Accuracy of edentulous full-arch implant impression: An in vitro comparison between conventional impression, intraoral scan with and without splinting, and photogrammetry.

OBJECTIVES: The purpose of this in vitro study was to compare the trueness and precision of complete arch implant impressions using conventional impression, intraoral scanning with and without splinting, and stereophotogrammetry. MATERIALS AND METHODS: An edentulous model with six implants was used in this study. Four implant impression techniques were compared: the conventional impression (CI), intraoral scanning (IOS) without splinting, intraoral scanning with splinting (MIOS), and stereophotogrammetry (SPG). An industrial blue light scanner was used to generate the baseline scan from the model. The CI was captured with a laboratory scanner. The reference best-fit method was then applied in the computer-aided design (CAD) software to compute the three-dimensional, angular, and linear discrepancies among the four impression techniques. The root mean square (RMS) 3D discrepancies in trueness and precision between the four impression groups were analyzed with a Kruskal-Wallis test. Trueness and precision between single analogs were assessed using generalized estimating equations. RESULTS: Significant differences in the overall trueness (p = .017) and precision (p < .001) were observed across four impression groups. The SPG group exhibited significantly smaller RMS 3D deviations than the CI, IOS, and MIOS groups (p < .05), with no significant difference detected among the latter three groups (p > .05). CONCLUSIONS: Stereophotogrammetry showed superior trueness and precision, meeting misfit thresholds for implant-supported complete arch prostheses. Intraoral scanning, while accurate like conventional impressions, exhibited cross-arch angular and linear deviations. Adding a splint to the scan body did not improve intraoral scanning accuracy.

Three-Dimensional Anthropometric Facial Analysis and Fitting Discrepancies Between Stereophotogrammetry and CT.

BACKGROUND: The reliability and repeatability of stereophotogrammetry and CT in 3-dimensional anthropometric facial analysis were investigated in this study, which also explored the clinical application of supine CT. METHOD: In this study, 3D CT and 3dMD stereophotogrammetry were used on 20 healthy volunteers. The fitting distance between stereophotogrammetry and CT scans at landmark points was measured, along with facial feature measurements (Al-Al) face width (Go-Go, Zy-Zy, Ex-Ex), and hemi-face height (Sn-Gn). The intraclass correlation coefficient (ICC) was employed to assess interrater agreement and to verify the reliability of the measurement methods. Paired t -analysis was utilized for analyzing intramethod displacement. RESULTS: The alare, nasion, and pronasale points were found to be minimally influenced by different positions and are more recommended as landmark points for registration. CT demonstrated good interrater reliability on all indicators. In stereophotogrammetry, measurements for Go-Go and Zy-Zy displayed an interclass correlation coefficient (ICC) of less than 0.75. Significant differences between the 2 methods were observed for En-En, Ex-Ex, and Go-Go ( P < 0.05). Specifically, CT analysis for Go-Go showed a measurement 2.34 mm larger than that obtained with the 3dMD method. CONCLUSION: Both CT and stereophotogrammetry were found to be reliable methods for evaluating facial soft tissue. It is speculated that Go-Go measurement is primarily influenced by factors such as different positions, facial expressions, and gravity. These variables should be carefully considered during the evaluation of the mandibular angle region.

Accuracy of traditional open-tray impression, stereophotogrammetry, and intraoral scanning with prefabricated aids for implant-supported complete arch prostheses with different implant distributions: An in vitro study.

