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This paper examines the relationship between roll rotation of the jaws and changes in alar base or lip line asymmetry in the coronal plane following orthognathic correction. The study involved patients with preoperative frontal alar base and lip line asymmetries greater than 0.5° (because it corresponds to the minimum asymmetry perception threshold) and underwent bimaxillary orthognathic surgery without (Group I) or with (Group II) genioplasty. The alar base angle (ABA), lip line cant angle (LLCA), maxillary cant angle (MxCA), and mandibular cant angle (MnCA) were measured using preoperative and 12 months postoperative cone beam computed tomography (CBCT) images. Thirty-four patients were included in the study. Significant correlations were found between changes in MxCA and ABA besides between changes in MnCA and LCA in Groups I (P = 0.016, P˂0.001, respectively) and II (P = 0.002, P˂0.001, respectively). The mean of the change in ABA/the change in MxCA and the change in LLCA/the change in MnCA ratios for Group I were 0.59 ± 1.57 and 0.73 ± 0.94, respectively, while those for Group II were 0.46 ± 3.70 and 0.39 ± 2.00, respectively. Angular measurements from jugular and mental foramina points, aligned with the bony midline, offer a convenient tool for predicting alar base and lip symmetry during bimaxillary orthognathic surgery planning., Competing Interests: Declaration of competing interest The authors declare no competing interests., (Copyright © 2024 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.)

Objective: To investigate the relationship between age, sex, length of upper lip and the exposure of maxillary central incisor. Methods: A total of 304 participants in normal occlusion (154 males, 150 females, aged 18-49 years) were recruited in this study from patients, visited the Medical Examination Center, Affiliated People's Hospital, Shanxi Medical University from January 2019 to August 2020. Participants were divided into 18-29 years old group (104, 53 males, 51 females), 30-39 years old group (110, 56 males, 54 females) and 40-49 years old group (90, 45 males, 45 females). Facial photography was used to record the facial state during the mandibular postural position, "che" pronunciation position and posed smile. The upper lip length, upper lip thickness and the exposure of maxillary central incisor were measured by ImageJ. The differences of measurement items in each group and the gender differences of each measurement item were analyzed. The length of upper lip and the exposure of upper central incisor in the mandibular postural position were analyzed by Pearson correlation. Results: In the mandibular postural position, the length of upper lip was (21.9±2.2), (22.5±2.5) and (23.1±2.2) mm in the 18-29 years old, 30-39 years old and 40-49 years old groups, and the length of upper lip in the 40-49 years old group was significantly larger than that in the 18-29 years old group ( P <0.05). The exposure of upper central incisor in the 40-49 years old group during the mandibular postural position, "che" pronunciation position and posed smile [(1.4±1.2), (4.7±2.4), (7.7±2.4) mm, respectively] were significantly lower than those in the 18-29 years old group [(2.3±1.4), (5.5±2.2) and (8.8±2.0) mm] ( P <0.05). The exposure of upper central incisor in the 30-39 years old group during the mandibular postural position and posed smile [(1.8±1.4), (8.2±2.0) mm, respectively] was significantly lower than those in the 18-29 years old group ( P <0.05). With the increase of age, the exposure of upper central incisor decreased gradually. In the same group, the exposure of upper central incisor in the female during the mandibular postural position and "che" pronunciation position (except 40 to 49 years old group) were significantly larger than those in the male ( P <0.05), and there was no statistically significant difference between the sexes in the posed smile ( P >0.05). There was a significant linear correlation between the exposure of upper central incisor and the length of upper lip at the mandibular postural position in normal occlusion aged 18-49 ( r =-0.325, P <0.01). Conclusions: Gender factor should be considered in the esthetic design of anterior teeth. The exposure of anterior teeth in the mandibular postural position and "che" pronunciation position is more valuable than that in the posed smile. The length of upper lip in normal occlusion aged 40-49 was significantly shorter than that aged 18-29, and the exposure of upper central incisors was significantly reduced.

Objectives: The purpose of this study was to compare the lip line cant (LLC) changes after 1 and 2-jaw surgery, and to evaluate the correlations of the craniofacial factors affecting LLC., Methods: The study subjects were selected (LLC amount within 1.5-6.0°) from among the patients diagnosed with Class III malocclusion who underwent one (n = 20) or 2-jaw surgery (n = 20). Cone beam computed tomography images were obtained immediately before the operation (T1) and 6 months after the operation (T2). Preoperative and postoperative craniofacial measurements were obtained., Results: The study subjects showed 3.12° LLC on average before undergoing 1-jaw surgery, and their LLC changed to 1.27° after the surgery. As for 2-jaw surgery, the subjects showed 3.38° LLC on average before the surgery and 0.98° after the surgery. LLC at pre-treatment may be more affected by a cant of the occlusal plane in the mandible than maxilla. In the comparison of the value of changes of LLC, the value of 2-jaw surgery was bigger than the value of 1-jaw surgery but the difference was statistically insignificant., Limitations: This study had a limitation in that the muscles were not considered. And the metal bracket or metal crown and bridge, however, can cause noise and blurring artifacts in CT, which can lead to a low resolution. And the limited number of the patients should be considered., Conclusions: In correlation analysis, both pre-surgery LLC and change of LLC have correlation with almost all the craniofacial measurement. Lip-line cant of patients with facial asymmetry has higher correlation with mandibular cant than with other cants. To improve the LLC, a surgical plan should be established to minimize the mandibular cant using the computer simulation as well as the maxillary cant.

