The effects of age, jaw site, and bone condition on oral implant outcomes.

PURPOSE: This paper reviews literature on age and jaw site in relation to jawbone quantity and quality and the osseointegration of endosseous oral implants. RESULTS AND DISCUSSION: The condition of jawbone is both age- and site-specific. However, increased age does not appear to affect the clinical potential for osseointegration or the rate of crestal bone resorption observed around oral implants. In contrast, jaw site is related significantly to osseointegration potential; mandibular sites tend to be more successful than maxillary sites. The reason for this may be that jawbone quality and quantity are often more compromised in maxillary than in mandibular sites. However, evaluation of this relationship has been hampered by a lack of evidence to support the validity and reliability of methods used to assess jawbone condition preoperatively. Furthermore, short-term evidence suggests that high rates of implant success can be achieved in maxillary sites, even those with low trabecular density, if an adequate volume of bone exists to accommodate the implants. Although the rate of crestal bone resorption around oral implants is usually low and may not be site-specific, there is some evidence that it may be greater in sites with less preoperative resorption associated with shorter periods of edentulism. This pattern of bone loss could jeopardize long-term implant outcomes especially in younger implant patients. Another concern in young growing patients is that their prosthetic outcome may become compromised because osseointegrated implants cannot keep pace with growth and development in surrounding structures.
CONCLUSION: To improve our understanding of how the age- and site-specificity of jawbone condition affects oral implant outcomes, research needs to be aimed at establishing reliable and valid measures of preoperative jawbone condition, and at better documenting the effects of jawbone condition on oral implant outcomes.