Improved facial outcome assessment using a 3D anthropometric mask

The capacity to process three-dimensional facial surfaces to objectively assess outcomes of craniomaxillofacial care is urgently required. Available surface registration techniques depart from conventional facial anthropometrics by not including anatomical relationship in their analysis. Current registrations rely on the manual selection of areas or points that have not moved during surgery, introducing subjectivity. An improved technique is proposed based on the concept of an anthropometric mask (AM) combined with robust superimposition. The AM is the equivalent to landmark definitions, as used in traditional anthropometrics, but described in a spatially dense way using (～10.000) quasi-landmarks. A robust superimposition is performed to align surface images facilitating accurate measurement of spatial differences between corresponding quasi-landmarks. The assessment describes magnitude and direction of change objectively and can be displayed graphically. The technique was applied to three patients, without any modification and prior knowledge: a 4-year-old boy with Treacher-Collins syndrome in a resting and smiling pose; surgical correction for hemimandibular hypoplasia; and mandibular hypoplasia with staged orthognathic procedures. Comparisons were made with a reported closest-point (CP) strategy. Contrasting outcomes were found where the CP strategy resulted in anatomical implausibility whilst the AM technique was parsimonious to expected differences.     

Three-dimensional analysis of facial morphology before and after orthognathic surgery

A method for three-dimensional analysis of the facial hard- and soft-tissue morphologies is described. The soft-tissue analysis consisted of calculating three-dimensional values of reference points on the face by perspective transformation of their values in two pairs of photographs, taken simultaneously, from the right and left sides of the face. The shape of the mandible was analyzed three-dimensionally by the simultaneously taken frontal and lateral cephalograms. The hard- and soft-tissue changes were analyzed with the method in 28 patients in whom mandibular prognathism had been corrected by orthognathic surgery. The magnitude of the surgically-produced soft tissue volumetric changes in the anterior mandibular region was proportional to the posterior movement of the mandible. Asymmetry of the face also improved in response to correction of lateral deviation of the mandible and a close correlation between the directional indices of asymmetry of the hard and soft tissues was observed. Thus, the method was found to be quite useful for the analysis of facial morphology in jaw deformity.     

The reproducibility of the head position for a laser scan using a novel morphometric analysis for orthognathic surgery

The aim of this study was to evaluate the reproducibility of the head position for a three-dimensional soft tissue laser scan (lasergraph) using thin-plate splines, for orthognathic surgery planning and follow-up. 60 laser scans of five subjects (12 scans per subject) were obtained at specified intervals. The head was positioned in the lateral view using a spirit level, an engineering device for setting horizontal surfaces, to adjust the Frankfort horizontal plane parallel to the ground. The projection of a narrow beam of longitudinal laser light was used to adjust the axial plane for the frontal view. These scanned images (lasergraphs) were digitised and the co-ordinates of the landmarks recorded. The digitised laser scans were compared using thin-plate splines analysis. The mean difference between the scans due to variations in head position was 0.0135 +/- 0.0109 g x cm2/ sec2 in the lateral view and 0.0090 +/- 0.0054 g x cm2/sec2 in the frontal view. This represents an overall distortion error of less than 2% when following up the surgical change of a typical bimaxillary osteotomy case with 6 mm maxillary advancement and 3 mm mandibular set-back. It is concluded that facial laser scans (lasergraphs) with the Frankfort horizontal plane set using a head rest and spirit level, and the axial plane set using projection of a vertical laser light on the facial midline, are highly reproducible.     

Changes in the facial soft-tissue profile after mandibular orthognathic surgery

Objectives

To investigate the correlation between soft- and hard-tissue changes after mandibular orthognathic surgery, to generate precise prognostic values for the esthetic treatment outcome of the facial profile.

Material and Methods

In this retrospective study, sagittal changes in the facial soft tissue profile in relation to surgical changes in hard structures after mandibular osteotomy were examined. The sample population included 144 reported adult patients aged 17–50 years who had received combined mandibular orthognathic surgery and orthodontic treatment at the Department of Orthodontics, Ludwig-Maximilians University of Munich, Germany. Both mandibular advancement and mandibular setback cases in monognathic and bignathic osteotomy procedures were included. All subjects had undergone rigid fixation. A cephalometric analysis of presurgical and postsurgical cephalograms was performed, and the correlations between hard-tissue and soft-tissue change ratios were evaluated using a bivariate linear regression analysis.