Purpose: A new method inducing the physiologic rest position of the mandible using the lip contact position with the closed mouth have compared with those obtained using conventional methods of placing the mandible in the physiologic rest position., Methods: The lip contact position with the closed mouth as a method was investigated whether the technique was useful for determining the occlusal vertical dimension. The relationship between the space between the maxillary and mandibular front teeth in the lip contact position with the closed mouth and the areas of the prolabia was also investigated., Results: Median space between the maxillary and mandibular front teeth in the lip contact position with the closed mouth was 1.53mm, a value intermediate between the value of 2.16mm in the resting mandibular position obtained by the conventional technique and that of 1.33mm in the swallowing position. The coefficient of variation of the space in the lip contact position with the closed mouth was significantly lower than those in the resting mandibular position and in the swallowing position. A significant positive correlation was recognized between the space in the lip contact position with the closed mouth and the area of the prolabium of the upper lip., Conclusions: These results clarified that the lip contact position with the closed mouth obtained the excellent reproducibility comparing to the conventional methods. These findings suggested that the area of the prolabium of the upper lip might offer an effective index for individual determination of the correct free-way space., (Copyright © 2018 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.)

This article reports the case of a 24-year-old man with a large anterior open bite, mild mandibular crowding, increased overjet, no passive lip sealing, and Angle Class I malocclusion. The treatment results were achieved by mandibular molar intrusion using 1.8 × 8.5-mm mini-implants (C-implants) inserted between the mandibular first and second molars bilaterally. A 2.5-mm molar intrusion and open-bite closure occurred within 8 months. The multiloop edgewise archwire technique helped to intrude the posterior teeth. Total treatment time was 20 months. Fifty months postretention records are also presented. The patient achieved a suitable occlusion and satisfactory facial esthetics at the end of treatment and at the 50-month retention check., (Copyright © 2018 American Association of Orthodontists. Published by Elsevier Inc. All rights reserved.)

Following the surgical release of the mentalis muscle, lip incompetence and/or an increase in lower incisor exposure may be seen due to undesirable attachment of the muscle fibres. The aim of this study was to evaluate the extent of lip ptosis, lower incisor exposure, and other soft tissue changes following bone graft harvesting from the mandibular symphysis when the mentalis muscle is reapproximated precisely to its original position. Seventeen consecutive patients who underwent bone graft harvesting from the mandibular symphysis were included in this study. The mentalis muscle was isolated, identified, marked, and reapproximated precisely during the bone harvesting operation. Digital lateral cephalograms obtained preoperatively and at 6 months postoperative were analyzed and compared by paired samples t-test to determine the horizontal and vertical soft tissue changes in the lower lip and chin. Although the soft tissue thickness at soft tissue point B and at soft tissue pogonion had increased significantly at 6 months after chin bone graft harvesting, there were no significant changes in lower incisor exposure or other positional alterations of the lower lip (P<0.05). Precise reattachment of the mentalis muscle in its original position helps to avoid significant vertical positional changes in the lower lip. Increases in soft tissue thickness can be observed following bone graft harvesting from the mandibular symphysis., (Copyright © 2016 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Background: The purpose of this study was to compare the frontal lip cant changes in common facial asymmetry (FA) cases after simultaneous maxillomandibular distraction osteogenesis (DO) and mandibular DO with maxillary orthognathic surgery., Materials and Methods: Retrospective analysis of FA cases at tertiary craniofacial referral was performed. Patients of either gender with all medical imaging records and pre- and post-operative (1 year) facial photographs in natural head position were included in the study. The lip cant change was assessed by the ratio of the linear dimension between affected and unaffected side labial commissures and the bi-pupillary reference line. Difference between the pre- and post-operative ratio was analyzed. Statistical analysis was performed for the outcome. P ≤0.05 was taken as significant., Results: The mean preoperative measured value of the affected side was 0.845 ± 0.036 while the postoperative value was 0.95 ± 0.032. The effective change was 0.11 ± 0.044. The postoperative ratio compared with simultaneous DO case was 0.98 ± 0.06 while that of mandibular distraction with orthognathic surgery was 0.92 ± 0.08 (P = 0.048). The mean change of the simultaneous DO case was measured as 0.114 ± 0.041 while the same for the mandibular distraction with orthognathic surgery was 0.069 ± 0.035 (P = 0.013)., Discussion and Conclusion: The results indicate that the simultaneous DO yields more better frontal lip cant change between both halves than the mono-DO with orthognathic surgery. The mean change is much higher in the simultaneous DO cases indicating a more effective correction and desired result. The biological reason and lip musculature mechanism behind the response in both conditions are discussed.

