顎裂を伴う多数歯欠損へのインプラント治療の1 例：既存の顎義歯と磁性アタッチメントを利用した治療

抄録

Widely ranging malformations of lips, alveolar bone or palate may often make it difficult to reconstitute the masticatory function with prostheses, especially with dental implants. However, there have been few reports on the application of dental implants in such cases as alveolar clefts. In this report, two dental implants and magnetic attachments were installed in the maxillary molar region. And the surgery was undertaken without any additional bone graft at the alveolar cleft site since the compromised region was anticipated to rarely host the graft because of less vascularity of the surrounding tissues.
The patient was a 48-year-old woman with an alveolar cleft on the left side and oligodontia of the anterior region of the maxilla. After the maxillary left first and second molars had functioned as abutments of the maxillofacial prosthesis over 30 years, the loss of these teeth caused a significant decrease of denture retention. Although three conus crowns of the telescopic system of the denture still remained in the canine and the premolar regions, severe mobility of all three teeth was found. Most of the initially grafted bone from both sides of the iliac crests had been degraded and its residual bone volume was insufficient for implant placement, especially in the anterior region. Although the additional vascularized bone block was necessary to acquire abundant bone volume to stabilize dental implants in the anterior region, we, followed by the patient's refusal of another graft operation, chose another procedure for inserting two implants in not the anterior but the molar region accompanied by magnetic attachments on them to support and retain the existing denture in spite of the complex form of the cleft jaw. Although recent case reports and systematic reviews described the effect of magnetic attachment for implant-supported overdenture( IOD), most cases demonstrate only mandibular trials or maxillary anterior applications of IOD. In the present case, magnetic attachments were applied at the posterior region of the maxilla, and then contributed to improvement of denture retention, recovery of masticatory performance and the pronunciations and the patient's satisfaction in a 3-year prognosis. Generally, the posterior region is difficult for both the patients and the operators to approach because of the narrowed oral cavity with the post-operative mucosal scar; therefore, the simple shape of the keepers can be more advantageous for the surgical and prosthetic operations and daily self-care than any other types of IOD attachments.
Thus, this clinical example indicated that the magnetic attachments on the posterior implants as an IOD constitution were appropriate to not only restriction of their delivery space and retention acquisition of the denture but also maintaining oral hygiene.