# Evaluation of the reproducibility of facial profile photographic records taken in two different head positions

## TL;DR

This study assessed how consistently professionals can take facial profile photos in two head positions, finding that both methods are reliable when done by trained individuals.

## Contribution

The study evaluates reproducibility of facial profile photography in two head positions using multiple examiners.

## Key findings

- NHP and OP showed good inter-examiner reliability with ICC values above 0.7.
- Only one examiner showed moderate intra-examiner reliability in both positions.
- Bland-Altman analysis confirmed agreement between NHP and OP methods across examiners.

## Abstract

This study aimed to evaluate the intra- and inter-examiner reproducibility of photographic records of the facial profile in Natural Head Position (NHP) and Oriented Position (OP) taken by four examiners (two orthodontists, one oral and maxillofacial surgeon, and one photography technician).

Each professional captured two lateral photographs of 25 individuals during the first (T1) and second phases (T2), to assess the reproducibility of the technique and method error using angular measurements, based on the soft tissue Glabella and soft tissue Pogonion landmarks. The Shapiro-Wilk normality test and intraclass correlation coefficient (ICC) tests, using a two-way mixed model, were applied. To assess the agreement between the NHP and OP methods, Bland-Altman analysis was conducted, followed by regression analysis. The significance level for all statistical analyses was set at 5%.

The ICC analysis for the angular measurement in the NHP position demonstrated good inter-examiner reliability at T1 (ICC=0.706; p<0.001) and T2 (ICC=0.739; p<0.001). In the intra-examiner analysis, only examiner 1 (orthodontist) showed moderate reliability (ICC=0.504; p<0.001). For the OP position, the analysis revealed good inter-examiner reliability at T1 (ICC=0.708; p<0.001) and T2 (ICC=0.704; p<0.001). Again, only examiner 1 (orthodontist) exhibited moderate intra-examiner reliability (ICC=0.530; p=0.033). The Bland-Altman plots demonstrated agreement between NHP and OP for each examiner at T1 and T2.

The NHP and OP techniques were reliable when performed by technically proficient and calibrated professionals.