Objectives: To evaluate the cephalometric changes in skeletal, dentoalveolar and soft tissue variables induced by Clark's Twin Block (CTB) in Class II, Division 1 malocclusion patients and to compare these changes in different cervical vertebral maturation stages., Methods: Pre- and post-treatment/observation lateral cephalograms of 53 Class II, Division 1 malocclusion patients and 60 controls were compared to evaluate skeletal, dentoalveolar and soft tissue changes. Skeletal maturity was assessed according to cervical vertebral maturation stages. Pre- and post-treatment/observation mean changes and differences (T2-T1) were compared by means of Wilcoxon sign rank and Mann-Whitney U-tests, respectively. Intergroup comparisons between different cervical stages were performed by means of Kruskal-Wallis test and Mann-Whitney U-test (p ≤ 0.05) ., Results: When compared with controls, there was a significant reduction in ANB angle (p < 0.001), which was due to a change in SNB angle in CS-2 and CS-3 (p < 0.001), and in SNA (p < 0.001) and SNB (p = 0.016) angles in the CS-4 group. There was significant increase in the GoGn-SN angle in CS-2 (p = 0.007) and CS-4 (p = 0.024), and increase in Co-Gn and Go-Gn amongst all cervical stages (p < 0.05). There was significant decrease in U1-SN and increase in IMPA amongst all cervical stages (p < 0.05). There was significant retraction of the upper lip in CS-3 (p = 0.001), protrusion of the lower lip in CS-2 (p = 0.005), increase in nasolabial angle in CS-4 (p = 0.006) and Z-angle in CS-3 (p = 0.016), reduction in H-angle in CS-2 (p = 0.013) and CS-3 (p = 0.002) groups. When pre- and post-treatment mean differences were compared between different cervical stages, significant differences were found for SNA, SNB and UI-SN angles and overjet. ., Conclusions: The Twin-Block along with the normal craniofacial growth improves facial esthetics in Class II, Division 1 malocclusion by changes in underlying skeletal and dentoalveolar structures. The favorable mandibular growth occurs during any of the cervical vertebral maturation stages, with more pronounced effect during CS-3 stage.

Objective: To evaluate the predictive accuracy of the SurgiCase CMF software in surgical simulation and prediction for mandibular asymmetry with 3-dimensional simulation and measurement., Methods: CBCT data of 27 patients with mandibular asymmetry were observed in CMF, and postoperative soft tissue physiognomy were predicted by simulating sagittal ramus osteotomy with or without genioplasty. The measurement parameters representing the symmetry of soft tissue were selected and the horizontal, coronal and sagittal planes were established. The results were analyzed by SPSS 19. 0. The overlap compared color grading charts were observed., Results: Angles between cheilions and the horizonta plane (Ch-Ch-FH) in the simulation and postoperative soft tissues are (2. 35 ± 1. 81)° and (1. 44 ± 1. 13)°. The angles constructed among subnasale, upper lip and lower lip (Sn-UL-LL) are (4. 02 ± 3. 05)° and (2. 59 ± 1. 64)°, showing statistically different (P < 0. 01, P < 0. 05), which means that predictive accuracy of the lip canting and lip vertical deviation is relatively low. Distance between gonioi and sagittal plane (Go'-MS), distance between gonion and pogonion (Go'-Pog') and angle betweer subnasale to menton and the horizontal plane (Sn-Me'-MS) are not statistically different, which mean! high predictive accuracy of mandibular angle and chin. By observing the overlap compared color gradin-) charts, the predictive accuracy is not good in the cheek, especially in the deviate side., Conclusions: The predictive accuracy of CMF system for patients with mandibular asymmetry is relatively high, but it is not good in the lip and cheek. The software improvement is still necessary.

After orthognathic surgery the forehead remains unchanged. To produce facial harmony, the planned projection of the maxillomandibular complex must be placed in the correct relations to the unchanged position of the forehead. We have compared the anterior soft tissue projection of the maxillomandibular complex relative to the forehead after Le Fort I advancement surgery for correction of maxillary hypoplasia with that of a local reference group chosen by lay assessors. We retrospectively studied 32 patients (16 men and 16 women) all of whom had previously been treated by Le Fort I maxillary advancement. In addition a panel of 8 lay assessors selected a reference group of 24 women and 16 men. Standard profile photographs were taken, and horizontal measurements made, of several landmarks from a true vertical line (TV) passing through glabella. Together with facial harmony values these were compared between the groups. The orthognathic group had significantly more anterior mandibular projection relative to the forehead than the female reference group (p=0.03). As a result half of the horizontal harmony values were smaller in the orthognathic group. For men the position of the mandible, particularly the chin, was acceptable even though it was positioned more anteriorly. We have provided values for maxillomandibular projection derived from lay assessors and identified areas where differences from those of a reference group were detected. The projection of the mid and lower face of the local reference group to the forehead should guide preoperative planning., (Copyright © 2014 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.)

Objective: To determine the mean visible labial length of maxillary and mandibular anterior teeth at rest., Study Design: Cross-sectional study., Place and Duration of Study: Department of Prosthodontics, Dr. Ishrat-ul-Ebad Khan Institute of Oral Health Sciences, Karachi, from October 2012 to March 2013., Methodology: A total of 200 subjects were included. Measurements were carried out using digital caliper from the border of the lip to the incisal edges of incisor and to the cusp tip for the canines. The length of the upper lip was measured from subnasale to stomion. Statistical analyses were performed by Mann Whitney-U test and Kruskal Walli's test., Results: The age of the participant ranged between 20 and 65 years. At rest, females significantly displayed more of the maxillary central incisor (2.93 ± 1.57 mm; p=0.003), lateral incisor (1.87 ± 1.12 mm; p=0.005) and canine (0.59 ± 0.62 mm; p=0.031). With increasing age, the amount of maxillary anterior teeth visible at rest significantly decreased (p < 0.001), and increased for the mandibular teeth (p < 0.001). Subjects with shorter upper lips significantly displayed more maxillary anterior incisor structure than subjects with longer upper lip (p < 0.001)., Conclusion: Females displayed significantly more labial length of the maxillary anterior teeth. The mean visible labial length of maxillary anterior teeth significantly decreased with increasing age and increased for the mandibular teeth. As the upper lip length increased, the mean visible labial length of maxillary anterior teeth significantly decreased.

