• Journal of the korean academy of Pediatric Dentistry
• /
• v.36 no.4
• /
• pp.625-630
• /
• 2009

Root resorption of primary teeth usually occurs as the succeeding permanent teeth erupt, which induces differentiation of the hemopoietic cells into osteoclasts. Their root resorption pattern reflects the eruption path of the succeeding permanent teeth, and eventually the primary teeth shed as their succeeding permanent teeth erupt. Even when a permanent tooth germ is congenitally missing, root resorption of the corresponding primary tooth may still occur due to various factors, such as inflammation, traumatic occlusal force, and weakness of periodontium etc. Such congenital missing of permanent teeth is a commonly observed phenomenon in human be ing, and it often accompanies delayed retention of primary teeth. The etiologic factors for congenital missing in elude not only systemic diseases, but also local factors and human evolution process. In the radiographs of the cases in this report, the primary teeth without succeeding permanent teeth show pathologic root resorption. Root resorption progressed about 1/2~3/4 of the roots, and the surfaces of the resorption area were irregular. Considering high susceptibility of the periodontal ligament of primary teeth to root resorption, pathologic root resorption of primary teeth with delayed retention can be explained by the increased masticatory muscle force and abnormal occlusion developed during the mixed dentition. When the primary teeth without succeeding permanent teeth are lost, decision for space maintenance is required and long-term treatment plan for further prosthetic or orthodontic treatment should be establsihed.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.1
• /
• pp.91-96
• /
• 2010

Many studies have shown that there is a strong relationship between the congenitally missing primary teeth and their succedaneous permanent teeth. However, especially in case of lower anterior region, we can observe the existence of permanent teeth even though their precedent primary teeth were missed at times. The purpose of this study was to reveal the relationship between the congenitally missing primary lower anterior teeth and their succedaneous permanent teeth in Korean children. Total of 14,307 children, under 6 years of age, who attended the department of pediatric dentistry, Seoul National University Dental Hospital, Seoul, Korea from January 1st 2005 to September 5th 2008 were radiologically examined using the panoramic x-ray in order to analyze the relationship between the congenitally missing primary lower anterior teeth and their succedaneous permanent teeth. The results were as follows : 1. The prevalence of congenitally missing lower anterior teeth in primary dentition was 0.24%. The odds ratio of both the primary and permanent anterior teeth being present was 7163.5 and only the permanent anterior teeth being present was 0.79. 2. The percentage of all succedaneous permanent teeth being present was 44.12% in cases of missing lower primary anteriors. The odds ratio of at least one succedaneous permanent teeth being present in cases of bilateral primary anterior teeth missing was 1.57 times more common than in cases of unilateral primary teeth missing. 3. The odds ratio of primary missing teeth being unilateral was 2.2 times higher in females. Moreover, the odds ratio of succedaneous permanent teeth being present in cases of primary teeth missing was 2.22 times higher in males.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.32 no.2
• /
• pp.217-223
• /
• 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 the korean academy of Pediatric Dentistry
• /
• v.31 no.2
• /
• pp.136-143
• /
• 2004

The purpose of this study was to investigate the relationship between morphology and position of deciduous double teeth, and the occurrence of other dental anomalies in the same subject. Four morphological types were indentified according to Ailing's classification: type I, bifid crown-single root; type II, large crown-large root; type III, two fused crowns-single root; type IV, two fused crowns-two fused roots. Fifty-four double teeth were found in a total of 1,803 children, who had visited Wonkwang university hospital for dental treatment from January 1, 2003 to September 30, 2003. All of these children were examined clinically and intra-oral radiographs were taken. The results were as follows; 1. 49 children(2.7%) had more than one double teeth, 5 of these children had two double teeth on the bilateral side. And one child showed triple teeth which has three crowns and three roots. 2. Double teeth were predominantly situated in the anterior region, with a preference for the mandible. The ratio of cases involving central incisor and lateral incisor was higher than other cases. 3. There were 25 cases(46.2%) of missing successors among 54 cases of the double teeth. And, prevalence of the missing teeth was highest in the cases involving maxillary central incisor and lateral incisor. 4. In the case of type II(large crown-large root) had more missing successors.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.34 no.3
• /
• pp.447-453
• /
• 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
• /
• v.44 no.1
• /
• pp.11-19
• /
• 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.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.32 no.3
• /
• pp.403-408
• /
• 2005