Results

The lower lip, represented by the landmark Labrale inferius (Li), followed the lower incisor (Ii) by 77%. The soft-tissue B-point (B’) followed the B-point (B) by 97% and the soft-tissue Pogonion (Pg’) followed the Pogonion (Pg) by 97% in a linear correlation.

Conclusion

The scatterplots show a distinct linear correlation and no significant difference in the direction of the movement. A wider spread for the lower lip (Li/Ii) indicates a lower predictability of the expected lip position, whereas a narrow spread of the chin values (B’/B and the Pg’/Pg) reveals a very good predictability of the postoperative chin position.

Clinical relevance

This study contributes valid data for the soft-tissue profile prediction in orthognathic surgery.

     

3D stereophotogrammetric image superimposition onto 3D CT scan images: the future of orthognathic surgery. A pilot study

The aim of this study was to register and assess the accuracy of the superimposition method of a 3-dimensional (3D) soft tissue stereophotogrammetric image (C3D image) and a 3D image of the underlying skeletal tissue acquired by 3D spiral computerized tomography (CT). The study was conducted on a model head, in which an intact human skull was embedded with an overlying latex mask that reproduced anatomic features of a human face. Ten artificial radiopaque landmarks were secured to the surface of the latex mask. A stereophotogrammetric image of the mask and a 3D spiral CT image of the model head were captured. The C3D image and the CT images were registered for superimposition by 3 different methods: Procrustes superimposition using artificial landmarks, Procrustes analysis using anatomic landmarks, and partial Procrustes analysis using anatomic landmarks and then registration completion by HICP (a modified Iterative Closest Point algorithm) using a specified region of both images. The results showed that Procrustes superimposition using the artificial landmarks produced an error of superimposition on the order of 10 mm. Procrustes analysis using anatomic landmarks produced an error in the order of 2 mm. Partial Procrustes analysis using anatomic landmarks followed by HICP produced a superimposition accuracy of between 1.25 and 1.5 mm. It was concluded that a stereophotogrammetric and a 3D spiral CT scan image can be superimposed with an accuracy of between 1.25 and 1.5 mm using partial Procrustes analysis based on anatomic landmarks and then registration completion by HICP.     

Efficacy of steroid treatment for sensory impairment after orthognathic surgery.

PURPOSE: Steroid hormones are therapeutic for motor and/or sensory dysfunctions caused by nerve injury. However, the timing for giving such medicine is unclear. This study aimed to estimate the efficacy of steroid treatment and determine an appropriate start time after sensory impairment. PATIENTS AND METHODS: Twenty-seven patients with sensory impairment who received orthognathic surgery were classified into groups called 1W (n = 6), 3W (n = 6), or 6W (n = 8) group on the basis of start time for steroid treatment, being 1 week, 3 weeks, or 6 weeks after surgery, respectively, and a no steroid treatment (NST) group (a control group) (n = 6) that did not receive treatment for 10 to 12 weeks after surgery. Sensory impairment was diagnosed if postoperative first week mechanical-touch threshold was over 4.0 as measured by Semmes aesthesiometer. Prednisolone treatment was administered orally to patients at 30 mg for 7 days, 15 mg for 4 days, and 5 mg for 3 days. Mechanical-touch threshold and thermal perceptions were compared before and after treatment. RESULTS: At 1 week postoperatively, there were no significant differences in mechanical-touch threshold among the 4 groups (analysis of variance, P >.05). Changes in mechanical-touch threshold in the 1W group showed no significant improvement (analysis of variance, P >.05), but in the 3W and 6W groups, there were significant differences compared with the NST group (Dunns methods, P <.05). CONCLUSIONS: Steroid treatment for sensory impairment after orthognathic surgery has the potential to accelerate recovery and it appears desirable to start treatment later than 1 week postoperatively.     

