Nasal cavity perforation by palatal implants: false-positive records on the lateral cephalogram.

Twenty percent of palatal implants projecting beyond the nasal floor were false-positive records on the postoperative lateral cephalograms. Despite CT scans, 10% of the implants placed caused fenestration of the nasal cavity by histologic evidence. If the palatal complex was perforated, intraoperative probing with a periodontal probe did not confirm the perforation. Bone perforations up to 1.3 mm did not necessarily result in frank perforation of the nasal mucosa. Two-dimensional images could not be related to actual penetrations into the nasal cavity.