Accuracy and repeatability of fetal facial measurements in 3D ultrasound: A longitudinal study

OBJECTIVE

Fetal face measurements in prenatal ultrasound can aid in identifying craniofacial abnormalities in the developing fetus. However, the accuracy and reliability of ultrasound measurements can be affected by factors such as fetal position, image quality, and the sonographer's expertise. This study assesses the accuracy and reliability of fetal facial measurements in prenatal ultrasound. Additionally, the temporal evolution of measurements is studied, comparing prenatal and postnatal measurements.

METHODS

Three different experts located up to 23 facial landmarks in 49 prenatal 3D ultrasound scans from normal Caucasian fetuses at weeks 20, 26, and 35 of gestation. Intra- and inter-observer variability was obtained. Postnatal facial measurements were also obtained at 15 days and 1 month postpartum.

RESULTS

Most facial landmarks exhibited low errors, with overall intra- and inter-observer errors of 1.01 mm and 1.60 mm, respectively. Landmarks on the nose were found to be the most reliable, while the most challenging ones were those located on the ears and eyes. Overall, scans obtained at 26 weeks of gestation presented the best trade-off between observer variability and landmark visibility. The temporal evolution of the measurements revealed that the lower face area had the highest rate of growth throughout the latest stages of pregnancy.

CONCLUSIONS

Craniofacial landmarks can be evaluated using 3D fetal ultrasound, especially those located on the nose, mouth, and chin. Despite its limitations, this study provides valuable insights into prenatal and postnatal biometric changes over time, which could aid in developing predictive models for postnatal measurements based on prenatal data.

Intra-rater and inter-rater reliability of 3D facial measurements

Three-dimensional (3D) body scanning technology has applications for obtaining anthropometric data in human-centered and product development fields. The reliability of 3D measurements gathered from 3D scans must be assessed to understand the degree to which this technology is appropriate for use in place of manual anthropometric methods. The intra- and inter-rater reliabilities of 3D facial measurements were assessed among four novice raters using 3D landmarking. Intraclass correlation coefficient (ICC) statistics were calculated for the 3D measurement data collected in three phases to assess baseline reliabilities and improvements in reliabilities as the result of additional training and experience. Based on the results of this study, the researchers found that the collection of 3D measurement data, by multiple raters and using 3D landmarking methods, yielded a high percentage of ICC statistics in the good to excellent (>0.75 ICC) reliability range. Rater training and experience were important considerations in improving intra- and inter-rater reliabilities.

"Utility of Smartphone-based Three-dimensional Surface Imaging for Digital Facial Anthropometry"

Background

The utilization of three-dimensional (3D) surface imaging for facial anthropometry is a significant asset for patients undergoing maxillofacial surgery. Notably, there have been recent advancements in smartphone technology that enable 3D surface imaging.In this study, anthropometric assessments of the face were performed using a smartphone and a sophisticated 3D surface imaging system.

Methods

30 healthy volunteers (15 females and 15 males) were included in the study. An iPhone 14 Pro (Apple Inc., USA) using the application 3D Scanner App (Laan Consulting Corp., USA) and the Vectra M5 (Canfield Scientific, USA) were employed to create 3D surface models. For each participant, 19 anthropometric measurements were conducted on the 3D surface models. Subsequently, the anthropometric measurements generated by the two approaches were compared. The statistical techniques employed included the paired t-test, paired Wilcoxon signed-rank test, Bland-Altman analysis, and calculation of the intraclass correlation coefficient (ICC).

Results

All measurements showed excellent agreement between smartphone-based and Vectra M5-based measurements (ICC between 0.85 and 0.97). Statistical analysis revealed no statistically significant differences in the central tendencies for 17 of the 19 linear measurements. Despite the excellent agreement found, Bland-Altman analysis revealed that the 95% limits of agreement between the two methods exceeded ±3 mm for the majority of measurements.

Conclusion

Digital facial anthropometry using smartphones can serve as a valuable supplementary tool for surgeons, enhancing their communication with patients. However, the proposed data suggest that digital facial anthropometry using smartphones may not yet be suitable for certain diagnostic purposes that require high accuracy.