Ankylosis is defined as a fusion of cementum or dentine with alveolar bone. Due to the loss of the periodontal ligament on the ankylotic area, the tooth is incapable of continued eruption and hence is unable to follow the normal vertical development of the neighboring teeth and alveolar process. A 6-year-old female was referred to the Dept. of Pediatric Dentistry for ankylosis of primary molars and congenital missing of permanent premolars on both jaws. She had neither specific past medical history nor trauma and infection history in oral and maxillofacial region. Radiographic finding is that the maxillary primary molars were the early onset of ankylosis and had fast root resorption rate. However the mandibular primary molars were ankylosed later and being resorbed slower than maxillary primary molars. The object of treating this case is to maintain the proper alveolar bone growth and retention of deciduous molars. The point of managing this case is as follows: Proper treatment (observation, restoration, or extraction) should be established after thorough consideration of the time of onset, the root resorption rate, progression of infraocclusion and the development of alveolar bone support. We should consider the timing of extraction of the ankylosed teeth without problem of neighbouring alveolar bone growth and tilting of adjacent teeth in the view of growth spurt. Early diagnosis is important to avoid many of the complications with infraoccluded primary molars.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.37 no.2
• /
• pp.233-239
• /
• 2010

Space loss of dental arch can appear when the proper position of teeth within the dental arch changes by a certain cause, because the balance of force makes changes about tooth position as well as alignment. The causes of space loss include proximal caries, early extraction, congenital missing of a tooth and hypodontia, etc. Among those causes of space loss, congenital missing of a tooth is more rarely observed in the primary dentition than in the permanent dentition. Congenital missing in the primary dentition is associated with that in the permanent dentition. Furthermore, it can cause space problem, such as mesial tilting or drift of adjacent teeth, space loss for permanent successors and dental arch constriction, etc. Primary lateral incisors is the most commonly involved, in the maxilla rather than in the mandible, but primary canine is rarely reported. In this patient, who visited the department of pediatric dentistry at Yonsei university dental hospital, it was observed that the maxillary right primary canine was congenitally missing and an odontoma was found insteadly. However, neither the space loss for the congenitally missing primary canine nor midline deviation is remarkable during the 2-year-10-month observation period. In addition, any clinical or radiographical symptom did not occur in spite of odontoma. Therefore, surgical enucleation of odontoma is planned according to the eruption of permanent lateral incisor or canine, unless eruption failure of permanent lateral incisor or canine nor cystic change around the odontoma is occurred. Through further evaluation, space maintainer or orthodontic treatment may be necessary.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.29 no.3
• /
• pp.407-412
• /
• 2002

The primary cause of missing teeth vary depending on the region. The loss of posterior teeth is mainly due to dental caries, whereas that of the anterior teeth occur primarily due to trauma at the age of standing and walking and secondarily from the rampant dental caries. Particularly, reduction of the arch length in the cases of premature loss of primary teeth may compromise the eruption of succedaneous permanent teeth. This may result in crowding and impaction of the permanent teeth, and asymmetry of arch, thus a careful consideration for space maintenance should be made in such cases. Space maintainer is required in the case of premature loss of primary posterior teeth, because space loss result from the approximate and centrifugal movement of the neighboring teeth. Generally, in the case of primary incisor, space loss occurs when 1) tooth contact is relevant, 2) crowding in primary dentition is present, and 3) a primary incisor is lost before the eruption of primary canine. Contrarily, in the case of primary dentition with interdental space, space loss will not be observed, mostly when a primary incisor is lost after the eruption of primary canine. Thus, using a space maintainer in cases of premature loss of primary incisor has been introduced primarily not for the purpose of space maintaining but for an aesthetic purpose, prevention of parafunctional oral habits such as tongue thrust, and of pronunciation. Additionally, few case studies have been reported of space loss in cases of premature loss of primary incisor. This study is to report cases of the space loss following the premature loss of primary incisors observed in children.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.32 no.4
• /
• pp.657-661
• /
• 2005

Various chemotherapeutic agents have been recommended for pulpotomy of primary teeth, and there are formocresol, ferric sulfate, and calcium hydroxide. Of those, formocresol has fixation effect of pulp tissue and high clinical success rate, so it is most commonly used agent. But formocresol has strong cytotoxic effects, thus many articles reported displacement and loss of permanent successor, amelogenesis imperfecta, mutation by general absorption, possibility of cancer induction. Recently, it has been reported that leakage by imperfect temporary sealing when FC-soaked cotton was inserted into the root canal caused necrosis of surrounding tissues. and that necrosis of alveolar bone related to the use of excessive formocresol. In this case, 2nd primary molar of upper left jaw was treated using formocresol in local clinic, but extracted because of lasting pain. Furthermore, symptoms didn't disappear so patient was refered to us. The patient was 8-year-old male, had foul odor from oral cavity and circular alveolar bone necrosis around the permanent successor' crown. Thus sequestrectomy was operated and observed through 19 months after operation, we found normal root development of permanent successor but no complete regeneration of alveolar bone defect and attached gingiva. Lesion of periodontal tissues by formocresol is irreversible, so we have to confirm the indication in using formocresol and pay attention to complete temporary sealing.