To manage severe bruxism in a post-cranioplasty patient, doctors often prescribe muscle relaxants like baclofen or gabapentin. Botulinum toxin injections directly into the jaw muscles are also highly effective at reducing the grinding force. For the lip ulcer, keeping the tissue protected is crucial. Applying a topical barrier ointment like medical-grade petroleum jelly or a soothing dental paste containing triamcinolone acetonide can promote healing. Additionally, using a soft bite block or mouthguard can physically prevent further lip trauma. Please consult the patient's medical team to safely coordinate these treatments.