Bolton指数指导正畸的临床应用

正畸治疗的目标就是要达到口颌系统功能的平衡,以及实现牙齿、颅、面型的美观和理想的咬合。Bolton于20世纪提出前牙比和全牙比的概念,并被广泛采纳和接受,成为错畸形的诊断、设计和预测错畸形治疗的一个常规指标和重要方法。Bolton指数还受很多因素的影响,但其决定因素还有待研究。     

近中水平阻生下颌第三磨牙的矫治探索

目的探索保存和利用近中水平阻生下颌第三磨牙的矫治方法,以期保留更多的近中水平阻生的下颌第三磨牙。方法利用自行研制的磨牙胎面正轴装置及磨牙远中正轴装置,配合下颌固定矫治器,对近中水平阻生的下颌第三磨牙进行矫治。结果利用本研究方法对10例11颗近中水平阻生的下颌第三磨牙进行17．26个月矫治,均取得第三磨牙直立、稳定、覆胎覆盖关系正常的预期目标。结论利用磨牙殆面正轴装置及磨牙远中正轴装置,可快速、安全、高效地完成对近中水平阻生下颌第三磨牙的矫治。     

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目的    探讨大鼠实验性牙齿移动中不同正畸力对牙槽骨核因子κB受体活化因子配基（RANKL）表达的影响。方法    本研究于2010年9—12月在山西医科大学寄生虫实验室完成。选用健康雄性Wistar大鼠36只,随机分为对照组、轻力组、中力组、大力组（各9只）,分别施加0、0.29、0.49、0.98 N正畸力,建立大鼠牙齿移动模型。免疫组化法检测大鼠牙周组织压力侧RANKL的表达。结果    对照组RANKL有少量表达,主要分布于破骨细胞的胞核,正畸加力各组RANKL表达主要分布于压力侧牙周膜及骨改建区的破骨细胞,在基质细胞和牙周膜成纤维细胞也有表达,且其黄染程度强于对照组。各实验组牙周组织压力侧不同程度地出现血管被挤压、玻璃样变区和骨吸收陷窝。正畸力与RANKL的表达呈正相关（r = 0.834,P < 0.01）。结论    正畸力与大鼠牙槽骨压力侧RANKL的表达呈正相关,且0.49 N为促进RANKL表达的最佳力值。     

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口腔正畸学和牙周病学有着较广泛的联系。本文将从错牙合畸形对牙周组织的影响、牙周病患者在正畸治疗中的注意事项以及治疗后保持3个方面阐述正畸治疗与牙周病的关系,以期为牙周病患者的正畸治疗提供参考。     

Aggressive periodontitis diagnosed during or before orthodontic treatment

Abstract

Objective. The aim was to review the literature on aggressive periodontitis diagnosed during or before the initiation of orthodontic treatment and to propose preventive recommendations before, during and after orthodontic treatment. Materials and methods. Literature searches of free text and MeSH terms were performed by using PubMed, Embase and the Cochrane Library and the appropriate studies were selected. The retrieved articles were analyzed and the relevant data was tabulated according to different parameters. Results. A total of 220 articles were found in the preliminary search. Eighteen studies, all case reports, describing 21 cases from this search met all the criteria. The mean age of the reported cases was 21.12 years, all treated with combined periodontal and orthodontic modalities. Most of the reported cases were female. Conclusion. An interdisciplinary dental team must approve the periodontal health prior to and during the course of the orthodontic therapy. In subjects with periodontal pathology, a periodontal consultation and interceptive/corrective therapy should be performed prior to commencing with orthodontic treatment. Orthodontic treatment should be postponed or replanned in order to shorten treatment duration and reduce the orthodontic forces exerted on the aggressive periodontitis involved dentition.     

Effects of orthodontic magnets on cutaneous epithelial thickness and tibial bone growth in rats

The use of permanent magnets in orthodontic treatment has increased significantly over the past years, triggered by the introduction of rare earth magnetic alloys. Concerns about possible side effects have been expressed relating to their use in orthodontic treatment. In previous experimental studies evidence of a reduction in bone formation and epithelial turnover close to rare earth magnets has been presented. The aim of the present study was twofold: to confirm earlier results and to study whether the observed changes are reversible. One hind leg in each of 45 rats was fitted with aluminum rings with Co₅Sm magnets, whereas the other hind leg was fitted with sham rings. After 8 weeks 25 rats were killed, and the rings in the remaining rats were removed. The latter group was killed after another 11 weeks. The epithelial and bone reactions were evaluated histomorphometrically. Previous results showing thinner epithelium and retarded rate of bone formation close to Co₅Sm magnets were confirmed. These effects were also shown to be largely reversible. It was concluded on the basis of this and the magnitude of the effects that any local side effects from orthodontic rare earth magnets appear negligible when extrapolated to the clinical situation.     

