Appearance on face reading (cheek line) after orthognathic surgery

The cheek line (face reading) is an aesthetic element of the facial profile. The purpose of our study was to investigate the changes in the cheek line after mandibular setback surgery. Forty patients (20 female and 20 male, mean (SD) age 22 (5) years) were diagnosed with mandibular prognathism and treated by intraoral vertical ramus osteotomy alone. Cephalograms were obtained before operation (T1), at least a year postoperatively (T2), and final surgical changes over a year (T2-T1). The cheek line and landmarks (soft and hard tissues) were compared using the paired t test. The hypothesis was that the cheek line did not change significantly after mandibular setback. At the time of the final follow-up (T2-T1), the mean (SD) horizontal setback of pogonion (Pog) was 12.3 (3.5) mm for women and 11.7 (4.3) mm for men. The ratios of soft:hard tissue, labrale inferius:incisor inferius, labiomental sulcus:point B, soft tissue Pog:Pog, and cheek point:Pog in women were 0.96, 0.98, 0.98, and 0.08, and in men 0.91, 1.01, 0.94, and 0.13, respectively. The nasolabial and cervicomental angles in women were significantly increased by 11.1° and 11.4°, respectively, and in men the nasolabial angle was significantly increased by 11.1° and the mentolabial angle reduced by 9.9°. The cheek line (T2-T1) was moved significantly forwards. The hypothesis was therefore rejected. In conclusion, the cheek line was advanced significantly after isolated mandibular setback.     

Evaluation of soft tissue profile following intraoral ramus osteotomy in Chinese adults with mandibular prognathism

Twenty-five Chinese adults with mandibular prognathism were treated with either the intraoral vertical subcondylar osteotomy or the bilateral sagittal split ramus osteotomy. The patients were kept in maxillomandibular fixation for 6 to 8 weeks while osteosynthesis was achieved with the use of intraosseous wiring. Serial lateral cephalograms were taken presurgery and between 12 and 26 months postsurgery, and specific soft and hard tissue points were digitized on a computer. The mean mandibular setback postsurgically was 8.4 +/- 3.2 mm, with a 5.2-degree reduction in point A-nasion-point B angle. Posterior movement of pogonion, point B and the mandibular incisal edge was accompanied by posterior movement of 95% at soft tissue pogonion (r = .96), 89% at soft tissue point B (r = .83), and 67% at labrale inferius (r = .81), respectively. The correlation between changes in the labrale superius and mandibular setback appeared to be dependent on both the amount of mandibular setback and the degree of mandibular rotation during the setback surgery. The presently reported ratios of the soft tissue response to hard tissue movement vary from those reported in white patients by other researchers, which confirms the need for different ratios for different racial types.     

Long-term stability of mandibular setback surgery: a follow-up of 80 bilateral sagittal split osteotomy patients

The objective of this cephalometric study was to evaluate skeletal stability and time course of postoperative changes in 80 consecutive mandibular prognathism patients operated with bilateral sagittal split osteotomy (BSSO) and rigid fixation. Lateral cephalograms were taken on 6 occasions: immediately preoperative, immediately postoperative, 2 and 6 months postoperative, and 1 and 3 years postoperative. The results indicate that BSSO with rigid fixation for mandibular setback is a fairly stable clinical procedure. Three years after surgery, mean relapse at pogonion represented 26% of the surgical setback (19% at point B). Most of the relapse (72%) took place during the first 6 months after surgery. Clockwise rotation of the ascending ramus at surgery with lengthening of the elevator muscles, though evident in this study and apparently responsible for the early horizontal postoperative changes, does not seem to be associated with marked relapse. Changes occurring in some of the younger patients between 1 and 3 years postoperatively are likely to be manifestations of late mandibular growth.     

Bilateral sagittal split osteotomy for correction of mandibular prognathism: long-term results.

