Research Paper
Imaging
A study to evaluate the reliability of using two-dimensional photographs, three-dimensional images, and stereoscopic projected three-dimensional images for patient assessment

https://doi.org/10.1016/j.ijom.2016.11.011Get rights and content

Abstract

Clinicians are accustomed to viewing conventional two-dimensional (2D) photographs and assume that viewing three-dimensional (3D) images is similar. Facial images captured in 3D are not viewed in true 3D; this may alter clinical judgement. The aim of this study was to evaluate the reliability of using conventional photographs, 3D images, and stereoscopic projected 3D images to rate the severity of the deformity in pre-surgical class III patients. Forty adult patients were recruited. Eight raters assessed facial height, symmetry, and profile using the three different viewing media and a 100-mm visual analogue scale (VAS), and appraised the most informative viewing medium. Inter-rater consistency was above good for all three media. Intra-rater reliability was not significantly different for rating facial height using 2D (P = 0.704), symmetry using 3D (P = 0.056), and profile using projected 3D (P = 0.749). Using projected 3D for rating profile and symmetry resulted in significantly lower median VAS scores than either 3D or 2D images (all P < 0.05). For 75% of the raters, stereoscopic 3D projection was the preferred method for rating. The reliability of assessing specific characteristics was dependent on the viewing medium. Clinicians should be aware that the visual information provided when viewing 3D images is not the same as when viewing 2D photographs, especially for facial depth, and this may change the clinical impression.

Section snippets

Subjects

Ethical approval for the study was obtained from the Institutional Review Board (IRB) of Hong Kong University and Hospital Authority Hong Kong West Cluster. Forty pre-surgical orthognathic patients attending the Department of Orthodontics or the Department of Oral and Maxillofacial Surgery of Prince Philip Dental Hospital, Hong Kong, were recruited. All patients had previously been diagnosed with a skeletal class III deformity by the orthognathic team and required surgical correction. Patients

Results

The inter-rater reliability was good to excellent (Cronbach's alpha ≥0.8) for the three different viewing media when assessing the three components of the face, i.e. height, symmetry, and profile (Table 1). Cronbach's alpha ranged from 0.82 for assessing facial height using 3D images to 0.97 for assessing symmetry using projected 3D images.

All ICC values for assessing intra-rater reliability were between 0.48 and 0.76, representing moderate to good levels of reliability.11 There was a

Discussion

This study reports on the reliability of using 2D photographs, 3D images, and stereoscopic projected 3D images to assess the severity of the condition in patients with a class III dentofacial deformity. This study is different to previous studies in two main areas. Firstly, rather than assessing the global facial attractiveness or beauty of the individual as an outcome measure, specific facial characteristics were assessed, i.e. height, symmetry, and profile. This provides a more objective

Funding

None.

Competing interests

None.

Ethical approval

Ethical approval was granted by the Institutional Review Board (IRB) of Hong Kong University and Hospital Authority Hong Kong West Cluster (Protocol Reference No. UW 14-355).

Patient consent

Written patient consent was obtained to publish the clinical photographs.

Acknowledgements

The authors would like to thank the eight raters for their time and support in conducting this study and the staff of the Oral and Maxillofacial Discipline for patient recruitment. We would also like to acknowledge Samantha Li for her statistical advice.

References (19)

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