• Maxillofacial Plastic and Reconstructive Surgery
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• 제20권3호
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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.

• 치과방사선
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• 제3권1호
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• pp.7-18
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• 1973

The authors have taken the x-ray films of carpal bone and orthopantomographs in Korean children to research the degree of ossification of carpal bone, that of calcification of tooth in jaw bone, the eruption rate of tooth, and the completion rate of apical foramen, and have compared the bone age and tooth age. We have gained a series of intersting conclusions to dare to report. 1. The ossification of carpal bone and the growth of tooth had processed proportionally to each other. 2. Both the bone age and tooth age were earlier in the female than in the male. 3. The completion of tooth crown formation and that of tooth root formation had processed proportionally to each other, and the general tendency of process was the earliest in the mandibular first molar and the latest in the second molar. 4. The eruption of tooth was the earliest in the mandibular first molar. The other teeth had erupted in the following orders: the central incisor, the lateral incisor, the first premolar, the second premolar, the canine and the second molar.

• 대한치과교정학회지
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• 제23권1호
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• pp.123-136
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• 1993

The purpose of this report is to present the successful improvement of occlusal relationship and facial esthetics in class II division 1 malocclusion with severe labioversion of upper anterior teeth and severe overjet, and in class II malocclusion with infraversion of bilateral maxillary canines by MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, with upper second molar extraction. After treatment, there were natural contact points at canine and premolar regions, normal occlusal relation-ship and treatment results, satisfied the gnathologic concept, in this 2 cases. Compared with the routine treatment with premolar extraction, the treatment time and patients' discomfort were reduced. And the MEAW mechanics, which enables us to get effective distal on mass movement of maxillary dentition, resulted in reduction of the treatment time and getting the good treatment results. Consequently, the majot concerns in orthodontic treatment are appropriate diagnosis and treatment plan, so, the application of second molar extraction with appropriate case analysis and diagnosis is very helpful to orthodontic treatment.

• 대한장애인치과학회지
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• 제12권2호
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• pp.45-49
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• 2016

This study investigates the success rate of pulpotomy using electrosurgery operated on a primary molar in caries. The pulpotomy using electrosurgery was done on 253 primary molars of 111 young patients from 2 to 9 years old during the period of the first day of January 2011 to the last day of December 2015. After the amputation of pulp and hemostasis of primary molar were done using electrosurgery, MTA as pulp capping material was applied to the primary molar and the tooth was restored with the stainless steel crown. The follow up period after the treatment ranged from 4-46 months. The clinical and radiographic success rate ranged from 92.1 - 94.3%. Which is comparable to formocresol and ferric sulfate pulpotomy. Due to its non-pharmacological characteristic, electrosurgery can minimize harmful effect on the pulp tissue. Its fast bleeding control makes it easy and safe to use in pediatric and disabled patients in comparatively simple manner. Electrosurgery can be an alternative for pulp therapy considering the side effects of pharmacological ways.

• Journal of Oral Medicine and Pain
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• 제44권1호
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• pp.40-44
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• 2019

Third molar extraction, one of the important surgical treatments commonly practiced in dentistry, presents various symptoms after surgery ranging from temporary or mild symptoms to permanent or severe complications. However, oral burning pain, dysesthesia, parageusia, dry mouth, headache and pain in multiple teeth are not the common symptoms that patients often complain after dental extraction. Here, the authors report two cases who presented acute neuropathic symptoms mentioned above in the orofacial regions following third molar extraction. At the initial examination, the healing of the tooth sockets of two patients was normal. One patient was diagnosed as megaloblastic anemia associated with Vitamin $B_{12}$ deficiency and was referred to the Department of Hematology for assessing the underlying etiology of anemia. The laboratory test for the other patient revealed microcytic anemia related to iron deficiency. The patient with iron deficiency anemia was successfully treated with iron supplement. These two cases suggest that anemia, as an underlying systemic disease, may be a rare etiology explaining acute onset of peripheral neuropathy in the orofacial regions after third molar extraction and should be considered in the assessment of patients who report neuropathic symptoms after dental extraction.

