• Imaging Science in Dentistry
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• v.43 no.4
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• pp.219-225
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• 2013

Purpose: The purpose of this study was to determine the prevalence of missing and impacted third molars in people aged 25 years and above. Materials and Methods: The study sample of 3,799 patients was chosen randomly from patients who visited Pusan National University Dental Hospital and had panoramic radiographs taken. The data collected included presence and impaction state, angulation, and depth of impaction of third molars, and radiographically detected lesions of third molars and adjacent second molars. Results: A greater percentage of men than women retained at least one third molar. The incidence of third molars decreased with increasing age. The incidence of partially impacted third molars greatly declined after the age of 30. Vertically impacted maxillary third molars and horizontally impacted mandibular third molars were most frequent in all age groups. Among the maxillary third molars, those impacted below the cervical line of the second molar were most frequent in all age groups, and among the mandibular third molars, deeply impacted third molars were most frequent in those aged over 40. Dental caries was the most common radiographic lesion of the third molars. Mesioangularly impacted third molars showed radiographic lesions in 13 (9.5%) adjacent maxillary second molars and 117 (27.4%) mandibular second molars. Conclusion: The number of remaining third molars decreased and the percentage of Class C depth increased with age. Caries was the most frequent lesion in third molars. Partially impacted mesioangular third molars showed a high incidence of caries or periodontal bone loss of the adjacent second molar. Regular oral examination will be essential to keep asymptomatic third molars in good health.

• Journal of Korean Dental Science
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• v.9 no.1
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• pp.42-48
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• 2016

Prophylactic removal of impacted third molars is a common procedure in dentistry, but the necessity of routine extraction is still controversial. When impacted third molars caused severe apical root resorption of the second molars, orthodontic traction of the third molars after extraction of the damaged second molars could minimize alveolar bone defect and preserve the patient's natural teeth. By well-planned orthodontic treatment, functional occlusion was established avoiding extraction of the impacted teeth and eliminating the possibility of a large bone defect after extraction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.42 no.5
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• pp.251-258
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• 2016

Objectives: The aim of this retrospective study was to investigate factors associated with increased difficulty in the surgical extraction of impacted lower third molars and to improve identification of difficult cases. Materials and Methods: A total of 680 patients who required 762 surgical extractions of impacted lower third molars from 2009 to 2014 were enrolled in the study. Demographic factors, clinical factors, radiographic factors, surgical extraction difficulty, and presumed causes of difficulty were collected. Data were statistically analyzed using IBM SPSS Statistics version 23. Results: Age, sex, depth of impaction, and blurred radiographic image influenced difficulty in surgical extraction. The position of the impacted tooth influenced surgical difficulty, especially when it was accompanied by other factors. Conclusion: It is challenging to design a reliable and practical instrument to predict difficulty in surgical extraction of impacted lower third molars. To identify very difficult cases, root investigation using computed tomography is advised when impacted tooth position suggests difficult extraction.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.48 no.3
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• pp.155-158
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• 2022

Objectives: The aim of this study was to observe the relationship between impacted mandibular third molars and development of temporomandibular joint (TMJ) disorders. Knowledge of the factors that have an adverse effect on the TMJ is necessary for proper diagnosis, treatment, and prognosis of TMJ disorders. Materials and Methods: The study was performed on 80 patients aged between 20 and 60 years with impacted mandibular third molars, over a period of two months. The patients were examined clinically and radiologically to determine the type of impaction and detect the associated TMJ symptoms or disorders. Results: In the 80 patients, 63.8% (51/80) of TMJ disorders were found in the horizontal group, 46.3% (37/80) in the mesioangular group, 42.5% (34/80) in the distoangular group, and 30.0% (24/80) in the vertical group of impacted mandibular third molars. Conclusion: The study concluded that type of impacted mandibular third molar is factor in the development of temporomandibular disorders.

• The korean journal of orthodontics
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• v.11 no.2
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• pp.77-83
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• 1981

The author analyzed the morphological pattern of mandibles and lower third molars in order to study and predict the impaction of the developmental third molars. The subjects consisted of 37 males and 87 females with malocclusion. The following results were obtained: 1. The mandible was shown to be shorter in the impacted third molar group than in the erupted group, both in over-all length and in body length. 2. The developmental mesial angulation of the third molar to the mandibular plane was higher in the impacted third molar group. 3. There was a tendency for impacted third molars to be slightly larger than those which erupted except Class II malocclusion in female. 4. In the available space for the eruption of the third molar, significant space deficiency was found in association with the impacted third molar group compared with the erupted group.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.37 no.5
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• pp.343-348
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• 2011

Introduction: Third molar extraction is one of the most common procedures in oral and maxillofacial surgery. The impacted third molar causes many pathological conditions, such as pericoronitis, caries, periodontitis, resorption of adjacent teeth, and cyst or tumors associated with impacted teeth. Extraction is often considered the treatment of choice for impacted lower third molars. On the other hand, imprudent extraction of deeply impacted third molars can cause permanent complications, such as inferior alveolar nerve damage. Therefore, guidelines for the extraction of lower third molars should be set to prevent embarrassing complications. This study examined the indication and current trends of the extracted lower third molars in the dental hospital of a dental college. Materials and Methods: 557 extracted third molars were evaluated at the department of oral and maxillofacial surgery of Yonsei University. The chief complaint, diagnosis, age and degree of impaction were analyzed to determine the tendency for the extraction of asymptomatic lower third molars. Results: The percentage of asymptomatic third molars was 40.8%. In cases of full impacted tooth or full erupted tooth, the percentage of asymptomatic teeth was more than 50% (52.4% and 54.3, respectively). Among those partially impacted teeth, 73.1% of them showed symptoms, such as pain, tenderness and swelling. In terms of age, pericoronitis was evident at a younger age, and dental caries/periodontitis was the main cause of removal in those aged over 50. Twenty nine cases (1.6%) had teeth associated with pathological changes Conclusion: The incidence of pathological changes to the lower third molar was relatively low. Surgical extraction is recommended in cases of partially impacted teeth. In Korea, the incidence of asymptomatic third molar extraction was relatively higher than in European countries. More careful attention would be desirable to consider the risks and benefits of lower third molar extraction.

