• The korean journal of orthodontics
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• v.39 no.5
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• pp.330-336
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• 2009

Objective: To examine the differences in lateral cephalometric characteristics between patients with dental protrusion and crowding in order to determine what factors affect dental protrusion or crowding while both malocclusion types are caused by large tooth size. Methods: Twenty nine individuals with dental protrusion and 22 individuals with dental crowding were enrolled in this study. All subjects had larger teeth than average and Class I molar relationships. Craniofacial characteristics and hyoid bone positions were determined from lateral cephalograms and compared between the two groups. Results: In the comparisons of craniofacial characteristics, the measurements indicating maxillary length and facial convexity showed greater values in the protrusion group than in the crowding group. Comparisons of hyoid bone positions showed that the hyoid bone was positioned more anteriorly and superiorly in the protrusion group than in the crowding group. Conclusions: The results of the present study indicate that some craniofacial characteristics and tongue position may affect the development of dental protrusion or crowding; when an individual has large teeth, dental protrusion or crowding might be determined according to maxillary growth and tongue position.

• The korean journal of orthodontics
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• v.44 no.5
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• pp.236-245
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• 2014

Objective: To evaluate the therapeutic effects of a preformed assembly of nickel-titanium (NiTi) and stainless steel (SS) archwires (preformed C-wire) combined with temporary skeletal anchorage devices (TSADs) as the sole source of anchorage and to compare these effects with those of a SS version of C-wire (conventional C-wire) for en-masse retraction. Methods: Thirty-one adult female patients with skeletal Class I or II dentoalveolar protrusion, mild-to-moderate anterior crowding (3.0-6.0 mm), and stable Class I posterior occlusion were divided into conventional (n = 15) and preformed (n = 16) C-wire groups. All subjects underwent first premolar extractions and en-masse retraction with preadjusted edgewise anterior brackets, the assigned C-wire, and maxillary C-tubes or C-implants; bonded mesh-tube appliances were used in the mandibular dentition. Differences in pretreatment and post-retraction measurements of skeletal, dental, and soft-tissue cephalometric variables were statistically analyzed. Results: Both groups showed full retraction of the maxillary anterior teeth by controlled tipping and space closure without altered posterior occlusion. However, the preformed C-wire group had a shorter retraction period (by 3.2 months). Furthermore, the maxillary molars in this group showed no significant mesialization, mesial tipping, or extrusion; some mesialization and mesial tipping occurred in the conventional C-wire group. Conclusions: Preformed C-wires combined with maxillary TSADs enable simultaneous leveling and space closure from the beginning of the treatment without maxillary posterior bonding. This allows for faster treatment of dentoalveolar protrusion without unwanted side effects, when compared with conventional C-wire, evidencing its clinical expediency.

• Imaging Science in Dentistry
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• v.39 no.2
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• pp.69-73
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• 2009

Purpose: This study compared panoramic radiography and cone beam computed tomography (CBCT) for evaluating the relationship between the maxillary sinus floor and the roots of maxillary molars. Materials and Methods: Paired panoramic radiographs and CBCT images from 97 subjects were analysed. This analysis classified 388 maxillary molars according to their relationship to the maxillary sinus floor on panoramic radiograph and CBCT. Correlations between these two radiographic techniques were examined. Results: Maxillary molar roots that were separate from the sinus floor showed the same classification in 100% of the cases when using these two imaging techniques. The corresponding percentage for such roots that were in contact with the sinus floor was 75%. When roots overlapped the maxillary sinus floor on panoramic radiographs, only 26.4% of maxillary first molars and 60.0% of second molars showed protrusion of roots into the sinus with CBCT. Conclusion : The results of the study suggest that roots projecting into the sinus on panoramic radiographs require a three-dimensional image in order to analyze the proximity of their apex to the sinus floor. (Korean J Oral Maxillofac Radiol2009; 39 : 69-73)

• The korean journal of orthodontics
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• v.29 no.2 s.73
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• pp.147-156
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• 1999

