• Maxillofacial Plastic and Reconstructive Surgery
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• v.13 no.1
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• pp.37-43
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• 1991

Cephalometric prediction tracing is the preoperative double checking procedure which can predict bony and soft tissue change. Soft tissue profile prediction is routinely performed according to the known ratios of the soft to hard tissue movement which can vary considerably in each individual. Besides interindividual variation of the ratios of the soft to hard tissue change, actual results of the postoperative soft tissue profile can reflect other important modifying factors if it is compared with prediction tracing used. The purpose of this study is to compare soft tissue prediction tracing used with postoperative tracing and to find intervening modifying factor via serial tracing. Review of 30 prediction tracing showed that the most important factor contributing to prodiction tracing inaccuracy was the skeletal and dental relapse. And, some factors which may be responsible for prediction tracing inaccuracy were discussed.

• The korean journal of orthodontics
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• v.32 no.3 s.92
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• pp.155-163
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• 2002

This study was performed to assess the accuracy of computer-based treatment prediction for soft tissue profile using Quick Ceph Image $Pro^{TM}\;&\;Quick\;Ceph\;2000^{TM}$ in bimaxillary protrusion cases. The Ore- and post-treatment lateral cephalograms of 21 female adults treated by low first premolar extraction were imaged and 9 landmarks and 27 specific soft tissue mesurements were digitized for comparing actual treatment results with computer simulations. The results of this study showed that Quick Ceph Image $Pro^{TM}\;&\;Quick\;Ceph\;2000^{TM}$ tends to overestimeate horizontal changes and underestimate vertical changes. In the computer simulation, upper lip showed rolling tendency. The upper lip measurements were disposed to be regular direction hut lower lip measurements were varied case by case even if it was statistically insignificant.

• The korean journal of orthodontics
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• v.29 no.3 s.74
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• pp.285-301
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• 1999

There is a need for more accurate prediction in surgical orthodontic treatment. Video imaging is an important technology in planning orthognathic surgery and educating patients about the esthetic results after treatment. Preoperative and postoperative lateral cephalogram of 30 patients who had one piece Le Fort I osteotomy advancement and mandibular set back by bilateral intraoral vertical ramal osteotomy with or without genioplasty were used in this study. The computer generated soft tissue line drawing prediction were compared with the actual postoperative cephalograms .The results are as follows. 1. 14 variables showed Statistically significant differences from 24 variables between computer predicted profile and post operative profile 2. Most of the differences were found in the maxilla-related soft tissue landmarks. 3. The predicted results were more accurate in the groups who had small amount of mandibular set back. 4. The predicted results were more accurate in the groups who had no genioplasty. Most of these differences were within 2mm ranges. Therefore profile change prediction by video imaging could be considered clinically acceptable.

• The korean journal of orthodontics
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• v.29 no.4 s.75
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• pp.399-409
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• 1999

The purpose of this study was to evaluate the change of soft tissue profile on lower face following retraction of incisors through orthodontic treatment. 31 Korean women with bialveolar protrusion who were treated with 4 first bicuspid extraction were selected. All of samples were treated from above 17 years of age. Lateral cephalometric head films taken before and after treatment were analyzed statistically. The results were obtained as follows. $\cdot$The ratio of upper incisor retraction to upper lip retraction and lower incisor retraction to lower lip retraction were 1.54:1 (r=0.746) and 0.92:1 (r=0.584) respectively $\cdot$It appeared during orthodontic treatment that UIS-LS was increased considerably and the others in soft tissue thickness measurements were slightly decresed. $\cdot$Analysis of correlation showed that the change of the upper lip (LS) with the change of maxillary central incisor (UIS) and the change of lower lip with the change of B point were most strongly correlated. $\cdot$The multiple regression equations were obtained to predict soft tissue profile change of lower face according to retraction of incisors.

