evidence that implant placement or prosthetic rehabilitation resulted in restriction of transverse or sagittal growth. One mandibular implant, placed in a partially dentate 5-year-old, became submerged because of adjacent alveolar development and required placement of a longer abutment. Four maxillary implants placed in a partially dentate 7-year-old also became submerged and required prosthetic revision and the placement of longer abutments. CONCLUSIONS:This preliminary report suggests that endosseous implants can be successfully placed and can provide support for prosthetic restoration in patients with hereditary ectodermal dysplasia. However, vertical dentoalveolar growth results in submergence of the implant relative to the adjacent natural dentition when implants are placed adjacent to erupting permanent teeth.

OBJECTIVE:The purpose of this cadaver dissection study was to investigate the anatomy of the nasolabial fold with a view to explaining the problems of surgical softening or elimination of the fold. STUDY DESIGN/METHODS:Ten formalin-fixed cadavers and 6 fresh-frozen cadavers were used for this study. In 12 cadavers (8 formalin-fixed, 4 fresh-frozen), the nasolabial fold was sectioned at right angles to the fold for histologic examination, and in 4 cadavers (2 formalin-fixed, 2 fresh-frozen) the epithelium was dissected off the fold to allow for more detailed gross examination of the underlying musculature. RESULTS:The fold was clearly identified on 14 of the cadavers but was indistinct on 2 on gross examination. Beneath the fold were 2 muscle bundles. The more superficial muscle runs parallel to the fold whereas a deeper muscle runs at right angles to it. The buccal fat pad lies above the fold and appears to be retained by horizontal septae in the fat pad and also by the musculature of the fold. Cadavers showing a poorly defined nasolabial fold had fewer muscle bundles to support the fat and fewer fibrous septae running through the fat. CONCLUSIONS:The nasolabial fold is defined by structures that support the buccal fat pad and hold it above the fold. This appears to be a combination of muscle bundles that run both across and parallel to the fold and also by fibrous septae supporting the fat pad. This has implications for the development of surgical procedures to soften or eliminate the fold, which must separate the muscles from the dermis of the fold and allow the fat to descend and soften the fold.

Thin Silastic sheet alloplasts (Dow Corning, Midland, MI, U.S.A) are commonly used to reconstruct posttraumatic orbital floor defects. Complications associated with orbital Silastic implantation include infection, migration, and extrusion. The authors report an unusual case of an intraorbital, squamous, epithelial-lined cyst appearing as progressive vertical globe dystopia and proptosis occurring after Silastic reconstruction of a traumatic orbital floor defect

OBJECTIVE: The purpose of this cadaver dissection was to study the position of the auriculotemporal nerve in relation to the mandibular condyle, capsular tissues, articular fossa, and lateral pterygoid muscle and to evaluate the anatomic possibility of nerve impingement or irritation by the surrounding structures. STUDY DESIGN: Eight cadaveric heads (16 sides) were dissected. The auriculotemporal nerve was identified by following its course around the middle meningeal artery. The course of the nerve trunk was dissected from the middle meningeal artery to the terminal branches within the temporomandibular disk. The horizontal distance between the auriculotemporal nerve and the medial portion of the condyle/condylar neck was measured. The vertical distance from the most superior portion of the articular condyle to the superior border of the auriculotemporal nerve was measured. RESULTS: The auriculotemporal nerve was identified on each side, and a single trunk was evident along the medial aspect of the condylar neck. At the posterior border of the lateral pterygoid muscle, the nerve trunk was in direct contact with the condylar neck in every specimen. The average vertical distance between the superior condyle and the nerve was 7.06 mm (+/- 3.21 mm); the range was 0 to 13 mm. The vertical distance between the nerve and the superior condyle on one side of the specimen did not correlate with the distance on the contralateral side. CONCLUSION: The auriculotemporal nerve trunk has a close anatomic relationship with the condyle and the temporomandibular joint capsular region, and there is evidence of a possible mechanism for sensory disturbances in the temporomandibular joint region. In all cases, the nerve was in direct contact with the medial aspect of the capsule or condylar neck. Because there is no correlation between the positions of the nerves on the right and left sides, only one side may be affected. The nerve was also observed to course in direct apposition to the lateral pterygoid muscle. The findings support the hypothesis that the anatomic and clinical relationship of the auriculotemporal nerve to the condyle, articular fossa, and lateral pterygoid muscle may be causally related to compression or irritation of the nerve, producing numbness or pain, or both, in the temporomandibular joint region

