• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.3
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• pp.177-184
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• 2013

Calcium hydroxide mixture medicaments can nearly be considered to be the ideal primary tooth filling material. However, long-term application of calcium hydroxide combinations as an intra canal medicament softens dentin. The aim of this study was to evaluate the effect of calcium hydroxide on the microhardness of root dentin of primary tooth. For the study, 60 extractedprimary incisors were divided into 3 groups (no medicament, calcium hydroxide/iodorform mixture, and calcium hydroxide/distilled water mixture). After the cleansing and shaping of canals, calcium hydroxide medicaments were applied and stored for different periods of time (1, 7, 30, 90 days). The root was horizontally sectioned into 2 mm thick specimens and the microhardness was measured using Vickers microhardness tester. The results were as follows : Root dentin microhardness of primary teeth decreased with long term exposure to calcium hydroxide medicaments according to the experimental period and showed statistically significance (p < 0.05). Root dentin microhardness of primary tooth filled with calcium hydroxide mixed with distilled water showed more decrease than filled with Vitapex and showed statistically significance (p < 0.05). Root dentin microhardness of a control group without exposure to calcium hydroxide decreased according to the experimental period and showed statistically significance (p < 0.05).

• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.4
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• pp.669-676
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• 1999

The dentigerous cysts originate through alteration of the reduced enamel epithelium after amelogenesis is completed, with accumulation of fluid between the layers of the enamel epithelium, or between this epithelium and the tooth crown. Next to the radicular cyst, they are the second most common type of odontogenic cyst. They occur over a wide age range with a peak frequency in the 2nd to 3rd decade. A substantial majority involve the mandibular third molars, followed in order of frequency by the maxillary permanent canines, mandibular second premolars, and maxillary third molars. With regard to the treatment of these cysts, the marsupialization procedure with obturator is recommended during the age when the eruptive force of the teeth is still strong. It can be effective when preservation of the displaced teeth is desirable. We treated the dentigerous cyst by marsupialization with obturator and guided the eruption of involved teeth to normal position. And we got the results as follows : 1. Severely dislocated teeth associated with dentigerous cyst erupted into proper position. 2. The enamel hypoplasia and the root deformity were observed some cases. 3. The bone expansion and defect were healed without infection and recurrence.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.644-648
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• 2005

Supernumerary tooth was resulted from excessive proliferation of dental lamina and associated with familial tendency and a congenital syndrome such as Cleidocranial dysostosis or Gardner's syndrome. Incidence reports identify a range of $0.3{\sim}0.8%$ in primary dentition, $1.0{\sim}3.5%$ in permanent dentition with males being affected twice as frequently as females, maxilla nine times as frequently as mandible. The most common supernumerary tooth is the mesiodens, which located between the maxillary central incisors, and the next common site is the fourth molar and lateral incisors. Supernumerary teeth are uncommon in the mandible, but premolars are the most common supernumerary teeth and occurrence is very rare in the incisor region of the mandible and the incidence is 2%. We need a early diagnosis and appropriate treatment plan because of possiblilty of diastema and eruption failure displacement, rotation of the associated permanent teeth, root resorption and dentigerous cyst with presence of the supernumerary teeth. In this two case, one supernumerary tooth located in the mandibular incisor region, the other supernumerary tooth located in premolar region. We could get normal alignment of mandibular dentition by extraction and orthodontic treatment.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.2
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• pp.229-235
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• 2005

A problem that affects children's dentitions is the harmful habit which is difficult to treat. Harmful habits for children are such as abnormal swallowing patterns, low/forward tongue rest posture problem, habitual open-lips resting posture, habitual mouth-breathing, excessive digital sucking habit and tongue thrusting. Tongue thrusting habits cause a bit of cranio-facial skeletal changes and a great deal of dental malocclusion such as anterior open bite. Anterior open bite causes masticatory, speech, and esthetic problems in the growing children and difficulties in diagnosis, treatment, and the prediction of its prognosis. The treatments of such abnormal behaviors involve orofacial myofunctional therapy and using of habit breaking appliance. The prognosis is not determined by the presence of severity of oral habit but the skeletal tendency of the patient. Usage of tongue crib resulted in not only the discontinuance of the habit but also improvement in overbite and overbite. This study showed that relatively successful results could be generated by using removable tongue crib and myofunctional therapy in the case of openbite related to tongue thrusting habit.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.2
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• pp.267-272
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• 2004

This case report describes an uncommon treatment method for crown-root fractured incisor with immature root. A 7-year-old girl was referred for treatment of crown-root fractured maxillary central incisor. The fracture line extended to 1/2 of the total tooth length with incomplete root formation. The prognosis of crown-root fracture is usually poor and extraction is usually undertaken. But, in the mixed dentition, extraction of maxillary permanent incisor results in many complications, such as resorption of alveolar bone, poor esthetics, pronunciation and mastication. Conservative therapy in the permanent dentition comprises of few treatment modalities; supragingival restoration, gingivectomy, orthodontic extraction of apical fragment, surgical extrusion of apical fragment with or without rotational replantation. However, in this case, these indications are not applicable, so intentional replantation with adhesive resin system is the treatment of choice. The tooth was followed-up for 12 months. Currently, there are no symptoms. Since this modality adopts the respective advantages of both intentional replantation and adhesive treatment, it might be the treatment of choice in cases of vertical crown-root fracture.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.1
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• pp.81-90
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• 2007

