• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.1
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• pp.46-52
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• 2002

Purpose : We examined the relationships between the root curvatures of the mandibular third molars and their locations on the mandible, so that it might be contributed to elucidate the origin of the formation and development of the Korean mandibular third molar and help many clinicians to treat the mandibular third molars. Materials and Methods : Panoramic radiographs of 237 patients who had been treated at Korea University Ansan Hospital from March, 2000 to April, 2001 and had bilateral mandibular third molars were examined and analyzed. Results : There was no statistically significant difference between men and women (p<0.05). But there were significantly fewer subjects with bilateral curved roots in bilateral third molars regardless of their status (p<0.01) and were statistically significant differences between the groups with bilateral curved roots in the mandibular third molars with same status and with unilateral curved roots in the mandibular third molars with different status and between the groups with unilateral curved roots in the mandibular third molars with same status and with bilateral curved roots in the mandibular third molars with different status(p<0.05). Subjects with bilateral curved roots in the mandibular third molars with bilateral partial impacted status and with bilateral curved roots in the mandibular third molars with bilateral complete eruption status were significantly fewer (p<0.01) and subjects with the mandibular third molars with partial impacted and complete impacted status and with the mandibular third molars with complete erupted and partial impacted status had significantly fewer bilateral curved roots (p<0.05). Conclusions : When we postulate that it is genetic and environmental factors that affect the root formation, it seems that environmental factors have more effects on the formation of the mandibular third molars than on that of the mandibular first and second molars

• The korean journal of orthodontics
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• v.9 no.1
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• pp.117-123
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• 1979

The aspects examined in the present study concerning the location and position of the lower third molar and the interrelationships of this molar, the gonial angle, and the second lower molar in subjects aged 8-24 are based on measurements made from 472 orthopantomograms. The following conclusion were drawn on the basis of the present study. 1. The gonial angle decreased with age, but slight enlarging occurred in the age group 20-21. 2. The angulation of the third molar in relation to the second molar did not correlate with the size of the gonial angle but decreased with developmental stage. 3. The mesial angle between the longitudinal axis of the second molar and the mandibular base line correlated significantly with the gonial angle. The above angle were smaller in Class II, Divison 2 and larger in Class III than in Class I and Class II, Division 1. 4. The rate of presence of lower third molar was 74.4%.

• The Journal of the Korean dental association
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• v.41 no.1 s.404
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• pp.42-47
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• 2003

Dental professions recommend that mandibular impacted third molar be extracted for the prevention of osteomyelities crneoplasm or for the treatment of halitosis. Even the possibility of emergence of unexpected halitosis after the preventive extraction exists, there are few studies describing the unexpected halitosis. This study intended to measure the emergence of halitosis after extraction of mandibular impacted third molar. Thirty-eight patients who visited Daejin Medical Center participated in this study. Halitosis was objectively measured using Halimeter in 3 intervals-before, after I day, after 7 days. Third factors, scaling and gender, which may influence the halitosis were analyzed with stratification. This study finds that in general halitosis decreased after 1 day but increased after 7 days. Scaling was helpful in decreasing halitosis and women have less severe halitosis than men. The effects of time interval(p<0.05), gender(p=0.836), and scaling(p=0.7929) on the severity of halitosis were not statistically significant. However, since this study's patients are neither a representative sample nor a random sample, all data interpretation was focused on clinical significance instead of conventional statistical significance. Clinical significance of this study's findings are: 1) scaling should be conducted in advance, 2) men should be notified of the higher possibility of halitosis.

• The Journal of the Korean dental association
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• v.56 no.1
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• pp.42-48
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• 2018

INTRODUCTION The most commonly impacted tooth is the third molar. An impacted third molar can ultimately cause acute pain, infection, tumors, cysts, caries, periodontal disease, and loss of adjacent teeth. Local anesthesia is employed for removing the third molar. This study aimed to evaluate the efficacy and safety of 2% lidocaine with 1:80,000 or 1:200,000 epinephrine for surgical extraction of bilateral impacted mandibular third molars. METHODS Sixty-five healthy participants underwent surgical extraction of bilateral impacted mandibular third molars in two separate visits while under local anesthesia with 2% lidocaine with different epinephrine concentration (1:80,000 or 1:200,000) in a double-blind, randomized, crossover trial. Visual analogue scale pain scores obtained immediately after surgical extraction were primarily evaluated for the two groups receiving different epinephrine concentrations. Visual analogue scale pain scores obtained 2, 4, and 6 h after administering an anesthetic, onset and duration of analgesia, onset of pain, intraoperative bleeding, operator's and participant's overall satisfaction, drug dosage, and hemodynamic parameters were evaluated for the two groups. RESULTS There were no statistically significant differences between the two groups in any measurements except hemodynamic factors (P > .05). Changes in systolic blood pressure and heart rate following anesthetic administration were significantly greater in the group receiving 1:80,000 epinephrine than in that receiving 1:200,000 epinephrine ($P{\leq}01$). CONCLUSION The difference in epinephrine concentration between 1:80,000 and 1:200,000 in 2% lidocaine liquid does not affect the medical efficacy of the anesthetic. Furthermore, 2% lidocaine with 1:200,000 epinephrine has better safety with regard to hemodynamic parameters than 2% lidocaine with 1:80,000 epinephrine. Therefore, we suggest using 2% lidocaine with 1:200,000 epinephrine rather than 2% lidocaine with 1:80,000 epinephrine for surgical extraction of impacted mandibular third molars in hemodynamically unstable patients.

