• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.47 no.1
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• pp.15-19
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• 2021

Objectives: The aim of this study was to evaluate correlations between anxiety and preoperative pressure pain assessments and postoperative pain and analgesic requirements in impacted lower third molar tooth surgery. Materials and Methods: This prospective study enrolled 60 patients who underwent impacted lower third molar surgery. The preoperative State-Trait Anxiety Inventory-I (STAI-I), pressure pain threshold, and pressure pain tolerance scores were measured. At 2, 4, 6, 12, and 24 hours, and at 6 days following surgery, the patients scored their pain on the visual analogue scale and recorded their analgesic drug usage. The data were evaluated, and the results were statistically analyzed. Results: Of the 60 patients, 38 were female. Mean age was 24.62±7.42 years. The study found no relationship between preoperative pressure pain assessments and postoperative pain (P>0.05). There was also no relationship observed between preoperative STAI-I scores and postoperative pain (P>0.05). However, there was a positive correlation between operation time and total medication taken (P<0.05). Conclusion: Preoperative pressure pain threshold, pressure pain tolerance, and anxiety level had no significant effects on postoperative pain and analgesic requirements in impacted lower third molar surgery.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.6
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• pp.551-553
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• 2004

The displacement of an entire tooth into the adjacent anatomical area is an uncommon complication of a tooth extraction. We encountered a 23-year-old woman who had previously undergone surgery under local anesthesia to remove the lower third molar about 12 weeks prior and the upper third molar was extracted 2 days prior to visiting this hospital. Upon admission, she complained of a swallowing discomfort and a mouth opening limitation. Panoramic radiograph and a CT scan revealed a displacement of the entire tooth into the lateral pharyngeal space. The tooth was retrieved via the transoral approach under general anesthesia. The removed tooth had an indentation formed by a dental bur. Therefore, it was concluded that the tooth displaced into the lateral pharyngeal space was the lower third molar. This report describes an unusual case of a third molar that was displaced into the lateral pharyngeal space with a review of the relevant literature.

• The korean journal of orthodontics
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• v.34 no.2 s.103
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• pp.109-119
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• 2004

This study aimed at investigating the skeletal, dentoalveolar, and soft tissue changes of Class III malocclusion cases treated by second molar extraction. The lateral cephalograms of 15 subjects with moderate Class III malocclusion by average ANB $-1.4^{\circ}\;and\;IMPA\;85^{\circ}$ were traced and the computerized superimposition of average craniofacial change was made. The data was gathered and statistically analyzed. The results were as follows: 1 Lower anterior facial height/anterior facial height increased by 0.6%(P<0.01), mandibular plane increased by $1.5^{\circ}$(P<0.05). 2. There was a slightly downward & backward rotation of the mandible. 3. Lower first molar tipped distally by 4.nm(P<0.001), lower anterior teeth lingually tipped by $3.2^{\circ}$(P<0.05). 4. Retracted lower lip improved facial profile. This study may suggest that second molar extraction could be effective for a moderate Class III malocclusion to make distalization of the lower first molar easier and avoid severe lingual tipping of the lower incisor, if the lower third molar has a normal shape, good direction of eruption and adequate time for lower second molar extraction

• Journal of Oral Medicine and Pain
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• v.6 no.1
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• pp.23-34
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• 1981

