• Title/Summary/Keyword: 제2 대구치 발거

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Effect of the lower third molar on the treatment of Class III malocclusion (하악 제3대구치 발거 시기가 III급 부정교합의 치료에 미치는 영향)

  • Son, Myung-Ho;Chang, Young-Il
    • The korean journal of orthodontics
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    • v.34 no.5 s.106
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    • pp.394-407
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    • 2004
  • The Purpose of this study was to evaluate the effect of the lower third molar on treatment time and distal en masse movement of the lower dentition in Giass III malocclusions. Thirty subjects (9 males and 27 females) were selected, all of whom were diagnosed as Glass III malocclusion and treated by fixed appliances without premolar and/or molar extraction. They were divided into three groups Group 1 consisted of 12 subjects. whose lower third molars were not extracted during the whole orthodontic treatment. Group 2 consisted of 8 subjects. whose lower third molars were extracted after WEAW application and before removal of the orthodontic appliances. Group 3 consisted of 10 subjects whose lower third molars were extracted before MEAW application. For each subject. overall treatment time and duration of MEAW application were determined. In addition. pre-treatment and post-treatment lateral cephalometric radiographs were analyzed. All data were Processed statistically with ANOVA, and the conclusions were as follows: There was no significant difference among the groups in overall treatment time However, duration of MEAW application was longer in Group 2 than in Group 1 or Group 3. The overjet that was established after orthodontic treatment was largest in Group 3, in which the lower third molars were extracted befor MEAW application. After orthodontic treatment, IMPA decreased in Group 3. but increased in Group 1 and Group 2. There was no significant difference among the three groups in the translation of lower second molars However the tipping movement of lower second molars was significantly different, highest in Group 2 and lowest in Group 1 Therefore. it is thought to be better for the orthodontic treatment of Class III malocclusions to extract the lower third molars before MEAW application. In Group 2, the mandibular plane angle was decreased as a result of forward rotation of the mandible This skeletal change was thought to bring about the difficulty of treatment.

The Prevalence of Enamel Projection on Molar Teeth Extracted from Dental Patients (치과 환자로부터 발거된 치아에서의 법랑돌기의 발현빈도)

  • Bae, Sung-Suk;Ku, Young
    • Journal of dental hygiene science
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    • v.7 no.4
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    • pp.207-211
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    • 2007
  • Many studies reported that the presence of cervical enamel projection (CEP) in cemento-enamel junction(CEJ) is greatly related to periodontal disease. The aim of this study was to investigate the prevalence of enamel projections in buccal, mesial, distal and lingual(palatal) surface of maxillary and mandibular first and second molars on extracted teeth. Among 660 teeth extracted due to the periodontal disease and dental caries in Seoul National University Dental Hospital was examined, 530 teeth which has distinct CEJ were examined with 8 times x electronic magnifier by one examiner. The prevalence of CEP for maxillary teeth (45.49%) was higher than that of mandible (39.62%). The first molar (45.22%) had more CEP than second (39.89%). Furthermore, buccal surface had highest incidence of CEP than other surfaces. The results of this study imply that the clinicians should take good care of the prevalence of CEP when scaling or root planning, plaque control instruction and periodontal surgery.

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A study on treatment effects of Class III cases by second molar extraction (제 2 대구치 발거에 의한 III급 부정교합자의 치료효과에 관한 연구)

  • Lee, Sung-Hee;Park, Young-Guk;Chung, Kyu-Rhim
    • 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

매복 하악 제3대구치의 발거에 대하여

  • Ryu, Dong-Mok
    • The Journal of the Korean dental association
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    • v.26 no.10 s.233
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    • pp.898-902
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    • 1988
  • 완전히 발육된 하악 제3대구치가 매복되어 있거나 또는 부분적으로 맹출된 상태일때는 임상증상을 일으키기 전에 발치하는 것이 치관주위염이나 이로 인한 합병증 및 치주질환 등을 예방할 수 있느느 가장 좋은 방법이며 이미 임상 증상을 유발한 매복 하악 제 3대구치는 대부분 재발방지를 위하여 발거하게 된다. 성공적인 발치의 기준을 1) 치아의 완전한 발치 2) 인접조직에 대한 최소한의 외과적 손상 3) 술후 합병증의 극소화 4) 가능한한 시술 시간의 단축 등이라 할때 매복 하악제 3대구치의 성공적인 발거를 위하여는 발치의 기본 원칙을 숙지하여야 함은 물론이며 더욱 면밀한 술전 평가와 외과적 발치술 시 필요한 기구의 완비 등이 필수적이라 할 것이다.