• Journal of Dental Anesthesia and Pain Medicine
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• 제21권6호
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• pp.575-582
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• 2021

Background: The aim of this randomized, triple-blind trial was to determine the anesthetic, analgesic, and hemodynamic effects of articaine and bupivacaine in the extraction of impacted mandibular third molar teeth. Methods: Twenty-six patients who underwent removal of bilaterally symmetric mandibular third molars were randomly assigned to articaine and bupivacaine groups in a split-mouth design. The onset of anesthetic action, intraoperative comfort, total amount of solution used, duration of postoperative anesthesia and analgesia, rescue analgesic use, postoperative pain, intraoperative bleeding, and hemodynamic parameters were evaluated. Results: In the articaine group, the onset of anesthetic activity was faster, intraoperative comfort was greater, and effective anesthesia required less local anesthetic solution. The bupivacaine group showed a significantly longer duration of postoperative anesthesia and analgesia, in addition to lower visual analog scale values at 6 and 48 hours postoperatively. There were no significant differences between the two solutions regarding rescue analgesic medication use, intraoperative bleeding, or hemodynamics. Conclusion: Articaine showed greater clinical efficacy than bupivacaine in intraoperative anesthesia, achieving faster onset of anesthetic action and greater patient comfort while also requiring less reinforcement during surgery. However, bupivacaine was superior in terms of postoperative anesthesia, reducing postoperative pain due to its residual anesthetic and analgesic effects. Both anesthetic solutions led to similar hemodynamics at low doses in mandibular third molar surgery

• 대한치과보철학회지
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• 제46권5호
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• pp.479-489
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• 2008

목적: 상악 구치부에서 자연치와 임플란트 보철시, 보철치관/고정체 비율에 따른 응력분포 양상을 비교하고자 했다. 재료 및 방법: 자연치 모델의 경우는 획득한 3차원 인체모델을 상악 좌측 제2소구치 및 제 1대구치가 포함된 상악골을 Box 형태의 3차원 유한요소모델로 변환하였고, 임플란트 모델은 3차원 인체모델에서 치아 부분을 제거하고 동일 부위에 임플란트 모델을 연결하는 과정을 거쳐서 임플란트가 삽입된 유한요소모델을 구성하였다. 치관/고정체 비율을 0.7:1, 1:1, 1.25:1이 되도록 골수준 (bone level)을 조정하였으며 각 모델의 치관 부위에 300 N의 수직 하중과 수평하중을 각각 가했다. 결과: 1. 모든 하중 조건하에서 자연치와 임플란트 모두에서 피질골과 인접하는 경부에 응력이 집중되는 양상을 보였다. 2. 치관/치근 (고정체) 비가 증가함에 따라 자연치와 임플란트 모두에서 교합면에 수직적 하중을 가한 경우에는 응력의 변화가 뚜렷하지 않았으나, 수평적 하중을 가한 경우에서는 응력이 증가하는 양상을 보였다. 3. 자연치의 경우에 치관/치근비가 증가함에 따라 splinting이 응력감소 효과를 보였고, 임플란트의 경우에는, 치관/고정체 비가 증가함에 따라 splinting이 수직 하중조건에 응력감소효과를 보였으나, 중심에서 벗어난 하중조건에는 최대응력이 오히려 증가하는 양상을 보였다. 4. 임플란트의 경우, 치관/고정체 비가 증가함에 따라 splinting이 수평하중조건 4에서 뚜렷한 응력감소 효과를 보이나, 수평 하중조건 5에서는 응력감소 효과가 감소되고, 특히 치관/고정체 비가 1.25:1인 경우에서는 오히려 응력의 증가를 보였다. 결론: 임플란트 보철물은 치관/고정체 비가 커질수록 더 큰 응력을 받게 되고, splinting의 효과도 감소하게 된다. 또한 교합하중이 임플란트의 장축을 벗어나거나 중심에서 벗어난 경우 응력이 커지는 것으로 사료된다.