In order to evaluate the correlation of age with development stage on permanent lower posterior teeth. the author exmined the roentgeregrams in standard films taken by intraoral technic and analysed the development phases of 1358 teeth of 500 males ranging from 9 to 15 years. The development was divided into 7 phases : Crown complete (Cr. C.). Root length 1/4(R. 1/4) Root length /2 (R. 1/2) Apical closure complete (A.C) The obtained results were as follows : 1. The formation of roots in full length on posterior teeth was complete as follow : a. Roots of 1st premolar : 12.72 years b. Roots of 2nd premolar : 12.94 years c. Meral Roots of 2nd molar : 13.38 years d. Distal Roots of 2nd molar : 13.46 years 2. The formation of apical forman of premolar was closured as follows : a. Apical foramen of root of 1st premolar : 13.64 years b. Apical foramen of root of 2nd premolar : 13.93 years 3. As a general rule. the mesial roots of second molar were developed earlier than distal roots of second molar. 4. In the correlation of age with the development stage, the regression equations. the correlation coefficents. and the sample numbers were “Y = 0.8370x + 10.2160, r = 0.71(p<0.01), n = 318”on lower first premolar, “Y = 0.6984x + 10.2148, r = 0.71(p<0.01), n = 385”on lower second premolar, “Y = 0.8810x + 10.2040, r = 0.65(p<0.01), n = 344”on mesial Root of lower second molar, and “Y = 0.7310x + 10.7940, r = 0.66(p<0.01), n = 311”on Distal Root of lower second molar respectively.

• Journal of Korean Dental Science
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• v.3 no.2
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• pp.4-11
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• 2010

Purpose: This study aimed at examining the thickness of lateral cortical bone in the mandibular posterior body and the location of the inferior alveolar nerve canal as well as investigating the clinically viable bone grafting site(s) and proper thickness of the bone grafts. Subjects and Methods: The study enrolled a total of 49 patients who visited the Department of Oral and Maxillofacial Surgery at Kyung Hee University Dental Hospital to have their lower third molar extracted and received cone beam computed tomography (CBCT) examinations. Their CBCT data were used for the study. The thickness of lateral cortical bone and the location of inferior alveolar nerve canal were each measured from the buccal midpoint of the patients' lower first molar to the mandibular ramus area in the occlusal plane of the molar area. Results: Except in the external oblique ridge and alveolar ridge, all measured areas exhibited the greatest cortical bone thickness near the lower second molar area and the smallest cortical bone thickness in the retromolar area. The inferior alveolar nerve canal was found to be located in the innermost site near the lower second molar area compared to other areas. In addition, the greatest thickness of the trabecular bone was found between the inferior alveolar nerve canal and the lateral cortical bone. Conclusions: In actual clinical settings involving bone harvesting in the posterior mandibular body, clinicians are advised to avoid locating the osteotomy line in the retromolar area to help protect the inferior alveolar nerve canal from damage. Harvesting the bone near the lower second molar area is judged to be the proper way of securing cortical bone with the greatest thickness.

• Journal of Dental Anesthesia and Pain Medicine
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• v.20 no.5
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• pp.313-323
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• 2020

Background: Previous studies have investigated the effects of dexamethasone injections into the pterygomandibular space and compared them to those of controls; however, the effects of dexamethasone injections before and after lower third molar surgery on postoperative complications have not been studied. This research investigated the postoperative sequelae of dexamethasone injections before and after surgery into the pterygomandibular space. The aim of this study was to evaluate the effects of preoperative and postoperative injections of 4 mg of dexamethasone into the pterygomandibular space on postoperative pain, facial swelling, and the restriction of mouth opening following lower third molar surgical removal. Methods: Twenty-seven participants with bilateral symmetrical lower impacted third molars were included in this study. Each participant was randomly allocated to one of two groups. Group A received injections of 1 ml dexamethasone (4 mg/mL) and 1 mL placebo into the pterygomandibular space before and after surgery, respectively. Group B received the same doses of placebo before surgery and dexamethasone after surgery. Results: A significant restriction of mouth opening on the second postoperative day was observed in both groups. Nonetheless, the postoperative restriction of mouth opening, facial swelling, postoperative pain, and analgesic consumption after lower third molar surgical removal were not significantly different in the two groups. Conclusions: Regardless of the time of administration, dexamethasone injections into the pterygomandibular space resulted in satisfactory control of the postoperative sequelae of the mandibular third molar surgical removal.