Skeletal Cl III malocclusion is an orthopedic appliance mainly used for growing children with maxillary undergrowth, which largely entails skeletal Cl III malocclusion. It improves anterior crossbite and maxillary position and thus, enables patients to attain favorable Profile but often involves unfavorable profile with protrusive upper and lower lips. Therefore, if orthodontists have knowledge of which condition helps obtain favorable occlusion and profile, they are able to predict the prognosis and limitation of the treatment. This study was done in order to help obtain favorable Profile after treating growing skeletal Cl III children. In the study, we classified childern into two groups, the one with favorable profile(Group 1, n=12) and the other with unfavorable profile(Group 2, n=14) and, with retrospective study using pre- and post-treatment lateral cephalogram, drew the following conclusions. 1. As patients had more serious labioversion of upper incisors, they were more unlikely to have favorable profiles after the treatment. Protrusion of prosthion, which was related with maxillary incisors, also affected profiles. 2. As the NL-ML angle before the treatment was small, it was more likely to get favorable profile. 3. As the degree of lower lip protrusion was high, it was likely to have bialveolar protrusion after the treatment. 4. As the degree of downward and backward rotation of mandible was high, it was likely to get unfavorable profile.

• Journal of Technologic Dentistry
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• v.35 no.3
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• pp.231-242
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• 2013

Purpose: The study is to discover the relationship between malocclusion, which is known to cause temporomandibular disorder, and temporomandibular disorder and is aimed at college students who have retained their natural teeth. Methods: The study was aimed at 500 college students at two colleges located in Gyeongsangbuk-do and Daegu metropolitan city and survey research was conducted in order to discover any relationship between malocclusion and temporomandibular disorder. After excluding copies with insincere answers or errors out of the 500 copies of the questionnaire, the study used a total of 435 copies (87%) for research and analysis. Results: Females showed a prevalence of temporomandibular joint clicking and temporomandibular joint pain, and students who had crowding showed a high prevalence of temporomandibular joint pain, temporomandibular joint clicking, and trismus. Students whose occlusal condition was not good demonstrated a high prevalence of temporomandibular joint pain, temporomandibular joint clicking, and trismus. Students who had maxillary protrusion showed a prevalence of temporomandibular joint clicking and trimus, whereas students who had mandibular protrusion showed a high prevalence of temporomandibular joint clicking. Conclusion: Students whose dental condition was crowding and students whose occlusal condition was not good exhibited a high prevalence of three types of symptoms of temporomandibular disorder. Meanwhile student who had maxillary protrusion showed a high prevalence of temporomandibular joint clicking and trismus, while students who had mandibular protrusion showed a prevalence of temporomandibular joint clicking.

• The Journal of the Korean dental association
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• v.55 no.12
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• pp.850-860
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• 2017

Orthodontic treatment with premolar extraction is usually performed to correct bialveolar protrusion. These methods require the use of stiff rectangular working archwire which requires lengthy alignment and leveling before insertion. In this case report, interproximal reproximation was performed instead of extraction. To establish clearance between the archwire and resin domes fixing the archwire, an archwire was inserted into a water-soluble tube before fabricating resin domes. This tube is solved away by the saliva. During fabrication of resin domes, the archwire was deflected intentionally reflecting the displacement of teeth from their ideal position. This can be called as deflection-based bonding (DBB) technique. DBB is different from conventional method of positioning the brackets on its ideal position and then inserting an archwire to align the brackets. Because the orthodontic force of the archwire comes from its deflection from passive configuration, deflecting an archwire as needed can move the teeth more predictably than just bonding brackets on its ideal position. Also, areas with good alignment before orthodontic treatment can be maintained simply by not deflecting the archwire during bonding in these areas. After initial alignment, interproximal reproximation was performed to create 4.8 mm space in the maxillary arch and 4.2 mm space in the mandibular arch. These spaces were closed using orthodontic mini-implant anchorage thus retracting the maxillary incisors 4 mm posteriorly accompanied with 0.7 mm and 0.3 mm distal movement of right and left molars. By using interproximal reproximation and water-soluble tube with DBB, mild bialveolar protrusion was successfully treated without extraction.