• Journal of Korean Dental Science
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• 제3권1호
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• pp.5-10
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• 2010

This study sought to compare the amounts of posterior anchorage loss during the en masse retraction of the upper anterior teeth between orthodontic mini-implant (OMI) and conventional anchorage reinforcement (CAR) such as headgear and/or transpalatal arch. The subjects were 52 adult female patients treated with sliding mechanics (MBT brackets, .022" slot, .019X.025" stainless steel wire, 3M-Unitek, Monrovia, CA, USA). They were allocated into Group 1 (N=24, Class I malocclusion (CI), upper and lower first premolar (UP1LP1) extraction, and CAR), Group 2 (N=15, Cl, UP1LP1 extraction and OMI), and Group 3 (N=13, Class II division 1 malocclusion, upper first and lower second premolar extraction, and OMI). Lateral cephalograms were taken before (T0) and after treatment (T1). A total of 11 anchorage variables were measured. Analysis of variance was used for statistical analysis. There was no significant difference in treatment duration and anchorage variables at T0 among the three groups. Groups 2 and 3 showed significantly larger retraction of the upper incisor edge (U1E-sag, 9.3mm:7.3mm, P<.05) and less posterior anchorage loss (U6M-sag, 0.7~0.9mm:2mm, P<.05; U6A-sag, 0.5mm:2mm, P<.01) than Group 1. The ratio of retraction amount of the upper incisor edge per 1 of anchorage loss in the upper molar made for the significant difference between Groups 1 and 2 (4.6mm:7.0mm, P<.05). Group 3 showed a relatively distal inclination of the upper molar (P<.05) and the intrusion of the upper incisor and first molar (U1E-ver, P<.05; U6F-ver, P<.05) compared to Groups 1 and 2. Although OMI could not shorten the treatment duration, it could provide better maximum posterior anchorage than CAR.

• 대한치과교정학회지
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• 제19권1호
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• pp.21-44
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• 1989

Incipient changes of the periodontal tissue in the pressure zones of rat molar subjected to the experimental force were studied by the transmission electron microscope. Experimental animals were consisted in 3 control and 21 experimental rats, of which one maxillary first molar was moved buccally with a fixed appliance which were exerting the force of 15 gm. After experimental period of 1 hour, 3 hours, 6 hours, 24 hours, 2 days, 3 days and 7 days, the animal were sacrificed with cardiac perfusion of $2.5\%$ glutaraldehyde in the sodium cacodylate buffer and the experimental teeth with surrounding periodontal structures were processed for electron microscope. At the beginning of the tooth movement, periodontal ligaments of the pressure were compressed and collagenous fibers were arranged parallel to the root of the teeth and cell free zones in company with cell necrosis were followed. Cell free zones at the periodontal ligaments appeared in the 3 hour survival group, and getting severe with time lapse it became widespread in 2-3 day survival group and undermining bone resorption as a healing process was observed in 7 day survival group. Dilatation of mitochondria and swelling of the rER in the fibroblast and other connective tissue cells in the periodontal ligament were observed in the 3 hour survival group, which were characteristics of the incipient changes in the compressed periodontal ligament. Dilatation of nuclear membrane and pyknosis were followed by the destruction of the nucleus and cell membrane. There were no evidence in cell damage or necrosis of the alveolar bone adjacent to the hyalinized area of periodontal ligaments.

• 치과방사선
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• 제17권1호
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• pp.209-222
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• 1987

The author invested the gonial angle, the angle of mandibular and mental canal to the lower border of the mandible, and a relationship of the position of the mandibular canal to the root apex of the posterior teeth and the cortical plate of the lower of the mandible. The materials consisted of 458 pantomograms in male and female aged 11-40 and divided into 5 groups at 5 year intervals and subdivided into 3 groups by gonial angle. The results were as follows; 1. The gonial angle decreased with age, but slight increase occurred over 26-30 years. 2. The average angle of the mandibular canal to the lower border of the mandible was 151.6° and did not correlate with age. 3. The average angle of the mental canal to the lower border of the mandible was 36.9° and didn't correlate with age. 4. The angles of mandibular and mental canal to the lower border of the mandible correlated with gonial angle. 5. The distance from the root apex of the posterior teeth to the upper wall of the mandibular canal was most short at the region of the distal root of the mandibular second molar and increased with age at the region of the mandibular second molar. 6. The distance from the lower wall of the mandibular canal to the cortical plate of the lower border of the mandible was most short at the region of the mesial root of the mandibular first molar and didn't correlate with age.