基于一项随机临床试验，探讨全景X线片在确定何时对腭侧移位尖牙患儿进行预防性拔牙有益方面的应用。

The use of panoramic radiographs to decide when interceptive extraction is beneficial in children with palatally displaced canines based on a randomized clinical trial.

作者信息

Naoumova Julia, Kjellberg Heidrun

机构信息

Specialist Clinic of Orthodontics, University Clinics of Odontology, Public Dental Service Västra Götaland Region, Göteborg, Sweden.

Department of Orthodontics, Institute of Odontology at the Sahlgrenska Academy, University of Gothenburg, Göteborg, Sweden.

出版信息

Eur J Orthod. 2018 Nov 30;40(6):565-574. doi: 10.1093/ejo/cjy002.

DOI:10.1093/ejo/cjy002

PMID:29462471

Abstract

OBJECTIVE

To evaluate which palatally displaced canines (PDCs) benefit from interceptive extraction of the deciduous canine, to assess possible side effects from the extraction, and to analyse other dental deviations in patients with PDCs.

DESIGN, SETTINGS, PARTICIPANTS, AND INTERVENTION: A sample of 67 patients (40 girls, mean age: 11.3 ± 1.1; 27 boys, mean age ± SD: 11.4 ± 0.9) with unilateral (45) or bilateral (22) PDCs were consecutively recruited and randomly allocated to extraction or non-extraction using block randomization. No patients dropped out after randomization or during the study. The patients were given a clinical examination and panoramic radiographs were taken at baseline and after 6 (T1) and 12 months (T2). An individual therapy plan was made for the PDCs that had not erupted at T2. Measurements were performed blindly and the outcome measures were: canine position and angulation, root development, midline shift, rotation, or movement of adjacent teeth into the extraction site, and frequency of other dental deviations.

RESULTS

Interceptive deciduous canine extraction is beneficial if the alpha angle is between 20 and 30 degrees. A PDC located in sector 4 with an alpha angle >30 degrees should have immediate surgical exposure, while canines angulated less than 20 degrees and located in sector 2 can be observed without prior interceptive extraction. Deciduous canine extraction was more beneficial in younger patients with less advanced root development. Minor side effects, such as rotation or migration of teeth into the extraction space, were observed in 15 out of 35 patients. A majority of the patients had other dental deviations than PDC in the dentition.

LIMITATIONS

The results are only valid for patients with no space deficiency in the maxilla and with PDCs located in sector 2-4.

HARMS

No harms were detected.

CONCLUSIONS

The alpha angle and sector position are good diagnostic predictors of when interceptive extraction is beneficial. Minor side effects are seen after the extraction and the majority of the patients had other dental deviations too.

REGISTRATION

This trial was registered at http://www.fou.nu/is/sverige, registration number: 211141.

摘要

目的

评估哪些腭向错位尖牙（PDC）能从乳牙尖牙的阻断性拔除中获益，评估拔除可能产生的副作用，并分析PDC患者的其他牙齿异常情况。

设计、地点、参与者和干预措施：连续招募了67例单侧（45例）或双侧（22例）PDC患者（40名女孩，平均年龄：11.3±1.1岁；27名男孩，平均年龄±标准差：11.4±0.9岁），采用区组随机化方法将其随机分为拔除组或非拔除组。随机分组后或研究期间无患者退出。患者接受了临床检查，并在基线时、6个月（T1）和12个月（T2）后拍摄全景X线片。为T2时仍未萌出的PDC制定了个体化治疗方案。测量由专人进行，观察指标包括：尖牙位置和角度、牙根发育情况、中线偏移、旋转情况、相邻牙齿向拔牙位点的移动情况以及其他牙齿异常的发生率。

结果

如果α角在20至30度之间，阻断性拔除乳牙尖牙是有益的。位于4区且α角>30度的PDC应立即进行外科暴露，而位于2区且角度小于20度的尖牙可在不进行预先阻断性拔除的情况下进行观察。乳牙尖牙拔除对牙根发育程度较低的年轻患者更有益。35例患者中有15例出现了轻微的副作用，如牙齿旋转或向拔牙间隙移动。大多数患者牙列中除了PDC还有其他牙齿异常情况。