• The korean journal of orthodontics
• /
• v.49 no.3
• /
• pp.170-180
• /
• 2019

Objective: The purpose of this study was to investigate the relationship between the facial skeletal patterns and the shape of the mandibular symphysis in adults with malocclusion by using a structural equation model (SEM). Methods: Ninety adults who had malocclusion and had records of facial skeletal measurements performed using cone-beam computed tomography were selected for this study. The skeletal measurements were classified into three groups (vertical, anteroposterior, and transverse). Cross-sectional images of the mandibular symphysis were analyzed using generalized Procrustes and principal component (PC) analyses. A SEM was constructed after the factors were extracted via factor analysis. Results: Two factors were extracted from the transverse, vertical, and anteroposterior skeletal measurements. Latent variables were extracted for each factor. PC1, PC2, and PC3 were selected to analyze the variations of the mandibular symphyseal shape. The SEM was constructed using the skeletal variables, PCs, and latent variables. The SEM showed that the vertical latent variable exerted the most influence on the mandibular symphyseal shape. Conclusions: The relationship between the skeletal pattern and the mandibular symphysis was analyzed using a SEM, which showed that the vertical facial skeletal pattern had the highest effect on the shape of the mandibular symphysis.

• The korean journal of orthodontics
• /
• v.17 no.1
• /
• pp.135-148
• /
• 1987

To investigate the relationship between craniofacial growth and bone maturity of the hand wrist in normal occlusion, the author took cephalogram and handwrist radiogram of 391 students (male 192, female 199) and assessed the measurements of cephalogram according to skeletal maturity stages of the hand and wrist. In this study, four skeketal stages and 36 linear, angular measurements of the cephalometrics were selected. In hand-wrist X-ray the bones used to determine skeletal maturity were the middle phalanges of the third finger, and distal epiphysis of the radius. In cephalogram, the landmark used to measure the angle and length were N, S, Po., Ar., Go., Me., Gn., Pog., Point B, Point A, ANS, PNS, Or., U1, L1, U6, L6 etc.. The results were as follows, 1. The table of mean, standard deviation, p-value from measurements were made in each group and both sex. 2. The increased measurements according to skeletal maturity were anterior cranial bese length, posterior cranial base length, ramus height, anterior facial height, posterior facial height, L1 to mandibular plane (mm), facial plane angle. In contrast to, decreased measurements were genial angle, facial cnvexity and facial plane angle. 3. Denture pattern measurements (IMPA, FMIA, occlusal plane to Go-Gn, interincisal angle, U1 to SN plane, U1 to SN plane, U1 to facial plane, L1 to facial plane etc.) .had nothing to do with skeletal maturity. 4. Skeletal maturity had close relationship with craniofacial growth, but had little to do with tooth development.

• The korean journal of orthodontics
• /
• v.49 no.4
• /
• pp.254-264
• /
• 2019

Objective: To evaluate the short-term changes in masticatory muscle activity and mandibular movement patterns after orthognathic surgery in skeletal Class III patients with facial asymmetry. Methods: Twenty-seven skeletal Class III adult patients were divided into two groups based on the degree of facial asymmetry: the experimental group (n = 17 [11 male and 6 female]; menton deviation ${\geq}4mm$) and control group (n = 10 [4 male and 6 female]; menton deviation < 1.6 mm). Cephalography, electromyography (EMG) for the anterior temporalis (TA) and masseter muscles (MM), and mandibular movement (range of motion [ROM] and average chewing pattern [ACP]) were evaluated before (T0) and 7 to 8 months (T1) after the surgery. Results: There were no significant postoperative changes in the EMG potentials of the TA and MM in both groups, except in the anterior cotton roll biting test, in which the masticatory muscle activity had changed into an MM-dominant pattern postoperatively in both groups. In the experimental group, the amount of maximum opening, protrusion, and lateral excursion to the non-deviated side were significantly decreased. The turning point tended to be shorter and significantly moved medially during chewing in the non-deviated side in the experimental group. Conclusions: In skeletal Class III patients with facial asymmetry, the EMG activity characteristics recovered to presurgical levels within 7 to 8 months after the surgery. Correction of the asymmetry caused limitation in jaw movement in terms of both ROM and ACP on the non-deviated side.