• Journal of Korean Dental Science
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• v.9 no.2
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• pp.63-68
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• 2016

Pressure root resorption can be observed during the eruption of permanent dentition, especially of the maxillary canines (affecting lateral incisors) and mandibular third molars (affecting mandibular second molars). Since the cause of root resorption of the adjacent affected teeth is evident, treatment simply involves extraction of the impacted tooth. However, there have been few reports on the prognosis of the remaining resorbed tooth, as dentists often choose to extract them when damage due to root resorption is observed. We report a case involving a tooth that was severely resorbed due to pressure from an adjacent impacted tooth. After extraction of the impacted tooth, the remaining tooth retained vital pulp and survived as a functional tooth.

• Archives of Craniofacial Surgery
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• v.18 no.2
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• pp.73-75
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• 2017

The management of mandibular angle fractures is often challenging and results in the highest complication rate among fractures of the mandible. In addition, the optimal treatment modality for angle fractures remains controversial. Traditional treatment protocols for angle fractures have involved rigid fixation with intraoperative maxillomandibular fixation (MMF) to ensure absolute stability. However, more recently, non-compression miniplates have gained in popularity and the use of absolute intraoperative MMF as an adjunct to internal fixation has become controversial. In this article, the history of, and current trends in, the treatment of mandibular angle fractures will be briefly reviewed. In addition, issues regarding the management of the third molar tooth will be discussed.

• The Journal of the Korean dental association
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• v.19 no.2 s.141
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• pp.181-185
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• 1981

In this study an attempt has been made to throw some light on the problem of the mandibular third molar on measurement made from 302 orthopantomograms of patients at the age of 8 to 20 years. The following conclusions were drawn on the basis of the present study. 1. The amount of growth from the lower first molar to the anterior border of the ramus from 8 years to 14 years was 7.9mm in the male and 7.5mm in the female. The growth from 15years 20 years was 4.5mm in the male and 2.6mm in the female. 2. The growth from the lower first molar to the posterior border of the ramus from 8 years to 14 years was 10mm in the male and 9.8mm in the female. The growth occurred after that was 5.8mm in the male and 2.0mm in the female. 3. The difference between A and C measurements for the various age groups remained fairly constant in the male and female.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.1
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• pp.35-44
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• 2022

The aim of this study is to evaluate the development of the left mandibular third-molar development with modified Demirjian method and its relation to chronological age. A total of 1653 digital panoramic radiographs of healthy individuals aged between 7 and 23 years who visited Yonsei University Dental hospital were selected. The developmental status of the left mandibular third molars was assessed using dental maturity scoring proposed by Demirjian et al. The mean age of the first appearance of mineralization, complete crown formation, and complete root formation were around 9, 14, 21 years respectively. Statistically significant differences between males and females in the development stage of D and G were revealed that crown formation and root length completion were attained earlier in males than in females. There was significant positive relationship between age and third molar development in both sexes, and new formula was presented to estimate age of children and adolescents based on their developmental stages of third molars. In this study, the use of left mandibular third molar as a developmental marker is appropriate, and age estimation can be attained with dental maturity stage.

• Archives of Craniofacial Surgery
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• v.20 no.6
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• pp.376-381
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• 2019

Background: This study was conducted to determine the relationship between third molar (M3) and mandibular fracture. Methods: Patients with unilateral mandibular angle or condyle fractures between 2008 and 2018 were evaluated retrospectively. Medical records were reviewed regarding the location of fractures, and panoramic radiographs were reviewed to discern the presence and position of ipsilateral mandibular third molars (M3). We measured the bony area of the mandibular angle (area A) and the bony area occupied by the M3 (area B) to calculate the true mandibular angle bony area ratio (area A-B/area A×100). Results: The study consisted of 129 patients, of which 60 (46.5%) had angle fractures and 69 (53.5%) had condyle fractures. The risk of angle fracture was higher in the presence of M3 (odds ratio [OR], 2.2; p< 0.05) and the risk of condyle fracture was lower in the presence of M3 (OR, 0.45; p< 0.05), than in the absence of M3. The risk of angle fracture was higher in the presence of an impacted M3 (OR, 0.3; p< 0.001) and the risk of condyle fracture was lower in the presence of an impacted M3 (OR, 3.32; p< 0.001), than in the presence of a fully erupted M3. True mandibular angle bony area ratio was significantly lower in the angle fractures than in the condyle fractures (p= 0.003). Conclusion: Angle fractures had significantly lower true mandibular angle bony area ratios than condyle fractures. True mandibular angle bony area ratio, a simple and inexpensive method, could be an option to predict the mandibular fracture patterns.

• Imaging Science in Dentistry
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• v.43 no.2
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• pp.105-109
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• 2013

Purpose: Preoperative radiographic assessment of the mandibular third molars is essential to prevent inferior alveolar nerve damage during extraction. The purpose of this study was to assess the reliability of panoramic signs of association between the roots of teeth and the canal, and to compare the panoramic signs with cone beam computed tomography (CBCT) findings. Materials and Methods: CBCT images of 132 impacted mandibular third molars were evaluated to determine the association of the root to the canal. The CBCT findings were compared with the corresponding panoramic images. Logistic regression analysis was used to define the diagnostic criteria of the panoramic images. Results: Among the panoramic signs, loss of the cortical line was the most frequent radiographic sign predicting association (sensitivity: 79.31). Contact of the tooth with the canal was observed in all cases in which the loss of cortical line of the canal or darkening of the roots was found on the panoramic radiographs. Conclusion: Darkening of the roots and loss of the cortical line on panoramic radiographs might be highly suggestive of the risk of nerve injury.