Profile changes in orthodontic patients treated with mandibular advancement surgery

Perceived Effects of Orthognathic Surgery versus Orthodontic Camouflage Treatment of Convex Facial Profile Patients

Increased facial profile convexity has a common occurrence in the population and is a primary reason for seeking orthodontic treatment. The present study aimed to compare the perceived changes in facial profile appearance between patients treated with combined orthognathic/orthodontic treatment versus only orthodontic camouflage treatment. For this reason, 18 pairs of before- and after-treatment facial profile photos per treatment group (n = 36 patients) were presented to four types of assessors (surgeons, orthodontists, patients, laypeople). Ratings were recorded on 100 mm visual analogue scales depicted in previously validated questionnaires. All rater groups identified minor positive changes in the facial profile appearance after exclusively orthodontic treatment, in contrast to substantial positive changes (14% to 18%) following combined orthodontic and orthognathic surgery. The differences between the two treatment approaches were slightly larger in the lower face and the chin than in the lips. The combined orthodontic and orthognathic surgery interventions were efficient in improving the facial appearance of patients with convex profile, whereas orthodontic treatment alone was not. Given the significant influence of facial aesthetics on various life aspects and its pivotal role in treatment demand and patient satisfaction, healthcare providers should take these findings into account when consulting adult patients with a convex facial profile.

Three-dimensional assessment of periodontal support of lower incisors for skeletal Class II malocclusion undergoing presurgical orthodontic treatment with different vertical skeletal patterns

BACKGROUND

The aim of the present study was to compare periodontal support changes during retraction of mandibular anterior teeth for skeletal Class II malocclusion with different facial divergence and to analyze relevant factors influencing bone remodeling by applying three-dimensional (3D) cone-beam computed tomography (CBCT) reconstruction technology.

METHODS

Forty-eight patients with Class II malocclusion requiring surgical orthodontic treatment enrolled in the study were divided into the hyperdivergent group (n = 16), normodivergent group (n = 16) and hypodivergent group (n = 16) according to their vertical skeletal patterns. Cone-beam computed tomography (CBCT) scans were obtained before treatment (T1) and after presurgical orthodontic treatment (T2). The two-dimensional (2D) alveolar bone morphology, movement of mandibular central incisors and volume of the alveolar bone around incisors were measured on the labial and lingual sides by 3D CBCT reconstruction technology. Statistical analyses were performed with one-way ANOVA, paired t tests and multiple linear regression.

RESULTS

During presurgical orthodontic treatment, the alveolar bone height on the labial side of the hyperdivergent group decreased significantly (P ≤ 0.05), but was maintained in the normodivergent and hypodivergent groups (P > 0.05). However, the alveolar bone volume, alveolar bone thickness at each level and alveolar bone height on the lingual side decreased significantly for all the groups. Apart from the initial morphometric measurements at T1, the morphology of lingual alveolar bone at T2 was significantly influenced by the direction and amount of tooth movement. Horizontal retraction and vertical protrusion of the root apex were negatively related to the alveolar bone on the lingual side after presurgical orthodontic treatment.

CONCLUSION

For Class II malocclusion patients undergoing presurgical orthodontic treatment, the changes in the periodontal support of the lower central incisors varied in different vertical skeletal patterns. There exists a great periodontal risk of alveolar bone resorption on the lingual side for various vertical types. To avoid alveolar bone deterioration, it is essential to investigate the bone remodeling of patients with different alveolar bone conditions and cautiously plan tooth movement prior to orthodontic treatment. Moreover, 3D measurements based on CBCT construction can provide complementary information to traditional 2D measurements.

Comparing the esthetic impact of virtual mandibular advancement, bichectomy, jawline, and their combination

INTRODUCTION

The purpose of this study was to compare the effects of mandibular advancement (MA), bichectomy, jawline, and their combination on facial attractiveness. The 3-dimensional (3D) visual sculpting is a method to perform the task.

METHODS

FaceBuilder software, a Blender 2.93 LTS add-on, was used to generate a 3D head and face model of a female patient with Class II Division I malocclusion. MA, bichectomy, jawline, and combination modifications were performed on the model using a 3D virtual sculpting tab, and 4 new head models were created. Five hundred thirteen participants scored lateral and frontal views of the modified and reference models. The Mann-Whitney U, Kruskal-Wallis, and Wilcoxon tests were used for statistical analysis.

RESULTS

MA modification received the highest frontal and lateral image scores. The raters found the jawline frontal photograph to be the least attractive. Significant differences were observed between the lateral and frontal attractiveness scores in all modifications except bichectomy. The combination of 3 modifications in both frontal and lateral images received the second-lowest score.

CONCLUSIONS

Facial esthetic modifications receive different attractiveness scores in lateral or frontal evaluations. MA outperforms bichectomy and jawline augmentation in terms of improving facial attractiveness.

