• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.446-452
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• 1999

Ectopic eruption of the first permanent molar means the first permanent molar assumes an atypical path of eruption resulting in premature atypical resorption of the second primary molar. If the reversible eruption does not occur, early loss of the second primary molars results in space loss, mesial tipping of the first permanent molar, impaction of the second premolar, buccal segment crowding and overeruption of opposing tooth. The main objectives of treatment are (1) to prevent loss of the second deciduous molars so it can continue to serve as a space maintainer and (2) to regain lost arch length, allowing the second premolar to erupt into normal position. The optimal treatment approach depends on a number of factors including the clinical eruption status of /6/, the change in position of /6/, the amount of enamel ledge of /E/ entrapping /6/, the mobility of /E/, and the presence of pain or infection. Unilateral appliance to correct the mesial angulation of ectopic permanent first molars, as in the majority of the appliance designs, would produce a resultant force that would further enhance the space loss. A bilateral support similar to the holding arch design is recommended to maximize the anchorage. These case reports present the successful result of preserving space for the second premolar in treatment of ectopic eruption of the first permanent molar using Halterman appliance with bilateral anchorage on patients visiting department of pediatric dentistry in Samsung Medical Center.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.1
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• pp.95-103
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• 2022

The first permanent molars play a key role in maxillofacial development and occlusion. The purpose of this study is to investigate the characteristics and development stages of first molars with delayed eruption, and to evaluate their associations with congenital missing teeth. Eight-year-old patients who had delayed eruption in their first molars were classified into 75 patients with physical barriers and 77 patients without physical barriers. The development stages of the first and second molars in the delayed area were analyzed using Nolla method from the panoramic radiographs. The relationship between congenital missing teeth and delayed area was also investigated. Delayed eruption of first molars were more common in the maxilla alone. With the presence of physical barriers, male patients showed higher frequency in unilateral cases, while female patients had higher bilateral cases when there was no physical barrier. Delayed development of first molars were observed in delayed eruption area. In the absence of physical barriers, adjacent second molars were also developed slowly and the incidence of congenital missing teeth was high in delayed area. If first molars with delayed eruption are observed, clinical and radiographical follow-ups are necessary for the evaluation of their developmental stages and congenital missing teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.43 no.1
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• pp.51-59
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• 2016

The purpose of the present retrospective study was to analyze gender, age, awareness, etiology, and treatment choice in patients with failed eruption of the mandibular first molar. Radiographic material and dental records from 67 patients with 74 mandibular first molars with failed eruption treated during the years 2001-2014 were evaluated. As results, the prevalence of mandibular first molar with failed eruption was higher in males than females, and the average awareness age was 9.19 years old. The most common etiological cause was unknown, and the next most common causes were abnormal eruption pathway and odontogenic tumor in order. In this study, it is suggested that more dental education to children about the time of eruption of permanent tooth is required, and the importance of regular dental check-ups is emphasized during mixed dentition.

• 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.

• Journal of dental hygiene science
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• v.9 no.3
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• pp.257-263
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• 2009

The objective of this study is to establish the number of erupted $1^{st}$ molar, the age. sex and somatic measures of weight and height in population of Chungcheongnam-do, South Korea based cross sectional study. The consistent and complete data were obtained from 441 children with age of six. SPSS 12.0 was used for various statistical analyses including descriptive, cross tabulation, correlation and regression. Results demonstrates that variation of the number of the erupted $1^{st}$ molar was explained by age($x^2$(df)=117.68), height($x^2$(df=59.74) and weight($x^2$(df)=31.69) of children (P<.001). The study also showed the strong correlation among erupted $1^{st}$ molar rate, age, height and weight (p<.01). Numerical values of correlation among those are following: r = .45 between Erupted $1^{st}$ molar rate and age; r = .31 between erupted $1^{st}$ molar rate and height; r = .24 between erupted $1^{st}$ molar rate and weight; r = .40 between age and weight; r = .24 between age and height; r = .54 between height and weight. It was concluded that above variables influences one another and the age of the children is the greatest variable that influences the number of erupted $1^{st}$ molar, followed by height and weight of the children.

• 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.

• The korean journal of orthodontics
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• v.35 no.3 s.110
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• pp.227-237
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• 2005

Eruptive disturbance of the permanent lower first molar is an uncommon condition caused by physical barriers on the eruption path or failure of the eruptive mechanism. Once eruptive disturbance of the permanent lower first molar is diagnosed. treatment should be started as soon as possible to establish a normal eruption pathway and to avoid any detrimental effects on the developing occlusion A case of primary retention of the mandibular first permanent molar treated with operculectomy and forced eruption which showed good treatment results and stability is described

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.3
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• pp.325-336
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• 2009

The purpose of this study was to investigate the eruption pattern of the mandibular first molar in sagittal, frontal and horizontal views using the cone beam CT scanning. CT images were obtained from healthy 83 children (42 boys, 41 girls) between 3 to 10 years of age with a normal dentition according to Nolla stage. 1. In the frontal and horizontal view, the intermolar width decreased continuously with stage and slightly increased at the last stage. 2. In the sagittal and frontal view, eruption distances from occlusal plane were observed the largest change between stage 5 and 7. 3. In the horizontal and sagittal view, mandibular first molar from distal surface of primary second molar moved distally between stage 4 and 6. 4. In the sagittal view, angle from occlusal plane to mesio-distal axis increased between stage 4 and 8. 5. In the frontal view, angle from occlusal plane to bucco-lingual axis increased continuously during all stage. 6. In the horizontal view, angle from midsagittal plane to long axis increased between stage 5 and 8.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.598-604
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• 2004

Impaction of mandibular first molar is relatively rare and its overall frequency has been reported to be 0.01%. The etiology of impaction are lack of eruption space, physical obstacles such as supernumerary teeth, odontomas or odontogenic tumors, hereditary factors, functional disturbances of endocrine glands and traumas. Impaction of mandibular first molar can result in a short lower facial height, formation of a follicular cyst, pericoronal inflammation, resorption of the roots of neighboring teeth and malocclusion. The treatment options available for impacted teeth include surgical exposure, orthodontic forced eruption, surgical repositioning and surgical removal of unerupted molar. This report presents two cases of distally tilted and impacted mandibular first molars which were treated by surgical exposure. In these cases, we could observe spontaneous eruption of the impacted mandibular first molars after surgical exposure.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.2
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• pp.226-232
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• 2010

Incidence of tooth impaction varies from 5.6 to 18.8% of the population. Failure of eruption of the first and second permanent molars is rare; the prevalence in the normal population is 0.01% in case of the first permanent molar, and 0.06% in case of the second permanent molar. Permanent molars are particularly important for providing sufficient occlusal support and co-ordinating facial growth. Failure of eruption of permanent molars may result in various complications such as decrease in vertical dimension, posterior open bite, extrusion of antagonistic teeth, resorption and inclination of adjacent teeth, formation of cyst and so on. Treatment options of impacted teeth are periodic observation, surgical exposure, surgical exposure with subluxation, orthodontic relocation, and surgical extraction before prosthetic treatment. Early diagnosis and treatment are important, because delayed treatment induces various problems such as decreased spontaneous eruptive force, decreased successful percentage, increased treatment period, increased various complications. Prevalence of the failure of mandibular first molars is rare but eruptive guidance before extraction of impacted teeth is necessary due to importance of permanent molars. We reported two cases of surgical exposure of impacted mandibular first molar. In these cases, we could observe different result of the impacted mandibular first molar after surgical exposure.