• Journal of the korean academy of Pediatric Dentistry
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• v.45 no.4
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• pp.484-491
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• 2018

Tooth agenesis is a common human dental anomaly and the agenesis of mandibular second premolars has been proven to be the most frequently observed. The aim of this study is to investigate tooth agenesis and delayed tooth development in patients with agenesis of mandibular second premolars. This study reviewed 9 to 15 year-old patients with agenesis of mandibular second premolars who visited the department of pediatric dentistry of Yonsei University Dental Hospital and took panoramic radiographs from January 2014 to December 2016. On panoramic radiographs, agenesis of teeth was observed and developmental delay of teeth was evaluated by the Nolla method. Among 125 patients with agenesis of mandibular second premolars, 58 patients (46.4%) showed agenesis of other teeth and 38 patients (30.4%) showed delayed tooth development. In this study, patients with agenesis of mandibular second premolars were more likely to have tooth agenesis or delayed eruption of other teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.1
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• pp.56-63
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• 2017

Delayed eruption of the first molar, without a generalized or localized cause, is usually associated with delayed development of the affected tooth. The aim of this study was to investigate the clinical features of the first permanent molar showing delayed development and eruption, and its association with developmental anomalies of other teeth. Panoramic radiographs of 40 healthy children showing delayed development and eruption of first permanent molars were analyzed. The clinical features of affected first molars and developmental anomalies of other teeth (except third molars) were evaluated. Delayed first molars were more frequent in the maxilla. The incidence of bilateral delayed development of first molars was greater than that of unilateral cases in female patients. In contrast, male patients showed unilateral delayed development of the first molar more frequently. A higher incidence of congenitally missing teeth was observed in patients with delayed first molar. In each case, delayed development or congenital absence was observed in the second molar adjacent to the delayed first molar. Overall, delayed first molar seems to be associated with congenital absence of additional teeth. Understanding the developmental mechanisms of this phenomenon requires further studies.

• Journal of the korean academy of Pediatric Dentistry
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• v.21 no.2
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• pp.555-560
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• 1994

Among the permanent teeth. the first permanent molars play the greatest role in occlusion and function. So, the congenital missing, abnormal reuption or abnormal formation of the first permanent molars in the course of arch development would inflict normal development of dental arches. Therefore, early detection of abnormal cases related to first permanent molars and understanding of current and predictable clinical problems are essential for proper occlusal guidance in children. With the aim of investigating the clinical patterns of delayed eruption of first permanent molars in children, panoramic tomograms of the childern in mixed and early permanent dentition were observed and analyzed. The results were as follows: 1. Among the delayed eruption of first permanent molars, on tooth or bilateral teeths were affected most frequently. Delayed eruption was more prevalent in maxilla than in mandible. 2. The formation of tardily erupted teeth were also delayed. 3. Delayed eruption was generally limited in first molars or molar segments. 4. Delayed eruption of first permanent molars is accompanied by abnormal position of tooth germs, for example, ectopic eruption, delayed dental age, delayed localized tooth formation and generalized congenital missing. 5. There was a tendency of delayed formation or congenital missing of second molars distal to tardily erupted 1st molars. And that was more marked in maxilla than in mandible. 6. There was reported that affected 1st molars show various size and shapes. Maxillary 1st molars showing delayed eruption showed a tendency of having 3 cusps. But, tardily erupted mandibular 1st molars showed no significant reduction in mesiodistal dimension, as reported. 7. In some cases, the delayed eruption of 1st permanent molars was associated with ectopic eruption, but their formation was not usually retarded. 8. In skeletal class III cases, there showed a tendency of mandibular 1st molars to erupt earlier than maxillary 1st molars with greater interval than in normal occlusion.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.339-344
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• 2008

When a delayed eruption of tooth is diagnosed, the causative factor should be detected before an establishment of treatment plan, if possible. Although a panoramic radiograph is enough to evaluate the position of tooth and the stage of tooth development, a 3-D Dental CT would be a powerful tool to reveal a spatial relationships between objects. The reported case showed a delayed eruption of lower left permanent canine and a mini-plate with screws adjacent to the impacted canine. Although the screws adjacent to the root of impacted tooth showed a close proximity, it was not presumed that these screws would interfere the eruption of the tooth. The impacted canine did not show any spontaneous eruption during observation. After the mini-plate and screws were removed, an orthodontic traction using elastic power chain was performed. The position of mini-plates and screws should be carefully designed to avoid damaging the tooth follicles or tooth roots in the jaw. Also the screws should be removed before an orthodontic traction to prevent damaging the root surface of impacted tooth.

• Journal of Genetic Medicine
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• v.18 no.2
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• pp.83-93
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• 2021

Charcot-Marie-Tooth disease (CMT) is the most common hereditary motor and sensory peripheral neuropathy. CMT is usually classified into two categories based on pathology: demyelinating CMT type 1 (CMT1) and axonal CMT type 2 (CMT2) neuropathy. CMT1 can be distinguished by assessing the median motor nerve conduction velocity as greater than 38 m/s. The main clinical features of axonal CMT2 neuropathy are distal muscle weakness and loss of sensory and areflexia. In addition, they showed unusual clinical features, including delayed development, hearing loss, pyramidal signs, vocal cord paralysis, optic atrophy, and abnormal pupillary reactions. Recently, customized treatments for genetic diseases have been developed, and pregnancy diagnosis can enable the birth of a normal child when the causative gene mutation is found in CMT2. Therefore, accurate diagnosis based on genotype/phenotypic correlations is becoming more important. In this review, we describe the latest findings on the phenotypic characteristics of axonal CMT2 neuropathy. We hope that this review will be useful for clinicians in regard to the diagnosis and treatment of CMT.

