Evaluation of potential mini-implant insertion sites for maxillary skeletal expander: A computerized tomography study

Abstract

Objective: To estimate palatal bone thickness (PBT), inferior surface palatal bone density (ISPBD), superior surface palatal bone density (SSPBD), palatal soft tissue thickness (PST) and hard palate extension (HPE) in relation to maxillary dentition for maxillary skeletal expander (MSE) mini-implant insertion sites. Materials and Methods: Computerized Tomography images of 40 subjects were selected (19 male, 21 female) with mean age 23.12 years. The measurements of PBT, ISPBD, SSPBD, and PST were made at 14 different levels from incisive foramen at 2 mm intervals using BlueSky software. HPE was measured in relation to the distal surface of the maxillary second molar tooth. Statistical analysis was used to compare and correlate variables. Result: PBT, ISPBD, and SSPBD decrease from anterior to posterior region with a significant difference in PBT between anterior and posterior areas in the total sample and in males. PST showed no significant differences between anterior and posterior areas and between males and females. HPE located 4 mm anterior to the line tangent to the distal surface of the second molar. There was a positive relationship between PBT and PST in anterior regions of the palate and negative one in the posterior region. Conclusion: PBT decreased in the posterior direction. Anatomical variables measured at sites 13–19 mm from incisive foramen support MSE insertion locations. A significant positive correlation between PBT and PST was found in the anterior region of the palate while a negative correlation between these parameters was documented posteriorly. However, no correlation was reported between PBT and ISPBD except at 5 mm, and no correlation was detected between PBT and PST.