• Korean Journal of Cleft Lip And Palate
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• v.5 no.1
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• pp.27-42
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• 2002

This study was designed to evaluate the morphology and the position of the mandible in the complete unilateral cleft lip and palate patients, Craniofacial skeletal morphology pattern was analyzed on the lateral cephalometric radiographs of the 50 subjects of complete unilateral cleft lip and palate, the 50 normal and 50 class III, Each group was divided into child and adult sub-groups, All the data were tested statistically. The results were as follows: I, In the comparison with the normal group, complete cleft group showed smaller angular, condylar length, clockwisely rotated mandible and larger NMe/SGo(p<0.01). 2, In the comparison with the class III group, the complete cleft group showed significantly smaller angular, condylar, ramal, body length of the mandible(p<0,01). 3. As for the position of the mandibular condyle to the cranial base, the class III group was the most anterior, the normal group was the most posterior and the complete cleft group was in the middle(p<0.05). 4. In the comparison with child group, the normal adult group showed smaller mandibular angle and mandibular plane angle, but not the other two groups. And the complete cleft group and the class III group showed the similar change. The normal and class III group showed increased XiCd/XiPog, but not the complete cleft group(p<0.01).

• Imaging Science in Dentistry
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• v.33 no.2
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• pp.85-90
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• 2003

Purpose : To investigate the differences between the position of the mandibular condyles in temporomandibular joints of patients presenting with normal occlusion and skeletal class III malocclusion. Materials and Methods: Forty-two subjects with normal occlusion and thirty-seven subjects exhibiting skeletal class III malocclusion prior to orthodontic treatment were included in the study. Transcranial radiographs of each subject were taken at centric occlusion and 1 inch mouth opening. The positional relationship between the mandibular condyles with articular fossae and articular eminences at two positional states were evaluated and analyzed statistically. Results: The mandibular condyles of the skeletal class III malocclusion group were found to be located more anteriorly from the center of the articular fossae compared to the normal occlusion group in centric occlusion. The mandibular condyles of the skeletal Class III malocclusion group were located more superiorly from the middle of articular height than those of the normal occlusion group in centric occlusion. However, these differences were not statistically significant. At 1 inch mouth opening, the mandibular condyles of the skeletal class III malocclusion group were placed more posteriorly from the articular eminences than those of the normal occlusion group. The mean angle of the articular eminence posterior slope were 56.51 ° ± 6.29° in the normal occlusion group and 60.37° ± 6.26° in the skeletal Class III malocclusion group. Conclusions: The mandibular condyles of the skeletal Class III malocclusion group were placed more anteriorly at centric occlusion and more posteriorly at 1 inch mouth opening when compared with those of the normal occlusion group.

• Journal of the korean academy of Pediatric Dentistry
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• v.28 no.3
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• pp.412-420
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• 2001

In the growing children with normal occlusion and class III malocclusion who need the early treatment to be helped to diagnose and to set up treatment plan by calculating the mean values of the lateral cephalometric measurements, cephalometric measurements by McNamara alalysis were achieved and compared on both the 84 elementary school children with normal occlusion and 83 class III malocclusion children at the age of 7 to 9 in Kwangju city and the results were as follows: 1. On the boys group, between normal occlusion and class III malocclusion, Effective maxillary length, Maxillomandibular differential, Facial axis, Nasion perpendicualr to pogonion, Point A perp to Mx 1, and A-Pog line to Mn 1 showed significant differences(p<0.05). 2. On the girls group, between normal occlusion and class III malocclusion significant differences were shown in Effective Maxillary length, Maxillomandibular differential, Mandibular plan angle, Nasion perpendicualr to Point A, Point A perp to Mx 1, A-Pog line to Mn 1(p<0.01). 3. There were no significant differences between normal occlusion and class III malocclusion of boys group but significant differences between them of girls group in Effective mandibular length(P<0.01). On the boys and girls group, Effective maxilla length of class III malocclusion was shorter than that of normal occlusion. 4. There were no significant differences between normal occlusion and class III malocclusion both in boys and girls at Anterior lower facial height. 5. There were significant differences between boys and girls both in class III malocclusion and normal occlusion at Anterior lower facial height and Mandibular plane angle(p<0.01).

