A simplified method for measurement of palatal bone thickness to select the optimum length of orthodontic mini-implant

The palatal bone is a suitable site for mini-implant placement due to it being a “rootless area” with dense bone. This application has increased with mini-implant-assisted rapid palatal expansion becoming the preferred method of expansion. It is necessary to measure the vertical bone height with a reasonable accuracy, at the implant insertion site, to utilize the maximum available bone support, and to avoid the risk of perforations. As an accepted method, full-volume cone-beam computed tomography (CBCT) scan is advised for the same. This requires an additional procedure, further, radiation exposure, and cost to the patient. The aim of the study was to establish the utility of lateral cephalogram as a simple and reliable method to measure palatal bone thickness for placement of mini-implants in the 1 st premolar and 1st molar region, which are the most common sites of mini-implant placement. Materials and Methods A total of 30 CBCT scans and digital lateral cephalograms of patients were selected and analyzed at the 1 st premolar and molar region and were statistically evaluated using Student’s t-test and Wilcoxon rank-sum test. Results The results obtained indicated a highly significant correlation between the measurements obtained on lateral cephalograms at both the 1 st premolar and 1 st molar areas, P < 0.001. Conclusion The data presented show that lateral cephalometry provides a reliable assessment of the quantity of vertical bone for paramedian insertion of a palatal implant.