Its a disease as reaction to chronic irritation of mucosa by tobacco, smoking , ill fitting denture , sharp tooth etc. Its Very common in tobacco chewers & people who smoke. It appears as whitish or whitish grey membrane on oral mucosa rarely with reddish dots in between. Its a precancerous sign & to be managed with caution. Don't take any mucosal colour change or patch lightly. Proper management is required. Leave the bad habits like smoking & tobacco chewing . These habits are nothing else then gradual suicide. Seek medical attention earliest if any patch.