PURPOSE: To identify the long-term maxillomandibular changes after surgical correction of mandibular prognathism using bilateral sagittal split osteotomy (BSSO). PATIENTS AND METHODS: Twenty patients who underwent BSSO to setback the mandible and had cephalometric radiographs taken preoperatively and postoperatively at 6 weeks, 1 year, and long-term follow-up (mean, 28 months). The cephalograms were traced and measured to determine the operative and postoperative changes. Correlation analyses were performed to see the relationship between the magnitude of setback and the amount of long-term postsurgical change at B point and pogonion. RESULTS: The mean surgical setback was 8.2 mm at B point and 8.8 mm at pogonion. The mean long-term horizontal relapse was 2.3 mm (28.0%) at B point and 3.0 mm (34.1%) at pogonion. Out of 20 patients, 12 (60.0%) relapsed horizontally greater than 2 mm at B point and 13 (65.0%) at pogonion. The mean vertical surgical changes showed downward displacement of B point (2.3 mm) and pogonion (2.0 mm). The mean long-term vertical relapse was 1.6 mm (69.6%) at B point and 1.7 mm (85.0%) at pogonion. CONCLUSION: There was no correlation between the magnitude of setback and the amount of relapse at B point and pogonion. However, there was significant correlation between the magnitude of vertical, downward surgical displacement and the amount of vertical relapse at B point and pogonion. The majority of the maxillofacial changes occurred within 1 year postoperatively.     

Differences in soft tissue profile changes following mandibular setback in Chinese men and women.

PURPOSE: This study investigated the soft tissue profile changes after surgical correction of mandibular prognathism in Chinese patients and evaluated the sex differences in the ratios of soft tissue to hard tissue change. PATIENTS AND METHODS: Forty-three adult Chinese patients (18 men and 25 women) with mandibular prognathism were treated by intraoral oblique or vertical ramus osteotomy. Lateral cephalometric radiographs were taken presurgically and between 6 to 12 months postsurgically, and specific soft and hard tissue points were digitized and analyzed with a computer-aided system. RESULTS: As a result of surgical setback of the mandible, the soft tissue to hard tissue change ratios were: Li:Ii = 0.71:1, Si:B = 0.90:1, Pg':Pg = 0.94:1 for the males; and Li:Ii = 0.82:1, Si:B = 0.92:1, Pg':Pg = 1.06:1 for the females. CONCLUSION: The changes in soft tissue were closely correlated with the hard tissue movement after surgical setback of mandible. The average ratios of soft tissue to hard tissue change in horizontal direction appear to show a gender difference, which suggests the need for different ratios when predicting the results of orthognathic surgery.     

双侧下颌支矢状劈开截骨术后咽腔气道的变化

目的：通过头影测量分析骨性下颌前突患者双侧下颌支矢状劈开截骨术后咽腔气道的变化,为术后保持与防止复发提供依据。方法骨性下颌前突患者20例,均接受口内入路的下颌支矢状劈开截骨术。术前1周、术后1周、术后6个月拍摄标准颅颌侧位片进行头影测量,通过治疗前、后对照,比较下颌支矢状劈开截骨术后咽腔气道的改变。采用SPSS 17.0 软件包对数据进行统计学分析。结果术后1周与术前1周相比,软腭长度显著增加,咽腔气道显著减小;术后6个月咽腔气道有所恢复,与术后1周相比软腭长度显著减小,咽腔气道显著增加;术后6个月与术前1周相比,软腭长度及咽腔气道变化无显著差异。结论骨性下颌前突患者行双侧下颌支矢状劈开截骨术后短期内咽腔气道较术前显著减小,可能加大发生睡眠呼吸暂停综合征的几率。但经过一段时间的组织适应和改建后,咽腔气道有恢复至术前宽度的趋势。     

Relapse after SSRO for mandibular setback movement in relation to the amount of mandibular setback and intraoperative clockwise rotation of the proximal segment

