Introduction:
Oral lichen planus (OLP) is a chronic inflammatory disease of the oral mucosa. The purpose to control the disease is to eliminate pain, ulcer, erythema and to reduce the risk of malignancy.
Aim:
The aim of this study is to compare the effects of cryotherapy and local corticosteroids in the treatment of oral lichen planus lesions in patients referred to the oral medicine department of Shiraz dental school. Comparing the difference in severity, size and pain reduction of the two treatments are the objectives of this study.
Methods:
From the patients referred to oral medicine department of Shiraz dental school, 30 patients will be chosen. At the start of treatment each patient will be evaluated by an oral medicine specialist.
Inclusion criteria:
• Clinical diagnosis of oral lichen planus
• Existence of two lesions with similar clinical appearance (with the size difference of less than 1 cm) on the right and left buccal mucosa or right and left side of tongue
• Not received any treatment for the lesions for at least 2 weeks ago
• Signing the consent form.
Exclusion criteria:
• Using drugs that are proved to develop lichenoid lesions.
• Lesions seen in contact with dental amalgam
• Coexisting dermal and genital lesions
• Hypersensitivity to drugs being used
• Pregnant women
• Systemic disease such as systemic lupus erythematosus, erythema multiform, secondary syphilis, graft versus host disease or others systemic disease.
From the existing lesions on the right and left side of the buccal mucosa or tongue, one lesion will be chosen randomly for cryotherapy. The chosen lesion will receive one session of 30 seconds cryotherapy with N2O gas. The temperature will be -72 ̊c. For the treatment of the lesion on the other side (control lesion), patients will be instructed to use a triamcinolone acetonide ointment in orabase 3 times daily for 2 weeks. From the third week the use of the ointment will be tapered (2 times daily on week 3, once a day on week 4, alternate day on week 5 and discontinuation on week 6). The patients will be evaluated in a 3 months follow up program (every 2 weeks) from the beginning of the treatment.
The lesions will be evaluated in the follow up session by a clinician that is unaware of the type of treatment used for each lesion. (Single blind)
Evaluation:
In each session the 2 lesions chosen from each patient will be measured by a digital culis.
The severity of lesions in each site is based on the form reticular (R), plaque type (P), atrophic (A) and erosive/ulcerative (U) and reported as a sum:
Severity of lesion = (R×1) + (P×1.5) + (A×2) + (U×2.5)
The efficacy indices (EI) for the evaluation of treatment outcome are recorded in each session:
EI = (Severity of lesion before treatment – Severity of lesion in the follow up session) × 100 / Severity of lesion before treatment
Pain reduction is measured by the visual analogue scale (VAS).