Dental CT and orthodontic implants: imaging technique and assessment of available bone volume in the hard palate

Purpose: Palatal implants (PI) have been introduced for orthodontic treatment of dental and skeletal dysgnathia. Due to the restricted amount of bone in this region, precise preoperative anatomic information is necessary. The aim of this study was to determine whether dental CT could serve as a tool to locate the optimal size and position for orthodontic implant placement. Materials and methods: In 32 patients, where palatal implant placement was planned, axial CT scans of the maxillary bone were acquired. Using a standard dental software package (Easy Vision dental software package 2.1, Philips; Best, The Netherlands), paracoronal views were reconstructed and measurements of palatal bone height in 3 mm increments, dorsally from the incisive canal, were performed in the median and both paramedian regions. Results: The overall mean bone height was 5.01 mm (S.D. 2.60), ranging from 0 to 16.9 mm. The maximum palatal bone height was 6.17 mm (S.D. 2.81) at 6 mm dorsally from the incisive canal. Due to the lack of adequate bone (less than 4 mm), implant placement was not performed in 3 cases (7%). In the remaining 39 cases (93.0%), primary implant stability was achieved and complications, such as perforation of the palate, could be avoided. Conclusion: The results demonstrate that dental CT promises to be a valuable tool in evaluating the potential and optimal size and site for orthodontic implant placement.