Facial soft tissue profile following bimaxillary orthognathic surgery

Occlusal plane rotation and orthodontic decompensation: influence on the outcome of surgical correction of class III malocclusion

PURPOSE

The aim of this retrospective multicenter study is to evaluate the influence of surgical manipulation of the upper occlusal plane (UOP) and orthodontic decompensation on the outcome of class III orthognathic surgery.

METHODS

Incisor inclinations, occlusal plane inclination as well as skeletal and soft tissue changes were assessed in lateral cephalograms of 85 class III patients who had previously undergone orthognathic surgery. Fourteen linear and eight angular measurements were performed on each radiograph at the beginning of treatment (T0), before surgery (T1) and at the end of treatment (T2) using imaging software. After measurement of variables, Mann-Whitney U‑test, repeated-measures analysis of variance (ANOVA) with Bonferroni multiple comparison test, and Spearman's correlation analysis were performed.

RESULTS

A statistically significant improvement was observed in both sagittal skeletal and soft tissue measurements (p < 0.05). Surgical change in UOP was significantly correlated with changes in overbite, upper lip strain and soft tissue B‑point change in the sagittal direction (p < 0.05). Overjet change was significantly correlated with changes in the soft tissue and all sagittal skeletal parameters except for SNA. Changes in the incisor inclinations was significantly correlated with changes in the sagittal skeletal parameters and lower facial height. Significant differences were also observed between the groups with induced clockwise or counterclockwise rotation of the mandible in terms of IMPA (long axis of LI to mandibular plane), overbite, upper lip strain and position of soft tissue B‑point (p < 0.05).

CONCLUSION

Sufficient dental decompensation is crucial for controlling the sagittal as well as the vertical relationship during surgery. Counterclockwise rotation provides an increase in sagittal projection of the mandibular body at the soft tissue B‑point.

Morphological Changes in Total and Inferior Part of Maxillary Sinus After Le Fort I Osteotomy, as Determined by Cone-Beam Computed Tomography

To investigate morphological changes of the total and inferior part of the maxillary sinus following Le Fort I osteotomy. 21 skeletal class II and 49 skeletal III patients who underwent orthognathic surgery were enrolled in this retrospective study. Cone-beam computed tomography taken before (T1) and 6 to 24 months after (T2) orthognathic surgery were imported into Mimics 20.0 software to analyze morphological changes of the total and inferior part of the maxillary sinus. Volume of the whole maxillary sinus was significantly reduced after surgery ( P ≤0.008), while the volume of the inferior part of the maxillary sinus was significantly greater than before surgery ( P ≤0.004). Maxillary sinus floor moved occlusally after Le Fort I osteotomy. Movement in the pitch direction of the posterior maxilla affected the state of the maxillary sinus mucosa after orthognathic surgery. Le Fort I osteotomy exerts a significant impact on the morphology of the total and inferior part of the maxillary sinus.

Effects of modified step Le Fort I advancement surgery on nostril area and inferior nasal structures volume in class III patients: a retrospective clinical study

OBJECTIVE

The effect of the modified step Le Fort I osteotomy on the inferior nasal structures and the nostril area was evaluated.

MATERIALS AND METHODS

This study included 24 patients who had modified step Le Fort I osteotomy. Inferior nasal concha volume (INCV), meatus nasi inferior volume (MNIV), the sum of both structures volume (TV), and nostril area (NA) were evaluated in pre- (T0) and postoperative (T1) periods.

RESULTS

For all patients, NA increased both on the right side (p = 0.011) and left side (p = 0.050) after surgery. The INCV and TV values were lower in T1 than those in T0; however, a statistically significant decrease of INCV and TV was found only in the right side of males (p = 0.039 and p = 0.050, respectively). No significant difference was found in MNIV between T0 and T1 measurements (p > 0.05).

CONCLUSION

Maxillary advancement with the modified step Le Fort I osteotomy technique increased the NA, which may have a positive effect on breathing function. On the other hand, although TV tended to decrease, MNIV did not change after surgery as the same decreasing tendency also existed in INCV.

CLINICAL RELEVANCE

Step Le Fort I advancement surgery technique usually affects nasal structures positively regarding the nasal airway.

Investigation of the Relationship between Sagittal Skeletal Nasal Profile Morphology and Malocclusions: A Lateral Cephalometric Film Study

The aim of this study was to evaluate the relationship between skeletal sagittal nasal profile morphology and sagittal skeletal malocclusions. Regarding lateral cephalometric films, the study was conducted in a total of 135 individuals without any prior orthodontic treatment (mean age of 17.91 ± 1.91), including 49 males (mean age 17.91 ± 1.16) and 86 females (mean age 17.78 ± 1.91 years). The groups were divided into two groups as male and female according to gender, and three groups as skeletal Class 1, Class 2, and Class 3 according to the Steiner's ANB angle. In addition, skeletal groups were compared within groups by dividing into two groups of male and female. A total of eight parameters, three skeletal sagittal angular (SNA, SNB, and ANB angles), four nasal linear (R-A, N-A, N-ANS, and N-R distances) and one nasal angular (N1-N2/N2-R angle), were measured on each cephalometric film. The arithmetic mean and standard deviation of all measured nasal parameters were calculated. For statistical analysis, independent sample t-test and one-way analysis of variance (One-Way ANOVA) were used for normally distributed data, and Mann Whitney U and Kruskal Wallis tests were used for data that did not show normal distribution. For statistical analysis, p < 0.05 was considered significant. R-A, N-A, and N-ANS linear nasal parameters differed significantly between the male and female groups, which were evaluated regardless of the skeletal groups, with a higher rate in males (p < 0.05). N-R linear nasal parameter showed a statistically significant difference between skeletal malocclusion groups, which were evaluated regardless of gender. N-R distance was found to be significantly longer in skeletal Class 3 individuals than in Class 1 and 2 individuals (p < 0.05). There was no statistically significant difference in nasal bone concavity angle in all groups (p > 0.05). R-A and N-A linear nasal parameters showed statistically significant differences between male and female sex groups in all skeletal malocclusion classes (p < 0.05). At first, results showed that males had longer measurements than females in all linear nasal parameters. Second, longer measurements were found in all linear nasal parameters in skeletal Class 3 individuals than those in skeletal Class 1 and Class 2 individuals. Third, the nasal bone concavity angle was greater in skeletal Class 2 individuals than the others.

Effects of maxillary advancement on maxillary incisor display in patients with skeletal Class III malocclusion and cleft lip and palate

INTRODUCTION

The information on the hard- and soft-tissue factors correlated with tooth display after LeFort I osteotomy, especially in the surgery-first approach (SFA), are limited. This study aimed to correlate different parameters with the maxillary incisor display in patients with skeletal Class III malocclusion and those with cleft lip and palate (CLP) in SFA.

METHODS

This study consisted of 35 patients with skeletal Class III malocclusion and 32 with cleft deformities who had undergone orthognathic surgery. Pretreatment and posttreatment lateral cephalometric analysis were obtained. Maxillary incisor display was measured in photographs. The intraclass correlation coefficient was used to assess the intraexaminer repeatability. The Student t test was used to compare the maxillary incisor display between 2 groups. Analysis of covariance was performed with pretreatment measurement as covariates, and the important determinants for maxillary incisor display were identified by adjusting the baseline measurements.

