Team approach for closure of oroantral and oronasal fistulae.

Oroantral and oronasal fistulas present with a broad range of causation, size, duration, and extent of infection involving the nose and paranasal sinuses. Accurate diagnosis of the extent of the disease with appropriate radiographic evaluation will guide the surgeon to select an approach that addresses all of the infected sites. When significant sinus disease is found, an endoscopic approach to restoring drainage in all of the involved sinuses can promote predictably successful closure of oroantral and oronasal fistulas. The multispecialty team approach to this disease, with the concomitant management of the sinusitis and fistula closure, is a significant advance in the successful management of this chronic condition.

The incidence of altered sensation of the mental nerve after mandibular implant placement.

PURPOSE: This study was designed to determine the incidence of altered sensation in patients undergoing mandibular endosseous implant placement. PATIENTS AND METHODS: Ninety-four consecutive patients who underwent the placement of mandibular implants constituted the study group. The only patients that were excluded from this study were those who had preexisting injury to the trigeminal nerve. Patients were followed using standard neurologic testing during the period immediately following implant placement through 6 months. Four hundred five implants were placed in 43 female and 51 male patients. Implant length selection was based on panoramic radiographs using known markers to correct for distortion. In 13 of the patients, the mandibular canal was not adequately visualized, and a computed tomography (CT) scan was used to plan the implant locations. Implants were selected to be located 2 mm above the inferior alveolar canal based on the panoramic images and 1 mm above the canal based on CT images. RESULTS: Eight patients reported altered nerve sensation at their first postimplant visit (8.5%). None of the patients experienced hyperesthesia or dysesthesia. Four of the eight patients with altered sensation had no objective findings or decreased nerve function. One of the patients remained totally anesthetic for 2 months, but reported return to normal function at 4 months. CONCLUSIONS: These findings indicate that a small percentage of patients experience altered sensation after the placement of mandibular endosseous implants. Unlike previous studies, no permanent altered sensation was found. By using proper treatment planning, one can offer endosseous implants with minimal risk of injury to the trigeminal nerve.

Effect of supplemental gases on end-tidal CO2 and oxygen saturation in patients undergoing fentanyl and midazolam outpatient sedation.

Forty-six American Society of Anesthesiologists Class I and II adults were randomly assigned to one to two study groups. Each subject received 0.7 microgram/kg of fentanyl and a titrated dose of midazolam. One group received 100% supplemental oxygen (O2) while another group received 50% nitrous oxide (N2O) and 50% O2. End-tidal carbon dioxide (EtCO2) and O2 saturation (SpO2) were measured at 5-min intervals throughout the procedure. We conclude that there was no significant difference in EtCO2 or O2 saturation between the two groups.

Comparison of recovery of propofol and methohexital sedation using an infusion pump.

Two sedative anesthetic agents administered by an infusion pump were compared during third molar surgery. Forty American Society of Anesthesiologists (ASA) class I or II volunteers were randomly allocated to two groups. All subjects received supplemental oxygen via a nasal hood, fentanyl (0.0007 mg/kg intravenous [i.v.] bolus), and midazolam (1 mg/2 min) titrated to effect. Patients then received either 0.3 mg/kg of methohexital or 0.5 mg/kg of propofol via an infusion pump. Upon completion of the bolus, a continuous infusion of 0.05 mg/kg/min methohexital or 0.066 mg/kg/min propofol was administered throughout the procedure. Hemo-dynamic and respiratory parameters and psychomotor performance were compared for the two groups and no significant differences were found. The continuous infusion method maintained a steady level of sedation. Patients receiving propofol had a smoother sedation as judged by the surgeon and anesthetist.

Bone formation and implant degradation of coralline porous ceramics placed in bone and ectopic sites.

PURPOSE: This study was undertaken to determine the resorption rate of porous ceramic implants. The hypothesis was that implants placed in soft tissues would degrade more rapidly than implants placed in bone. MATERIALS AND METHODS: To test this hypothesis, implants were manufactured by applying a thin coating of hydroxylapatite onto an interconnected, porous calcium carbonate substrate. Control implants were made entirely of hydroxylapatite with identical microstructure. Two adult dogs received a total of 56 implants placed in the femur, skeletal muscle, and subcutaneous tissues. After killing the animals at 4 months, the specimens were removed, embedded in plastic, sectioned, and either stained for light microscopic examination or subjected to quantitative image analysis using a scanning electron microscope. RESULTS: Contrary to the hypothesis, the rate of degradation was faster for implants placed in bone than in soft tissue. Within the 4 months, degradation was 24% to 63% in bone, depending on the composition. However, it was not statistically significant in either intramuscular or subcutaneous tissue. A surprising observation was that bone ingrowth occurred in 67% of the implants placed in soft tissues. On average, it was 4.3% in intramuscular sites and 6.6% in subcutaneous sites. This bone was histologically normal in 71% of the implants containing bone. CONCLUSION: This study demonstrates that porous ceramic implants composed of hydroxylapatite on calcium carbonate will degrade more rapidly in bone defects than in soft tissue sites. In addition, implants with interconnected porosity and surfaces of hydroxylapatite will become ingrown with bone even after placement in soft tissues. The exact mechanisms for both of these phenomena are not understood.

