• Journal of the korean academy of Pediatric Dentistry
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• v.8 no.1
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• pp.21-24
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• 1981

The author observed a case of ectopic erupted maxillary second premolars and impacted mandibular second premolars due to premature loss of the primary second molars. The treatments were done as follows: 1. In the maxilla, the teeth arrangement problem was corrected with removal of the ectopic erupted second premolars. 2. In the mandible, normal dentition was established with surgical removal of the left second premolar and removal of the permanent first molar in right side combined by orthodontic therapy.

• Journal of Oral Medicine and Pain
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• v.7 no.1
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• pp.41-46
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• 1982

The patient, 11 yeats old male was examined for routine oral health care. He had been hospitalized for treatment of nephritis. Hos physical condition os mental retarded & undergrowth state. In oral examination, notch on cutting edge and screw-driver shaped crown of maxillary central incisors, narrow crown and dwarfed & pinched occlusal surface of lower first molars and scars(rhagades) on the angle of the lip were shown. We diagnosed the above symptoms as dental defects of congenital syphilis; Huchinson's inscisors and mulberry molar.

• The korean journal of orthodontics
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• v.30 no.6 s.83
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• pp.687-698
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• 2000

The purpose of this study was to evaluate the changes of skeletodental patterns during Class II treatment and its retention period. Forty two patients of Class II malocclusion, which was treated with nonextraction or first premolar-extraction were selected and their lateral cephalograms were examined in this study. Various skeletodental changes in lateral cephalograms of pre-treatment, post-treatment and retention were measured by superimposition in reference to the cranial base for jaws, the palatal plane for maxillary teeth, and mandibular plane for mandibular teeth. The data were analyzed by paired t-test. In this study, occlusal plane showed the significant anterior downward steepening after active treatment, and remained during retention period. In the nonextraction group, maxillary incisors were retracted and extruded during treatment. Maxillary molars were extended, and mandibular molar were uprighted, with no mesial movement. In the extraction group, both maxillary and mandibular incisors were retracted and extruded. Maxillary molars were extruded and moved mesially, and mandibular molars were extruded and moved mesially with no mesial tilting. During retention period in both groups, there were tendencies of labial tipping of maxillary incisor, and mesial tipping of maxillary and mandibular molar. But the changes were not significant and most of teeth showed no change in vortical and horizontal direction.

• Journal of Dental Rehabilitation and Applied Science
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• v.16 no.2
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• pp.93-104
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• 2000

Orthodontic treatment in conjunction with second-molar extraction has been a controversial issue among orthodontists over many decades. The aim of this study was to investigate the treatment effects of upper second molar extraction cases. The sample included 19 upper second molar extraction orthodontic cases(ten Angle's Class I's and nine Class II's, average age=13Y 6M) cared at Kyung-Hee University Department of Orthodontics. Lateral cephalometric radiographs were taken before and immediately after treatment. Seventy-nine points were digitized on each cephalogram and 38 cephalometric parameters were computed comprising 22 angular measurements, 13 linear measurements, and 3 facial proportions. The data obtained from each malocclusion group were analyzed by paired t-test. The statistical results disclosed that there was no significant change in skeletal pattern after treatment except for that accountable by growth while there was statistically significant change in dentoalveolar and soft tissue patterns. There were no significant changes in Bjork sum, posterior facial height /anterior facial height and lower anterior facial height /anterior facial height. No significant changes in anteroposterior position of maxilla and palatal plane were manifested. Although facial axis and lower facial height was slightly increased and the mandible was rotated backward and downward, there was no remarkable change in the mandibular plane. There were statistically significant changes in distal movement of upper first molar, molar key correction and overjet reduction while there was no change in the occlusal plane. The upper lip was slightly retracted simultaneously with slight increase in nasolabial angle. These results signify that distalization of upper dentition with the second molar extraction does change occlusal relationship without gross modifications in the craniofacial skeletal configurationson. Henceforth the second molar extracted would be recommended to treat severe anterior crowding and protrusion with minor skeletal discrepancy.

• Journal of the korean academy of Pediatric Dentistry
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• v.51 no.1
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• pp.99-108
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• 2024

Early loss of the primary maxillary second molar can lead to complications in which mesial drift of the adjacent first molar (M1) can disturb eruption of the succedaneous second premolar (P2). This study reports two cases of space loss for P2 caused by early exfoliation of its predecessor. After the eruption of the first premolar, the Jones jig appliance was used to distalize M1 and regain space for the eruption of P2. The appliance was further utilized to align the palatally erupted P2 into the dental arch. In both cases, the space and corrected position of P2 were well maintained. Early exfoliation of the primary second molar caused by mesial encroachment of M1 is a common phenomenon, and pediatric dentists should attend to this during routine examinations. An appropriate intervention should be initiated when the primary second molar is lost during the mixed dentition period. If used with careful anchorage control, the Jones jig appliance can effectively resolve this problem.

• Journal of Dental Rehabilitation and Applied Science
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• v.24 no.4
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• pp.371-379
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• 2008

The aim of this study was to evaluate the tightness of proximal tooth contact(TPTC) using a novel device at rest state on implant prostheses. Ten healthy young adults with class I normal occlusion consented to participate in the study and twenty patients were restored with a total 20 single-implant crowns in the left maxillary and mandibular second molars for 10 single-implant crowns, respectively. Test area were divided by 4 groups. UM describes the contact between the upper natural left first molar and natural second molar; LM the contact between the lower natural left first molar and natural second molar; IUM the contact between the upper natural left first molar and implant second molar and ILM the contact between the lower natural left first molar and implant second molar. The TPTC was measured at rest state in each area. The mean TPTC of the UM, LM, IUM and ILM was 1.48(${\pm}0.44$) N, 1.78(${\pm}0.40$) N, 1.14(${\pm}0.37$) N and 1.30(${\pm}0.32$) N respectively. These results indicate that the TPTC was less between natural tooth and implant prosthesis than between natural teeth.