STATEMENT OF PROBLEM: Conventional impression techniques for complete arch implant-supported fixed dental prostheses (CIFDPs) are technique sensitive. Stereophotogrammetry (SPG) and intraoral scanning (IOS) may offer alternatives to conventional impression making. PURPOSE: The purpose of this in vitro study was to assess the accuracy and passive fit of IOS with prefabricated aids, SPG, and open tray impression (OI) for CIFDPs with different implant distributions. MATERIAL AND METHODS: Three definitive casts with 4 parallel implants (4-PARA), 4 inclined implants (4-INCL), and 6 parallel implants (6-PARA) were fabricated. Three recording techniques were tested: IOS with prefabricated aids, SPG, and OI. The best and the worst scans were selected to fabricate 18 milled aluminum alloy frameworks. The trueness and precision of distance deviation (∆td and ∆pd), angular deviation (∆tθand ∆pθ), root mean square errors (∆tRMS for ∆pRMS), and passive fit score of frameworks were recorded. Two-way ANOVA was applied. RESULTS: SPG showed the best trueness and precision (95%CI of ∆td/∆tθ/∆tRMS, 31 to 39 µm, 0.22 to 0.28 degrees, 20 to 23 µm; 95%CI of ∆pd/∆pθ/∆pRMS, 9 to 11 µm, 0.06 to 0.08 degrees, 8 to 10 µm), followed by OI (61 to 83 µm, 0.33 to 0.48 degrees, 28 to 48 µm; 66 to 81 µm, 0.29 to 0.38 degrees, 32 to 41 µm) and IOS (143 to 193 µm, 0.37 to 0.50 degrees, 81 to 96 µm; 89 to 111 µm, 0.27 to 0.31 degrees, 51 to 62 µm). Tilted implants were associated with increased distance deviation. Increased implant number was associated with improved recording precision. The passive fit of frameworks was negatively correlated with the RMS error, and the correlation coefficient was -0.65 (P=.003). CONCLUSIONS: SPG had the best accuracy. Implant distributions affected implant precision. The RMS error can be used to evaluate the passive fit of frameworks.

Fabrication of three-dimensionally printed polylactic acid nasal stent prosthesis for postnasal reconstruction using extraoral scanning and photogrammetry techniques: A report on two patients.

Severe and combined nasal defects associated with trauma or neoplasm excision can cause significant functional and esthetic problems. To avoid nasal synechia following reconstructive surgeries, a nasal stent prosthesis is required to act as an internal scaffold to support the graft and residual tissues. The purpose of the stent is to maintain internal airway patency and to prevent collapse and contracture of the donor tissues. A conventional nasal stent prosthesis has disadvantages, including the difficulty in maintaining adequate thickness and internal patency during fabrication. Hence, this clinical report introduces the fabrication technique for 3-dimensionally printed polylactic acid nasal stent prostheses using extraoral scanning and photogrammetry methods.

Accuracy of implant abutment level digital impressions using stereophotogrammetry in edentulous jaws: an in vitro pilot study.

BACKGROUND: In edentulous jaws, factors such as the number of implants, cross-arch distribution, and the angle among implants may affect the accuracy of the implant impression. This study explored factors influencing the accuracy of implant abutment-level digital impressions using stereophotogrammetry in edentulous jaws. METHODS: Two standard all-on-4 and all-on-6 models of edentulous jaws were constructed in vitro. In the stereophotogrammetry group (PG), the implant digital impression was made using stereophotogrammetry and saved as an STL file. In the conventional group (CNV), the impression was made using the open-tray splint impression technique. An electronic and optical 3D measuring instrument was used to scan the standard model and the conventional plaster model to obtain STL files. Using 3D data processing software (GOM Inspect Pro, Zeiss), the distance and angle between the abutments in the CNV impression and the PG impression were measured and compared with the data from the standard model. RESULTS: The distance deviation in the PG and the CNV was 145 ± 196 µm and 96 ± 150 µm, respectively, with a significant difference (P < 0.001). The angle deviation in the PG and the CNV was 0.82 ± 0.88° and 0.74 ± 0.62°, respectively, with no significant difference (P = 0.267). In the PG, the distance deviation was negatively correlated with the distance between implants (r = -0.145, P = 0.028) and positively correlated with the angle of implants (r = 0.205, P = 0.002). The angle deviation was negatively correlated with the distance between implants (r = -0.198, P = 0.003) and positively correlated with the angle of implants (r = 0.172, P = 0.009). In the CNV, the effect of inter-implant distance on impression accuracy was also shown by Spearman correlation analysis: r = 0.347 (P < 0.001) for distance deviation and r = -0.012 (P = 0.859) for angle deviation. The effect of inter-implant angulation on impression accuracy deviation was r = -0.026 (P = 0.698) for distance deviation and r = 0.056 (P = 0.399) for angle deviation. CONCLUSIONS: The CNV method is closer to the real value of the original model. The distance between implants and the distribution angle had a weak correlation with the accuracy of digital impressions but no significant correlation with the accuracy of traditional impressions.

Measuring asymmetry in facial morphea via 3-dimensional stereophotogrammetry.

