• Journal of the korean academy of Pediatric Dentistry
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• v.30 no.2
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• pp.210-216
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• 2003

The double teeth include gemination and fusion. The congenital missing tooth is the absence of the tooth. The purpose of this study was to investigate the prevalence of double teeth and congenital missing teeth in preschool children of Iksan city. The study population consisted of 1,031 children, 569 boys and 462 girls, aged from 17 to 84 months. The double teeth possess a variety of diagnostic and treatment problems. Gemination is the partial splitting of a single bud into two distinct entities that remain joined in a Siamese twin fashion. Fusion is the joining of two buds. Both may be normal, or one may be a supernumerary tooth. Congenital missing is the absence of one or a few teeth. Twenty three(11 boys and 12 girls) of the 1,031 children had double teeth and 17(8 boys and 9 girls) exhibited congenital missing of teeth. The prevalence of double primary teeth was 2.2%. The prevalence of congenital missing teeth was 1.6%. One subject had double teeth and congenital missing tooth at the same time. Of the 17 cases of congenital missing teeth, one girl showed it in the maxilla and aye boys and six girls had them in the unilateral side of the mandible. There were no significant differences in the prevalence of double teeth and congenital missing teeth between the boys and the girls.

• Journal of the korean academy of Pediatric Dentistry
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• v.24 no.1
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• pp.179-185
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• 1997

The prevalence of congenital teeth missing is about 2-10% of population and it is more common in permanent dentition than primary dentition. In the patients with congenital missing teeth symptoms such as conical tooth, prolonged retention of primary tooth, tooth attrition. and deficient alveolar bone growth can be accompanied. In this paper the results of clinical observation of the congenital teeth missing brothers and their familial history are presented.

• The korean journal of orthodontics
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• v.23 no.3 s.42
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• pp.319-326
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• 1993

The purpose of this study was to evaluate the frequency of congenital missing teeth and supernumerary teeth in cleft patients. The subjects were divided into bilateral cleft lip and palate(BCLP), unilateral cleft lip and palate(UCLP) and cleft palate alone(CP alone) groups. 97 cleft patients(BCLP 15, UCLP 70, CP alone 12) between 6-20 years old were evaluated. Panorama film, Orthodontic chart and initial intraoral photogram were employed for this research. The obtained results were as follows. 1. The incidence of congenital missing teeth in total cleft samples was $57.7\%$, and the incidence of supernumerary teeth was $26.8\%$. Each incidence was higher than non-cleft. 2. The incidence of congenital missing teeth was the highest in BCLP and the lowest in CP alone. 3. The number of congenital missing teeth per perso was usually one, and the frequency was higher in the maxillary lateral incisors$(67.8\%)$, and maxillary second premolar$(14.9\%)$ than other teeth. 4. Most of tooth number anomalies in cleft patients were found in maxilla, especially adjacent region to the cleft site.

• Journal of Korean Dental Science
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• v.3 no.1
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• pp.17-24
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• 2010

Objective : To investigate the prevalence of dental anomalies and to determine the associations between dental anomalies in permanent teeth Materials and methods : The samples were 1,240 patients (760 females and 480 males, mean age=15.1 years) who visited the Samsung Medical Center. Dental anomalies were diagnosed using pre-treatment dental casts, radiographs, clinical examinations, and medical/dental histories. Prevalence and association were investigated according to gender and sidedness. The Chi-square test was performed for statistical analysis. Results : The most common missing tooth was the lower lateral incisor, followed by the lower and upper second premolars. This particular dental anomaly is characteristic of the East Asian population (prevalence of congenital missing tooth=12.3%). The upper anterior area was the most frequently affected area (prevalence of supernumerary tooth was 1.5%). The presence of a supernumerary tooth was more prevalent in males than in females (p<.05, odds ratio=3.2). The most frequently affected tooth was the upper canine (prevalence of impacted tooth=4.3%). Unilateral impaction of the upper canine occurred significantly more often compared to bilateral impaction (p<.001). The prevalence of peg lateralis was 2.7%. The presence of congenital missing tooth was closely associated with peg lateralis (p<.01). If children aged 7~8 years have peg lateralis, the rest of the teeth should be checked for congenital absences. Conclusion : The early detection of dental anomalies and understanding of their associations help clinicians determine the appropriate treatment timing and methods of dealing with these anomalies.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.773-785
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• 1994