• The korean journal of orthodontics
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• v.46 no.2
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• pp.96-103
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• 2016

Objective: To compare the transverse dental changes induced by the palatally applied Frog appliance and buccally applied Karad's integrated distalizing system (KIDS). Methods: We evaluated the pre- and post distalization orthodontic models of 39 patients, including 19 treated using the Frog appliance, which is palatally positioned (Frog group), and 20 treated using KIDS, which is buccally positioned (KIDS group). Changes in intermolar and interpremolar distances and the amount of maxillary premolar and molar rotation were evaluated on model photocopies. Wilcoxon and Mann-Whitney U tests were used for statistical evaluations. A p-value of < 0.05 was considered statistically significant. Results: Significant distopalatal rotation of premolars and distobuccal rotation of molars were observed in Frog group (p < 0.05), while significant distopalatal rotation of molars (p < 0.05), with no significant changes in premolars, was observed in KIDS group. The amount of second premolar and first molar rotation was significantly different between the two groups (p < 0.05 and p < 0.001, respectively). Furthermore, expansion in the region of the first molars and second premolars was significantly greater in KIDS group than in Frog group (p < 0.001 for both). Conclusions: Our results suggest that the type and amount of first molar rotation and expansion vary with the design of the distalization appliance used.

• Journal of the korean academy of Pediatric Dentistry
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• v.51 no.3
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• pp.279-289
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• 2024

This study aimed to identify the clinical characteristics of molar root-incisor malformation (MRIM) and provide clinical considerations for treatments. Panoramic radiographs and electronic medical records of 64 patients with MRIM were retrospectively reviewed. Age, gender, follow-up period, medical history, complications, distribution of MRIM teeth, treatment, and prognosis were analyzed. Females were affected 1.56 times more than males, and the average age was 8.2 years. Dental complications, including periapical lesions, abscesses, and alveolar bone loss, were observed in 71.9%, and eruption disturbance of adjacent teeth was noticed in 37.5%. Most patients had medical histories in the first year of life. The most prevalent history was prematurity or low birthweight, followed by neurological conditions, surgeries, medications, and infections. All patients had MRIM on permanent first molars. The primary second molars were the second most frequently involved, followed by maxillary permanent central incisors and primary first molars. The prevalence was low on permanent lateral incisors and canines. Extraction was the most prevalent treatment done on MRIM-affected teeth, and most extraction sockets were managed by the eruption of permanent second molars. Few cases received endodontic treatment but with low success rates. Early detection of MRIM and prompt, appropriate treatment are important to avoid unnecessary discomfort from complications.

• The korean journal of orthodontics
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• v.22 no.3 s.38
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• pp.579-589
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• 1992

Non-steroidal anti-inflammatory agents are used to relieve pain and to reduce swelling in dental clinics. This experiment was performed to study the effect of non-steroidal anti-inflammatory agents in Sprague-Dawley rats on orthodontic tooth movement. Thirty rats were used and divided six groups of five rats each. The first group, administered saline and no orthodontic force, served as a normal group. The second group, administered saline and applied experimental force, was control group. The other four groups were administered Aspirin, Pontal, Tyrenol and Indomethacin each, and applied experimental orthodontic force by 1/4 inch elastic, inserted into the interproximal space between maxillary first and second molar in rats. All experimental rats were sacrificed after three days, and the specimens were sectioned horizontally five times serially, and counted the number of osteoclasts appeared at the compressed surface of interradicular bone on first buccal root of first molar on light microscope. The obtained results were as follows: 1. The number of osteoclast on the compressed surface of the interradicular bone on first buccal root of the first molar in the four non-steroidal anti-inflammatory agents groups decreased in contrast to control group. 2. In non-steroidal anti-inflammatory agents group, the number of osteoclast in Indomethacin group was least among the all non-steroidal anti-inflammatory agents groups. From the above results, it was believed that the non-steroidal anti-inflammatory agents may have the inhibitory effect of tooth movement during orthodontic treatment.

• The korean journal of orthodontics
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• v.44 no.2
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• pp.77-87
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• 2014

Objectives: This study was designed to define the Korean norm values for the Ricketts analysis. Methods: In this longitudinal study, lateral cephalograms of 31 subjects with normal occlusion were taken biennially from ages 9-19 years. Cephalometric measurements were performed. Parameters for which the 10-year change did not exceed one standard deviation were defined as unchanged. The means and standard deviations for the measured parameters were determined for each age group. Results: No significant changes in growth were observed in the molar relationship, incisor overjet, incisor overbite, mandibular incisor extrusion, interincisor angle, lower incisor tip (B1) to A point-Pogonion (A-PO) plane, upper incisor tip (A1) to A-PO plane, B1 inclination to A-PO, A1 inclination to A-PO, B1 inclination to Frankfurt plane (FH), convexity, lower facial height, facial axis, maxillary depth, maxillary height, palatal plane to FH, cranial deflection, ramus Xi position, or porion location. Continual changes over the 10 years of growth were observed in the maxillary first molar distal position to pterygoid true vertical plane, facial depth, mandibular plane to FH, anterior cranial length, mandibular arc, and corpus length. Conclusions: Clinicians can apply the Korean norms at age 9 as determined in this study when using the Ricketts analysis. The patient's age at the beginning of treatment and their sex should be taken into consideration when drawing visual treatment objectives.