BACKGROUND: Objectively determining tissue loss in craniofacial morphea is challenging. However, 3-dimensional (3D) stereophotogrammetry is a noninvasive modality that may be a useful adjunct. OBJECTIVE: To prospectively evaluate 3D stereophotogrammetry in the assessment of craniofacial linear morphea. METHODS: Participants underwent clinical, quality-of-life, and 3D-stereophotogrammetry assessments. Traditional photographs and 3D-stereophotogrammetry images were rated as mild, moderate, or severe by 2 experts and 2 nonexperts. In addition, interrater and intrarater reliability (on delayed rescoring) were calculated. RESULTS: Of 23 patients with craniofacial morphea, 3D stereophotogrammetry detected pathologic asymmetry in 14 (20.6%) patients. Providers rated patients as more severely affected when using 3D stereophotogrammetry versus when using traditional photographs (19% severe on 3D stereophotogrammetry vs 0% severe on traditional photographs, P = .004). Qualitative ratings of both traditional and 3D images showed high inter- and intrarater reliability between experts and nonexperts alike. Physicians' Global Assessment of Damage scores correlated with mouth asymmetry (P = .0021), cheek asymmetry (P = .04), and 3D-stereophotogrammetry ratings (median, mild: 27.5 vs moderate: 46.5 vs severe: 64, P = .0152). Lower face asymmetry correlated with worse quality-of-life scores (P = .013). LIMITATIONS: Small sample size and cross-sectional design. CONCLUSION: 3D stereophotogrammetry can reliably detect and quantify asymmetry in craniofacial morphea with greater sensitivity than that observed with traditional assessment alone. 3D stereophotogrammetry may be a useful adjunct to clinical examination.

Comparison of Manual (2D) and Digital (3D) Methods in the Assessment of Simulated Facial Edema.

BACKGROUND: An edema assessment following dental surgeries is essential to improving the dental surgeon's technique and, consequentially, patient comfort. PURPOSE: Two-dimensional (2D) methods are limited in analyzing 3-dimensional (3D) surfaces. Currently, 3D methods are used to investigate postoperative swelling. However, there are no studies that directly compare 2D and 3D methods. The goal of this study is to directly compare 2D and 3D methods used in the assessment of postoperative edema. STUDY DESIGN AND SAMPLE: The investigators implemented a prospective, cross-sectional study with each subject serving as its own control. The sample was composed of dental student volunteers without facial deformities. PREDICTOR VARIABLE: The predictor variable is the method used to measure edema. After simulating edema, manual (2D) and digital (3D) techniques were used to measure edema. The manual method used direct facial perimeter measurements. The two digital methods were photogrammetry using a smartphone (iPhone 11, Apple Inc, Cupertino, California), and facial scanning with a smartphone application (Bellus3D FaceApp, Bellus3D Inc, Campbell, California) [3D measurements] MAIN OUTCOME VARIABLE: The coefficient of variation (CV) (CV = standard deviation /mean) was used to assess homogeneity of edema measurements. ANALYSIS: The Shapiro-Wilk and equal variance tests were applied to assess data homogeneity. Next, one-way analysis of variance was performed, followed by a correlation analysis. Finally, the data were submitted to Tukey's test. The statistical significance threshold was set at 5% (P < .05). RESULTS: The sample was composed of 20 subjects aged 18-38 years. The CV showed higher values using the manual (2D) method (47%; 4.88% ± 2.99), compared with the photogrammetry method (18%; 8.55 mm ± 1.52) and the smartphone application (21%; 8.97 mm ± 1.93). A statistically significant difference was observed between the manual method values and those of the other two groups (P < .001). There was no difference between the facial scanning and photogrammetry groups (3D methods) (P = .778) CONCLUSION AND RELEVANCE: Both digital measuring methods (3D) demonstrated greater homogeneity than the manual method in analyzing facial distortions caused by the same swelling simulation. Therefore, it can be affirmed that digital methods may be more reliable that manual methods for assessing facial edema.

Three-dimensional evaluation of social smile asymmetry in patients with unilateral impacted maxillary canine: a 3D stereophotogrammetry study.

