"Safe zones": a guide for miniscrew positioning in the maxillary and mandibular arch

The aim of this study was to provide an anatomical map to assist the clinician in miniscrew placement in a safe location between dental roots. Volumetric tomographic images of 25 maxillae and 25 mandibles taken with the NewTom System were examined. For each interradicular space, the mesiodistal and the buccolingual distances were measured at two, five, eight, and 11 mm from the alveolar crest. In this article, measurements distal to the canines are presented. In the maxilla, the greatest amount of mesiodistal bone was on the palatal side between the second premolar and the first molar. The least amount of bone was in the tuberosity. The greatest thickness of bone in the buccopalatal dimension was between the first and second molars, whereas the least was found in the tuberosity. In the mandible, the greatest amount of mesiodistal dimension was between first and second premolar. The least amount of bone was between the first premolar and the canine. In the buccolingual dimension, the greatest thickness was between first and second molars. The least amount of bone was between first premolar and the canine. Clinical indications for a safe application of the miniscrews are provided, as well as the ideal miniscrew features.