Análise tomográfica do espaço interalveolar e da espessura da cortical óssea vestibular na região parassinfisária de mandíbulas humanas adultas

• Autor(a) principal: Uzêda, Sandra de Quadros [UNIFESP]
• Data de Publicação: 2009
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNIFESP
• Texto Completo: http://repositorio.unifesp.br/handle/11600/8946
• topic: Alvéolo dental; Fixação de fratura; Morfologia; Parafusos ósseos; Tomografia; Mandíbula; Tooth Socket; Fracture Fixation; Bone Screws; Tomography; Mandible

Objective: To assess the thickness of the mandibular bone in the interalveolar space corresponding to the dental units 3.3; 3.4; 3.5; 4.3; 4.4, 4.5, in the mental foramen region and the thickness of the bone cortical in the same region and to analyze the viability of fixating Champy miniplates (System 2.0®) with monocortical screws in the direction of the interalveolar space of the units 3.3, 3.4, 3.5, 4.3, 4.4, 4.5. Methods: Fifty dry mandibles of dentate adults (25 females and 25 males) aging from 33 to 87 years were used. These catalogued mandibles were acquired from the Human Anatomy Laboratory from the University of State of Bahia, state of Bahia, Brazil. Mandibles with malformations or macroscopic pathological changes in the body of the mandible were excluded. Initially we identified a point (P) located 1.25mm above the upper margin of the mental foramen of the mandible (right side: P´ and left side: P”). This distance corresponds to half of the width of the bridge of the titanium miniplate, System 2.0® that is generally used above the mental foramen in the Champy technique, whose objective is to eliminate tension zones when treating mandibular fractures. After identifying the (P) point, the mandible was placed over an acrylic base horizontally with a vertical rod, planned and constructed to identify the points A´, B´, C´ and A”, B” and C” which correspond to the units 4.3; 4.4; 4.5 and 3.3; 3.4; 3.5. After marking the points, the interalveolar distances were measured by indirect analysis using axial computed tomography (CT) cuts. After delimiting and perforating the points, these were filled with previously heated gutta-percha that served as a marker in the CT cuts. Five (05) mandibles of the sample were cut in a way as to allow direct biometry with the objective of comparing and validating the CT measurements. Results: The data show that the thickness of the vestibular cortical bone is not enough to adequately implant and fixate the screws even though the interalveolar distance is sufficiently safe to introduce them. The data point towards a deficiency in the bone support required to generate the procedures of the Champy technique since the anatomy of the mandible does not present elements that support placing the plates and screws in the way recommended by the technique. There is no adequate bone support to promote the necessary stability.