It has been generally believed that the impaction or eruption of mandibular third molars has significant correlations with the growth of the mandible, size of mandibular arch and size of teeth. The purpose of this study was to examine if there is any correlation between the status of eruption of mandibular third molars and the amount of mandibular crowding. The effect of missing of third moalrs to mandibular crowding was studied as well. 140 adult students of Yonsei University were selected and divided into three groups according to the status of mandibular third molars, Group 1) congenital missing group, Group 2) eruption group, and Group 3) impaction group. The tooth size, dimensions of the mandibular dental arch, and the amount of crowding were measured and compared. Results were as follows ; 1. There was no statistically significant difference in tooth size between the missing group and the eruption group(p<0.05). Impaction group showed larger total tooth material, inci- sal tooth material, and individual tooth size except central incisors compared to missing group (p<0.05). Impaction group showed larger total tooth material, incisal tooth material compared to eruption group as well(p<0.05). When individual tooth size was compared, impaction group had larger central incisors, canines, and second premolars than eruption group(p<0.05). 2. Missing group showed larger intermolar width than impaction group and it was stati- stically significant(p<0.05). 3. When compared the amount of total crowding, impaction group showed the largest am- ount of crowding, then eruption group, and missing group showed the least amount of crowding respectively(p<0.05). There was no statistically significant difference between missing stoup and eruption group in the amount of incisal crowding(p<0.05). Impaction group show- ed the largest amount of incisal crowding among all three groups(p<0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.3
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• pp.447-453
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• 2007

The purpose of this study was to investigate the relationship between morphology and number of deciduous teeth and the occurrence of other dental anomalies in their successors, and to evaluate the necessity of early diagnosis of dental anomalies in the primary dentition. Prevalence of double teeth and congenital missing teeth was investigated in 254(134 boys, 120 girls) panoramic radiographic films, taken by 2 to 7-year-old children in Chonnam National University Hospital from 2000 to 2005. And then it was examined that relationship of anomalies of the primary dentition and their successors. Among them 11 children(6 boys, 5 girls) had double teeth or missing teeth. And prevalence of the double teeth was 1.6% and missing teeth was 3.1%. One subject had double teeth in in the mandible and missing teeth in the maxilla. Of the 11 cases of dental anomalies in primary dentition, 7 cases had congenital missing tooth in their successors. This study suggests that the dental anomalies in the primary dentition induced high prevalence of the congenital missing of permanent successors in the permanent dentition.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.2
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• pp.245-252
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• 2009

The congenital missing of teeth is common, which takes place since the proliferation and differentiation are not allowed in that tooth bud fail to start development. The purpose of this study is to research incidence rate, number, and missing part of congenital missing teeth, and to study whether a person who has missing teeth has other abnormality of teeth or not. For this study, 1,520 subjects(aged 2.9$\sim$17) who had visited pediatric dentist department of Chonbuk national university dental hospital within 2 years were examined with an panoramic radiograph; exempting third molar missing state. The obtained results are as follows. 1. 8.88% among total subjects show missing teeth; male 9.05%, female 8.64% 2. The most frequently missing permanent teeth were the mandibular second premolars(22.3%). The most frequently missing primary teeth are mandibular lateral incisors(50%). 3. 43.3% patients have one permanent missing tooth, 34.3% have two, and 10.4% have more than six, respectively. In primary teeth, 86.7% patients have one missing tooth, and 13.3% have two missing teeth. 4. 18 patients(13.3%) have missing teeth as well as hyperdontia, while some patients have microdont, ectopic eruption, and fusion teeth.