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Reasons for Extraction of Permanent Teeth in Private Dental Clinics (치과의원 내원환자의 영구치 발거원인에 관한 조사연구)

  • Lee, Byung-Ho
    • Journal of dental hygiene science
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    • v.8 no.1
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    • pp.1-6
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    • 2008
  • The purpose of this study was to analyze the reasons and mean age for tooth extraction among patients living in Busan city. The researcher observed 1,119 patients' teeth extracted due to dental caries, periodontal disease and other reasons. This study examined the reasons for tooth extraction by age, sex, and tooth-kind. The reasons for tooth extraction were dental caries, periodontal disease, eruption problems and others. The obtained results were as follows; 1. Among the reasons for tooth extraction, dental caries accounted for 25.9%, periodontal disease 56.5%. 2. Periodontal disease was the main reason for tooth extraction and continued throughout life irrespective of sex. However dental caries was remarkably increasing in those aged 30 years old and under. 3. In the extraction of permanent teeth, males outnumbered females while upper teeth did lower teeth. 4. Although the third molars were most extracted in all kinds of teeth, the main reasons for the extraction were eruption problem. 5. The mean age of the tooth extracted was 47.9 years in both sexes for the mandibular first molars and the mandibular first molars had the shortest life except third molars of total teeth. The mandibular canines had the longest life of total teeth. Because dental caries and periodontal disease are the main causes of tooth extraction in Korea, the dental health policy should be focused on the prevention and treatment of these two diseases in the government level.

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Pretreatment characteristics of adolescents with Class II malocclusion treated by maxillary second molar extraction (상악 제2대구치를 발거하고 치료한 성장기 II급 부정교합 환자의 치료전 특성)

  • Kim, Jae-Hyung;Kim, Joeng-Il;Lim, Yong-Kyu;Lee, Dong-Yul
    • The korean journal of orthodontics
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    • v.35 no.3 s.110
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    • pp.182-195
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    • 2005
  • The purpose of this retrospective study was to estimate the pretreatment characteristics of growing patients with Class II malocclusion. who had been treated with maxillary second molar extractions The sample comprised of 51 subjects; 18 subjects were classified into the molar extraction group, and 33 subjects were treated without extraction and classified into the nonextraction group. Pretreatment lateral cephalograms were calculated and analyzed by independent t-test and stepwise discriminant analysis. In measurements for skeletal pattern, no anteroposterior measurements and proportions of various vertical dimensions were significantly different. and only some measurements such as $AB-MP(^{\circ)$, Na-We(mm), AVD (mm) were significantly different between the two treatment groups (p<0.05). In measurements for dentoalveolar pattern. some measurements, which were related to the position and angulation of the upper and lower permanent first molars, and the angulation of the upper third molars, were significantly different between the two treatment groups In particular, the maxillary second molar extraction group exhibited more mesial angulation of maxillary first molar to the occlusal plane.

A STUDY ON THE PRE-ERUPTIVE POSITIONAL CHANCE OF THE LOWER THIRD MOLAR FOLLOWING ORTHODONTIC TREATMENT (교정치료에 따른 미맹출 하악 제3대구치의 위치 변화에 관한 연구)

  • Lee, Kyoung-Won;Bae, Seong-Ryol;Kim, Sang-Cheol
    • The korean journal of orthodontics
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    • v.26 no.1 s.54
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    • pp.105-111
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    • 1996
  • Most of orthodontic cases are treated with extraction of certain teeth, which influence the pre-eruptive movement of the lower third molar The purpose of this study was to evaluate the positional change of lower third molar following orthodontic treatment. Pre- and post-treatment pantomograms of 163 orthodontic patients (77 nonextraction group, 78 first premolar- extraction group, 8 second molar- extraction group) were analyzed in terms of the mesiodistal and buccolingual angles of lower third molar. The results were as follows. 1. The change of the mesiodistal angle of lower third molar by orthodontic treatment was significant in second molar-extraction group. 2. The mesiodistal angle of lower third molar in pre-treatment was significantly correlated to the mesiodistal angle in post-treatment and/or the change of the mesiodistal angle by treatment. 3. The change of the buccolingual angle of lower third molar by orthodontic treatment was significant in non -extraction group or first premolar-extrction group. 4. The change of the buccolingual angle of lower third molar by treatment was significantly correlated to the mesiodistal angle in post-treatment, the change of the mesiodistal angle by treatment, the buccolingual angle in pre-treatment or the buccolingual angle in post-treatment.

