Radiographic evaluation of mandibular canal and its relation to occlusal Angle class

• Grant number: 11/09232-6
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: December 01, 2011
• End date: September 30, 2012
• Field of knowledge: Health Sciences - Dentistry - Dental Radiology
• Principal Investigator: Felippe Bevilacqua Prado
• Grantee: Raisa Zago Falkine
• Host Institution: Faculdade de Odontologia de Piracicaba (FOP). Universidade Estadual de Campinas (UNICAMP). Piracicaba , SP, Brazil

Abstract

Injuries of the inferior alveolar nerve during dental procedures and surgery can be avoided with knowledge of the anatomical location of the mandibular canal in relation to the apex of the roots of lower permanent molars. The position of a mandibular canal can vary depending on the occlusal class of the individual (Angle Class I, II, and III). Studies of this nature have rarely been discussed. Objectives: to evaluate, by means of panoramic radiographs, the anatomical differences in the location of the mandibular canal in relation to the apex of the lower permanent molars and the base of the mandible according to the classification of Nortjé et al. (1977). To relate the type of positioning of the mandibular canal to the Angle classes I, II, and III in the individuals evaluated. Materials and methods: 900 panoramic radiographs (300 of Class I, 300 of Class II, and 300 Class III) will be evaluated, is that each group contains 150 female individuals and 150 male individuals, completely edentulous, with ages ranging from 18 to 51 years. The radiographs of individuals will be divided according to occlusal Angle classes based on cephalometry (ANB angle measurement). These same individuals will have their bilateral mandibular canal measured and classified according to their location relative to the root apex of the lower molars and the base of the mandible in panoramic radiographs according to the classification of Nortjé et al. (1977). To perform this classification, the distance measurements from the mandibular canal to the apex teeth and to the base of the mandible will be performed using the ImageLab2000® software. The intra-observer reproducibility of measurements on radiographs will be evaluated using the coefficient of variation. Differences between left and right sides of the mandible and the gender of the individual will be analyzed with paired t-tests for paired groups with Class I, II, and III malocclusion. Differences between the groups will be examined with statistical significance based on an independent t-test. The data will be tabulated and submitted to the Student t test with significance level of 5% by BioEstat 5.0 software (Fundação Mamiramuá, Belém, PA). The repeatability of the test will be performed by intraclass correlation coefficient (ICC).(AU)