OBJECTIVE: This study aimed to evaluate social smile asymmetry in patients with unilateral impacted maxillary canine on 3D stereophotogrammetric images. MATERIAL AND METHODS: The 3D social smile images of participants with unilateral impacted maxillary canine (n:20) and without impaction as a control group (n:20) were included. The images were recorded with a hand-held 3D stereophotogrammetry device (Fuel3D® Scanify®) and Geomagic Essentials 2 reverse engineering software were used for analyses. After the orientation process of the 3D records, the tissues around the smile area were divided into five morphological regions: cheek, upper lip lateral and medial, and lower lip lateral and medial. The deviation margins in the negative and positive directions for the 95% mesh rate and the total percentages of meshes between - 0.5- and + 0.5-mm deviations were calculated. ICC, paired samples t test, independent samples t test, and the Mann-Whitney U test were used for statistical analyses. RESULTS: In individuals with impacted canine, the amount of maximum positive deviation in the upper lip medial was 5.64 mm ± 1.46 and maximum negative deviation was - 4.6 mm ± 1.17. In the control group, mean of deviation limits for all parameters was less than 1.19 mm ± 2.62, while in individuals with unilateral impacted maxillary canine, the maximum value was 8.34 mm ± 2.23. The mesh percentage between - 0.5 and 0.5-mm deviations was over 95% in all morphological areas in the control group, while in the impacted canine group, the number of meshes within the specified deviation limits was less than 95%. CONCLUSION: Individuals with unilateral impacted maxillary canine exhibit greater asymmetry in social smile compared to the control group, with the asymmetry being most prominent near the corners of the mouth and cheeks. CLINICAL RELEVANCE: Amount of asymmetry was higher in impaction group compared to the control group in social smile. The quantification of a possible smile asymmetry due to the impacted canine is crucial for the diagnosis and treatment planning of orthodontic and/or orthognathic cases for ideal aesthetic results. Hence, smile asymmetry should not be overlooked and should be considered in diagnosis and treatment planning.

What is the impact of miniscrew-assisted rapid palatal expansion on the midfacial soft tissues? A prospective three-dimensional stereophotogrammetry study.

OBJECTIVES: To evaluate the midfacial soft tissue changes of the face in patients treated with miniscrew-assisted rapid palatal expansion (MARPE). MATERIALS AND METHODS: 3D facial images and intra-oral scans (IOS) were obtained before expansion (T0), immediately after completion of expansion (T1), and 1 year after expansion (T2). The 3D images were superimposed and two 3D distance maps were generated to measure the midfacial soft tissue changes: immediate effects between timepoints T0 and T1 and overall effects between T0 and T2. Changes of the alar width were also measured and dental expansion was measured as the interpremolar width (IPW) on IOS. RESULTS: Twenty-nine patients (22 women, 7 men, mean age 25.9 years) were enrolled. The soft tissue in the regions of the nose, left of philtrum, right of philtrum, and upper lip tubercle demonstrated a statistically significant anterior movement of 0.30 mm, 0.93 mm, 0.74 mm, and 0.81 mm, respectively (p < 0.01) immediately after expansion (T0-T1). These changes persisted as an overall effect (T0-T2). The alar width initially increased by 1.59 mm, and then decreased by 0.08 mm after 1 year, but this effect was not significant. The IPW increased by 4.58 mm and remained stable 1 year later. There was no significant correlation between the increase in IPW and alar width (r = 0.35, p = 0.06). CONCLUSIONS: Our findings indicate that MARPE results in significant but small changes of the soft tissue in the peri-oral and nasal regions. However, the clinical importance of these findings is limited. CLINICAL RELEVANCE: MARPE is an effective treatment modality to expand the maxilla, incurring only minimal and clinically insignificant changes to the midfacial soft tissues.

How Do the Faces of Kyrgyz Beauties Look? A Photogrammetric Analysis of Beauty Pageant Winners.