Summary: The aim of this retrospective study was to evaluate bimaxillary protrusion among Moroccans and to compare the Moroccan population with other Arabic, Caucasian, and Mediterranean populations. Cephalometric radiographs of 102 Moroccan adult university students (73 females and 29 males, mean age: 21 years 6 months +/- 1 year 6 months) with a normal occlusion were traced. Fifteen measurements concerning the upper and lower incisors, upper and lower lips, and the Frankfort to mandibular plane angle were assessed. Statistical analysis of the data was undertaken using independent t-tests. Eight angular and six linear measurements were statistically significantly different compared with Caucasian cephalometric norms (P < 0.001). Significant differences were observed compared with other adult Arabic populations (Palestinians and Saudis) and with Turkish Anatolian adults. Relative to Caucasian cephalometric norms, Moroccans showed bimaxillary protrusion and, therefore, these norms cannot be applied to Moroccan faces. In general, there was a great similarity in incisor position between the Moroccan and Saudi populations.

Objectives: To test the hypothesis that there is no difference in the morphology of the lips and to determine the degree of improvement in the smile after orthognathic surgery for Class III malocclusion., Materials and Methods: The sample subjects included 30 adult female patients with dento-skeletal Class III malocclusion and 28 adult female volunteers with normal occlusion. Frontal facial photographs were taken before and after treatment, and 35 landmarks were placed on each tracing made from the frontal facial photograph. Thereafter, the landmarks were digitized into an x and y coordinate system with the subnasal point as the origin. The pretreatment rest and smile conditions were compared with the posttreatment conditions, respectively, using paired t-tests. In addition, two sample t-tests were used to test for differences between groups., Results: Both the upper and lower lips in the smiles of the Class III pretreatment group were positioned downward, and the upward movement of the upper lip and commissure points were smaller compared with the control group. When smiling, the horizontal direction of the mouth corners was statistically significantly different between the pretreatment and posttreatment conditions, whereas these were wider in the posttreatment than in the pretreatment conditions. These characteristics of the Class III smile improved after orthognathic treatment, but the differences with the control group remained unchanged immediately after treatment., Conclusion: The hypothesis is rejected. The soft tissue morphology of patients with dento-skeletal Class III malocclusion shows a significant improvement after orthognathic surgery.

The purpose of the present study was to determine the location of the mental foramen (MF) based on soft- and hard-tissue landmarks, to facilitate prediction of the location of this structure during facial and dental surgery. Forty-two hemispheres of 21 adult cadavers (16 men and 5 women; aged 30-75 years) were dissected to expose the MF. The locations of the MFs were evaluated with direct and photographic measurements. Most of the MFs presented a single foramen (95%), except for only 2 cases with double foramina (5%). The MFs localized 23.38 +/- 2.00 mm inferior and 3.55 +/- 1.70 mm medial to the cheilion in the front view while 23.59 +/- 2.11 mm inferior and 7.19 +/- 3.03 mm posterior to the cheilion in the lateral view. Based on the hard-tissue landmarks, we found that most of the MFs localized inferior the second premolar in most of the cases (73.8%), and the MFs localized 23.34 +/- 2.39 mm below the cusp tip of the second premolar, 16.56 +/- 2.53 mm below the inferior alveoli, and 15.56 +/- 1.74 mm superior the bottom of the mandible. The position of the MF varied from 8.7 degrees medial to 15.5 degrees posterior in the vertical angle with the change of surgical body position from supine to lay-side position. Our results may provide a more detailed information to predict the location of the MFs.

Purpose: The purpose of this study was to determine the relationship between the changes of soft and hard tissues after modified anterior segmental osteotomy on the maxilla and mandible and to evaluate unintended facial changes using cephalometric and photometric analyses., Materials and Methods: The subjects included 29 women and 1 man (22 to 50 years of age) who were diagnosed as bialveolar or bimaxillary protrusion and underwent modified anterior segmental osteotomy on the maxilla and mandible. Lateral cephalograms and lateral and frontal photographs taken preoperatively and postoperatively were analyzed., Results: There was a significant change in all soft and hard tissue parameters except the labiomental angle. The ratio of upper lip to maxillary incisor retraction was 0.67:1 and the ratio of lower lip to mandibular incisor retraction was 0.89:1. Nasolabial angle and philtrum length were increased, and vermilion length and lip width were decreased. Nasal change could be kept as small as possible, although slight widening of the nasal width and anti-tip rotation of the nasal tip were observed., Conclusion: Anterior segmental osteotomy might be recommended as the treatment modality of choice in patients with bimaxillary and/or dentoalveolar protrusion. Because the technique is simple, postoperative complications are minimal, relapse is limited, and soft tissue changes in response to surgery are more predictable.

Purpose: The aim of this study was to assess long-term changes in position of soft tissue landmarks following mandibular advancement and setback surgery., Materials and Methods: Twenty-seven patients (14 women, 13 men; mean age, 36 years) who had undergone either mandibular advancement (15 patients) or setback surgery (12 patients), were available for a long-term follow-up an average of 12 years postoperatively. In all of these cases, lateral cephalometric radiographs taken immediately before operation, at 1 week, 14 months, and 12 years postoperatively, were studied., Results: During the 14 months postoperatively, soft tissue chin and mentolabial fold followed its underlying hard tissue in all patients. A continuous skeletal relapse was observable 12 years after mandibular advancement, but soft tissue chin moved more in an anterior direction. After mandibular setback, soft and hard tissue landmarks remained almost unchanged. Over the entire observation period, a thickening of soft tissue at pogonion was generally seen, and particularly a thickening of the whole chin in the setback group. All patients showed a significant lengthening and thinning of the upper lip. In all except 2 males, the patient's body weight increased markedly., Conclusion: In contrast to the immediate postoperative stage, soft tissue changes observed an average of 12 years after the primary operation do not directly follow the movements of the underlying skeletal structure. The soft tissue profile changes observed over such a long term seem to be influenced not only by the underlying skeletal structure but also by other factors such as weight gain and aging process.