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Micromorphological Analysis of Primary Second Molar with Molar-incisor Malformation : A Case Report (Molar-incisor malformation에 이환된 제2유구치의 미세 형태학적 분석 : 증례 보고)

  • Kim, Myunghwan;Park, Howon;Lee, Juhyun;Seo, Hyunwoo
    • Journal of the korean academy of Pediatric Dentistry
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    • v.48 no.3
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    • pp.352-358
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    • 2021
  • Molar-incisor malformation (MIM) is characterized by malformation in the root with a normal crown. While MIM mostly occurs in the permanent first molar, it has also been reported in the maxillary central incisor and the primary second molar (PSM), but anatomical analysis of the primary teeth with MIM has not been studied to date. In this case report, a patient with MIM was reported, and an extracted PSM with MIM was analyzed with micro computed tomography (CT). A cervical constriction morphology of the cementoenamel junction (CEJ) can be observed in extracted PSM. In micro CT analysis, characteristics such a mineralized plate (cervical mineralized diaphragm) in the CEJ area, complex root canal morphologies, a calcified mass inside the pulp chamber, and constricted pulp chamber of crown portion were observed.

ERUPTION GUIDANCE OF IMPACTED SECOND PREMOLAR TOOTH BY EXTRACTION OF PROLONGED RETAINED SECOND PRIMARY MOLAR. (만기 잔존된 제 2 유구치 발거에 의한 제 2 소구치의 자발적 맹출 유도)

  • Lee, Keun-Hye;Nam, Dong-Woo;Kim, Hyun-Jung;Kim, Young-Jin;Nam, Soon-Hyeun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.30 no.3
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    • pp.495-501
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    • 2003
  • Impaction is defined as the cessation of the eruption of the tooth caused by a clinically or radiographically detectable physical barrier in the eruption path or by the ectopic position of tooth germ. Besides the third molars and the maxillary canines, the most common impacted tooth is the second premolar. The overall frequency of premolar impaction has been reported to be 0.5%. In some cases, orthodontic traction and surgical repositioning may be indicated. When impacted second premolar is involved with prolonged retained second primary molar, extraction of primary molar and space maintenance lead to eruption of second premolar. In these cases, all patients visited to department of pediatric dentistry of Kyungpook National University Hospital for the chief complaint of unerupted second premolar. Extraction of prolonged retained second primary molar and space management are tried for spontaneous eruption of impacted second premolar tooth. The results were as follows: 1. When impacted second premolar is involved with prolonged retained second primary molar, minimal treatment via elimination of primary molar leads to successful results. 2. Proper space management and periodic radiographic examination are required before eruption of second premolar. 3. Sufficient time must be allowed for confirm of tooth movement before orthodontic traction or surgical repositioning. 4. The result is more successful in incomplete root development.

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Eruption Guidance of Distally Displaced Mandibular Second Premolar by the Hemisection of Primary Second Molar: Two Case Reports (선행 유치의 편측치아절제술에 의한 원심으로 변위된 하악 제2소구치의 맹출 유도)

  • Yongwook, Shin;Howon, Park;Juhyun, Lee
    • Journal of the korean academy of Pediatric Dentistry
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    • v.49 no.3
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    • pp.340-347
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    • 2022
  • Distal displacement of the tooth germ of the mandibular second premolar (MnP2) leads to its impaction and obturation of the eruption path of the mandibular first molar delaying its eruption. The present case report describes the treatment of 2 cases of eruption guidance for distally displaced developing MnP2 that caused delayed eruption of the mandibular first molar. Intentional extraction of primary predecessor results in the mesial shift of the displaced MnP2. However, unfavorable distal ectopic eruption of the mandibular first premolar after the premature loss of primary second molar has been previously reported. Hemisection and sequential extraction of the mandibular primary second molar were performed to mesially shift the distally displaced MnP2, while preventing unfavorable distal ectopic eruption of the mandibular first premolar.