RESULTS

The mean increase of maxillary advancement at point A was 5.25 mm and 1.28 mm downward movement for skeletal Class III malocclusion, whereas it was 4.59 mm advancement and 2.16 mm downward movement for patients with CLP. The resulting maxillary incisor display was 2.86 mm for skeletal Class III malocclusion and 2.56 mm for patients with CLP. The covariates for maxillary incisor display before intervention was significantly associated with the maxillary incisor display after intervention (P <0.001). However, the interaction effect of groups was not seen (P = 0.933). The horizontal position of A, vertical position of ANS, and upper lip length were the most predictable parameters (P <0.001, P <0.001, P = 0.048, respectively) for maxillary incisor display in both groups.

CONCLUSIONS

Horizontal position of point A, vertical position of ANS, and upper lip length are the most important determinants for maxillary incisor display for patients with skeletal Class III malocclusion and those with CLP.

Effect of Orthognathic Surgery on Movement of the Cheilion

The cheilion (Ch), corner of the mouth, is the soft-tissue landmark where the upper and lower lips intersect. Orthognathic surgery can modify Ch position, which can affect facial esthetics. The aims were to evaluate Ch movements resulting from Le Fort I maxillary advancement with maxillary impaction or downgrafting, and with mandibular advancement or setback, and to investigate relationships between surgical movements and Ch movements. The 45 patients had undergone bilateral sagittal split ramus osteotomy with Le Fort I advancement surgery. They were divided into 4 groups according to surgical movement direction. Preoperative and postoperative photographs were calibrated. Standardized methods were used to identify and measure preoperative and postoperative Ch positions. Significant correlations were detected between extent of maxillary downgrafting and inferior movement of the Ch in group 1 (r=0.988, P=0.001) and group 3 (r=0.915, P=0.001). Also, significant correlations were detected between extent of mandibular advancement and anterior movement of the Ch in group 3 (r=0.561, P=0.046) and group 4 (r=0.661, P=0.005). The findings indicate that, in patients who undergo bilateral sagittal split ramus osteotomy/Le Fort I surgeries, mandibular advancement moves Ch anteriorly and maxillary downgrafting moves Ch inferiorly.

Accuracy of 3 Soft Tissue Prediction Methods After Double-Jaw Orthognathic Surgery in Class III Patients

PURPOSE

We aimed to evaluate the accuracy and validity of conventional manual prediction method (CM) and 2-dimensional and 3-dimensional (3D) soft tissue prediction methods for Class III bimaxillary orthognathic surgery patients.

METHODS

Twenty skeletal Class III patients were included in this study. Soft tissue prediction was achieved with a traditional manual technique, 2-dimensional software (Dolphin Imaging, version 11.5), and 3-dimensional software (SimPlant Master, version 16.0) on preoperative lateral cephalometric radiographs and cone beam computurized tomography (CBCT) images and then compared with postoperative lateral cephalometric radiographs obtained at least 6 months after surgery (mean, 11.5 ± 6.77 months). Forty-eight measurements were done to determine the reliability of the methods.

RESULTS

All prediction methods have limited postsurgery prediction accuracy for the subnasal upper lip area. Most of the differences were not more than 3 mm for all study groups, except the 3D software, which predicted the upper lip area to be, on average, 3.08 ± 1.38 mm further back (P < 0.001). Although the conventional method predicted 20 of 48 measurements similar to the final results, the poorest predictions were found at the nasal and labiomental areas (P < 0.001). Two-dimensional software predicted 23 of 48 measurements very close to the final results but made significantly different predictions for the nasolabial and labiomental angles, labrale superius point, and the chin area.

CONCLUSIONS

The 3D method predicted, especially the upper lip area, to be significantly and clinically incorrect, and its soft tissue prediction was insufficient compared with the other 2 methods. The 3D software needs to be updated, especially in evaluating soft tissue A point and upper lip changes after surgery.

Effect of Mandibular Setback Surgery on Tongue Length and Height and Its Correlation with Upper Airway Dimensions

INTRODUCTION

The changes in length and height of tongue following mandibular setback (MS) surgery may affect pharyngeal airway dimensions. There is limited literature correlating tongue dimensional changes with linear and volumetric airway changes following MS with bilateral sagittal split ramus osteotomy (BSSRO) in skeletal class III patients.

MATERIALS AND METHODS

Treatment records of 18 patients who underwent MS with BSSRO were evaluated for changes in tongue and linear airway dimensions, mean airway volume and area at T1 (1-week pre-surgery), T2 (6-month post-surgery) and T3 (2-year post-surgery). Amount of MS was recorded from case sheets of patients. Mean tongue length reduced, whereas mean tongue height increased at T2 compared to T1 (P value = 0.001 for both). Linear, area and volumetric airway parameters at T2 were significantly reduced (P value = 0.001). All parameters showed statistically nonsignificant increase from T2 to T3 (P value > 0.05). Correlation analysis showed that change in tongue length at T3 did not show statistically significant correlation with amount of MS, changes in linear, area and volumetric airway parameters (P value > 0.05). However, the change in tongue height at T3 showed a significant (P value < 0.05) negative correlation (r value = - 0.742) with change in posterior airway space (PAS).

CONCLUSIONS

The appraisal of tongue length and height after MS surgery should be an integral part of diagnosis and treatment planning. The retro-positioning of tongue and increase in its height after MS surgery may compromise pharyngeal airway especially PAS. Additional options such as bi-jaw surgery, debulking of tongue volume and genioplasty should be explored to minimize adverse effects post-surgically.

Correlation between cephalometric nasal changes and patients' perception after orthognathic surgery

INTRODUCTION

The purpose of this study was to evaluate the correlation between cephalometric measurements and patients' perception of nasal changes in those with Class III malocclusion who had undergone orthognathic surgery.

METHODS

Eighty-five patients (36 men and 49 women) who received maxillary advancement with (group 1) or without (group 2) maxillary impaction were included in this study. Lateral cephalometric radiographs taken before and at the end of the treatment were analyzed. The patients were given an esthetic evaluation form and asked to evaluate their own noses on the Likert scale (subjective perception), while at the same time, they were asked to evaluate profile silhouettes without knowing that it was their own profile (objective perception). The changes and correlations between the cephalometric measurements and the scores obtained from the esthetic perception questionnaire were evaluated statistically.

RESULTS

Postoperative nasal tip inclination and rotation, nasofacial angle, and sagittal position of pronasale had increased significantly (P <0.05), whereas nasal tip protrusion, nasofrontal angle, and vertical position of pronasale had decreased (P <0.05). The change in the nasolabial angle and vertical position of pronasale was statistically different between the 2 surgical groups (P <0.05). In the end, a significant increase was observed in the patients' objective nasal esthetic scores (P <0.05).

CONCLUSIONS

Soft tissues are affected by the vertical and sagittal surgical movements of the maxilla. There was a moderate correlation between patients' perception of nasal changes and cephalometric measurements. The subjective evaluation of the nose was similar among patients after surgery, but in the objective assessment, patients found their noses more esthetic.

