Bone thickness of the palate for orthodontic mini-implant anchorage in adults

Abstract

The palate is a suitable site for the placement of orthodontic mini-implants. This study was conducted to assess the bone thickness of the palate to provide a more reliable guide for mini-implant placement. Computed tomographic records of 18 adults (9 men, 9 women) 18 to 35 years old (mean age, 26.8 +/- 4.0 years) were used to measure the bone thickness of the midpalatal area and its vicinity posterior to the incisive foramen. Bone thickness was measured at 80 coordinates at regular mediolateral and anteroposterior intervals along the midpalatal suture. After the mean, minimum, and maximum values were obtained for the entire group and for the male and female groups, mediolateral and anteroposterior comparison was done, and the differences between sexes were evaluated. Individual variations were so great that high-resolution computed tomographic images are recommended for safety. Significant differences were seen between the male and female groups. The midpalatal area within 1 mm of the midsagittal suture had the thickest bone available in the whole palate. The thickness tended to decrease laterally and posteriorly. Maps of mean palatal bone thickness were made for visual comparison of placement locations and for selection of the mini-implant length. When a mini-implant could deviate from the midpalatal area by more than 1 mm, we recommend placing it not far posteriorly or using a shorter mini-implant.