• The korean journal of orthodontics
• /
• v.48 no.6
• /
• pp.357-366
• /
• 2018

Objective: The purpose of this study was to analyze the transverse dental compensation in reference to the maxillary and mandibular basal bones using cone-beam computed tomography (CBCT) and evaluate the correlations between transverse dental compensation and skeletal asymmetry variables in patients with skeletal Class III malocclusion and facial asymmetry. Methods: Thirty patients with skeletal Class I (control group; 15 men, 15 women) and 30 patients with skeletal Class III with menton deviation (asymmetry group; 16 men, 14 women) were included. Skeletal and dental measurements were acquired from reconstructed CBCT images using OnDemand3D 1.0 software. All measurements were compared between groups and between the deviated and nondeviated sides of the asymmetry group. Correlation coefficients for the association between skeletal and dental measurements were calculated. Results: Differences in the ramus inclination (p < 0.001), maxillary canine and first molar inclinations (p < 0.001), and distances from the canine and first molar cusp tips to the midmaxillary or midmandibular planes (p < 0.01) between the right and left sides were significantly greater in the asymmetry group than in the control group. In the asymmetry group, the ramus inclination difference (p < 0.05) and mandibular canting (p < 0.05) were correlated with the amount of menton deviation. In addition, dental measurements were positively correlated with the amount of menton deviation (p < 0.05). Conclusions: Transverse dental compensation was correlated with the maxillary and mandibular asymmetry patterns. These results would be helpful in understanding the pattern of transverse dental compensation and planning surgical procedure for patients with skeletal Class III malocclusion and facial asymmetry.

• The korean journal of orthodontics
• /
• v.24 no.4 s.47
• /
• pp.851-860
• /
• 1994

Before 1970, mandibular overgrowth was known as main cause of skeletal Class III malocclusion in growing children ; however, recent study reports that many skeletal Class III malocclusion patients also show maxillary deficiency. Since 1972, when Delaire re-accommodated Protraction Head Gear (P.H.G.), many researchers have reported that skeletal Class III discrepancies could be corrected through use of P.H.G., which induces anterior movement of maxilla and change in mandibular growth pattern into infero-posterior direction ; nevertheless, it is very difficult to predict resultant changes of orofacial region. The purpose of this study was to find out what treatment effect P.H.G. has on different study samples. Author divided 51 skeletal Class III malocclusion patients with maxillary deficiency who were treated with P.H.G. into different study groups depending on sex, treatment beginning age, intraoral appliance, and facial growth pattern. By doing so, following results were obtained. 1. Treatment beginning age and Sex Four age groups (5.8 to 8 year-old, 8 to 10 year-old, 10 to 12 year-old, 12 to 14 year-old) were compared, and no significant difference was observed. (p<0.05) There was no significant difference between the sex groups, either. (p<0.05). 2. Intraoral appliance Treatment effects of study groups that used R.P.E.(mean age of 10.2) and Labio-Lingual appliance(mean age of 8.9) were compared. There was no significant difference depending on the type of intraoral appliance that was used. (p<0.05) 3. Facial growth pattern 1) Amounts of SNB and ANB corrections were smaller in clockwise growth pattern group than those in normal or counterclockwise growth pattern group. (p<0.05) 2) Amounts of increase in Wits appraisal and mandibular plane angle were greater in counterclockwise growth pattern group than those in normal or clockwise growth pattern group. (p<0.05) 3)Amounts of increase in articular angle were greater in counter lockwise growth pattern group than those in clockwise growth pattern group. (p<0.05)

• Journal of Korean Academy of Oral and Maxillofacial Radiology
• /
• v.3 no.1
• /
• pp.29-34
• /
• 1973

The study was made on the facial profile of the normal Korean adults using the roentgenographic cephalograms. The subjects ccnsisted of 50 males and 50 females with the normal occlusion. The measurements were made of the facial angles in skeletal pattern and depth, height and the length in the soft tissue profile. The mean and standard deviations from the subjects were calculated and compared with the samples of male and female. The authors have drawn the conclusions as follows: 1. Compared with the angulation in skeletal patterns, there were no differences between both sexes. 2. Individual variations of the lower face were larger than the upper face in most measuring points. 3. Generally, facial heights were lesser than facial depth in sexual differences. 4. Most dimensions of the facial depth, height and length of the male were larger than those of female.

• The Journal of the Korean dental association
• /
• v.57 no.6
• /
• pp.344-351
• /
• 2019

Skeletal Class III malocclusion is a relatively common form of malocclusion in Korea. In borderline cases where only mild skeletal discrepancy exists and if worsening of the facial profile is expected as a result of premolar extraction, mandibular full arch distalization with miniscrews is the treatment of choice. The purpose of this study was to investigate the pattern of tooth movement and evaluate the stability of mandibular full arch distalization and to identify correlation between stability and factors such as initial skeletal pattern, dental changes during treatment and alveolar bone in symphysis region using lateral cephalograms.

