Facial biometrics of peri-oral changes in Crohn's disease.

Crohn's disease is a chronic relapsing and remitting inflammatory condition which affects any part of the gastrointestinal tract. In the oro-facial region, patients can present peri-oral swellings which results in severe facial disfigurement. To date, assessing the degree of facial changes and evaluation of treatment outcomes relies on clinical observation and semi-quantitative methods. In this paper, we describe the development of a robust and reproducible measurement strategy using 3-D facial biometrics to objectively quantify the extent and progression of oro-facial Crohn's disease. Using facial laser scanning, 32 serial images from 13 Crohn's patients attending the Oral Medicine clinic were acquired during relapse, remission, and post-treatment phases. Utilising theories of coordinate metrology, the facial images were subjected to registration, regions of interest identification, and reproducible repositioning prior to obtaining volume measurements. To quantify the changes in tissue volume, scan images from consecutive appointments were compared to the baseline (first scan image). Reproducibility test was performed to ascertain the degree of uncertainty in volume measurements. 3-D facial biometric imaging is a reliable method to identify and quantify peri-oral swelling in Crohn's patients. Comparison of facial scan images at different phases of the disease revealed precisely profile and volume changes. The volume measurements were highly reproducible as adjudged from the 1% standard deviation. 3-D facial biometrics measurements in Crohn's patients with oro-facial involvement offers a quick, robust, economical and objective approach for guided therapeutic intervention and routine assessment of treatment efficacy on the clinic.

Quantitative optical coherence tomography of fluid-filled oral mucosal lesions.

The decision of selecting the most representative site for the biopsy of fluid-filled lesions can be difficult. This may be attributed to the poor delineation of the correct lesional site by clinical observation alone. In this study, optical coherence tomography is used to quantify the contrast between solid- and fluid-filled lesions by measuring the light intensity change at the tissue-fluid interface (intensity drop). This parameter was measured from sequential axial scans (n ≈ 10(6) per sample) of 3D optical coherence tomography (OCT) datasets from control tissues (n = 14) and fluid-filled lesions (n = 7) and displayed as a 2D-scaled intensity drop (SID) image. The results of the SID image allowed for discrimination, characterisation and extent of a fluid filled region. The differentiation of normal and fluid-filled areas using individual SID values yielded both a sensitivity and specificity of approximately 80 %. OCT complemented by SID analysis provides a potential in vivo clinical tool that would enable non-invasive objective visualisation of the oral mucosa.