The principal research objective is to provide enhanced understanding of the cellular and molecular events important in the pathogenesis of Oral Lichen Planus to enable improved diagnosis and development of novel treatments for patients.

The following questions will also be addressed:

1. Are the histological architectural tissue changes that take place in oral lichen planus quantifiable using computer based imaging, graph theory and fractal geometry principles? Quantification of these changes would allow the development of a tool to facilitate the accurate measurement of response to treatment.
2. What is the nature of such architectural changes and what are the differences with normal, dysplastic and neoplastic epithelia (the investigators have morphometrical data collected from previous research to allow such comparisons).
3. Is it possible to produce evidence-based statistical classification into established diagnostic classes using the proposed methodology? This would contribute towards making histopathological diagnosis more quantitative, reproducible and accurate.
4. Is it possible to automate such morphometrical analysis/classification? This would allow large data sets to be screened automatically in a shorter time frame and at lower cost than human based screening.
5. Is it possible to determine differences in genetics and gene expression of keratinocytes involved in Oral Lichen Planus compared to those of 'normal' tissue by using biopsy material and an in vitro model of oral lichen planus?

Inclusion Criteria:

1. Patient is 16 years old or over
2. Patient is willing and able to provide valid informed consent
3. Patient is attending the Oral Lichen Planus clinic and will be having a routine clinical biopsy taken

Exclusion Criteria:

1. Patient under 16 years old
2. Patient is immunocompromised
3. Patients with comorbid disease state e.g. other inflammatory disease

Patients registered at Birmingham Dental Hospital and attending a clinic for OLP diagnosis.

Patients will be identified by their normal healthcare consultant and invited to participate.

Informed consent will always be obtained prior to any study related procedures being undertaken.