• The korean journal of orthodontics
• /
• v.29 no.5 s.76
• /
• pp.575-587
• /
• 1999

This study was designed to evaluate the correlations between tongue with skeletal pattern and intermaxillary space in Class II malocclusion adult patients. Craniofacial skeletal pattern was analyzed on the lateral cephalometric radiograph and the subjects were devided two groups by facial ratio, the 30 subjects of hyperdivergent group and the 30 subjects of hypodivergent group. The size and posture of tongue and intermaxillary space were measured on the lateral cephalometric radiograph. These data were statistically analyzed to examine significant differences between both groups and compared the correlation between tongue with skeletal measurements and intermaxillary space in each group. The results of this study were as follows. 1. In comparison of the tongue and intermaxillary space, the measurement of TS/IS showed significantly larger in hyperdivergent group and PIH and IS showed significantly larger in hypodivergent group. There were no statistically significant differences in the measurements of the height and posture of tongue. 2. In correlation between tongue with craniofacial skeletal measurements, the length and height of tongue showed the highest correlation with AFH(anterior facial height) in both groups(p<0.01). And that measurements showed high correlation with PFH(posterior facial height) in hypodivergent group. 3. In both groups, most measurements of tongue showed high correlation with intermaxillary space and the height and space of tongue showed high correlation with AIH and PIH(p<0.01).

• Journal of Dental Rehabilitation and Applied Science
• /
• v.16 no.2
• /
• pp.93-104
• /
• 2000

Orthodontic treatment in conjunction with second-molar extraction has been a controversial issue among orthodontists over many decades. The aim of this study was to investigate the treatment effects of upper second molar extraction cases. The sample included 19 upper second molar extraction orthodontic cases(ten Angle's Class I's and nine Class II's, average age=13Y 6M) cared at Kyung-Hee University Department of Orthodontics. Lateral cephalometric radiographs were taken before and immediately after treatment. Seventy-nine points were digitized on each cephalogram and 38 cephalometric parameters were computed comprising 22 angular measurements, 13 linear measurements, and 3 facial proportions. The data obtained from each malocclusion group were analyzed by paired t-test. The statistical results disclosed that there was no significant change in skeletal pattern after treatment except for that accountable by growth while there was statistically significant change in dentoalveolar and soft tissue patterns. There were no significant changes in Bjork sum, posterior facial height /anterior facial height and lower anterior facial height /anterior facial height. No significant changes in anteroposterior position of maxilla and palatal plane were manifested. Although facial axis and lower facial height was slightly increased and the mandible was rotated backward and downward, there was no remarkable change in the mandibular plane. There were statistically significant changes in distal movement of upper first molar, molar key correction and overjet reduction while there was no change in the occlusal plane. The upper lip was slightly retracted simultaneously with slight increase in nasolabial angle. These results signify that distalization of upper dentition with the second molar extraction does change occlusal relationship without gross modifications in the craniofacial skeletal configurationson. Henceforth the second molar extracted would be recommended to treat severe anterior crowding and protrusion with minor skeletal discrepancy.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• v.34 no.6
• /
• pp.622-627
• /
• 2008

In orthognathic surgery, precise analysis and diagnosis are essential for successful results. In facial asymmetric patient, traditional 2D image analysis has been used by lateral and P-A Cephalometric view, Skull PA, Panorama, Submentovertex view etc. But clinicians sometimes misdiagnose because they cannot find exact landmark due to superimposition, moreover image can be magnified and distorted by projection technique or patient's skull position, when using these analysis and method. For overcome these defects, analysis by using of 3D CT has been introduced. In this way we can analysis precisely by getting the exact image free of artifact and finding exact landmark with no interruption of superimposition. So we want to review of relationship between various skeletal landmarks of mandible or cranial base and facial asymmetry by predictable analysis using 3D CT. We select the cases of the patients who visited our department for correction of facial asymmetry during 2003-2007 and who were taken image of 3D CT for diagnosis. 3D CT images were reconstructed to 3D image by using V-Work program (Cybermed Inc., Seoul, Korea). And we analysis the relationship between facial asymmetry and various affecting factor of skeletal pattern. The mandibular ramus hight difference between right and left was most affecting factor that express facial asymmetry. And in this research, there was no relationship between cranial base and facial asymmetry. The angulation between facial midline and mandibular ramus divergency has significant relationship with facial asymmetry