The aim of this study was to evaluate the effect of the amount of setback movement and intraoperative clockwise rotation of the proximal segments on postoperative stability after orthognathic surgery to correct mandibular prognathism.Thirty-six patients with mandibular prognathism who underwent orthognathic surgery with bilateral sagittal split ramus osteotomy were evaluated. The amount of postoperative relapse was analyzed using a cephalometric analysis.Six months after surgery, the mean backward movement of the mandible at point B was 11.2 mm, the mean intraoperative clockwise rotation of the proximal segment was 4.3° and the amount of postoperative relapse at point B was 2.3 mm (20.3%) on average. The tendency of relapse did not significantly increase with the amount of setback but did increase significantly with the intraoperative clockwise rotation of the proximal segment.This study suggested that postoperative relapse after mandibular setback surgery might be more related to the degree of the intraoperative clockwise movement of the proximal segment, rather than the amount of setback movement. When the amount of mandibular setback is considerable, postoperative relapse might be minimized with adequate control of the intraoperative positioning of the proximal segments.     

Factors influencing the predictability of soft tissue profile changes following mandibular setback surgery.

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.     

Mandibular setback by sagittal split ramus osteotomy: a 12-year follow-up

Short- and long-term skeletal changes after mandibular setback were analyzed using bilateral sagittal split ramus osteotomy. Twelve patients who had undergone mandibular setback surgery between 1986 and 1990 were available for long-term cephalography on average 12 years after primary surgery. The mean amount of surgical setback had been 6.4 mm. After the first postoperative year, there was skeletal relapse of 1 mm at the B-point and pogonion (Pg), amounting to 14% of the initial skeletal setback. In contrast to condylar displacement and proximal segment rotation, osteotomy slippage was associated with positional changes at the B-point and Pg. From 1 to 12 years postoperatively, the B-point and Pg remained stable. Mandibular ramus and corpus length decreased 2.1 mm and 1.3 mm, respectively, indicating remodeling at the osteotomy sites and probably condylar resorption.     

Long-term hard and soft tissue relapse rate after genioplasty

PURPOSE: The purpose of this study was to assess hard and soft tissue stability 12 months after advancement genioplasty. MATERIAL AND METHODS: This is a retrospective study of 20 patients who underwent either advancement genioplasty alone (n = 11) or in combination with bilateral sagittal split osteotomy for mandibular advancement (n = 9). Lateral cephalometric radiographs were traced and immediate postoperative changes and 12-month postoperative changes were defined. The relapse rate for the pogonion, the soft tissue pogonion, and the soft tissue B point (Bs) were evaluated. The results were compared for combined mandibular advancement plus genioplasty versus genioplasty alone. Relapse rates were also correlated with the amount of advancement. All patients were treated with rigid internal fixation. RESULTS: After 12 months, the pogonion, the soft tissue pogonion, and the soft tissue B point had a mean relapse rate of -0.38 mm, -1.2 mm, and -1.5 mm (negative value indicates a relapse, and a positive value indicates prolapse), respectively, which was not significant at probability values of.45,.069, and.054, respectively. Relapse was not statistically related to the amount of advancement. There was no significant difference between the relapse rate for genioplasty alone versus combined bilateral sagittal split osteotomy and genioplasty, even with different amounts of advancement. CONCLUSIONS: Advancement genioplasty is an important and reliable technique for the esthetic treatment of the lower facial skeleton. The results indicate that there is no significant relapse after genioplasty and bilateral sagittal split osteotomy or genioplasty alone after 12 months when rigid internal fixation is used. The changes were minimal and hard to detect clinically. Genioplasty, with or without mandibular advancement, is a stable surgical procedure when used in conjunction with rigid internal fixation.     

Stability of skeletal Class II correction with 2 surgical techniques: the sagittal split ramus osteotomy and the total mandibular subapical alveolar osteotomy.

