• Journal of the korean academy of Pediatric Dentistry
• /
• v.42 no.3
• /
• pp.257-263
• /
• 2015

Impacted teeth occur at higher frequencies in permanent than primary dentition. The most frequently affected teeth are the maxillary and mandibular third molars, whereas it is quite uncommon for the mandibular first molar to be impacted. Treatment methods for impacted teeth include continuous examination for independent eruption, surgical exposure, subluxation after surgical exposure, orthodontic traction, and surgical repositioning. If all of these treatments fail, tooth extraction may be considered. In the first case study, an 8-year-old boy was treated with surgical exposure, after which he was fitted with an obturator. His mandibular first molar then erupted successfully. In the second case, we treated a 12 year-old boy using orthodontic traction. This study describes children with tooth eruption disorders of the mandibular first molar in mixed dentition, and reports acceptable results regarding treatment of the impacted teeth.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.1
• /
• pp.136-142
• /
• 2010

Ectopic eruption is defined as the eruption of the tooth in an abnormal position or orientation. In the molar region, ectopic eruption may cause distal root resorption and premature exfoliation of the neighbor teeth and uncontrolled space loss is followed. Prolonged partial impaction of the permanent molar may also cause undetected caries or abscess formation of the neighbor teeth. While 66% of ectopically erupting permanent molars are corrected spontaneously without treatment, the treatment is necessary for the irreversible ectopic eruption cases. The optimal treatment approach depends on a number of factors including the clinical eruption status of the molar, amount of enamel ledge and the mobility of the neighbor tooth, and the presence of pain or infection. This case report presents the results of treatment of the ectopically erupting maxillary first permanent molars and mandibular second molars using elastic separators or modified Halterman appliance with or without surgical approach.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.48 no.1
• /
• pp.115-121
• /
• 2021

Dilacerations generally involve central incisors; most often maxillary incisors rather than their mandibular counterparts. The clinical features of dilaceration include non-eruption of the responsible tooth or prolonged retention of the deciduous predecessor tooth. In Case 1, the tooth showed a dilaceration at the boundary between the crown and the root, more laterally rather than labiolingually. In Case 2, the dilacerated tooth showed a crown dilaceration with a relatively normal orientation of the dental root. In both cases, no significant space losses for eruption were observed. Moreover, it seems that unlike the maxilla with the palate, the mandibular anterior teeth are limited to show severe displacement. From these cases, it is suggested that if a mandibular permanent incisor shows a crown dilaceration or lateral dilaceration at the boundary between the crown and the root, there is a relatively high probability of spontaneous eruption of the dilacerated tooth.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.49 no.3
• /
• pp.340-347
• /
• 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.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.32 no.4
• /
• pp.693-702
• /
• 2005

Accurate timing and sequence of eruption of permanent teeth are indicies of growth and essential for pediatric dentistry and pediatric clinical orthodontics. From the children brought to the Yonsei Dental Hospital during 2001 to 2003, 654 boys and 542 girls, ranging in age from five to fourteen years, were selected and analysed. The following was concluded. 1. Eruption time of maxillary teeth is 6.81 years in boys, 6.78 years in girls for central incisor, 8.30 years in boys, 7.98 years in girls for lateral incisor, 10.28 years in boys, 10.04 years in girls for canine, 9.74 years in boys, 9.90 years in girls for first premolar, 10.87 years in boys, 10.41 years in girls for second premolar, 6.25 years in boys, 6.54 years in girls for first permanent molar, 12.21 years in boys, 12.03 years in girls for second permanent molar 2. Eruption time of mandibular teeth is 6.00 years in boys, 6.06 years in girls for central incisor, 6.99 years in boys, 6.74 years in girls for lateral incisor, 9.83 years in boys, 9.17 years in girls for canine, 9.92 years in boys, 9.75 years in girls for first premolar, 10.66 years in boys, 10.39 years in girls for second premolar, 5.99 years in boys, 5.75 years in girls for first permanent molar, 11.92 years in boys, 12.17 years in girls or second permanent molar. 3. The following eruption sequence was observed the first permanent molar erupted first, followed by the central incisor, the lateral incisor, the first premolar, the canine, the second premolar and the second permanent molar in the maxilla. The first permanent molar erupted first, followed by the central incisor, the lateral incisor, the canine, the first premolar, the second premolar and the second permanent molar in the mandible.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.33 no.2
• /
• pp.290-303
• /
• 2006

