Simulation of Reflectance in Oral Tissue Using MCMatlab

Background

Optical Tissue Properties in the Literature

Tissue Layer	μa [cm⁻¹] 420 nm	μs [cm⁻¹] 420 nm	μa [cm⁻¹] 450 nm	μs [cm⁻¹] 450 nm
Superficial epithelium	3.0	170 (keratinized) / 55 (non keratinized)	2.1	140 (keratinized) / 40 (non keratinized)
Intermediate epithelium	3.0	55	2.1	40
Basal epithelium	3.0	55	2.1	40
Superficial stroma	6.22	267	3.11	248.5
Deep stroma	6.22	267	3.11	248.5
Blood	262	37.8	30	31.1

Methods

Monte Carlo Simulation Principle

(a) Definition of the geometric domain	(b) Random point generation, classification, and counting
Figure 1: Basic Monte Carlo simulation to compute π

Monte Carlo Simulation for Light Propagation

(a) Launching a photon packet	(b) Straight-line propagation over a free path	(c) Interaction event	(d) Updating the Photon Weight
Figure 2: Monte Carlo simulation for light

Results

Fluence Results

Fluence Distribution

Figure 3: Fluence comparison between keratinized and non-keratinized tissue

Absorbance Results

Absorbance Distribution

Figure 4: Absorbance comparison between keratinized and non-keratinized tissue

Reflectance Results

Reflectance Distribution

Figure 5: Reflectance comparison between keratinized and non-keratinized tissue

Influence of Blood Depth on the Optical Response

Fluence Results

(a) Fluence at 415 nm Non-keratinized tissue	(b) Fluence at 415 nm Keratinized tissue	(c) Fluence at 450 nm Non-keratinized tissue	(d) Fluence at 450 nm Keratinized tissue
Figure 6: Fluence distribution as a function of depth for different wavelengths and tissue types

Absorbance Results

Figure 8: Absorbance as a function of blood depth for different wavelengths and tissue types

Reflectance vs Depth

Figure 7: Reflectance as a function of blood depth for different wavelengths and tissue types

Absorbance vs Depth

Figure 8: Absorbance as a function of blood depth for different wavelengths and tissue types

Appendix

Our code can be found at (Github link).