Use of reconstructed CT images for evaluation of the position of screw-type temporary anchorage devices implanted in the maxillary molar region

Temporary anchorage devices (TAD) have recently been employed for orthodontic treatment. I attempted to find the safest position for placing the screw-type TAD in the maxillary molar region. Using reconstructed CT images, I investigated the buccolingual and mesiodistal lengths of the interalveolar septums between the maxillary first premolar, second premolar, first molar, and the second molar. For the first and second molars, I measured the distance from the alveolar crest to the maxillary sinus. The results indicated that the safest position for placing a screw-type TAD was the interalveolar septum between the maxillary first molar and the second premolar at about a depth of 4-6 mm from the alveolar crest on the buccal side, and at about a depth of 2-6 mm from the alveolar crest on the palatal side. (author)