Cottrell D A, Wolford L M
Oral and Maxillofacial Surgery, Boston University School of Graduate Dentistry, MA, USA.
J Oral Maxillofac Surg. 1998 Aug;56(8):935-41; discussion 941-2. doi: 10.1016/s0278-2391(98)90654-1.
This prospective study was designed to evaluate the long-term clinical and radiographic results of porous block hydroxyapatite (PBHA) used as a synthetic bone graft in orthognathic surgery and craniofacial augmentation.
A total of 245 consecutive patients were treated initially. Inclusion criteria for this study included a minimum clinical and radiographic follow-up of 5 years. In addition, all patients with known implant failures were included regardless of whether they met the study criteria. There were 111 patients that met the criteria for inclusion in this study. All patients had undergone orthognathic surgery with rigid fixation and had had inlay or onlay PBHA implants placed. Ninety-six percent of the implants were placed through an intraoral approach. Long-term postoperative radiographs were visually compared with immediate postoperative radiographs for implant position, stability, resorption, and other significant radiographic changes. The clinical examination evaluated for signs and symptoms of infection, wound dehiscence, implant exposure, implant displacement, changes in the overlying mucosa, and development of oronasal or oroantral fistulae.
Four hundred seventy-one implants were placed: 403 in the maxilla, 44 in the mandible, and 24 in the periorbital region. There were 289 implants placed in direct communication with the maxillary sinus. The average follow-up time was 7.2 years (range, 5.0 to 10.3 years). Twenty-three implants (4.9%) were removed during the evaluation period. Lateral maxillary wall grafting had 95.7% success, with nine implants being lost in three patients. One chin implant was removed because of dissatisfaction with the aesthetics. Seven (14%) midpalatal implants used for maxillary expansion were lost, primarily because of exposure of the implant to the oral or nasal cavity at the time of surgery. When PBHA was used for alveolar cleft grafting, there was a 100% failure rate.
The use of PBHA as a bone graft substitute in orthognathic surgery and for facial augmentation showed a high percentage of success and efficacy. However, adequate soft tissue coverage in the nasal floor and on the palate are paramount for success of midpalatal implants. PBHA should not be used for alveolar cleft grafting. Rigid fixation for inlay implants in the maxilla is important to provide stress shielding of the material and minimize micromovement during the initial healing phase.
本前瞻性研究旨在评估多孔块状羟基磷灰石（PBHA）作为正颌外科手术和颅面增大术中合成骨移植材料的长期临床和影像学结果。
最初共治疗了245例连续患者。本研究的纳入标准包括至少5年的临床和影像学随访。此外，所有已知种植体失败的患者均被纳入，无论他们是否符合研究标准。有111例患者符合本研究的纳入标准。所有患者均接受了坚固内固定的正颌外科手术，并植入了嵌体或覆盖式PBHA种植体。96%的种植体通过口内途径植入。将术后长期影像学检查结果与术后即刻影像学检查结果进行直观比较，以评估种植体的位置、稳定性、吸收情况及其他显著的影像学变化。临床检查评估感染、伤口裂开、种植体暴露、种植体移位、覆盖黏膜变化以及口鼻或口窦瘘的发生情况等体征和症状。
共植入471枚种植体：上颌403枚，下颌44枚，眶周区域24枚。有289枚种植体与上颌窦直接相通。平均随访时间为7.2年（范围5.0至10.3年）。在评估期间，23枚种植体（4.9%）被取出。上颌侧壁植骨成功率为95.7%，3例患者中有9枚种植体丢失。1枚颏部种植体因美学效果不佳被取出。用于上颌扩弓的7枚（14%）腭中缝种植体丢失，主要原因是手术时种植体暴露于口腔或鼻腔。当PBHA用于牙槽嵴裂植骨时，失败率为100%。
PBHA作为正颌外科手术和面部增大术中的骨移植替代材料显示出较高的成功率和有效性。然而，腭中缝种植体成功的关键在于鼻底和腭部有足够的软组织覆盖。PBHA不应用于牙槽嵴裂植骨。上颌嵌体种植体的坚固内固定对于提供材料的应力屏蔽以及在初始愈合阶段最小化微动很重要。
