Métodos de fixação de fraturas mandibulares em cães: resistência mecânica à compressão

Abstract

Foi testada a resistência mecânica à compressão em 30 hemimandíbulas coletadas de cadáveres caninos. Dez. hemimandíbulas foram mantidas íntegras (grupo 1 = controle). As outras 20 foram submetidas inicialmente a fraturas oblíquas simples, entre o segundo e terceiro pré-molares e, posteriormente, imobilizadas por meio do emprego de resina acrílica aplicada diretamente sobre as superfícies dentárias em conjunto com o fio metálico interdental (grupo 2) ou interfragmentar (grupo 3). A análise estatística mostrou diferença significativa entre os grupos (Gl>G2>G3). Foi possível concluir que o método empregado no grupo 2, além de ser menos invasivo e não ter o perigo de danificar as raízes dentárias, é mecanicamente mais resistente do que o utilizado no grupo 3.

Ex vivo biomechanical analysis of two methods of osteosynthesis in canine mandibular fractures

“…The values found by Rahal et al (1998), Lewicki (2012), and Arzi et al (2016) for intact hemimandibles suggest that, although the plate and screw method has a higher compressive strength than other stabilization methods, post-operative care is still required, such as the use of liquid diets, feeding probes, and in some casesmuzzles, since no stabilization method can offer strength similar to strength of intact mandibles.…”

“…In Group 2, failure of the implants occurred through bone fissure of the caudal fragment at the fracture line in seven anatomical parts (87.5%; Figure 6) and implant deformation in one part (12.5%). Several biomechanical tests to evaluate the maximum strength of implants in mandibular fractures have already been performed, and the hemimandibles were used in several previous reports (RAHAL et al, Several biomechanical tests to evaluate the maximum strength of implants in mandibular fractures have already been performed, and the hemimandibles were used in several previous reports (RAHAL et al, 1998;MILLER et al, 2011;LEWICKI,2012;ARZIet al, 2016). Evans (1973) and Ashman and Buskirk(1987) demonstrated that there are no differences in the biomechanical and bioelastic properties of frozen bones when they return to room temperature.…”

“…This discrepancy may be related to the fixation having been performed in a bicortical manner. Rahal et al (1998) compared the mechanical compressive strength of intact and osteotomized hemimandibles between the 2nd and 3rd premolars stabilized with interdental steel wire associated with dental acrylic resin and inter-fragmentary cerclage associated with acrylic resin. According to their findings, themean resistancewas 48.26 kgf for intact mandibles, 15.9 kgf for acrylic resin associated with interdental steel wire, and 3.38 kgf for interfragmentary cerclage associated with acrylic resin.…”

“…In this experiment, the authors found a value of 48.25kgf for intact hemimandibles, differing from the strength to intact hemimandible of 102 kgf reported by Lewicki (2012). This difference suggests that the size of the animals interferes with their bone strength, since Rahal et al(1998) used animals weighing up to 17 kg, while Lewicki (2012) used animals weighing between 20 and 25 kg.…”

Análise biomecânica ex vivo de dois métodos de osteossíntese de ílio em cães

“…Testes biomecânicos são utilizados para avaliação da resistência óssea para enxertos (MACEDO et al, 1999;LUCAS et al, 2001;DINGEE, 2005), assim como para avaliação dos dispositivos de fixação em vários tipos de osteossínteses (RAHAL et al, 1998;LANZ et al, 1999;ANDERSON et al, 2002).…”