RADA16 on Mastoid Cavity Epithelialization

The goal of this clinical trial is to see if the application of RADA16 gel can expedite and improve the healing process in participants after canal wall down mastoidectomy. The main questions are: * Does application of RADA16 in the mastoid cavity after canal wall down mastoidectomy lead to faster healing (i.e. epithelialization)? * Is application of RADA16 in the mastoid cavity after canal wall down mastoidectomy associated with a decreased need for medications after surgery (i.e. antibiotics, steroids), less frequent in-office debridements, and less postoperative appointments? Researchers will compare the healing outcomes in participants treated with RADA16 gel to those in a control group who do not receive the treatment. Participants will: * Undergo canal wall down mastoidectomy as recommended regardless of participation in the clinical trial * Follow-up postoperatively for clinical assessment at 1 month, 2 months, 3 months, 6 months, 1 year, 18 months, and 2 years. Participants may follow-up more frequently as needed.