• Restorative Dentistry and Endodontics
• /
• 제26권2호
• /
• pp.121-123
• /
• 2001

Idiopathic external root resorption is an apparently infrequently occurrence involving single or multiple teeth. Presented is an unusual case of multiple external root resorption associated with craniopharyngioma. Although the cause of this resorption was not determined, several possibilities are discussed. The literature to a systemic etiology for external root resorption is briefly reviewed.

• 대한치과보존학회:학술대회논문집
• /
• 대한치과보존학회 2001년도 춘계학술대회
• /
• pp.243-244
• /
• 2001

Root resorption is conventionally divided into internal and external varieties. Internal resorption occurs where there is loss of the internal wall of the root canal. and is usually associated with a localized area of necrotic pulp(Trope '||'&'||' Chivian 1984). External resorption occurs where there is loss of the external surface of the root and the resorption may be either transient or progressive(Tronstad 1988). External inflammatory resorption usually occurs following damage to the periodontal ligament or where there is communication between the periodontal ligament and a necrotic pulp. via open dentinal tubules or accessory canals. This type of resorption is usually progressive until root canal treatment is instituted (Barclay 1993).

• 대한치과교정학회지
• /
• 제51권4호
• /
• pp.241-249
• /
• 2021

Objective: This study aimed to evaluate the volume, amount, and localization of root resorption in the maxillary first premolars using micro-computed tomography (micro-CT) after expansion with four different rapid maxillary expansion (RME) appliances. Methods: In total, 20 patients who required RME and extraction of the maxillary first premolars were recruited for this study. The patients were divided into four groups according to the appliance used: mini-implant-supported hybrid RME appliance, hyrax RME appliance, acrylic-bonded RME appliance, and full-coverage RME appliance. The same activation protocol (one activation daily) was implemented in all groups. For each group, the left and right maxillary first premolars were scanned using micro-CT, and each root were divided into six regions. Resorption craters in the six regions were analyzed using special CTAn software for direct volumetric measurements. Data were statistically analyzed using Kruskal-Wallis one-way analysis of variance and Mann-Whitney U test with Bonferroni adjustment. Results: The hybrid expansion appliance resulted in the lowest volume of root resorption and the smallest number of craters (p < 0.001). In terms of overall root resorption, no significant difference was found among the other groups (p > 0.05). Resorption was greater on the buccal surface than on the lingual surface in all groups except the hybrid appliance group (p < 0.05). Conclusions: The findings of this study suggest that all expansion appliances cause root resorption, with resorption craters generally concentrated on the buccal surface. However, the mini-implant-supported hybrid RME appliance causes lesser root resorption than do other conventional appliances.

• 치과방사선
• /
• 제10권1호
• /
• pp.29-33
• /
• 1980

An ameloblastoma produces more extensive resorption of the teeth on which it encroaches than do most of the other lesions. In this study, intraoral and extraoral radiographs of 78 cases of ameloblastoma were observed and the root resorption associated with ameloblastoma was classified into four types of resorption. With these, the following conclusions were obtained. 1. The root resorption was observed in 72 cases of ameloblastoma. (92.3%) 2. In the aspect of resorptive changes of 424 roots observed, 342 roots showed smooth resorption. (80.6%) 3. The 424 roots associated with ameloblastoma revealed the following radiographic features. a) Root apex resorption in contact with the lesion appeared in 189 roots. (44.5%) b) The resorption of roots projected into the lesion appeared in 147 roots. (34.6%) c) Slight resorption of root surface in contact with the lesion was observed in 56 roots. (13.2%) d) Loss of lamina dura and periodontal space without root resorption were observed in 32 roots. (7.7%)

• 대한치과교정학회지
• /
• 제24권3호
• /
• pp.649-658
• /
• 1994

The purpose of this study was to evaluate the association between incisor root resolution and sex, age, extraction, the magnitude and direction of tooth movement. The sample consisted of 189 randomly selected orthodontic patients, receiving standard edgewise orthodontic treatment in three private orthodontic onces at San Francisco. Pre-treatment and post-treatment periapicals and cephalometric radiographs were digitized. Measurements and superimpositions were made utilizing a computerized cephalometric analysis program. The variables were statistically analyzed. The results were as follows: 1. Mean apical root resorption values were $0.77{\pm}2.08mm$ for upper right central incisor, $0.88{\pm}2.11mm$ for upper left central incisor, $-0.05{\pm}2.09mm$ for lower right central incisor and $0.11{\pm}1.85mm$ for lower left central incisor. Apical root resorption of upper incisor was greater than lowers. 2. No correlation was found between sex and apical root resorption. 3. Apical root resorptions in adolescents were smaller than those in adults. 4. Apical root resorption was not affected by extraction. 5. Apical root resorption values of upper incisor were correlated to the horizontal and vertical movement of apex; Apical root resorption values of lower incisor were correlated to the vertical movement of apex.