Time benefits of 3D planning in orthognathic surgery: a systematic review

This systematic review aimed to evaluate the possible time benefits when using 3-dimensional (3D) planning prior to orthognathic surgery compared with a conventional method alone. The databases utilised were PubMed, Medline, Web of Science, and the Cochrane Library. Studies were selected based on eligibility criteria and reviewed independently by two authors. A total of eight studies were included. The review concludes that there are a limited number of studies with the appropriate experimental protocols in place. Therefore, although there is low-grade evidence to suggest that 3D planning in orthognathic surgery is more time-efficient, the field would benefit from the publication of more rigorous studies.     

Evaluation of facial soft tissue asymmetric changes in Class III patients after orthognathic surgery using three-dimensional stereophotogrammetry

The aim of this study was to investigate changes in facial soft tissue asymmetry over time after orthognathic surgery in Class III patients using three-dimensional stereophotogrammetry. The study included 101 patients with a skeletal Class III malocclusion (72 female, 29 male; age range 19–53 years, mean age 28.6 years) who underwent orthognathic surgery. The minimum follow-up was 12 months. Three-dimensional photographs were acquired using the 3dMDtrio stereophotogrammetry system, and 21 anthropometric landmark positions were evaluated at three time points: before surgery (T0), 6 months (T1) and 12 months (T2) after surgery. Facial asymmetry was assessed and classified as follows: 0–2 mm, mild; 2–5 mm, moderate;> 5 mm, severe. The average distance for whole face asymmetry differed between T0 (median 0.76 mm) and T1 (median 0.70 mm); however, there was no statistically significant difference at any time point. The chin volume asymmetry score differed significantly between T0 (median 1.11 mm) and T1 and T2 (median 1.08 mm for both; P < 0.001 and P = 0.001, respectively), but not between T1 and T2 (P = 0.061). The study findings indicate that the asymmetry of the facial soft tissues has the potential to return after 6 months, without reaching the baseline.     

Bimaxillary orthognathic surgery in a patient with long face: a case report

The primary characteristics of long face patients are gummy smile and/or anterior open bite. Consequently, correction of esthetic and functional problems are especially important for long face patients. Since orthodontic therapy alone is not sufficient to solve the problem, orthognathic surgical approach is indicated for these patients. In this report, orthognathic surgical therapy of a severe long face patient with similar findings was presented. Following clinical and cephalometric examination and preoperative orthodontic therapy, a Le Fort I osteotomy, a bilateral sagittal split osteotomy, and vertical and horizontal reduction genioplasties were performed. Alternative surgical therapies, complications, and the effects on the upper respiratory tract are also discussed.     

The optical surface scan as an alternative to the cephalograph for soft tissue analysis for orthognathic surgery

The aim of this study was to compare cephalographs and optical surface scanner images (lasergraphs) by measuring the lipincisor relationship, the nasolabial angle, nasal tip projection, the nasofacial angle, the nasomental angle, and the labiomental angle in pre- and postoperative orthognathic surgery patients. The results showed that the methods were comparable, but the optical surface scan (lasergraph) could be used to greater advantage for pre- and postoperative assessment of soft tissue changes with orthognathic surgery, because of its clarity and 3-dimensional potential.     

The fate of miniplates in facial trauma and orthognathic surgery: a retrospective study

The fate of 279 Champy miniplates used routinely as permanent implants over a 5-year-period in the management of maxillofacial trauma and orthognathic surgery has been analysed retrospectively. Trauma patients (62) and orthognathic patients (47) were analysed separately; in each group those patients who had plates removed were compared to the patients with retained plates. This study indicates that the morbidity of retaining plates is within acceptable limits and that the routine removal of plates at 3 months may be unnecessary.     

Integration of intraoral digital scans with a 3D facial scan for anterior tooth rehabilitation

This article describes a digital technique that combines intraoral digital scans with a 3-dimensional facial scan to predict the outcome of prosthodontic treatment of anterior teeth at the treatment planning phase. This approach may increase patient acceptance of the definitive treatment, as the altered facial appearance is visualized with definitive prosthodontic restorations, thereby improving communication before treatment begins.     