The effect of orthodontic treatment on facial attractiveness: a systematic review and meta-analysis

BACKGROUND

Facial and smile attractiveness are significant motivating factor for patients to seek orthodontic treatment. Although there is a general belief that orthodontic treatment improves facial appearance, this has yet not been systematically evaluated.

OBJECTIVE

The objective of this study was to assess the current evidence on the effect of orthodontic treatment on facial attractiveness.

SEARCH METHODS

Systematic and unrestricted search of nine databases were performed up to January 2022.

SELECTION CRITERIA

Studies evaluating facial attractiveness before and after orthodontic treatment.

DATA COLLECTION AND ANALYSIS

Extracted data included study design and setting, sample size and demographics, malocclusion type, treatment modality, and method for outcome assessment. Risk of bias was assessed with the ROBINS-I tool for non-randomized studies and with RoB-2 for randomized controlled trials (RCTs). Random-effects meta-analyses of mean differences and their 95% confidence intervals (CIs) were performed.

RESULTS

Twenty studies were included in data synthesis; three randomized controlled clinical trials and 17 non-randomized clinical studies of retrospective or prospective design. One of the RCTs was found to have low risk of bias, one presented some concerns and the third showed a high risk of bias. All non-randomized studies showed either unclear or high risk of bias. Data syntheses showed that orthodontic treatment improved facial attractiveness ratings by 9% when compared with untreated controls (MD: 9.05/95% CI: 4.71; 13.39). A combination of orthodontics and orthognathic surgery also showed a positive effect of 5.5% (MD: 5.51/95% CI: 1.55; 9.47) when compared with orthodontic treatment alone. There was no difference in effect between extraction and non-extraction treatments (MD: -0.89/ 95% CI: -8.72; 6.94) or between different types of Class II correctors (MD: 2.21/95% CI: -16.51; 20.93).

LIMITATIONS

With the exception of two RCTs, included studies were of unclear or low quality.

CONCLUSIONS

Orthodontic treatment has a clinically weak effect on facial attractiveness when compared to no treatment. The same is true when a combined orthodontic/surgical treatment is compared to orthodontics alone.

REGISTRATION

PROSPERO #: CRD42020169904.

Effect of lower facial height and anteroposterior lip position on esthetic preference for Korean silhouette profiles

OBJECTIVE

The purpose of this study was to evaluate the esthetic preference for various Korean silhouette profiles.

METHODS

The Korean average male and female profiles were modified by changing the lower facial height and anteroposterior lip position to produce nine types of profiles. In order to test intrarater reliability, the average profile was copied once more to be included for evaluation. A questionnaire containing 10 profiles for each sex, each of which had to be rated for preference on a numerical rating scale from 0 to 10, was administered to 30 adult orthodontic patients, 30 dental students, 30 orthodontists, and 30 dentists excluding orthodontists. The data were statistically analyzed using the intraclass correlation coefficient (ICC), independent t-test, and one-way ANOVA.

RESULTS

The ICC of overall intrarater reliability was 0.629. For several profiles, significantly higher scores were given to male profiles than to female profiles (p < 0.05). However, no significant differences were found in the scores for all profiles among the four rater groups. Among the short profiles, a significantly higher score was given to the retruded profile, and among the vertically average and long profiles, a significantly higher score was given to the horizontally average profile (p < 0.001). Among all the profiles, significantly lower scores were given to the protruded profile (p < 0.001).

CONCLUSIONS

This study revealed good overall intrarater reliability, with several types of male profiles being esthetically preferred over female profiles. Moreover, while retruded and horizontally average profiles were generally preferred, protruded profiles were not.

Evaluation of Facial Profile Esthetics After Maxillomandibular Advancement Surgery for the Treatment of Obstructive Sleep Apnea

PURPOSE

Maxillomandibuar advancement (MMA) surgery has been shown to be a successful treatment for obstructive sleep apnea (OSA), but concerns still exist regarding esthetic outcomes due to the large advancements involved. The objective of this study was to evaluate facial profile changes in patients who underwent MMA surgery for OSA by utilizing panels of external evaluators.

METHODS

Pre- and posttreatment silhouettes of 21 patients (10 females, 11 males; mean age 43.2 [±11.5] years), who underwent MMA surgery for OSA, were generated from profile photographs. Utilizing survey software, the individual silhouettes were shown in random order to surgeons, orthodontists and laypeople, who assessed the esthetics of each via a sliding visual analogue scale (0 to 10).

RESULTS

For all evaluators combined, postsurgical esthetic scores were significantly improved in 19 of 21 patients (P < .001). Ninety-five percent of evaluators judged the changes after surgery as positive or neutral. There was a mean increase in postsurgical esthetic scores of 1.9 [±1.9], which was moderately correlated with AHI changes (r = 0.48, P < .05). Mean esthetic score changes were significantly different between evaluator groups for 12 of 21 patients (P < .05), with surgeons and orthodontists reporting more positive change than laypeople.