Orthosurgical Management of a Patient with Cleft Lip and Palate

A 31-year-old male patient reported with a chief complaint of a forwardly placed lower jaw. Oral examination revealed Angle's Class III relationship bilaterally and cephalometrically; the patient presented with a small-sized retrognathic maxilla and normal mandible. Orthosurgical treatment was carried out with 4 mm of maxillary advancement and 4 mm of mandibular setback to achieve ideal overjet, overbite, and intercuspation of teeth. The ANB angle showed a drastic change from −9.5° to 1° and a successful conversion of the skeletal profile from Class III to Class I. Orthosurgical treatment can thus be an effective means of treating a patient with cleft lip and palate but requires a detailed understanding of the case and a sound diagnosis to attain a successful outcome.

Association between Lateral Cephalometric Changes in X-Y Coordinate System and Profile Changes among Skeletal Class III Patients after Orthognathic Surgery

BACKGROUND

Since aesthetic issues are the most important causes of referring skeletal class III patients to surgeons, investigating the impact of orthognathic surgeries on improving patient profiles increases the quality of treatment and quality of life.

METHODS

In a retrospective observational-analytical study, 25 patients older than 18 years with class III skeletal malocclusion who had gone under both orthodontic and double-jaw orthognathic treatment were enrolled. Cephalometric imaging interval was before and at least 6 months after surgery. By defining a number of points and coordinate axes (X-Y), a criterion for comparing hard and soft tissue changes was obtained. These measurements were coordinated, linear and angular. The quantitative data were compared with data obtained using the Likert Scale Questionnaire by means of electronic "Google Forms" that was completed by orthodontists (n=5) and maxillofacial surgeons (n=5) to rank improvement in post-surgical profiles for both cephalometry and photography from poor to pleasant. Spearman Correlation Analysis was conducted between the quantitative and qualitative data.

RESULTS

Vertical changes of point B and horizontal changes of point PNS showed correlation with improvement of patient profile. Changes in N-Pog line (R=-0.4), mandibular plane angle (R=-0.4) and nasolabial angle (NLA) (R=0.38) were significantly correlated with improvement of profiles.

CONCLUSION

In orthognathic double-jaw surgery on patients with skeletal Class III, forward movement of maxilla, upward positioning of mandible (decreasing anterior facial height), decreasing mandibular plane angle and increasing nasolabial angle would result in a better profile.

Orthodontic incisor retraction caused changes in the soft tissue chin area: a retrospective study

BACKGROUND

To investigate the area and morphological changes around the soft tissue chin after orthodontic incisor retraction.

METHODS

Fifty-nine female adults with bimaxillary protrusion requiring extraction of four premolars were included in the study. Cephalograms were taken before (T0) and after (T1) orthodontic treatment. The soft tissue changes, including the area, thickness and morphology were measured. Paired-t tests were performed for statistical comparisons. Pearson correlation analyses and backward multivariate regression analyses were used to identify the relationship between the soft tissue changes and incisor retraction.

RESULTS

Following the incisor retractions (5.35 ± 1.79 mm and 4.42 ± 1.62 mm for the upper and lower, respectively), there was a significant increase in the soft tissue thickness of L1c-LL (0.64 ± 1.67 mm, P = 0.025) and Pog-Pog' (0.44 ± 1.10 mm, P = 0.022), and a significant decrease in the soft tissue thickness of B-B' (1.21 ± 1.34 mm, P <  0.01). Changes in the area of soft tissue chin and lower lip were not statistically significant (P > 0.05). Pearson coefficient between the thickness changes of B-B' and the retraction of lower incisors was - 0.376. The multiple correlations between the soft tissue thickness changes and incisor retractions were Y = 1.02-0.42a + 0.42b for L1c-LL, and Y = 0.17-0.31b for B-B'.

CONCLUSIONS

The orthodontic incisor retraction could cause soft tissue thickness changes (i.e. an increase in L1c-LL and Pog-Pog' and a decrease in B-B') without area changes.

Trends in surgical-orthodontic management of Class III malocclusions in Western Australia

Aim

The aim of this retrospective cohort study was to identify trends in the surgical-orthodontic management of skeletal Class III malocclusions in Western Australia between 1985 and 2016.

Methods

The records of 225 patients (132 females, 93 males) who received combined surgical-orthodontic correction of their Class III malocclusion between 1985 and 2016 were retrospectively assessed. The subjects were divided into three groups according to surgery type: Group (1) maxillary advancement only; Group (2) mandibular setback only; Group (3) two-jaw surgery.

Results

A trend towards two-jaw surgery for Class III correction was observed. Between 1985 and 2016, 123 patients (55%) were treated via two-jaw surgery; 97 patients (43%) were treated via maxillary advancement alone and five patients (2%) were treated via mandibular setback alone. Between 2011 and 2016, 61% were treated via two-jaw surgery; 37% were treated via maxillary advancement surgery; 2% were treated via mandibular setback surgery. Gender affected surgery type: two-jaw surgery (60% female); maxillary advancement (62% female); mandibular setback (17% female). A greater proportion of females received Class III surgical management in comparison with males (59:41).

Conclusion

Two-jaw surgery is the most common procedure for the surgical correction of skeletal Class III malocclusions in Western Australia. Of the single jaw procedures, isolated maxillary advancement surgery is more common than mandibular setback procedures.

Is It Possible to Protract the Maxilla by Surgically Assisted Rapid Maxillary Expansion and Intermaxillary Class III Elastics?

Objective

The purpose of the present study was to evaluate skeletal and soft tissue changes with surgically assisted rapid maxillary expansion (SARME) and intermaxillary Class III elastics.

Methods

A total of 15 patients (mean age: 19.58 years) were included in the study. Each patient underwent SARME with the use of Class III elastics (500 g) applied through miniscrews to stimulate maxillary advancement. Lateral cephalograms and posteroanterior radiographs obtained before treatment (T1), after SARME and elastic use (T2), and after treatment (T3) were analyzed to determine the changes in each phase of treatment. Planimeter was used to evaluate facial soft tissue changes. Wilcoxon signed-rank test was used to evaluate the changes that occur during treatment.

Results

SARME provided permanent and efficient maxillary expansion at both skeletal and dental levels (p<0.01). Maxillary skeletal (ANS-Ver and U1i-Ver; p<0.01) and soft tissue (Pr-Ver, Sn-Ver, and ULA-Ver; p<0.01) variables and superior upper labial area (Area 1; p<0.05) increased due to maxillary dental and skeletal changes. Superior lower labial area (Area 3; p<0.05) decreased as a result of slight increase in facial height and changes in maxillary-mandibular incisor relationship at the end of the treatment.

Conclusion

The results suggest that the improvement in the facial profiles of the patients is related to the significant increase in the bony and dental support of the upper lip region together with the contribution of the superior lower lip area.

Soft Tissue Changes Following Combined Anterior Segmental Bimaxillary Orthognathic Procedures

AIMS & OBJECTIVES

To analyze the soft tissue response in patients treated by combined anterior segmental bimaxillary procedures.

METHODS

A  Prospective, observational and analytical study was carried out for a period of 2 years involving 37 patients with predefined inclusion and exclusion criteria; lateral cephalograms were taken by the same operator on the standardized unit immediately before and 6 months after surgery; hard and soft tissue landmarks were measured in millimeters to both horizontal and vertical reference lines; any differences in distances were recorded as a surgical change; appropriate statistical test was carried; level of significance was p < 0.05.

