[Controlled gradual lengthening of the mandible after osteotomy]

The procedures used to correct large discrepancies in the length of the mandibular body are described and experimental results are reported. The technique is realized using an orthodontic applicance that permits the progressive lengthening, after osteotomy of the mandibular body and also retains the approximation of the resected mandibular segments. Two dogs were used for the experimentation, achieving mandibular body lengthening of 5 and 15 millimeters. The bone neoformation was studied hystologically by means of microradiography and tetracyclines induced fluorescence. The surgical technique was carried out without damage to the mandibular nerve. The hystological examination shows no conspicous alteration of the nerve fibres.