Preoperative Diagnostic for Palatal Implants: Is CT or CBCT Necessary?

Objective: To evaluate (a) the diagnostic value of lateral radiographs and (b) whether computed tomography (CT) or cone beam computed tomography (CBCT) is necessary in preoperative diagnostics for orthodontic anchorage implants. Patients and Methods: We reviewed all patients who had presented for insertion of a palatal implant between January 2003 and December 2007 at the University Hospital Mainz. On the basis of lateral radiographs, the palatal bone was assessed as follows: (a) sufficient (bone height > 4 mm in the implant axis), (b) ambiguous, or (c) insufficient (bone height < 4 mm in the implant axis). In group A the surgical insertion procedure was performed without further radiological investigation. Group C required other types of anchorage. In cases of an ambiguous bone situation (group B), further diagnostic procedures (CT/CBCT) were performed. Results: During the observation period, 105 patients were screened. Fourteen patients opted for alternative treatment leaving 91 patients for final evaluation. In 89 patients (97.8%), the lateral radiographs showed sufficient bone in the vertical dimension. In all of these cases, the availability of sufficient bone was confirmed intraoperatively. Further investigations were performed in two patients (2.2%) of group B (one CT, one CBCT). Finally, one patient had insufficient bone whereas the second had sufficient bone. Conclusions: Nearly 98% of the patients included in this study had sufficient bone for palatal implant insertion. Lateral radiographs permit correct and reliable evaluation of the quantity of bone in preoperative diagnosis of palatal implants. Additional imaging (CT or CBCT) is only required in rare cases of borderline dimensions.