• The korean journal of orthodontics
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• v.31 no.1 s.84
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• pp.51-61
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• 2001

Cleft lip and/or palate (CLP) is one of the most common congenital craniofacial anomalies and occurs more frequently in Asian people. Dental abnormalities in number, size, shape, and eruption of teeth are frequently associated with CLP. The purposes of this study were to investigate the effects of CLP on number, size, shape and eruption of teeth and to provide basic clinical data for diagnosis and treatment of the CLP patients. With the orthodontic and cleft charts, diagnostic models, orthopantomograms and intraoral x-ray films from 241 CLP patients who visited Dept. of Orthodontics, Seoul National University Dental Hospital, we evaluated the frequency of congenital missing teeth, supernumerary teeth, Impacted teeth, and microdontia. The results were as fellows ; 1. Frequency of congenital missing was relatively high up to $56.8\%$. Congenital missing occurred frequently in the maxillary lateral incisor and the maxillary second premolar. Among the CLP types, frequencies of congenital missing in cleft lip and Palate group and cleft lip and alveolus group were higher than those of cleft lip group and cleft palate group. And bilateral cleft showed higher frequencies than unilateral ones. 2. Supernumerary tooth was shown in $11.2\%$ of CLP patients. It occurred frequently in the area between the maxillary lateral Incisors and the maxillary canine. Among the CLP types, cleft lip group showed relatively most highest frequency. 3. Impaction was shown in $18.3\%$ of CLP patients. It occurred most frequently In the maxillary lateral incisor and the maxillary canine than other teeth. Among the CLP types, cleft lip group and cleft lip and palate group showed most highest frequencies. 4. Microdontia was shown in $15.8\%$ of CLP patients. It occurred the most frequently In the maxillary lateral incisors and maxillary canines. Among the CLP types, cleft lip and alveolus group and cleft lip and palate group showed relatively higher frequencies. There was no microdontia in cleft palate group.

• Journal of Periodontal and Implant Science
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• v.33 no.3
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• pp.383-393
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• 2003

The aim of this retrospective study was to compare the amount of marginal bone loss between upper anterior area and upper posterior area with 71 upper single-tooth restorations on 2 stage machined $Br{{\aa}}nemark$ implants since Jan 1995. The second aim was to compare the bone defect group which had dehiscence and fenetration and the others in the upper anterior region. The results were as follows. 1. The most frequent reason of missing tooth in the upper anterior region was trauma by 61%. While upper posterior region showed various reasons such as congenital missing, advanced periodontitis, trauma. 2. Peri-implantitis with fistula occurred 1 of 41 implants in the upper anterior group in 1 year after loading and 2 of 32 implants in the upper posterior group failed before loading. The 1 year success rate of upper anterior group was 97.56 %, and 93.75 % for upper posterior group. 3. The mean marginal bone loss in the upper anterior group was 0.44${\pm}$0.25 mm, while 0.57${\pm}$0.32 mm in the upper posterior group. There was statistically significant difference in the amount of mean marginal bone loss (P${\pm}$0.10 mm at one year, and 0.48${\pm}$0.26 mm for the control group. No statistically significant difference of mean marginal bone loss was showen between bone defect group and the others at implantation. According to the results, the upper anterior region showed less marginal bone loss than the upper posterior region. In case of missing single upper tooth, careful consideration on recipient residual ridge to determine proper implant diameter and length, sufficient healing time, proper loading would lead to implant success. Single tooth implants in the maxilla seemed to be an alternative to fixed partial dentures without damage to adjacent teeth.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.4
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• pp.679-684
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• 2007

Odontoma is the most common benign odontogenic tumors, and have been defined as mixed odontogenic tumor composed of epithelial and mesenchymal cells. Odontoma is believed to be hamartomatous rather than neoplastic in nature. The classification by WHO divides odontoma into 2 groups such as complex odontoma and compound odontoma. Compound odontoma comprises dental tissues, resembling the morphology of a tooth and has predilection for the anterior maxilla. In contrast, complex odontoma has unorganized mass, not resembling the normal tooth and has predilection for the posterior mandible. Odontoma is almost asymptomatic, so it is usually found on routine radiographic examination. Common presenting symptom is impacted or unerupted permanent teeth and retained primary teeth, but coexistent odontoma and congenital missing of permanent teeth is a very rare condition. The recommended treatment for an odontoma is conservative surgical excision, with care taken to remove the surrounding soft tissue. This report presents 2 patients with compound odontoma of the mandible who have congenital missing of the permanent teeth.