RESULTS

All patients underwent anterior maxillary osteotomy with 34 anterior mandibular osteotomies, 2 advancement genioplasties and 1 reduction genioplasty. Analysis showed significant angular, horizontal and vertical change. The significant differences in skeletal variables were observed in N-Pg distance, overjet, overbite, U1-NF angle, L1-Mp angle and soft tissue variables like labiomental angle, upper-lower lip protrusion, upper-lower lip length and lower incisor to labrale inferius distance. Nasolabial angle, interlabial gap and upper incisor exposure were extremely significant.

CONCLUSION

Soft tissue response to surgery is perhaps more predictable after 6 months, so this may be a treatment modality of choice in adult bimaxillary/dentoalveolar protrusion patients who need instant esthetic facial results.

Comparison of the Accuracy of Manual and Digital Cephalometric Prediction Methods in Orthognathic Surgical Planning: A Pilot Study

Objective

To compare and evaluate the reliability of manual and digital cephalometric prediction methods in orthognathic surgical planning.

Methods

Ten adults (5 females and 5 males) with skeletal class III malocclusion were included. The mean patient age was 21.97 years. Pre- to postoperative changes were evaluated using paired t-test. Manual surgical predictions made by tracing on acetate paper and digital predictions made using computer software were compared with actual postoperative values using intraclass correlation coefficient and root mean square.

Results

Statistically significant changes were observed in SNA, SNB, ANB, U1i-FH, and Nperp-A following bimaxillary orthognathic surgery (p<0.001). Postoperative changes in Co-A and Nperp-Pg were statistically significant (p<0.05). Comparison of manual and digital surgical predictions with actual postoperative values revealed that overbite and overjet showed the lowest agreements. Manual predictions were less accurate for points that were difficult to distinguish (Co and U6). Skeletal predictions were more accurate than dental predictions.

Conclusion

Parameters with low reproducibility (Co and U6) decrease the reliability of predictions. Dental predictions were inaccurate in both methods due to the effects of intermaxillary elastics, but both methods yielded similar predictions for skeletal parameters. The impact of applying strong elastics for postoperative intermaxillary fixation should be considered when making surgical predictions.

Three dimensional evaluation of soft tissue after orthognathic surgery

Background

To evaluate the nasolabial soft tissue change three-dimensionally after orthognathic surgery, using a structured light scanner.

Methods

Thirty-two malocclusion patients, who underwent orthognathic surgery, were evaluated. CBCT and 3D facial scans were obtained before surgery and 3 months after surgery. The 3D changes in the 26 landmarks, and the relative ratio of the soft tissue movement to the bony movement, were evaluated.

Results

In the Le Fort I advancement patients, the nasal tip moved 17% forward, compared to the maxillary bony movement, but the nasal prominence decreased 15%. The alar width increased 4 mm after the advancement, and the width decreased 4.7 mm after Le Fort I setback. The relative ratio of the soft tissue movement to the bony movement after bilateral sagittal split osteotomy was about 66% at the Li point in the anteroposterior direction, and it was 21% in the Le Fort I advancement and 14% in Le Fort I setback at the Ls point.

Conclusion

Alar cinch suturing may not be sufficient to overcome the effect of the maxilla advancement compressing the nasal complex. Alar width widening was prevented in Le Fort I setback. However, it is uncertain that the alar cinch suturing was solely responsible. The soft tissue around the mandible tends to accompany the bony movement more than the maxillary area. In addition, structured light scanning system proved to be a useful tool to evaluate the nasolabial soft tissue.

Three-dimensional region-based study on the relationship between soft and hard tissue changes after orthognathic surgery in patients with prognathism

Both deep understanding and reliable prediction of postoperative soft tissue changes are crucial for planning orthognathic surgery. Instead of estimating soft tissue responses by measuring individual landmark changes, this study aimed to investigate the relationship (ratio) between soft and hard tissue movements in different facial regions through three-dimensional cone-beam computed tomography (CBCT). Preoperative and postoperative CBCT images were superimposed using the surface registration method on the basis of the cranial base, and 10 facial regions of interest were defined. Region-based volumetric subtractions between the preoperative and postoperative segments were performed. The volumetric differences and surface of each region were used to estimate the average movement. Correlation and regression analyses were performed to examine the relationships between the corresponding soft and hard tissue movements. An overall pattern of facial soft tissue movement was observed in patients with prognathism who underwent orthognathic surgery. The experiment results have shown that mean ratios for the average soft-to-hard tissue movements in the facial regions varied, which may not exactly be similar to the published reports because of the population biocharacteristics and study methods, but the trend is in agreement with the previous studies. Additionally, the prediction capability of the regression model was significantly high, ranging from 0.786 to 0.857, in upper lip, upper vermilion, and chin regions, thus demonstrating that the skin outline changes in these critical regions could be reliably predicted from the underlying bone movements. These results could likely be applied in future soft tissue simulation in orthognathic surgery.

A Comparative Evaluation of Changes in Soft Tissues After Single-Jaw Surgery and Bimaxillary Surgery in Skeletal Class III Patients

Aims and Objectives

The aim of this study was to compare cephalograms for the hard and soft tissue changes observed in skeletal Class III patients of Indian origin who had undergone either single-jaw mandibular setback (BSSO) or bimaxillary surgery (Le Fort I advancement + BSSO setback) and also to derive a correlation between the changes brought about in the soft tissues by the surgical alteration in hard tissue.

Materials and Methods

The study included records comprising 18 treated skeletal Class III patients, who were divided into two groups based on the surgical procedures advocated: Group I: single-jaw procedure comprised of only mandibular set back, Group II: bimaxillary surgery. Presurgical and post-treatment cephalograms were calibrated and traced using Ilexis FACAD AB-2014 Version 3.8.0.0 software and analyzed with COGS hard tissue analysis and soft tissue analysis. All values for the hard tissue and soft tissue measurements were compared with the norms prescribed for the Indian population.

Results

Upper lip changes were evident in both groups but greater significance was observed in bi-jaw group. Single-jaw patients showed positive correlation for hard to soft tissue mandibular position. Bi-jaw surgical cases exhibited positive correlations between changes Wits variable to soft tissue convexity as well as mandibular position.

Conclusion

The soft tissues changes between Class III patients treated by single-jaw surgery and those treated by bimaxillary surgery when compared revealed that significant differences were observed only in relation to certain measurements such as facial convexity, maxillary prognathism, and upper lip protrusion.

Facial profile and frontal changes after bimaxillary surgery in patients with mandibular prognathism

BACKGROUND/PURPOSE

Patients are always concerned about their postoperative appearance before surgery for facial deformity correction. The present study investigated the facial profile and frontal changes following two-jaw surgery.

METHODS

Forty patients who underwent two-jaw surgery were divided by the amount of mandibular setback (group I: ≤8 mm and group II: >8 mm). Cephalometric radiograms (lateral and frontal) were collected and analyzed at three intervals: preoperatively (T1), immediately postoperatively (T2), and final follow-up (T3). The following points were identified: cheek points (C1-C5), pronasale (Prn, tip of the nose), anterior nasal spine (ANS), subnasal (Sn), point A, labrale superius (Ls), incision superius (Is), labrale inferius (Li), incision inferius (Ii), point B, labiomental sulcus (Si), pogonion (Pog), soft tissue pogonion (PogS), ramus point (RP), and gonion (Go). The immediate postoperative changes (T21), final postoperative changes (T32), and final stability (T31) were calculated and analyzed.

