Documentation of the Incidents Associated with Mandibular Distraction: Introduction of a New Stratification System

BACKGROUND This article aims to assess the spectrum of unfavorable events or incidents encountered during mandibular distraction and to evaluate the difference in the incident rates among the following treatment groups: (1) native bone distraction using an external device, (2) native bone distraction using an internal device, and (3) grafted bone distraction using an external device. METHODS This retrospective study examined the records of 141 patients treated by mandibular distraction over a 16-year period. Of the total 141 patients, 56 underwent unilateral mandibular distraction and 85 underwent bilateral mandibular distraction, contributing to a total of 226 sided distraction procedures. The number of procedures performed on native bone using external devices was 149, versus 41 internal devices. There were 36 distractions performed on grafted bone with external devices. Incidents were broadly classified into three groups based on a severity index. A minor incident was one that resolved satisfactorily with minimal or no invasive intervention. A moderate incident was one that resolved satisfactorily with moderate clinical intervention. A major incident was one that did not resolve or could not be resolved with surgical intervention, and compromised treatment outcome. RESULTS The major incident rate was 5.31 percent (total of 226 distraction procedures). A higher rate of major incidents was observed when distracting grafted bone. The overall minor incident rate was 26.99 percent and the moderate incident rate was 20.35 percent. CONCLUSION Mandibular distraction can be considered a safe and predictable procedure for lengthening/augmenting the mandible in patients with lower jaw deficiencies.