CONCLUSIONS

Overall, MMA surgery for the treatment of OSA does not have a negative impact on facial profile esthetics, with external evaluators judging the changes as favorable in the majority of patients assessed.

Development of novel artificial intelligence systems to predict facial morphology after orthognathic surgery and orthodontic treatment in Japanese patients

From a socio-psychological standpoint, improving the morphology of the facial soft-tissues is regarded as an important therapeutic goal in modern orthodontic treatment. Currently, many of the algorithms used in commercially available software programs that are said to provide the function of performing profile prediction are based on the false assumption that the amount of movement of hard-tissue and soft-tissue has a proportional relationship. The specification of the proportionality constant value depends on the operator, and there is little evidence to support the validity of the prediction result. Thus, the present study attempted to develop artificial intelligence (AI) systems that predict the three-dimensional (3-D) facial morphology after orthognathic surgery and orthodontic treatment based on the results of previous treatment. This was a retrospective study in a secondary adult care setting. A total of 137 patients who underwent orthognathic surgery (n = 72) and orthodontic treatment with four premolar extraction (n = 65) were enrolled. Lateral cephalograms and 3-D facial images were obtained before and after treatment. We have developed two AI systems to predict facial morphology after orthognathic surgery (System S) and orthodontic treatment (System E) using landmark-based geometric morphometric methods together with deep learning methods; where cephalometric changes during treatment and the coordinate values of the faces before treatment were employed as predictive variables. Eleven-fold cross-validation showed that the average system errors were 0.94 mm and 0.69 mm for systems S and E, respectively. The total success rates, when success was defined by a system error of < 1 mm, were 54% and 98% for systems S and E, respectively. The total success rates when success was defined by a system error of < 2 mm were both 100%. AI systems to predict facial morphology after treatment were therefore confirmed to be clinically acceptable.

Comparison of Profile Attractiveness between Class III Orthodontic Camouflage and Predictive Tracing of Orthognathic Surgery

Objective

The aim of this study was to compare the profile attractiveness between orthodontic camouflage of the Class III malocclusion and the predictive tracing simulating orthognathic surgery evaluated by dentists and laypeople. Settings and sample population. The sample consisted of 21 patients (9 male; 12 female) with Class III malocclusion treated with orthodontic camouflage and Class III intermaxillary elastics. Material and Methods. The mean initial age of the patients was 24.38 years (SD 3.32), and the mean ANB angle was −1.91° (SD 0.83°). Patients presented skeletal Class III and normal growth patterns. Initial and final lateral cephalograms of each patient were used. The initial cephalogram was used to perform the treatment simulation of orthognathic surgery, and its silhouette was compared to the silhouette obtained from the final cephalogram after Class III orthodontic camouflage. A subjective analysis of profile attractiveness was performed by 47 laypeople and 60 dentists, with scores from 1 (less attractive) to 10 (most attractive). Mann–Whitney tests were used to compare profile attractiveness between the orthodontic treatment and the predictive tracing groups and between dentists and laypeople.

Results

The predictive tracing of orthognathic surgery showed to be statistically significantly more attractive (mean score 4.57, SD 2.47) than that of the Class III camouflage orthodontic treatment (mean score 4.22, SD 2.40), with a mean numerical but significant difference of 0.35 (SD 2.01) (P < 0.001). Laypeople were more critical than dentists in evaluating profile attractiveness, but numerical difference between the groups was also small.

Conclusion

The profile silhouette of predictive tracing simulating orthognathic surgery showed to be more attractive than that of Class III camouflage orthodontic treatment; however, differences were small but statistically significant. Laypeople showed to be more critical than dentists.

Orthodontic-surgical treatment for a patient with Class II malocclusion and inadequate maxillary incisor inclination

Dental health and patient satisfaction at the end of orthodontic treatment are needed if the treatment is to be considered successful. This case report highlights the importance of proper diagnosis for a patient initially treated with camouflage, despite the indications for surgery. A 16-year-old male patient sought treatment complaining about his appearance. He had been using an appliance for 6 years without improvement. He had a convex profile, an enlarged lower third of the face, reduced cervical-mandibular line, and Class II molar relationship. The maxillary incisors had excessive buccal root torque, throbbing pain, and dental mobility, with no visible bone coverage in the tomographic sections. The cephalometric analysis confirmed the skeletal Class II relationship (ANB, 11.6°; Wits appraisal, 14.2 mm) because of severe mandibular deficiency (SNB, 71.2°), aggravated by the vertical growth tendency (FMA, 27.3°). Changes in IMPA (108.1°) and U1-NA (0.9°; -2.9 mm) reflected the previous orthodontic attempt to compensate for the malocclusion. After periodontal and endodontic evaluation, a new treatment plan was developed. The incisors would be positioned in their bone bases, the mandibular first premolars would be extracted to create space for the second molars and increase the overjet, and the patient would be referred for orthognathic surgery. The patient was satisfied with the esthetic and functional results of this treatment.

