• The Journal of Korean Academy of Prosthodontics
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• v.29 no.3
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• pp.43-53
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• 1991

It is important to harmonize the occlusion with TMJ and neuromuscular system. However, clinically, how to harmonize is very difficult. The mandibular movement is the motion in which all component part of stomatognathic system participate. This study was performed to compare mandibular movement of mandibular prognathic patients group with that of normal group, to ascertain which components of mandibular movement have differences between two groups, and to use for occlusal treatment of mandibular movement. Thirteen adult who have physiologically normal occlusion and are free of TMJ dysfunction were selected as a control group(Group 1). Eight adult who are mandibular prognathic patient and have more than four anterior teeth crossbite, therefore have not anterior guidance function and have posterior interference at protrusion were selected as a experimental group(Group 2). Electronic pantograph, Denar Pantronic (Denar Corp., U.SA.), was used to record mandibular movement. Pantronic survey was performed by using an arbitrary hinge axis according to manufacturer's direction. Of the Pantronic recordings, immediate side shift (ISS), progressive side shift (PSS), orbiting condylar path (ORB), protrusive condylar path (PRO) between two groups were compared and analysed. The results were as follows: 1. The average protrusive and orbiting condylar inclination of mandibular prognathic patient$(28.44^{\circ},\;36.94^{\circ})$ was significantly lower than those of normal group$(40.15^{\circ},\;48.00^{\circ})$ (P<0.01). 2. There was no statistically significant difference between .the average immediate and progressive side shift of mandibular prognathic patient $(0.37mm,\;6.19^{\circ})$ and those of normal group$(0.52mm.\;5.96^{\circ})$ (P>0.01). 3. The significant correlation was found between orbiting condylar inclination and protrusive condylar inclination.

• Journal of the korean academy of Pediatric Dentistry
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• v.31 no.1
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• pp.46-51
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• 2004

Talon cusp is cusp-like structure that develops additionally in crown of anterior tooth. And it is one of dental anomalies. Talon cusp can cause various diagnostic, functional, aesthetic problems depending on the size and configuration of cusp. there is a tendency for caries to occur in the developmental grooves, and advanced attrition, periodontal problems, irritation the tongue and temporomandibular pain, occlusal interference and displacement of affected tooth may result. Therefore, early diagnosis and appropriate treatment of each case is important so that it minimize local problems, such as caries, periodontal diseases, and malocclusion. These cases which are in permanent and primary anterior teeth are about gradual reduction forming reparative dentine and complete reduction of talon cusp and root canal therapy which is an alternative and effective form of treatment when gradual reduction of talon cusp may not be possible.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.2
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• pp.255-260
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• 2001

Trauma to the primary incisors may cause developmental or eruptional disturbance of the permanent successors. Two cases illustrate developmental disturbances of arrested root formation, dilaceration, and eruptional disturbances of impaction, ectopic eruption of permanent successors caused by traumatic injury to deciduous incisors. The patient of the first case suffered trauma at the age of 4 years 7 months, causing alveolar bone fracture including the maxillary right primary central and lateral incisors that were immedi-ately extracted. The second patient had trauma episodes at the age of 3 years. Avulsion of the maxillary primary right central and lateral incisors were occurred due to trauma. After such trauma, regular follow-up including radiographs is necessary to detect early any possible interference with normal eruption of permanent successors.

