Abstract
Conventional implants are not suitable for the mandible which was reconstructed with apatite block, because it reduces blood circulation. It was previously confirmed in an experimental study that implant with iliac bone was effective even in the mandible under a poor condition. An irradiated mandible is also unfavorable for implantation due to the same reason. According to our experimental results, it was suggested that implant with iliac bone could be applicable for irradiated mandible. We modified the method of implant with iliac bone which we confirmed in a previous experimental study.
A 63-year-old man with tongue carcinoma underwent the first clinical transplantation of implant with iliac bone. He had received 70 Gy of interstitial irradiation therapy, 90 Gy of external irradiation therapy, chemotherapy and partial glossectomy with radical neck dissection.
Six apatite implants (4 mm in diameter, 9 mm in length) were inserted into the right iliac bone. After 6 months,4 implants were removed with a modified trephine bur and were immediately transplanted into the irradiated mandible. The time interval between irradiation therapy and transplantation was 32 months. Three months later, abutments were connected to each implant, and finally bone-anchored full bridge prosthesis was set. After the transplantation, there was no evidence of active symptom of inflammation after an elapse of 30 months.
The results were as follows:
1. The improvements of this method were designing of trephine bur and guide, bone thickness of the implant with iliac bone and the method of cutting between bottom layer of implants and ilium.It was easy to prepare the implant with iliac bone in consequence.
2. Conventional implants were distinctly contraindicated in high dose irradiated mandible. However it was confirmed that this method of implant with iliac bone could be applied safely to these severe cases.
3. It was suggested that indications of this method were not only the poor quality of bone, but also the small quantity of bone.