• The korean journal of orthodontics
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• v.26 no.1 s.54
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• pp.65-82
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• 1996

This study was carried out to study the changing patterns in muscle activities in Angle's II and Class III malocclusion patients following activator therapy, To study the activities of anterior temporal(T.A.), masseter(M.M.), posterior temporal(T.P.), and anterior belly of digastric(D.A.) muscles, surface electrodes were placed on 15 Angle's Class II and 17 Angle's Class III malocclusion patients and following conclusions were obtained after electromyographic recordings were taken at prior to the activator therapy and at some time between 6 -12 month after the start of activator therapy. 1. Class II and Class III malocclusion groups, when compared to normal occlusiongroup, showed no significant differences during resting and swallowing. But significant differences were observed in masseter and posterior temporal muscles during clenching. 2. Most of the muscles studied showed a certain pattern, that is those groups whose pre-treatment E.M.G. were lower than the normal value showed significant increase after activator therapy, whereas those groups whose pre-treatment E.M.G. were higher than the normal value showed significant decrease after activator therapy. This pattern was observed in all of the muscle groups studied except T.A.(swallowing), T.P.(clenching) and D.A.(swallowing, clenching) in Angle's Class III malocclusion group and in Angle's Class II malocclusion group, above tendency were observed only in T.A.(swallowing), M.M.(resting, swallowing) and T.P.(clenching). This pattern was less obvious during clenching. 3. When E.M.G. activity after activator therapy between Angle's Class II and Class III malocclusion group was compared, Class III malocclusion group showed more increase during resting, and Class II malocclusion group showed more increase during swallowing and clenching excepting M.M. and D.A. respectively.

• The korean journal of orthodontics
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• v.40 no.5
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• pp.349-357
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• 2010

Objective: The purpose of this study was to evaluate the dentoskeletal and soft tissue profile changes after extraction of two lower first or second premolars in "borderline" adult skeletal Class III cases. Methods: Twenty-eight patients with "borderline" skeletal Class III malocclusion were studied. All of them were treated by extraction of two lower first or second premolars. Lateral cephalometric radiographs taken at the start and end of treatment were analysed. Twenty-five cephalometric variables were calculated and paired $t$-tests were performed. Results: After treatment, no significant changes were noted in the skeletal parameters ($p{\geq}0.05$). Regarding the dental parameters, the L1-MP angle decreased by $8.1^{\circ}$, the U1-L1 angle increased by $7.7^{\circ}$ ($p$ < 0.01), the overjet distance increased by 5.7 mm ($p$ < 0.01), the L1-NB angle decreased by $7.3^{\circ}$ and the L1-NB distance decreased by 4.8 mm ($p$ < 0.01). The soft tissue parameters of Li-E, Li-H and Li-RL2 distance decreased by 3.2 mm, 3.4 mm and 4.1 mm respectively ($p$ < 0.01). Conclusions: Orthodontic camouflage treatment by extraction of two lower first or second premolars provides a viable treatment alternative for "borderline" skeletal Class III cases to achieve a good occlusal relationship.

• The korean journal of orthodontics
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• v.22 no.3 s.38
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• pp.735-753
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• 1992

The purpose of this study was to analyze the positions of upper and lower incisors according to facioskeletal patterns. The lateral cephalometric radiographs of sixty persons with normal occlusion, forty persons with Class II Division 1 malocclusion, and forty persons with Class III malocclusion all above the age of 18, were analyzed. The following results were obtained. 1. C I angle, the measurement related to masticatory system, were $89.20{\pm}4.34^{\circ}$ in normal occlusion group, $81.68{\pm}士5.95^{\circ}$ in Class II Division 1 malocclusion group and $101.96{\pm}6.31^{\circ}$ in Class III malocclusion group. 2. In comparison with the positions of upper and lower incisors according to facioskeletal patterns, Class II Division 1 malocclusion group showed that upper incisors were different significantly in all measurements and inclined labially (P < 0.05). Lower incisors were different significantly in all measurements except LI-APog, LI-APog (mm), LI-AB, LI-AB (mm) and inclined labially (P < 0.05), Class III malocclusion group showed that upper incisors were different significantly in all measurements except UI-SN, UI-OP, and inclined labially (P < 0.05). Lower incisors were different significantly in all measurements and inclined lingually (P < 0.05). 3. In all facioakeletal patterns, LI-SN and LI-PH ware correlated moderately to facioskeletal measurements, and FMA was correlated moderately to measurements of lower incisor position. 4. Regardless of the facioskeletal patterns, the reference planes equally applicable were AB line in the measurements of upper incisor and APog line in the measurements of lower incisor.