Orally Administered Liposomal Lactoferrin Inhibits Inflammation‐Related Bone Breakdown Without Interrupting Orthodontic Tooth Movement

Background: Bovine lactoferrin (bLF) modulates the production of tumor necrosis factor‐alpha (TNF‐α) and inhibits alveolar bone breakdown associated with periodontitis. This study is designed to examine the effects of orally administered liposomal bLF (LbLF) on orthodontic force (OF)‐induced alveolar bone remodeling during experimental tooth movement. Methods: Two groups of male Wistar rats were treated with either LbLF or control solution in drinking water 7 days before OF application. Lipopolysaccharide (LPS) was injected into the gingival sulcus in half the rats in each group. Thus, four groups: OF, OF+LbLF, OF+LPS, and OF+LPS+LbLF were established. Results: Orally administered LbLF significantly reduced apical migration of junctional epithelium in the OF and OF+LPS groups. In OF+LPS, osteoclast number in the alveolar crestal area was increased by LPS treatment, whereas osteoclast number was significantly reduced in OF+LPS+LbLF through suppression of TNF‐α production. Osteoclastic induction in the middle part, mainly from OF application, was not affected by LbLF administration. Inhibition of tooth movement was not induced by LbLF. Conclusions: Orally administered LbLF significantly inhibits LPS‐induced alveolar bone resorption but not OF‐induced bone remodeling. LbLF could be a potent therapeutic and preventive agent to control periodontal inflammation in patients undergoing orthodontic treatment.     

Adult orthodontics in the absence of orthognathic treatment: a hospital perspective

Abstract

Objective: To examine adult orthodontic treatment within two hospital settings and ascertain whether any factors have a statistically significant effect on treatment outcomes.

Design: A retrospective observational study.

Materials and methods: Through the analysis of hospital case notes, variables relating to adult patients undergoing orthodontic treatment that did not involve orthognathic surgery between 1991 and 2008 at the Eastman Dental and Croydon University Hospitals, were studied. In addition, a proportion of study models were Peer Assessment Rating (PAR) scored to determine treatment outcome.

Results: Females accounted for 76·2% of the adults studied, with a mean age of 31·24 years. The most commonly presenting malocclusion was a class II division 1 incisor relationship on a class II skeletal base, with over half of all patients studied having missing teeth upon presentation. The mean treatment length was 2·29 years. Only the type of orthodontic treatment (orthodontic-only or multidisciplinary) and/or the presence of a crowded upper labial segment had a statistically significant effect on treatment outcomes, as measured by PAR scores.

Conclusion: This study has highlighted demographical and treatment trends from a cohort of adult patients studied within two hospital orthodontic departments. It also illustrates that a crowded upper labial segment and the type of treatment provided has a statistically significant effect on post-treatment PAR scores     

A survey of the first 6 years of experience with cone beam CT scanning in a teaching hospital orthodontic department

Abstract

Objective: Cone beam computed tomography (CBCT) is a specialized form of radiography and has been used in the Glasgow Dental Hospital since 2006. The clinical notes of all patients referred for CBCT from the orthodontic department between 2006 and 2011 were evaluated to determine the reasons for referral, scan parameters and clinical findings.

Design: Retrospective observational study.

Materials and methods: From a general database, the notes of patients from the Orthodontic Department of Glasgow Dental Hospital & School referred for CBCT imaging, since the inception of the service (2006 through to 2011) were examined. Information was obtained from CBCT request forms, case notes and radiology reports.

Results: During the chosen time period, 290 patients were referred for CBCT. Of these, 280 had clinical records that were available for investigation. Analysis showed approximately a third of scans were carried out within 4 weeks of referral. The smallest height of 4 cm was used for over a third of the scans investigated. Sixty-two per cent of the scans examined the maxilla only, 32% both jaws and 6% the mandible only. The two most common reasons for referral were to accurately determine the position of impacted teeth and to identify the presence of root resorption in relation to impacted teeth. In this cohort, 39% of teeth adjacent to an impacted tooth were found to have some root resorption, which closely supports the current literature.

Conclusions: This study provides a general overview of CBCT used by an orthodontic department in a teaching hospital environment.