Anatomic site evaluation of the palatal bone for temporary orthodontic anchorage devices

Objectives: The aim of the present study was to assess the micromorphologic characteristics of the palatal bone from an implantologic standpoint.
Materials and Methods: The material consisted of tissue blocks of autopsy material from 22 subjects (18 males, three females) between 18 and 63 years of age. The specimens comprised the anterior median palatal region from 5 to 10 mm behind the incisive foramen. They were prepared in the transversal plane according to ground thin-section technology. The midpalatal area as well as an area of 3 mm bilateral to the midline were assessed, and a classification of quantitative palatal bone availability was developed.
Results: The findings could be divided into three classes: (1) class I palatal bone consists almost of compact bone; (2) class II cortical bone layer on oral and nasal sides of palate, broad compact bone in the suture area (≥3 mm), loose trabecular bone lateral to the suture area; and (3) class III cortical bone on oral and nasal side, thin compact bone in the suture area (<3 mm) and loose-structured trabecular bone lateral to the suture area. In most sections (72.7%), class I characteristics were found (16 subjects). 18.2% of sections were assigned to class II (four subjects) and only 9.1% of sections were assigned to class III (two subjects).
Conclusion: These results document that in most cases a good primary stability of temporary orthodontic anchorage devices should be achieved in the midpalatal and paramedian area of the anterior palate, as the bone quantity available is high.