• Journal of the korean academy of Pediatric Dentistry
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• v.26 no.2
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• pp.275-283
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• 1999

Authors evaluated 152 patients at the department of Pediatric Dentistry in Seoul National University Hospital through clinical records and radiographs. And the following features were studied ; age, sex distribution, number of mesiodens per patients, location, status of eruption, shape and orientation of crown, and complication. From the above results, the relationship between features of mesiodens and complications were evaluated using chi-square analysis. 1. Complications due to the presence of mesiodens did not occur in 31.6%, delayed eruption of adjacent teeth was observed in 33.6%, midline diastema in 22.4%, rotation in 8.6%, displacement in 3.3%, and crowding in 0.7% of all evaluated patients. 2. As compared with the above 8.5 year group, in the under 8.5 year group, the frequency of complications was significantly higher(P<0.05). As compared with those positioned lingually, in mesiodens labially or within the arch the frequency of complications was significantly higher(P<0.01). Also, the frequency of complications was significantly higher when the mesiodens was tuberculate in form(P<0.05). 3. Of the 104 patients with complications, the frequency of delayed eruption was significant higher in the under 8.5 year group, and in above 8.5 year group, the frequency of malocclusion was significantly higher(P<0.05). When mesiodens were located in the midline region, the frequency of malocclusion was significant higher, while in case with laterally positioned mesiodens the frequency of delayed eruption was significantly higher(P<0.01).

• Maxillofacial Plastic and Reconstructive Surgery
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• v.23 no.3
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• pp.263-269
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• 2001

Median cleft of the lower lip and/or mandible is a rare congenital anomaly, first mentioned by Couronne in 1819. Monroe(1966), Fujino(1970), Ranta(1984) and Oostrom(1996) conducted comprehensive reviews and list cases in literature. Median cleft varies greatly, from a simple vermilion notch to a complete cleft of the lip involving the tongue, the chin, the mandible, the supporting structures of the median of the neck, and the manubrium sterni. The associated anomalies include ankyloglossia, cleft tongue, neck contraction, heart lesion, absence of hyoid bone, and so on. The etiology of median cleft is unknown. Various possibilities, such as failure of mesodermal penetration into the midline, failure of fusion of mandibular processes, external factors apart from the embryogenic pattern such as pressure, position in utero, circulatory failure caused placental adhesion, diseases in pregnancy, and so on, have been discussed. A 8-year-old girl was referred to the Dept. of Oral & Maxillofacial Surgery, Kyungpook National University Hospital and had been aware of the fact that at birth "she had something wrong with her mouth." Shortly after birth she had been examined by a plastic surgeon and at that time surgical procedure had been performed to release the tongue from the lower jaw and lip at local hospital. On admission, she had a slight notching of lower lip and two fibrous frenum ran from the lip along the ventral surface of the tongue, diastema between her mandibular central incisors, and slightly constricted bifid mandible associated independent movement of the two halves of mandible. The patient had autogenous iliac bone graft to reconstruct the mandibular midline defect. The postoperative result was uneventful. In future, the correction of the soft tissue deformities such as notching of the lower lip and partial ankyloglossia will be required for the esthetic and functional improvement.

• Journal of the korean academy of Pediatric Dentistry
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• v.35 no.2
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• pp.367-375
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• 2008

Anchorage plays an important role in orthodontic treatment. Skeletal anchorage like the miniscrew is considered a more effective method in anchorage control than conventional anchorage which needs much patient's cooperation. The miniscrew offers many advantages. 1) It is easy to insert and to remove. 2) It can endure the force needed for moving teeth. 3) It can be immediately loaded and 4) Patient cooperation is not needed. 5) It is economic compared to other skeletal anchorage systems. In comparison to adult's bones, children's bones have comparatively poor bone quality and quantity. Therefore, it is hard to obtain primary stability in younger patients. However, if the miniscrew can be retained successfully, it will be effective in many orthodontic treatments. In these cases, we used the miniscrew in correcting of diastema, in aligning dental midline, and in rendering a forced eruption of impacted tooth in mixed dentition patient. We obtained satisfactory results.

