Silvola Anna-Sofia, Arvonen Päivi, Julku Johanna, Lähdesmäki Raija, Kantomaa Tuomo, Pirttiniemi Pertti
Department of Oral Development and Orthodontics, Institute of Dentistry, University of Oulu, PO Box 5000, FI-90014 Oulu, Finland.
Angle Orthod. 2009 May;79(3):540-5. doi: 10.2319/021108-83.1.
To test the null hypothesis that early headgear (HG) treatment has no effect on the eruption pattern of the maxillary canines in the early mixed dentition.
Sixty-eight children (40 boys and 28 girls) with a Class II tendency in occlusion and moderate crowding of the dental arches were randomized into two groups. HG treatment was initiated immediately in the first group. In the second group only minor interceptive procedures were performed during the first follow-up period of 2 years. Orthopantomograms were taken at the baseline, three times at 1-year intervals, and after growth at the age of 16. Eruption geometry was performed. The space from the maxillary first molar to the lateral incisor was measured on the dental casts.
The inclination of the maxillary canine in relation to the midline appeared to be significantly more vertically oriented on the right side in the HG group 1 and 2 years after starting the HG therapy (P = .0098 and P = .0003, respectively). The inclination in relation to the lateral incisors was smaller in the HG group bilaterally after 1 year and 2 years of HG treatment, and on the right side after 3 years of treatment.
The hypothesis is rejected. Early HG treatment significantly affects the inclination of the maxillary canine during eruption. The strongest influence was seen after 2 years of HG use, more prominently in the right-side canine.
检验早期头帽（HG）治疗对乳牙混合早期上颌尖牙萌出模式无影响这一零假设。
68名有Ⅱ类错牙合倾向且牙弓中度拥挤的儿童（40名男孩和28名女孩）被随机分为两组。第一组立即开始HG治疗。第二组在最初2年的随访期内仅进行轻微的阻断性治疗。在基线、每隔1年进行3次以及16岁生长后拍摄曲面断层片。进行萌出几何学分析。在石膏模型上测量上颌第一磨牙到侧切牙的间隙。
在开始HG治疗1年和2年后，HG组右侧上颌尖牙相对于中线的倾斜度明显更垂直（分别为P = .0098和P = .0003）。在HG治疗1年和2年后，HG组双侧以及治疗3年后右侧上颌尖牙相对于侧切牙的倾斜度较小。
该假设被拒绝。早期HG治疗在尖牙萌出期间显著影响上颌尖牙的倾斜度。使用HG 2年后影响最强，右侧尖牙更为明显。
