鼻竇補骨手術合併人工植牙治療後移植骨高度變化之回顧分析

Abstract

背景: 上顎後牙區缺牙患者常以植牙的方式重建口腔功能,但是由於上顎後牙區長期缺牙加上 鼻竇腔氣室化的緣故,導致骨量不足,常須合併做鼻竇補骨手術以增加骨量。手術主要是藉 由將鼻竇黏膜往上抬昇得到額外的空間,供人工或者自體移植骨植入,改善骨量不足,以利 進行人工植體之植入手術。文獻上有許多探討上顎後牙區骨量不足接受鼻竇補骨合併人工植 牙手術之成功率的相關研究,但是對於移植骨之長期穩定性、以及其影響因素的研究則較少。 研究目的: 本研究希望透過回顧病患之定期追蹤資料來觀察移植骨長期之穩定性,並且藉此找出影 響穩定性之關鍵因素,以確定治療方法之臨床效益。 研究方法: 本研究收集自 2002 至 2008 年於台大醫院口腔顎面外科門診接受人工植體種植合併鼻竇 補骨手術的病患。病患在植體植入手術後回診追蹤至少兩年以上才列入本研究。共 47 人,60 個上顎竇接受鼻竇補骨手術,以多孔性雙相磷酸鈣(macroporous biphasic calcium phosphate, MBCP)與去礦化冷凍乾燥移植骨(deproteinized freeze dried bone allograft, DFDBA)為補骨 材料,總計有 102 支植體。記錄各項可能影響植體成功率、移植骨穩定性之臨床因子,並藉 由各種影像學分析測量原有鼻竇高度、移植補骨後鼻竇高度,藉此測量移植骨長期之變化, 分三個位置量測,分別為距植體近心 2 mm 處、植體中心處、距植體遠心 2 mm 處;利用回診 時之鼻竇補骨後高度與原有鼻竇高度之比值來分析移植補骨後鼻竇高度經過長時間後與原有 鼻竇高度之關係;並將移植骨與植體根尖部之關係分為三類,第一類是植體根尖部上方仍有 明顯的移植骨存在,植體根尖部低於周圍移植骨高度,第二類是植體根尖部與周圍移植骨高 度相同,第三類是植體根尖部高於周圍移植骨高度;可以用來表示移植骨在長期下來和植體 之間的關係,亦可用來表示移植骨之穩定性。此外,並以統計學分析各項臨床因子與植體成 功率以及移植骨穩定性之關係。

研究結果: 102 支植體,有 2 支植體失敗,植體成功率為 98.03%,並沒有任何臨床因子與植體成功率有統計上之相關。 在移植骨穩定性方面,所有移植體中,自植體植入至回診時之移植骨變化量(graft height changes)在距植體近心 2 mm 處平均為 1.55±2.29 mm(減少 20.02%);植體中心處平均為 1.08±1.50 mm(減少 11.09%);距植體遠心 2 mm 處平均為 1.42±2.27 mm(減少 14.67%)。 DFDBA移植體中,移植體變化量在距植體近心2 mm處平均為3.17±2.50 mm(減少40.25%); 植體中心處平均為 1.52±1.33 mm(減少 14.78%);距植體遠心 2 mm 處平均為 3.21±2.50 mm (減少 35.02%)。MBCP 移植體中,移植骨變化量在距植體近心 2 mm 處平均為 0.84±1.80 mm (減少 10.95%);植體中心處平均為 0.90±1.54 mm(減少 9.54%);距植體遠心 2 mm 處平均 為 0.65±1.67 mm(減少 5.95%)。 回診時之移植補骨後鼻竇高度與原有鼻竇高度之比值(follow-up grafted sinus height / original sinus height, GSH(f/u) ratio),所有移植體中,在距植體近心 2 mm 處為 1.87±4.58; 距植體遠心 2 mm 處為 3.51±3.77,且兩個位置之比值有達到統計上顯著差異,P<0.05。DFDBA 組中,在距植體近心 2 mm 處為 0.66±0.82;距植體遠心 2 mm 處為 3.23±3.14,且兩個位置 之比值有達到統計上顯著差異,P<0.05。MBCP 組中,在距植體近心 2 mm 處為 2.43±5.6; 距植體遠心 2 mm 處為 3.63±4.03,兩個位置之比值並沒有達到統計上顯著差異,P>0.05。 植體根尖部與移植骨之關係(implant apex graft type):所有移植體中,第一類有 73 支 植體(72.2%),第二類有 11 支植體(10.8%),第三類有 17 支植體(16.8%)。DFDBA 組中, 第一類有 15 支植體(50.00%),第二類有 2 支植體(6.67%),第三類有 13 支植體(43.33%)。 MBCP 組中,第一類有 58 支植體(81.69%),第二類有 9 支植體(12.68%),第三類有 4 支 植體(5.63%)。 統計分析與移植骨穩定性相關之臨床因子,結果發現移植骨材料、植體相關位置、術中 鼻竇黏膜穿孔等與移植骨穩定性有關。移植骨穩定性 MBCP 比 DFDBA 明顯較好(P<0.05); 移植骨長期變化量在距植體近心、遠心 2 mm 處明顯多於植體中心處(P<0.05);在術中有鼻 竇黏膜穿孔者明顯多於無鼻竇黏膜穿孔者(P<0.05)。 結論: 鼻竇增高手術目前為一種十分常見之上顎補骨手術,本研究回顧病患之定期追蹤資料來觀察移植骨長期之穩定性及其臨床影響因子,發現移植骨材料、植體相關位置、術中鼻竇黏 膜穿孔等都與移植骨穩定性有統計上的顯著相關。

