牙列重度磨耗患者咬合重建前、后颞下颌关节的线性测量

目的:对牙列重度磨耗患者垂直距离进行恢复后,研究颞下颌关节间隙与垂直距离增高之间的相关性,探讨恢复髁突位置对咬合重建的影响。方法:纳入30例牙列重度磨耗行咬合重建的患者,在恢复垂直高度前后,对其双侧的颞下颌关节进行锥形束CT(cone-beam CT,CBCT)扫描,测量颞下颌关节前、上、后间隙大小,分析髁突位置;比较垂直距离恢复前、后的关节间隙等指标,分析患者恢复垂直距离前、后髁突位置的变化。采用SPSS 19.0软件包对颞下颌关节前、上、后间隙进行统计学分析。结果:30例牙列重度磨耗患者颞下颌关节各间隙两侧之间差异无统计学意义(P>0.05),故将两侧颞下颌关节间隙合并统计。治疗前关节前、上、后间隙分别为(2.01±0.52)mm、(3.15±0.94)mm、(2.70±0.98)mm;治疗后关节前、上、后间隙分别为(2.03±0.35)mm、(3.46±0.74)mm、(2.79±0.58)mm。通过计算In(P/A)值和线性比率(linear ratio,LR)得出重度磨耗患者治疗前52%髁突前移位;咬合重建治疗后,治疗前髁突前移位的患者复位率达86.7%。结论:重度磨耗患者除了恢复其垂直距离外,还应诱导髁突回到正常位置,避免产生关节症状。

Evaluation of occlusal reconstruction and cone-beam CT measurement of temporomandibular joint in patients with severe tooth wear

PURPOSE: To explore the correlation between increased vertical dimensions and temporomandibular joint (TMJ) spaces of patients with severe tooth wear after occlusal reconstruction treatment. Methods: The TMJ spaces and the condylar positions of 30 patients were measured by cone-beam CT (CBCT) before and after treatment. SPSS 19.0 software package was used to analyze the anterior, superior and posterior space of TMJ. Independent sample t test was utilized to evaluate the correlation between vertical dimension and TMJ spaces. Results: There was no significant difference between TMJ spaces of two sides, the data of two sides were combined for further analysis. The mean anterior interspace, superior interspace, posterior interspace was (2.01± 0.52)mm, (3.15± 0.94)mm, (2.70± 0.98)mm before treatment, and (2.03± 0.35)mm, (3.46± 0.74)mm, (2.79± 0.58)mm after treatment, respectively. Based on calculating the In(P/A) and linear ratio(LR), condylar position moved backward for 52% patients before treatment. After occlusal reconstruction, the reduction rate of anterior displacement of condyle was 86.7%. Conclusions: In addition to restoring its vertical dimensions of patients with severe tooth wear, the condyle should be induced to appropriate position to prevent TMJ symptoms.