A radiographic comparison of apical root resorption after orthodontic treatment with a standard edgewise and a straight-wire edgewise technique

The purpose of this study was to compare the severity of apical root resorption occurring in patients treated with a standard edgewise and a straight-wire edgewise technique, and to assess the influence of known risk factors on root resorption incident to orthodontic treatment. The sample consisted of 80 patients with Angle Class II division 1 malocclusions, treated with extraction of at least two maxillary first premolars. Variables recorded for each patient included gender, age, ANB angle, overjet, overbite, trauma, habits, invagination, agenesis, tooth shedding, treatment duration, use of Class II elastics, body-build, general factors, impacted canines, and root form deviation. Forty patients were treated with a standard edgewise and 40 with a straight-wire edgewise technique, both with 0.018-inch slot brackets. Crown and root lengths of the maxillary incisors were measured on pre- and post-treatment periapical radiographs corrected for image distortion. Percentage of root shortening and root length loss in millimetres were then calculated. There was significantly more apical root resorption (P < 0.05) of both central incisors in the standard than in the straight-wire edgewise group. No significant difference was found for the lateral incisors. Root shortening of the lateral incisors was significantly associated with age, agenesis, duration of contraction period (distalization of incisors), and invagination, while root shortening of the central incisors was related to treatment group and trauma.     

Radiographic evaluation of apical root resorption with 2 different types of edgewise appliances

Summary The purpose of this paper was to compare radiographically the prevalence and degree of apical root resorption after treatment with a fully programmed edgewise appliance (FPA) and a partly programmed edgewise appliance (PPA) in a randomized multipractice clinical trial. Two groups of patients with Class II malocclusions were treated orthodontically. The type of treatment was randomly assigned by a computer program. During fixed appliance therapy, one group was treated according to the precepts of the straight wire concept (FPA; n=32) while the other was treated with conventional full edgewise mechanics (PPA; n=29). Treatment times were recorded. Radiographs of the maxillary incisors were made before and after active treatment with fixed appliance using the bisecting angle technique. To correct for different projecting angles the pairs of radiographs were digitally reconstructed. The prevalence and degree of root resorption were assessed. The mean treatment time was 1.8 years and 1.6 years for treatment with FPA and PPA, respectively. The mean amount of loss of tooth length was 8.2% for the patients treated with FPA and 7.5% for the patients treated with PPA. No statistically significant differences could be assessed between both groups at the end of active treatment. The mean prevalence of apical root resorption was 75% for the patients treated with FPA and 55% for the patients treated with PPA. Statistical evaluation showed no significant differences. We concluded that the prevalence and degree of root resorption is independent of the appliances as used in this study.     

Apical root resorption of upper first molars as related to anchorage system

Night-time use of extra-oral traction for anchorage may cause jiggling, rotational and extrusional forces. The purpose of the study was to test the hypothesis that headgear forces in an anchorage system may increase the risk of radiographically detectable root resorptions on molar teeth. Twenty-one patients were selected among patients planned for orthodontic treatment, in which there was a need of anchorage in a full-bond appliance during a period of at least 6 months. An experimental group of 11 patients was given reinforcement anchorage in the maxilla with an extra-oral traction (cervical-pull) during night. Ten patients in a control group was given anchorage by a Goshgarian palatal bar, or by Class II-elastics. Periapical radiographs were taken of the upper first molars according to a standardised technique at the start of treatment, and at 3 and 6 months. Recordings included also patient compliance, force evaluation and the measurement of tooth movement. Significant reduction of root length was shown for some roots already after 3 months. However, mean root resorption after 6 months did not exceed 0.6 millimeter in any upper first molar root of the present sample. The degree of root resorption was similar in the experimental and the control groups. The hypothesis of a significant effect on root resorption of upper first molars by night-time use of extra-oral traction for a 6 month period was rejected. It is concluded that patients given anchorage by night-time use of extra-oral traction will show similar degrees of root resorption of the upper molars as those in which anchorage is given by a Goshgarian bar or Class II elastics.     

Vertical root fracture: Factors related to identification

Background

Vertical root fracture (VRF) requires root removal. Diagnostics for proper identification are critical. The author conducted a study to relate subjective, objective, and radiographic findings for VRF identification. They noted visual changes of root and overlying bone patterns after flap reflection.

