Reconstruction of the Atrophic Edentulous Maxilla with Free Iliac Crest Grafts and Implants: A 3‐Year Report of a Prospective Clinical Study

Abstract

Purpose: The purpose of this study was to perform a longitudinal follow-up study of implant stability in grafted maxillae with the aid of clinical, radiological, and resonance frequency analysis (RFA) parameters. Materials and Methods:The atrophic edentulous maxillae in 29 patients were reconstructed with free iliac crest grafts using onlay/inlay or interpositional grafting techniques. The endpoint of the resorption pattern in the maxilla determined the grafting technique used. Endosteal implants were placed after 6 months of bone-graft healing. Implant stability was measured four times using RFA: when the implants were placed, after 6 to 8 months of healing, after 6 months and 3 years of bridge loading. Individual checkups were performed at the two later RFA registrations after removal of the supraconstructions (Procera® Implant Bridge, Nobel Biocare AB, Göteborg, Sweden). Radiological follow up of marginal bone level was performed annually.Results: Twenty-five patients remained for the follow-up period. A total of 192 implants were placed and with a survival rate of 90% at the 3-year follow up. Women and an implant position with a class 6 resorption prior to reconstruction were factors with significant increased risk for implant failure (multivariate logistic regression). Twelve of the 20 failed implants were lost before loading (early failures). The change in the marginal bone level was 0.3 ± 0.3 mm between baseline (bridge delivery) and the 3-year follow up. The implant stability quotient (ISQ) value for all implants differed significantly between abutment connection (60.2 ± 7.3) and after 6 months of bridge loading (62.5 ± 5.5) (Wilcoxon signed ranks test for paired data, p = .05) but were nonsignificant between 6 months of bridge loading and 3 years of bridge loading (61.8 ± 5.5). There was a significant difference between successful and failed implants when the ISQ values were compared for individual implants at placement (Mann-Whitney U test, p = .004). All 25 patients were provided with fixed implant bridges at the time of the 3-year follow up. Conclusion:This clinical follow up using radiological examinations and RFA measurements indicates a predictable and stable long-term result for patients with atrophic edentulous maxillae reconstructed with autogenous bone and with delayed placement of endosteal implants. The ISQ value at the time of placement can probably serve as an indicator of level of risk for implant failure.KEY WORDS: autogenous bone graft, edentulous atrophic maxilla, endosteal implants, implant survival, marginal bone level, resonance frequency analysis 46 T he secondary effects of tooth loss are alveolar bone resorption. The loss of alveolar bone compromises soft tissue support and the lower anterior facial height.

Otojen iliak kemikle greftlenen atrofik maksillanın 4 implant üstü zirkonyum sabit protezle rekonstrüksiyonu: Olgu sunumu

“…3 İleri derecede rezorpsiyonun olduğu ve bol miktarda greft gereken maksiller kemik augmentasyonlarında genel greft donör saha olarak anterior iliak krest oldukça güvenlidir. 9 İliak krestin donör bölge olarak birçok avantajı olmasına rağmen greft alım işlemi sırasında ve sonrasında bölgede birçok komplikasyonun oluşma riski vardır.…”

“…Bu yöntemlerde kullanılan ekstraoral donör sahaları; kalvarial kemik, kostalar ve iliak kemik iken, intraoral olarak ramus, simfiz ve tüber sahaları greft alınabilecek verici alanlar olarak sayılabilir. 3 Yetersizliğin az olduğu alanlarda intraoral sahalar tercih edilirken, kemik ihtiyacı fazla olduğunda ekstraoral alanlar tercih edilir. Bunlardan iliak kemikten alınan otojen kemik, sahip olduğu osteoündiksiyon, osteokondüksiyon ve osteojenik potansiyeliyle gerekli olan kemik remodelasyonunu sağlar.…”

Surgical techniques for maxillary bone grafting - literature review

“…Due to its endochondral origin, this type of bone graft is resorbed more rapidly than the intramembranous grafts. In these cases, the maxillofacial team works closely with the orthopedic team, which is responsible for removal of the iliac crest bone graft 10,12,13 . The surgical intervention should be performed in a hospital under general anesthesia.…”

“…Generally, the complications are related to the amount of bone removed, and internal bleeding being may occur, with extensive areas of hematoma and edema, pain, penetration of abdomen and viscera injuries area, and rupture of the lateral femoral cutaneous nerve, which causes partial or permanent paresthesia of the lateral portion of the thigh and difficulty in walking 12,13 .…”

Mandibular bone regeneration after bone slat technique

“…A number of surgical procedures have been utilized to reconstruct the alveolar crest. These procedures include "split-ridge" (osteotomy for lateral expansion), osteodistraction, bone grafting with various grafting materials (autogenous bone, allograft, xenograft and alloplastic materials), guided bone regeneration (GBR) alone or in combination with grafting materials and other techniques (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). Therefore, the purpose of the present study was to clinically and cone beam computerized tomography (CBCT) evaluate the quantity and quality of newly regenerated bone for mandibular posterior lateral defect utilizing autogenous cortical as a membrane with autogenous particulate bone to facilitate placement of implants.…”