Londono Jimmy, Schoenbaum Todd R, Varilla Ortiz Alma Veronica, Franco-Romero Guillermo, Villalobos Vanessa, Carosi Paolo, Mijiritsky Eitan, Pozzi Alessandro
Ronald Goldstein Center for Esthetic and Implant Dentistry, Department of Restorative Sciences, Dental College of Georgia, Augusta, GA 30912, USA.
Department of Restorative Sciences, Dental College of Georgia, Augusta, GA 30912, USA.
J Clin Med. 2023 Jun 20;12(12):4149. doi: 10.3390/jcm12124149.
The aim of this study was to assess intra-arch mandibular dimensional changes that may occur during mouth opening using cone beam-computed tomography (CBCT). Fifteen patients in need of any type of treatment whose execution considered a pre- and post-CBCT assessment consented and were enrolled. CBCTs were taken with the following settings: 90 kV, 8 mA, field of view (FOV) 140 by 100 mm (height and diameter), Voxel size 0.25 mm (high resolution). The pre-CBCT was executed in the maximum mandibular opening (MO), while the post-CBCT was in the maximum intercuspation (MI). A thermoplastic stent with radiopaque fiducial markers (steel ball bearings) was fabricated for each patient. Measurements were made using radiographic markers between contralateral canines and contralateral first molars and between ipsilateral canines and first molars on both sides. Paired -tests were performed to evaluate the difference between open and closed positions on these four measurements. In the MO position were registered a significative tightening of the mandible at the canine (-0.49 mm, SD 0.54 mm; < 0.001) and molar points (-0.81 mm, SD 0.63 mm; < 0.001) and a significative shortening of the mandible on the right (-0.84 mm, SD 0.80 mm; < 0.001) and left sides (-0.87 mm, SD 0.49 mm; < 0.001). Within the study limitations, mandibular flexure determined a significant shortening and tightening between maximum intercuspation to maximum opening positions. Mandibular dimensional changes should be considered in light of other patient factors in the treatment planning of implant positioning and long-span complete arch implant-supported fixed prostheses in order to avoid technical complications.
本研究的目的是使用锥形束计算机断层扫描（CBCT）评估张口过程中可能发生的牙弓内下颌骨尺寸变化。15名需要进行任何类型治疗且其治疗方案需要CBCT术前和术后评估的患者同意并参与了研究。CBCT扫描设置如下：90 kV，8 mA，视野（FOV）140×100 mm（高和直径），体素大小0.25 mm（高分辨率）。术前CBCT在最大下颌开口（MO）时进行，术后CBCT在最大牙尖交错位（MI）时进行。为每位患者制作了带有不透射线基准标记（钢珠）的热塑性支架。使用射线照相标记在双侧对侧尖牙与对侧第一磨牙之间以及同侧尖牙与第一磨牙之间进行测量。进行配对t检验以评估这四项测量中开口位与闭口位之间的差异。在MO位时，下颌骨在尖牙处（-0.49 mm，标准差0.54 mm；P<0.001）和磨牙处（-0.81 mm，标准差0.63 mm；P<0.001）有明显收紧，右侧（-0.84 mm，标准差0.80 mm；P<0.001）和左侧（-0.87 mm，标准差0.49 mm；P<0.001）下颌骨有明显缩短。在本研究的局限性范围内，下颌骨弯曲导致从最大牙尖交错位到最大开口位之间有明显缩短和收紧。在种植体定位和长跨度全牙弓种植体支持的固定修复体的治疗计划中，应结合其他患者因素考虑下颌骨尺寸变化，以避免技术并发症。
