RESUMEN
BACKGROUND: Mandibular Sagittal Split Osteotomy (MSSO) is a popular technique in orthognathic surgery used both to advance and to retreat the mandible. However, MSSO may incur in important complications, such as bad splits and sensorineural injuries. Knowing the location of the fusion between the buccal and lingual cortical (FBLC) in the mandibular ramus and the bone thickness in the region where osteotomies will be performed is determinant in MSSO planning to avoid complications. The aim of this study was to document and evaluate possible differences between sexes regarding the location of the FBLC in relation to the superior cortical of mandibular foramen (MF) and bone thickness in the region of interest for MSSO in a Brazilian population. MATERIAL AND METHODS: Eighty five cone-beam Computed Tomography (CBCT) scans were used to perform linear measurements to determine the location of the FBLC. Bone thickness from the mandibular canal (MC) to the cortical external surfaces and the diameter of the MC were measured at three different points: mandibular ramus (A), mandibular angle (B) and mesial of the second molar (C). RESULTS: The FBLC was located at a mean distance of 8.3 mm from the superior cortical of the MF in males and 8.1 mm in females. There was no difference between males and females regarding the mean bone thickness from the MC to the buccal external surface at all the points investigated (p>0.05). Bone thickness from the lingual external surface to the MC was bigger among females than males in regions B and C (p < 0.05). The diameter of the MC was bigger among males in regions B and C. CONCLUSION: Sexual dimorphism regarding mandibular bone thickness but not regarding the location of FBLC was present. This fundamental knowledge may assist to the panning of MSSO.
Asunto(s)
Tomografía Computarizada de Haz Cónico , Mandíbula/diagnóstico por imagen , Osteotomía Sagital de Rama Mandibular , Brasil , Femenino , Humanos , Masculino , Mandíbula/anatomía & histología , Boca , Caracteres Sexuales , Lengua , Adulto JovenRESUMEN
Introduction: Plain radiographs are still routinely used for diagnosis in dentistry. They allow the assessmentof anatomical structures and their variations, and the detection of abnormalities in the region assessed. Theaim of this research was to determine the width and height distances of the frontal sinus on posteroanteriorskull view of Brazilian subjects. Materials and methods: The sample was composed of 158 posteroanteriorfacial radiographs (Caldwell projection). It was measured the height and width of the frontal sinus, both sides,under a standardized protocol, using rules and a viewer box. The relationship between frontal sinus size andside of the face, and size and age were evaluated. Results: Thirteen radiographs were excluded (six of unilateralfrontal sinus, two agenesies, and five showing totally individualized chambers). The final sample studied was of145 subjects. The mean values obtained were a 68 mm for latero-lateral and 39 mm for superoinferior distances.In 39.3% cases both sides were approximately equal or had the left chamber larger than the right one. Therewas a significant correlation between width and height of frontal sinus (Spearman coefficient), however therewas no significant difference among the age groups studied (Kruskal-Wallis, p > 0,05). Conclusion: There is agreat anatomical variety of frontal sinus in this population. The left cavity of frontal sinus is larger or equal tothe right one and the age group differences was not significant regarding the size of the frontal sinus.