The effects of zygomatic complex fracture on masseteric muscle force.

The masseter muscle often has been implicated as a primary cause of postreduction displacement of the fractured zygomatic complex. However, this contention has never been proved. This study compared masseter muscle force in 10 male controls with that in 10 male patients who had sustained unilateral zygomaticomaxillary complex (ZMC) fractures. Calculation of muscle force was based on measured bite force, electromyogram, and radiographic determination of muscle vectors. It was found that the masseter muscle in patients with ZMC fractures developed significantly less force than masseter muscle in controls. Following fracture, the masseter force slowly increased, but at 4 weeks following surgery the majority of patients were still well below control levels. The results of this study cast uncertainty on the role of the masseter muscle in postreduction displacement of the fractured ZMC.     

Use of a 2.0-mm locking plate/screw system for mandibular fracture surgery.

PURPOSE: In this study, we examined the use of a 2.0-mm locking bone plate/screw system in mandibular surgery. PATIENTS AND METHODS: All patients who were treated with a 2.0-mm locking bone plate/screw system during an 8-month period for fractures of the mandible or other defects of the mandible were prospectively studied. Ease of use of locking plate/screw system, characteristics of the fractures and defects, and complications were tabulated. RESULTS: A total of 80 fractures in 59 patients were treated with the 2.0-mm locking plate/screw system. One hundred two 2.0-mm locking plates were applied to the 80 fractures; 58 fractures received 1 plate and 22 fractures received 2 plates. There were no intraoperative difficulties associated with their application. Fracture reductions were considered to be excellent in all cases. At the latest follow-up, all fractures had healed, but 2 patients had slight malocclusions. Six patients developed postsurgical infections. Only 1 patient required hospitalization for treatment of the infection; all others were managed in the outpatient clinic. Four patients required removal of their plates for varying reasons. CONCLUSIONS: The use of a 2.0-mm locking plate/screw system was found to be simple and to provide sound fixation in all cases.     

Solitary plasmacytoma of bone: clinical features, treatment and survival.

Eleven patients with solitary plasmacytoma of bone were seen between 1978 and 1991. A retrospective review of the clinical features, treatment and survival of these patients was made with the aim of helping to define those at risk for early development of myeloma. Nine patients (82 per cent) had paraparoteinemia at diagnosis. Treatment consisted of local irradiation plus or minus surgery (nine patients) and surgery alone (two patients). No patient received adjuvant chemotherapy. One patient had evidence of both generalized osteopenia and immunoparesis, and progressed to myeloma within six months. Four patients (36 per cent) progressed to myeloma. All of these had paraprotein levels which continued to rise following initial treatment. Three patients died of myeloma at 12, 81 and 144 months and the other patient is alive with myeloma at 76 months. Patients without paraproteinemia at presentation or whose paraprotein decreased after treatment did not progress to myeloma. Three patients have been followed for 8, 11 and 19 years with no evidence of myeloma. Failure of paraprotein to clear after local treatment suggests occult disseminated disease and is predictive of later development of overt myeloma.     

The value of a diagnostic setup for full fixed maxillary implant prosthetics.

The concept of prosthesis-directed implant-supported restoration is well accepted. The implementation of this principle for patients requesting full fixed implant-supported maxillary prosthetics has not been thoroughly described. We present a technique for the evaluation and preprosthetic surgical management of patients who are edentulous in the maxilla and wish to have fixed implant-supported crown and bridge prosthetics.