青少年正畸治疗中影响牙根吸收的因素探讨

目的：探讨影响青少年错[牙合]畸形患者正畸矫治后牙根吸收的相关因素。方法：选择已完成正畸固定矫治的青少年患者78例．在其矫治前后的曲面断层片上,对4个上切牙进行根尖形态的分析,以获得正畸矫治后牙根吸收的定性数据。在对受试者按年龄、性别、牙位、牙龄、拔牙与否及疗程分组后,利用SPSS12．0软件对所得数据进行非参数检验分析。结果：所有正畸患者都存在一定程度的牙根吸收,根尖形态分析显示：①牙龄ⅣA期患者比ⅢC期的患者存在更严重的牙根吸收（P〈0．01）,但按年龄比较不存在显著差异;②拔牙组比不拔牙组有更加严重的牙根吸收（P〈0．01）;③疗程越长,牙根吸收也越明显（P〈0．05）;④牙根吸收的严重程度与性别及上切牙牙位之间无相关性。结论：在第二恒磨牙完全建验前（ⅣA期前）进行正畸治疗、不拔牙矫治、缩短矫治疗程,均可以减少正畸治疗中的牙根吸收。     

正畸治疗导致牙根吸收的影响因素和诊断评估

牙根吸收是正畸治疗的常见并发症.正畸治疗中牙根吸收的影响因素及其作用机制尚无明确定论.本文从影响正畸治疗中牙根吸收的生物因素和机械因素作一,并简单介绍临床常用诊断方法 和目前牙根吸收评价方法 的研究进展.     

Dental root resorption

This article presents a review of physiologic mechanisms involved in various types of root resorption that may be encountered clinically. Included is a brief overview of suggested homeostatic mechanisms of the periodontal ligament and the role of the intermediate cementum in inhibiting root resorption. Root resorption (surface, inflammatory, and replacement) associated with traumatic injuries is discussed, with emphasis on etiology and the ability to provide treatment. The final discussion relates to other types of resorption, based on a classification of internal, cervical, and external resorption associated with periradicular pathosis and resulting from pressure in the periodontal ligament.     

Factors related to the quantity of subgingival calculus in proximal root surfaces

The aim of this study was to determine the association between the quantity of subgingival calculus and the following factors: type and severity of periodontal disease, age, gender and tobacco consumption. A sample of 622 periodontal patients was studied. The radiographically detectable subgingival calculus in proximal root surfaces was recorded in periapical radiographs, considering the number of surfaces without calculus and the number of surfaces exhibiting deposits equal or greater than I mm. The association between the subgingival calculus and the factors under study was analyzed by distinct non-parametric tests. A statistically significant association was found between the absence/presence of subgingival calculus and the type and severity of periodontal disease (p<0.001), tobacco consumption (p=0.0049) and age (p<0.001). The quantity of radiographically-detectable subgingival calculus increased with increasing age and severity of the disease. However, the reverse association was found in smokers, which presented more surfaces free of calculus (p=0.0377) and less surfaces exhibiting deposits equal or greater than 1 mm. The amount of subgingival calculus decreased as the quantity of tobacco consumed increased (p=0.0129), and such differences were more significant in those smoker patients with severe periodontitis (p= 0.0065). An explanation is presented to justify these latter findings, since most literature supports that the presence of calculus is higher in smokers. According to the results of this study, more radiographically-detectable subgingival calculus in proximal root surfaces was found with increasing severity of the disease, with increasing age and with the absence of tobacco consumption.     

Orthodontic and nonorthodontic root resorption: their impact on clinical dental practice

Occasionally, general dentists are challenged with providing restorative treatment for a postorthodontic patient who has had moderate to severe root resorption. When this happens, a number of questions about the cause of such resorption and the appropriate treatment arise in the dentist's mind. This article will describe the orthodontic and restorative management of three patients with severe maxillary incisor root resorption, provide a thorough discussion of the currently available literature on the topic of root resorption, and answer clinical questions regarding this relatively infrequent but devastating sequel to orthodontic treatment.     

Radiographic diagnosis of root resorption in relation to orthodontics

The literature regarding external root resorption in relation to orthodontics and its radiographic diagnosis is reviewed, including a summary of the more common radiographic techniques available. Sample cases are presented which demonstrate the need for good radiographic technique and an awareness of the limitations of certain radiographs. A provisional diagnosis of external root resorption may need to be confirmed by further radiographic views where appropriate.     

Peripheral inflammatory root resorption

External resorptions associated with inflammation in marginal tissues are many times misdiagnosed and confused with caries and internal resorptions. A lack of uniformity in nomenclature has added to the confusion. This paper reviews the literature and presents cases to illustrate a rational approach to diagnosis and treatment. A new name is suggested to better reflect the features of this type of root resorption: peripheral inflammatory root resorption.     

Multiple idiopathic root resorption

A rare case of multiple idiopathic root resorption (MIRR) involving 5 adjacent anterior and posterior teeth is presented and the pathogenesis discussed. The proposition is made that MIRR results from microbiologically-induced osteoclast activity facilitated by prior osteoblast activation.     

Cervical external root resorption

Cervical external root resorption is frequently confused with internal resorption, yet a correct diagnosis is of great importance because the methods of treating these two conditions differ fundamentally. Views on the aetiology of cervical external root resorption are disparate, but it seems most plausible that the cause is chronic inflammation of periodontal tissues.