• 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.

• The Journal of the Korean dental association
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• v.55 no.5
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• pp.328-338
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• 2017

Introduction: The aim of the current study was to describe the prevalence and treatment of mandibular first molar eruption disturbances. Methods: A total of 38 mandibular first molars(M1mn) from 36 patients(17 males and 19 females; aged 9 years 2 months?35 years 10 months) were identified from the 13,391 patients that received orthodontic treatment from 1983?2012. The subjects were classified into 3 categories based on panoramic radiographic examination: impaction due to ectopic position of the tooth germ relative to the contra-side same tooth(Group 1), impaction due to obstruction of the eruption path with cyst or calcium mass (Group 2), and primary and secondary retention due to defects in the follicle or periodontal ligament(PDL; Group 3). The treatment outcomes were evaluated into four categories: no treatment(A), orthodontic traction(B), autotransplantation(C), and extraction due to orthodontic traction failure(D). Results: The prevalence rate of M1mn eruption disturbances in this sample was 0.27%. In Groups 1 and 2, most of the impacted M1mn were erupted successfully by orthodontic traction. In Group 3, most of the retained M1mn were failed to erupt and recommended for extraction. Conclusions: Treatment prognosis was favorable on Group 1 & 2 than Group 3. After removing an element of the cause in case of Group 1 & 2, orthodontic traction or periodic observation will be recommended.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.4
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• pp.469-482
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• 2023

This study aimed to investigate the treatment options for the delayed eruption of mandibular premolars and identify the predictors of spontaneous eruption using panoramic radiography. The prevalence of delayed mandibular premolar eruption in this retrospective analysis, comprising 254 patients (aged 9 - 15 years), was 5.19%, with no significant difference based on gender. The mandibular second premolars were most affected (4.39%) compared to the first premolars (0.76%). No significant difference in prevalence was observed between the left and right sides. Among the treated mandibular premolars, primary molar-related lesions were identified as the leading cause (7.85%) of delayed tooth eruption. The treatment duration varied based on the Nolla stage, eruption stage, and treatment method. Teeth with Nolla stage 7 or lower had a treatment duration of 22.89 ± 11.96 months, whereas those with stage 8 or higher had a 15.02 ± 6.34 month duration. The deeper the tooth was located in the bone, the longer the treatment period became. The treatment duration varied depending on the treatment method, and statistically, there was no significant difference. The treatment durations for affected mandibular premolars increased with the depth of impaction angle of inclination. In this study, the treatment duration for delayed eruptions varied depending on the Nolla stage, eruption stage, and treatment method. Variations in the impaction depth and inclination angle across various treatment approaches, as explored in this study, might offer valuable insights into the selection of the most suitable management options for delayed tooth eruptions.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.1
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• pp.151-158
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• 2008

Upper and lower cuspids are very important teeth in point of function as well as esthetic. However, failure of eruption of the canine sometimes happens and is frequently encountered clinical problems. Upper cuspids are more frequently impacted as compared with lower cuspis and palatally impaction is more frequent event than labially impaction. Impaction of the mandibular canine is unusual event, especially crossing the midline (transmigration) is very rare. Because of, in most cases, there is no signs and symptoms, impacted teeth can be detected by periodic radiograph examination. The etiology of impaction is unclear and multifactorial. The treatment of impacted canine is influenced by presence of obstacles, location and direction of impaction, space for alignment and development of root. There are several treatment options; (1) Surgical removal and/or observation, (2) Window opening and orthodontic traction, (3) Autotransplantation. The first patient (impaction of upper right cuspid) is treated with window opening and orthodontic traction. The second patient (bilaterally impaction of lower cuspids) is treated with autotransplantation, because of transmigration.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.2
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• pp.322-328
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• 2007