The aim of this study was to assess how the eyes of Kyrgyz beauties look through an anthropometric analysis of beauty pageant winners. Eleven winners of the Miss Kyrgyzstan contest (2011-2021) were included. Ten other beauty contest winners were added, resulting in a total of 21 beauties who were included. The horizontal corneal diameter, which is 11.75 mm, was used as a standard distance. Other distances were calculated in millimeters based on the proportions of the pixels measured. Twenty-six distances (face: 10, eyebrows: 2, eyes: 4, nose: 4, lips: 4, and chin: 2) and 9 angles (forehead-brow, cantal tilt, 5 face angles, the mandible angle, and the chin angle) were measured. Thereafter, 16 indices (forehead: 1, eyes: 5, nose: 4, lips and chin: 3, and contours 3) were calculated. The forehead-brow angle was 82.2±7.2 degrees. The canthal tilt was 9.0±2.0 degrees. The overall face angles 1 and 2 were 108.6±4.1 degrees and 69.6±2.3 degrees, respectively. The midface angles 1 and 2 were 129.9±3.8 degrees and 125.1±3.9 degrees, respectively. The lower face angle was 139.6±4.1 degrees. The mandible angle and chin angle were 136.9±4.0 degrees and 106.0±4.0 degrees, respectively. The ratio of forehead height to total face height was 0.33±0.03. The ratio of nose height to total face height was 0.25±0.02. The lower face width/face width ratio was 0.82±0.05. The ratio of face width to total face height was 0.72±0.03. The ratio of midface height to total face height was 0.34±0.02. The data from this study might serve as the recommended esthetic proportions for performing plastic surgical procedures.

Photogrammetry technology in implant dentistry: A systematic review.

STATEMENT OF PROBLEM: Photogrammetry technology may be useful in implant dentistry, but a systematic review is lacking and is indicated before routine use in clinical practice. PURPOSE: The purpose of this systematic review was to assess the role of the photogrammetry technology used in implant dentistry and determine its validity as an accurate tool with clinical applications. MATERIAL AND METHODS: Four major databases, PubMed MEDLINE, Google Scholar, Scopus, and Web of Science, were selected to retrieve articles published from January 2011 to February 2021 based on custom criteria. The search was augmented by a manual search. After screening of the collected articles, data, including study design and setting, type of application, digitizer used, reference body, method of evaluation, and overall outcomes, were extracted. RESULTS: Twenty articles were included based on the selection criteria. Most of the articles confirmed that the use of photogrammetry was promising as an implant coordinate transfer system. However, few articles showed its use for 3-dimensional scanning, which might require more development. CONCLUSIONS: The initial reports of using photogrammetry technology considered this method as a valid and reliable clinical tool in implant dentistry. More studies to develop the photogrammetry technology and to assess the results with evidence-based research are recommended to enhance its application in different clinical situations.

Trueness and precision of complete-arch photogrammetry implant scanning assessed with a coordinate-measuring machine.

STATEMENT OF PROBLEM: Photogrammetry technology has been used for the digitalization of multiple dental implants, but its trueness and precision remain uncertain. PURPOSE: The purpose of this in vitro investigation was to compare the accuracy (trueness and precision) of multisite implant recordings between the conventional method and a photogrammetry dental system. MATERIAL AND METHODS: A definitive cast of an edentulous maxilla with 6 implant abutment replicas was tested. Two different recording methods were compared, the conventional technique and a photogrammetry digital scan (n=10). For the conventional group, the impression copings were splinted to an additively manufactured cobalt-chromium metal with autopolymerizing acrylic resin, followed by recording the maxillary edentulous arch with an elastomeric impression using an additively manufactured open custom tray. For the photogrammetry group, a scan body was placed on each implant abutment replica, followed by the photogrammetry digital scan. A coordinate-measuring machine was selected to assess the linear, angular, and 3-dimensional discrepancies between the implant abutment replica positions of the reference cast and the specimens by using a computer-aided design program. The Shapiro-Wilk test showed that the data were not normally distributed. The Mann-Whitney U test was used to analyze the data (α=.05). RESULTS: The conventional group obtained an overall accuracy (trueness ±precision) value of 18.40 ±6.81 µm, whereas the photogrammetry group showed an overall scanning accuracy value of 20.15 ±25.41 µm. Significant differences on the discrepancies on the x axis (U=1380.00, P=.027), z axis (U=601.00, P<.001), XZ angle (U=869.00, P<.001), and YZ angle (U=788.00, P<.001) were observed when the measurements of the 2 groups were compared. Furthermore, significant 3-dimensional discrepancy for implant 1 (U=0.00, P<.001), implant 2 (U=0.00, P<.001), implant 3 (U=6.00, P<.001), and implant 6 (U=9.00, P<.001) were computed between the groups. CONCLUSIONS: The conventional method obtained statistically significant higher overall accuracy values compared with the photogrammetry system tested, with a trueness difference of 1.8 µm and a precision difference of 18.6 µm between the systems. The conventional method transferred the implant abutment positions with a uniform 3-dimensional discrepancy, but the photogrammetry system obtained an uneven overall discrepancy among the implant abutment positions.

