The possible causes of pain in the right side of the face at the occlusal area are oral ulcers, mumps, and infection of the occlusal space, as follows. 1. Oral ulcers: the buccal mucosa in the right occlusal space may develop oral ulcers due to bite trauma or other irritants, causing pain. 2. Parotitis: including acute suppurative parotitis, chronic obstructive parotitis, etc., which may lead to painful enlargement of the parotid area at the occlusion. 3. Bite gap infection: The bite area on the right side of the face may become swollen and hardened due to infection, often accompanied by pressure pain and limited mouth opening. There may be other reasons for the pain in the right side of the face, it is recommended to go to the hospital in time, with the help of the doctor to clarify the cause of the disease and then give targeted treatment.