The purpose of this study was to assess the effect of light-tip distance on the shear bond strength of a visible light-cured glass ionomer cement(Fuji Ortho LC ; GC, Japan) cured with three different light curing units : a halogen light(Elipar Trilight ; 3M ESPE, Seefeld, Germany), a Light Emitting Diode (LED, Elipar Freelight2 ; 3M ESPE, Seefeld, Germany) and a plasma arc light (Flipo ; LOKKI, France). 1. When used at a distance of 0mm from the bracket, the three light curing units showed no statistically different shear bond strengths. At distance of 3 and 6mm, no significant differences were found between the halogen and plasma arc lights, but both had significantly higher shear bond strengths than the LED light. 2. The halogen light and plasma arc light showed that no significant differences in bond strength were found among the three distances. Using the LED light, a greater light-tip distance produced significantly lower shear bond strengths.

• Journal of the korean academy of Pediatric Dentistry
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• v.34 no.1
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• pp.162-168
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• 2007

Impaction of the maxillary central incisor may cause social, esthetic, and functional problems in children. There are various means of treatment for the inverted maxillary central incisor, such as extraction, surgical opening followed by orthodontic traction surgical repositioning or intra-alveolar autotransplantation prior to extraction. In this case, we surgically repositioned the inverted maxillary central incisor to normal semi-erupted position in a 5-year-old boy The developmental stage of the inverted tooth was Nolla's 6.5, which indicates formation of less than one third of the root. After surgical reposition, we did follow-up for 21 months, expecting spontaneous growth Unfortunately, poor prognosis was noted further root was not observed. Such failure seems to originate from possible injury on Hertwig's epithelial root sheath by surgical trauma. We performed surgical repositioning to retain the tooth instead of extraction. However, arrest of root development occurred which is one of the critical complications. In order to increase the success rate of the surgical reposition procedure, minimal surgical trauma is required as well as selection of adequate indication and decision of proper time of treatment considering the stage of root development.

• Journal of the korean academy of Pediatric Dentistry
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• v.39 no.1
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• pp.58-65
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• 2012

The crown-root fracture is defined as a fracture of tooth that contains enamel, dentin and cementum with or without pulp exposure. Generally the fracture lines place obliquely from labial surface, between incisal edge of the crown and marginal gingiva, to palatal surface subgingivally. If the fracture line is located supragingivally, the removal of tooth fragment and supragingival restoration can be performed. In subgingival fracture line, the surgical exposure, orthodontic eruption or surgical eruption can be considered. If the fracture line is too deep to restorate, extraction or decoronation can be selected. In children and adolescents, the extraction should be the last option. Another option to select before extraction is the restoration using fiber-reinforced post and the reattachment of tooth fragment. The fiber-rainforced post enhances the retention and the durability of tooth fragment. The reattachment of crown fragment using resin adhesive system is considered minimal invasive treatment biologically. This case reports the treatment of crown-root fracture using the reattachment of crown fragment and the insertion of fiber-reinforced post.

• Journal of the korean academy of Pediatric Dentistry
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• v.38 no.1
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• pp.75-81
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• 2011

Supernumerary teeth are in excess of the normal number of teeth in either the primary or permanent dentitions. They are classified into supplemental teeth resembling those of the normal series and rudimentary teeth with abnormal shapes, according to their form. Most of the supernumerary teeth are rudimentary form, and supplemental teeth are much less common. Sulppemental teeth are most common in the permanent maxillary lateral incisor area and clinicians should be careful with differential diagnosis from normal teeth. Unerupted supernumerary teeth may produce several complications such as delayed eruption, displacement of permanent teeth, diastema, root resorption and cyst formation. Early detection and proper treatment plan according to the tooth alignment and root formation stage are important. Here we report 3 cases of unilateral or bilateral normal incisor shaped supernumerary lateral incisors treated by eruption observation, surgical extraction and orthodontic treatment with resin build-up.

• Journal of the korean academy of Pediatric Dentistry
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• v.37 no.3
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• pp.381-386
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• 2010

As the vertical fracture occurs at the various locations following the long axis of a root, treatment method of crown-root fractured anterior teeth is decided according to the depth. If the fracture line is close to the crown, gingivectomy, orthodontic - forced eruption or surgical extrusion of apical fragment could be done. If the line is over 1/3 length of the root, the prognosis is poor and extraction is usually undertaken. However, extraction of maxillary incisor at growing children causes many complications such as esthetic, phonetic problem and alveolar bone resorption. Therefore, preservation of tooth is the highest priority. Recently, intentional replantation with composite resin could be considered as alternative treatment of crown-root fractured anterior tooth. This report presents a patient in mixed dentition with deep vertical crown-root fracture of the maxillary permanent central incisors by trauma. Intentional replantation of the fractured teeth was performed using composite resin. After 2 years, specific clinical symptom has not been found and the patient was satisfied of esthetic result. This method suggests the new technique to preserve a tooth as an alternative to extraction, although it is technically sensitive and the reports of long-term prognosis is insufficient.