Three-Dimensional Nasal Alterations in Le Fort I Advancement: Linear Measurements, Angles, Nasal Indices, and Volume Differences

Photographic Parameters in Three-Dimensional Facial Image Acquisition. A Scoping Review

OBJECTIVE

Orthognathic surgery is a viable and reproducible treatment for facial deformities. Despite the precision of the skeletal planning of surgical procedures, there is little information about the relations between hard and soft tissues in three-dimensional (3D) analysis, resulting in unpredictable soft tissue outcomes. Three-dimensional photography is a viable tool for soft tissue analysis because it is easy to use, has wide availability, low cost, and is harmless. This review aims to establish parameters for acquiring consistent and reproducible 3D facial images.

METHODS

A scoping review was conducted across PubMed, SCOPUS, Scientific Electronic Library Online (SciELO), and Web of Science databases, adhering to "Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews" guidelines. Articles presenting 3D facial photographs in the diagnostic phase were considered.

RESULTS

A total of 79 articles were identified, of which 29 were selected for analysis.

CONCLUSION

The predominant use of automated systems like 3dMD and VECTRA M3 was noted. User positioning has highest agreement among authors. Noteworthy aspects include the importance of proper lighting, facial expression, and dental positioning, with observed discrepancies and inconsistencies among authors. Finally, the authors proposed a 3D image acquisition protocol based on this research findings.

Comparison of Effects between Total Maxillary Setback Osteotomy and Anterior Maxillary Segmental Osteotomy on Nasolabial Morphology

BACKGROUND

The authors aimed to compare the effects of total maxillary setback osteotomy (TMSO) and anterior maxillary segmental osteotomy (AMSO) on nasolabial morphology.

METHODS

This retrospective clinical trial enrolled 130 patients undergoing maxillary surgery using TMSO or AMSO. Ten nasolabial-related parameters and nasal airway volume were measured preoperatively and postoperatively. The soft-tissue digital model was reconstructed using Geomagic Studio and Dolphin image 11.0. Statistical analysis was performed using IBM SPSS Version 27.0.

RESULTS

A total of 75 patients underwent TMSO, and 55 underwent AMSO. Both techniques achieved optimal repositioning of the maxilla. Except for the dorsal nasal length, the dorsal nasal height, the length of the nasal columella, and the upper lip thickness, the remaining parameters were significantly different in the TMSO group. In the AMSO group, only the nasolabial angle, the alar base width, and the greatest alar width showed significant differences. There was a significant difference in the nasal airway volume for the TMSO group. The results of matching maps are consistent with the statistical results.

CONCLUSIONS

TMSO has a more significant impact on both nose and upper lip soft tissues, whereas AMSO has a more significant impact on the upper lip and less on the nasal soft tissue. There is a significant decrease in nasal airway volume after TMSO, whereas AMSO showed less decrease. This retrospective study is helpful for clinicians and patients to understand the different changes in nasolabial morphology caused by the two interventions, which is essential for effective intervention and physician-patient communication.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, III.

Analysis of select esthetic nasal parameters in virtually planned orthognathic patients

PURPOSE

Bony changes after orthognathic surgery are always followed by changes of the overlying soft tissues. Therefore, morphologic changes of the nose may be expected after procedures involving the maxilla. The purpose of this study was to evaluate the changes in the nasal region due to orthognathic surgery using computed tomography (CT) images of virtually planned patients.

METHODS

35 patients who underwent Le Fort I osteotomy, with or without bilateral sagittal split osteotomy, were included. 3D measurements on preoperative and postoperative images were performed and analyzed.

RESULTS

The results revealed that aesthetically acceptable results can be achieved by orthognathic surgery alone.

CONCLUSIONS

According to the results of this study, it can be concluded that it is best to reserve decisions on rhinoplasty to the post-orthognathic period.