• Imaging Science in Dentistry
• /
• 제41권1호
• /
• pp.17-21
• /
• 2011

Purpose : The purpose of this study was to examine the patient- and treatment-related etiologic factors of external root resorption. Materials and Methods : This study consisted of 163 patients who had completed orthodontic treatments and taken the pre- and post-treatment panoramic and lateral cephalometric radiographs. The length of tooth was measured from the tooth apex to the incisal edge or cusp tip on the panoramic radiograph. Overbite and overjet were measured from the pre- and post-treatment lateral cephalometric radiographs. The root resorption of each tooth and the factors of malocclusion were analyzed with an analysis of variance. A paired t test was performed to compare the mean amount of root resorption between male and female, between extraction and non-extraction cases, and between surgery and non-surgery groups. Correlation coefficients were measured to assess the relationship between the amount of root resorption and the age in which the orthodontic treatment started, the degree of changes in overbite and overjet, and the duration of treatment. Results : Maxillary central incisor was the most resorbed tooth, followed by the maxillary lateral incisor, the mandibular central incisor, and the mandibular lateral incisor. The history of tooth extraction was significantly associated with the root resorption. The duration of orthodontic treatment was positively correlated with the amount of root resorption. Conclusion : These findings show that orthodontic treatment should be carefully performed in patients who need the treatment for a long period and with a pre-treatment extraction of teeth.

• Imaging Science in Dentistry
• /
• 제42권3호
• /
• pp.147-154
• /
• 2012

Purpose: This study was performed to evaluate the incidence and degree of external apical root resorption of maxillary incisors after orthodontic treatment and to evaluate particular associated factors related to external apical root resorption. Materials and Methods: The records and maxillary incisor periapical radiographs of 181 patients were investigated. Crown and root lengths were measured and compared on the pre- and post-treatment periapical radiographs. Crown length was measured from the center of the incisal edge to the midpoint of the cemento-enamel junction (CEJ). Root length was measured from the CEJ midpoint to the root apex. A correction factor for the enlargement difference was used to calculate root resorption. Results: The periapical radiographs of 564 teeth showed that the average root resorption was $1.39{\pm}1.27$ ($8.24{\pm}7.22$%) and $1.69{\pm}1.14$ mm ($10.16{\pm}6.78%$) for the maxillary central and lateral incisors, respectively. The results showed that the dilacerated or pointed roots, maxillary premolar extraction cases, and treatment duration were highly significant factors for root resorption (p<0.001). Allergic condition was a significant factor at p<0.01. Age at the start of treatment, large overjet, and history of facial trauma were also factors significantly associated with root resorption (p<0.05). There was no statistically significant difference in root resorption among the factors of gender, overbite, tongue-thrusting habit, types of malocclusion, and types of bracket. Conclusion: These results suggested that orthodontic treatment should be carefully performed in pre-treatment extraction patients who have pointed or dilacerated roots and need long treatment duration.

• 대한치과교정학회지
• /
• 제24권3호
• /
• pp.621-630
• /
• 1994

The purpose of this study was to evaluate root resorption and alveolar bone resorption pattern by jiggling movement. 16 adult cats were divided into 4 groups(6, 12, 18, 24 days). In test side, mesio-distal jiggling force was applied in right maxillary 1st premolar in 3 days cycle In control side, mesial force was applied in left maxillary 1st premolar. Radiographic and histologic observation were performed in 6, 12, 18, 24 days after force application. The results were as follow: 1. Alveolar bone resorption was more severe by jiggling force than by unidirectional force. 2. Root resorption pattern was not different between jiggling force and unidirectional force. 3. Combined pattern of bone resorption and new bone formation appeared in jiggling group. 4. New bone formation began to appear at periapical area of jiggling group after 24 days, because alveolar bone resorption was severe and extrusion resulted.

• Restorative Dentistry and Endodontics
• /
• 제37권4호
• /
• pp.228-231
• /
• 2012

Invasive cervical resorption is a relatively uncommon form of external root resorption. It is characterized by invasion of cervical region of the root by fibrovascular tissue derived from the periodontal ligament. This case presents an invasive cervical resorption occurring in maxillary lateral incisor, following damage in cervical cementum from avulsion and intracoronal bleaching procedure. Flap reflection, debridement and restoration with glass ionomer cement were performed in an attempt to repair the defect. But after 2 mon, more resorption extended apically. Considering root stability and recurrence potential, we decided to extract the tooth. Invasive cervical resorption in advanced stages may present great challenges for clinicians. Therefore, prevention and early detection must be stressed when dealing with patients presenting history of potential predisposing factors.

• 대한치과교정학회지
• /
• 제7권1호
• /
• pp.7-11
• /
• 1977

The purpose of this study was to investigate the resorption potential in human permanent teeth by analyzing the frequency and the degree of root resorption as revealed by routine intraoral roentgenograms. The following conclusions were obtained: 1) The distribution of root resorptions was as follows; a) 65.3 per cent were no root resorption. b) 7.0 per cent showed questionable root shortening. c) 25.2 per cent were definite root shortening. d) 2.5 per cent showed very severe resorption. 2) The order of susceptibility of teeth to resorption in this study was consistent with other studies. 3) The maxillary teeth showed a much higher incidence (52.2 per cent) than the mandibular teeth (17.1 per cent) 4) The sex ratio of the sample in this study was 1.3 female to 1 male.