Comparison of the facial profile attractiveness in Class III borderline patients after surgical or compensatory orthodontic treatment

Background

This study aimed to compare the facial profile attractiveness of Class III borderline patients after surgical or compensatory orthodontic treatment.

Material and Methods

The sample consisted of 60 borderline Class III malocclusion patients, divided into two groups: Group 1 (Surgical): 30 patients (16 male; 14 female) treated with orthodontic fixed appliances and bimaxillary orthognathic surgery. Mean initial age was 20.05 years (s.d.=2.40) and mean treatment time was 2.23 years (s.d.=0.82). Group 2 (Compensatory): 30 patients (13 male; 17 female) treated compensatorily with fixed appliances and Class III elastics. Mean initial age was 18.53 years (s.d.=4.35) and mean treatment time was 2.08 years (s.d.=0.67). Silhouettes of the facial profile were constructed obtained from the pretreatment and posttreatment lateral cephalograms and evaluated by orthodontists (N=41, 22 females and 19 males, mean age of 35.65 years), assigning scores from 1 (least attractive) to 10 (most attractive). Intergroup comparison of profile attractiveness was performed by Mann-Whitney test. For intragroup comparison of initial and final stages, the Wilcoxon test was used.

Results

At initial stage, the compensatory group presented a statistically significant greater attractiveness of the profile than the surgical group. With treatment, the surgical group presented significantly more improvement in facial profile than the compensatory group. At the final stage, profile attractiveness of surgical and compensatory groups was similar.

Conclusions

The facial profile attractiveness is similar in Class III patients after orthognathic surgery or compensatory orthodontic treatment. However, surgery provided more improvement in profile attractiveness than the compensatory treatment in Class III patients. Key words:Malocclusion, angle Class III, orthognathic surgery, corrective orthodontics.

Effects of different nose types on class II treatments for female patients

Background

The aim of this study was to evaluate the effect of different nose types on the perception of facial aesthetics following camouflage treatment and orthognathic surgery for skeletal class II female patients.

Methods

A pre-treatment profile photograph of a skeletal class II adult patient was selected from the department archive. Two constructed photographs were created to represent orthognathic surgery and camouflage treatments with the aid of computer software. A total of 18 constructed images was composed using three profiles (pre-treatment, post-camouflage, and post-orthognathic surgery) and six nose types. These photographs were shown to the three groups (orthodontists, plastic surgeons, and lay people), and they were asked to assign an attractiveness score to each photo ranging from 0 to 100, with 0 indicating the least attractive and 100 indicating the most attractive.

Results

For the convex nose profiles, anterior movement of the mandible obtained by orthognathic surgery did not result in a significant change in the scores given by the lay people. When surgical or camouflage treatment was not implemented and, instead, just rhinoplasty was performed for these profiles, there was a significant increase in the aesthetic scores given by all groups. For the straight nose profiles, orthognathic surgery increased the attractiveness scores given by all groups. Furthermore, for all the profiles, extraction treatment did not affect the aesthetic scores given by any of the groups (P > 0.05).

Conclusions

The lay people perceived that having a convex-bridged nose was a bigger problem than having a retrognathic profile. Overall, in terms of skeletal and dental orthodontic treatments, nose shape should be considered during the treatment planning process.

Primary Mandibular Deficiency Dentofacial Deformities: Occlusion and Facial Aesthetic Surgical Outcomes

PURPOSE

The purpose of the present study was to document the malocclusion and facial dysmorphology in primary mandibular deficiency (PMD) subjects with chronic obstructive nasal breathing before treatment and the outcomes after bimaxillary orthognathic, genioplasty, and intranasal surgery.

PATIENTS AND METHODS

A retrospective cohort study of PMD subjects undergoing bimaxillary, chin, and intranasal surgery was implemented. The predictor variables were grouped into demographic, anatomic, operative, and longitudinal categories. The primary outcome variables were the initial postoperative occlusion achieved at 5 weeks postoperatively (T₂) and that maintained long-term more than 2 years after surgery (T₄). Six occlusion parameters were assessed: overjet, overbite, coincidence of dental midlines, Angle classification, molar vertical, and transverse positions. A second outcome variable was the facial esthetic results. Photographs were analyzed to document 7 facial contour characteristics.

RESULTS

Forty subjects met the inclusion criteria. Their age at surgery averaged 32 years (range 13 to 63). The study included 25 females (63%). The findings confirmed that the occlusion after initial surgical healing (T₂) met the objectives for all parameters in 39 of the 40 patients (98%). Most patients (35 of 40; 88%) achieved and maintained a favorable occlusion for each parameter in the long-term (mean 5 years, 3 months). Subjects requiring counterclockwise rotation of the maxillomandibular complex were more likely to a have recurrent anterior open bite in the long-term. Facial contour deformities on presentation included weak chin (80%), deep labiomental fold (90%), everted lower lip (100%), short neck-to-chin length (88%), obtuse neck-to-chin angle (85%), weak mandible angles (93%), and "bunching" of the neck soft tissues (85%). Before surgery, 88% of the subjects exhibited a minimum of 5 of the 7 facial deformities. Correction of all 7 facial deformities was confirmed in 86% of the subjects in the long-term.