• 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

• Imaging Science in Dentistry
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• v.53 no.2
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• pp.137-144
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• 2023

Purpose: This study aimed to evaluate the anatomic circle around the impacted lower third molar to show, document, and correlate essential findings that should be included in the routine radiographic assessment protocol as clinically meaningful factors in overall case evaluation and treatment planning. Materials and Methods: Cone-beam computed tomographic images of impacted lower third molars were selected according to specific inclusion criteria. Impacted teeth were classified according to their position before assessment. The adjacent second molars were assessed for distal caries, distal bone loss, and root resorption. The fourth finding was the presence of a retromolar canal distal to the impaction. Communication with the dentist responsible for each case was done to determine whether these findings were detected or undetected by them before communication. Results: Statistically significant correlations were found between impaction position, distal bone loss, and detected distal caries associated with the adjacent second molar. The greatest percentage of undetected findings was found in the evaluation of distal bone status, followed by missed detection of the retromolar canal. Conclusion: The radiographic assessment protocol for impacted third molars should consider a step-by-step evaluation for second molars, and clinicians should be aware of the high prevalence of second molar affection in horizontal and mesioangular impactions. They also should search for the retromolar canal due to its associated clinical considerations.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.27 no.1
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• pp.69-77
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• 2001

PURPOSE : The Purpose of this study was to investigate the anti-inflammatory effect on combination dosage of dexamethasone and naproxen after removal of impacted 3rd molars. We evaluated postoperative pain, swelling, and mouth opening limitation quantitatively. PATIENTS AND METHODS : Removal of an impacted lower third molar was done under local anesthesia with 2% lidocaine to 239 healthy patients. We randomly gave experimental group 1.5mg dexamethasone and 200mg naproxen three times a day for postoperative 2days, and also gave control group 200mg naproxen alone three times a day for postoperative 2days. Swelling and pain were measured by visual analogue scale (VAS). Mouth opening limitation was measured by maximum interincisal opening length. We estimated these measurements in the first and second postoperative days. Differences between experimental and control group were investigated considering age, sex, BMI(body mass index), impacted type, surgical site(right or left), and operation time by independent student T-test. RESULTS : In general, swelling, pain, and mouth opening limitations were significantly reduced (p<0.01) by combination dose of dexamethasone and naproxen in postoperative one day. But there was no difference in pain on the second postoperative day. As variables being considered, in the postoperative pain, there was significant difference between experimental group and control group in only male, little bony removal group, left side extraction group. In case of postoperative swelling, there was no significant differences in male, adolescence, long operating time group (over 20 minutes), medium BMI group and right side extraction group. In case of postoperative mouth opening limitation, there was significant difference between only female and long operating time group (over 20 minutes). CONCLUSION : Variables being considered, postoperative swelling was more reduced by the combination dose of naproxen and dexamethasone than that of naproxen alone after removal of impacted 3rd molars. But there was varoius results in pain and mouth opening limitation.

• Journal of Dental Anesthesia and Pain Medicine
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• v.23 no.3
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• pp.163-171
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• 2023

Background: Surgical extraction of impacted mandibular third molars is the most common procedure performed by oral surgeons. The procedure cannot be performed effectively without achieving profound anesthesia. During this procedure, patients may feel pain during surgical bone removal (at the cancellous level) or during splitting and luxation of the tooth, despite administration of routine nerve blocks. Administration of intraosseous (IO) lignocaine injections during third molar surgeries to provide effective anesthesia for pain alleviation has been documented. However, whether the anesthetic effect of lignocaine is the only reason for pain alleviation when administered intraosseously remains unclear. This conundrum motivated us to assess the efficacy of IO normal saline versus lignocaine injections during surgical removal of impacted mandibular third molars. The aim of this study was to assess the efficacy of IO normal saline as a viable alternative or adjunct to lignocaine for alleviation of intraoperative pain during surgical removal of impacted mandibular third molars. Methods: This randomized, double-blind, interventional study included 160 patients who underwent surgical extraction of impacted mandibular third molars and experienced pain during surgical removal of the buccal bone or sectioning and luxation of the tooth. The participants were divided into two groups: the study group, which included patients who would receive IO saline injections, and the control group, which included patients who would receive IO lignocaine injections. Patients were asked to complete a visual analog pain scale (VAPS) at baseline and after receiving the IO injections. Results: Of the 160 patients included in this study, 80 received IO lignocaine (control group), whereas 80 received IO saline (study group) following randomization. The baseline VAPS score of the patients and controls was 5.71 ± 1.33 and 5.68 ± 1.21, respectively. The difference between the baseline VAPS scores of the two groups was not statistically significant (P > 0.05). The difference between the numbers of patients who experienced pain relief following administration of IO lignocaine (n=74) versus saline (n=69) was not statistically significant (P > 0.05). The difference between VAPS scores measured after IO injection in both groups was not statistically significant (P >0.05) (1.05 ± 1.20 for the control group vs. 1.72 ± 1.56 for the study group) Conclusion: The study demonstrates that IO injection of normal saline is as effective as lignocaine in alleviating pain during surgical removal of impacted mandibular third molars and can be used as an effective adjunct to conventional lignocaine injection.