Computer-assisted orthognathic surgery for correction of facial asymmetry: results of a randomised controlled clinical trial

In this randomised controlled clinical trial, 2 homogeneous groups of patients with facial asymmetry (n = 10 in each) were treated by either classic or computer-assisted orthognathic corrective surgery. Differences between the 2 groups in the alignment of the lower interincisal point (p = 0.03), mandibular sagittal plane (p = 0.01), and centring of the dental midlines (p = 0.03) were significant, with the digital planning group being more accurate.     

A new method for the 3D measurement of postoperative swelling following orthognathic surgery

OBJECTIVE: To describe a new method for measuring facial swelling following orthognathic surgery using a 3D laser-scanning device. DESIGN: Prospective clinical trial. Setting and Sample Population -- University Dental Hospital, Wales College of Medicine, Biology Life and Health Sciences. Three subjects requiring bi-maxillary orthognathic surgery were recruited for the study. EXPERIMENTAL VARIABLES: Laser-scanned images of the subjects were obtained under a reproducible and controlled environment with two Minolta Vivid 900 (Osaka, Japan) optical laser-scanning devices assembled as a stereo-pair. A set of left and right scanned images was taken for each subject and each scan took an average of 2.5 s. 3D laser scans were recorded over six time periods (T1 -- pre-surgical scan, postoperatively: T2 -- 1 day, T3 -- 1 week, T4 -- 1 month, T5 -- 3 months and T6 -- 6 months). OUTCOME MEASURE: Facial scans from different time periods were overlaid onto the baseline (T6) facial scan to determine the reduction and changes in swelling following orthognathic surgery. RESULTS: The results showed that swelling could be accurately quantified following surgery. Furthermore, there was a significant reduction in the amount of swelling 1 month postoperatively. Furthermore, the facial morphology returned to approximately 90% of the baseline facial scan at 3 months. CONCLUSION: The 3D laser-scanning device and the method described was a reliable and accurate measure of facial swelling following surgery.     

Self-assessment of facial form oral function and psychosocial function before and after orthognathic surgery: a retrospective study.

Orthognathic surgery is a well-accepted treatment for patients with skeletal discrepancies. The primary motivation of many patients who seek orthognathic surgery is esthetics and not for correction of functional disability. The treatment is incomplete if the surgeon attempts to correct the physical deformity alone without adequate understanding and regard for the emotional framework. The purpose of this study is aimed at patient's self-perceptions of facial form oral function and psychosocial function before and after orthognathic surgery. Fifty patients were included in the study, of which 21 were used as control. Twenty-two questions were asked to evaluate the problem in all four areas as mentioned earlier. Each question takes a score from one to five. In group I, the internal consistency of each scale indicates moderate to high internal reliability, ranging from alpha = 0.71 for general health to alpha = 0.88 for psychosocial problem. In group II, except for functional problems, the internal consistency of each scale has moderate to high reliability. The psychological wellbeing of an orthognathic surgery patient is enhanced by careful preoperative counseling regarding the expected surgical treatment objectives, the operative course, and the expected postoperative sequelae. Patients who undergo orthognathic surgery readily accept the changes in their postoperative appearance and are satisfied with achieved results.     

Evaluation of border movement of the mandible before and after orthognathic surgery using a kinesiograph

