• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.35 no.4
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• pp.221-228
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• 2009

The purpose of the study was to investigate the characteristics of the pronunciation of Korean vowels in patients with class III malocclusion. 11 adult male patients with class III malocclusion(mean ages 22.3 years) and four adult males with normal occlusion(mean ages 26.5 years) were selected for the analysis of eight Korean monophthongs /ㅣ, ㅔ, ㅐ, ㅏ, ㅓ, ㅗ, ㅡ, ㅜ/. The values and relationships of F1, F2 and F3 were derived from the stable section of target vowel in each sentence, and the analysis using formant plots and vowel triangles' distance and area was conducted to find the features of two groups' vowel distributions. Consequently, it was identified that the pronunciation of males patients with class III malocclusion showed high values of F1 in the low vowels, high values of F2 in the back vowels, and remarkably low position of /ㅏ/. The vowel triangle suggested that the triangle areas of male patients with class III malocclusion were shown wider vertically and narrower horizontally than those of males with normal occlusion. These characteristics could reflect the structural features of class III malocclusion such as the prognathic mandible, low tongue position, and advancement of back position of the tongue.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.4 no.1
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• pp.23-36
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• 1995

The purpose of this artic1e is to compare soft tissue profiles between Korean adults with normal occ1usion and malocclusin and to identify the differences between them. The subjects of this cephalometric study were 40 males with normal occlusion(Group 1), 27 females with normal occlusion(Group 2), 28 adults with Angle's Class II malocclusion(Group 3) and 41 adults with Angle's Class III malocclusion(Group 4). The results of this study were as follows ; 1) People with Angle's Class II malocclusion had tendency to have more labial tipping of lower teeth than people with normal occ1usion. Through NOA angle measurement, it was determined that people with Angle's Class II malocclusion had more protruding midface than people with normal occlusion and people with Angle's Class III malocclusion had retruding midface. 2) Through Powell's esthetic triangle analysis, it was determined that people with Angle's Class II malocclusion had retruding chin and protruding nose. 3) No significant differences between people with normal occlusion and maloclusion could be identified by measuring soft tissue profile angle basis of S-NS plane. 4) There were significant differences between groups with normal occlusion and malocclusion by measuring Facial convexity angle(Significance level 99%). 5) By measuring the distance between each landmark basis of N-Pog plane, People with Angle's Class II malocclusion were identified as having more protruding midface, but there were no significant differences between people with normal occlusion and Angle's Class III malocclusion. 6) By measuring the vertical dimension of the face, it was determined that the lower facial height was higher than the upper facial height in all groups, particularly in group with Angle's Class III malocclusion. 7) By measuring the lips basis of E-line and S-line, it was determined that people with Angle's Class III malocclusion had more, protruding lower lips than people with normal occlusion, while people with normal occlusion, while people with Angle's Class II malocclusion had more protruding upper lips. By measuring the distance between the superior sulcus and inferior sulcus basis of H-line, people with Angle's Class II malocclusion had thicker upper lips than the other's.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.37
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• pp.25.1-25.9
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• 2015

Background: During the orthognathic surgery, it is important to know the exact anatomical location of the mandibular foramen to achieve successful anesthesia of inferior alveolar nerve and to prevent damage to the nerves and vessels supplying the mandible. Methods: Cone-beam computed tomography (CBCT) was used to determine the location of the mandibular foramen in 100 patients: 30 patients with normal occlusion (13 men, 17 women), 40 patients with skeletal class II malocclusion (15 men, 25 women), 30 patients with skeletal class III malocclusion (17 men, 13 women). Results: The distance from the anterior border of the mandibular ramus to mandibular foramen did not differ significantly among the three groups, but in the group with skeletal class III malocclusion, this distance was an average of $1.43{\pm}1.95mm$ longer in the men than in the women (p < 0.05). In the skeletal class III malocclusion group, the mandibular foramen was higher than in the other two groups and was an average of $1.85{\pm}3.23mm$ higher in the men than in the women for all three groups combined (p < 0.05). The diameter of the ramus did not differ significantly among the three groups but was an average of $1.03{\pm}2.58mm$ wider in the men than in the women for all three groups combined (p < 0.05). In the skeletal class III malocclusion group, the ramus was longer than in the other groups and was an average of $7.9{\pm}3.66mm$ longer in the men than women. Conclusions: The location of the mandibular foramen was higher in the skeletal class III malocclusion group than in the other two groups, possibly because the ramus itself was longer in this group. This information should improve the success rate for inferior alveolar nerve anesthesia and decrease the complications that attend orthognathic surgery.