Background： Dental implant therapy has become a standard rehabilitation method for patients suffered from missing teeth in the posterior maxilla. Because of disuse atrophy and continuous pneumatization of the maxillary sinus, insufficient bone height for dental implantation is common in the posterior maxilla which necessitates sinus augmentation to increase the bone volume. In this surgical technique the Schneiderian membrane is elevated and then bone graft materials are placed into the newly created subantral space to increase bone volume for implant therapy. Previous studies showed that the survival rates for dental implants in combination with sinus augmentation are high. However, the long-term stability of sinus graft and factors influencing graft stability have seldom been examined. Purpose: By examination of the changes in sinus graft volume over a long period and analysis of the relations between graft alteration and various clinical parameters, the long-term efficacy of the sinus augmentation technique is determined. Materials and Methods： Patients who received dental implantation in combination with sinus augmentation at the Department of Oral Maxillofacial Surgery, National Taiwan University Hospital during 2002 to 2008 were included in the study. A total of 47 patients were followed for at least two years. Macroporous biphasic calcium phosphate （MBCP） or deproteinized freeze dried bone allograft （DFDBA） were used as graft materials in 60 maxillary sinus augmentation with total 102 implants. Clinical factors that may influence implant success and graft stability were recorded. Changes in graft height were calculated in three locations, 2 mm mesial to implant, directly above implant, and 2 mm distal to implant. The GSH ratio （follow-up grafted sius height versus original sius height） were calculated as follow-up grafted sinus height versus original sinus height. The relationship between grafted sinus floor and implant was classified into three groups: Group I, in which the grafted sinus floor was above the implant apex; Group II, in which the implant apex was level with the grafted sinus floor; and Group III, in which the grafted sinus floor was below the implant apex. The relations between various clinical parameters and implant success or graft stability were analyzed statistically by Chi Square Test, Student t Test, Logistic Regression Model. Results： There were 2 implants defined as failure, and the overall implant success rate was 98.03%. No clinical factor was significantly related to implant success, all P>0.05. In average, the long term graft change at the site 2 mm mesial to implant was 1.55±2.29 mm （mean±SD）（loss 20.02%）; directly above implant was 1.08±1.50 mm （loss 11.09%）; 2 mm distal to implant was 1.42±2.27 mm （loss 14.67%）. When DFDBA grafts were considered separately, the long term change at the site 2 mm mesial to implant was 3.17±2.50 mm （loss 40.25%）; directly above implant was 1.52±1.33 mm （loss 14.78%）; 2 mm distal to implant was 3.21±2.50 mm （loss 35.02%）. In MBCP group, the long term change at the site 2 mm mesial to implant was 0.84±1.80 mm （loss 10.95%）; directly above implant was 0.90±1.54 mm （loss 9.54%）: 2 mm distal to implant was 0.65±1.67 mm （loss 5.95%）. For all sinus grafts, the mean follow-up GSH ratio 2 mm mesial to implant was 1.87±4.58; 2 mm distal to implant was 3.51±3.77. Loss of graft height at mesial site was smaller than that at the distal, and the difference was significant statistically （P<0.05）. In DFDBA group, the follow-up GSH ratio at the site 2 mm mesial to implant was 0.66±0.82; 2 mm distal to implant was 3.23±3.14. And the difference was significant statistically （P<0.05）. In MBCP group, follow-up GSH ratio at the site 2 mm mesial to implant was 2.43±5.6; 2 mm distal to implant was 3.63±4.03, but the difference was not significant statiscally （P>0.05）. The relations between grafted sinus floor and implant apex were as follows: 73 implants （72.2%） were in group I, 11 implants （10.8%） group II, 17 implants （16.8%） group III. In DFDBA group, 15 implants （50.00%） were in group I, 2 implants （6.67%） group II, 13 implants （43.33%） group III. In MBCP group, 58 implants （81.69%） were in group I, 9 implants （12.68%） group II, 4 implants （5.63%） group III. Concerning the relations between graft stability and various clinical parameters were, we found that: graft materials, implant related location, intraoperative sinus membrane perforation and method of access window protection, were significantly associated with graft stability. The grafts were significantly more stable when MBCP was used comparing to DFDBA （P<0.05）. Graft changes were significantly more obvious mesial to the implants comparing to the distal aspects （P<0.05）. Graft loss was noted if membrane perforation happened during augmentation surgery （P<0.05）. Graft changes were more marked when access windows were protected by collagen membrane comparing to window bone plate replacement （P<0.05）. Conclusions: Sinus augmentation is now a routine bone graft technique for implant therapy. In the retrospective study, we noted that sinus grafts decfeased in size in the long term, although this phenomenon was not related to implant success. We also found that graft material, implant related location, intraoperative sinus membrane perforation were factors associated with long term graft stability.