The effects of age and sex on mandibular bone graft donor sites

Objectives Intra‐oral bone grafting relies on three‐dimensional understanding of mandibular anatomy. This study assessed the bone volume at the two most common intra‐oral bone harvesting sites, the retromandibular and symphyseal regions, and assessed the impact of age and sex on the available bone at these sites. Materials and methods Demographic and anatomical data were collected from cone beam computer tomographs (CBCT’s) of 200 randomly selected, fully dentate participants (100 male/100 female) between the ages of 24 and 86 years. Statistical analysis was conducted with SPSS V25, using ANalysis of COVAriance (ANCOVA) to determine the effects of age and sex on the measurements at the donor sites. Results At retromandibular sites, women have a broader alveolar crest with a narrower mandible at the level of the IDC. There is a statistically significant difference, between the sexes, in bone width from the buccal cortex to the IDC. Men have a significantly greater distance from the outer buccal plate to the IDC. There is no difference in any measured dimension at the symphyseal region. There is a statistically significant reduction in bone volume with increasing age at both mandibular sites of 0.03–0.05 mm annually, irrespective of tooth loss. Conclusion Anatomical variability due to sex and bone reduction with age are both important findings in dental implantology, which must be considered when treatment planning and selecting bone grafting sites in the mandible. This study reinforces the importance of pre‐operative CBCT in planning bone grafting procedures.