• Maxillofacial Plastic and Reconstructive Surgery
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• 제23권3호
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• pp.238-243
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• 2001

Purpose : The purpose of this study was to determine radiologic variables affecting extraction of impacted mandibular third molar. Materials and Methods : This study was investigated on 44 consecutive extractions of unilateral impacted mandibular third molars (Male;34, Female;10, Mean age;24.98, Age range;19-35). Fourteen radiologic variables, which were actual value except only one, were evaluated to establish their relation to the operation time. The Pearson correlation coefficient and Stepwise procedures for regression analysis were carried out. Results : Eight variables (depth, angulation, ramus width, relationship to the second molar, distal ramus depth, mesial ramus depth, mesial periodontal ligament width and follicle) showed a statistically significant relation to the operation time(Pearson correlation coefficient, p<0.05). Two variables, depth and mesial periodontal ligament width, showed the most powerful and just relation to the operation time($r^2$ = 0.349, p<0.05). Conclusion : This study shows that our results can help general practioner to estimate the operation time of extraction of impacted mandibular third molars by measuring two radiologic variables ; depth and mesial periondontal ligament width.

• Imaging Science in Dentistry
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• 제49권3호
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• pp.213-218
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• 2019

Purpose: The aim of this study was to evaluate the relationship between the mandibular canal and impacted mandibular third molars using cone-beam computed tomography (CBCT) and to compare the CBCT findings with signs on panoramic radiographs(PRs). Materials and Methods: This retrospective study consisted of 200 mandibular third molars from 200 patients who showed a close relationship between the mandibular canal and impacted third molars on PRs and were referred for a CBCT examination of the position of the mandibular canal. The sample consisted of 124 females and 76 males, with ages ranging from 18 to 47 years (mean, $25.75{\pm}6.15$ years). PRs were evaluated for interruption of the mandibular canal wall, darkening of the roots, diversion of the mandibular canal, and narrowing of the mandibular canal. Correlations between the PR and CBCT findings were statistically analyzed. Results: In total, 146 cases(73%) showed an absence of canal cortication between the mandibular canal and impacted third molar on CBCT images. A statistically significant relationship was found between CBCT and PR findings (P<0.05). The absence of canal cortication on CBCT images was most frequently accompanied by the PR sign of diversion of the mandibular canal(96%) and least frequently by interruption of the mandibular canal wall(65%). Conclusion: CBCT examinations are highly recommended when diversion of the mandibular canal is observed on PR images to reduce the risk of mandibular nerve injury, and this sign appears to be more relevant than other PR signs.

• Journal of Dental Anesthesia and Pain Medicine
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• 제16권2호
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• pp.131-136
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• 2016

Background: This study aimed to evaluate the patient's pain and quality of life after suture removal at either 3 or 7 days following the bilateral surgical extraction of impacted lower third molars. Methods: This study was a prospective, randomized controlled clinical trial carried out in 30 patients, who acted as their own control. Each patient required the bilaterally impacted mandibular third molars to be extracted. The impacted teeth were removed and the wound margins were approximated and sutured with black braided silk. The suture material was removed on day 3 on one side and on day 7 on the other. Each participant was asked to complete a questionnaire after the removal of the suture material on each designated day. Results: Regarding overall clinical symptoms, the mean VAS scores of male and female participants on day 3 were not significantly different from those on day 7. A significant difference was found in female participants, in that overall daily activity was better on day 7. There were significant differences in the ability to smile and laugh in both sexes and the ability to chew in the male participants was better on day 7. Conclusions: There were no significant differences in the patient's pain and quality of life between suture removal on day 3 or on day 7 following surgery to remove impacted lower third molars.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제33권6호
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• pp.505-511
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• 2011

Purpose: This study evaluated correlation and risk factors between position of the mandibular third molars and mandibular angle fractures using clinical and radiographic findings. Methods: Medical records and panoramic radiographs of 188 patients with mandibular fractures were retrospectively reviewed. The presence and position of the third molars were assessed for each patient and were related to the occurrence of mandibular angle fractures. Results: The incidence of mandibular angle fracture was found to be greater when a lower third molar was present, particularly at the occlusal plane positioned on the $2^{nd}$ molar occlusal surface (by Archer system) and the third molar is impacted in mandibular ramus (by Pell & Gregory system). Of the 192 sites with a lower third molar, 32 (16%) had an angle fracture. Of the 184 site without lower third molars, 16 (8%) had an angle fracture. Conclusion: This study confirmed an increased risk of angle fractures in the presence of a lower third molar as well as variable risk for angle fracture, depending on positioning of the third molar.

• Journal of Korean Dental Science
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• 제15권2호
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• pp.181-189
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• 2022

Molar incisor malformation (MIM) has been introduced as a new type of dental anomaly. Currently, the morphological and histological characteristics of MIM are known; however, its etiology has not been clearly identified. To date, the long-term prognosis of first permanent molars (FPM) affected by MIM has rarely been reported, and few treatment guidelines have been established. The purpose of this case report was to present guidelines for the extraction of FPM affected by MIM, depending on the presence of the third molar. In patients with a third molar, spontaneous mesial shift of the posterior molars might be induced by extracting the FPM at an appropriate time, that is, when the second permanent molar is at an early furcation stage of the tooth. However, it is recommended that FPM be preserved for as long as possible if a third molar does not exist. When an FPM needs to be extracted, it is suggested to consider space maintenance.