• Journal of the korean academy of Pediatric Dentistry
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• v.25 no.1
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• pp.134-143
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• 1998

Twin Blocks are simple bite-blocks that effectively modify the occlusal inclined plane to induce favorably directed occlusal forces by causing a functional mandibular displacement. These devices use upper and lower bite-blocks that engage on occlusal inclined planes. Twin Blocks use the forces of occlusion as the functional mechanism to correct the malocclusion. To get an excellent result in the treatment by using the Twin Block appliances, proper case selection must be needed. Twin Block treatment is performed in two stages. Twin Blocks are used in the active phase to correct the anteroposterior relationship and establish the correct vertical dimension. Once this phase is accomplished, the Twin Blocks are replaced with an upper Hawley type of appliance with an anterior inclined plane, which is then used to support the corrected position as the posterior teeth settle fully into occlusion. The Twin Block is the most comfortable, the most esthetic ane the most efficient of all the functional appliances. Twin Blocks have many advantages compared to other functional appliances. Patients can wear Twin Blocks 24 hours per day and can eat comfortably with the appliances in place. From the moment Twin Blocks are fitted, the appearance is noticeably improved. There is less interference with normal function. Integration with conventional fixed appliances is simpler than with any other functional appliance. Twin Blocks allow independent control of upper and lower arch width. Appliance design is easily modified for transverse and sigittal arch development. The authors treated Class II malocclusion with Twin Blocks. and the results as follows; 1. Rapid profile improvement was achieved in 2-3 months. 2. There was excellent patient cooperation. 3. Severe overjet and overbite were reduced. 4. Class II molar relationship was changed to Class I.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.26 no.6
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• pp.628-635
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• 2000

The purpose of this study was to evaluate the result after 2-phase surgical-orthodontic treatment without preoperative orthodontic treatment for the skeletal Cl III malocclusion patient and to obtain an adequate protocol on the bases of this result. This retrospective study of ten patients who underwent 2-phase treatment were done to evaluate 1) the surgical stability and relapse pattern 2) the facial esthetics 3) the TMJ problem 4) the total time of the treatment. Results were followed : 1) The horizontal relapse of the mandible was 26.8% and didn't show significant differences compared to the conventional 3-phase treatment. But, it was considered that this amount of relapse was the sum of true relapse and autoratation of mandible due to decreased vertical dimension during orthodontic treatment. 2) It was estimated that there's no difference on the ratio of anterior facial height between the subjects and the normal patients. On the horizontal analysis, the mandible of the subjects was located more anteriorly than that of the normal patients. This result showed that there was a need for the accurate preoperative esthetic evaluation and the additional methods for reducing the relapse due to the occlusal interference. 3) Wide variation was noted on the TMJ symptoms of the subjects, however, it was estimated that there's no significant differencees of symptoms compared to that of the conventional 3-phase treatment on literatures. 4) The average of the overall period of treatment was 20.8 months and we obtained reduction of the treatment time compaired to 3-phase treatment on many literatures. Most of the results of this study were similar to the findings of the 3-phase treatment(preoperative orthodontic-orthognathic surgery-postoperative orthodontic), but total time of the treatment was shorter in patients with 2-phase treatment than in those with the conventional 3-phase treatment. With 2-phase treatment, we experienced many advantages compared to the conventional method considering that it was favarable conditions for the teeth, it had the flexibility for the treatment, and it could be the adequate treatment approach for the stomatognathic system. Although this retrospective pilot study had some limitations, due to small samples, the authors would hope that it could serve as a guide for the future researches, and the clinical applications.

• Journal of dental hygiene science
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• v.17 no.2
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• pp.116-122
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• 2017

The purpose of this study was to evaluate the detection ability of secondary caries using qunatitative light-induce fluorescence-digital (QLF-D) device. Twenty bovine teeth with cavity on surface were demineralized during 21 days for secondary caries lesion of cavity wall. After 21 days, cavity was filled using composite resin and cut the specimen in half with disc. Fluorescence loss of lesion on surface by time flow, cross sectional lesion, and lesion of filled or unfilled surface were analyzed using analysis software. ${\Delta}F$ (value of fluorescence loss) of the lesion on surface assessed by the QLF-D increased significantly over time up to 21 days. And ${\Delta}F$ value of lesion of filled surface is significantly lower than that of unfilled surface (p<0.001). ${\Delta}F$ of filled surface is 1.31 times of cross section lesion. The correlation of between ${\Delta}F$ of filled surface lesion and ${\Delta}F$ of cross section lesion was showed low agreement (0.026) and correlation of between ${\Delta}F$ of unfilled surface lesion and ${\Delta}F$ of cross section lesion was showed high agreement (0.613). In conclusion, secondary caries can be detected on surface using QLF-D. However, interference of fluorescence of filling material is the points to be especially considered for exact analysis of secondary caries lesion.

