1.Comparison of Partial Pulpotomy in Permanent Molars Using Different Pulp Capping Agents and Restoration Materials
Jimi LEE ; Nanyoung LEE ; Sangho LEE ; Myeongkwan JIH
Journal of Korean Academy of Pediatric Dentistry 2020;47(2):148-156
The purpose of this study was to compare the success rates of two pulp capping materials, BiodentineTM and RetroMTA®, used for partial pulpotomy in permanent molars after carious exposures and to compare the final restorative outcome of using composite resin to that of using a stainless steel crown. We studied children who were diagnosed with dental caries of permanent molars and underwent partial pulpotomy. The patients were followed up for more than 1 year. Clinical and radiographic evaluation were used to evaluate the success of each treatment. Fisher's exact test was used to compare the outcomes of two groups. For pulp capping agents, the success rate of using RetroMTA® was lower than that of using BiodentineTM(p < 0.05). Final restoration with composite resin was less successful than restoration with an stainless steel crown(p < 0.05). In combination of pulp capping agents and final restoration material, RetroMTA®- composite resin shows the lowest success rate(p < 0.05).
2.Eruption Guidance of Horizontally Impacted Permanent First Molar with Primary Retention of Primary Second Molars: Case Reports
Garam YOON ; Nanyoung LEE ; Sangho LEE ; Myeongkwan JIH
Journal of Korean Academy of Pediatric Dentistry 2020;47(2):219-227
Tooth eruption involves a complex developmental process of tooth migration from the dental follicular origin to the final occlusion position in the oral cavity via the alveolar process. Disturbance of tooth eruption can occur at any point in a series of eruption stages; however, horizontal impaction of the mandibular first molar and primary retention of the primary mandibular second molar are rarely observed simultaneously. This study describes the treatment for two cases of horizontally impacted first molar with primary retention of primary molar. The primary retention of the primary mandibular second molar was extracted, and orthodontic traction was applied to the horizontally impacted primary mandibular first molar. Subsequently, displacement of the premolar tooth bud was improved and space regaining for eruption was achieved, guiding to normal eruption of the first molar.
3.2-Step Needle Insertion Technique to Reduce Pain in Children during Local Anesthesia
Suyoung PARK ; Sangho LEE ; Nanyoung LEE ; Myeongkwan JIH
Journal of Korean Academy of Pediatric Dentistry 2020;47(2):99-108
This study was performed to evaluate the effectiveness of the 2-step needle insertion technique to reduce pain during local anesthesia in children. Local anesthesia was performed bilaterally using conventional technique and a 2-step technique, and to compare the degree of pain using the 2-step with that using the conventional technique during local anesthesia using a pain scale.
The pain scores were significantly different between the conventional technique and the 2-step insertion technique at 5.82 ± 2.14 and 2.57 ± 2.09, respectively (p < 0.001). The subjective degree of pain based on gender, age, and Frankl’s behavior rating scale was significantly lower in the 2-step insertion technique (p < 0.001). Subjective pain levels in the area of maxilla and mandible, anterior and posterior parts were lower in the group treated using the 2-step insertion technique (p < 0.001).
The 2-step insertion technique is a simple and effective way to reduce pain during local anesthesia not only in children with a positive attitude to dental treatment, but also in children with negative attitudes, and is thought to be more effective if combined with application of topical anesthesia or distraction.
4.Traumatic Bone Cyst in the Mandibular Symphysis : Case Reports
Minah SUNG ; Nanyoung LEE ; Sangho LEE ; Myeongkwan JIH
Journal of Korean Academy of Pediatric Dentistry 2021;48(4):476-483
Traumatic bone cyst (TBC) is an asymptomatic lesion seen most in adolescents. TBC is found incidentally on routine panoramic examinations and appears as a relatively well-demarcated unilocular radiolucency with scalloped margins. Histological examination reveals a vacant cavity of cancellous bone usually unlined or very occasionally lined with a thin connective tissue layer. The lack of lining epithelial membrane is common histological feature. The most affected site is between the mandibular canine and third molar. The involvement of the mandibular symphysis is rare. The etiopathogenesis of the TBC is unclear. TBC is treated with surgical exploration and curettage; new bone is formed in place of the lesion within 6 - 12 months of surgery. Diagnosis of TBC prior to surgical intervention has limitations in most of the cases. Both of our patients were diagnosed through radiological examination and biopsy. Neither patient had a history of trauma. After surgery, the panoramic radiograph and CBCT were used to confirm bone healing.
5.Changes of Occlusion following the Placement of Preformed Metal Crown to the Permanent First Molar in Children and Adolescents
Jiwoong KIM ; Nanyoung LEE ; Myeongkwan JIH ; Sangho LEE
Journal of Korean Academy of Pediatric Dentistry 2022;49(1):45-56
The purpose of this study is to evaluate changes of occlusion following the placement of preformed metal crown in the permanent first molar affected by severe caries or hypomineralization.The study was conducted on 24 patients who met the criteria among the patients with occlusion in the permanent first molar reaching the occlusal plane. Restorative treatment was performed on one first molar using preformed metal crown. Before treatment, immediately after treatment, after 4 weeks, and after 8 weeks, the T-scan Ⅲ was used for measuring distribution of bite force at the maximum intercuspal position, and overbite was measured with digital vernier calipers and change of dental midline was surveyed. After 8 weeks, questionnaires survey was conducted.In most cases, immediately after treatment, the distribution of bite force between the restored side and non-restored side of arch was reversed compared to before treatment, and the overbite was decreased. However, after 4 weeks, bite force of the left and right side was balanced and the distribution of bite force on the restored and non-restored permanent first molars had similar values. Also, the changed overbite and midline were returned to pre-treatment status and there was no significant temporomandibular joint and masticatory discomfort after treatment.In this study, it was confirmed that spontaneous occlusal equilibrium was achieved one month after the placement of preformed metal crown.
