Hello, Your medications most likey have the side effect of a dry mouth. You must keep well hydrated and rinse your mouth often. There are dental products including toothpaste, rinses, sprays ang gum designed for patients with zerostomia. Chewing sugar free gum with xylitol can stimulate saliva flow. Avoid irritants such as smoking and alcohol that will dry out the mouth. Limit high sugar content foods and acidic foods. Your mouth may have a thicker plaque and require greater attention to your daily oral hygiene to avoid an increase in decay at the gum line. Protect your teeth with additional flouride such as a rinse along with flouride in your toothpaste. See if a change in medication or combination of medication can help your saliva flow. Breathing through your mouth will contribute to lip dryness. Rule out any other medical conditions affecting saliva flow. Make sure your dental exam does not indicate any dental conditions that need attention. If you are missing back teeth and your bite has collapsed, you may have salvia leak out at the corners of your mouth and contribute to cracking of th lips. Keep your lips moist by using moisturizing balms. Do not over use the Orabase ointment. Continue with vitamin B-12. Rule out any deficiencies and maintain a proper diet. Thank you for your inquiry. I hope you find my suggestions helpful.