CONCLUSIONS

Most PMD subjects achieved and maintained a corrected occlusion in the long-term. In the untreated subjects, a "facial type" was identified. Orthognathic surgery proved effective in correcting the associated facial dysmorphology in most patients.

Impact of Orthognathic Correction of Class II Malocclusion on the Perception of Social Characteristics

Objective

To evaluate the influence on the perception of social characteristics after orthognathic treatment for the correction of Class II malocclusion.

Methods

A cross-sectional study was conducted with the participation of 240 observers who evaluated images of individuals before and after orthognathic surgery for the correction of malocclusion. Based on the images, two different questionnaires were applied containing 44 questions each for evaluating social competence, intellectual ability, psychological adjustment, and attractiveness. The mean scores for evaluations of the images were compared using the Mann-Whitney U test at 5% level of significance (α=0.05).

Results

Orthognathic treatment significantly (p<0.05) improved the evaluation of individuals in the requisites of the score attributed to the image (p=0.008), extroversion (p=0.026), happiness (p=0.006), self-confidence (p=0.046), and attractiveness (p=0.015).

Conclusion

Orthognathic treatment for the correction of Class II malocclusions has a positive effect on the perception of social characteristics of individuals. The individuals subjected to orthognathic surgery were evaluated as being more attractive, intelligent, socially competent, and psychologically adjusted.

Miniscrew-assisted multidisciplinary orthodontic treatment with surgical mandibular advancement and genioplasty in a brachyfacial Class II patient with mandibular asymmetry

This article describes the complex dental treatment of a 43-year-old man with skeletal Class II, mandibular asymmetry, severe brachyfacial pattern, Class II Division 2, canting of the occlusal plane, and an increased curve of Spee. To achieve optimal results, we adopted a multidisciplinary approach to treatment, involving periodontics, oral surgery, orthodontics, maxillofacial surgery, and prosthetics specialists. After periodontal treatment, miniscrews were placed to correct the occlusal plane canting and the excessive curve of Spee with orthodontic treatment. The surgical treatment plan consisted of a bilateral asymmetric sagittal split osteotomy for mandibular advancement and genioplasty. The patient had an infection after the surgery at the site of the right fixation plate, so the plate was removed, and active orthodontic treatment was continued and finished. Mandibular first molar implants and maxillary ceramic crowns using the Digital Smile Design method (Digital Smile Design, Doral, FL) were placed at the end of orthodontic treatment. The patient was satisfied with the treatment results and with his facial and dental appearance, as well as his oral function. The 2-year follow-up pictures show a stable result both esthetically and functionally.

Three-dimensional aesthetic assessment of class II patients before and after orthognathic surgery and its association with quantitative surgical changes

The aim of this study was to compare evaluations of the aesthetic outcome of class II orthognathic patients, as performed by observers with varying expertise using three-dimensional (3D) facial images, and to examine the relationship of aesthetic ratings in relation to quantitative surgical changes. Pre- and postoperative 3D facial images of 20 surgically treated class II patients (13 female, 7 male) were assessed for aesthetics by orthodontists, maxillofacial surgeons, and laypeople. Attractiveness ratings for the lips, chin, and overall facial aesthetics were evaluated on a 5-point Likert scale. Correlation between the aesthetic scores was obtained and quantitative surgical changes were examined. For all groups of observers, significant improvements in attractiveness scores were found, especially for the chin assessment. Orthodontists perceived the greatest improvement and laypeople the smallest. Overall, laypeople scored higher with less variability, but with lower intra- and inter-observer agreement. No significant correlation was found between the aesthetic improvement and soft tissue surgical changes. To avoid patient dissatisfaction, it is important to bear in mind that the demands and perception of aesthetic improvement after orthognathic surgery are higher for clinicians than for the general public.

Effect of orthognathic surgery on profile esthetics in Class II:1 malocclusions

OBJECTIVES

To measure the effect of orthognathic surgery on Class II:1 profile silhouette esthetics and to identify pretreatment parameters and thresholds for consistent esthetic improvement.

METHODS

Pre- and posttreatment black profile silhouettes of 20 patients with Class II:1 malocclusion who had received combined orthodontic/orthognathic treatment were evaluated retrospectively by 20 European orthodontists and laypeople each using a visual analogue scale (VAS). A variety of pretreatment skeletal and facial angles were measured cephalometrically and on the silhouette profiles. Descriptive statistics and Pearson's correlation coefficients were calculated.

RESULTS

The population showed a mean VAS improvement of 12.6%. VAS changes were significantly and directly related to pretreatment ANB in all evaluator groups (r = 0.48-0.59), whereas the interrelation with the degree of pretreatment profile convexity angle was less clear and statistically significant for the orthodontic evaluators only (r = -0.34 to -0.51). The highest correlation coefficients in all evaluator groups were seen for the relationship with pretreatment VAS scores (r = -0.64 to -0.73).

