The effect of two rates of mandibular distraction osteogenesis on the inferior alveolar nerve : an experimental study in dogs

الملخص EN

Objective : The aim of this work was to study the effect of two rates of mandibular distraction osteogenesis (DO) on the inferior alveolar nerve (IAN).

Material and Methods : Osteotomy was made anterior to the right mandibular first molar of 8 healthy adult dogs used in this study.

The mandibles in 8 dogs were lengthened 10 mm with 2 different rates of distraction (1mm / d [n = 4] and 2 mm /d [n = 4]) ; the opposite non-distracted side was considered control group .The dogs were killed at 2 weeks after completion of distraction.

The inferior alveolar nerve specimens from all animals were harvested and processed for histological evaluation.

Results : The mandibles were lengthened successfully in both groups.

Morphologic changes in the inferior alveolar nerves were observed when compared with the no distracted controls.

Moreover, signs of nerve degeneration, and decrease in the number of axons, were more extensive and prominent in those nerves distracted at a rate of 2 mm / d.

Conclusion : The results of this study suggest that a rate of 1 mm per day appears to be relatively safe for the inferior alveolar nerve during mandibular distraction.

However, a higher rate of distraction seems to result in greater damage to the nerve.

Thus, rapid mandibular distraction may not be advisable.