Is it true biting your cheeks cause mouth cancer? I do it on accident couple times when chewing gums because of my. Back molars

No. Mouth cancer is caused most by alcohol and tobacco use, including smoking and chewing/smokeless tobacco. This usually presents by 50 years of age, and in the form of non-healing ulcers that can be painful. Teenagers might get it if they are particularly susceptable and do a lot of smoking, drinking alcohol, and chewing tobacco. Biting your cheeks should be discouraged, but it does not do this.
In a word, no. Although there is some theoretical support for the belief that chronic inflammation can lead to malignancy, local acute physical trauma in the mouth has never been shown to promote oral cancer. The chief risk factors for oral cancer are currently believed to include tobacco, alcohol, ionizing radiation, and certain strains of human papilloma virus (hpv).
NO. Oral cancers are associated with smoking, heavy alcohol use and human papilloma virus infection (especially base of tongue and tonsils). Minor trauma such as bites are not associated with cancer. Poor fitting dentures may increase risk but more likely due to trapping substances like tobacco residue.
Mild possibility. Any oral lesion that persists for a long period of time adding a carcinogenic substances such as tobacco smoking or chewing, alcohol or drug abuse is a potential risk to cancer or severe complication of the lesion. Adjusting the bitting surface or position of these teeth or in some cases extracting is the best approach.