I grinned too. At that time, I planned to go to the dentist for orthodontics and let my teeth go up. Then Dr. Lu showed me that I smiled because my crown was short, and the improvement would not be particularly obvious if I did orthodontics. Then I listened to the doctor's advice and had a crown lengthening operation, and then I made a porcelain veneer. Now it's just like a normal smile ~ ~ similar to this feeling.
If it is because the muscles of the upper lip are too developed and the whole upper lip is covered with laughing muscles, botulinum toxin can be used to weaken muscle tension.
However, some serious bone giggling may require orthodontic treatment, and it is best to see a doctor.