• Journal of the korean academy of Pediatric Dentistry
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• v.48 no.2
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• pp.229-236
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• 2021

Eruption disturbances of the mandibular first molars can cause multiple problems in occlusal development although they are extremely rare. Early diagnosis and treatment are very important to prevent complications associated with eruption disturbances. The present case report describes the treatment of two cases of eruption disturbances of the mandibular first permanent molar. A fixed appliance composed of a cantilever spring with mandibular second deciduous molar as an anchor tooth was used to tract the impacted mandibular first permanent molar. The success of both cases shows that this novel traction appliance can be used to induce the eruption of an impacted mandibular first permanent molar within a short time in patients with intact mandibular second deciduous molar as an anchor tooth.

• Journal of the korean academy of Pediatric Dentistry
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• v.6 no.1
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• pp.53-63
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• 1979

To Study the eruption pattern of the mandibular second permanent molar, the author took 425 cases of Oblique Cephalogram from 6 to 13 years old children and observed the vertical and mesiodistal directional change and tooth axis change. The following results were obtained. : 1. The eruption pattern of the mandibular second permanent molar was changed at about 10.0~10.1 ages or calcification stage IX. 2. At the early stage, the path of eruption of the mandibular second parmanent molar directed upward and forward and after calcification stage IX it changed to the direction of upward. 3. At the early stage, the distance from the distal end of the mandibular first permanent molar to the anterior portion of the ascending ramus was 0.9~1.0 times larger than the mesio-distal diameter of the mandibular second molar, but at the later stage it was increased 1.4 times larger than the mesio-distal diameter of the mandibular second permanent molar.

• Journal of Korean society of Dental Hygiene
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• v.5 no.1
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• pp.29-38
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• 2005

In 2001, as a subject of this study, the first grade 165 kids in Yomju elementary school had been guided in pit and fissure sealant, fluoride rinse, group tooth brushing, and Dental health education as a part of oral disease preventive program. From the data, this author has estimated incremental dental health care program in school dental clinic in order to make it more effective and enlarge it. For that purpose, the program has been continued at six month intervals for two years. The retention condition of pit and fissure sealant in first molar and DMF rate had been investigated. The conclusions are as follows: 1. Full and partial retention of pit and fissure sealant was measured as 80.69% in maxillary right first molar, 83.20% in maxillary left first molar, and 86.72% in mandibular right first molar, and 86.28% in mandibular left first molar. 2. Retention of pit and fissure sealant in first molar was measured as 76.55% in maxillary right first molar, 81.03% in maxillary left first molar, 80.65% in mandibular left first molar, and 82.03% in mandibular right first molar. 3. Among Yomju elementary school students, DMF rate was measured as 8.7%, and DMFT index as 1.03. However, in Yangdong elementary school students the former was measured as 13.8% and the latter as 1.76. When the DMF rate difference between Yomju and Yangdong elementary school kids was considered, the oral health condition of the former was much better than that of the latter because the former had received incremental dental health care program for two years and on the other hand, the latter had not. So it is necessary that we should enlarge school dental clinic, improve and keep students' oral health.

• Restorative Dentistry and Endodontics
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• v.40 no.1
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• pp.75-78
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• 2015

Presented here is a case where 8 canals were located in a mandibular first molar. A patient with continuing pain in mandibular left first molar even after completion of biomechanical preparation was referred by a dentist. Following basic laws of the pulp chamber floor anatomy, 8 canals were located in three steps with 4 canals in each root. In both of the roots, 4 separate canals commenced which joined into two canals and exited as two separate foramina. At 6 mon follow-up visit, the tooth was found to be asymptomatic and revealed normal radiographic periapical area. The case stresses on the fact that understanding the laws of pulp chamber anatomy and complying with them while attempting to locate additional canals can prevent missing canals.

