Dr. Bob: I have a question for you regarding a statement made by a referring orthodontist regarding a 16 year old female patient whose anterior open bite reopened approximately one year following orthodontic treatment. The patient originally underwent orthodontic treatment (completed at age 14) which included palatal expansion, corrected posterior cross bite/crowding and extraction of four 1st bicuspid teeth to level and align teeth and close her anterior open bite. Approximately one year following treatment, the patient’s anterior ope bite reopened 1 – 2 mm and has continued to worsen. The patient’s original orthodontist felt that the anterior open bite relapsed largely due to the steep angle of her mandible and strong skeletal open bite tendency in addition to continued jaw growth of the mandible. Both the original and referring (current) orthodontists do recognize the presence of an abnormal tongue habit/lip incompetence. Airway issues were suspected and have recently been evaluated and are currently being managed. Better late than never to evaluate for airway interferences.
I’m interested in your thoughts on this statement made by the referring (current) orthodontist: “There was some talk of her anterior open bite being associated with jaw overgrowth. But that makes no sense to me. If that were true, it would have caused a posterior open bite, not an anterior open bite. But the reality is that it would not have caused any open bite, because if the teeth were to separate, natural supra-eruption would have brought them back together. The real issue here is tongue habits.”
Is this statement accurate? No, it is not.
I thought that if there was supra-eruption of the posterior teeth (because of potential jaw growth in this case or as a consequence of an increase in normal freeway space due to an interdental tongue posture) then differential eruption would contribute to an anterior open bite. What am I missing here? Nothing. I am impressed that you understand the concepts of the freeway space and differential dental eruption. Well said and well thought out!