Combined orthodontic and surgical treatment of severe Class II dentoskeletal deformities with the use of the bilateral sagittal split ramus osteotomy is a routine procedure in orthodontic practices. However, an alternative surgical technique, the total mandibular subapical alveolar osteotomy, could be used for the same purpose. The aim of this investigation was to compare the stability of the sagittal split ramus osteotomy with the total mandibular subapical alveolar osteotomy in the correction of dentoskeletal Class II malocclusions. Forty patients that exhibited Class II dentoskeletal relationships were included in the study. Twenty of these patients had mandibular advancement with the sagittal split ramus osteotomy; the remaining 20 patients had advancement of the whole lower alveolar segment with the total mandibular subapical alveolar osteotomy. The cephalograms studied were taken before the surgical procedure (T1 = 4 weeks before operation), immediately after the procedure (T2 = 10 days after surgery), and 1 year later (T3). The statistical analysis used to assess the results between and within the groups over the different time periods was the analysis of variance. The regression analysis was used to test the interdependence of soft tissue response to hard tissue movement. The results of this study show that both procedures are equally stable when correcting Class II malocclusions. This was proved by the stability of the correction of overjet, B point, and incisor-mandibular plane angle. There were no statistically significant differences between or within the groups in the position of these landmarks over time. There was a statistically significant change in the position of pogonion from T1 to T2 (P <.0028) between the groups, although at T3 this difference was not significant (P <.05). There were no significant changes in face height either within or between the groups over time. The hard/soft tissue interactions for the total mandibular subapical alveolar osteotomy were as follows: The lower lip advanced 60% to the incisor movement; soft tissue B' point responded with a 130% advancement in relation to the change in its hard tissue counterpart. Soft tissue pogonion advanced 90% in relation to the hard tissue landmark. The data suggest that the total mandibular alveolar osteotomy is the treatment of choice for the correction of severe dentoalveolar retrusive Class II malocclusion for which alteration of the mentolabial sulcus is desirable.     

Mandibular remodeling after bilateral sagittal split osteotomy for prognathism of the mandible.

PURPOSE: To describe the postoperative remodeling changes in the mandible after bilateral sagittal split osteotomy to correct mandibular prognathism. PATIENTS AND METHODS: Twenty patients who underwent bilateral sagittal split osteotomy for the correction of mandibular prognathism were studied for postoperative remodeling changes within the mandible. The 6-week, 1-year, and long-term postoperative cephalometric mandibular tracings of 12 patients were superimposed using the fixation wires as the stable reference points to demonstrate the specific locations of the intrabony remodeling. RESULTS: There was a general direction of remodeling at the condylion and gonion anteriorly and superiorly, while the B point and pogonion did not show much change in remodeling. At the condylion, 60% and 40% of the cases showed significant horizontal and vertical remodeling, respectively. At the gonion, 50% and 55% of the cases showed significant horizontal and vertical remodeling, respectively. No correlation was found between the remodeling changes at condylion and gonion and the surgical movement or relapse at B point and pogonion. There was a significant correlation between the observed horizontal relapse at gonion and the horizontal remodeling changes at this point showing that the postoperative displacement of this point is a result of both positional translocation and remodeling changes. CONCLUSION: The results of this study show that there are intrabony remodeling changes that occur in the mandible after sagittal split osteotomy and that these continue for a long period of time in some patients. This remodeling occurred more in the condylar and gonial areas, while the chin remained relatively stable.     

A comparison of postoperative,three-dimensional soft tissue changes in patients with skeletal class III malocclusions treated via orthodontics-first and surgery-first approaches

The aim of this retrospective study was to compare three-dimensional (3D) soft tissue and hard tissue changes between orthodontics-first approach (OFA) and surgery-first approach (SFA) after mandibular setback surgery. All patients underwent bilateral sagittal split osteotomy, and were examined by lateral cephalograms and 3D optical scanner before surgery (T0) and 1 (T1), 3 (T2), and 12 (T3) months after surgery. Three standard angles (FMA, U1 to FH, IMPA) were measured as hard tissue change and the 2 sets of 3D data were superimposed, and volumetric differences were calculated as soft tissue change. Statistical analyses were performed by using unpaired t-tests. Differences with P < 0.05 were considered significant. A total of 39 patients with mandibular prognathism were included in this study. The OFA group consisted of 24 patients and the SFA group of 15 patients. The SFA group exhibited more labial inclination from T1 to T2 (p = 0.008) and T2 to T3 (p = 0.003) than did the OFA group. There were no significant changes at maxilla and mandible at each term of T0, T1, T2 and T3 (p > 0.05), but compared to before surgery, mandibular volume in SFA group significant increased at 1year (p = 0.049) after surgery. We found that the soft tissue changes after the SFA differed significantly from those after the OFA; thus, soft tissue predictions require more care. An analysis of our data compared with OFA and SFA for the patient with mandibular prognathism confirm that the mandibular soft tissue changes by postoperative orthodontic treatment and occlusal relationship in SFA.     

