• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.619-624
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• 2009

Pyknodysostosis(PKND) is a rare sclerosing bone disorder that has an autosomal recessive trait, also known as Toulouse-Lautrec syndrome. Deficiency of the cathepsin enzyme K in the osteoclasts of PKND patients results in continuous endosteal bone deposits without osteoclastic resorption or remodeling. This causes a generalized increase in sclerosis and fragility of bones. Osteomyelitis in the mandible and recurrent fracture of the long bones are characteristic complicatons of PKND. The patients present typical features of PKND, such as short stature under 150 cm, open cranial suture and fontanelle, club-shaped phalanges, and underdevelopment of midface. This is a case of a 7-year-old girl with PKND, who visited our clinic with the chief complaint of anterior Open-bite and generalized crowding. The patient had been diagnosed as PKND by an orthopedist and manifested characteristic clinical and radiographic features, such as open cranial suture and fontanelle, obtuse madibular gonial angle, frontal and occipital bossing, grooved palate, club-shaped phalanges, and short stature. Orthodontic treatment was not considered because patients with PKND show abnormal bone resorption and remodeling. Instead, removal of deciduous teeth near exfoliation and TFA were performed, and periodic check-up is planned to maintain good oral hygiene.

• Journal of the korean academy of Pediatric Dentistry
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• v.36 no.4
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• pp.647-653
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• 2009

Tooth transposition is an anomaly of eruption characterized by the interchanged positions of two adjacent teeth, which is divided into complete and incomplete transposition. There are three common approaches for treating transposition: aligning the involved teeth in their transposed positions, moving them to their correct anatomic position in the arch and extracting one of the transposed teeth. Considerations in treatment plans are esthetic, function, risk of jeopardizing the roots and damaging the supporting structures, position of the root apex, developmental stages of teeth and expected compliance. The presented case reports described one maxillary canine-the first premolar transposition and two mandibular lateral incisor-canine transpositions. The former transposed teeth were arranged in their transposed position, and the latter transposed teeth were rearranged into their normal position.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.243-258
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• 2008

The purpose of this study was to investigate the relationship between the stages of calcification of various teeth and skeletal maturity stages among Korean individuals. The study subjects consisted 154 female and 179 male ranging from 7 years to 16 years of age. A total of 333 hand-wrist, cephalo-lateral and panoramic radiographs were obtained and analyzed. The tooth development of the mandibular canines, first, second premolars, and second molars were assessed according to the Dermijian's system. Skeletal maturity stages were determined from hand-wrist radiographs by using the SMI system and cephalo-lateral radiographs by using the CVMS, respectively. The results were as follows. 1. The mean ages of each stage of skeletal maturity were consistently younger in female subjects. 2. There was a high correlation between skeletal maturity of hand-wrist and cervical vertebrae in the both sexes. 3. There was a high correlation between skeletal maturity and dental calcification stage of mandibular canines, first premolar, second premolars, and second molar. 4. The mandibular second molar was tooth showing the highest correlation. 5. Percent distributions of the relationship between calcification stages of individual teeth and stages of skeletal maturity were obtained in both sexes. In summary, this suggests that tooth calcification stages from panoramic radiographs might be clinically useful as a maturity indicator of the pubertal growth period.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.305-312
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• 2008

Crown-root fractures occur throughout both crown and root, and are defined as fractures involving enamel, dentin and cementum. The fractures may be grouped according to pulpal involvement into complicated and uncomplicated one. Crown-root fractures often occur on maxillary anterior teeth and comprise 5% of injuries affecting the permanent dentition and 2% in the primary dentition. To restore crown-root fractured tooth, biologic width must be maintained. For maintaining biologic width, such methods as gingivectomy following osteoplasty or orthodontic extrusion or surgical extrusion are available. Surgical extrusion is a method that extracts the tooth and replants the fractured tooth supragingivally. It is indicated when the length of the crown fragment is less than half the length of the clinical root. In these cases, root canal treatment and crown restoration using light-cured composite resin were performed after surgical extrusion. In following periodic examinations, favorable outcome was observed.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.4
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• pp.306-313
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• 2013

Speech is complex psycho-physiological mutual process which includes many orofacial organs. Especially, teeth play an especially important role as an articulation organ in conjunction with the lips and tongue. When teeth are missing, the position of tongue and mandible is adjusted to produce correct sound. If a patient's adaptive function is inadequate for modification of malocclusion, prosthodontic and orthodontic interventions are necessary. Missing teeth of young patients should be reconstructed bacause it can cause malocclusion, decreased masticatory efficiency, articulation disorders, esthetic problem, and temporomandibular disorder. Valplast$^{(R)}$(Valplast International Corp, New York, USA) flexible denture is useful for rehabilitation due to its excellent physical properties, esthetics, and small volume. This case is regardingan intellecturally disabled patient with anarticulation disorder caused by missing lower incisors due to trauma. The patient showed improvement in articulation by using flexible partial denture. The purpose of this report is to figure out the influence of missing lower anterior teeth on articulation.

• Journal of the korean academy of Pediatric Dentistry
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• v.40 no.3
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• pp.209-215
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• 2013

Cleft lip and palate, the most common craniofacial anomalies, are severe congenital defects that have an incidence of 0.28 to 3.74 per 1000 live births. Although there has been great improvement in the field of cleft surgery, surgical approach cannot be the single solution to resolve the various problems encountered in patients with cleft lip and palate. The concept of presurgical infant orthopedics (PSIO) for gradual closure of the cleft gap and simplified surgical performance was first introduced by McNeil in 1950. Recently, there are many attempts not only to approximate the alveolar segments but also to reshape the nasal cartilage. Three infants with unilateral cleft lip and palate were referred from the department of Plastic Surgery for presurgical nasoalveolar molding (PNAM). Maxillary appliances using resin with orthodontic wire were fabricated. Then these appliance was applied until patients underwent lip surgery. In all cases, the patients could wear the appliance all day since they were able to eat even with the appliance on, This resulted in significant improvements in the nasal symmetry were found. Our appliance, namely K-NAM, extends the wearing time within the limited period and as a result it is expected to maximize the treatment effects. Used properly, this appliance would play a major role in enhancing nasal symmetry with satisfactory results.

• 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.