Nonunion of the mandible: an analysis of contributing factors.

PURPOSE

The aim of this study was to review our experience of nonunion of mandible fractures and to compare this information with the past and present literature. The analysis also evaluated risk factors and those conditions that lead to nonunion so that the complication may be better managed and possible avoided.

PATIENTS AND METHODS

A retrospective review of mandible fractures in a major medical center was carried out on patients treated from 1994 through 1998. The nonunion cases were evaluated for factors such as age, sex, race, cause of fracture, location of fracture, delay until the patient obtained treatment, teeth in the fracture line, use of antibiotics, multiplicity of fractures, degree of fragmentation, medical problems, and drug and alcohol abuse. The adequacy of reduction and appropriateness of the fixation techniques were evaluated by analysis of the postoperative imaging studies. Postoperative occlusion and patient compliance were also included in the evaluation.

RESULTS

Of the 906 patients with 1,432 mandible fractures, there were 25 nonunion complications, for an incidence of 2.8%. Most patients with nonunion were men who had received the fracture as a result of an altercation. The nonunion was frequently noted in the body, and was almost twice as common (39% vs 17.6%) in patients with multiple fractures than in a randomly selected group who did not have the complication. Delayed treatment was noted in 8 of the patients, and teeth were present in the fracture line in another 8. Alcohol and drug abuse were prevalent, and 1 of 5 of the patients removed their fixation devices. Eight patients were believed to be stabilized inadequately, and 1 patient also had a poor reduction. Osteomyelitis was a common complication.

CONCLUSIONS

The incidence of nonunion appears to be unchanged over time regardless of the varied and presumably advanced methods of fixation and reduction. Multiple fractures were a contributory factor, and the body of the mandible appeared to be a common site. Many patients had osteomyelitis associated with the nonunion. Inadequate stabilization or reduction were important causes. Other suspected contributory factors included failure to provide antibiotics, delay in treatment, teeth in the fracture line, alcohol and drug abuse, inexperience of the surgeon, and lack of patient compliance.