Objective: The objective of this study was to determine alternative ratios of soft-to-hard tissue movement after mandibular setback, taking skeletal relapse and differing patterns of facial divergence into account., Study Design: Thirty patients were analyzed cephalometrically over a mean follow-up period of 14 months., Results: The relationship between skeletal and soft tissue movements in the mentolabial folds and at the pogonion was 1:1. Final skeletal relapse was 0.8 mm at the B-point and 0.5 mm at the pogonion. Hence, the alternative ratios were 81% and 68%, respectively. The alternative ratio for the mentolabial sulcus was considerably lower in the low- than in the high- and medium-angle groups of patients. However, there was no statistically significant difference between the patient groups with different facial patterns., Conclusion: When the smallness of the measured relapse and the tracing error are taken into account, the difference between the alternative and the conventional ratios was insignificant.

The objective of this cephalometric study was to assess long-term changes in the soft tissue profile following mandibular setback surgery and investigate the presence of factors that may influence the soft tissue response to skeletal repositioning. The subjects enrolled were 80 consecutive mandibular prognathism patients operated with bilateral sagittal split osteotomy and rigid fixation. Lateral cephalograms were taken at 6 occasions: immediate presurgical, immediate postsurgical, 2 and 6 months postsurgical, and 1 and 3 years postsurgical. The subjects were grouped according to gender and magnitude of setback. Ratios of soft tissue to hard tissue movements were calculated for the subgroups. Females generally demonstrated greater ratios than males with a statistically significant difference for the upper lip and chin (P < .05). Postsurgical alterations in the profiles were more predictable in patients with larger setbacks compared to patients with smaller ones. Skeletal relapse had a profound influence on long-term profile changes. Based on these findings, it is proposed that the database used in prediction software be adjusted to account for such factors in an attempt to improve the accuracy of computerized treatment simulations.

Purpose: The prediction of profile changes as a result of orthognathic surgery remains a problem during preoperative planning because of the different relative movements of the hard and soft tissues. This study analyzed the changes in soft tissue profile after sagittal split ramus osteotomy and mandibular setback., Patients and Methods: Soft tissue changes relative to hard tissue references were recorded by means of computer-supported measurements of preoperative and postoperative standardized lateral skull radiographs of 60 Class III patients., Results: An average backward transposition of the osseous pogonion of 7.1 mm was recorded. Relative to movements of this reference point in the sagittal plane, the soft tissue pogonion moved 83.9%, the soft tissue menton moved 98.9%, the labrale superior moved 32.0%, the stomion moved 45.2%, and the labrale inferior moved 79.6%. The same measurements were performed in the vertical plane, and changes in soft tissue references were analyzed. There was a marked difference in soft tissue changes after mandibular retropositioning when compared with results after mandibular advancement reported in the literature., Conclusion: It was concluded that it is of great importance to consider both the direction and the surgical method when predicting profile changes in the vertical as well as sagittal plane after orthognathic surgery.

Purpose: The purpose of this investigation was to test the hypothesis that the mandible rotates around the same point during maxillary impaction surgery as during initial jaw opening. This point, called the center of mandibular autorotation (CAR), could then be used to predict mandibular position and to decide whether only maxillary impaction would be needed to correct the occlusion and the facial profile., Patients and Methods: Preoperatively, two lateral cephalograms were obtained from a consecutive series of 20 patients who underwent maxillary impaction without concomitant mandibular ramus osteotomy. One cephalogram was taken with the mandible in centric relation using a wax bite wafer and another with a jaw opening of 10 mm using a fabricated acrylic bite block with the mandible manipulated to its most retruded position. The CAR was calculated before and after jaw opening using the Rouleaux method on the lower incisor and gonion point. A third lateral cephalogram was taken within 2 days postoperatively. The postoperative lower incisal point was then transferred to the first cephalogram using cranial base superimposition., Results: When the preoperative and postoperative distances between CAR and incisal point were compared, there was no significant difference between these distances, proving the hypothesis., Conclusions: The method used is a practical and precise way to determine the center of mandibular autorotation on an individual basis. The center of rotation during initial jaw opening is the same as during impaction surgery.

The response of the entire facial soft tissue to correction of mandibular hyperplasia was evaluated in 25 patients by moiré topography. Postoperative changes were quantitatively analyzed by a computer-aided superimposition technique. Posterior displacements occurred in the lower third of the face. A marked retraction was observed around the chin, but the changes gradually decreased in the coronal and posterior directions with distance from the chin. The upper lip was slightly reduced; however, no direct effect was found in the cheeks. The results of this study constitute a database that, if used in conjunction with an interactive imaging system, would allow surgeons to predict accurately the postoperative appearance of the patient.

