Ahangar Atashi Mohammad Hossein
Assistant Professor, Department of Orthodontics, Faculty of Dentistry, Tabriz University of Medical Sciences, Iran.
J Dent Res Dent Clin Dent Prospects. 2007 Spring;1(1):13-8. doi: 10.5681/joddd.2007.003. Epub 2007 Jun 10.
Malocclusion with its great hazardous effects seems to have become more prevalent in recent decades; therefore, the present study was carried out to assess the prevalence of different malocclusions among 13-15 year-old adolescents in Tabriz.
The subjects in the present study consisted of 398 adolescents aged 13-15, who were randomly selected from 5 different districts of the city. Students who had previous orthodontic treatment or extraction of any permanent teeth were excluded from the study. Angle's classification was used to describe the type of malocclusion and the evaluation of other aspects of malocclusion such as overjet, overbite and crowding were considered the minor goals of the study. The prevalence of different types of malocclusion in the population under study was estimated.
According to the results of the study, only 4% of 13-15 year-old adolescents under study had normal occlusion, whereas 51% had Class I, 21.9% had Class II [17.6% div 1, 4.3% div 2] and 17.1% had Class III malocclusion. With respect to overjet, the study revealed that 30.7% of the population under study had increased overjet, 33.9% had decreased overjet and 2% had reverse overjet. Increased overbite was observed in 40.2% of the population studied, whereas decreased overbite was found in 19.3%, deep bite was noted in 3.3% and open bite was detected in 3.3% of the studied population.
Class I malocclusion was the most prevalent, whereas Class III malocclusion was the least prevalent among adolescents aged 13-15 in Tabriz.
错牙合畸形具有极大的危害，近几十年来似乎变得更为普遍；因此，本研究旨在评估大不里士13至15岁青少年中不同错牙合畸形的患病率。
本研究的受试者包括398名13至15岁的青少年，他们是从该市5个不同地区随机选取的。曾接受过正畸治疗或拔除过任何恒牙的学生被排除在研究之外。采用安氏分类法描述错牙合畸形的类型，对错牙合畸形其他方面（如覆盖、覆牙合和牙列拥挤）的评估被视为研究的次要目标。估计了研究人群中不同类型错牙合畸形的患病率。
根据研究结果，在被研究的13至15岁青少年中只有4%的人牙合正常，而51%的人是安氏I类错牙合，21.9%的人是安氏II类错牙合[其中17.6%为1分类，4.3%为2分类]，17.1%的人是安氏III类错牙合。关于覆盖，研究显示30.7%的研究人群覆盖增加，33.9%的人覆盖减小，2%的人有反覆盖。40.2%的研究人群中观察到覆牙合增加，而19.3%的人覆牙合减小，3.3%的人有深覆牙合，3.3%的研究人群中检测到开牙合。
在大不里士13至15岁的青少年中，安氏I类错牙合最为普遍，而安氏III类错牙合最不普遍。
