• 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 the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.217-223
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• 2005

The term 'impaction teeth' is used to designate a tooth which remains unerupted in jaw beyond the time at which it should normally be erupted. Most cases of impacted teeth reported in the literature are permanent teeth. The impaction of primary teeth occur rarely whereas impaction of second primary molars is more numerous than all other impactions. Failure of eruption of primary teeth may cause a number of complications, such as interference with development and eruption of successive permanent teeth, malocclusion, cystic change of tooth follicle. The clinican should consider the various treatment option available (a) No treatment and observation, (b) surgical extraction (c) space regainer. Proper treatment plan should be established after thought consideration of impacted tooth and it's relation with successive permanent tooth.

• Journal of Dental Rehabilitation and Applied Science
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• v.35 no.3
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• pp.143-152
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• 2019

Purpose: The aim of this study is to investigate the characteristics of patients and teeth referred to a university dental hospital for endodontic problem. Materials and Methods: From January, 2017 to December, 2018, patients who were referred to a university dental hospital for endodontic problem were collected from clinical records. A total of 1171 patient records were analyzed. The status of the referred teeth was divided into three groups according to whether they were treated endodontically based on radiographs and clinical records at the time of referred visit. Results: 69.9% of the referred teeth were maxillary and mandibular first and second molars. The average time from referral to actual visit is 9.03 days and 65.6% of the case referred with referring letter. The most primary reasons of referral were persistent clinical symptom (pain, swelling, and sinus tract) (37.9%), diagnosis difficulty (16.7%), blockage of canal space (13.8%) and difficult tooth anatomy (11.4%). In the case of referral before endodontic treatment, the most primary reason of referral was failure to make a proper diagnosis. If the teeth were referred in the middle of endodontic treatment, the most primary reason of referral was persistent clinical symptom and blockage of canal space. In the case of referral after root canal filling, the most primary reason of referral was persistent clinical symptom. Conclusion: In the case of molars, the rate of persistent clinical symptom and blockage of canal space were the most primary reason of referral, and the rate of apical surgery and management of trauma was high in the case of anterior teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.2
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• pp.172-179
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• 2015

The developmental mechanism of root formation is a complex process. Hereditary and environmental factors may affect the morphology of the developing root. A total of 12 cases was presented with permanent first molars with abberant root morphology. Clinically, these teeth appeared as a normal crown. However, radiographically, the root was slender, twisted and characterized by irregular lengths. In addition, root trunk length was shorter and pulp chamber was obliterated. In these cases, periapical radiolucency and loss of lamina dura were often observed. In 6 cases, an abnormal root of the primary second molars were also present, as well as root malformation of permanent first molars. In 3 cases, permanent central incisors also had a dysmorphic crown. These cases almost all had medical history, such as premature birth, brain infection or congenital heart disease in infants. The present paper describes cases of permanent first molars with an abnormal root that are rarely reported in literature. This case may intensify the variation in the permanent first molar and is intended to reinforce the clinician's awareness of rare morphology of the roots.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.4
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• pp.701-704
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• 2004

In this case, we would like to discuss about the single rooted deciduous mandibular first molar. The deciduous mandibular molar of a five years old boy was shown to have a single root, bilaterally. Ordinarily, the maxilary molars have three roots and the mandibular molars have two roots. However, when the hertwig's epithelial root sheath do not invaginate properly during tooth development, root fusion can occur from the absence of root separation. Molars with fused roots not only have unfavorable crown to root ratio, but also according to many reports, have higher probability of having multiple congenitally missing teeth or dens invaginatus in the maxillary incisors, consequently requiring preventive dental treatment In addition, disorders such as ectodermal dysplasia, syndactyly, clinodactyly, bluish sclera can also be related to this condition. Root fusion is known to be of autosomal recessive inheritance. Up to date, single rooted molars have been reported several times in permanent dentitions but hardly in deciduous dentition, which is the motive for this paper.

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.1
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• pp.25-31
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• 1999

The purpose of study was to test the hypothesis that preschool children who experienced nursing caries have high dft index and caries activity in primary dentition. One thousand and seventy-five preschool children from 4 to 6 years old were examined for their caries experience and salivary invertase activity by Resazurin Disc Test. Nursing caries group was identified by the criteria of having more decayed and filled teeth among the upper incisors than among the upper molars. The prevalence of nursing caries was 15.8%. The dft index of nursing caries group was significantly higher than that of the other groups except the rampant caries group(P<0.01). The Resazurin Disc Test score of nursing caries group was significantly higher than that of the other groups(P<0.01) and there was no difference between nursing caries group and rampant caries group. Therefore, it is recommended that children who experienced nursing caries should be incorporated in the caries prevention program through the primary and mixed dentition.