Arch Symmetry in Patients Without and With Cleft Lip and Palate After Orthodontic/Rehabilitative Treatment-A Stereophotogrammetry Study.

To evaluate and compare the dental arch symmetry of individuals with and without cleft lip and palate after orthodontic/rehabilitation treatment.Cross-sectional study.Tertiary cleft center in Brazil.Fifty-five participants aged between 18 and 30 years were divided into 3 groups according to treatment. Patients that received either a fixed partial denture (FPD) or implant-supported crown (ISC) in the cleft area or only orthodontic treatment, noncleft patients (NC).An analysis was performed using digitized dental casts scanned by laser and software. The following linear measurements were evaluated: incisor-canine; canine-molar; incisor-molar; surface and volume of the palatal region.Three-way ANOVA was used to compare the study factors: group (FPD/ISC/NC) and side (right/left) followed by the Tukey test to verify their interaction (α = .05).The results showed statistically significant differences among groups for the maxillary linear measurements canine-molar and incisor-molar, but not for incisor-canine. No statistically significant differences were found regarding the side for the maxillary measurements, while the factor interaction showed similarity only for incisor-canine. The mandibular measurements showed no statistical differences among groups, sides, or factor interactions. In surface and volume, all values in patients with cleft presented lesser than in without cleft patients.Regardless of the rehabilitation, arch symmetry can be achieved in the incisor-canine dimension in the cleft area.

Accuracy of photogrammetric imaging versus conventional impressions for complete arch implant-supported fixed dental prostheses: A comparative clinical study.

STATEMENT OF PROBLEM: Clinical studies on the accuracy of the photogrammetric imaging technique for complete arch implant-supported fixed dental prostheses are lacking. PURPOSE: The purpose of this clinical study was to evaluate the accuracy (trueness) of photogrammetric imaging for complete arch implant-supported prostheses by comparing photogrammetric imaging with verified conventional splinted impressions. MATERIAL AND METHODS: Completely edentulous arches with at least 4 implants were included. Both photogrammetric imaging and conventional splinted impressions were performed in each jaw. The conventional casts were verified and scanned by using a laboratory scanner as the control. The distances and angulations between different implants (interimplant distances and interimplant angulations) were measured in all photogrammetric and conventional standard tessellation language (STL) files by using a reverse-engineering software program. The distance deviations between the photogrammetric and conventional impressions of the same participant were calculated as the primary outcome, and the angular deviations were obtained as the secondary outcome with descriptive analyses. The comparison between distance deviations and the clinically acceptable level of deviations (150 µm) was conducted by using the 1-sample t test. The effect of interimplant distances, interimplant angulations, and jaw (maxilla or mandible) on deviations was analyzed by using the Spearman correlation analysis, Kruskal-Wallis test, or Student t test, depending on the type of data (α=0.05 for all tests). RESULTS: Fourteen edentulous jaws were included. The overall distance deviation of photogrammetric imaging was 70 ±57 µm, significantly lower than the clinically acceptable level of misfit (150 µm; P<.001). The overall angular deviation was 0.432 ±0.348 degrees. The distance deviations were correlated with interimplant distances with a correlation coefficient (r) of 0.371 (P=.002). Interimplant angulation was not correlated with distance or angular deviations (P=.914, P=.914). Jaw was not correlated with distance or angular deviations either (P=.190, P=.209). CONCLUSIONS: The accuracy (trueness) of photogrammetric imaging of complete arch implant-supported prostheses was within a clinically acceptable range of errors. Distance deviations increased with greater interimplant distances. Interimplant angulations and jaw (maxilla or mandible) had no significant effect on the accuracy of photogrammetric imaging.

Volumetric Comparison Between CT Scans and Smartphone-Based Photogrammetry in Patients Undergoing Chin Augmentation With Autologous Fat Graft.