PURPOSE: This study is a retrospective chart review designed to evaluate the incidence and reasons for removal of plates and screws after Le Fort I osteotomy. PATIENTS AND METHODS: The study sample consisted of patients who underwent Le Fort I osteotomy at the University of California, San Francisco, and Northwestern University in Chicago between December 1985 and December 1994. All patients in the study were treated with internal fixation using 2.0-mm plates and screws. All data were obtained from medical records and operative reports. The following intraoperative variables were evaluated: hardware material, plate size and shape, plate location, screw size, graft material, and intraoperative complications. For patients requiring removal of hardware, the number, location and type of plates and screws removed were recorded, as well as the reasons for removal. RESULTS: A total of 738 plates were placed in 190 patients. Twenty-one of the 190 patients (11.1%) had at least a portion of the hardware removed because they either requested removal or required removal secondary to complications related to the plate or screw. This represented 70 of 738 plates (9.5%). The percentage of titanium plates removed was greater than the percentage of Vitallium plates removed. The reasons for removal included pain, palpation by the patient, sinusitis, temperature sensitivity, infection, and patient request. CONCLUSION: Only a small number of patients (10.6%) develop complications from plates or screws that required their removal. In each case, prompt removal constituted adequate management

SPECIFIC AIM. To evaluate the take of skin grafts on conventionally prepared beds and on beds prepared by a carbon dioxide laser, with and without abrasion of the bed. SIGNIFICANCE. Graft take is dependent on hemostasis, immobility, and nutrition of the graft. Scalpel excision of the skin graft can be associated with hemostatic difficulties and laser treatment of the skin graft bed can provide hemostasis. Abrasion of the bed after laser treatment may then be a means of opening small lymphatic and blood vessels to maintain the graft. Laser treatment followed by abrasion of the bed may provide an ideal graft base before suturing of the skin graft. MATERIAL AND METHODS. Full-thickness skin grafts were taken with a scalpel at three sites on the dorsal skin of 24 guinea pigs. The three beds were prepared with pressure alone to provide hemostasis, laser vaporization followed by abrasion with gauze to produce pinpoint bleeding, and laser vaporization alone. The original skin from each of the sites was then sutured back in place. At postoperative days 1, 3, 5, 10, 21, and 35 the graft sites were assessed clinically for 'take.' Laser Doppler measurements were also made to evaluate blood flow. Histologic sections of the three sites were prepared. Immunohistochemical analysis was performed to evaluate cell proliferation and angiogenesis. RESULTS. For the animals sacrificed through day 10 the rate of take for the sites that were not lased was 100%. For the sites that were lased alone and lased and abraded the rate of take was 71% with no difference between the two techniques. The lased sites demonstrated increased inflammatory response and graft necrosis. Immunohistochemical analysis showed increased cellular proliferation and angiogenesis in the bed. DISCUSSION. Grafts take best on a scalpel-prepared bed. Laser preparation of the bed, with or without abrasion, demonstrates decreased 'take.' Therefore the carbon dioxide laser is not a recommended means to take a graft or prepare the graft bed

Although root fractures are among the less common oral injuries (6 percent), a careful diagnostic evaluation of such injuries is required to arrive at an appropriate treatment plan. The position of the fracture in the root will determine the proper management. The problem of luxation due to trauma often involves the use of dental splints, which, if not properly designed, may cause root resorption, loss of alveolar bone, pulpal necrosis and pulp canal obliteration. The guidelines for the type of splint to use and conditions under which it should be placed are presented

PURPOSE/OBJECTIVE:This cadaver dissection studied the relationship of the buccal branch of the facial nerve to the parotid duct and its relevance to surgical procedures in this area. MATERIALS AND METHODS/METHODS:Ten cadaveric heads (twenty sides) were dissected. The superficial tissues were removed, and the buccal branch of the facial nerve and the parotid duct were identified. The vertical and horizontal relationships were recorded and analyzed. RESULTS:Eighty-five percent of the cadavers had a single buccal branch of the facial nerve, whereas 15% had two branches. In 75% of cases, the nerve was inferior to the duct as it emerged from the parotid gland, whereas in 25% of cases the nerve crossed the duct, usually from superior to inferior. CONCLUSION/CONCLUSIONS:The buccal branch of the facial nerve has a close relationship with the parotid gland for over 2.5 cm after it emerges from the parotid gland; it normally lies inferior to the duct. This relationship is of importance in performing parotid gland surgery, parotid duct surgery, and some facial cosmetic surgery.

PURPOSE/OBJECTIVE:This study evaluated the relationship of the mandibular third molar to the lingual nerve. MATERIALS AND METHODS/METHODS:An anatomic dissection of the lingual nerve in the third molar region was done on 20 cadavers (40 sides). RESULTS:The position of the nerve on one side bore no statistical relationship to the position of the nerve on the opposite side. The position of the lingual nerve was variable in both the sagittal and coronal planes. In two specimens the nerve lay superior to the lingual plate and in another the superior surface of the nerve was level with the crest of the lingual plate. CONCLUSION/CONCLUSIONS:These findings have implications for the avoidance of lingual nerve damage during surgery in the third molar and retromolar region of the mandible.