The stability and the effect on the soft tissue profile of mandibular setback with sagittal split osteotomy and rigid internal fixation was studied prospectively in 29 consecutive patients, 17 to 55 years old, who had mesial occlusion. Profile cephalometric radiographs were taken immediately before and short after surgery as well as 14 months postsurgically. The mean setback of the mandible 1 to 8 days after surgery was 6.0 mm. On average, there was also a small decrease in the anterior facial height. The setback relapsed an average of 1.1 to 1.3 mm, so that at the follow-up the mean net effect was 80%. In eight patients, however, the mandible had retruded slightly further. During the follow-up period there was a further small decrease in the anterior facial height. The net effects on the labial fold and the soft tissue chin were closely correlated with those on their underlying hard structures. On average, the labial fold and the chin followed the hard structures to 106% and 107%, respectively. The mean net effect for the lower lip was only 88% of the setback of the mandibular incisor. The soft tissue facial height followed the decrease in the skeletal facial height to 60%. The setback procedure also affected the upper lip, which, on average, retruded and lengthened 1.0 to 2.0 mm.

Surgical mandibular advancement results in many soft tissue changes. The purpose of this study was to quantify the changes seen in the cervicomental angle and the lip-chin-throat angles in response to mandibular advancement, as well as hyoid bone positional changes. As a result of statistical analysis of hyoid bone and soft tissue linear and angular changes, prediction models are presented as to the soft tissue response to mandibular advancement in the cervicomental region.

Many evaluations of soft tissue changes after orthognathic surgery have been undertaken, and many correlations of soft tissue to hard tissue movements have been established. These studies have not, however, specifically discussed the long-term stability or characteristics of the soft tissue changes. The objectives of this study were (1) to determine the long term stability of soft tissue changes 5 years after LeFort I osteotomy, (2) to determine reliable correlations, if any, of soft tissue changes to bony movements effected in surgery, and (3) to determine the predictability of soft tissue changes as an aid to orthodontic treatment planning. Cephalometric data from 25 patients who were treated with LeFort I osteotomy with or without a concurrent mandibular procedure were analyzed retrospectively. Cases were selected from the patient records of the Department of Oral Surgery of the Vrije Universiteit in Amsterdam, the Netherlands. These patients were followed up at four time points, the last being a mean of 6.1 years after surgery. Analysis of stability data revealed that most horizontal and vertical soft tissue change after LeFort I surgery occurred in the first year after surgery. Significant (> 10%) change continued to occur for subnasale, labrale inferius, upper lip protrusion, lower lip protrusion, and soft tissue convexity during the subsequent 5 years. Hard tissue to soft tissue correlations were calculated and ratios of soft tissue to hard tissue movement were determined for appropriate hard and soft tissue landmarks at four time intervals. Reliable correlations of hard tissue change at surgery to 5-year soft tissue change could be made for 10 variables, which was considerably less frequently than for 1-year soft tissue change. The relatively low reliability of long-term prediction correlations suggests that soft tissue movements may be more independent of hard tissue over time. One-year prediction values were similar to 5-year values and thus could be used for prediction purposes in orthodontic treatment planning. Most short-term hard to soft tissue correlations found in the present study were in the range of those established by previous authors. Long-term hard tissue to soft tissue correlations gave higher ratios of soft tissue movement secondary to maxillary surgery, approaching ratios of 1.0:1.0 for some variables. This finding, as well as the long-term stability data, suggest that soft tissue settling or equilibrium after surgery may take several years to complete.

A three-dimensional soft tissue study of the results of surgery in a group of 16 skeletal Class III adult patients following orthognathic surgery was carried out using laser scans (Arridge et al., 1985). The patient group was compared to a control group of the same population. Laser scans were taken prior to surgery, 3 months post-surgery, and at least 1 year after retention. Preoperative comparison to the control groups revealed that the facial disproportion related to both the maxilla and the mandible. Le Fort I advancements resulted in broadening of the lateral aspects of the nose, advancement of the dorsum, and overcorrection of the alar bases. There was a degree of change over the cheeks bilaterally, because of alterations in the general drape of the soft tissues. There was a degree of overcorrection in the female group following mandibular set back but the male group were still more prognathic, when compared to the control group. There was a marked degree of relapse in the mandible from 3 months to 1 year postoperatively, with a resultant anterior movement of the maxillary arch. Laser scanning has proved to be a simple non-invasive method of measuring three-dimensionally, and is a very useful tool in auditing surgical outcome and measuring surgical relapse.

The finite element method is used to predict facial deformation following orthognathic surgery for mandibular prognathism. The deformation is calculated using a model that assumes severe skeletal class III malocclusion. The possibilities and limitations of this method for clinical application are described.

The purpose of this study was to evaluate the amount, direction, and predictability of the soft tissue changes associated with simultaneous maxillary impaction and mandibular advancement surgery. The results suggested that the soft tissue responses were similar to those seen in single jaw procedures, with the exception of the changes seen in the nasolabial angle and in the area of the lower lip and chin. The type of soft tissue manipulation employed, in particular the use of the alar base cinch suture and V-Y closure techniques, were important factors in determining the response of the upper lip to the surgery. The maxillary soft tissues moved forward 90% of the hard tissue change and showed 20% shortening of the upper lip, with the changes in the nasolabial angle being due primarily to the degree of the maxillary rotation. A predictable progressive increase was seen in the horizontal movement of the mandibular soft tissues ranging from 73% of the hard tissue change at the lower lip to 100% at pogonion. The vertical movement of the mandibular soft tissue was greater than that of underlying hard tissues, particularly in the area of the lower lip as it was freed from the effects of the maxillary incisors.