6.Evaluation of the Pressure of the Tongue, Lips, and Cheeks in Patients with Myofunctional Therapy and Appliance
Minah SUNG ; Myeongkwan JIH ; Nanyoung LEE
Journal of Korean Academy of Pediatric Dentistry 2023;50(1):13-23
The purpose of this study was to compare the values of tongue pressure (TP), lip closing pressure (LCP), right buccal pressure (RBP), and left buccal pressure (LBP) and check the intraoral muscle imbalance and observe the changed values according to the myofunctional therapy (MFT) period. The MFT with a prefabricated appliance was performed on patients with certain muscular dysfunctions due to oral habits. And the improvement of perioral muscles was evaluated using a balloon-based pressure measurement. The group consisted of 21 patients with oral habits such as chronic mouth breathing, finger sucking, lip sucking, tongue thrusting, and atypical swallowing habits. When comparing the two groups before treatment, there was a significant difference in TP and LCP values. The TP increased the most in the first month since the start of myofunctional therapy, and the LCP increased the most between 3 and 6 months after treatment began. The values of TP, LCP, RBP, and LBP in the control group measured before treatment were very similar to the results of the experimental group 6 months after the myofunctional therapy. When the MFT was steadily performed, it was possible to observe a noticeable increase in the tongue and lip closing pressure. At least 6 months of myofunctional therapy is recommended for patients with intraoral muscle imbalance due to oral habits.
7.Management of Transposed Maxillary Canines and Peg-shaped Lateral Incisors: Case Reports
Sooin JUNG ; Myeongkwan JIH ; Nanyoung LEE
Journal of Korean Academy of Pediatric Dentistry 2025;52(1):117-128
Tooth transposition is a rare dental anomaly in which two adjacent teeth develop and erupt in altered positions. It is often associated with other dental abnormalities, such as congenitally missing or peg-shaped lateral incisors. This case report presents 3 pediatric patients diagnosed with complete unilateral transposition of the maxillary canines and peg-shaped lateral incisors. In all cases, the transposed teeth were aligned in altered positions to minimize potential complications, such as root resorption. Orthodontic traction and alignment were performed, resulting in satisfactory tooth alignment without significant complications.
8.Evaluation of Tooth Reduction for Prefabricated Zirconia Crowns in Primary First Molars Using 3D Scanner
Dabin KIM ; Myeongkwan JIH ; Nanyoung LEE
Journal of Korean Academy of Pediatric Dentistry 2025;52(1):76-88
The aim of this study was to quantitatively evaluate the amount of tooth reduction required for prefabricated zirconia crowns (PZCs) of maxillary and mandibular primary first molars by evaluating different areas of the tooth. A total of 271 intact primary first molars were scanned using a 3D scanner, and PZCs were virtually superimposed to analyze the amount of tooth reduction. The results indicated that in the maxillary primary first molars, more reduction was required on the buccal occlusal surface compared to the lingual occlusal surface, whereas in the mandibular primary first molars, a similar amount of reduction was required on both buccal and lingual occlusal surfaces. For the axial surfaces, the maxillary primary first molars required the most reduction on the lingual surface than buccal and proximal surfaces, whereas the mandibular primary molars required significantly less reduction on the lingual surface. Additionally, a trend was observed where larger crowns required less reduction on the buccal and lingual surfaces. This study provides detailed guidelines on the required amount of reduction for PZC restorations, contributing to more efficient preparation in clinical practice.
9.Survival Rate of Second Primary Molars after Treatment with the Halterman Appliance: A Retrospective Study
Sooin JUNG ; Myeongkwan JIH ; Nanyoung LEE
Journal of Korean Academy of Pediatric Dentistry 2025;52(2):142-151
This retrospective study evaluated the 24-month survival rates of second primary molars after treatment of ectopic eruption of the maxillary permanent first molar with the Halterman appliance. Patients diagnosed with ectopic eruption at the Department of Pediatric Dentistry at Chosun University Dental Hospital and three private pediatric dental clinics between January 2017 and December 2021 were included. This study involved 113 children (66 boys and 47 girls) aged 5 to 9 years, utilizing electronic medical records and panoramic radiographs for evaluation. Survival analysis of second primary molars was conducted using the Kaplan-Meier method and Cox proportional hazards regression models. The findings indicated that the degree of root resorption significantly influenced survival rates, with 24-month cumulative survival rates of 90.9% for grade 1, 88.6% for grade 2, 68.9% for grade 3, and 33.3% for grade 4. The risk of premature loss was approximately 8.7 times higher in grade 4 compared to grade 1. No significant correlation was found between the survival rates and factors such as patient age, mesial angulation of the permanent first molar, or gingival emergence status of the permanent first molar. This study emphasizes the critical need to evaluate root resorption in second primary molars and to carefully consider anchorage design in the treatment of ectopically erupted permanent first molars, highlighting directions for further research.
10.Management of Transposed Maxillary Canines and Peg-shaped Lateral Incisors: Case Reports
Sooin JUNG ; Myeongkwan JIH ; Nanyoung LEE
Journal of Korean Academy of Pediatric Dentistry 2025;52(1):117-128
Tooth transposition is a rare dental anomaly in which two adjacent teeth develop and erupt in altered positions. It is often associated with other dental abnormalities, such as congenitally missing or peg-shaped lateral incisors. This case report presents 3 pediatric patients diagnosed with complete unilateral transposition of the maxillary canines and peg-shaped lateral incisors. In all cases, the transposed teeth were aligned in altered positions to minimize potential complications, such as root resorption. Orthodontic traction and alignment were performed, resulting in satisfactory tooth alignment without significant complications.