The Vectra M3 3-dimensional digital stereophotogrammetry system: A reliable technique for detecting chin asymmetry

Purpose

The aim of this study was to evaluate the reliability of the Vectra M3 (3D Imaging System; Canfield Scientific, Parsippany, NJ, USA) in detecting chin asymmetry, and to assess whether the automatic markerless tracking function is reliable compared to manually plotting landmarks.

Materials and Methods

Twenty subjects (18 females and 2 males) with a mean age of 42.5±10.5 years were included. Three-dimensional image acquisition was carried out on all subjects with simulated chin deviation in 4 stages (1-4 mm). The images were analyzed by 2 independent observers through manually plotting landmarks and by Vectra software auto-tracking mode. Repeated-measures analysis of variance and the Tukey post-hoc test were performed to evaluate the differences in mean measurements between the 2 operators and the software for measuring chin deviation in 4 stages. The intraclass correlation coefficient (ICC) was calculated to estimate the intra- and inter-examiner reliability.

Results

No significant difference was found between the accuracy of manually plotting landmarks between observers 1 and 2 and the auto-tracking mode (P=0.783 and P=0.999, respectively). The mean difference in detecting the degree of deviation according to the stage was <0.5 mm for all landmarks.

Conclusion

The auto-tracking mode could be considered as reliable as manually plotted landmarks in detecting small chin deviations with the Vectra® M3. The effect on the soft tissue when constructing a known dental movement yielded a small overestimation of the soft tissue movement compared to the dental movement (mean value<0.5 mm), which can be considered clinically non-significant.

Analysis of Gull in Flight Appearance and Related Parameters Following Le Fort I Osteotomy

ABSTRACT

The present study aimed to investigate how "Gull in Flight" appearance and alar-columellar relationship change following maxillary surgery. Thirty-three patients who underwent Le Fort I osteotomy with or without mandibular osteotomy were included in this retrospective study. Measurements which were angle of columella triangle, alar-rim angle, columella lobular angle, and distance of points forming "Gull in Flight" appearance were evaluated on pre and postoperative frontal and lateral photos of patients. Data was submitted to statistical analysis and significance level was determined as 0.05. Following Le Fort I surgery, distance of points forming "Gull in Flight" appearance with respect to canthus was decreased significantly (P < 0.05). Positions of these points to each other were not changed (P > 0.05). Every 1 mm maxillary impaction led to 0.58 mm reduction in y3 (the distance from the point that illustrates Gull's body) (P = 0.032). There was a decrease in angle of columella triangle, alar-rim angle and increase in columella lobular angle. However, these changes were not found significant (P > 0.05). Angle of columella triangle was increased 2.51 degree for every 1 mm maxillary advancement (P = 0.028). In conclusion, maxillary surgery had an impact on nasal region from frontal view. However, "Gull in Flight" appearance which is one of the aesthetic parameters in nose was not changed following maxillary surgery.

Three-dimensional nasolabial changes after maxillary advancement osteotomy in class III individuals: a systematic review and meta-analysis

Background Class III malocclusions with maxillary retrognathia are commonly treated with single jaw Le Fort I maxillary advancement. The three-dimensional (3D) effects of surgery on the nasolabial region varies among the clinical studies. Quantifying these changes is of great importance for surgical planning and obtaining valid consent. Objectives To investigate the 3D relationship between soft tissue and skeletal changes secondary to Le Fort I maxillary advancement surgery in skeletal class III patients.Search methods Comprehensive search of multiple electronic databases supplemented by a manual and grey literature search were undertaken from inception to 9 June 2020.Selection criteria Studies that evaluated the 3D soft tissue changes of patients before and after maxillary advancement surgery alone.Data collection and analysis Study selection, data extraction and risk of bias assessment were performed independently by two reviewers, with disputes resolved by a third reviewer. A quantitative synthesis of the data was pre-planned for pooling similar outcome measures.Results Four studies were included in the final review and meta-analysis, with a total of 105 patients (mean age 16.7 + 33.9 years). The mean maxillary advancement of the included studies was 5.58 mm (95% CI 5.20-5.96). The sagittal effects of surgery on nose tip projection and prominence were insignificant (P >0.05, two studies); however, subnasal projection (MD 1.7 mm, two studies) and upper lip projection (MD 2.90 mm, four studies) increased significantly in a forward direction after surgery (P <0.05). Le Fort I osteotomy widens the upper philtrum width (MD 0.84 mm, two studies) (P <0.05). Inconsistencies among the included studies were identified; therefore, the results should be interpreted with caution.Conclusions There is weak evidence based on quantitative assessments that Le Fort I maxillary advancement significantly affects the nasolabial soft tissue envelope mainly in a sagittal dimension. These changes are concentrated around the central zone of the nasolabial region. Future prospective studies on maxillary advancement osteotomy with a standardised method of assessment, taking into consideration the confounding factors, are required.