• Proceedings of the KACD Conference
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• 2001.11a
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• pp.574.1-574
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• 2001

Maxillary first molar, the "6-year molar", is the tooth largest in volume and most complex in root and root canal anatomy. Therefore, maxillary first molar is possibly the most treated, least understood. It is the posterior tooth with the highest endodontic failure rate and unquestionably one of the most important teeth. The earliest permanent posterior tooth to erupt, the mandibular first molar seems to be the most frequently in need of endodontic treatment.(omitted)

• The korean journal of orthodontics
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• v.25 no.3 s.50
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• pp.299-310
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• 1995

The purpose of this study is to know about the positional change of second molar when orthodontic treatment is performed. To know about it, we andlysed cephalogram pre. and post treatment for 54 adult patients who werefinished orthodontic treatment by banding to the first molar and classify them into 4 groups Class I extraction group 15, Class I nonextraction group 12, Class II group 13, class Class III group 14. The following conclusions were obtained : 1. In the extraction group of Class I , mandibular second molar showed less extrusion and mon distal inclination than first moarl. But maxillary second molar showed more or less extrusive and mesial inclination to much the same degree of first molar. 2. Inthe non-extractio group of Class I, mandibular second molar in intrusive to first molar, it showed smilar distal inclination to first molar. But maxillary second molar is extrusive similarly to first molar. 3. In the group of Class II , mandibular second molar is less extrusive than first molar and maxillary second molar is more extrusive than first molar. 4. In the group of Class III, mandibular second molar showed similar extrusion to first molar and more distal inclination than first molar. But maxillary second molar showed less extrusion than first molar. 5. A comparision of the positional change of second molar among groups : The change of distance from FH plane to funcation point of maxillary second molar is the difference between Class I extraction group and Class II group, Class I extraction group and Class III group. The change of maxillary second molar to palatal plane and occlusal plane is the difference between Class I extraction group and Class III group. And the change of distance from mandibular plan to furcation point of mandibular second molar is difference between Class I extraction group and non-extraction group, Class I non-extraction group and Class II group, Class I non-extraction group and Class III group. But the change of angle of mandibular second molar to mandibular plane and occlusal plane is make no difference in among groups.

• The korean journal of orthodontics
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• v.17 no.2
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• pp.311-320
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• 1987

The purpose of this study was to investigate the growth changes of maxilla and mandible and position changes of first permanent molars of growing children The author analyzed the data using cephalometric roentgenogram of 43 boys and 39 girls age of 6 to 11 with normal occlusion The obtained results were as follows 1 The eruption path of maxillary and mandibular first permanent molar superimposed on TM-ANS and mandibular plane shows individual variation 2 There was no correlation between horizontal and vertical changes of maxillary first permanent molar, but positive correlation in mandibular first permanent molar 3 As the eruption, the forward changes of mandibular first permanent molar was significantly greater than that of maxillary first permanent molar 4 As the ages were increased, there were irregular growth changes of maxilla and mandible 5 Growth changes of lower anterior facial height was relatively stable 6 N-S-${\bar{6}}$ was stable after age 7.

• The Journal of the Korean dental association
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• v.41 no.5 s.408
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• pp.359-361
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• 2003

A cases report is presented describing treatment : of a mandibular first molar in which three canals were located, prepared, and obtained in the mesial root. The incidence of middle mesial canals in mandibular molars is reviewed 물 treatment considerations are described.

• Journal of Veterinary Clinics
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• v.36 no.2
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• pp.106-108
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• 2019

This clinical report describes hemisection and endodontic treatment of first molar tooth and mandible fracture repair in a dog. A 10 years old spayed female shih-tzu was diagnosed as left mandibular fracture by oral examination and dental radiography. First, partial odontectomy of mesial root of mandibular first molar placed in fracture line was performed, and then endodontic treatment of distal root and bone graft in extraction site was performed. Thereafter the fracture region was fixed with interdental wiring and acryl resin splint. Mandibular fracture site was healed without any complications, observed for 19 weeks follow-up period. Upon this result, this case is proving that fractured mandible can be treated successfully with hemisection followed by bone graft, interdental wiring and acryl resin splint to preserve the remaining tooth for mastication rather than tooth extraction.

• Journal of the korean academy of Pediatric Dentistry
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• v.47 no.2
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• pp.219-227
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• 2020

Tooth eruption involves a complex developmental process of tooth migration from the dental follicular origin to the final occlusion position in the oral cavity via the alveolar process. Disturbance of tooth eruption can occur at any point in a series of eruption stages; however, horizontal impaction of the mandibular first molar and primary retention of the primary mandibular second molar are rarely observed simultaneously. This study describes the treatment for two cases of horizontally impacted first molar with primary retention of primary molar. The primary retention of the primary mandibular second molar was extracted, and orthodontic traction was applied to the horizontally impacted primary mandibular first molar. Subsequently, displacement of the premolar tooth bud was improved and space regaining for eruption was achieved, guiding to normal eruption of the first molar.