Very often patients find that they are unable to close their teeth completely in the morning immediately after removing the appliance. This is normal and is due to a temporary jaw joint change. This will generally resolve within 10 or 20 minutes on its own as the joint drifts back into its normal position.
After 20 minutes, jaw exercises are helpful to re-establish joint position and good tooth contact. This can be accomplished by clenching the teeth together and holding for several seconds and then releasing and then repeating the clench/release for a minute or so. Or, you may clench/release on the soft plastic exercise tabs that were provided to you.
Another method is to chew gum while taking a hot shower. Chew and shower for about 10 minutes or until teeth close properly and comfortably.