RESULTS

In T31, the cheek line showed significant advancements of 2.3 mm (group I) and 1.6 mm (group II). The soft:hard tissue ratios were significantly correlated: Prn:ANS (0.37:1), Prn:A (0.39:1), Sn:A (0.85:1), C3:A (0.82:1), Ls:Is (0.92:1), Li:Ii (0.91:1), Si:B (0.88:1), and PogS:Pog (group I, 0.78:1 and group II, 0.93:1). The intercondylion and intergonial widths of group II (T31) significantly increased 1.8 and 4 mm, respectively. Regarding the postoperative skeletal stability (T32), group I showed significant correlations between amounts of mandibular setback, but group II did not.

CONCLUSION

In the facial profile, the cheek line showed significant advancement postoperatively. The frontal mandibular transverse dimensions were significantly increased.

Soft Tissue Changes Measured With Three-Dimensional Software Provides New Insights for Surgical Predictions

PURPOSE

Although computer-aided craniofacial reconstructions allow for simulation of hard tissue changes, the prediction of the final soft tissue facial changes remains a challenge. The purpose of the present study was to evaluate the 3-dimensional (3D) soft tissue changes in patients undergoing 2-jaw orthognathic surgery.

PATIENTS AND METHODS

For the present retrospective cohort study, 40 consecutive patients (11 men and 29 women; mean age 23.5 ± 4.9 years) who had undergone 2-jaw orthognathic surgery were selected. We obtained the medical and dental records from 3 weeks before surgery and 6 months after surgery. We used image processing software to segment, superimpose, and quantify the hard and soft tissue displacements in 3 dimensions before and after surgery at 15 paired locations. The soft tissue and hard tissue changes were determined through quantification of homologous landmark displacements between the preoperative and postoperative computed tomography data. We measured the 3D soft and hard tissue changes and the anteroposterior, inferosuperior, and transverse components of the changes. We quantified the ratios between the soft and hard tissue changes, tested Pearson's correlation between these changes, and developed a predictive regression equation for the observations at each location.

RESULTS

We found that soft tissue movement followed the hard tissue movement, with a correlation nearly equal to 0.9 (range 0.85 to 0.98), suggesting that in general the soft tissues of the maxillary and mandibular landmarks are affected similarly by the skeletal movements. The anteroposterior component of the soft tissue 3D displacements followed the hard tissue movement with a ratio greater than 0.9 and with high correlation (r > 0.9) in the mandible.

CONCLUSION

The results of the present study provide surgeons with a ratio of hard to soft tissue change and the strength of the correlations, which will allow for more accurate 3D predictions for both midline and lateral structures in bimaxillary orthognathic surgical cases. In addition, predictive equations for various landmarks were developed and can be used in computer-based prediction programs to aid in treatment planning of soft tissue changes.

Oral motor and electromyographic characterization of adults with facial fractures: a comparison between different fracture severities

OBJECTIVES:

To characterize the oral motor system of adults with facial injuries and to compare the oral motor performance/function between two different groups.

METHODS:

An observational, descriptive, cross-sectional study was conducted in 38 patients presenting with facial trauma who were assigned to the Division of Orofacial Myology of a Brazilian School Hospital. Patients were divided into two groups: Group 1 (G1) consisted of 19 patients who were submitted to open reduction of at least one facial fracture, and Group 2 (G2) consisted of 19 individuals who were submitted to closed fracture reduction with maxillomandibular fixation. For comparison purposes, a group of 19 healthy volunteers was recruited. All participants underwent a clinical assessment that included an oral motor evaluation, assessment of the mandibular range of motions, and electromyographic assessment of the masticatory muscles.

RESULTS:

Clinical assessment of the oral motor organs indicated that G1 and G2 presented deficits related to the posture, position, and mobility of the oral motor organs. Patients also presented limited mandibular ranges of movement. Deficits were greater for individuals in G1, especially for maximal incisor opening. Additionally, patients in G1 and G2 presented a similar electromyographic profile of the masticatory muscles (i.e., patients with facial fractures presented lower overall muscle activity and significant asymmetrical activity of the masseter muscle during maximum voluntary teeth clenching).

CONCLUSION:

Patients in G1 and G2 presented similar functional deficits after fracture treatment. The severity of facial fractures did not influence muscle function/performance 4 months after the correction of fractures.

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.

Frontal-view nasolabial soft tissue alterations after bimaxillary orthognathic surgery in Class III patients

INTRODUCTION

The aim of this before-after clinical trial was to evaluate nasolabial soft tissue changes in the frontal plane after bimaxillary surgery.

METHODS

A total of 20 skeletal Class III Iranian patients needing bimaxillary Le Fort I osteotomy plus mandibular setback surgery were enrolled in this trial. Patients underwent 4.02 ± 1.02 mm of maxillary advancement (Le Fort I osteotomy, 4.33 ± 1.21 mm in men, 3.81 ± 0.86 mm in women) and 7.13 ± 1.74 mm of mandibular setback (intraoral vertical ramus osteotomy, 7.71 ± 2.33 mm in men, and 6.74 ± 1.16 mm in women). Data were acquired via 2D frontal photographs. We compared pretreatment baseline (T ₁), preoperative postorthodontic treatment (T ₂), and postoperative (T ₃) anthropometric measurements using repeated-measures ANOVA and Bonferroni tests (α = 0.05).

RESULT

The 20 patients (12 men, 8 women) were aged 21.85 ± 1.75 years. Between T ₁ and T ₂, nasal width, cutaneous upper labial heights increased overall; cutaneous lower labial height decreased (P < 0.05). Between T ₂ and T ₃, nasal width, widths of the philtrum and mouth, cutaneous upper-lip height, vermilion height of the lower lip, lateral upper-lip height increased; the upper-lip vermilion height and cutaneous lower lip height decreased (P < 0.05). The changes ranged between 0.5 and 5 mm.

CONCLUSION

The applied orthognathic surgery procedures might widen the alar base and mouth width. It might increase the lateral upper-lip height, vermilion height of the lower lip, and cutaneous and overall upper-lip heights while reducing upper-lip vermilion height and shortening the overall lower-lip height.

A systematic review of soft-to-hard tissue ratios in orthognathic surgery. Part III: Double jaw surgery procedures

OBJECTIVE

The aim was to determine the soft-to-hard tissue ratios in profile view in bimaxillary orthognathic surgical corrections.

MATERIAL AND METHODS

A systematic review of studies published in different languages was performed by searching the Medline, Embase, Cochrane Library, Lilacs, Scopus, and Science Direct databases up to August 2015. Additional studies were identified by reference analyses. The methodological quality was evaluated using the instrument developed by the Effective Public Health Practice Project and the Level of Evidence using the Level of Evidence scale from the Oxford Centre for Evidence-based Medicine.