Comparison of propofol and methohexital for deep sedation.

The purpose of this investigation was to compare two sedation techniques for use in outpatient third molar surgery. Forty ASA class I or II volunteers were randomly allocated to two groups. All subjects received supplemental oxygen via a nasal hood, sublimaze (.0007 mg/kg [corrected] intravenous bolus), and midazolam (.5 mg/min) titrated to effect. Using an incremental bolus technique, group A then received methohexital, while group B received propofol. Both groups maintained stable mean arterial pressure, oxygen saturation, and end-tidal CO2 throughout the perioperative period. However, group A had a dramatic increase in heart rate (26.7% versus 13.9% for group B [P < .05]). Better postoperative psychomotor performance (P < .05) as measured by the Trieger Dot analysis was demonstrated by patients who received propofol. It was concluded that propofol is superior to methohexital for intravenous sedation.

Endosteal implants following tumor surgery and avulsive trauma.

Endosteal implants are part of the reconstructive armamentarium used by head and neck surgical teams in cases of trauma or tumor ablation when inadequate residual anatomy prevents the fabrication of a traditional prosthesis. Three cases of implant supported prosthesis have been presented. Use of endosteal implants is an additional step toward functional reconstruction.

A comparison of dentoalveolar and venous blood.

Dentoalveolar blood from extraction sites immediately after surgery and venous blood from 28 adult patients was compared for quantitative, qualitative, chemical, and cellular differences. The absence of stem cells, osteoblasts, and osteoclasts from dentoalveolar blood suggests a very low osteogenic potential, no more than that of venous blood. This finding contradicts information supplied by the manufacturer of a microporous, polymeric, composite graft material recommended for use with placement of implants in immediate extraction sites and as onlay grafts to treat ailing implants. The manufacturer's directions call for mixing the alloplast with bleeding marrow harvested from holes drilled in the mandibular symphysis or from a curetted dental socket immediately after a dental extraction in order to stimulate immature marrow cells to form osteoblasts.

The role of a hospital-based dental implant center.

The role of a hospital-based implant center with dental and medical specialists working as a team is discussed. Advantages to the team include the availability of sophisticated hospital equipment and facilities. Referring dentists are encouraged to participate in and/or observe treatment performed at the implant center. Four cases treated by an implant team within a hospital environment are presented.

Preoperative laboratory assessment of hemostasis for orthognathic surgery.

Platelet count, prothrombin time, and activated partial thromboplastin time provide a baseline to evaluate patients with known coagulopathy, as well as present an opportunity to diagnose disease in previously symptom free patients. Current hematologic management of patients with Von Willebrand's disease uses heated Factor VIII that allows patients to undergo orthognathic surgery without significant risk of disease transmission from banked blood products.

Simultaneous maxillary and mandibular orthognathic surgery stabilized by rigid internal fixation.

Rigid internal fixation was used successfully in 111 consecutive cases in which both the maxilla and the mandible were mobilized simultaneously. The use of rigid fixation allowed for early mobilization of the mandible, which facilitated resumption of orthodontic therapy after surgery. The favorable short-term results achieved indicate the need to study the long-term stability of the technique.

Passive rigid fixation of sagittal split osteotomy.

To provide increased stability and to decrease intermaxillary fixation time after sagittal split osteotomy, we have used passive rigid fixation. Our method has not only achieved a diminution of intermaxillary fixation time, but it has also resulted in excellent stability and retention. A total of 72 sagittal split osteotomies were performed on 36 patients from July 1985 through December 1986. Rigid fixation was accomplished with two superior border 2.7 mm bicortical screws.

Indications for use of porous hydroxyapatite at time of endosteal implant placement.

Placement of coralline porous hydroxyapatite (PHA) at the time of first stage endosteal implant surgery has been shown to be effective in preventing mucosal dehiscence when the buccal cortex is perforated during implant placement. PHA was used to obliterate the space around the occlusal end of endosteal implants placed during tooth extraction. When vital structures would be jeopardized by full implant insertion, PHA can be placed in the area around the protruding implant to prevent mucoperiosteal flap fenestration.

A comparison of transcutaneous PO2 in patients sedated with diazepam-fentanyl or midazolam-fentanyl.

Fifty oral and maxillofacial surgery patients undergoing outpatient surgical removal of third molars under intravenous conscious sedation comprised the study group. All patients received 1 microgram/kg of fentanyl prior to receiving either diazepam or midazolam. The results show no statistically significant differences in blood pressure or pulse over time between the two groups, nor was there a statistically significant difference between the transcutaneous PO2 responses of the groups. However, a statistically significant time effect as well as a group by time interaction was present. Both groups show respiratory depression at the 8- and 10-minute time intervals. The use of supplemental oxygen and monitoring of respiration is recommended with the use of these drug combinations.