Soft tissue profile changes following mandibular advancement and setback surgery an average of 12 years postoperatively.

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.     

How the lower face soft tissue changes after mandibular advancement or setback

To contribute as an auxiliary tool for orthodontic and orthognathic planning and treatment, short-term changes on the lower face soft and hard tissues were investigated. All subjects presented adequate maxillary relation with the cranial base. The treatment was done by mandibular advancement in patients with skeletal class II or setback in skeletal class III, by the same oral surgeon, using the same technique, and rigid internal fixation. Lateral cephalograms were traced at the following intervals: T0--immediately before the surgical procedure, T1--6 months after surgery, and T2--1 year after surgery. The postoperative data of the lower face revealed highly significant changes for the soft tissue pogonion and lower lip, in the mandible advancement cases, whereas the underlying bone and dental structures remained constant. For the mandible setback cases, just the hard tissue pogonion variable displayed a statistically significant change.     

Soft tissue changes after a mandibular osteotomy for symmetric skeletal class III malocclusion

The soft tissue profile is crucial to esthetics after orthognathic surgery. The aim of this study was to assess the soft tissue changes of the subnasal and submental regions more than 1 year after a sagittal split ramus osteotomy (SSRO) in patients with skeletal class III malocclusion. A total of 22 patients with mandibular prognathism were included in this study. Patients had lateral cephalograms before and more than 1 year after they underwent an isolated SSRO. Soft and hard tissue changes were assessed using the lateral cephalograms. The lower lip, labiomenton, and soft tissue menton moved posteriorly by 85, 89, and 88% compared with the corresponding hard tissue, and the movement of the soft tissue B point and the top of the chin nearly reflected the displacement of the hard tissues, at 96 and 99%, respectively. The labiomenton, stomions, and naso-labial angles were changed after the mandibular set-back and the changes in these angles correlated with either the width of the soft tissue or skeletal displacement. The naso-labial angle could be altered even if an isolated mandibular osteotomy is performed. Changes to the stomions and naso-labial angles were affected by hard tissue movement, while changes to the labiomental angle were affected by the width of the soft tissue after the mandibular osteotomy. It is important to create an accurate preoperative prediction of the esthetic outcomes after a mandibular osteotomy by considering the interrelations between the hard and soft tissues.     

Five-year outcome and predictability of soft tissue profiles when wire or rigid fixation is used in mandibular advancement surgery.

The purpose of this study was to follow the covariation of hard and soft tissue changes in Class II malocclusion subjects who received a bilateral sagittal split osteotomy. The subjects were randomized to receive wire or rigid fixation after the surgery. Subjects in the rigid group (n = 78) received 2-mm bicortical position screws, and those in the wire group (n = 49) received inferior border wires and 6 weeks of skeletal intermaxillary fixation with 24-gauge wires. Additionally, some subjects received genioplasty in both the rigid (n = 35) and the wire groups (n = 24). Soft and hard tissue profile changes were obtained from cephalometric films immediately before surgery and at various times up to 5 years postsurgery. Soft and hard tissue profile changes were referenced to a cranial-base X-Y coordinate system. Horizontal changes in mandibular incisor, lower lip, B-point, soft tissue B-point, pogonion, and soft tissue pogonion were calculated at each time. There was considerable skeletal relapse in the wire fixation group. Bivariate correlations and ratios between the hard and soft tissue changes were calculated for each time period. Hard to soft tissue correlations were the highest at the earlier times, although the ratios varied among the 4 groups. These results provide a solid basis for both short-term and long-term prediction.     