• Journal of the korean academy of Pediatric Dentistry
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• v.42 no.2
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• pp.144-150
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• 2015

Early treatment is recommended for class III malocclusion in the primary dentition, though it is difficult to diagnose correctly. It was recommended dental maturation can possibly be used to make a differential diagnosis of skeletal class III malocclusion. This study aimed to compare dental maturation of first molars in children with skeletal or non-skeletal class III malocclusion in the primary dentition and to determine if dental maturation could be used to make a differential diagnosis of class III malocclusion. Among the children visiting the department of pediatric dentistry in Pusan National University Dental Hospital for anterior crossbite in the primary dentition, 18 were categorized into the non-skeletal class III malocclusion and 34 into the skeletal class III malocclusion. Panoramic radiographs were used to make comparative analysis of dental age and the eruption rate of the first molars. The following results were obtained. No difference was found between chronologic and dental age by the skeletal features or gender, with the latter being older than the former (p < 0.05). The discrepancies in eruption rate of first molars were significantly different between skeletal (18.91%) and non-skeletal groups (16.53%) (p < 0.05). This result implies that maturation of the first molars might be used to make a differential diagnosis of class III malocclusion.

• The korean journal of orthodontics
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• v.24 no.2
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• pp.395-403
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• 1994

To find out the antero-posterior morphology of the upper face in Angle's class III malocclusion patients, 90 patients, adults in Heilman's Dental age, were used as samples and following results were obtained after the relative comparision of antero-posterior relationship of upper facial structures between Angle's class I malocclusion patients and Angle's class III malocclusion patients and of antero-posterior size of upper facial structures to horizontal and vertical structures in each patients. 1. After comparison of the distance from PMV line to anterior margin of maxillary sinus and cheek, which determines the antero-posterior position of the upper face, upper face in Angle's class III patients are underdeveloped relative to Angle's class I patients. The distance between orbitale and anterior margin of maxillary sinus were greater in Angle's class I patients, whic implies thart the upper face in Angle's class III are depressed. 2. Antero-posterior dimension of anterior cranial base from PMV line and vertical dimension of upper face are statistically insignificant between two groups. After comparing antero-posterior position of upper face to anterior cranial base, the upper face in Angle's class Et patients are depressed antero-posteriorly in relation to anterior cranial base. Following the comparision of antero-posterior position of upper face in relation to vertical dimension of upper face, the upper face in Angle's class III patients seem to be narrow antero-posteriorly

• Journal of Technologic Dentistry
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• v.29 no.2
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• pp.197-211
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• 2007

With the development of orthodontics and increasing concerns on physical appearance, the number of patients has been steadily increasing. It is quite important not only to make effective cure plans and accurate diagnoses but also to have a thorough grasp of patients' malocclusion types and their occurrence frequency, in addition to patients' personality in order to cure the patients appropriately. This study is based on 946 malocclusion patients who had visited Chong-A Dental Hospital from 1999 to 2004 and investigated their aspects of malocclusion and characteristics of their gender, age and residence. The results are as follows. 1. The number of patients per year had been decreased until 2001, after which year the number had fluctuated. The number was the largest in 1999, 169 and the smallest in 2001, 140. Female occupied 68.0% of the total, twice as many as male, 32.0%) 2. Based on the Angle's classification, 19 or over year - old group was the largest of the total, 59.3% and 6 or younger year - old group, the smallest, 0.5%. The 19 or over year old group was less than a half of the total (47.4%) in 2003 and there were no patients who belonged to the 6 or younger year - old group in 2003 and 2004. 3. Distributions on the types of malocclusion have shown that 39.9 % of the total are in the Class I, the largest, 31.0% in the Class I and 29.2 in the Class II, the smallest. 1) The number of the ClassI was 73, the largest, that of the Class III being 35, the smallest in 1999. On the whole, the number of the Class I accounted for the largest part of the total. 2) The number of male patients in the Class II was the smallest, generally being the largest in the Class I. In case of female, that of the Class III was the smallest. 3) Based on the age, the Class I was the highest in between 7 and 13 age group, the Class III the lowest. The Class I occupied the largest around 40%. 4) In the shape of physiognomy, the meso occupied the largest part among all the Class, of which the Class II was the highest, 64.2%. The bracy was the largest in the Class I, and the dolicho in the Class III. 5) In the profile, the convex shape was the largest in the Class I and II, and especially in the Class II, over 3/4 of the total, 75.4%. In contrast, the direct shape was the largest in the Class III and the sunken shape occupied 33.3%, which was nearly ten times more than the case of the Class I and III. 6) In the asymmetry of physiognomy, the number of patients of the Class IIIwas the largest, 34.1% and that of the Class II, the smallest, 19.5%. It was found that about one fourth of the malocclusion patients were under the asymmetry of physiognomy. 4. In the distribution of patients' residence, 81.4% were from the Seoul Metropolis and 48.2% from Gangnam-Gu where Chong-A Dental Hospital is located and Seocho-Gu and Songpa-Gu which are adjacent to Gangnam-Gu.

