Osteodistraction

The placement of dental implants needs an adequate alveolar ridge in width and height, therefore restoration of deficiencies of alveolar bone is necessary. Different types of augmentation bone procedures has been described.

The procedures can be classified between those with autogenous and those with alloplastic materials i.e. hydroxylapatite.The sucessfull osseointegration of dental implants is only possible in vital bone material. Beside the amount of bone also the vitality of the bone very important for the successfull incorporation of implants.This is the reason why implants osseointegration in radiated bone is not so easy to achieve. The autogenous bone augmentation procedures can be calssified basically in free bone transplants and in those with microsurgically bone pocedures. Commonly the free bone grafts are successful for implants augmenation procedures.
Depending on the amount of graft is needed the donor site is choosen. In many patients the bone delivered from iliac crest. Mostly the implants are inserted in a second procedure after healing of the bone transplants. This is almost completed after 4 months of bone transplantation. The most important argument against the bone transpaltantion procedure is the donor site morbidity. The procedure takes longer time; the patient has to stay in the hospital and defects in the donor site are possible. Besides the morbidity for the patient the costs of this procedure are quite high. So another procedures for alveolar ridge augmenation were looked for.

A technique using osteotomy with different type of mobilization is the procedure of ostedistraction. This technique was the first described by Iliazarov for lenthening of the lower limb. McCarthy used this technique for lengthening of the mandible in children with hemifacial microsomia. Block et al (1996), described the augmentation of the deficient alveolar ridge with osseodistraction for implant insertion at the animals.

The advantages of this technique are mobilization of a vascularized bone segment and no need for second procedure harvesting bone transplantations, therefore the morbidity can be reduced. Besides this the recontruction of soft tissue is also possible with the lengthening of the bone. Vertical lengthening of the alveolar process is quite easy possible. But the broadening of the alveolar process is not so easy possible and the distractor advices are not so cheap, those are the disanvantage of this procedure.