CONCLUSION

The lower the pretreatment VAS score and the profile convexity angles or the larger the pretreatment ANB angles were, the more the VAS improved. Pretreatment thresholds for consistent improvements were as follows: VAS score < 20 mm, ANB > 8°, and profile angle ≤ 155°.

Evaluation of 3-dimensional superimposition techniques on various skeletal structures of the head using surface models

Objectives

To test the applicability, accuracy, precision, and reproducibility of various 3D superimposition techniques for radiographic data, transformed to triangulated surface data.

Methods

Five superimposition techniques (3P: three-point registration; AC: anterior cranial base; AC + F: anterior cranial base + foramen magnum; BZ: both zygomatic arches; 1Z: one zygomatic arch) were tested using eight pairs of pre-existing CT data (pre- and post-treatment). These were obtained from non-growing orthodontic patients treated with rapid maxillary expansion. All datasets were superimposed by three operators independently, who repeated the whole procedure one month later. Accuracy was assessed by the distance (D) between superimposed datasets on three form-stable anatomical areas, located on the anterior cranial base and the foramen magnum. Precision and reproducibility were assessed using the distances between models at four specific landmarks. Non parametric multivariate models and Bland-Altman difference plots were used for analyses.

Results

There was no difference among operators or between time points on the accuracy of each superimposition technique (p>0.05). The AC + F technique was the most accurate (D<0.17 mm), as expected, followed by AC and BZ superimpositions that presented similar level of accuracy (D<0.5 mm). 3P and 1Z were the least accurate superimpositions (0.79<D<1.76 mm, p<0.005). Although there was no difference among operators or between time points on the precision of each superimposition technique (p>0.05), the detected structural changes differed significantly between different techniques (p<0.05). Bland-Altman difference plots showed that BZ superimposition was comparable to AC, though it presented slightly higher random error.

Conclusions

Superimposition of 3D datasets using surface models created from voxel data can provide accurate, precise, and reproducible results, offering also high efficiency and increased post-processing capabilities. In the present study population, the BZ superimposition was comparable to AC, with the added advantage of being applicable to scans with a smaller field of view.

Soft tissue changes and its stability as a sequlae to mandibular advancement

Purpose of the Study:

To predict the changes and evaluate the stability that occurs in the soft tissues following the skeletal movement subsequent to surgical advancement of the mandible through bilateral sagittal split osteotomy and to provide the patient reliable information with regard to esthetic changes that can be expected following the treatment.

Materials and Methods:

Twenty adult patients diagnosed with skeletal class II malocclusion and underwent bilateral sagittal split osteotomy for mandibular advancement by a mean of 8 mm using rigid fixation were included in the study. Soft tissue changes brought about by the surgical procedure and their stability over a period of time were evaluated prospectively using 12 linear (4 vertical and 8 horizontal) and 4 angular measurements on profile cephalograms which were taken preoperatively after the pre-surgical orthodontics (T1) and postoperatively with duration of 1 month (T2) and 6 months (T3) respectively.

Results:

It was observed that compared to the linear measurements, the angular measurements showed significant changes. The improvement in the esthetic outcome is a direct reflection of the angular changes whereas the linear changes played a contributing role. Following mandibular advancement surgery the profiles of the patients was perceived to have improved with reduction in the facial convexity, an increase in the lower facial height, decrease in the depth of the mentolabial sulcus and improvement in the lip competency with lengthening, straightening and thinning of the lower lip.

Conclusion:

The soft tissue response and its stability depends on the stability of the surgical procedure itself, postsurgical growth and remodeling of the hard tissues and soft tissue changes as a result of maturation and aging.

True vertical validation in facial orthognathic surgery planning

Objectives: To validate the effectiveness of the original standards of True Vertical (TV) Subnasal Line in orthognatic surgery planning. The present study evaluates the changes occurring in patients with skeletal Class II alterations programmed for orthognathic surgery with a view to improving their facial profile. Study design: We showed a series of black profiles (composed by a first control group of subjects with normal occlusion, and another two additional groups comprised patients before –Group 2- and after orthognatic surgical correction of Class II malocclusion -Group 3-) for three groups of observers (orthodontists, surgeons and laypeople). The facial images became black silhouettes in order to determine a series of parameters (including aesthetic assessment) by means of the observers. Their observation were assessed using a 5-point Likert scale. Results: The sample was composed of 52 profile’s subjects who were tested for a total of 72 observers. Aesthetic assessment yielded mean scores of 2.57, 1.67 and 2.46 for groups 1, 2 and 3, respectively. There was a statistically significant difference (p<0.001) between group 1 versus group 2. There were no significant differences in terms of observer assessment of aesthetics, with the exception of a wider perception range among the orthodontists. Regarding the studied profile measures, significant differences were recorded for point B’ and Pg’ (p<0.02) between groups 2 and 3 (i.e., pre- versus post-surgery). Conclusions: The results of our study suggest the subnasale vertical and sagittal measures of the lower third of the face are decisive in facial aesthetics, and therefore also for the planning of orthognathic surgery. Consequently, these aesthetic parameters can be used as an objective tool for the planning of orthodontic treatment.