• The korean journal of orthodontics
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• v.25 no.4
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• pp.425-432
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• 1995

The purposee of this study is to investigate the correlation between the horizontal and vertical discrepancy of facial bones and the horizontal and vertical position of glenoid fossa. For this study, the cephalograms were taken to the adults over 18 of age(96 men and 108women). The cephalograms were divided into three groups according to the ANB angle(below 0.5 degree, 0.5 to 4.0 degree and above 38 degree), and they were divided into three groups according to the SN-MP angle(below 30 degree, 30 to 38 degree and above 38 degree). The following conclusions were obtained : 1. In the horizontal discrepancy of facial bone(ANB), the horiontal position of glenoid fossa(X) was anterior position as the order of Class II, Class I, Cias III. 2. The horizontal position of glenoid fossa(X) showed the significant correlation with ANB and SNB, but not with SNA. 3. In the vertical discrepancy of facial bone(SN-MP), thee less anglee was the greater vertical position of glenoid fossa (X) and was followed by the medium and high angle in order. 4. The vertical position of glenoid fossa(Y) showed thhat the SN-FH was the most significant correlation, and it was followed as the order of SN-FH, SN-MP and SN-OP angle. 5. There was the samllest length of anterior cranial base in the Class III malocclusion.

• The korean journal of orthodontics
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• v.52 no.3
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• pp.210-219
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• 2022

Objective: The purpose of this study was to examine the effectiveness and mechanism of clear aligner therapy for the correction of anterior open bite in adult nonextraction cases. Methods: Sixty-nine adult patients with anterior open bite were enrolled and classified into Angle's Class I, II, and III groups. Fifty patients presented with skeletal open bite (mandibular plane angle [MPA] ≥ 38°), whereas 19 presented with dental open bite. Fifteen cephalometric landmarks were identified before (T1) and after (T2) treatment. The magnitudes of planned and actual movements of the incisors and molars were calculated. Results: Positive overbite was achieved in 94% patients, with a mean final overbite of 1.1 ± 0.8 mm. The mean change in overbite was 3.3 ± 1.4 mm. With clear aligners alone, 0.36 ± 0.58 mm of maxillary molar intrusion was achieved. Compared with the Class I group, the Class II group showed greater maxillary molar intrusion and MPA reduction. The Class III group showed greater mandibular incisor extrusion with no significant vertical skeletal changes. Conclusions: Clear aligners can be effective in controlling the vertical dimension and correcting mild to moderate anterior open bite in adult nonextraction cases. The treatment mechanism for Class III patients significantly differed from that for Class I and Class II patients. Maxillary incisor extrusion in patients with dental open bite and MPA reduction with mandibular incisor extrusion in patients with skeletal open bite are the most significant contributing factors for open bite closure.

• The korean journal of orthodontics
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• v.24 no.4 s.47
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• pp.861-869
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• 1994

The purpose of this study was to investigate the relationship of nose profile with respect to skeletodental pattern, by measured and analyzed statistically the lateral cephalograms of 95 females (13 to 30 years old). Tge results were summerized as follows ; 1. The antero-posterior factors of the nose - nasofrontal angle, nasofacial angle, and dorsal length / ala length ratio were different among the malocclusion groups 2. There were no significant correlation between the the vertical nose factors and the skeletal factors 3. The Class I groups had a straight nose profile , the Class II groups had a convex profile ; the Class III groups had a concave profile.

• The korean journal of orthodontics
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• v.32 no.2 s.91
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• pp.117-127
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• 2002

The purpose of this study was to compare the arch width of the hyperdivergent group with that of the neutral group in Class III malocclusion based on the vertical patterns and to compare the arch width of Class III neutral group With that of normal occlusion group based on sagittal patterns. The subjects consisted of 118 pairs of studty casts, divided into three groups , 37 Class III hyperdivergent group(18 males and 19 females, SN-Mn plane angle>39.5$^{\circ}$), 40 Class III neutral group(20 males and 20 females, SN-Mn plane angle : 32 ${\pm}$ 2.5$^{\circ}$) and 41 Class I normal occlusion group(20 males and 21 females). The intercanine, interpremolar, and intermolar width of the maxillary and mandibular study casts were measured, then the ratios of dental width to basal width and mandibular width to maxillary width were obtained. Basal arch width and dental arch width were measured to obtain the pure basal arch relation in transverse plane as ruled out the transverse dental compensation. The results were as follows 1. There were no significant differences in any ratios between Class III hyperdivergent group and Class III neutral group as different vertical pattern. 2. As the ratios of dental arch width to basal arch width between normal occlusion group and Class III neutral group were compared, the maxillary teeth flared buccally to the basal bone, and the mandibular teeth tilted lingually to the basal bone in Class III neutral group. 3. The ratios of mandibular arch width to maxillary arch width in basal arch level were significantly different in all regions. Maxillary basal arch width of Class III neutral group was narrower than that of normal occlusion group. 4. The ratios of mandibular arch width to maxillary arch width in teeth level were not significantly different between normal occlusion group and Class III neutral group. In spite of discrepancies of maxillary and mandibular basal arch width, the dental arch width of Class III malocclusion group compensated very well. At the presurgical orthodontic treatment in clinic, it would not be desirable to decompensate for compensated dental arch width too much, for obtaining an appropriate arch compatibility and good results for orthognathic surgery.