A 19-year-old young man complains of constant pain in tooth 22, which intensi?es on biting with this tooth, sensation of "protruding" tooth, and upper lip edema. The patient has history of upper jaw trauma. Objectively tooth 22 is intact. Vertical percussion is acutely painful. The upper lip is swollen, mucogingival fold in the area of tooth 22 is red and painful on palpation. What examination method is necessary for diagnosis making in this case?