RESULTS

The search identified 16 articles; one of which was included from the manual reference search. The analysis of bias revealed weak methodological quality for all the studies included (LOE IV). The studies were retrospective and presented widely varying ratios. In sagittal movements Sn:ANS showed consistency in the evaluations with 60%-90% ratios in five articles. Pn:A presented 66%-90% when V-Y suturing is executed and Ls:U1 ratio was 60%-100% in 6 articles. In vertical direction, poor data are available, considering Sn:A between 54% and 91% in 3 articles and Ls:U1 between 66% and 97% in 3 articles. The Mla-to-point B ratio in sagittal movements was 100% in six articles and Pg-to-sPg demonstrated a relationship between 90% and 100% in 8 articles.

CONCLUSION

Soft-to-hard tissue ratios varied greatly in literature. The results for the mentolabial angle and soft Pogonion changes were apparently more uniform. The low LOE of the studies prevented a more in-depth analysis.

Numbers of Beauty: An Innovative Aesthetic Analysis for Orthognathic Surgery Treatment Planning

The aim of this study was to validate a new aesthetic analysis and establish the sagittal position of the maxilla on an ideal group of reference. We want to demonstrate the usefulness of these findings in the treatment planning of patients undergoing orthognathic surgery. We took a reference group of 81 Italian women participating in a national beauty contest in 2011 on which we performed Arnett's soft tissues cephalometric analysis and our new “Vertical Planning Line” analysis. We used the ideal values to elaborate the surgical treatment planning of a second group of 60 consecutive female patients affected by skeletal class III malocclusion. Finally we compared both pre- and postoperative pictures with the reference values of the ideal group. The ideal group of reference does not perfectly fit in Arnett's proposed norms. From the descriptive statistical comparison of the patients' values before and after orthognathic surgery with the reference values we observed how all parameters considered got closer to the ideal population. We consider our “Vertical Planning Line” a useful help for orthodontist and surgeon in the treatment planning of patients with skeletal malocclusions, in combination with the clinical facial examination and the classical cephalometric analysis of bone structures.

Clinical and radiographic evaluation of maxillary central incisors exposure in patients undergoing maxillary advancement

INTRODUCTION

Patients with dentofacial deformities may undergo orthodontic or orthodontic-surgical treatment. Both modalities can affect esthetics.

OBJECTIVE

This study aims to evaluate clinical and radiographic changes in exposure of maxillary central incisors occurring after orthognathic surgery for maxillary advancement.

METHODS

A total of 17 patients who underwent orthognathic surgery for maxillary advancement between September, 2010 and July, 2011 were selected. Exposure of maxillary central incisors was evaluated clinically and by lateral cephalograms. Measurements were taken one week before and three months after surgery. Data were paired in terms of sex, age, nasolabial angle, height and thickness of the upper lip, the amount of maxillary advancement, clinical exposure and inclination of maxillary central incisor by statistical tests (CI 95%).

RESULTS

After maxillary advancement, incisor clinical exposure had increased even with relaxed lips and under forced smile. Moreover, there was a mean increase of 23.33% revealed by lateral cephalograms. There was an inverse correlation between upper lip thickness and incisors postsurgical exposure revealed by radiographic images (p = 0.002).

CONCLUSIONS

Significant changes in the exposure of maxillary central incisors occur after maxillary advancement, under the influence of some factors, especially lip thickness.

Effect of maxillary advancement on the change in the soft tissues after treatment of patients with class III malocclusion

The aesthetic outcome of treatment has become increasingly important to patients having orthognathic surgery. The aim of this observational cohort study based on clinical records was to evaluate the effect of maxillary advancement on changes to the soft tissues. We studied 53 patients with class III malocclusion (29 women and 24 men, mean (SD) age 28 (11) years). We identified all patients treated between 1 January 2002 and 30 December 2013 who could be monitored postoperatively for 6 months. To study the effect of maxillary advancement on changes to the soft tissue we distinguished between patients who had had less than 6mm, and those with 6mm advancement or more. In those who had had less than 6mm, we found no significant changes in the soft tissue in the region of the nasolabial angle. However, the lip-chin- throat angle (p=0.016), cervical length (p=0.002), lower lip (p=0.007) and upper lip distance (p=0.0001) from the aesthetic line changed significantly. On the other hand, the changes to the soft tissue in the submental and nasolabial regions were significant in patients with 6mm advancement or more, and indicated a clear improvement in the aesthetic outcome of this region. This aesthetic change for the good in the submental and nasolabial regions after maxillary advancement of 6mm or more should be considered when planning treatment, and reduction in the mandibular setback will reduce the risk of development of a double chin.

Prospective assessment of maxillary advancement effects: maxillary incisor exposure, and upper lip and nasal changes

INTRODUCTION

Our aim was to assess changes in maxillary incisor exposure, and upper lip and nasal soft tissues with maxillary advancement with or without impaction, accounting for the use of cinch sutures and VY closures.

METHODS

This was a prospective study of 41 consecutive patients undergoing maxillary advancement with or without impaction. Lateral cephalometric radiographs and clinical measurements were taken preoperatively and up to 6 months postoperatively by 1 examiner.

RESULTS

Thirty-one patients (19 female, 12 male) with a mean age of 25.5 years (range, 16.9-49.9 years) completed the study. Twenty-six received bimaxillary surgery. Fifteen had simple closures, 6 had cinch sutures, and 10 had alar base cinch and VY closures. The mean amounts of maxillary advancement and impaction were 3.34 and 1.6 mm, respectively. Soft tissues followed increasingly more closely the hard tissue advancement from pronasale to stomion superius. Mean maxillary incisor exposure increased at rest (0.5 mm) and on smiling (1.0 mm). The nasolabial angle increased (1.88°) because of columella upturning. Alar base width (3.09 mm) significantly increased.

CONCLUSIONS

Soft to hard tissue horizontal ratios increased progressively from pronasale to stomion superius. Alar base cinch and VY closures increased these further. Maxillary incisor display changes were partly explained by presurgical upper lip thickness and soft tissue manipulation. Nasolabial angle increased, and cinch sutures seemed to increase this further. Alar base width increased significantly, and the cinch sutures did not significantly limit this.

Nasal profile changes with le fort I maxillary advancement surgery

Introduction : The purpose of this study was to quantify anteroposterior facial soft tissue changes with respect to underlying skeletal movements after Le Fort I maxillary advancement surgery by using lateral cephalograms taken before and after the operation. Materials and Methods : The study group consisted of 20 patients (10 women, 10 men; mean age 23.4 ± 1.4 years) having a Class III skeletal deformity caused by a retrognathic maxilla. All patients were treated by Le Fort I maxillary advancement osteotomy. Lateral cephalograms were taken before and 1.6 ± 0.4 years after surgery. Results : The anteroposterior position of A-point and anteroposterior position of maxillary incisor were significantly protracted (-2.69 ± 3.34 and -2.68 ± 3.21, respectively; P < .01). The nasal anteroposterior and superoinferior positions (NASALAP and NASALSI, respectively) were significantly changed (-2.70 ± 6.81, P < .01, and -2.55 ± 5.80, P < .05, respectively) and nasal elevation and protraction were observed after Le Fort I maxillary advancement surgery. Conclusions : The changes in anteroposterior and superoinferior positions of A-point were correlated with the nasal superoinferior position (r = -0.71 , P < .05; r = 0.72, P < .05) after Le Fort I maxillary advancement surgery.