• The korean journal of orthodontics
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• v.35 no.3 s.110
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• pp.216-226
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• 2005

The purpose of this study was to test and compare the accuracy and reliability of soft tissue profile predictions generated from two computer software programs (Quick Ceph Image $Pro^{TM}$ (ver 3.0) and $V-Ceph^{TM}$(ver 3.5)) for mandibular set-back surgery. The presurgical and postsurgical lateral cephalograms of 40 patients (20 males and 20 females) were traced on the same acetate paper with the reference taken as the cranial base outline. The presurgical skeletal outlines were digitized onto each computer program and the mandible was moved to mimic the expected surgical procedure with reverence to the mandibular anterior border and lower incisor position of the actual postsurgical skeletal outline. The soft tissue profile was generated and the amount and direction of skeletal movement was calculated with each software. The predicted soft tissue profile was compared to the actual postsurgical soft tissue profile. There were differences between the actual and the predicted surgical soft tissue profile charges in the magnitude and direction, especially the upper lip. lower lip and the soft tissue chin (P<0.05). Quick Ceph had more horizontal measurement errors and thickness errors for the upper lip and lower lip, but V-Ceph had more vertical measurement errors of the lower lip (P<0.05). There was a positive correlation between the prediction errors and the amount of mandibular movements in the vertical position of Sn, the horizontal position of Ls and the upper lip thickness for V-Ceph, and there was a negative correlation in the horizontal position and the thickness of the lower lip for Quick Ceph (P<0.05). However all of the Prediction errors of both imaging softwares were ranged within 3mm, and this was considered to be allowable clinically.

• The korean journal of orthodontics
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• v.27 no.1
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• pp.65-78
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• 1997

This study was carried out in order to determine soft tissue response to incisor movement and mandibular repositioning and to determine feasibility of predicting vertical and horizontal changes in soft tissue with hard tissue movement. For this study, cephalometric records of 41 orthodontically treated adult females who had Angle's Class II division 1 malocclusion were selected and stepwise multiple regression analysis was employed. Following conclusions were obtained by analysing the changes of soft tissue and hard tissue before and after treatment. 1. Hard tissue measurements that showed significant changes before and after treatment were horizontal and angular changes of maxillary incisor, horizontal,vertical and angular changes of mandibular incisor, overjet, overbite, interincisal angle, mandibular repositioning, A,B, skeletal convexity and soft tissue measurements that showed significant changes were horizontal, thickness and angular changes of upper lip, horizontal and angular changes of lower lip, interlabial angle, nasolabial angle labiomental angle, Sri, Ss, Si and soft tissue convexity(P<0.05). 2. All Soft tissue measurements changed significantly before and after treatment had between one and four hard tissue independent variables at statistically significant level, indicating that all soft tissue changes were direct relationship with hard tissue changes 3. Ova jet, horizontal change of maxillary incisor, horizontal change of maxillary root apex and horizontal change of pogonion entered into prediction equations most frequentely indicating that they were more significant variables in prediction of vertical and horizontal changes in the soft tissue with treatment, but vertical changes of mandibular incisor not entered any prediction equations, indicating that it was not considered a good predictor for soft tissue changes with maxillary incisor retraction. 4. Horizontal and vertical changes in subnasale were found to have most independent variables, significant at the 0.05 level in prediction-equations(${\Delta}$Sn(H):Ur, Is(H), Pg(H), UIA,${\Delta}$Sn(V): Is(H), Pg(H), overjet, A), indicating that subnasale changes are influenced by complex hard tissue interaction. 5. Multiple correlation coefficient($R^2$) of the soft tissue prediction equations ranges from 0.2-0.6.

• The korean journal of orthodontics
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• v.36 no.1 s.114
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• pp.63-73
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• 2006

Numbers of postulations lie on the difference of integumental changes with two major surgical remedies of one jaw vs. two jaw surgery in skeletal Class III malocclusion. Accordingly it was the aim of the study to elucidate the skeletal profile changes with an accompanying disposition of soft tissues, consequently to yield the correlation and ratio of soft tissue changes with two types of surgical procedures, which in turn make it possible to predict the soft tissue outcomes by means of assembled regression equations. Cephalometric headfilms of fifty two adult skeletal Class III comprised of 26 maxillary advancement by Le Fort I osteotomy and mandibular setback by sagittal split ramus osteotomy simultaneously (double jaw surgery, group A), 26 mandibular setback alone (one jaw surgery, group B) were statistically analyzed. Group A manifested 72.4% soft tissue advancement to skeletal changes in the upper lip area, while group B appeared to have no statistically significant changes. The nasolabial angle showed more increment in group A than in group B, whereas the mentolabial angle illustrated more reduction in group B. The backward movement of soft tissue pogonion to skeletal change revealed 98% in group A, and 109% in group B. The double jaw surgery group characteristically revealed remarkable integ umental change in the upper lip area, while the one jaw surgery had major effects in the lower lip and soft tissue pogonion areas.

