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.     

Apical root resorption in patients treated with comprehensive orthodontics

External apical root resorption (EARR) is a common--but seldom extreme--consequence of orthodontic treatment. Incisors are most at risk, perhaps because of their single roots and because they typically are moved farther than other teeth. We followed a cohort of patients (n = 153) treated with comprehensive orthodontics. EARR was scored on the upper incisors with a qualitative five-grade ordinal scale. There was no EARR at the start of treatment, but most (> 80%) exhibited slight-to-moderate EARR by the end of treatment (i.e., a loss of 1-2 mm). Cases treated with premolar extractions experienced more EARR because their incisors were retracted farther; however, the sum of the effects of patients' sex and age, and severity of the malocclusion, and the kind of mechanics used accounts for little of the overall variation in EARR. Instead, it appears that genetically-based inter-individual variation in susceptibility to EARR is the most influential factor. Research should be directed at understanding the biochemical nature of susceptibility so prospective patients can be screened to identify those at particular risk.     

牙根尖外吸收与正畸治疗研究现状

牙根尖外吸收是正畸治疗的最普遍的医源性结果,是正畸医生不希望出现的情况,本文就牙根尖外吸收的流行病学、诊断方法、坪价方法、影响因素及临床策略作一综述。     

Constant versus dissipating forces in orthodontics: the effect on initial tooth movement and root resorption

The aim of this clinical and confocal laser scanning microscopic study was to compare the effects of two frequently used archwires on tooth movement and root resorption. A total of 84 premolars in 27 individuals (10 boys, 17 girls, with a mean age of 12.5 years) was moved buccally with an experimental fixed orthodontic appliance. In a split mouth experimental design the premolar on one side was activated with a stainless steel wire with a buccal offset of 1 mm, which was reactivated every four weeks and the contralateral premolar was moved with a superelastic wire with a force plateau of 0.8-1 N. This wire had an initial activation of 4.5 mm and was not reactivated during the 12-week experimental period. At the end of the experimental period the teeth were extracted. Six premolars were used as control teeth and were extracted before the experiment started. Tooth displacement was studied three-dimensionally on dental casts with a co-ordinate measuring machine. The depth, perimeter, area, and volume of the resorption lacunae was measured using three-dimensional digital images made with a confocal laser scanning microscope (CLSM). On these images the resorbed portions of the root surface were 'reconstructed' mathematically. The results show that the teeth activated with the superelastic wire moved significantly more than the teeth with the steel wire during the experimental period. The depth of the resorption lacunae did not differ significantly between the groups; however, perimeter, area, and volume of the resorption lacunae on the teeth of the 'superelastic group' were 140 per cent greater than on the teeth of the 'steel group'. It may be concluded that a greater amount of tooth movement occurred with superelastic wires, offering a force level of 0.8-1 N compared with stainless steel wires, with initially higher but rapidly declining forces in an experimental set up for a period of 12 weeks. The amount of root resorption was significantly larger in the superelastic group.     

Apical resorption in pre-surgical orthodontics

Apical root resorption is a frequent phenomenon observed in pre-surgical orthodontic; the reason is double: we deal with adult patients and we often move the teeth in the opposite direction compared to the position obtained in previous inefficacious orthodontic treatments. Notwithstanding the amount of apical root resorption we couldn't record an hyper-mobility of the teeth and a long term evaluation of occlusal stability didn't show any significant change.     

External root resorption: its implication in dental traumatology, paedodontics, periodontics, orthodontics and endodontics

Summary. The aetiology and pathogenesis of three types of root resorption—surface, inflammatory and replacement—are reviewed, and their occurrence after certain types of orthodontic, periodontal, paedodontic and endodontic treatment is described.     

口腔正畸治疗要点Ⅲ.正畸诊疗中不可忽视的危险因素

正畸治疗的主要目标是美观、功能和稳定。在我国，特别是近十年来，口腔正畸事业的发展速度很快，正畸医师的人数成倍增长。由于正畸医师的教育背景不同，其治疗水平参差不齐。虽然远不及外科手术，但正畸治疗仍存在着一定程度的风险。因此，每一位正畸医师都有必要了解正畸诊疗中的高危因素。只有充分掌握相关知识，才能避免或减少正畸治疗中可能遇到的风险，保证正畸治疗顺利进行。现将正畸治疗中的高危因素介绍如下。     

Comparative study of root resorption of maxillary incisors in patients treated with lingual and buccal orthodontics

Objective:To compare the magnitude of external apical root resorption (EARR) of maxillary incisors in patients with mild to moderate anterior crowding, treated with lingual and conventional (labial) orthodontics.Materials and Methods:The sample comprised 40 patients divided into two groups: lingual (20 patients) and conventional buccal brackets (20 patients). Patient ages ranged from 11 to 45 years, and the study included 12 men and 28 women. Apical root resorption was measured from periapical radiographs obtained at the beginning of treatment (T1) and at the end of the leveling phase (T2). Periapical radiographs were scanned and transferred to the CorelDraw X7 image-processing program, in which measurements of root lengths were performed. For intragroup and intergroup comparisons between the T1 and T2 phases, paired and independent t-tests, respectively, were used at 5% significance.Results:There was significant apical root resorption for all teeth evaluated; the magnitude of the EARR (T2−T1) ranged from −0.35 mm to −0.63 mm in the lingual group, and from −0.66 mm to −0.85 mm in the conventional group. Although there was an intergroup variation in the magnitude of EARR observed, no statistically significant differences were found. Neither group presented any teeth with resorption ≥1 mm.Conclusions:The magnitude of apical root resorption in maxillary incisors in patients with anterior crowding was similar regardless of orthodontic technique, lingual or conventional. Both techniques resulting in an apical rounding considered clinically insignificant.     

