Canuto Luiz Filiphe Gonçalves, de Freitas Karina Maria Salvatores, de Freitas Marcos Roberto, Cançado Rodrigo Hermont
Dental Press J Orthod. 2013 Sep-Oct;18(5):121-7. doi: 10.1590/s2176-94512013000500020.
Evaluate axial mesiodistal inclinations of the mandibular molars in orthodontically treated cases, analyzing whether inclusion of second mandibular molars in treatment mechanics has any influence on final and postretention molars angulations.
The sample comprised 150 panoramic radiographs of 50 patients. Patients were treated with extraction of four first premolars and divided into 2 groups: Group 1 comprised 25 subjects without inclusion of mandibular second molars during orthodontic treatment, whereas Group 2 comprised 25 subjects with inclusion of mandibular second molars. Panoramic radiographs at three observation times were evaluated: pretreatment, posttreatment and postretention. The statistical analysis included one-way analysis of variance (ANOVA) for intragroup evaluation and independent t-tests for intergroup comparisons.
Intragroup analysis demonstrated significant uprighting of mandibular first and second molars during treatment in Group 2, which remained stable during the postretention stage. Intergroup comparison demonstrated that Group 2 presented first and second molars significantly more uprighted in relation to Group 1 in both post-treatment and postretention stages.
It was concluded that inclusion of mandibular second molars in the orthodontic mechanics is relevant not only to correct the angulation of these teeth, but also to aid mandibular first molars uprighting.
评估正畸治疗病例中下颌磨牙的近远中轴向倾斜度,分析正畸治疗力学中纳入下颌第二磨牙是否会对最终及保持后的磨牙角度产生影响。
样本包括50例患者的150张全景X线片。患者均拔除四颗第一前磨牙,并分为两组:第一组25例,正畸治疗期间未纳入下颌第二磨牙;第二组25例,正畸治疗期间纳入下颌第二磨牙。评估三个观察时间点的全景X线片:治疗前、治疗后及保持后。统计分析包括组内评估的单因素方差分析(ANOVA)和组间比较的独立t检验。
组内分析表明,第二组治疗期间下颌第一和第二磨牙显著直立,在保持期保持稳定。组间比较表明,在治疗后和保持后阶段,第二组的第一和第二磨牙相对于第一组显著更直立。
得出的结论是,正畸力学中纳入下颌第二磨牙不仅与矫正这些牙齿的角度有关,而且有助于下颌第一磨牙直立。