The Effects of Magnitude and Frequency of Distraction Forces on Tissue Regeneration in Distraction Osteogenesis of the Mandible

Abstract

Callus distraction has become an accepted treatment procedure to lengthen hypoplastic mandibles in humans. For this purpose, extraoral and intraoral devices have been applied successfully. The effects of the distraction vector, distractor stability, and rate and frequency of callus distraction on the regenerating tissues have been examined in various studies. In an experimental animal trial on pigs (n = 12), a newly developed microhydraulic osteodistractor was tested. The animals were evenly assigned to two groups to perform a continuous and noncontinuous osteodistraction of the mandible. Initially, the forces necessary to distract the pig mandibles were recorded from a noncontinuous distraction procedure; the results were then used to perform continuous bone distraction. Besides testing the new distractor, the study proved that in continuous osteodistraction, intramembranous bone regeneration occurred, whereas in noncontinuous osteodistraction the bone regeneration process followed a chondroid ossification. In continuous osteodistraction, the bone regeneration proceeded at a higher speed with the lower distraction forces compared with noncontinuous distraction, thereby reducing the consolidation period. Clinical and microscopical results are presented.

Biomechanical Configurations of Mandibular Transport Distraction Osteogenesis Devices

“…[69][70][71] However, the hydraulic pressure of the activation system is variable during the distraction period, for both continuous and especially incremental activation processes. 70,72 In general, the hydraulic activation system does not have a constant relationship between pressure applied at the remote control and the amount of disc displacement, except if both the hydraulic activation system and the remote control have the same internal diameter. 69,71,73 This activation system has been mainly used for monofocal distraction by attaching the cylinder and the piston directly to the edges of the bone and taking advantage of the relative displacement between them.…”

“…69,71,73 This activation system has been mainly used for monofocal distraction by attaching the cylinder and the piston directly to the edges of the bone and taking advantage of the relative displacement between them. [70][71][72][73] The device has also been used for MBT by using a titanium reconstruction plate to stabilize both mandibular segments (Fig. 5D), fixing the cylinder to one side of the defect and projecting the transport unit attached to the end of the piston.…”

Temporary distraction and compression of a diaphyseal osteotomy accelerates bone healing

“…In consecutive studies it would be interesting to see whether a continuous distraction by a motordriven device or a longer distraction period and a very slow compression rate could further improve the positive effect of the temporary distraction and compression procedure. 18 A limitation in regard to clinical application is that this method can only be used if a fracture is treated by external fixation.…”

Avaliação da densitometria óssea de tecido ósseo neoformado após distração osteogênica mandibular

“…Aparentemente, com uma aplicação de força contí-nua e de menor intensidade, a regeneração óssea ocorre numa velocidade mais rápida e apresenta um período menor de consolidação 15 . Também há menor possibilidade de modificações degenerativas do nervo alveolar inferior quando uma força contínua e de menor intensidade é aplicada na mandíbula 11 .…”

“…Os efeitos do vetor da distração, a estabilização do distrator e a intensidade e freqüência da distração do calo ósseo são variáveis que têm sido examinadas em vários estudos 15 . Há diversas formas de avaliação da qualidade do tecido ósseo neoformado, obtido por meio da técnica de distração osteogênica.…”