Inferior Level of Maxillary Sinus and Cortical Bone Thickness at Maxillary Posterior Quadrant, in Three Different Growth Patterns: 3D-Computed Tomographic Study

Abstract

Objective of this retrospective study was to measure cortical bone thickness and lowest level of maxillary sinus at maxillary posterior quadrant in different growth pattern (hypodivergent, average, and hyperdivergent) at prospective microimplant placement sites in order to understand both safety and stability aspects of microimplant placement by using cone-beam 3-dimensional computed tomographic images. In posterior quadrant, vertical distance from cementoenamel junction to lowest level of maxillary sinus at interradicular region was measured. Buccal cortical bone thickness was measured at 3 different vertical levels at interradicular space. The cortical bone thickness was found more at sinus floor level and above it than below the sinus floor. In perspective of miniscrew placement, study shows that maxillary sinus floor is safer with average and hyperdivergent growth pattern than hypodivergent growth pattern. In the proximity of maxillary sinus floor, 1 mm or more cortical bone can be expected in maxillary posterior region in average and hyperdivergent growth patterns. However, it was thicker in hypodivergent than hyperdivergent growth patterns. Hypodivergent patients require either more horizontal insertion (more parallel to occlusal plane) or shorter length of miniscrew to avoid damage to maxillary sinus.

‘Comparison and correlation of the maxillary sinus dimensions in various craniofacial patterns: A CBCT Study’

“…In confirmation with our study results, previously only one study has been reported in literature stating hypodivergent growth pattern shows reduced basal bone width and needs more horizontal insertion or reduced length of the implant due to proximity to the sinus floor. 24 Further in our study, when the mean A-P depth and mean M-D width was compared among the 3 study groups, Group-2 had the longest mean A-P depth and longest mean M-D width of the maxillary sinus, whereas Group-1 had the shortest mean A-P depth and mean M-D width. Mean maxillary sinus volume was statistically significantly less in Group-1 when compared to other groups.…”

Comparative evaluation of accuracy and stability of Orthodontic temporary anchorage device with and without the use of Mini-implant placement guiding device (MIG-20) in adults- An in vivo study

“…Vibhute PJ et al, measured the thickness of cortical bone using computed tomography and found out that the cortical bone thickness is increased at the sinus floor level and above it than below the sinus floor. 18 The safer zone for placement of the implant concerning maxillary sinus level varies in different growth patterns, as was the finding of Vibhute PJ et al…”

‘Comparison and correlation of the maxillary sinus dimensions in various craniofacial patterns: A CBCT Study’

“…In confirmation with our study results, previously only one study has been reported in literature stating hypodivergent growth pattern shows reduced basal bone width and needs more horizontal insertion or reduced length of the implant due to proximity to the sinus floor. 24 …”