• Journal of the korean academy of Pediatric Dentistry
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• v.27 no.3
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• pp.383-387
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• 2000

Fusion is defined as union of two separate tooth buds at some stage in their development with confluence of dentin and characterized by separate root canal and large single crown, while gemination is defined as an attempt of the single tooth bud to incompletely divide and usually result in a single root with one root canal and two completely or incompletely separated crowns. It is sometimes difficult to decide whether an abnormally large tooth is the result of fusion of a normal and a supernumerary tooth, or of gemination; use of the term 'Double tooth' may make the clinicians avoid this difficulty(Brook & Winter). Commonly there are no symptoms, but the problems associated with these anomalies include esthetics, possible loss of arch length and delayed or ectopic eruption of the permanent teeth, caries along the line of demarcation, and periodontal disease. Commonly, it dose not need to be treated in primary dentition but in case of permanent dentition, it may be requested to be treated due to esthetics and other problems. In our case, a 8 years old girl showed a Double tooth, we attained the favorable results by performing hemisection with apexification.

• Korean Journal of Community Nutrition
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• v.24 no.2
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• pp.97-105
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• 2019

Objectives: This study examined whether the infant feeding type and duration are related to the introduction of complementary feeding, and whether the appropriate introduction of complementary feeding in infancy is related to tooth decay in toddlers. Methods: The subjects were 1,521 toddlers among 2~3 year old children in the Korea National Health and Nutrition Examination Survey from 2008 to 2015. The toddlers were divided into the appropriate group (4~6 months) and delayed group (>6 months) according to the timing of complementary feeding introduction. Results: The delayed group were 26.5% of subjects and the formula feeding period in the appropriate group and delayed group was 8.4 and 10.3 months, respectively (P=0.002). On the other hand, there was no difference in the breastfeeding period between the appropriate group and delayed group (P=0.6955). Early childhood caries was more common in the delayed group (P=0.0065). The delayed introduction of complementary feeding was associated with a risk of early childhood caries according to the logistic models (OR 1.81, 95% CI 1.27-2.57). Conclusions: The introduction of complementary feeding is associated with early childhood caries. Therefore, the importance of the proper introduction of complementary feeding in infancy should be emphasized, and public relations and education for maternal care and breastfeeding should be provided through health care institutions.

• The Journal of Advanced Prosthodontics
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• v.6 no.6
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• pp.521-527
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• 2014

This case series evaluated the clinical efficacy of autogenous tooth bone graft material (AutoBT) in alveolar ridge preservation of an extraction socket. Thirteen patients who received extraction socket graft using AutoBT followed by delayed implant placements from Nov. 2008 to Aug. 2010 were evaluated. A total of fifteen implants were placed. The primary and secondary stability of the placed implants were an average of 58 ISQ and 77.9 ISQ, respectively. The average amount of crestal bone loss around the implant was 0.05 mm during an average of 22.5 months (from 12 to 34 months) of functional loading. Newly formed tissues were evident from the 3-month specimen. Within the limitations of this case, autogenous tooth bone graft material can be a favorable bone substitute for extraction socket graft due to its good bone remodeling and osteoconductivity.

• Journal of the Korea Convergence Society
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• v.12 no.6
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• pp.39-47
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• 2021

The purpose of this study is to analyze the differences among short statured children with growth hormone deficiency, idiopathic, and normal children in order to find the effect of growth hormone deficiency on tooth developmental stage. We classified children diagnosed with short stature at the Pediatrics in Yeungnam University Hospital as subjects due to idiopathic and growth hormone deficiency. We analyzed the relationship between short stature and tooth development through the measuring of oral panorama and body index. Only the eruption of lateral incisors showed significant difference between short statured with growth hormone deficiency and idiopathic. Almost all tooth eruption was significantly delayed on short statured children with growth hormone deficiency compared to average group. In conclusion, short stature children with either growth hormone deficiency or idiopathic were affected not only in their somatic stature but also dental maturity. We look forward to this study presenting basic data for orthodontic therapy.

• Journal of the korean academy of Pediatric Dentistry
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• v.44 no.1
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• pp.11-19
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• 2017

The purpose of the study was to investigate the distribution of primary fused teeth and identify the correlation between primary fused teeth and their effect on permanent dentition. 2575 children between the age of 4 and 6 in Kyungpook National University Hospital from January 2009 to August 2015 were investigated. A total of 84 children (46 boys and 38 girls) had fused teeth. 14 of these children had two fused teeth. Prevalence of caries involvement was in 65% of maxilla and 6% of mandible. Prevalence of permanent successors missing was 86.3% in the cases involving maxillary central and lateral incisor, 70% in mandibular lateral incisor and cuspid, 11.7% in mandibular central and lateral incisor. 27 of 84 children (32.1%) had supernumerary teeth. The highest prevalence rate is seen in the cases involving maxillary central and lateral incisor. Delayed permanent tooth eruption was only observed in the maxilla because of developing supernumerary tooth. Early diagnosis of fused tooth in the primary dentition can allow the dentist to make treatment plan at the appropriate time in accordance with the tooth arrangement and tooth development.