• The korean journal of orthodontics
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• v.25 no.4
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• pp.375-401
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• 1995

Cause of skeletal Class III malocclusion in growing patients can be classified into maxillary deficiency, mandibular overgrowth, and combination of the two. Use of Protraction Head Gear(P.H.G.) has been recommended for treatment of growing Class III malocclusion patients, for it results in forward & downward movement of maxilla and backward & downward rotation of mandible. Numerous animal experiments were performed and clinical study data have been reported ; nevertheless, studies on soft tissue profile change and comparison of treatment effects among the patients who had undergone treatment are considered to be somewhat insufficient. The author selected 93 patients, who had been diagnosed as skeletal Class III malocclusion with maxillary deficiency and then treated with P.H.G. ; the sample group was divided according to sex, treatment beginning age, palatal suture opening(intraoral appliance), and facial growth pattern. For each group, changing patterns of hard and soft tissue profile observed, and comparision with 20 normal group(Angle's Class I) patients of statistical significance in amount of growth and treatment of hard and soft tissue was done. The following results were obtained. 1. Skeletal, dental, and soft tissue measurements indicated that more growth changes was induced in the sample group that used P.H.G. compared to the growth amount of normal group. 2. No statistical significance was observed in the amounts of maxillary forward movement and mandibular backward & downward rotation depending on treatment beginning age in both sex group. 3. R.P.E. showed more significant maxillary forward movement and less protrusion of upper incisor than La-Li. 4. There was no statistical significance in the amount of maxillary forward movement depending on facial growth pattern. On the other hand, measurements indicating mandibular downward & backward rotation indicated greater change in counterclockwise growth pattern group than the clockwise. 5. Changes in upper and lower lip thicknesses showed a close relationship with positional changes in underlying bone tissue and upper and lower teeth, and upper lip height and nasolabial angle increased and mentolabial angle decreased.

• The korean journal of orthodontics
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• v.37 no.1 s.120
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• pp.73-84
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• 2007

The maxillary protraction headgear has been widely used in the treatment of skeletal Class III children with maxillary deficiency. A variety of treatment objectives which allow dentoalveolar movements may be established, but when only maxillary protraction without dentoalveolar movement is needed, one of the limitations in maxillary protraction with conventional tooth-borne anchorage is the loss of dental anchorage. This is because a bone remodeling occurs not only at circummaxillary sutures but also within the periodontal tissues. During protraction treatment in the mixed dentition phase, in older children or for the patient with multiple congenitally missing teeth, it is not uncommon to observe undesirable mesial movement of maxillary teeth. Such a side effect can be eliminated or minimized using absolute anchorage such as skeletal anchorage. The purpose of this case report is to introduce a new technique of the maxillary protraction headgear treatment using surgical miniplates.

• Journal of the korean academy of Pediatric Dentistry
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• v.49 no.2
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• pp.234-240
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• 2022

Floating-Harbor syndrome (FHS) is a rare genetic disorder. This report introduced in a patient with FHS. Distinctive facial characteristics, severe skeletal class 3 malocclusion with underdeveloped maxilla and protruded mandible, congenital missing teeth, microdontia and ectopic positions of maxillary teeth were presented in the patient. In his twin sister, mild skeletal class 3 malocclusion with protruded mandible was observed but congenital missing teeth and microdontia were not observed. High-arched palate, narrow V-shaped maxillary arch compared to wide and ovoid mandibular arch and inverse relationship between the maxillary and mandibular intermolar width resulted in posterior crossbite were confirmed by model analysis of the patient. These were not observed in the twins. Behaviorally, poor cooperation during dental treatment because of mental retardation was observed in the patient.

