Department of Pediatric Dentistry, West China Hospital of Stomatology, Sichuan University & State Key Laboratory of Oral Diseases & National Clinical Research Center for Oral Diseases, Chengdu, China.
Int J Paediatr Dent. 2022 Nov;32(6):915-924. doi: 10.1111/ipd.12970. Epub 2022 May 18.
Placing preformed metal crowns (PMCs) on all eight primary molars at one single clinical visit may disrupt a child's occlusion; the literature regarding the effects on occlusion and temporomandibular joint (TMJ) is scarce.
This study aimed to quantify the changes in occlusion using T-Scan III and to investigate whether there was TMJ dysfunction after placing eight PMCs at the same time.
In this study, we enrolled children with severe early childhood caries (S-ECC) and dental phobia, who needed eight PMCs to be placed under general anesthesia. The participants underwent occlusal examinations with a computed occlusal analysis system. The vertical dimension of occlusion (VDO) was measured using a dental vertical dimension gauge, TMJ dysfunction signs were recorded by the clinical dysfunction index (Di), and TMJ dysfunction symptoms were recorded using a questionnaire. The data were collected before treatment (T ), 1 week after treatment (T ), and 1 month (T ) and 3 months (T ) after treatment during follow-up visits. Repeated-measures analysis of variance and Friedman's test were used for occlusal data analysis. In addition, the Di and symptoms were compared over time using McNemar's test.
Forty patients (mean age = 4.25 ± 0.63 years, age range = 3-5 years, 21 boys and 19 girls) were followed up for 3 months. The occlusal contact area 3 months after treatment did not return to the pretreatment status (p = .03). The total of force at the 3-month follow-up visit increased significantly (p = .009) compared with that at the pretreatment. The asymmetric ratio of occlusal force at the 1-month follow-up visit was restored to pretreatment. Concerning the occlusion time, no significant changes were observed for any time intervals (p = .069). The VDO was recovered at the 1-month follow-up visit. The statistical analysis of TMJ dysfunction showed no significant differences in the Di and TMJ dysfunction symptoms before and after treatment (p > .05).
After undergoing eight PMC restorations under general anesthesia, occlusal re-equilibration was attained approximately after 1 month. There were no significant signs and symptoms of TMJ dysfunction after treatment.
在一次临床就诊中为所有八颗乳磨牙放置预成型金属冠（PMC）可能会破坏儿童的咬合；关于咬合和颞下颌关节（TMJ）影响的文献很少。
本研究旨在使用 T-Scan III 量化咬合变化，并研究同时放置八颗 PMC 是否会导致 TMJ 功能障碍。
本研究纳入了患有严重幼儿期龋（S-ECC）和牙科恐惧症的儿童，他们需要在全身麻醉下放置八颗 PMC。参与者接受计算机咬合分析系统的咬合检查。使用牙科垂直距离计测量垂直咬合距离（VDO），通过临床功能障碍指数（Di）记录 TMJ 功能障碍迹象，通过问卷记录 TMJ 功能障碍症状。在治疗前（T0）、治疗后 1 周（T1）、治疗后 1 个月（T2）和 3 个月（T3）的随访期间收集数据。使用重复测量方差分析和 Friedman 检验进行咬合数据分析。此外，使用 McNemar 检验比较 Di 和症状随时间的变化。
40 名患者（平均年龄 4.25 ± 0.63 岁，年龄范围 3-5 岁，21 名男孩和 19 名女孩）随访 3 个月。治疗后 3 个月的咬合接触面积未恢复到治疗前状态（p=0.03）。治疗后 3 个月的总受力明显增加（p=0.009）。治疗后 1 个月的咬合力不对称比恢复到治疗前水平。关于咬合时间，任何时间间隔都没有观察到明显变化（p=0.069）。VDO 在 1 个月的随访中得到恢复。TMJ 功能障碍的统计分析显示，治疗前后 Di 和 TMJ 功能障碍症状无显著差异（p>0.05）。
全身麻醉下进行八颗 PMC 修复后，大约在 1 个月后达到咬合再平衡。治疗后无明显 TMJ 功能障碍迹象和症状。
