State Key Laboratory of Oral Diseases & National Clinical Research Centre for Oral Diseases, West China Hospital of Stomatology, Sichuan University, 14 Ren Min Nan Road, Chengdu, 610041, China.
Department of Oral and Maxillofacial Surgery, West China Hospital of Stomatology, Chengdu, 610041, China.
Sci Rep. 2019 Mar 12;9(1):4261. doi: 10.1038/s41598-019-40478-w.
The symmetrically stable craniofacial bony structure supports the complex functions and delicate contour of the face. Congenital craniofacial deformities are often accompanied by bony defects and have been repetitively correlated with compromised dento-maxillary stability, but neither the extent nor the pattern of cleft-related maxillary instability has been explored in detail. Furthermore, it is largely unknown if the bony defect and related instability are correlated with secondary maxillary deformity common among patients with orofacial clefts. With the aid of finite element modeling, we studied the detailed relationship between cleft-related bony defect and maxillary stability under occlusal loading. Craniofacial models were generated based on cone-beam computed tomography data and loaded with mimicked bite forces along the axial axis of each tooth. Our data showed that all cleft models exhibited more asymmetrical deformations under mastication compared with the normal. Models with palatal cleft demonstrated greater asymmetry, greater dental arch contraction, and less maxillary protrusion compared to models with alveolar cleft only. For unilateral cleft models, alveolus on non-cleft side tended to be more protruded and lifted than the cleft side. For bilateral cleft models, the most prominent feature was the seriously contracted alveolar arch and curved and pitched premaxillae. These findings indicated cleft type-specific pattern of maxillary instability, which were largely in accordance with dentoalveolar morphological features among patients. Collectively, our study elucidated the detailed relationship between cleft bony defect and the pattern of maxillary instability, and suggested a prototype for studying the abnormal maxillary and dental arch growth among patients with craniofacial deformities.
对称稳定的颅面骨结构支撑着面部复杂的功能和精细的轮廓。先天性颅面畸形常伴有骨缺陷，并与牙颌面稳定性受损密切相关，但尚未详细探讨过裂隙相关上颌骨不稳定的程度和模式。此外，在很大程度上尚不清楚骨缺陷和相关不稳定是否与口腔裂隙患者中常见的继发性上颌骨畸形有关。借助有限元建模，我们研究了在咬合加载下裂隙相关骨缺陷与上颌稳定性之间的详细关系。基于锥形束 CT 数据生成颅面模型，并沿每个牙齿的轴向轴模拟加载咀嚼力。我们的数据表明，与正常模型相比，所有裂隙模型在咀嚼时表现出更大的不对称变形。与仅牙槽裂模型相比，腭裂模型的不对称性更大，牙弓收缩更大，上颌前突更小。对于单侧裂隙模型，非裂隙侧的牙槽倾向于比裂隙侧更突出和抬起。对于双侧裂隙模型，最突出的特征是牙槽弓严重收缩，以及前颌骨弯曲和倾斜。这些发现表明了上颌骨不稳定的裂隙类型特异性模式，这在很大程度上与患者的牙牙槽形态特征一致。总之，我们的研究阐明了裂隙骨缺陷与上颌骨不稳定模式之间的详细关系，并为研究颅面畸形患者上颌骨和牙弓异常生长提供了一个原型。