BACKGROUND: The most accurate methods for assessing fat grafted volume, such as computed tomography (CT) scan and magnetic resonance imaging, use 3-dimensional (3D) evaluation of the recipient area. Currently, other measurement techniques such as photogrammetry (compilation of photos) are employed. OBJECTIVES: The aim of the present study was to compare 3D images obtained by CT scan with those obtained by photogrammetry in patients undergoing autogenous fat grafting to the chin. METHODS: A prospective longitudinal study was undertaken to assess patients undergoing autologous fat grafting to the chin, capturing preoperative and postoperative (6 months) images with CT scan and photogrammetry. Captured images were submitted to 3D reconstruction with Blender image software. RESULTS: A total of 40 patients were submitted to surgery. Seventy-five percent were female. Median age and BMI were 26.5 years and 23.6 kg/m2, respectively. Median volume of fat grafted was 10 mL (interquartile range 8-12.25 mL). Results showed that the median preoperative volume measured by CT scan was larger than the photogrammetry measurement (12.48 mL vs 12.01 mL, respectively, P < .001). Likewise, a larger volume was measured by CT scan than by photogrammetry (15.54 mL vs 14.94 mL respectively, P < .001) 6 months postoperatively. However, there was no difference between CT scan and photogrammetry measurements of the change in volume from preoperatively to postoperatively (P = .89). CONCLUSIONS: There was no agreement between fat graft volume measurements obtained by 3D photogrammetry and CT scan techniques with regard to absolute values of fat graft volume measurements, however no difference was found between the 2 methods when comparing preoperative with postoperative fat graft volume variation.

Accuracy, scanning time, and patient satisfaction of stereophotogrammetry systems for acquiring 3D dental implant positions: A systematic review.

PURPOSE: To evaluate accuracy, scanning time, and patient satisfaction of photogrammetry (PG) systems for recording the 3D position of dental implants. MATERIAL AND METHODS: A literature search was completed in five databases: PubMed/Medline, Scopus, Embase, World of Science, and Cochrane. A manual search was also conducted. Studies reporting the use of commercially available PG systems were included. Two investigators evaluated the studies independently by applying the Joanna Briggs Institute critical appraisal. A third examiner was consulted to resolve any lack of consensus. RESULTS: A total of 14 articles were included: 3 in vivo, 6 in vitro, and 6 case report manuscripts. One clinical study evaluated trueness, another one tested precision, and the third one assessed impression time and patient and operator satisfaction. All the in vitro studies evaluated the trueness and precision of a PG system. Additionally, all the reviewed studies investigated completely edentulous conditions with multiple implants. The number of placed implants per arch among the reviewed clinical studies varied from 4 to 8 implants, while the number of implants placed on the reference casts included 4, 5, 6, or 8 implants. Not all the studies compared the accuracy of PG systems with conventional impression methods, using intraoral scanners as additional experimental groups. For the PIC system, trueness ranged from 10 to 49 µm and precision ranged from 5 to 65 µm. For the iCam4D system, trueness ranged from 24 to 77 µm and the precision value ranged from 2 to 203 µm. CONCLUSIONS: PG systems may provide a reliable alternative for acquiring the 3D position of dental implants. However, this conclusion should be interpreted carefully, as one study reported a mean precision value of one PG system higher than the clinically acceptable discrepancy. Lower scanning time and higher patient and operator satisfaction have been reported when compared with conventional techniques. Further studies are needed to increase the evidence regarding the accuracy, scanning time, and patient and operator satisfaction of the commercially available PG systems.

Photogrammetric Analysis of Nasal Dimensions in Indian Malaysian Adults.

ABSTRACT: In cosmetic rhinoplasty, knowledge of average nasal dimensions is important to create an aesthetic nose compatible with gender, ethnicity, and other facial feature. This study aimed to establish gender-specific nasal anthropometric data for Indian Malaysians (IMs) and to determine the interracial difference by comparing it with published data of three studies. Evaluation of nasal morphology was done on the standardized frontal, lateral, and basal photographs of 200 male and 200 female IM noses, aged 18-27 years. The measured variables were evaluated by using an independent t-test. Significant sexual dimorphism was found in 20 of 21 measurements, 5 nasal indices and 2 ratios. Significant racial features between IA and Saudi Arabian population were found in all 18 measurements and 5 nasal indexes. Seven of the 8 measurements and including the 2 ratios were significantly different between IM and Whites, but between IM and Chinese, all the 8 measurements and 2 ratios were significantly different. Compared to Saudi Arabian and Whites, IM had wider intercaantal distance, the nose was relatively shorter and wider, less projected radix, and prominent glabella with an increased backward slope of the forehead. Compared to the Chinese, the IM intercaantal distance and nose was narrower and the nasal root was slightly wider in the male group. The IM nasal tip was less projected and underrotated compared to all the 3 groups. In conclusion, the anthropometric analysis of IM noses revealed several unique nasal features, understanding these variations could be useful for the rhinoplasty surgeon to deliver ethnically congruent results.

