Sometimes all trays are given to the patient at the same time, but usually the patient should expect to get several trays at one time, and return to the doctor for more when those run out.
What you describe is insuuficient posterior support or overly retracted anterior. This can lead to serious problems with the Temporomandibular joints (TMJ, TMD) , headaches, migraines, jaw pain, sinus pain, earaches and/or excessive wear of the antwrior teeth.
Make sure your bite is...
In your particular case, your papillas have become blunted. This can occur following orthodontic treatment in adults if the teeth were significantly overlapped and where then straightened out. In adults, the gum tissue does not usually fill in the embrasure (triangular area between...