• Imaging Science in Dentistry
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• 제38권3호
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• pp.163-167
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• 2008

Purpose : The purpose of this study is to evaluate the position of the mandibular canal in relation to the mandibular third molar by cone beam CT in cases showing a close relationship between the third molar and the mandibular canal on the panoramic radiograph. Materials and Methods : The panoramic images and cone beam CT scans of 87 impacted mandibular third molars in 60 patients were evaluated to assess the tooth relationship to the mandibular canal. The clearness of the canal wall and the vertical depth of the lower third molar were evaluated on panoramic radiographs. The lower third molars were assessed using cone beam CT to determine the proximity and position of the canal relative to the roots. Results : In the 66 cases where the canal wall was unclear on the panoramic radiographs, 58 (87.9%) of the third molars had contact between the canal and root; 34 (51.5%) canals were showed an inferior position and 22 (33.3%) showed a linguoinferior position on cone beam CT. Conclusion : Interruption of the canal wall on panoramic radiographs was highly predictive of contact between the mandibular canal and the third molar. Cross sectional CT may be indicated for localization of the mandibular canal in such cases.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제39권5호
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• pp.242-245
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• 2013

Impacted mandibular third molars are located between the second mandibular molar and mandibular ramus. However, ectopic mandibular third molars with heterotopic positions are reported in the subcondylar or pterygomandibular space. The usual cause of malposition is a cyst or tumor, and malposition without a pathology is rare. This case report described an impacted mandibular third molar in the pterygomandibular space without any associated pathology.

• Restorative Dentistry and Endodontics
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• 제37권2호
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• pp.104-109
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• 2012

Objectives: The purpose of this study was to evaluate the buccolingual curvature at the apical one third in type II mesial canals of mandibular molars using the radius and angle of curvature. Materials and Methods: Total 100 mandibular molars were selected. Following an endodontic access in the teeth, their distal roots were removed. #15 H- or K-files (Dentsply Maillefer) were inserted into the mesiobuccal and mesiolingual canals of the teeth. Radiographs of the teeth were taken for the proximal view. Among them, type II canals were selected and divided into two subgroups, IIa and IIb. In type IIa, two separate canals merged into one canal before reaching the apex and in type IIb, two separate canals merged into one canal within the apical foramen. The radius and angle of curvature of specimens were examined. Results: In type II, mean radius of curvature in mesiolingual and mesiobuccal canals were 2.82 mm and 3.58 mm, respectively. The radius of the curvature of mesiolingual canals were significantly smaller than that of mesiobuccal canals in type II, and especially in type IIa. However, there were no statistically significant differences in radius of curvature between mesiobuccal and mesiolingual canals in type IIb and there were no significant differences in angle of curvature between type IIa and IIb. Conclusion: In this study, type II mesial canals of mandibular molars showed severe curvature in the proximal view. Especially, mesiolingual canals of type IIa had more abrupt curvature than mesiobuccal canals at the apical one third.

• Journal of Periodontal and Implant Science
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• 제36권2호
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• pp.503-513
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• 2006

The purpose of this study was to determine the distribution, prevalence and relationship of the localized periodontitis of root fusion in maxillary and mandibular molars. One hundred patients who had eight maxillary and mandibular molars(third molars excluded) were consecutively selected for the study subjects. The subjects provided a total of 800 molars, i. e., 400 maxillary and 400 mandibular molars. A decision about root fusion was made on the radiographic examination. Probing depth, plaque index, gingival index and mobility were measured. The results were as follows. 1. 15.9% of the molars had a fused root. 22% of the maxillary molars and 9.8% of the mandibular molars had a fused molars. 2. In maxillary molars, the results of probing depth, plaque index, gingival index, mobility are more higher in test group than in control group, and there was a significantly difference except plaque index of maxillary first molars group(p<0.01). 3. In mandibular molars, the results of probing depth, plaque index, gingival index, mobility are more higher in test group than in control group, and there was a significantly difference(p<0.01). As a result of this study, it can be concluded that, in management of molars with a root fusion, we should detect the molars through the precise radiographic examination, early periodontal treatment and systematic treatment plan should be chosen. And postoperative continuing supportive periodontal therapy is needed.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제36권5호
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• pp.408-412
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• 2010

Introduction: This study examined the depth of sedation and the usefulness of the monitoring tool in determining the level of sedation in patients undergoing third molars extraction under conscious sedation with midazolam. Materials and Methods: Twenty two patients undergoing third molars extraction at the department of Oral and Maxillofacial surgery, Ewha Womans Mokdong Hospital from February 2010 to April 2010 were analyzed. All patients were classified as American Society of Anesthesiologist (ASA) class I and had no contraindications tosedation. The bispectral index was recorded continually during surgery using a bispectral monitor. The initial sedation was accomplished using a 3 mg bolus of midazolam followed by a 2 mg bolus of midazolam until the level of sedation, at which the patient’s eyes were closed or the subject was responsive only to loud or repeated calling of their name, was reached. All subjects were surveyed with a postoperative questionnaire to evaluate the level of sedation. Results: The bispectral index (BIS) decreased approximately 5 minutes after midazolam administration, but increased at the local anesthesia injection and odontomy procedure. The amnestic effect was shown effectively in the early stages of surgery. Conclusion: Conscious sedation with intravenous midazolam is effective in achieving the effect of anxiolysis, analgesia and amnesia. The BIS is an objective and useful means of assessing the depth of sedation.