• The korean journal of orthodontics
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• v.38 no.2
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• pp.83-94
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• 2008

Purpose: The first objective of this study was to compare the upper midface morpholgy, focusing on the soft tissues, between skeletal Class III maloccusion patients with midfacial depression and the norm. The second objective was to estimate and analyze the change in the upper midface soft tissues following surgical correction with maxillary advancement by Lefort I osteotomy and mandibular setback by bilateral sagittal split osteotomy (BSSRO). Methods: The samples consisted of 34 adult patients (15 males and 12 females) with an average age of 21 years, who had severe anteroposterior discrepancy with midfacial depression. These patients had received presurgical orthodontic treatment and surgical treatment which consisted of simultaneous Lefort I osteotomy and BSSRO. Results: The correlation coefficient between changes in maxillary advancement and changes in Or' (soft tissue orbitale) was 0.599 (p < 0.05). Change in maxillary plane angle and vertical change of the maxilla were not correlated with the change in Or' (p < 0.05). The ratio of soft tissue change in Or' to maxillary advancement was 43.57 %, and 81.54 % in Sn. Regression equations between maxillary movement and Or' were devised. The $r^2$ value was 0.476. Conclusions: The majority of measurements in the upper midface in skeletal Class III maloccusions when compared to the norm, showed significant differences. In Class III malocclusion with midfacial depression, maxillary advancement produces soft tissue change in the upper midface.

• The korean journal of orthodontics
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• v.38 no.1
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• pp.41-51
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• 2008

Objective: The aim of this study was to compare the initial lateral cephalometric characteristics in two groups of patients: those that had mandibular setback surgery only and those that had mandibular setback surgery with advancement genioplasty. Methods: The lateral cephalograms of thirty-one patients were studied. Twenty-one Class III patients (group A) had only madibular setback surgery Twelve Class III patients (group B) had mandibular setback surgery with advancement genioplasty. Results: Differences between two groups were found in N-Me, ANS-Me, Occlusal Plane angle, Palatal Plane to U1, Mandibular Plane to L1, Mandibular Plane to L6, SN to U1, Sn-Stms, and Pog' projection. Compared to group A, group B showed more linguoversion and extrusion of upper incisors, more extrusion of lower incisors and lower first molar, and more steepness of the occlusal plane. N-Me, ANS-Me, and Sn-Stms were also longer in group B. But Pog' projection was shorter than group A. Conclusion: We conclude that certain initial lateral cephalometric characteristics may help indicate the inclusion of advancement genioplasty when mandibular setback surgery is planned in skeletal Class III patients.

• The korean journal of orthodontics
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• v.37 no.4
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• pp.272-282
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• 2007

The purposes of this study were to evaluate the nasolabial angle changes between closed lip position at centric occlusion and relaxed lip position at which the bite is open so that the lips do not touch and to elucidate the significance of the relaxed lip position for dentofacial diagnosis. Methods: The subjects consisted of 60 (35 Males, 25 Females) skeletal Class III malocclusion adult patients (mean age 23.3 years) with anterior crossbite. Results: In Class III malocclusion adult patients, there were significant differences in the nasolabial angle changes between closed lip position and relaxed lip position. Using the cluster analysis, the subjects were divided into three groups according to the pattern of nasolabial angle change: Group 1 (N = 27, 45%, $-8\;{\sim}\;1$), Group 2 (N = 30, 50%, $2^{\circ}\;{\sim}\;17$), and Group 3 (N = 3, 5%, over 18). Conclusion: The results showed that the pattern of the nasolabial angle change between closed lip position and relaxed lip position varies in skeletal Class III malocclusion patients. Thus, relaxed lip position should be taken into account when diagnostic records are obtained and analyzed to accurately to evaluate the facial soft tissues and predict facial esthetics after surgical-orthodontic treatment.