Identifying Complications in Distraction Osteogenesis.

Distraction osteogenesis as an alternative to conventional rehabilitation surgery revolutionized the addressing of critical-sized defects in children and adults. Considering the advantages, the method was preferred by many surgical units across the world to prevent additional surgeries, donor site morbidities, prolonged anesthetic use as well as to minimize the graft-associated reactions.[1] Literature cites that the complication in relation to distraction osteogenesis is much similar to that of the other standard treatment procedures; up to 40% were noted.[12] The number of devices placed increases, as in bilateral distractors, the chance of complications increases. The complications that arise with distraction osteogenesis of the jaw bone (DOJB) can be broadly divided into three groups - intraoperative, intradistraction, and postdistraction complications.[1]

The intraoperative complications relate to the surgical procedure itself (e.g., malfracturing, incomplete fracture, nerve damage, and excessive bleeding) and device-related problems (e.g., fracture and unstable placement). During placement, owing to poor surgical planning, especially when surgery is planned with two-dimensional radiographs, chance of missing crucial aspects would cause improper disjunction. The young bones often split as a green stick fracture rather than divide. This causes severe complication. Poor surgical planning and managing of situation would cause problems with fracture. This also could severely influence the vector placement. Missing out crucial vessels could cause bleeding or nerve damage too. Device-related problem is another crucial issue. Fatigue, poor adaptation, and unrealistic vector placement may lead to accumulation of stress inside the device that may lead to subsequent fracture. This is crucial, especially when patient do not comply with instructions.[123]

The intradistraction complications relate to the problems that arise during distraction process (e.g., infection, device problems, pain, malnutrition, and premature consolidation). During distraction, the speed of distraction is crucial. If faster, there would be potential failure of treatment by wound dehiscence. Unrealistic speed should be avoided. An opening of 1 mm/day or 2 is ideal depending on age and location as well as type of distractors. The spectrum of the symptoms and signs varies and often has been called as “Regenerate Disorders.” Inadequate tension applied to the neo-osteoid tissues causes these spectrums of disorders ranging from hypotrophic regenerate to hypertrophic regenerate.[123]

Maintenance of oral hygiene is essential, and patient compliance is crucial. Malnutrition should be avoided. As the oral tissues are composed of bone, nerves, blood vessels, and other tissues, regeneration rate of different tissues often is not synchronized with that of jaw bones. This may give rise to complications including damages to nerves, manifesting a hypesthesia and anesthesia. The neurosensory deficits are serious and exist in a wide spectrum of variability ranging from no clinical effect to permanent neurosensory in up to half of the patients.[1234]

Postdistraction complications concern the late problems arising during the period of splinting and after removal of the distraction devices (e.g., malunion, relapse, and persistent nerve damage). The distractor, by reason of accumulation of stresses, may be fractured. This should be closely monitored. The problems occur mostly due to improper vector control. Vector control perhaps is the single largest factor that differentiates DOJB from other conventional procedures which are static while the DOJB is a dynamic healing phenomenon, in which, patient is an active participant. Poor vector control causes open bite and midline shift. Often these problems are diagnosed earlier and treated by simple methods such as elastic band traction or early removal of distractors. Overcorrections and undercorrections in DOJB is a matter of contention and has to be addressed based on specific case-by-case basis. Long-term changes in mandibular condyles due to DOJB is another specific area that needs to be borne in mind.[1234]

Although DOJB offers unconditional advantages, it requires diligent skill and training to avoid complications. In hands of a skilled surgeon with appropriate planning, DOJB serves as an excellent tool for maxillomandibular rehabilitation and reconstruction.