Soft tissue response after Class III bimaxillary surgery

OBJECTIVE

To analyze the impact of surgical change in anterior face height and skeletal relapse on the long-term soft tissue profile.

MATERIALS AND METHODS

Cephalometric radiographs of 81 patients taken before surgery and at five time points during a 3-year follow-up period were analyzed. All patients had Le Fort I and bilateral sagittal split osteotomies. The patients were divided into three subgroups according to the change in anterior face height during surgery. Calculations of soft to hard tissue ratios were based on the long-term soft tissue response relative to the surgical repositioning.

RESULTS

The horizontal surgical repositioning varied considerably, depending on whether anterior face height was increased or decreased. For upper lip prominence, the pattern of long-term change was the same irrespective of change in face height. In all groups, upper lip thickness decreased in both the short term and the long term, particularly in patients with surgical increase in face height. Lower lip thickness increased in the short term but decreased during the follow-up period. There were significant associations between horizontal soft tissue and corresponding hard tissue changes, except for soft tissue A-point and upper lip, when face height was increased. The ratios were higher for mandibular variables than for maxillary variables, particularly for B-point and pogonion when anterior face height had decreased.

CONCLUSION

A change in facial height influences the soft tissue response. The mandibular soft tissues closely follow skeletal relapse beyond 2 months postsurgery. The findings have clinical implications for the relative maxillary and mandibular repositioning when planning surgery.

Bimaxillary surgery in Class III malocclusion: soft and hard tissue changes

The aim of this study was to quantify anteroposterior facial soft tissue changes with respect to underlying skeletal movements after Le Fort I maxillary advancement and mandibular setback surgery with sagittal split osteotomy in Class III skeletal deformity by using lateral cephalograms taken before and after the operation. The material consisted of 31 patient (15 female, 16 male cases, mean age was 26.7 ± 2.5 years) with Class III skeletal deformity. All patients were treated by Le Fort I maxillary advancement and mandibular setback surgery with sagittal split osteotomy. Lateral cephalograms were taken before and 1.4 ± 0.3 years after surgery. Wilcoxon test was used to compare the pre- and post-surgical measurements. Pearson correlation test was used to compare the relationships between the skeletal, dental and facial soft tissue changes. In the maxilla, the APOINTAP (the anteroposterior position of A point) and ITIPAP (the anteroposterior position of upper incisor) showed significant protractions (-3.19 ± 3.63, and -3.19 ± 4.52, p < 0.01). In the mandible, the L1TIPAP (the anteroposterior position of lower incisor, -3.20 ± 5.83, p < 0.01), L1TIPSI (the superoinferior position of lower incisor, -2.43 ± 10.31, p < 0.05), BPOINTSP (the superoinferior position of B point, -2.28 ± 12.51, p < 0.05) and BPOINTAP (the anteroposterior position of B point, -3.19 ± 9.31, p < 0.01) showed significant retractions and upper positions after bimaxillary surgery. The insignificant decrease in soft tissue Pog-Vert distance was correlated the significant upper position of B point and lower incisor (r: 0.851, p < 0.001 and r: 0.842, p < 0.001).

Facial soft tissue changes after maxillary impaction and mandibular advancement in high angle class II cases

The aim of this study was to determine the vertical and anteroposterior alterations in the soft, the dental and the skeletal tissues associated with the facial profile after Le Fort I maxillary impaction in conjunction with sagittal split osteotomy for mandibular advancement performed in patients with a high angle Class II skeletal deformity.The study population consists of 21 patients (11 females and 10 males, mean age 24.5±1.6 years) who underwent Le Fort I maxillary impaction in conjunction with sagittal split osteotomy for mandibular advancement. Lateral cephalograms were obtained prior to the surgery and 1.3±0.2 years postoperatively. Wilcoxon test was performed to compare the pre- and postsurgical cephalometric measurements. Pearson correlation test was carried out to determine the relative changes in skeletal, dental and the facial soft tissues.The insignificant decrease in the nasolabial angle was correlated with the significant decrease in the vertical position of the nose due to the nasal protraction noticed after bimaxillary surgery. The retraction of both the upper lip and the upper incisors was correlated with the insignificant decrease in the columella-lobular angle. The insignificant decrease in both the vertical height of the mandibular B point and the lower incisors was correlated with the insignificant decrease in vertical height of the soft tissue pogonion, attributable to the resulting superior movement of the soft tissues of the chin and the counter clockwise rotation of the mandible after maxillary impaction and bilateral sagittal split osteotomy, respectively.Le Fort I maxillary impaction in conjunction with mandibular sagittal split osteotomy for mandibular advancement significantly affected the vertical and anteroposterior positions of the maxilla and the mandible, respectively. When performed in combination, these surgical techniques may efficiently alter the position of upper incisor and the nasal position in both vertical and anteroposterior directions. Bimaxillary orthognathic surgery seems to be an efficient method for obtaining satisfactory results in the appearance of the soft, the dental and the skeletal tissues associated with the facial profile in patients with high angle Class II skeletal deformity.

Evaluation of the nose profile after maxillary advancement with impaction surgeries

OBJECTIVE

The aim of this study was to identify and quantify nasal profile changes following maxillary advancement (MA) and maxillary advancement with impaction (MAI) with Le Fort I osteotomies.

METHODS

The study consisted of preoperative and postoperative lateral cephalograms of 42 class III adult patients. The study sample was divided into 2 groups, with the first group composed of 22 patients who underwent MA surgery and the second group composed of 20 patients who underwent MAI surgery. In total, 7 skeletal parameters and 17 soft-tissue parameters related to nasal projection, hump, dorsal convexity, and the nasolabial region were evaluated on the cephalograms, and hard- and soft-tissue relationships were assessed.

RESULTS

Nasal length, hump, nasal depths, distance from the most convex point of the Alar curvature to the most inferior point of the nostril, alar curvature-subnasale, and subnasale-pronasale measurements decreased postoperatively. In the MAI group, MA correlated with significant decreases in nasal length and hump. In the MA group, MA correlated with pronasale position (P < 0.05); significant decreases in nasal depth, columella convexity, and subnasale-pronasale length; and significant changes in subnasale position.

CONCLUSIONS

There is little difference in the effects of the 2 different maxillary surgeries on the postoperative nasal profile.

Importance of the vertical incisor relationship in the prediction of the soft tissue profile after Class III bimaxillary surgery

OBJECTIVE

To quantify the relative soft tissue profile response to the skeletal changes resulting from bimaxillary surgery to correct Class III malocclusion in patients with different vertical incisor relationships presurgery.

MATERIALS AND METHODS

The sample comprised lateral cephalograms of 80 consecutive patients before and 2 months after surgery. All patients had one-piece Le Fort I and bilateral sagittal split osteotomies. Patients were divided in three subgroups according to their preoperative characteristics, as follows: (1) open-bite patients, (2) patients with positive overbite and the upper lip resting on upper incisors, and (3) patients with positive overbite and the upper lip resting on lower incisors (lip-block). Trimmed means of soft to hard tissue ratios were calculated for the subgroups. Regression analyses were performed to examine factors influencing the soft tissue changes.

