Risk of the Contralateral Mucosa in Patients with Oral Potentially Malignant Disorders

Background: It is known that abnormal changes may occur in any part of the oral mucous membraneexposed to a carcinogen. Therefore patients with oral potentially malignant disorders (PMDs) are at risk ofdeveloping similar lesions at multiple sites.
Objectives: To determine the risk of the contralateral mucosa inpatients presenting with oral PMDs. Materials and methods: Sixty individuals with PMDs were selected for thisstudy. These comprised 32 (53.3%) Indians, 23 (38.3%) Chinese, four (6.7%) Malays and one (1.7%) Nepalese.All selected cases had histopathological confirmation of their primary existing lesion as inclusion criteria. Casesthat subsequently presented with a lesion in the corresponding anatomical site also underwent scalpel incisionalbiopsy on this second lesion to verify its diagnosis. The remaining cases that presented with unilateral PMDs atthe time of study were subjected to a cytobrush biopsy on the normal looking contralateral mucosa.
Results: Atotal of 70 primary PMDs were detected in 60 patients. The most common PMD found was oral lichen planus(n=40, 57.1%). Of the 60 patients studied, 28 (46.6%) exhibited bilateral lesions either synchronously (n=21,35.0%) or metachronously (n=7, 11.6%). The remaining cases that had undergone cytobrush biopsy on thecorresponding anatomical site yielded normal cytological results.
Conclusions: Present findings demonstratedthat patients presenting with PMDs in the upper aerodigestive tract are at a greater risk of developing a secondlesion most probably in the contralateral anatomical site.