Three-Dimensional Facial Anthropometric Analysis With and Without Landmark Labelling: Is There a Real Difference?

INTRODUCTION: The actual role of landmarks labeling before three-dimensional (3D) facial acquisition is still debated. In this study, several measurements were compared among textured labeled (TL), unlabeled (NL), and untextured (NTL) 3D facial models. MATERIALS AND METHODS: The face of 50 subjects was acquired through stereophotogrammetry. Landmark coordinates were extracted from TL, NL, and NTL facial models, and 33 linear and angular measurements were calculated, together with surface area and volume. Accuracy of measurements among TL, NL, and NTL models was assessed through calculation of relative technical error of measurement (rTEM). The intra- and inter-observer errors for each type of facial model were calculated. RESULTS: Intra- and inter-observer error of measurements increased passing from textured to NTL and NL 3D models. Average rTEMs between TL models, and NTL and NL models were 4.5 ±â€Š2.6% and 4.7 ±â€Š2.8%, respectively, almost all measurements being classified as "very good" or "good." Only for orbital height and its inclination, mandibular ramus length, nasal convexity, alar slope angle, and facial divergence, rTEM was classified as "moderate" or "poor." CONCLUSIONS: Accuracy and precision of measurements decrease when landmarks are not previously labeled; attention must be taken when measurements have a low magnitude or involve landmarks requiring palpation.

Facial Anthropometry Measurements Using Three-Dimensional Stereophotogrammetry Analysis Among Nigerians.

ABSTRACT: This study aimed to determine the normative facial anthropometry measurement among Nigerians using three-dimensional stereophotogrammetry analysis.This study was carried out in Lagos, Nigeria over a period of 3 years. The sample population was Nigerians of diverse ethnic groups, age 16 and above with no history of congenital or acquired craniofacial deformities.A total of 452 subjects participated in the study with 56.2% males and 43.8% females. Most of the participants were between the ages of 25 to 49 (54.4%), 40.7% were less than 25 years of age and only 4.4% were more than 50 years old. The mean body mass index (BMI) for males was 22.7 and 23.4 for females. Mean values of upper facial height, midfacial height, lower facial height, intercanthal distance, interpupillary distance, upper facial width, and lower facial width are 69.13 ±â€Š5.91, 49.89 ±â€Š3.56, 67.85 ±â€Š6.12, 35.19 ±â€Š3.20, 67.04 ±â€Š3.67, 139.43 ±â€Š7.11, and 124.29 ±â€Š9.72 mm, respectively. The upper facial height, commissure width, upper lip length, and lower jaw width were significantly affected by age, while the BMI of an individual was a determinant of the interpupillary distance, facial width, and lower jaw width.This study demonstrated that there was a statistically significant difference in the facial dimensions of males when compared to females across all ages among the study population. The authors also observed that age and BMI are significant predictors of variations in some of the measurements.

Anthropometric Periocular Soft Tissue Analysis From Preadolescence to Young Adulthood: Photogrammetric Measurements.

ABSTRACT: The periocular region has a central role in the prediction of ethnicity, understanding emotional expression, age, and sex. The aim of this study was to determine the sex-related growth changes in the periocular region of Turkish preadolescents, adolescents, and young adults. The study included a total of 234 individuals (preadolescents: 34 females and 40 males; adolescents: 40 females, 40 males, and young adults: 40 males and 40 females). A total of 7 periocular parameters (3 bilateral, 3 unilateral linear, and 1 angular measurement) were analyzed statistically to determine sex-related differences. The palpebral fissure and canthal indexes were also calculated. Of the 14 periocular measurements, 9 were found to be sexually dimorphic in certain age groups ( P < 0.05). Right-left palpebral fissure width and left palpebral fissure height were significantly different between young adult males and females ( P = 0.018, P = 0.013, and P = 0.027, respectively). A significant sexual dimorphism was observed for outercanthal distance and canthal index in 3 age groups ( P < 0.05). The data collected in this study may serve as a sex-dependent database source for the Turkish population during normal growth from preadolescence to young adulthood. The present study results would be useful for planning and designing aesthetic and post-traumatic surgical interventions in the periocular region as well as personal identification in this population.