Internal inflammatory root resorption: the unknown resorption of the tooth

Internal inflammatory root resorption is a relatively rare resorption that begins in the root canal and destroys surrounding dental hard tissues. Odontoclastic multinuclear cells are responsible for the resorption, which can grow to perforate the root if untreated. The initiating factor in internal root resorption is thought to be trauma or chronic pulpal inflammation, but other etiological factors have also been suggested. Active, expanding resorption requires vital pulp tissue and continuous microbiological irritation, likely from the necrotic coronal part of the root canal. In its classical form, internal root resorption is easy to diagnose. However, in many instances advanced diagnostic methods may be required for a definitive diagnosis. Internal root resorption is usually symptom free, but in cases of perforation, a sinus tract usually forms. The prognosis for treatment of small lesions of internal root resorption is very good. If, however, the tooth structure is greatly weakened and perforation has occurred, the prognosis is poor and tooth extraction must be considered. Sodium hypochlorite, ultrasonic instrumentation and calcium hydroxide are the cornerstones of treatment of internal inflammatory root resorption. Mineral trioxide aggregate is being increasingly used as a root canal filling material, particularly in cases of perforation.     

牙根外吸收四例病例分析

牙根外吸收是发生在有牙周附着的牙根外表面硬组织的病理性吸收,由于临床症状不典型、临床检查手段局限,病变早期常难以发现,以致漏诊、误诊,延误了治疗时机.现将4例典型的牙根外吸收病例报告、分析如下,供同行借鉴,共同提高诊治水平.     

Exploring the third dimension in root resorption

OBJECTIVE: To review and investigate the validity of various 2D quantitative measurement techniques, and to explore the third dimension of root resorption. DESIGN: A review of the literature involving various quantitative evaluation of root resorption. RESULTS: Quantitative evaluation of resorption using radiographs has proven to be highly inaccurate because of magnification errors and their inability to be readily repeated and reproduced. Studies using histology sections of samples have proven to be laborious and technique sensitive. Inherent parallax errors and loss of material in data transfer have denied the true understanding of this 3D event. CONCLUSION: With the evolution in computing technology and digital imaging, the vision of evaluating the extent of root resorption in 3D has materialized. It was demonstrated that 3D volumetric quantitative evaluation of root resorption craters was feasible and its accuracy and repeatability was high.     

正畸牙根吸收与龈沟液中牙本质涎磷蛋白和牙本质涎蛋白相关性的实验研究

目的 探讨大鼠龈沟液中牙本质涎磷蛋白(DSPP)和牙本质涎蛋白(DSP)的表达与实验性牙移动所致牙根吸收的关系.方法 36只健康Wistardd大鼠随机分成3组:对照组、轻力组、重力组.以上颌切牙为支抗,轻力组和重力组分别以0.392、0.98 N力拉右侧上颌第一磨牙向近中移动.加力7 d后,提取龈沟液,制备实验牙及其...     

Multiple idiopathic root resorption: diagnostic considerations

Multiple idiopathic root resorption is a specific entity that must be delineated from all other resorptive processes. We present a case report and discuss the diagnostic possibilities that must be considered before arrival at this diagnosis.     

Healing of root resorption: a case report

External resorption is sequelae of necrotic periodontal membrane over a large area of root following an injury to the tooth. This usually occurs after severe dental injuries such as intrusion, severe luxations or exarticulation injuries complicated by a prolonged extra oral period. This case report presents a clinical and radiographic follow up (13 months) of treatment of inflammatory external root resorption on maxillary central incisor using Vitapex. Gradual healing of resorption was observed radiographically with no tenderness or pathological mobility.     

Idiopathic root resorption: report of a case

A case of multiple idiopathic apical root resorption in a 26-yr-old female patient is presented. A review of the literature revealed that extensive idiopathic root resorption is unusual. Neither local nor systemic etiological factors were found in our case. Examination of parents and siblings did not reveal a familiar tendency. Radiographs and clinical evaluation showed a very poor prognosis for most of the teeth present in the mouth of our patient.     

Generalized idiopathic root resorption: a case report

BACKGROUND: Cases of generalized idiopathic root resorption have been reported in the literature. However the majority of previously reported cases have affected adults, and it has been rare that a possible link to a medical condition has been found. CASE REPORT: The subject of this case report was 11 years old when generalized root resorption was first diagnosed. This case report is unusual in that the resorption may be connected to a bone dysplasia. The possible medical diagnoses and links to tooth resorption have been discussed for this very rare case. CONCLUSION: The investigation into the exact diagnosis of the patient and the treatment of tooth resorption is still ongoing and has required input from many disciplines of Medicine and Dentistry.     

External apical root resorption: two case reports

Aim To present two cases of external root resorption and in so doing highlight rarer causative factors as well as the difficulties in classifying root resorption. Summary Root resorption in the permanent dentition is usually pathological. Local factors are the most frequent causes of resorption, most commonly excessive pressure and inflammation. However, many systemic abnormalities have been implicated in the resorption process. Resorption is often an incidental finding during routine examination. Otherwise, late in the disease process, tooth mobility or infection may arise. A rarer form of root resorption is external apical root resorption which may or may not be linked to systemic disease. In most cases, no causative factors are found. At present there is no curative treatment for external apical root resorption. The current management for these patients is symptomatic, minimal intervention and long‐term monitoring. Key learning points ? Apical resorption may be associated with a systemic disease or of an idiopathic origin. It may also occur in association with orthodontic treatment or with pathoses such as tumours, cysts, etc. ? In the absence of signs or symptoms of pulpal and/or periapical disease, endodontic treatment is not indicated. ? Long‐term monitoring of affected patients is essential.