Forces on Implants Supporting Overdentures: A Preliminary Study of Morphologic and Cephalometric Considerations

It is usually suggested that loading forces be transmitted to implants in the vertical direction. In 44 subjects treated with mandibular implants and overdentures, the inclination of the implant axis relative to the occlusal plane of the corresponding prostheses was measured by means of cephalometric radiographs. The degree of mandibular atrophy was also assessed. Peri-implant parameters such as plaque index, bleeding scores, and probing depths were registered on four implant sites. About 70% of the implants showed a buccal inclination, 11% showed a lingual inclination, and only 19% were found with an angle of 90 degrees. After an observation period of 5 years, no positive relationship between inclination of the implant axis, mandibular atrophy, and peri-implant findings could be established. Aspects of facial morphology and the interalveolar relationship of both jaws should be considered additional parameters and should be included in investigations concerning functional dynamics of removable dentures. Keywords: cephalometry, implants, mandibular atrophy, overdentures