Stature estimation from regression analysis of facial anthropometry in Indian population

Background:

Stature or body height is one of the most important and useful anthropometric parameters which determines the physical identity of an individual. As craniofacial structures have the advantage of being composed largely of hard tissue which is relatively indestructible, the careful study of these can enable reliable determination of stature of the person in life. Studies pertaining to stature estimation from facial measurements are limited in an Indian population. The present investigation attempts to estimate stature from anthropometric dimensions of face.

Materials and Methods:

The material for the present study comprises 361 Indian students (151 males and 210 females) in the age range of 21–45 years. Stature and six facial measurements were taken on each participant following standard methods and techniques. Karl Pearson's correlation coefficient and linear regression were done to estimate stature.

Results:

The results indicate that facial measurements are strongly and positively correlated (P < 0.001) with stature. The accuracy of the computed equations was further tested on 50 randomly selected study participants of each group, which shows close approximation of actual and estimated stature.

Conclusion:

Within the limits of this study, we conclude that facial dimensions can be used as a supplementary approach for the estimation of stature but with caution, as these are population-specific approach.

Reliability of Nasofacial Analysis Using Rhinobase® Software

OBJECTIVE

Rhinoplasty is a constant challenge for the surgeon, where the correct evaluation of facial aesthetic parameters allows harmonic changes appropriate for each patient. The aim of this study was to compare the preoperative and postoperative results of nasofacial analysis, performed by Rhinobase® software (indirect anthropometry) compared with direct anthropometry (caliper), in patients undergoing aesthetic rhinoplasty.

METHODS

The authors assessed the reliability of using Rhinobase® software for measuring nasofacial characteristics in 20 individuals (18 F, 2 M). In each patient, the nasofacial analysis was performed before and after surgery. Two raters performed indirect anthropometry on each image on two separate occasions.

RESULTS

Intrarater and interrater reliability for most indirect anthropometric measurements had intraclass correlation coefficients greater than 0.8. Regarding intermethod reliability, Pearson correlation coefficients ranged from 0.6 to 0.9 for most measurements. The highest correlation was found in interalar width, chin vertical, and lower facial height. The Cronbach's α coefficient calculated for all measurements was 0.8.

CONCLUSIONS

The Rhinobase® software is an easy and safe method for facial analysis. This study provides evidence of high reliability for several nasofacial measurements. The nasofacial analysis allows an accurate preoperative evaluation, surgical planning, and analysis of outcomes in rhinoplasty and may be a useful tool for both novice and experienced surgeons.

LEVEL OF EVIDENCE IV

This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266.

Morphological analysis of the lip and nose following cleft lip repair with simultaneous partial primary rhinoplasty: A prospective study over 4 years

INTRODUCTION

Facial clefts involve complex abnormalities. The therapy is elaborate, and a critical evaluation of therapeutic outcome is required. Our study analyzed the lip and nose deformities associated with unilateral clefts in a prospective longitudinal study.

MATERIAL AND METHODS

A total of 33 patients with a cleft lip or cleft lip and alveolus (UCL) and 46 with a cleft lip and palate (UCLP) were treated using a similar concept. Standardized photographs were taken preoperatively (age 0.4-0.52 years) and again aged 4.04-4.59 years. Anthropometric analyses were performed and compared with age-matched normal values.

RESULTS

Nostril width (UCL = 1.01, UCLP = 1.03) and nostril floor width (UCL = 1.02, UCLP = 1.04) were almost symmetric. Nasal tip angles were normalized by surgery. Upper labial height improved, but remained slightly reduced (-4% to -6%). Upper vermillion length was increased (15-17%), and vermillion width was reduced (-12% to -13%) postoperatively. A significantly flatter nostril axis inclination persisted, especially on the affected side (UCL: 37.5°; UCLP: 38.5°), when compared with normal values (53.8°).

CONCLUSION

Most cleft irregularities were almost eliminated by therapy; however, the outcome is still not satisfactory for some parameters. The rehabilitation of patients with clefts remains a considerable surgical challenge. Facial anthropometric assessment must play an important role in order to detect and overcome therapeutic shortcomings.