• The korean journal of orthodontics
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• v.31 no.6 s.89
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• pp.549-558
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• 2001

This study was undertaken to demonstrate the forces in the maxillary alveolar bone generated by the activation of the maxillary posterior crossbite appliance In the treatment of posterior buccal crossbite caused by buccal ectopic eruption of the maxillary second molar. A photoelastic model was fabricated using a Photoelastic material (PL-3) to simulate alveolar bone and ivory-colored resin teeth. The model was observed throughout the anterior and posterior view in a circular polariscope and recorded photographically before and after activation of the maxillary posterior crossbite appliance. The following conclusions were reached from this investigation : 1. When the traction force was applied on the palatal surface of the second molar, stresses were concentrated at the buccal and palatal root apices and alveolar crest area. The axis of rotation of palatal root was at the root apex and that of the buccal root was at the root li4 area. In this result, palatal tipping and rotating force were generated. 2. When the traction force was applied on the buccal surface of the second molar, more stresses than loading on the palatal surface were observed in the palatal and buccal root apices. Furthermore, the heavier stresses creating an intrusive force and controlled tipping force were recorded below the buccal and palatal root apices below the palatal root surface. In addition, the axis of rotation of palatal root disappeared whereas the rotation axis of the buccal root moved to the root apex from the apical 1/4 area. 3. When the traction force was simultaneously applied on the maxillary right and left second molars, the stress intensity around the maxillary first molar root area was greater than the stress generated by the only buccal traction of the maxillary right or left second molar. As in above mentioned results, we should realize that force application on the palatal surface of second molars with the maxillary posterior crossbite appliance Produced rotation of the second molar and palatal traction, which nay cause occlusal Interference. That is to say, we have to escape the rotation and uncontrolled tipping creating occlusal interference when correcting buccal posterior crossbite. For this purpose, we recommend buccal traction rather than palatal traction force on the second molar.

• Journal of the korean academy of Pediatric Dentistry
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• v.32 no.4
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• pp.595-603
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• 2005

Incomplete removal of bacteria contaminated dentin or enamel associated with caries is a potential problem in restorative dentistry Secondary or residual caries, pulpal inflammation and hypersensitivity may result from bacteria left after the initial preparation, especially if an adequate seal against microleakage is not obtained. A possible solution to eliminate residual bacteria left in a cavity preparation would be to treat the cavity with cavity disinfectant wash. But a potential problem with using a cavity disinfectant with dentin bonding agents could be their interference with the ability of the resin to bond to the tooth micromechanically. The purpose of this study was to evaluate the effect of 2% chlorhexidine containing cavity disinfectant ($Consepsis^{(R)}$) on shear bond strength and microleakage of dentin bonding agents, $Adper ^{TM}$ $Scotchbond^{TM}$ Multi-Purpose, $Adper^{TM}$ Single Bond and $Adper^{TM}\;Prompt^{TM}\; L-Pop^{TM}$ Sixty and sixty sound human third molar teeth, respectively, were used for shear bond strength and microleakage test. For experimental group, cavity disinfectant was applied before dentin bonding agents, and was not applied for the control group. The result from the this study can be summarized as follows ; 1. Use of 2% chlorhexidine containing cavity disinfectant($Consepsis^{(R)}$) does not significantly affect the shear bond strength of dentin bonding agents. 2. Use of 2% chlorhexidine containing cavity disinfectant($Consepsis^{(R)}$) does not significantly affect the microleakage of dentin bonding agents.