• The korean journal of orthodontics
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• v.28 no.4 s.69
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• pp.517-531
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• 1998

The purpose of this study was to investigate the changes in the craniofacial skeleton subsequent to chincap therapy in the juvenile skeletal Class III malocclusion with more appropriate control samples. The experimental group consisted of 29 Korean children(14 males, 15 females) who had skeletal Class III malocclusion with prognathic mandible and were undergone chincap thorny from the beginning of treatment. The control group was composed of 21 Korean children(10 males, 11 females) who had no orthodontic treatment, but with similar skeletal discrepancies to experimental group. Lateral cephalometric radiographs at the age of 7, and 2 years later were analyized and compared with student's t-test(p<0.05). The results of this study were as follows; 1. The control group without chincap therapy had not shown any improvement of the skeletal discrepancies, but had grown to be much severe. This means that the untreated Class III patient with prognathic mandible would not be corrected by growth. For the experimental group with chincap therapy, the anterior-posterior skeletal discrepancies and mandibular prognathism were both improved. 2. Neither significant restraint nor acceleration of growth was found in the cranial base and maxilla by chincap treatment. 3. The inhibition of mandibular growth could not be accepted, but the changes of the direction of growth and morphological changes were found. 4. Vertical growth tendency was increased with chincap therapy. 5. When Putting together the results of the analyses , it seems to be the rotation and displacement of the mandible that the major treatment effects of chincap we. The changes of the direction of growth and the morphological changes also seems to contibute to the treatment effect partly. In summary, the chincap doesn't restrain the mandibular growth. But, it is considered as a useful treatment modality for correction of skeletal discrepancies and reduction of mandibular prognathism in growing Class III patients with madibular prognathism.

• The korean journal of orthodontics
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• v.28 no.5 s.70
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• pp.763-774
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• 1998

The purpose of this study was to evaluate the morphology of mandibular symphysis and location of lower incisor under the influence of the craniofacial skeleton in skeletal Class III malocclusion. The sample consisted of 132 adults who have severe Class III malocclusion(prognathism group, 33 males and 33 females), and who have normal occlusion(normal group, 33 males and 33 females). They had not received any orthodontic treatment or orthognathic surgery. The lateral cephalograms were evaluated. The results were as follows : 1. Prognathism group were larger than normal group in comparison of facial skeleton (p<0.05) with the exception of ${\angle}FH-Pal$, ${\angle}SNA$. 2. In the morphology of symphysis, measurements of anteroposterior width(LaABBW, LiABBW, SW) of prognathism group were significantly less than that of normal group(p<0.001). 3. In the correlative analysis between the craniofacial skeleton and symphysis measurements of prognathism group, vertical measurements in relation with cranial base and mandibular plane showed reverse correlationship with anteroposterior width of symphysis(LiACBW, LaACBW, LiABBW, SW)(p<0.05). But, there was not distinct difference between horizontal skeletal measurements and symphysis measurements(p>0.05). 4. The probability by regression test between vertical measurements(${\angle}SN-Mn,\;{\angle}FMA,\;{\angle}Pal-Mn,\;{\angle}LFH$) and symphysis measurements(LiACBW, LiABBW, SW, ${\angle}LISA$) were very high(p<0.001).

• The korean journal of orthodontics
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• v.27 no.6 s.65
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• pp.871-880
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• 1997

Multiple features of occlusion have been combined by epidemiologists in attempts to objectively to determine malocclusion severity and treatment priority. Jenny et al were developed DAI(Dental Aesthetic Index), which is an orthodontic index based on socially defined aesthetic standards. This study aimed to evaluate association between 10 occlusal components of DAI and individual measures of skeletal morphology by use of univariate and multivariate analysis. In addition the relationship between a Dental Aesthetic Index score and skeletal morphology was evaluated. The data for this study were obtained from cephalometric radiographs and dental casts of 182 Korean patients(79 men, 103 women) with permanent dentition who had been accepted for the orthodontic treatment at Department of Orthodontics, Chonbuk National University. The results are as follows: 1. Several occlusal components of DAI(missing, crowding and spacing in the incisal segment, diastema, largest anterior irregularity on upper and lower arch) were not associated with individual measures of craniofacial morphology. 2. Sagittal occlusal components of DAI were associated with anteroposterior skeletal measures. 3. The relation between vertical occlusal components of DAI and vertical skeletal measures was low magnitude. 4. A Dental Aesthetic Index, which is based on several aspects of occlusion, did not identify craniofacial morphology. We can conclude that combination of certain occlusal components of the DAI may be related with specific skeletal morphology; but, this concept could not be accepted generally.