Changes in pharyngeal (airway) morphology in Class III Turkish female patients after mandibular setback surgery

INTRODUCTION: The aim of this study was to evaluate changes in the pharyngeal and lower facial morphology in Turkish female Class III patients 1.5+/-0.4 years after mandibular setback surgery (bilateral sagittal split osteotomy), and orthodontic multi-bracket treatment. Only women with mandibular prognathism were selected because sex differences in pharyngeal airway changes were evident. MATERIAL AND METHODS: Lateral cephalograms of 25 Turkish female Class III patients (mean age: 25.4+/-2.6 years) with mandibular prognathism, were assessed before and 1.5+/-0.4 years after operation. Paired t and Pearson tests were used. RESULTS: The pharyngeal airway morphology showed significant changes in soft-palate length and posterior reference line (PRL) to point of posterior tongue. The decrease in PTV-Pg distance was correlated with the decreases in PRL-PSP, PRL-PTO and PRL-E distances. It was considered normal for the pharyngeal airway morphology to adapt after surgery to improve the hard tissue relationship. CONCLUSION: The lower facial morphology significantly changed and the pharyngeal airway narrowed 1.5+/-0.4 years after mandibular setback surgery.     

Three-dimensional computed tomographic evaluation of morphologic airway changes after mandibular setback osteotomy for prognathism

OBJECTIVE: To observe changes in the pharyngeal airway and the hyoid bone position after mandibular setback osteotomy in 30 patients with mandibular prognathism by means of 3-dimensional computed tomography (3DCT). STUDY DESIGN: Preoperative and postoperative computed tomography (CT) examinations were performed on 17 patients treated by sagittal split ramus osteotomy with rigid osteosynthesis and on 13 patients treated by intraoral vertical ramus osteotomy without osteosynthesis. The amount of mandibular setback was measured by the preoperative to postoperative difference of the mandibular position in axial CT images. The sizes of the preoperative and postoperative pharyngeal airway were evaluated from semitransparent and crosscut 3DCT images. Postoperative displacement of the hyoid bone was evaluated by a technique to superimpose a postoperative hard tissue 3DCT image on the preoperative image. The helical scan technique was used in the CT examination. The volume rendering technique was used to create 3DCT images. RESULTS: The mean mandibular setback was 7.8 +/- 2.1 mm with a range of 5 to 11 mm. Three months after surgery, the lateral and frontal widths of the pharyngeal airway had decreased significantly in comparison with the preoperative width. The mean reduction rates of the lateral and frontal width were 23.6% and 11.4%, respectively. The diminished airway did not recover by either 6 months or 1 year after surgery in most cases. Downward and posterior displacement of the hyoid bone was seen postoperatively. There were positive correlations between the amount of mandibular setback and reduction of the lateral width of the pharyngeal airway (r = 0.54) and the amount of hyoid bone displacement (r = 0.42). There were no significant differences between the two surgical techniques. CONCLUSION: Three-dimensional computed tomography was a practical imaging technique to evaluate the morphologic airway changes. The pharyngeal airway may have irreversible narrowing after mandibular setback surgery.     

Soft tissue response to mandibular advancement and genioplasty.

Changes in facial esthetics after orthognathic surgery should be predictable if the results are to be satisfactory. The skeletal elements are moved in a planned and controlled manner, but the soft tissue drape is not as precisely managed. This study was on 31 patients who had undergone a mandibular advancement by means of a sagittal split osteotomy, 17 of whom had also received an advancement genioplasty and 6 received a maxillary impaction. The results showed a consistent 1:1 ratio of soft to hard tissue advancement at pogonion and B point, and that predictions could be accurate in both anteroposterior and vertical directions. When a genioplasty was added to the advancement, however, the results were much less consistent. The mean ratio was 0.9:1 of soft tissue to skeletal movement at pogonion, but the average difference between hard and soft tissue movement was +/- 2.6 mm. Thus the prediction of anteroposterior soft tissue changes was quite inaccurate. Changes in the vertical dimension were also more marked in the genioplasty group. The lower lip also showed a variable response, particularly in the genioplasty group, where the mean ratio was 0.5 mm lip advancement per 1.0 mm skeletal change, but again a range of 4.0 mm in either direction. There were no meaningful changes 1 year after surgery.