• The Journal of Korean Academy of Prosthodontics
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• v.36 no.2
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• pp.245-257
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• 1998

This study was performed to measure the changes of the mandibular movement and the masticatory muscular activities - anterior temporal and masseter muscle of both side - reflected by intentional increase of anterior guidance angie. For this study, 5 volunteers (3 males and 2 females with average age of 24.0) were selected. Each volunteer had Angle's classification I and did not have any missing tooth except third molar and any extensive restorations. Metallic guide plate was made at volunteer's working model fabricated by improved dental stone and cemented to the palatal surface of maxillary central incisor using resin cement(Panavia $21^{(R)}$) and then adjusted not to give any occlusal interferences at intercuspal position. The activity of masticatory muscles and the changes of mandibular movement were recorded by EMG and Sirognathograph in Biopak analysing system(Bioresearch Inc., Milwaukee, Wisconsin, USA). Measurement was done at before experiment, immediatley after placement, 1 week after placement, immediately after removal, and 1 week after removal. The results were as follows: 1. Moderate phonetic disturbance and mild headache were occured to 3 volunteers for 2 days after setting and 1 volunteer had positive reaction to percussion and slight midline diastema. But all of these clinical signs were diappeared 1 week after removal and the other volunteer did not have any special clinical sign. 2. In the EMG of the mandibular rest position, the mean value of anterior tempotal muscle was increased immediately after placement(p<0.01) and then decreased 1 week after placement(p<0.05) and increased 1 week after removal(p<0.05) but not recovered as before experiment. The mean value of masseter muscle was decreased during the experiment period. 3. In the EMG during mandibular protrusive movement, all muscular activity was decreased during the experiment period. Reduced activity was not recovered 1 week after removal(p<0.03). 4. During the habitual opening, anteroposterior movement of mandible was decreased immediately after placement(p<0.05) and then increased 1 week after placement but not statistically significant(p>0.1). Vertical movement was not shown significant difference during the experiment period(p>0.1). Lateral movement was decreased immediately after placement(p<0.05) and then increased 1 week after placement but not recovered as before experiment. The opening and closing velocity of mandible was shown minor changes but not statistically significant. 5. During the habitual opening, anteroposterior movement of mandible was decreased 1 week after placement(p<0.05) and then increased immediately after removal and recovered 1 week after removal as before experiment. Vertical movement was not shown significant changes. Lateral displacement of mandible was increased continuously and recovered 1 week after removal. Opening velocity was temporarily increased immediately after removal but recovered and closing velocity was not shown significant changes. 6. During the right side chewing, anteroposterior movement of mandible was increased immediately after removal but recovered and vertical movement was not shown statistically significant results. Lateral displacement and velocity of mandible were not shown significant results. 7. During the left side chewing, the changes of mandibular movement pattern were not shown statistically significant results.

• Journal of the korean academy of Pediatric Dentistry
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• v.41 no.3
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• pp.207-217
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• 2014

The purpose of the present study was to evaluate the relationship between the malocclusion and dental caries in adolescents with permanent dentition. The subjects of the study were 385 adolescents aged 12 to 15 years. Dental Aesthetic Index (DAI) and DMFT index were recorded as clinical indicators of malocclusion and dental caries. The mean Dental Aesthetic Index (DAI) score of the subjects was 12.42 and the mean DMFT index of the subjects was 2.89. Four students (1.04%) were included in the group of orthodontic treatment mandatory, which signifies the handicapping malocclusion. Moreover, the result of gender-specific analysis of the DAI components observed that the prevalence of midline diastema and mandibular overjet were significantly higher among boys (p < 0.05). In 7 components (missing teeth, incisal segment crowding, maxillary anterior irregularity, mandibular anterior irregularity, mandibular overjet, anterior openbite, antero-posterior molar relationship) among the 10 DAI components, abnormal groups showed significantly higher DMFT index than normal groups (p < 0.05). The subjects in the group of definite to handicapping malocclusion (DAI ${\geq}$ 26) showed significantly higher DMFT index than the subjects in the group of minor or no malocclusion (p < 0.01). In addition, the DAI score had significant positive linear correlation with the DMFT index (r = 0.584, p < 0.01). Consequently, the current findings suggested a positive relationship between the malocclusion and caries prevalence. And several specific types of malocclusion were supposed to be significantly correlated with dental caries.