Nasiopoulos Athanasios T, Athanasiou Athanasios E, Papadopoulos Moschos A, Kolokithas George, Ioannidou Ioulia
Department of Orthodontics, School of Dentistry, Aristotle University of Thessaloniki, Greece.
J Orofac Orthop. 2006 Jul;67(4):261-71. doi: 10.1007/s00056-006-0607-8.
The aim of this prospective study was to radiographically assess root morphology changes in maxillary and mandibular premolars following Herbst appliance treatment.
Twenty-five consecutive adolescents (19 boys and six girls, mean age 13.08 years) with Class II, Division 1 malocclusion were treated with the banded Herbst appliance for a mean period of 13.16 months. Periapical radiographs of the upper and lower premolars were obtained before appliance insertion and immediately after appliance removal using the parallel technique. All radiographs were scanned, digitized and analyzed using appropriately adjusted cephalometric software. The pre- and post-treatment length and area of the first and second maxillary and mandibular premolar roots were calculated. Statistical analysis included paired t-tests to evaluate pre- and posttreatment changes, and independent t-tests to compare the pre and post-treatment differences between the first and the second premolars, which served as controls. The level of significance was set at p <or= 0.05 for all tests.
No statistically significant decrease in premolar root lengths or areas was noted following removal of the Herbst appliance. We observed a statistically-significant decrease in the root area of the first mandibular premolars compared to that of the second mandibular premolars.
Although we observed no statistically-significant root morphology changes in the first and second premolars following Herbst appliance treatment, the mandibular first premolars revealed significantly more root resorption than did the mandibular second premolars.
本前瞻性研究旨在通过影像学评估Herbst矫治器治疗后上颌和下颌前磨牙的牙根形态变化。
连续选取25例安氏II类1分类错牙合青少年患者（19例男性，6例女性，平均年龄13.08岁），使用带环Herbst矫治器治疗，平均治疗时间为13.16个月。在矫治器戴入前及拆除后即刻，采用平行投照技术获取上下颌前磨牙的根尖片。所有根尖片均进行扫描、数字化处理，并使用适当调整后的头影测量软件进行分析。计算治疗前后上颌和下颌第一、二前磨牙牙根的长度和面积。统计分析包括配对t检验以评估治疗前后的变化，以及独立t检验以比较作为对照的第一前磨牙和第二前磨牙治疗前后的差异。所有检验的显著性水平设定为p≤0.05。
拆除Herbst矫治器后，未观察到前磨牙牙根长度或面积有统计学意义的减小。与下颌第二前磨牙相比，我们观察到下颌第一前磨牙的牙根面积有统计学意义的减小。
尽管在Herbst矫治器治疗后，第一和第二前磨牙未观察到有统计学意义的牙根形态变化，但下颌第一前磨牙的牙根吸收明显多于下颌第二前磨牙。
