Department of Orthodontics, University of Geneva, Geneva, Switzerland.
Mun-H-Center National Orofacial Resource Center for Rare Diseases, Public Dental Service in Västra Götaland, Gothenburg.
Eur J Orthod. 2021 Oct 4;43(5):527-533. doi: 10.1093/ejo/cjaa068.
BACKGROUND/OBJECTIVES: This research aimed to study the malocclusions of children and adolescents with myotonic dystrophy type 1 (DM1), in respect to healthy individuals, and trace the occlusal changes that occurred in these individuals during growth.
MATERIALS/METHODS: Thirty-six dental casts, from children and adolescents with DM1 living in western and southern Sweden, were compared with a control group of 50 healthy individuals. To identify potential changes in occlusal traits, 26 casts were assessed and followed-up over a median time of 9 years. Independent samples t-tests were used to compare the two groups and their changes over time. Paired samples t-tests tested changes over time within each group (P < 0.05).
DM1 patients had a higher prevalence of anterior open bite, posterior crossbite, and Class III malocclusions. When compared to controls, patients presented smaller upper and lower intermolar as well as intercanine widths. In both groups, the individuals revealed longitudinal changes with a decrease in both upper and lower arch lengths and an increase on the palatal vault height. During the follow-up period, the prevalence of malocclusions remained almost the same, only significantly differing regarding the changes that occurred between groups referred to the upper intermolar width, which decreased among DM1 patients.
CONCLUSIONS/IMPLICATIONS: In comparison to healthy controls, children and adolescents with DM1 have shown already at an early age a higher prevalence of both anterior open bite and posterior crossbite. These occlusal traits did not change with time apart from the upper narrow intermolar width, which further decreased with time.
背景/目的：本研究旨在研究 1 型肌强直性营养不良（DM1）患儿和青少年的错颌畸形，与健康个体进行比较，并追踪这些个体在生长过程中发生的咬合变化。
材料/方法：来自瑞典西部和南部的 36 名 DM1 患儿和青少年的牙模与对照组 50 名健康个体进行了比较。为了确定咬合特征的潜在变化，对 26 个牙模进行了评估，并在中位数为 9 年的时间内进行了随访。采用独立样本 t 检验比较两组及其随时间的变化。配对样本 t 检验测试了每组内随时间的变化（P<0.05）。
DM1 患者的前牙开颌、后牙反颌和 III 类错颌的患病率较高。与对照组相比，患者的上下颌间距和上下颌间宽度较小。在两组中，个体都呈现出纵向变化，上、下颌弓长度减少，腭穹窿高度增加。在随访期间，错颌的患病率几乎保持不变，仅在 DM1 患者的上颌间距的组间变化方面存在显著差异，该距离在 DM1 患者中减小。
结论/意义：与健康对照组相比，DM1 患儿和青少年在早期就表现出更高的前牙开颌和后牙反颌的患病率。这些咬合特征除了上颌间距变窄且随时间进一步减小外，随时间没有变化。
