Department of Oral and Maxillofacial Surgery, School of Dentistry, Marmara University, Istanbul, Turkey.
Head Face Med. 2023 Aug 30;19(1):40. doi: 10.1186/s13005-023-00387-w.
A fixed screw-retained full-arch restoration supported by four implants is a popular treatment option for edentulous arches. Optimal alignment of implants is quite challenging in extremely atrophied edentulous cases, and a small amount of deviation is expected during guided surgery. This study aimed to compare implant accuracy among edentulous jaws with various levels of atrophy.
Five separate copies of each Cawood and Howell model (III-V) were produced for the maxilla and mandible. A total of 120 implants (30 models). The implant accuracy was assessed based on angular deviations at the base (angle, 3D offset, distal, vestibular, and apical) and tip (3D offset, distal, vestibular, and apical).
The atrophy level of the jaws had a statistically significant effect on deviation; implants showed greater deviation from the planned location as the atrophy level increased.
Given that implant deviation increased with the degree of atrophy, a greater safety margin from important anatomical structures is recommended when planning implant location for guided surgery in Cawood and Howell V cases.
由四颗种植体支持的固定螺钉固位全颌修复是无牙颌的一种流行治疗选择。在极度萎缩的无牙颌病例中，种植体的最佳对齐非常具有挑战性，并且在引导手术期间预计会有少量偏差。本研究旨在比较不同萎缩程度的无牙颌中的种植体精度。
为上颌和下颌制作了每个 Cawood 和 Howell 模型（III-V）的五个单独副本。共 120 个种植体（30 个模型）。基于基底（角度、3D 偏移、远侧、颊侧和根尖）和尖端（3D 偏移、远侧、颊侧和根尖）的角度偏差来评估种植体精度。
颌骨的萎缩程度对偏差有统计学显著影响；随着萎缩程度的增加，种植体偏离计划位置的程度越大。
鉴于种植体偏差随萎缩程度增加，在为 Cawood 和 Howell V 病例的引导手术规划种植体位置时，建议从重要解剖结构留出更大的安全裕度。
