Ng'ang'a P M, Ng'ang'a R N
Department of Paediatric Dentistry and Orthodontics, Faculty of Dental Sciences, University of Nairobi, P.O. Box 19676, Nairobi, Kenya.
East Afr Med J. 2003 Feb;80(2):101-4.
To evaluate, radiographically, the root forms of maxillary incisors in a sample of patients seeking orthodontic treatment in Nairobi, Kenya.
A retrospective study of maxillary incisor root forms based on periapical radiographs.
A private dental clinic in Nairobi, Kenya.
The study comprised 393 maxillary incisors in 100 consecutive subjects (51 boys, 49 girls) aged 9-24 years. Intra-oral periapical radiographs of the incisors were evaluated. An index was used to categorise the roots as follows: 0=normal, 1=short, 2=blunt, 3=apical bend, 4=pipette apex.
Normal root form was recorded in 60%, short in 12.5%, blunt in 7%, apical bend in 13%, and pippete-apex in 7% of the roots. Sixty nine percent of the pippete-apex roots were in central incisors and 94% of the roots with apical bend were in lateral incisors. Seventy three percent of short roots were in females.
Based on evidence from previous studies on risk of root resorption which indicates that pipette and blunt roots are the forms mostly involved in this phenomenon, the present data imply that about 14% of the roots may have been at risk of moderate to severe resorption during fixed orthodontic treatment.
通过影像学评估肯尼亚内罗毕寻求正畸治疗的患者样本中上颌切牙的牙根形态。
基于根尖片对上颌切牙牙根形态进行回顾性研究。
肯尼亚内罗毕的一家私人牙科诊所。
该研究包括100名年龄在9至24岁的连续受试者（51名男孩，49名女孩）的393颗上颌切牙。对切牙的口内根尖片进行评估。使用一个指数将牙根分类如下：0 = 正常，1 = 短，2 = 钝，3 = 根尖弯曲，4 = 滴管尖。
60%的牙根记录为正常形态，12.5%为短根，7%为钝根，13%为根尖弯曲，7%为滴管尖。69%的滴管尖根位于中切牙，94%的根尖弯曲根位于侧切牙。73%的短根见于女性。
基于先前关于牙根吸收风险的研究证据，表明滴管尖根和钝根是最常参与此现象的形态，目前的数据表明，在固定正畸治疗期间，约14%的牙根可能有中度至重度吸收的风险。