The purpose of this study was to compare cephalometrically the differences in soft-tissue profile changes produced by intraoral ramus and anterior subapical osteotomies for the treatment of Chinese patients with class III malocclusion. Thirty-seven Chinese adults whose class III malocclusion was treated either with an intraoral ramus (group A) or an anterior subapical (group B) osteotomy were selected for the study. Serial lateral cephalograms taken presurgically (T1) and at least 6 months postrentention (T2), showed marked improvement in the soft-tissue profile in both groups. Although the percentage response of soft- to hard-tissue movement was similar at lebrale inferius, the response at soft-tissue point B was found to be statistically less in group B than in group A (P less than .05). Although the correlation between the upper lip response to mandibular ramus setback in group A was weak (r = 0.11), there appeared to be a relatively strong correlation between posterior movement of the upper lip and the magnitude of the lower segmental setback (r = 0.65). The differences in soft- to hard-tissue response with the two osteotomy procedures appear to vary with those reported in whites. This study emphasizes the need for different prediction ratios of soft- to hard-tissue movement in different racial types.

In 31 surgically treated Class II patients, several features were studied on cephalograms, before and after a mandibular lengthening osteotomy had been performed. After surgery, hardly any changes in the soft tissue thickness were recorded. In Class II patients, the upper part of the lower lip is situated at a larger distance from the skull, since its position is influenced by the antero-posterior position of the upper incisors and the overjet. The postoperative decrease of this distance was caused by the fact that the upper part of the lower lip failed to follow the total amount of forward mandibular displacement. This is due to the fact that the antero-posterior position of this part of the lip is touching the upper incisors and therefore does not follow the amount of mandibular advancement. The labiomental fold flattens, because the lower part of the lower lip completely follows the forward displacement of the mandible, whereas the upper part remains almost unchanged. This flattening can be favourable in Class II patients showing a very deep fold, as the surgical intervention tends to normalize the depth. In open bite profiles on the contrary, this effect could be unfavourable. The combination of the lengthening osteotomy with a genioplastic intervention, could mask this unfortunate result. Due probably to the presence of orthodontic retention devices and the intercuspidation of teeth, normal occlusal relations remained one year after surgery. A relapse of about 30 per cent was found in the mandibular bases. In order to anticipate this, some surgical overcorrection could be considered.

It has been demonstrated that there are reliable methods of predicting the ultimate position of the lower incisor and the soft tissue. However, the concept of treating this tooth to any one number for every individual was not supported by the evidence. An optimum system would allow the clinician to select and combine factors from all methods and arrive at a balance of esthetics, function, and stability, obtaining a suitable compromise for his individual patient. This is undoubtedly attempted intuitively by many experienced clinicians.

An investigation was undertaken to evaluate the soft-tissue changes of the lips as a result of dentoalveolar setback procedures performed to reduce bimaxillary dentoalveolar protrusion in black patients. Lateral head films of 14 adult patients taken preoperatively and postoperatively were compared to evaluate soft- and hard-tissue changes. A stepwise regression analysis with hard-tissue changes, initial interlabial gap, lip thickness, and lip area as predictor variables was performed to assess their influence on the change in an associated soft-tissue point. Upper lip thickness and horizontal change in PR accounted for 60% of the horizontal variance in the upper lip at SLS, and horizontal change in PR accounted for 80% of the horizontal variance in LS. Lower lip area accounted only for 28% of the horizontal variance in the lower lip at LI. Vertical changes of the upper lip were small and could not be predicted. Vertical changes of the lower lip were small but predictable: IL and lip thickness accounted for 75% of the vertical variance in the lower lip at ILS, and ID accounted for 58% of the vertical variance in LI.

Fifty-one oral and maxillofacial surgeons, 52 orthodontists, 51 orthognathic surgery patients, and 100 lay persons evaluated life-size lateral photographs of two male and two female subjects that had been altered to simulate varying amounts of surgical correction of mandibular retrognathism and prognathism. A horizontal change at pogonion of less than 4 mm was generally not recognized by more than half of the lay groups. The dental groups were more accurate, but even they did not achieve better than 80% recognition until 6 mm of change. Both the dental and lay groups recognized change more easily in the female and the prognathic subjects. When asked which feature appeared changed, dentists generally indicated the chin and lay groups the lips.

Bimaxillary surgery involving mandibular set-back and maxillary advancement has been performed on eight patients with severe prognathic mandibles and in two patients with pronounced retropositioning of the maxilla. The combined surgical approach turned out to give a very satisfying result both from the functional and aesthetic points of view. Whereas a certain skeletal horizontal relapse occurred in the mandible and a vertical one in the maxilla, the occlusal stability was maintained in all but one case. A good postoperative occlusion obviously retains the teeth in position. The soft tissue adaptation and final configuration postoperatively takes a long time, and should if possible be subjected to more sophisticated analysis before surgery. The bimaxillary approach with step-wise surgery, using an intermediate wafer is, in our opinion, a good solution to marked malpositions and in many cases preferable to single jaw surgery.

Changes in lip morphology and area, measured in two dimensions from standardized lateral head films, were assessed in a series of twenty adults at three times: pre-surgically, 8--14 months post-surgically, and a long-term follow-up at 5--7 years. All individuals received the same, single surgical procedure (Obwegeser sagittal split for correcting mandibular prognathism. Upper and lower lip changes were quantified as millimetres displacement of the lip centroid vertically and horizontally, plus changes in cross-sectional area. Direction and amount of change, its dependency on the amount and kind of surgically induced symphyseal changes, and the intercorrelations among lips and among lip and symphysis variables were statistically evaluated, both univariately and multivariately. Three measures are made of symphysis change: horizontal and vertical repositioning and amount and direction of rotation. Horizontal repositioning primarily affected the lengthening and areal increase of the upper lip. Vertical repositioning had its major influence in the height and cross-sectional area of the lower lip: a superior shift of the mandible made the lower lip shorter, more protrusive and smaller in area; an inferior shift produced an increase in lower lip height with increased area. The third variable, symphyseal rotation, had its greatest influence on the labial-lingual shift of the upper lip's centroid. The long-term follow-up showed little change from the 1 year post-operative conditions; equilibrium of the soft tissue components was then achieved fairly soon after surgery.

