Cerclagem com abraçadeira de náilon ou de fio de aço no reparo de fraturas experimentais de sínfise mandibular em gatos
Acta Scientiae Veterinariae
Cerclagem com abraçadeira de náilon ou de fio de aço no reparo de fraturas experimentais de sínfise mandibular em gatos
Autor Correspondente: Marina Gabriela Monteiro Carvalho Mori da Cunha | [email protected]
Palavras-chave: cirurgia oral, implante, felino, cicatrização sinfiseal
Resumos Cadastrados
Resumo Inglês:
Background: The mandibular symphysis is a true joint with a fibrocartilage disc stabilizing both ramus of mandible. The
mandibular fracture occurs in 15% of all cases of fracture in cats, and of these, 73% correspond to fracture of the mandibular
symphysis. There is a technique for stabilization of symphysis fracture using a nylon cable tie band, however it is necessary to
perform two lateral incisions in the oral mucosa besides divulsion of subcutaneous tissue, performing a tunnel so that the band
can be passed from one side to another. Thus, this study aimed to evaluate an alternative technique of fixation with nylon cable
tie band in mandibular symphyseal fractures of cats and compare the effectiveness, stability and complications between
implants of nylon cable tie band and stainless steel wire.
Materials, Methods & Results: Twelve cats were undergone to experimental mandibular symphyseal fractures and were
randomly separated in two groups according on type of implant used for osteosynthesis. For performing the cerclage, was used
nylon cable tie band in the cats of the N group and stainless steel wire in the cats of A group. Cats were undergone to daily oral
inspection and radiographic exams at 0, 15, 30 and 45 days post surgery. Radiografic analysis was performed by two evaluators
and used the average among them. This scale ranged from 0 to 4, with grade 0 classified as absence of bone resorption around
the implant and the mandibular symphysis, grades 1, 2, 3 and 4, when that bone resorption was mild, moderate, severe or very
severe respectively. There were statistic differences in the radiographic evaluation between groups, only at 15 days, which
Group A presented higher bone resorption than group N. There was a significant effect between time and degree of bone
resorption in both groups. Adapted technique was feasible and easy to be performed. Fracture stabilization was effective and
rigid fixation and appropriate occlusion was achieved in both groups. Two cats from group N presented sinus at 36 and 42 days
after surgery.
Discussion: The alternative technique of fixation of the nylon cable tie bands was less invasive than the technique described
previously, since only one incision was necessary for implant placement and did not require divulsion of tissue. All animals
showed bone resorption around the implant and between mandibular symphysis. Due to evidence of progressive feature, it is
suggested that bone resorption is influenced by the pressure exerted by the implant in the bone, compressing the periosteum
and affecting the collateral vascularization. It is suggested that group A has shown greater bone resorption in time 15 and 30
days due to the increased pressure exerted by the implant between the bone fragments. Only at 45 days post stabilization the
N group showed higher bone resorption than group A, so it is possible that this difference occurred due to progressive
accumulation of foreign bodies in the tunnel formed by implant, predisposing to bacterial contamination. Another hypothesis
is that because the surface of the nylon band is wider, therefore overlaps with the greater bone area, resulting in greater longterm
resorption. It is possible that the sinuses were formed only in N group due to the tunnel formed by the implant allowing
communication of the oral cavity with the subcutaneous ventral mandibular and the passage of oral bacteria into the subdermal
tissue. Nylon cable tie band as implant is an effective alternative for osteosynthesis of mandibular symphyseal fractures in cats,
nevertheless it can not remain for a longer time due to risk of complications, as sinus formation.