PurposeThe purpose of this study was to examine the changes in the mandibular border movement between class II and class III jaw deformity patients before and after orthognathic surgery, by using the same device.Subjectsand Methods: Eighty one patients (28 in class II and 53 in class III) who underwent sagittal split ramus osteotomy (SSRO) with Le Fort I osteotomy using absorbable plate fixation and 27 controls with normal occlusion were enrolled. Mandibular border movement (observed using a kinesiograph) was recorded with a mandibular movement measure system (K7) before surgery, and at 6 months and 1 year after surgery. Time-course changes of 5 components of the mandibular border movement (MVO: Maximum vertical opening, CO to MAP: Maximum antero-posterior movement from centric occlusion, MLDL: maximum lateral deviation left, MLDR: maximum lateral deviation right, CO to MO: centric occlusion to maximum opening) were compared between classes II, III and controls statistically. The relationship between lateral cephalometric measurements and the components of mandibular border movement was also examined.ResultsThere was a significant difference in CO to MAP (P = 0.0025) and CO to MO (P < 0.0001) between class II and class III in the time-course change.In class III, mean and standard deviation of MVO were 44.5 ± 6.7 mm before surgery and 39.8 ± 6.8 mm after 1 year. Mean and standard deviation of CO to MAP were 25.2 ± 6.8 mm before surgery and 21.5 ± 7.9 mm after 1 year. Mean and standard deviation of CO to MO were 53.4 ± 9.0 mm before surgery and 47.3 ± 8.4 mm after 1 year.In class II, mean and standard deviation of MVO were 38.8 ± 5.8 mm before surgery and 36.2 ± 7.4 mm after 1 year. Mean and standard deviation of CO to MAP were 18.0 ± 6.3 mm before surgery and 17.8 ± 7.4 mm after 1 year. Mean and standard deviation of CO to MO were 43.1 ± 7.5 mm before surgery and 39.6 ± 10.5 mm after 1 year.In MVO, CO to MAP and CO to MO, the values after 1 year did not significantly reach the pre-operative values in class III (P = 0.0001, P = 0.0007 and P < 0.0001), although there was no significant difference between pre-operation and after 1 year in class II.In CO to MO, class II (mean and standard deviation 39.6 ± 10.5 mm) and class III (mean and standard deviation 47.3 ± 8.4 mm) still remained smaller values than control (mean and standard deviation 52.7 ± 9.2 mm) after 1 year (P < 0.0001 and P = 0.0095).ConclusionThis study suggests that bi-maxillary surgery can have more influence on the reduction in the range of mandibular border movement including vertical or antero-posterior motion than lateral deviation motion, in both groups. The difference in the time-course change in the mandibular border movement between the groups might depend more on the mandibular length than on the movement direction of the mandible by surgery such as advancement or setback.     

Efficacy of gastric aspiration to reduce postoperative vomiting after orthognathic surgery: double-blind randomised clinical trial

Orthognathic surgery is a treatment modality indicated to correct dentofacial deformities. Postoperative vomiting can be associated with multifactorial origin mainly correlated to patient-related symptoms, anaesthetic and surgical factors. Swallowed blood has been related to one of those multifactorial vomiting causes. This present study was to compare the efficacy of gastric aspiration after bimaxillary orthognathic surgery. A double blind randomised clinical trial was carried out and patients were divided in two groups (n = 44/39 respectively). There was statistically significant difference between the control and study groups in the overall incidence of vomiting (p = 0.031) A stratified analysis by sex between both groups was performed demonstrating a four-fold eduction in the odds for vomiting events independent of patient gender (OR = 0.24; 95% CI 0.07 to 0.72). Gastric aspiration after orthognathic surgery can reduce the effects of postoperative vomiting decreasing inpatient period and, consequently, hospitalisation costs.     

3D evaluation of postoperative swelling using two different cooling methods following orthognathic surgery: a randomised observer blind prospective pilot study

Orthognathic surgery is associated with side effects including severe postoperative swelling, pain, neurological dysfunction and trismus. The beneficial effects of localised cold treatment on postoperative swelling have been described. Topographical considerations make it difficult to quantify facial swelling. A new and promising method to measure facial swelling seems to be optical face scanning. This study aimed to evaluate the 3D optical scanner to measure soft tissue swelling following orthognathic surgery. Postoperative swelling was treated either with conventional cooling by cold packs or with the water-circulating cooling device Hilotherm Clinic. Secondary endpoints in each group included postoperative pain, neurological complaints, duration of hospital stay, trismus and patient satisfaction. The use of the cooling device by Hilotherm significantly reduced postoperative swelling, pain and hospital duration compared with conventional cooling. Postoperative trismus and satisfaction with the cooling method was significantly higher in the Hilotherm group compared with conventional cooling. No differences were observed concerning neurological score and outcome. In conclusion, 3D optical scanning is a simple and precise method of quantifying face swelling after orthognathic surgery. Hilotherm significantly reduces swelling and duration of hospital stay compared with conventional cooling.