Hellmann Daniel, Knoch Felix M, Repky Stefan, Kilic Fatih, Lapatki Bernd G, Radeke Johanna
Department of Prosthodontics, University of Würzburg, Pleicherwall 2, 97070, Würzburg, Germany.
Dental Academy for Continuing Professional Development, Karlsruhe, Germany.
Clin Oral Investig. 2024 Dec 14;29(1):16. doi: 10.1007/s00784-024-06101-7.
In orthodontics, accurate registration of jaw relationships is essential for correct diagnosis and treatment planning. Therefore, accuracy of the digital spatial registration of maxillary and mandibular models and - for the first time-the influence of dentition stage and malocclusion type on this procedure were investigated under controlled conditions.
Eight pairs of jaw models, representing different occlusal and developmental statuses (m1-m8), were scanned using two IOS types (PS: Primescan; TR: Trios4). Buccal scans for registering maxillary and mandibular models were repeated (n = 3). Reference scans were obtained using a desktop scanner (RDS; Ceramill Map 600). Arch-specific 3D coordinate systems were used to calculate the linear and angular deviations among different registrations. Trueness of registration by PS and TR was calculated using a statistical mixed-effect model (random-effect: model-type). Precision values of IOS registrations across m1-m8 were characterized as standard deviations (SDs).
As maximum deviations compared to RDS, PS showed caudal translation (0.11 ± 0.02 mm), while TR showed ventral translation (0.08 ± 0.06 mm), of the maxillary relative to the mandibular model. Maximum rotational values were calculated for tilting around the transverse axis (PS: anteinclination (0.25 ± 0.16°), TR: retroinclination (0.27 ± 0.16°)). These deviations varied with the malocclusion type. The lowest IOS precision was recorded for sagittal translation (PS: 0.013 ± 0.005 mm, TR: 0.021 ± 0.010 mm) and rotation around the transverse axis (PS: 0.051 ± 0.013°, TR: 0.076 ± 0.031°).
Registrations using buccal IOS scans showed quantifiable but clinically negligible 3D deviations from reference scan registrations, whereby the type of tooth and jaw misalignment did not appear to have a clinically relevant influence. Therefore, the examined IOSs appear to be suitable for digital jaw relation determination in everyday clinical orthodontic practice.
在正畸学中，准确记录颌骨关系对于正确诊断和治疗计划至关重要。因此，在可控条件下研究了上颌和下颌模型数字空间配准的准确性，以及首次研究了牙列阶段和错牙合类型对该过程的影响。
使用两种口腔内扫描仪（PS：Primescan；TR：Trios4）扫描八对代表不同咬合和发育状态（m1 - m8）的颌骨模型。重复进行用于配准上颌和下颌模型的颊侧扫描（n = 3）。使用台式扫描仪（RDS；Ceramill Map 600）获取参考扫描。使用特定牙弓的三维坐标系计算不同配准之间的线性和角度偏差。使用统计混合效应模型（随机效应：模型类型）计算PS和TR配准的准确性。将IOS在m1 - m8上的配准精度值表征为标准差（SD）。
与RDS相比，最大偏差方面，PS显示上颌相对于下颌模型有尾侧平移（0.11±0.02毫米），而TR显示腹侧平移（0.08±0.06毫米）。计算出围绕横轴倾斜的最大旋转值（PS：前倾（0.25±0.16°），TR：后倾（0.27±0.16°））。这些偏差因错牙合类型而异。矢状向平移（PS：0.013±0.005毫米，TR：0.021±0.010毫米）和围绕横轴旋转（PS：0.051±0.013°，TR：0.076±0.031°）的IOS精度最低。
使用颊侧IOS扫描进行的配准显示，与参考扫描配准相比，存在可量化但临床上可忽略不计的三维偏差，牙齿和颌骨错位类型似乎没有临床相关影响。因此，所检测的IOS似乎适用于日常临床正畸实践中的数字颌骨关系确定。