• Journal of the korean academy of Pediatric Dentistry
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• v.23 no.2
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• pp.537-548
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• 1996

To investigate the relationship between the calcification stages of mandibular canines and the skeletal maturity stage of the hand-wrist in subjects with normal occlusion and Class III malocclusion, hand-wrist radiographs and panoramic radiographs were taken from subjects of normal occlusions(94 males, 88 females) and Class III malocclusions(75 males, 76 females) who had no systemic diseases and no history of orthodontic or prosthodontic treatment. Fishman's method for the skeletal maturity stages of the hand-wrist and Demirijian's method for the calcification stages of mandibular canines were used and analyzed. The results were as follows : 1. In subjects with normal occlusion and Class III malocclusion, skeletal maturity of the hand-wrist and calcification of mandibular canines at various ages occured earlier in females than in males(p<0.05). 2. Comparing the skeletal maturity stages of the hand-wrist and the calcification stages of mandibular canines between subjects with normal occlusion and Class III malocclusion, there were no significant differences between the groups. 3. The correlation coefficient between the calcification stages of mandibular canines and the skeletal maturity stages of the hand-wrist. in subjects with normal occlusion and Class III malocclusion showed a high association(p<0.01). 4. In stage 4 of the skeletal maturity of the hand-wrist, the frequency distribution of calcification G stage among the various calcification stages was highest both in normal occlusion and in subjects with Class III malocclusion. However, there was no significant difference in the frequency distribution of calcification stages between the groups.

• Maxillofacial Plastic and Reconstructive Surgery
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• v.39
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• pp.22.1-22.9
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• 2017

Background: Two-jaw surgery including mandibular and maxillary backward movement procedures are commonly performed to correct class III malocclusion. Bimaxillary surgery can reposition the maxillofacial bone together with soft tissue, such as the soft palate and the tongue base. We analyzed changes of pharyngeal airway narrowing to ascertain clinical correlations with the prevalence of snoring after two-jaw surgery. Methods: A prospective clinical study was designed including a survey on snoring and three-dimensional (3D) computed tomography (CT) in class III malocclusion subjects before and after bimaxillary surgery. We conducted an analysis on changes of the posterior pharyngeal space find out clinical correlations with the prevalence of snoring. Results: Among 67 subjects, 12 subjects complained about snoring 5 weeks after the surgical correction, and examining the 12 subjects after 6 months, 6 patients complained about the snoring. The current findings demonstrated the attenuation of the largest transverse width (LTW), anteroposterior length (APL), and cross-sectional area (CSA) following bimaxillary surgery given to class III malocclusion patients, particularly at the retropalatal level. The average distance of maxillary posterior movements were measured to be relatively higher (horizontal distance 3.9 mm, vertical distance 2.6 mm) in case of new snorers. Conclusions: This study found that bimaxillary surgery could lead to the narrowing of upper airway at the retropalatal or retroglossal level as well as triggering snoring in subjects with class III malocclusion. Based on the current clinical findings, we also found that upper airway narrowing at retropalatal level may contribute to increasing the probability of snoring and that polysonography may need to be performed before orthognathic surgery in subjects with class III malocclusion.

• The Journal of the Korean dental association
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• v.50 no.2
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• pp.64-71
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• 2012

Recently, the presurgical orthodontic duration tends to be shortened by virtue of the advancement of surgical and orthodontic techniques in class III orthognathic surgery cases. But the predictability of the surgical results should be secured by removing several uncertain factors in presurgical orthodontic treatment. The purpose of this study is to investigate the influence of immediate postsurgical occlusal stability on postsurgical mandibular change. The study includes 40 patients who underwent orthognathic surgery to correct skeletal class III malocclusion. The patients were divided into two groups based on the numbers of occlusal contact in surgical setup occlusion: group 1 (stable surgical occlusion, n=24) and group 2(unstable surgical occlusion, n=16). Changes of horizontal and vertical mandibular measurements during postsurgical follow up period(from 1 week postsurgery to 12month after debonding) were compared to examine the differences between two groups. The stability of surgical occlusion is one of the factors influencing postsurgical mandibular changes in class III malocclusion. The various class III malocclusion cases have specific prerequisites for the orthognathic surgery according to the skeletal patterns. The prerequisites should be obtained by minimum presurgical orthodontics to increase the predictability of the surgical results.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.787-798
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• 1994

The purpose of this study was three-fold: i) to investigate the degree of asymmetry in Angle's Class III malocclusion patients and normal adults; ii) to determine the nature of difference existed between two groups; and iii) to investigate the correlationship between the degree of asymmetry and ANB and overbite in Angle's Class III malocclusion patients. The subjects consisted of 25 Angle's Class III malocclusion patients and 25 normal adults and the mean ages were 22.0 and 24.5 years, respectively. Their posteroanterior and lateral cephalograms were traced and analysed with three-dimensional approach. The results were as follows: 1. Asymmetry of Angle's Class III malocclusion group was significant in all regions except cranial base. Their horizontal asymmetry was seen in mandibular angle, maxillary and mandibular 1st molar, mandibular midline and menton. Vertical asymmetry was observed in maxillary 1st molar and mandibular shape and anteroposterior asymmetry in mandibular angle. 2. Nine variables indicating asymmetry were selected and each variable had similar discriminant score. 3. There was a little correlationship between An and asymmetric variable(MSR-B6) and its correlation coefficients was 0.3564. 4. There was no significant correlationship between overbite and asymmetric variables.