Bone Lengthening in the Craniofacial Skeleton

TLDR

Bone lengthening by cortical fracture and gradual distraction of callus is well established in enchondral bones of the extremities. This study aimed to apply these principles to the membranous bone of the craniofacial skeleton using the growing dog mandible as a model. Six five‑month‑old mongrel dogs underwent a unilateral, periosteal‑preserving angular corticotomy with an external minilengthening device fixed perpendicular to the corticotomy; after 10 days of fixation, the mandible was lengthened 1 mm/day for 20 days and then maintained for 56 days before sacrifice. Anthropometric and histological analyses confirmed bone lengthening and new cortical bone formation in the expanded areas.

Abstract

The process of bone lengthening by cortical fracture and gradual distraction of callus has become well established in the enchondral bones of the extremities. In this study the principles of bone lengthening were applied to the membranous bone of the craniofacial skeleton using the growing dog mandible as a model. Six mongrel dogs five months of age were studied. A unilateral, periosteal-preserving angular corticotomy was performed, and an external minilengthening device was fixed to the mandible perpendicular to the corticotomy. After 10 days of external fixation, the mandible was lengthened 1 mm/day for 20 days and then held in external fixation for 56 days (8 weeks) after which all dogs were killed. Anthropometric measurements and histological analysis of the specimens confirmed that bone lengthening had occurred and that new cortical bone was formed in the expanded areas.