Tooth eruption is a complex and tightly regulated process that involves cells of the tooth organ and the surrounding alveolus. Osteoclast precursors must be recruited into the dental follicle prior to the onset of eruption. This function of dental follicle may be regarded as the ability of bone remodeling characterized by the interaction of osteoclasts and osteoblasts. This is because tooth eruption is a localized event in which many of the genes required for eruption are expressed in the dental follicle. RANKL is a membrane-bound protein that is a member of the TNF ligand family. which is present on bone marrow stromal cells and osteoblasts, and induces osteoclast formation and activation from precursor cell. The biologic effect of RANKL is inhibited by OPG and, in bone, the relative ratio of RANKL and OPG modulates osteoclastogenesis. To evaluate the roles of RANKL and OPG in tooth eruption and the relations with the expression pattern of Runx2, in situ hybridization was performed with mandibles of mice at postnatal stage 1, 3, 5, 7, 9 and 11. mRNA of RANKL, OPG, and Runx2 are expressed in dental follicle and surrounding tissue from P1 to 11. To determine the sites of osteoclastic activity during tooth eruption, mandibles were dissected. Peak osteoclastic activity in alveolar bone along the occlusal and basal regions was observed from P5 to 9, with osteoclasts in these regions being large and strongly TRAP-positive The specific spatio-temporal expression patterns of RANKL, OPG, and Runx2 in our study suggest that tooth eruption could be progressed through the interactions of molecular signaling among dental follicle, dental organ and alveolar bone, furthermore it means that dental follicle is quite important in tooth eruption In addition, it indicates that these genes (RANKL, OPG, and Runx2) play critical roles in tooth eruption.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.38 no.2
• /
• pp.194-201
• /
• 2011

A dentigerous cyst is the most common developmental odontogenic cyst. Patients with dentigerous cyst usually feel no pain or discomfort. If it is not treated, tooth eruption might not only be impeded, but also let the tooth translocate to the unusual area. So, early detection and appropriate treatment are important. Enucleation & marsupialization are the best options to treat a dentigerous cyst. Treatment plan depends on patient's age, health, preserve & protect of important structures, and sort of cyst. In these dentigerous cysts cases, by marsupialization and using obturator, affected tooth could be achieved spontaneous eruption into the dental arch even though they were badly dislocated.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.36 no.1
• /
• pp.84-88
• /
• 2009

Tooth impaction refers to situations where a tooth fails to erupt due to mechanical blocking and remains unerupted beyond the normal time of eruption. It is commonly found in permanent dentition, but rarely in deciduous dentition. Tooth impaction is caused by systemic or local factors, and most common etiology is odontoma. Odontoma is also commonly found in permanent dentition, and rarely in deciduous dentition. We are presenting case of 4 year and 4 month year old girl, who had impacted and disto-angulated lower left deciduous second molar due to odontoma. We removed odontoma and performed orthodontic traction of impacted lower left deciduous second molar. Then, the impacted primary molar was erupted and acceptable occlusion was obtained.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.4
• /
• pp.512-518
• /
• 2010

The impaction of the maxillary permanent incisor is a common clinical problem and is mostly found at the "labial to the alveolar process." Surgical exposure and orthodontic treatment with fixed orthodontic appliances can be considered if normal eruption of the labillay impacted tooth is not expected. Surgical exposure of the impacted tooth, that is usually under the attached gingiva or is surrounded by alveolar bone through gingivectomy and removal of alveolar bone, may give a rise to complications such as diminution in the width of the attached gingiva, inflammation of the gingiva, and the loss of marginal alveolar bone. Therefore, closed eruption technique, which includes surgical exposure and orthodontic treatment with fixed orthodontic appliances followed by repositioning of surgical flap, is preferred. However, apically repositioned flap of the impacted tooth, which is beneath the movable submucosal area or is above the alveolar crestal area, can prevent unwanted exposures and facilitate successful tooth eruption. In this report, we described esthetic results of three patients with unerupted maxillary permanent incisor who were performed with an apically positioned flap without the loss of attached gingiva.

• The korean journal of orthodontics
• /
• v.36 no.2 s.115
• /
• pp.91-102
• /
• 2006

Tooth eruption requires remodeling of surrounding tissues. This study was aimed to investigate the effect of indomethacin on the dental follicle and paradental tissues during tooth eruption by observing the distribution and expression of MMP by the immunohistochemical method. Ten mongrel dogs of ten to twelve weeks old were divided into 5 groups; four experimental groups administered indomethacin 2 mg/Kg/day and 8 mg/Kg/day orally 2 times a day for 14 days and 7 days respectively, and the control group was administered a placebo. Permanent teeth before eruption and their surrounding tissues were selected and excised. H&E staining and immunohistochemical stainings of MMP-3 and -9 were performed and examined under the light microscope. Osteoclasts, osteoblasts, periodontal ligament cells, ameloblasts and odontoblasts of the control group all expressed MMP-3 and -9. In the experimental group, osteoclasts, osteoblasts and periodontal ligament cells showed reduced expression of MMP-3 and -9. Magnitude of MMP reduction In the experimental group showed a time and dose of indomethacin administration dependent manner. These results show that indomethacin inhibited MMP-3 and -9 expression in the dental follicle and surrounding tissues and suggest that when indomethacin is administered for long periods, tooth eruption could be delayed.