• 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.36 no.1 s.114
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• pp.45-54
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• 2006

Recent beauty trends have caused an increase in the number of bialveolar protrusion patients seeking treatment of lip protrusion. But studies of these patients are not common. Studies using their dental models are especially rare. Dental models have been measured manually or through a computer by digitizing two dimensional images of models. Nowadays, we are able to study dental models more easily and accurately by utilizing the three-dimensional (3-D) laser scanner in dentistry. An investigation was carried out to evaluate the characteristics of the dental arch in a bialveolar protrusion group in comparison with a normal group using 3-D digital models. The normal group was composed of 20 subjects who were selected from students of the School of Dentistry, Kyungpook National University. The bialveolar protrusion group was composed of 20 subjects who visited for treatment at the Department of Orthodontics, Kyungpook National University Hospital. Tooth size, arch width and arch length were measured digitally, and arch shape and the shape of the palate were drawn. Based on the results of this study, the differences of the arch characteristics in the bialveolar protrusion group were that the size of the teeth was larger, mandibular canine width and 1st premolar width were wider, and arch length was longer than in the normal group. And there were differences in the arch shape and the shape of palate between the bialveolar protrusion and normal groups.

• Journal of Korean Dental Science
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• v.6 no.2
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• pp.78-86
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• 2013

Purpose: The purpose of this study was to assess the effects of lip anteroposterior position based on esthetic line on the perceived attractiveness. Materials and Methods: We selected a 20s female standard lateral photograph which was within average range of cephalometric analysis, modified lips anteroposterior position based on esthetic line into 5 pictures. This study investigated and compared the preference of facial profile among the groups; male : female and dental relevance: non-dental relevance. Total 255 judges (male : female=138 : 117, relevant : non-relevant=159 : 96) who were 20s to 30s were asked to rate these photographs based in lip attractiveness using visual analogue scale (VAS). Result: All groups had similarity the average of VAS of moved backward lips 2 mm were highest and moved forward lips 4 mm were lowest. Comparing between male group and female group, there were significant differences in all pictures except for original which was not modified. In the dental groups, moved forward lips 2 mm had significant difference and the average in dental relevant group were lower than non-relevant group in lip protrusion. Conclusion: The preference about lip protrusion was similar irrespective of dental knowledge or gender. All groups preferred retrusion of lips to protrusion of lips. In female group, they had higher the average of VAS. In relevant group, they disliked protrusion rather than retrusion of lips significantly.

• 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.33 no.7 s.314
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• pp.462-463
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• 1995

• The Journal of the Korean dental association
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• v.15 no.3
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• pp.199-204
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• 1977

The patient, 19 years old female, complained of protrusion of upper and lower anterior teeth. Teeth lining was good except slight crowding in lower anterior teeth. Teeth lining was good except slight crowding in lower incisors, but distocclusion in the region of right buccal segment was present. Cephalometric analysis revealed normal relation between maxilla and cranial base. The labial inclination of upper and lower anterior teeth was severe, so diagnosed as bialveolar protrusion case. She was treated by means of multibanded system under the extraction of four first bicuspids. After 1 year and 4 months. She gained good interdigitation of buccal segments and attractive facial profile because the labioversion of incisors was reduced properly.

• The Journal of the Korean dental association
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• v.23 no.11 s.198
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• pp.979-986
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• 1985

This is a case report of orthognathic surgery for the correction of maxillary retrusion and mandibular protrusion. The summary and results are as follows, 1. The maxillary retrusion was corrected by LeFort I osteotomy. 2. The mandibular protrusion was corrected by sagittal split osteotomies in the rami. 3. And, for the correction of the discrepancy between max8llary and mandibular arches, the mandibular arch was widened by the midsymphyseal step osteotomy. 4. The ratios of horizontal changes of soft tissue to hard tissue at the points, Subnasale (Sn), Labrale superius (Ls), Labrale inferius (L9), and Supramentale (B) were 67.6%, 43.2$, 70.2% and 87.7%, respectively.

• 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.

• The korean journal of orthodontics
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• v.48 no.3
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• pp.189-199
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• 2018

For patients with bimaxillary protrusion, significant retraction and intrusion of the anterior teeth are sometimes essential to improve the facial profile. However, severe root resorption of the maxillary incisors occasionally occurs after treatment because of various factors. For instance, it has been reported that approximation or invasion of the incisive canal by the anterior tooth roots during retraction may cause apical root damage. Thus, determination of the position of the maxillary incisors is key for orthodontic diagnosis and treatment planning in such cases. Cone-beam computed tomography (CBCT) may be useful for simulating the post-treatment position of the maxillary incisors and surrounding structures in order to ensure safe teeth movement. Here, we present a case of Class II malocclusion with bimaxillary protrusion, wherein apical root damage due to treatment was minimized by pretreatment evaluation of the anatomical structures and simulation of the maxillary central incisor movement using CBCT. Considerable retraction and intrusion of the maxillary incisors, which resulted in a significant improvement in the facial profile and smile, were achieved without severe root resorption. Our findings suggest that CBCT-based diagnosis and treatment simulation may facilitate safe and dynamic orthodontic tooth movement, particularly in patients requiring maximum anterior tooth retraction.

• 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.