Could the median-palate accommodate wide-bodied implants in order to support maxillary over-dentures? A radiomorphometric study of human cadavers.
BACKGROUND
Atrophy of the alveolar bone is an irreversible multifactorial phenomenon, the rate of which varies between individuals and between the jaws. This atrophy of the alveolar ridges presents severe limitations for the oral rehabilitation of the edentulous patients and poses a clinical challenge to the prosthodontists and implant surgeons. The present research aimed to investigate whether the median-palate of elderly edentulous subjects is anatomically suitable for implant placement.


METHODS
A total of 32 samples were harvested from the maxillae of 16 human cadavers. One dentate male subject was included for contrast. Bone quality and quantity were analysed at two regions: the median-palate and the edentulous maxillary alveolar ridge. Samples were scanned through micro-CT, and the region of analysis (ROA) identified and dissected. Bone volume to tissue volume ratio (%BV/TV), trabecular thickness (Tb.Th), trabecular number (Tb.N), trabecular separation (Tb.Sp) and trabecular bone pattern factor (Tb.Pf) were evaluated for the two regions using Skyscan CTAn(®).


RESULTS
The results of bone volume fraction obtained from CTAn(®) of the median-palatal region show higher values than the respective premolar sites in 12 of 15 (80%) edentulous samples. However, this difference was statistically non-significant (P = 0.06). Similarly, the trabecular number for 10 of 15 samples (66.6%) from the median-palate shows greater values than the respective premolar site (P = 0.07). Trabecular thickness of 10 of 15 (66.6%) premolar samples is larger than in the median-palatal region. However, these differences were also statistically non-significant (P = 0.25). Statistically significant difference (P = 0.04) was found between the Tb.Sp values of the two regions.


CONCLUSIONS
The results indicate that the anterior median-palate is structurally better than their respective maxillary premolar region in elderly edentulous persons, and an implant can be placed to anchor an overdenture. The best site for a wide-body implant was established to be 6-8 mm posterior to the incisive foramen in elderly edentulous patients.
Oral Implantology Research Group, Faculty of Dentistry, Sir John Walsh Research Institute, University of Otago, Dunedin, New Zealand.
Allauddin
A
Siddiqi
Jules A
JA
Kieser
Rohana K
RK
De Silva
Andrew
A
McNaughton
Warwick J
WJ
Duncan
D000368:Aged; D000369:Aged, 80 and over; D016301:Alveolar Bone Loss / Q000000981:diagnostic imaging*; D002102:Cadaver; D019094:Dental Prosthesis, Implant-Supported; D003828:Denture, Overlay; D005260:Female; D006801:Humans; D007575:Jaw, Edentulous / Q000534:rehabilitation*; D008297:Male; D008437:Maxilla / Q000601:surgery*; D021362:Palate, Hard / Q000000981:diagnostic imaging*; D055114:X-Ray Microtomography