title: Tomographic Evaluation of Mandibular Thickness on Premolar and Molar Regions Related to Monocortical Screws.
abstract: The aim of this study was to measure the thickness of the mandible from the external cortical plate to the teeth roots on premolar and molar regions using CT scan to determine the safety margin for the application of monocortical screws for internal rigid fixation. Thirty-one patients underwent CT-scan imaging for surgical planning. The images were used to measure bilaterally the distance from the external cortex of the mandible to the roots of teeth on premolar and molar region by means of Dental Slice software (Bioparts Prototipagem Biomedica, Brasília, DF, Brazil). Mean, median, standard deviation, one-way ANOVA and post hoc Tukey's test were used for statistical analysis. No statistical differences for thickness were found between right and left side (p = 0.1652). The mean thickness for the left side was 4.17 ± 1.68 mm and for right side 3.93 ± 1.49 mm. Increase in mandibular thickness from anterior to posterior regions in both sides was observed and statistical difference was found among the different groups according to the measured region (p < 0.05). The present results can predict the safety zone for the use of monocortical screws in the mandible, but the use of CT scan is imperative and individual analysis is desired owing to anatomical variations. Further studies with larger samples are necessary to confirm these data and should include other anatomic structures, different regions of mandible/maxilla, as well as other ethnic groups.
authors.affiliation: Department of Oral and Maxillofacial Surgery, São José College, Rio de Janeiro, Brazil.
authors.forename: Jonathan
authors.initials: J
authors.lastname: Ribeiro
authors.affiliation: Department of Implantology, Unigranrio University, Rio de Janeiro, Brazil.
authors.forename: Charles
authors.initials: C
authors.lastname: Marin
authors.affiliation: Department of Maxillofacial Surgery, Fluminense Federal University, Rio de Janeiro, Brazil.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Homsi
authors.affiliation: Department of Maxillofacial Surgery, Nova Iguaçu General Hospital, Nova Iguaçu, Brazil.
authors.forename: Hernando
authors.initials: H
authors.lastname: Rocha Junior
authors.affiliation: Department of Maxillofacial Surgery, Nova Iguaçu General Hospital, Nova Iguaçu, Brazil.
authors.forename: Luiz
authors.initials: L
authors.lastname: Magacho
authors.affiliation: Department of Maxillofacial Surgery, Nova Iguaçu General Hospital, Nova Iguaçu, Brazil.
authors.forename: Guto
authors.initials: G
authors.lastname: Fidalgo
authors.affiliation: Department of Maxillofacial Surgery, Nova Iguaçu General Hospital, Nova Iguaçu, Brazil.
authors.forename: Manuella
authors.initials: M
authors.lastname: Zanela
keywords: mandibular; screws; tomography