前列腺素E2结合Herbst功能矫治器对生长发育晚期比格犬髁突生长影响的锥形束CT分析

A cone-beam CT investigation on condylar growth in beagle dog treated with Herbst appliance and prostaglandin E2 during late stage of growth

目的 应用锥形束CT分析外源性前列腺素E2（prostaglandin E2,PGE2）结合Herbst功能矫治器对生长发育晚期比格犬髁突生长的作用,为PGE2临床应用于生长发育晚期患者的功能矫治提供实验依据.方法 将24只雄性比格犬（8个月龄）,按随机数字表法分为4组（每组6只）：Herbst组和Herbst＋PGE2组安装Herbst功能矫治器;PGE2组和Herbst＋PGE2组双侧颞下颌关节腔内注射0.1 ml PGE2溶液（含PGE20.05 mg）,自然生长组和Herbst组双侧颞下颌关节腔内注射0.1 ml生理盐水,各组均每3天注射1次,注射20次,共60 d.实验前后进行头颅锥形束CT扫描,采用InVivo5软件三维重建,测量颞下颌关节相关测量项目,比较每组实验前后差异以及实验前后变化量的组间差异.结果 Herbst组、PGE2组和Herbst＋PGE2组髁突高度实验前后变化量[分别为（0.19±0.04）、（0.38±0.14）和（0.65±0.08）mm]和髁突前后径实验前后变化量[分别为（0.18±0.30）、（0.51±0.24）和（0.70±0.24）mm]均显著大于自然生长组[（0.01±0.07）和（0.02±0.23）mm]（P〈0.05）;PGE2组和Herbst＋PGE2组髁突高度和髁突前后径的实验前后变化量均显著大于Herbst组（P〈0.05）;Herbst＋PGE2组髁突高度和髁突前后径的实验前后变化量均显著大于PGE2组（P〈0.05）.结论 单纯注射适量外源性PGE2于颞下颌关节腔内与单纯戴用Herbst功能矫治器,均可使生长发育晚期比格犬髁突产生一定量的生长;PGE2与Herbst功能矫治器结合运用可使髁突生长更明显.

Objective To assess the mandibular condylar growth using cone-beam CT （CBCT） in beagle dogs treated with Herbst appliance and exogenous prostaglandin E2 （PGE2） during late stage of growth. Methods Twenty-four male beagle dogs aged 8 months were divided into four groups according to the random number table （n=6 in each group）： natural growth group, mandibular protraction group （Herbst group）, injected prostaglandin E2 group （PGE2 group）, mandibular protraction plus injected prostaglandin E2 group （Herbst＋PGE2 group）. The beagle dogs in Herbst＋PGE2 group and PGE2 group were injected 0.1 ml of prostaglandin E2 （dose of 0.05 mg） into bilateral temporomandibular joint articular cavity. The dogs in natural growth group and Herbst group were injected 0.1 ml of saline into bilateral temporomandibular joint articular cavity as control. PGE2 and saline were injected once every 3 days for 60 days, respectively. CBCT was taken before the application of Herbst appliance and after removal of the appliance for all beagle dogs in four groups at the same time. The CBCT images were reconstructed using Invivo5 software and the relevant parameters of temporomandibular joint were measured. Results No significant difference was found in natural growth group before and after the experiment （P〉0.05）. After the treatment, the condylar height and condylar size in Herbst group （[0.19＋0.04] and [0.18＋0.30] mm）, PGE2 group （[0.38＋0.14] and [0.51＋0.24] mm） and Herbst＋PGE2 group （[0.65＋0.08] and [0.70＋0.24] mm） slightly increased （P〈0.05）. The condylar changes in all experimental groups were greater than the natural growth group （P〈0.05）, and the ranges of change, in descending order, were Herbst＋PGE2 group, PGE2 group and Herbst group （P〈0.05）. However, the condylar longitudinal distances, condyle width, condylar transverse diameter, glenoid fossa width and glenoid fossa depth had no statistically significant difference among the four groups （P〉0.05）. Conclusions Injection of exogenous PGE2 into the temporomandibular joint articular cavity, or using Herbst appliance separately, a certain amount of growth was observed on the mandibular condyle in beagle dogs during late stage of growth. The combination of Herbst appliance and exogenous PGE2 injection made the condylar growth more obviously.