Le Fort III distraction osteogenesis: modification of the intraoral splint in the rigid external distraction.

Le Fort III distraction osteogenesis (DO) is a useful procedure for treating midface hypoplasia. The external distraction system has the advantage of allowing modification of the distraction vector during the activation period. This system needs an intraoral splint for the anchorage points. The intraoral splint has an important role in conducting the distraction force to the midface and in forming the advancement vector. The authors developed a modified type of splint to improve the outcome of Le Fort III DO.The intraoral splint is composed of a modified headgear face bow, molar bands, and a palatal acrylic plate without covering the teeth. Four suspension wires were applied to reinforce the stability. The zygomatic bones and the loops of the splint are selected as 4 anchorage points for Le Fort III DO. This procedure was applied to 2 patients.The midface had an advancement of more than 20 mm in both patients. The dental movement of the upper incisors and the upper first molar was minimal.The dental effect was nearly absent. The amount and vector of distraction could be decided under direct observation without blocking the dental occlusion. The vector of distraction could be adjusted during the activation period. The results of DO were satisfactory.