Cephalometric analysis of the facial soft tissue profile after surgical correction of skeletal Class III malocclusion performed either in the ascending ramus or in the mandibular body in 33 patients showed a close correlation between the horizontal movements of the soft tissue landmarks and those of the underlying skeletal and dental structures. In the vertical direction, the changes were more variable. A comparison of these results with the soft tissue profile of normal persons indicated that a natural appearance could be achieved after correction of Class III malocclusion by combined surgery and orthodontic treatment.

Using a radiographic technique, the depth of the vestibular fornix in the lower anterior region was determined for 100 periodontally healthy subjects. The width of attached gingiva was measured clinically. The vestibule in the mandibular anterior region was found to be approximately uniform in depth for each individual from canine to canine, being reduced where there were frenal and muscle attachments. The depth, measured from the gingiva to mucobuccal fold, varied from 2.5 to 11.5 mm; and. measured from the crest of the lip to mucobuccal fold, varied from 10 to 29 mm. The proportion of the vestibule, measured from gingiva to mucobuccal fold, occupied by attached gingiva, varied from a mean of 34% in the canine region, to approximately 60% in the lateral incisor region, and to approximately 55% in the central incisor region. The minimum depth of the vestibule determined was 2.5 mm, and this was associated with a zone of attached gingiva 1 mm wide. Considering that all subjects in this study were periodontally and gingivally healthy, it would appear that satisfactory periodontal and gingival health may be maintained even where the vestibule is shallow.

The traditional orthodontic and/or orthognathic surgical management of the Class II deep-bite case with a low mandibular plane angle has often been difficult; optimal esthetic results have not always been achieved, and long-term stability was often unpredictable. Many of these patients may benefit functionally and esthetically from appropriate orthodontic treatment and double-jaw surgical intervention to reorient the occlusal plane toward normal (8 degrees +/- 5 degrees to Frankfort horizontal) by moving the posterior maxilla and mandible superiorly and correcting into a Class I skeletal and occlusal relationship. As the occlusal plane angulation is increased, the upper incisor angulation decreases, the lower incisor angulation increases, the chin rotates down and backward relative to the lower incisor occlusal plane tips, and the mandibular plane angle increases. The principle of changing the occlusal plane has provided a means to improve the functional and esthetic results for the correction of this type of facial deformity, as well as many others.

Twenty-five patients with true bimaxillary protrusion (class I) were analyzed cephalometrically before and after combined anterior maxillary and mandibular subapical osteotomies to determine the exact changes in the facial soft tissue profile, the degree of predictability of these changes, and the extent of improvement in the postoperative facial soft tissue profile.

A radiographic method of measurement of the depth of labial vestibule in the mandibular anterior region has been described. Contrast medium was applied to the lip and mucobuccal fold and radiopaque marker attached to the labial surface of each tooth. The head was positioned in a craniostat and a posterior-anterior radiograph exposed. The radiopaque boundaries of the vestibule showed on the radiograph so that they could be measured. Statistical analysis showed a recording error of 0.6 mm and an observation error of 0.29 mm, which are within the range of error acceptable for this type of recording technique.

The relative movement of the soft and hard tissues were studied in 41 Class III cases treated by mandibular surgery. Lateral head films were traced and the hard and soft tissue changes were measured against vertical and horizontal reference lines. In 26 cases changes occurring more than 1 year after surgery were studied. It is concluded that the soft tissues move consistently slightly less than the underlying hard tissues and also that a change in form of the lips occurred. Prediction of profile changes by the cutting up of profile photographs is unlikely to given an accurate picture of the soft tissue profile response.

The functional genioplasty is an osteotomy-ostectomy of the anterior mandible which reduces excessive lower anterior facial height to 55% of the total anterior facial height. The procedure is indicated particularly when one factor contributing to the long-face syndrome is vertical excess of the anterior mandible. The surgical technique involves creation of a tenon and mortise which not only preserves the insertions of both the labiomental muscles and at least some of the suprahyoid muscles but also improves the stability of transosseous fixation. Superior repositioning and advancement of the chin and myocutaneous structures produce both functional and esthetic benefits for the patient.

Sophisticated treatment planning for those individuals with severe dental and facial disproportions requires accurate prediction of posttreatment results. Preand posttreatment cephalometric X-rays for a group of twelve patients treated by a combined orthodontic-oral surgical approach were evaluated. The surgery was of either the standard mandibular subapical osteotomy or Kole type of procedure. Surgical repositioning of the anterior mandibular alveolus resulted in various changes in hard tissue and soft tissue profile. In summary, these changes were: 1. Decreased lower facial height. 2. More relaxed lip posture as revealed by an increased superior vermilion lip length and decreased inferior vermilion lip length. 3. Stomion moved inferior and posterior relative to the lower facial plane. 4. Superior labial sulcus became less concave. 5. Inferior labial sulcus became more concave. 6. Superior vermilion and inferior vermilion moved posterior relative to the lower facial plane. 7. Chin radius and lip-chin-throat angle decreased. 8. Overbite and overjet increased while Wits analysis decreased. 9. Facial contour angle was unchanged. Changes were similar for both standard subapical and Kole groups with the main difference being a greater reduction in facial height with the Kole group.