Bell R Bryan, Blakey George H, White Raymond P, Hillebrand Dennis G, Molina Anthony
Received from the School of Dentistry, The University of North Carolina at Chapel Hill, 27599, USA.
J Oral Maxillofac Surg. 2002 Oct;60(10):1135-41. doi: 10.1053/joms.2002.34986.
Vastly different surgical techniques have been advocated for osseous reconstruction of the severely atrophic mandible. Endosseous implants placed in autologous bone grafts have been proposed to minimize graft resorption and restore function; however, sufficient bone must exist to support the implants and prevent pathologic fracture. The purpose of this retrospective analysis was to assess the efficacy of autologous bone grafting and the subsequent placement of endosteal implants as a staged procedure in patients with severely atrophic mandibles.
The records of all patients presenting to The University of North Carolina for treatment from 1997 to 1999 with atrophic mandibles (vertical mandibular height <7 mm as measured on panoramic radiographs in at least 1 site at the mandibular midline and at the thinnest portion of the mandibular body) were reviewed. Bone height was assessed preoperatively, immediately postoperatively, at the time of implant placement (4 to 6 months), and again at 12 and 24 months after bone grafting from posterior iliac crest to the mandible via an extraoral approach. Five endosteal implants were subsequently placed in each patient as a delayed procedure 4 to 6 months after bone grafting, and prosthetic rehabilitation was completed with implant supported prostheses.
Fourteen consecutive patients were identified with a median preoperative bone height of 9 mm (interquartile range, 25th to 75th percentile [IQ], 7 to 10 mm) in the mandibular midline and 5 mm (IQ, 2 to 5 mm) in the body region. There were no perioperative complications. Median estimated blood loss during the bone graft procedure, as estimated by the surgeon and the anesthesiologist, was 300 mL (IQ, 150 to 1,100 mL), and 1 patient required blood transfusion secondary to symptomatic anemia. The mean loss of vertical bone height after grafting and during the 4 to 6 months before implant placement was 33%. After implant placement and at 12 months, the vertical bone loss was negligible in the implant-supported region and less than 11% in the body region.
Reconstruction of the severely atrophic mandible using autogenous corticocancellous bone grafts followed by placement of osseointegrated implants in 4 to 6 months can restore and maintain mandibular bone sufficient to support implants and facilitate successful restoration of occlusion. A prospective study is planned to identify predictors of successful outcomes compared with other surgical/prosthetic treatment.
对于严重萎缩性下颌骨的骨重建，人们提倡采用截然不同的手术技术。有人提出将骨内种植体植入自体骨移植块中，以尽量减少移植骨吸收并恢复功能；然而，必须有足够的骨来支撑种植体并防止病理性骨折。本回顾性分析的目的是评估自体骨移植以及随后分阶段植入骨内种植体治疗严重萎缩性下颌骨患者的疗效。
回顾了1997年至1999年在北卡罗来纳大学就诊的所有萎缩性下颌骨患者（全景X线片显示下颌骨中线至少1个部位以及下颌体最薄处垂直下颌高度<7mm）的记录。在术前、术后即刻、种植体植入时（4至6个月）以及从髂后嵴经口外途径将骨移植到下颌骨后12个月和24个月时评估骨高度。随后在骨移植后4至6个月为每位患者延迟植入5枚骨内种植体，并使用种植体支持的修复体完成修复重建。
确定了14例连续患者，下颌骨中线术前骨高度中位数为9mm（四分位间距，第25至75百分位数[IQ]，7至10mm），下颌体区域为5mm（IQ，2至5mm）。无围手术期并发症。外科医生和麻醉医生估计的骨移植手术期间估计失血量中位数为300mL（IQ，150至1100mL），1例患者因症状性贫血需要输血。移植后以及种植体植入前4至6个月期间垂直骨高度的平均丢失率为33%。种植体植入后及12个月时，种植体支持区域的垂直骨丢失可忽略不计，下颌体区域小于11%。
采用自体皮质松质骨移植重建严重萎缩性下颌骨，随后在4至6个月内植入骨整合种植体，可恢复并维持足以支撑种植体的下颌骨，促进咬合的成功恢复。计划进行一项前瞻性研究，以确定与其他手术/修复治疗相比成功结果的预测因素。