• Journal of dental hygiene science
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• v.23 no.2
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• pp.112-122
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• 2023

Background: This study aimed to evaluate the effect of a prefabricated functional appliance (Myobrace^®) on skeletal, dental, and soft tissue components in children with Class II, division 1 malocclusion. Methods: Thirteen patients with Class II, division 1 malocclusion (9 girls and 4 boys; mean age, 8.2±0.9 years at the start and 9.3±1.0 years at the end of the treatment) were treated with Myobrace^® for a mean period of 12.9±4.0 months. Patients were instructed to use the appliance daily for 1 hour and overnight while sleeping. A control group of 10 patients with untreated Class II, division 1 malocclusion (3 girls and 7 boys; mean age, 9.0±1.6 years at the start and 10.4±2.1 years at the end of the observation) was included to eliminate possible growth effects. The mean observation period for this group was 17.7±11.2 months. Lateral cephalograms were taken at the start and end of the treatment, and findings from 41 measurements were analyzed using the V-Ceph^TM program. The mean and standard deviation of cephalometric measurements were analyzed using paired and independent sample t-tests. Results: The treatment group showed significant changes in SNB, ANB, maxillary protrusion, ramus height, proclination of upper anterior teeth, interincisal angle, overjet, and upper lip protrusion compared with the control group. However, only decrease in ANB, maxillary protrusion, overjet, upper lip protrusion, and increase in interincisal angle were significantly higher in the treatment group than in the control group. Conclusion: The prefabricated functional appliance induced skeletal, dentoalveolar, and soft tissue changes, resulting in a significant reduction in anteroposterior discrepancy.

• The Journal of the Korean dental association
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• v.41 no.10 s.413
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• pp.720-727
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• 2003

Clinicians generally agree that Class III malocclusion is one of the most difficult to treat. When the Class III malocclusion is characterized by maxillary retrusion in growing patients, the use of a face mask may be the treatment of choice. Although face mask can achieve excellent orthopedic effects. It demands special patient compliance because it is worn extraorally and is not as esthetic or comfortable as intraoral appliance. This report presents the clinical cases of mandibular protrusion correction in growing patients, who were treated by TTBA(Tandem Traction Bow Appliance) that's a intraoral appliance.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.40 no.2
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• pp.87-90
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• 2014

The present report describes the case of a patient who underwent maxillary sinusitis right after dental implant installation with sinus lifting. Computed tomography scan revealed a dental implant (#16) was protruded inside the right maxillary sinus and confirmed the obstruction of ostium. A symptom remission was gained with the dual approaches combined by functional endoscopic sinus surgery and an intra-oral approach. Fully recovered function and healing of sinus were identified after 10 months follow-up. We report the case of sinusitis caused by protrusion of implants with sinus floor lift procedures and propose that practitioners should be aware of the possible its complications and management.

• Journal of Korean Academy of Oral and Maxillofacial Radiology
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• v.14 no.1
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• pp.39-50
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• 1984

The aim of this study was to evaluate the dentofacial relationship of the Korean adult females who had excellent profile using roentgenocephalometry. The subjects were 35 females from 19 to 24 years of age selected among the professional models, beauty contest winners and performing stars. And, as the control group, 37 females from 18 to 23 years of age with normal occlusion and acceptable profile were selected. In both groups, each variable was measured and evaluated statistically introducing 24 reference points, 22 reference lines and 17 reference angles respectively. Conclusions from this study were as follows; 1. There was no significant difference between the two groups. But SNA and convexity angle which had indicated the maxillary protrusion were lesser in the professional models, beauty contest winners and performing stars than in ~he control group. 2. In the professional models, beauty contest winners and performing stars, the maxillary and mandibular incisors were more upright than in the control group. 3. The protrusion of the upper and lower lip was lesser in the professional models, beauty contest winners and performing stars than in the control group. 4. Professional models, beauty contest winners and performing stars revealed more straight profile than the control group and were similar to that of the Caucasian. 5. Generally, it was the tendency that the straight profile was accepted as esthetics.