Evaluation of the Therapeutic Effect of Bi-Maxillary Osteotomy Using the Stress Distribution on the Temporomandibular Joint When Doing Anterior Teeth Occlusion

The purpose of this study was to investigate how sagittal split ramus osteotomy (SSRO) and Le Fort 1 osteotomy affected the stress distribution of the temporomandibular joint (TMJ) during an anterior teeth bite using the three-dimensional (3D) finite element (FE) method. Fourteen orthognathic surgery patients were examined with mandibular prognathism, facial asymmetry, and mandibular retraction. They underwent Le Fort 1 osteotomy in conjunction with SSRO. In addition, ten asymptomatic subjects were recruited as the control group. The 3D models of the mandible, disc, and maxilla were reconstructed according to cone-beam computed tomography (CBCT). Contact was used to simulate the interaction of the disc-condyle, disc-temporal bone, and upper-lower dentition. Muscle forces and boundary conditions corresponding to the anterior occlusions were applied on the models. The stresses on the articular disc and condyle in the pre-operative group were significantly higher than normal. The contact stress and minimum principal stress in TMJ for patients with temporomandibular disorder (TMD) were abnormally higher. The peak stresses of the TMJ of the patients under anterior occlusions decreased after bimaxillary osteotomy. No postoperative TMD symptoms were found. Maxillofacial deformity led to excessive stress on the TMJ. Bimaxillary osteotomy can partially improve the stress distributions of the TMJ and relieve the symptoms of TMD.

Patient- and 3D morphometry-based nose outcomes after skeletofacial reconstruction

Patient satisfaction with the shape and appearance of their nose after orthognathic surgery-based skeletofacial reconstruction is an important, but often overlooked, outcome. We assessed the nose-related outcomes through a recently developed patient-reported outcome instrument and a widely adopted 3D computer-based objective outcome instrument, to verify any correlation in the results produced by these tools. We collected FACE-Q nose appearance reports (2 scales) and 3D nasal morphometry (10 parameters) from patients with class III skeletal pattern and congenital cleft lip palate deformity (n = 23) or developmental dentofacial deformity (n = 23) after (>12 months) skeletofacial reconstruction. The cleft and dentofacial cohorts demonstrated significantly (p < 0.001) poorer satisfaction scores with regard to the FACE-Q nostrils scale than the normal age-, gender-, and ethnicity-matched subjects (n = 107), without any significant difference in FACE-Q nose scale. The cleft cohort had significantly (p < 0.001) smaller nasal length, nasal tip projection, and columellar angle and greater nasal protrusion, alar width, and columellar-labial angle values than the dentofacial and normal cohorts; however, there were no significant differences between the dentofacial versus normal cohorts. The FACE-Q nose and nostrils scales were significantly (p < 0.001; r = -0.26-0.27) correlated to the results of the 3D morphometric analysis, with regard to nasal length, alar width, columella angle, and columellar-labial angle parameters. This study revealed differences in satisfaction with the appearance of the nose according to the type of underlying deformity, and demonstrated a significant correlation (low correlation coefficients) between the patient-reports and 3D image-based outcome measure tools, which has implications for multidisciplinary-centered research, auditing, and clinical care.