• The korean journal of orthodontics
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• v.26 no.3
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• pp.247-254
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• 1996

This study was performed to evaluate the hyoid bone position and airway in skeletal class III malocclusion and to prove the correlation between airway, hyoid bone position and mandibular position. The sample, considered of 47 class III malocclusion patients for experimmtal group and 52 class I malocclusion students for control group. Twenty three linear and angular measurements about hyoid bone position, airway size, mandibular position were taken from the lateral cephalograms. The differences between skeletal class III malocclusion group and normal occlusion group were compared and the correlation were evaluated statistically. The results obtained were as follows, 1. There were significant difference in S-APH, A-APH, N-APH, LAH-PBR, AA-PNS, PNS-ad between class I and class III malocclusion groups. 2. The hyoid bone was more anteriorly positioned in class III malocclusion group than class I malocclusion group and skeletal airway size in class III malocclusion group was smaller than class I malocclusion group. 3. There were significant difference in several measurements especially vertical and angular measurements of hyoid bone position and airway size between male and female. Usually the measurements in male were larger than female. 4. There were no significant correlation between hyoid bone position and airway size also airway size, and didn't showe significant correlation with mandibular position, 5. S-APH showed negative correlation with Wits appraisal and A-APH, N-APH showed positive correlation with Wits appraisal. On the contrary vertical measurements of hyoid bone position showed positive correlation with lower facial height.

• The korean journal of orthodontics
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• v.37 no.3 s.122
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• pp.192-203
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• 2007

Objective: The aim of this study was assessment of the relationship between airway space and facial morphology in Class III children with nasal obstruction. Methods: For this study, 100 Class III children (50 boys and 50 girls) were chosen. All subjects were refered to ENT, due to nasal obstruction. Airway space measurements and facial morphology measurements were measured on lateral cephalometric radiograph. Pearson correlation analysis was used to assess the relationship between airway space and facial morphology Results: Ramal height, SNA, SNB, PFH, FHR and facial plane angle were positively related to upper PAS, and sum of saddle angle, articular angle, and genial angle, SN-GoGn, Y-axis to SN and FMA negatively related to upper PAS. Genial angle, FMA were positively related to lower PAS, and articular angle, facial depth, PFH and FHR negatively related to lower PAS. PCBL, ramal height, Mn. body length, Mn. body length to ACBL, facial depth, facial length, PFH and AFH were positively related to tonsil size. Sum of saddle angle, articular angle, genial angle, facial length, AFH, FMA and LFH were positively related to tongue gap, and IMPA and overbite was negatively related to tongue gap. Upper PAS, related to size of adenoid tissue, was mainly related to posterior facial dimension following a vertical growth pattern of face and mandibular rotation. Lower PAS and tonsil size, related to anterior-posterior tongue base position, were significantly related to each other. Lower PAS was related to growth pattern of mandible, and tonsil size was related to size of mandible and horizontal growth pattern of face. Tongue gap was related to anterior facial dimension following a vertical growth pattern of face. Conclusion: Significant relationship exists between airway space and facial morphology.

• The korean journal of orthodontics
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• v.30 no.3 s.80
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• pp.307-315
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• 2000

This study was performed to evaluate the reproducibility of natural head position according to skeletal malocclusion types and sex using cephalometric radiographs for establishing orthodontic diagnosis and treatment planning. The sample consisted of 90 young adults (male 45, female 45) who had the skeletal malocclusion. Cephalometric radiographs were taken in natural head position, and statistical analysis was performed and method error of 6 postural variables were estimated to evaluate the reproducibility of the natural head position. The following results were obtained : 1. In the reproducibility of the natural head position, postural variables had no statistical significance In male and female (P>0.05). 2. In the reproducibility of the natural head position, postural variables had no statistical significance in Class I, II, III, and total group (P>0.05). 3. The reproducibility of natural head position using method error was excellent in all groups.

• 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.