RESULTS

There were strong correlations between the horizontal movement of upper incisors and upper lip in patients with open bite (r  =  0.77) and in patients with positive overbite and upper lip resting on upper incisors (r  =  0.85). The upper lip followed the maxilla with a ratio of 0.5∶1. In patients with lip-block, the association between maxillary repositioning and upper lip changes was weak. In all groups a strong association between horizontal soft and hard tissue changes was observed for the lower lip and chin, but the pattern differed depending on the vertical movement of the mandible.

CONCLUSIONS

In the prediction of soft tissue response it is important to take into account the vertical incisor relationship, particularly in patients with lip-block.

Short-term periodontal and microbiological changes following orthognathic surgery

OBJECTIVE

Aim of the present study was to evaluate the influence of orthognathic surgery on the development of periodontal and microbiological changes.

MATERIALS AND METHODS

Fifteen consecutively treated patients with a mean age of 24.9±7.7 years receiving orthognathic surgery were included in the present study. Plaque index (PI) and concentrations of 11 periodonto-pathogenic bacteria were recorded one day prior to surgery (t(0)) and one week (t(1)) and six weeks (t(2)) post-surgery. In addition, a complete periodontal examination including pocket probing depth (PPD), gingival recession (GR), clinical attachment level (CAL), bleeding on probing (BOP) and width of keratinized gingiva (WKG) was conducted at t(0) and t(2). For statistical analysis, general linear model and paired t-test were applied.

RESULTS

A significant increase of PI (t(0)-t(1), p=0.037) was followed by a significant decrease (t(1)-t(2), p=0.017). Apart from Eikenella corrodens (p=0.036), no significant microbiological changes were recorded. PPD significantly increased on oral sites (p=0.045) and GR especially on buccal sites (p=0.001). In the incision area the development of GR was significantly higher on the test (buccal) than on the control sites (oral). Both gingival biotypes were affected by GR.

CONCLUSIONS

Orthognathic surgery causes statistically significant changes of periodontal parameters, but these changes do not necessarily impair the aesthetic appearance of the gingival margin.

Retrospective analysis of nasal soft tissue profile changes with maxillary surgery

PURPOSE

The aim of this study was to analyze the changes in the position of the nasal and labial soft tissue profile of patients undergoing bimaxillary orthognathic surgery, with special emphasis on the effect on the nasal tip projection.

MATERIALS AND METHODS

The lateral cephalometric radiographs of 27 consecutive patients (16 female and 11 male patients; mean age, 22 years) who had undergone maxillary advancement and mandibular setback were studied. The pretreatment and end-of-treatment lateral cephalometric radiographs were selected. The pretreatment and end-of-treatment radiographs were superimposed on the sella-nasion plane, and the case was only included if there had been no change in sella-nasion length (ie, no growth). Analyses of Pearson correlation coefficient and stepwise linear regression tests were used to compare the cephalometric measurements at the beginning and at the end of treatment. Paired-sample t tests were also performed to analyze changes in nasolabial angle (NLA) and columella-lobular angle (CLA).

RESULTS

The correlations between vertical movement of nasal tip, A-point, and maxillary incisal tip were important. Although there was an important correlation between nasal and incisal tip, interestingly, there was no correlation between nasal tip and A-point in horizontal movement. According to stepwise linear regression analysis, the best model for horizontal movement of nasal tip was as follows: Nasal anteroposterior movement = 0.241 + 0.188 × Incisal tip anteroposterior movement + 0.153 × Incisal tip superoinferior movement. For vertical movement of nasal tip, the best model was as follows: Nasal superoinferior movement= -1.117 + 0.399 × Incisal tip superoinferior movement + 0.323 × A-point anteroposterior movement. There was no significant relation in angular measurements of NLA and CLA before and after treatment.

CONCLUSION

The results of our study suggest that both horizontal and vertical movements of nasal tip were related to incisal tip and A-point movements; however, angular changes in CLA and NLA did not affect the nasal tip.

Imaging of facial soft tissues in multislice computerized tomography: a new geometric method of analysis and its statistical validation

OBJECTIVE

The main purpose of this preliminary study was to propose an original analysis of facial soft tissues' depth to detect their topographic variability, which causes are intrinsic (depth) and extrinsic (bone shape and reciprocal correlations with soft tissues themselves). To check the utility and accuracy of the method in recognizing measures' differences, other aims were comparison of two different groups of people and statistical validation.

STUDY DESIGN

The study sample was composed of 100 consecutive patients (56 females and 44 males) undergoing a routine CT scanning. The images, obtained through the reference plane of the palate, were post-processed on a PC workstation. A goniometer construction was superimposed and centered on the posterior nasal spine, where a grid of eighteen rays was developed to calculate the superficial soft tissues' depths of the face. To test the validity of the method, three of the rays were measured twice, by the same as by another observer. Step-by-step procedures were attained to get maximum standard in measures' reliability.

RESULTS

Superficial soft tissues' depths were obtained and sex differences were analyzed (Student's t and Wilcoxon rank-sum test). The statistical reliability was proven with Bland-Altman statistics and the upper 95% limit of agreement was 1.459 mm for intraobserver repeatability and 1.886 mm for interobserver reproducibility. Validation of the method was proven by intraclass correlation coefficient (0.99 both for repeatability and reproducibility) and mean differences (respectively 0.6% and 0.4%).

CONCLUSION

The method appeared easy to be applied, reliable and not observer dependent, so suitable for study single as multiple patients with CT images. Future analyses shall be possible.

Professionals' and laypersons' appreciation of various options for Class III surgical correction

SUMMARY

The objectives of this study were to evaluate the assessments of maxillofacial surgeons, orthodontists, and laypersons on the predicted aesthetic outcome of various surgical options in Class III correction and the associations between certain initial cephalometric values and the judges' preferred option. Pre-surgical lateral headfilms and coloured profile photographs of 18 skeletal Class III Caucasian adult patients (10 males and 8 females) with a mean age of 24.5 years were used. The headfilms were hand traced and digitized. Conventional cephalometric analysis was performed. Computerized predictions of three surgical options, mandibular setback, Le Fort I advancement, and bimaxillary surgery, were made. For each case, the pre-surgical profile photograph with the three predictions was presented on a printed page. The questionnaire was sent to 51 maxillofacial surgeons (response rate 45.1 per cent), 78 orthodontists (response rate 71.8 per cent), and 61 laypersons (response rate 100 per cent) to aesthetically evaluate the pre-surgical photographs and the surgical predictions by placing a mark along a 10-graded visual analogue scale (VAS) using a standard profile for calibration. Confidence interval was calculated for each patient. An independent samples t-test was used to detect initial cephalometric values associated with the judges' preferred option and analysis of variance/Tukey's honestly significant differences to evaluate differences between judges. Intra-observer reliability was assessed with a paired t-test. All treatment predictions led to improved scoring of facial aesthetics with the exception of the setback option for three patients. For 14 patients, general agreement for the preferred option existed between the three groups of judges. Laypersons tended to give lower improvement scores than professionals. Overjet, nasofacial, and nasomental angles were important in decision making between the mandibular setback and Le Fort I options (the more negative the overjet, the larger the nasofacial angle, the smaller the nasomental angle, the greater the preference for the Le Fort I option). Wits appraisal seemed to be important in decision making between the mandibular setback and bimaxillary options (the more negative the Wits appraisal, the greater the preference for the latter option).