• Journal of the korean academy of Pediatric Dentistry
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• v.6 no.1
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• pp.15-20
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• 1979

Sixty non-vital primary molars of forty six children who were patients at the Pedodontic Department of Seoul University Hospital, aged from 2 years 7 months to 9 years 1 month were performed for coronal pulp therapy. For the evaluation of non-vital pulp therapy, the author observed those teeth both clinically and roentgenographically. The results were as follows: 1. Coronal therapy of non-vital tooth can be accepted as one of the ordinary methods at the view of the save of tooth, time and simplicity. 2. The results were satisfactory 78.3% clinically and 68.3% roentgenographically. 3. The dissatisfactory signs were a) Clinical view There were dissatisfactory signs on 13 cases. (1) 2 teeth had fistulous opening. (2) 11 teeth reacted to purcussion and mobility. b) Roentgenographical view There were dissatisfactory signs on 19 cases. (1) 13 teeth showed roentgenolucency at bifurcation area. (2) 2 teeth showed pathological root resorption. (3) 4 teeth showed periodontal thickening.

• Journal of the korean academy of Pediatric Dentistry
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• v.50 no.1
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• pp.113-120
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• 2023

Restoring composite resins with the optimal shades for all primary teeth is a great challenge for pediatric dentists. A newly developed single-shade composite resin can exhibit a color similar to that of the surrounding tooth structure based on the structural color phenomenon. This study aims to evaluate the color adjustment potential (CAP) of a single-shade composite resin compared to conventional multi-shade composite resins in primary teeth. A single-shade composite resin and two conventional multi-shade composite resins were included in this study. Two types of specimens, a single specimen and a dual specimen, were evaluated. For single specimens, duplications of the primary second molar denture teeth were made using experimental composite resins. For dual specimens, cavities were prepared on the buccal surfaces of extracted primary second molars and restored with experimental composite resins. The L^*, a^*, and b^* values were measured using a colorimeter for the extracted teeth and specimens. The mean ΔE_ab^* values for single and dual specimens and CAP were calculated. Bonferroni post-hoc analysis was performed to confirm the statistical significance between the ΔE_ab^* and CAP values of the experimental resins. Among the single specimens, the single-shade composite resin showed significantly higher ΔE_Single compared to other composite resins (p < 0.0167). There was no significant difference between ΔE_Dual for all experimental resins. The single-shade composite resin showed highest CAP compared to other multi-shade composite resins. A single-shade composite resin exhibited the most prominent color adaptability compared to other conventional multi-shade composite resins for primary second molars. A single-shade composite resin can simplify shade matching and provide esthetic outcomes for the restoration of primary second molars.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.3
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• pp.370-377
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• 2017

Molar-incisor malformation (MIM) is a recently described dental anomaly characterized by root malformation in permanent first molars accompanied sometimes by abnormal root forms in primary second molars or enamel defects in maxillary central incisors. This report presents three cases of MIM along with a review of previous studies. Three patients exhibited abnormal root forms in the permanent first molars, with varying degrees of deformation. Two of the patients experienced medical events at birth. One of the patients was a monozygotic twin, whose twin sister exhibited normal dentition without any significant abnormalities. The present report also reviews recently reported cases of MIM in literature. In the management of MIM-associated clinical issues, consideration of microscopic features and accompanying characteristics might facilitate early diagnosis and comprehensive treatment planning.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.1
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• pp.119-125
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• 2005

In the primary dentitions, the majority of dental injuries involve the anterior teeth, especially the maxillary primary central incisors. When injuries affecting primary and permanent teeth are compared, it appears that trauma to the primary dentition is usually confined to the supporting structures, i.e. luxation and exarticulation, while the largest proportion of injuries affecting the permanent dentition is represented by crown fractures. But, cases reporting trauma affecting primary molars are unusual in the literature and several reports describe fractures of posterior teeth. The main goal of this report is to describe the repositioning treatment using removable appliances to an uncommon case of lingual displacement of primary molar that happened to a 4 year 5 month-old female child.