• The korean journal of orthodontics
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• v.23 no.3 s.42
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• pp.359-374
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• 1993

At present, many orthodontists regard the root parallelism of the posterior teeth important not only in diagnosis and treatment planning but also for predicting posttreatment stability. To evaluate it, they usually refer to the orthopantomogram. At this study, 97 samples were collected from students of Yonsei University, who have well-proportioned face, Angle's class I canine & molar relationships and no crown axis deviation of the posterior teeth including canines. Reliability of the root parallelism observed from orthopantomogram was evaluated by comparison with $45^{\circ}$ oblique cephalogram. The results were as follows : 1. In comparing the differences between anglular measurements in $45^{\circ}$ oblique cephalogram & orthopantomogram with $5^{\circ}$, those to mandibular plane were significantly less than to occlusal plane in number of items which showed less differences than $5^{\circ}$. 2. Compared the root parallelisms in the orthopantomogram with those in $45^{\circ}$ oblique cephalogram with $1\%$ significance level, parallelism between upper canine & 1st premolar, lower canine & 1st premolar, lower 1st premolar & 2nd premolar, and lower right 2nd molar & 3rd molar showed statistically significant differences. 3. When the significance between the differences of the root parallelism between above two kinds of film and $5^{\circ}$ was verified by two sided paired t-test, more or less large difference was shown between lower right 2nd molar & 3rd molar, a little larger than $5^{\circ}$ between lower canine & 1st premolar, smaller at the rest of them. 4. In $45^{\circ}$ oblique cephalogram, lower canine & 1st premolar showed convergent root arrangements each other, while in orthopantomogram they were divergent each other. All the others except them showed convergency on the upper, divergency on the lower in both films.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.20 no.3
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• pp.207-213
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• 1998

Purpose : This study attempted to relate the incidence of fractures at the mandibular angle with the presence and state of eruption of lower third molars, and to find out the real risk factors for angle fractures in the states of lower third molars. Materials and Methods : Medical records and radiographs of 395 patients with mandibular fractures were retrospectively reviewed. The presence and states of third molars were assessed for each patients and related to the occurrence of angle and other mandibular fractures. Results : Of 395 patients with mandibular fractures, 142 had angle fractures. The incidence of angle fractures was found to be significantly greater when partial erupted lower third molars were present and it had a definite role for risk factors for angle fractures. But there were no clear relationship between the incidence of angle fracrtures and states of without, fully erupted lower third molars. Furthermore, the states of patial and unerupted lower third molar had an effect on bony segment displacement. Conclusions : This study provides clinical evidence to suggest that patial erupted third molar teeth weaken the mandibular angle both quantitatively and qualitatively.

• The Journal of the Korean dental association
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• v.13 no.6
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• pp.559-562
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• 1975

This is a case of the patient, a 15 -year-old girl, presented a marked necrotic osteomyelitis due to misusage of the arsenic compound for devitaliaztion of the lower right 2nd molar in the right posterior part of the mandible. She was obtained good satisfactory results by sequestrectomy of necrotic bone and by removing of lower right 2nd molar and unerupted 3rd molar tooth germ.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.45 no.5
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• pp.233-240
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• 2019

Trigeminal nerve injury as a consequence of lower third molar surgery is a notorious complication and may affect the patient in long term. Inferior alveolar nerve (IAN) and lingual nerve (LN) injury result in different degree of neurosensory deficit and also other neurological symptoms. The long term effects may include persistent sensory loss, chronic pain and depression. It is crucial to understand the pathophysiology of the nerve injury from lower third molar surgery. Surgery remains the most promising treatment in moderate-to-severe nerve injuries. There are limitations in the current treatment methods and full recovery is not commonly achievable. It is better to prevent nerve injury than to treat with unpredictable results. Coronectomy has been proved to be effective in reducing IAN injury and carries minimal long-term morbidity. New technologies, like the roles of erythropoietin and stem cell therapy, are being investigated for neuroprotection and neural regeneration. Breakthroughs in basic and translational research are required to improve the clinical outcomes of the current treatment modalities of third molar surgery-related nerve injury.