Key words:Facial profile, Class II, orthognathic surgery, cephalometric analysis, facial soft tissue, subnasale vertical.

Changes in facial profile after maxillomandibular advancement surgery for obstructive sleep apnea syndrome

The aim of this study was to assess changes in the profile of adult male patients treated for obstructive sleep apnea syndrome (OSAS) with maxillomandibular advancement (MMA) surgery and to measure patient perception of changes compared with that of different panels.

MATERIALS AND METHODS

Fifteen consecutive apneic patients displaying a wide variety of morphological types, mean age 42 years (20-59), a BMI of 26.60 kg/m(2) (22-29), a mean initial Apnea Hypopnea Index (AHI) of 50.9 (19-85), underwent MMA. Assessment was done by facial photography, lateral cephalographs (Tweed analysis modified by Riley and Delaire architectural analysis), polysomnographic records and a validated self-assessment questionnaire. Patients' pre- and postoperative profiles were taken from photographs using Photoshop 7™ software. Their darkened outlines were shown randomly in positions A or B (pre- and postoperative) to panels composed of orthodontists (n=40), fine arts students (n=50) and lay persons (n=50) who were requested to choose the most attractive profiles.

RESULTS

The MMA success rate for OSAS was 80% (12/15) for an AHI less than 15, with no surgical complications. All patients reported a reduction of their symptoms and 14 out of 15 were satisfied with the esthetic outcome. Mean advancement was 8.4mm (3.0-10.0) for the maxilla and 10.8mm (10.0-13.0) for the mandible. Following MMA, 12 out of 15 exhibited maxillary protrusion and six out of 15 mandibular protrusion. The mean change in the nasolabial angle was -5.7° (-27°; 14°). The postoperative profiles were preferred by 85% of the combined panels (P=<0.001), showing no significant difference from one panel to another. No skeletal characteristic could be correlated with the esthetic preference. Upper lip retrusion, open nasolabial angle and dolichofacial type emerged as positive preoperative predictors of esthetic preference.

CONCLUSION

The profile changes following MMA were favorably perceived in the majority of cases. However, specific orthodontic preparation could be offered to patients with pronounced preoperative protrusion.

Surgical prediction of skeletal and soft tissue changes in treatment of Class II

INTRODUCTION

The purpose of this study was to study the treatment outcomes and the accuracy of digital prediction and the actual postoperative outcome with Dolphin program on subjects presenting Class II malocclusions.

METHODS

Forty patients underwent surgical mandibular advancement (Group 1) and 40 underwent combined surgery of mandibular advancement and maxillary impaction (Group 2). The available pre surgical (t₁) and a minimum of 12 months post surgical (t₂) cephalometric radiographs were digitized. Predictive cephalograms (t₃) for both groups were traced.

RESULTS

At all times evaluated, Group 1 displayed a shorter mandibular length and Group 2 had a longer lower face. In both groups the surgical interventions (t₂) were greater than initially predicted. There was no significant difference between groups with regards to overjet, overbite and soft tissue measurements.

CONCLUSIONS

In both groups surgeries were more extensive than planned. Facial convexity and the distance of the lips to cranial base presented similar values between t₂ (post surgical) and t₃ (predicted).

Long-term skeletal and profile stability after surgical-orthodontic treatment of Class II and Class III malocclusion

OBJECTIVE

The purpose of this perspective research was to study the long-term stability of skeletal, dentoalveolar and soft tissue after orthognathic surgery in subjects presenting with Class II and Class III malocclusions.

METHODS

The available digitized cephalometric radiographs, including pretreatment (t0), presurgery (t1), a minimum of 12 months postsurgery (t2) and at least 3 years after the orthosurgery treatment (t3) were taken between 1998 and 2010. In Group 1 mandibular advancement and in Group 2 mandibular advancement and maxillary impaction surgery were performed for correction of Class II. In Group 3 maxillary advancement and in Group 4 surgical maxillary advancement with mandibular setback, for correction of Class III.

RESULTS

In all the phases mandibular length was shorter in Group 1, and the inferior third of the face was longer in Group 2. Before the surgery there was greater maxillary deficiency in Group 3 than Group 4 and mandibular length was longer in Group 4.

CONCLUSION

In Groups 1 and 2, at retention phase, relapse occurred due to the increase in mandibular plane, whereas the surgeries performed in Groups 3 and 4 remained stable.