The first molar is important for mastication and also it plays roles to formation of vertical occlusion and growth of jaw bone after mixed dentition. 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 options of treatment plans are as follows; observation, surgical exposure, orthodontic traction, surgical relocation and extraction. Surgical exposure could be considered as a basic treatment plan. For surgical exposure it is important to maintain patent channel between the crown and the normal eruptive path into the oral cavity, many techniques including cementation of a celluloid crown, packing with zinc oxide-eugenol surgical pack are used. In these cases, we could observe spontaneous eruption of mandibular first molar using surgical exposure with or without removal of odontoma. Also we could obtain the main patency effectively and conveniently by using surgical pack and translucent retainer.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.1
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• pp.41-45
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• 2004

In the normal growth and development of the mandible, the molar tooth buds distal to the first permanent molar have a mesial inclination. This inclination is usually self-correcting, but, unfortunately, this self-correction does not always occur. The first case is about, 14-year-old female patient with familial history of lower second molar impaction. Her lower second molars were both impacted, and she was treated with sectional wires and open-coil springs. The second case, 14-year-old male, we treated his impacted #47 with Halterman appliance. The third case, 11-year-old male, his both mandibular second molars were impacted during full-fixed orthodontic treatment. They were treated with brass wire, sectional wire and open-coil spring.

• The Journal of the Korean dental association
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• v.47 no.11
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• pp.750-757
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• 2009

Purpose : The purpose of this study is to evaluate the clinical availability of submentoplasty for esthethic improvement of the cervico-facial region of patients with obtuse chin-neck angle. Materials and methods : Case 1. We evaluate the changes of submental line length and chin-neck angle of 35-year-old woman with skeletal Class III and mandibular excess with excessive submental fat before and after surgery: Bilateral sagittal split ramus osteotomy(BSSRO) setback(5mm), Mandibular Angle Reduction, Reduction Malarplasty and Submentoplasty. In this case, It was done simultaneously with orthognathic surgery. Case 2. The changes of submental line length and chin-neck angle of 20-year-old man with skeletal class III and maxillary defiency were evaluated before surgery, at first surgery : Lefort I osteotomy(6mm posterior Impaction), BSSRO setback(9mm), Paranasal Augmentation and at second surgery: genioplasty(6mm advanced) with submentoplasty. In this case, submentoplasty and advancement genioplasty were done after 2 months post-operative periods. Results : Case 1. In case of the Skeletal Class III mandibular excess with submental fat deposit, It showed the improvement of submental angle and length of submental line after simultaneous submentoplasty. Submental angle is changed from $177^{\circ}$ (pre-op) to $151^{\circ}$ (post-op) and submental line length is changed from 8mm(pre-op) to 36mm(post-op). Case 2. The improvement of submental angle and length of submental line after delayed submentoplasty was aquired in case of the skeletal class III maxillary defiency. Submental angle is changed from $154^{\circ}$ (pre-op) to $161^{\circ}$ (first surgery) and to $153^{\circ}$ (second surgery) and submental line length is changed from 25mm(pre-op) to 19mm(first surgery) and to 23mm(second surgery). Conclusion : The results suggest that Submentoplasty is useful surgical procedure for esthethic improvement of the cervicofacial region of patients with obtuse chin-neck angle.

• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.4
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• pp.464-473
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• 2018

The purpose of this study was to investigate the distribution of eruption disturbance and to analyze its causes, treatment methods, and duration of orthodontic traction, based on 703 patients with eruption disturbance who were treated in the pediatric dental clinic of Seoul National University Dental Hospital between July 2011 and June 2016. Eruption disturbance in pediatric patients was most prevalent in the maxillary canine, followed by the maxillary central incisor and maxillary first molar. Eruption disorder of the maxillary canine was more common in females (p < 0.001), whereas the maxillary central incisor (p = 0.009), maxillary first molar (p < 0.001) and mandibular first molar (p = 0.028) were more common in males than females. The most common causes of eruption disturbance were abnormality of the eruption pathway and the presence of obstacles in the pathway. Orthodontic traction was the most prevalent treatment choice for eruption disorder, mostly done for the maxillary central incisors. The duration of orthodontic traction was shorter with younger age (p < 0.001) and lower crown position (p < 0.001). It is important for pediatric patients to detect eruption disorders early through regular checkup, and it is necessary to initiate treatment at an appropriate time with an accurate diagnosis and treatment plan.