Assessing anteroposterior basal bone discrepancy with the Dental Aesthetic Index

Objective:

To investigate dental appearance and cephalometric features, using a sample of orthognathic and/or orthodontic patients. A special interest was to identify the relationship of the Dental Aesthetic Index (DAI) with anteroposterior basal bone discrepancy (APBBD) and cephalometric indicators.

Materials and Methods:

A full sample of 159 patients in two Japanese hospitals was used. Each patient was assessed with a preorthodontic dental cast and cephalometric radiography.

Results:

Malocclusion with APBBD was more prevalent among high DAI subjects (P  =  .034, OR  =  1.04, 95% CI: 1.00–1.08), Class III malocclusion patients (P  =  .048, OR  =  2.32, 95% CI: 1.01–5.34) and male patients (P  =  .008, OR  =  2.96, 95% CI: 1.33–6.61). Participants scoring 88 points (the highest score in this sample) of the DAI had 16.84 times the risk of APBBD of those who scored 17 points (the lowest score in this sample). Patients with APBBD presented with a greater adjusted ANB angle (t  =  −8.10, P &lt; .001) and a larger adjusted A-B/NF appraisal (t  =  −9.65, P &lt; .001). The SNA angle (P &lt; .001), the SNB angle (P  =  .002), the adjusted ANB angle (P  =  .001), and the adjusted A-B/NF appraisal (P  =  .035) were associated with DAI scores in cubic regression models.

Conclusion:

This study has demonstrated a relationship between the DAI and APBBD. Feasibility of using the adjusted ANB angle and the adjusted A-B/NF appraisal to assess severity of APBBD has been confirmed. The DAI may provide a supportive method to evaluate orthognathic needs. Future investigations are indicated.

Photos vs silhouettes for evaluation of African American profile esthetics

INTRODUCTION

Patient photos and silhouettes are commonly used in clinical evaluations and orthodontic research to evaluate profile esthetics. The purpose of this study was to determine whether the use of photos or silhouettes is a more appropriate method of evaluating African American profile esthetics and whether there are different profile esthetic preferences among clinicians when using photos compared with silhouettes.

METHODS

Pretreatment records of 20 adolescent African American patients were selected (10 male, 10 female) from the orthodontic clinic at the Albert Einstein Medical Center in Philadelphia. Each patient's profile photo was digitally changed with imaging software (Dolphin Imaging and Management Solutions, Chatsworth, Calif) to fabricate a series of 7 photos and 7 silhouettes with lip positions at uniform distances relative to Ricketts' E-line standard. Fifteen raters consisting of orthodontic faculty and residents were asked to select the most esthetically pleasing profile from each patient's photo series and silhouette series.

RESULTS

More rater preferences for the photographs (86%) were within the acceptable esthetic range (within 2 mm of the E-line in either direction) than were their preferences for silhouettes (66%) (P <0.001). Flatter profiles with less lip projection than the esthetic norm were more often preferred in the silhouettes than in the photos. Thirty-one percent of the silhouettes preferred by the raters were flatter than the norm compared with 9% of the photos (P = 0.003). Fuller profiles were preferred in only 3% of the silhouettes and 5% of the photos (P = 0.6).

CONCLUSIONS

Esthetic attractiveness of faces of African American orthodontic patients is rated differently in photos and silhouettes. When evaluating soft-tissue esthetic profile preferences, rater preferences in the photographs were closer to the established esthetic norm than were their preferences in the silhouettes. Using silhouettes to evaluate patient esthetics could influence clinicians or researchers to select profiles that are flatter than the established esthetic norm.

The ability of orthodontists and laypeople to discriminate mandibular stepwise advancements in a Class II retrognathic mandible

OBJECTIVES

This study analysed the ability of orthodontists and laypeople to discriminate mandibular stepwise advancements.

MATERIALS AND METHODS

Four pictures (in duplicate) were taken of a male patient with Class II malocclusion and mandibular deficiency with the mandible positioned in habitual maximum intercuspation (HMI) and with stepwise advancements of 2mm, 4mm and 6mm. These images were examined by orthodontists (n=30) and laypeople (n=30). The Wilcoxon signed-rank test was used to evaluate intra-examiner agreement. Intra-examiner ability to discriminate stepwise mandibular advancements was examined by Friedman's test. A Mann-Whitney's test was carried out to analyse score difference between orthodontists and laypeople. Type I error (alpha) was set as 5% for all statistical tests.

RESULTS

We observed a satisfactory to excellent level of methodological reliability. While laypeople were able to notice mandibular advancements ≥4 mm (p<0.05), orthodontists were able to observe mandibular advancements ≥2 mm (p<0.05). The orthodontists were more critical than laypeople with regard to the facial profile evaluation when facial convexity increased (p<0.001), but no significant difference was observed when the sagittal maxillo-mandibular relationship approached normality (p<0.05).

CONCLUSIONS

Considering that the mean sagittal mandibular growth due to the use of functional orthopaedic appliances is reported in the literature as 2mm, it seems that laypeople may not able to discriminate this amount of change in facial-profile attractiveness.