It has been said that there are no easy cases, and I think that I believe it after the run of new patients I've had the past six months. So, once again, I am turning to all of you to get your thoughts on unusual circumstances. This woman was referred for a restorative evaluation by one of the great periodontists with whom I work. She is 55 years old and has a failing bridge that is severely periodontally involved. The bridge is 13 years old. She reports that she grinds her teeth and wakes up with right-sided headaches several times a month. She also reports that the only teeth that touch are on the left side and that has only been that way for the past two years or so. She states she was in an abusive relationship 14 years ago and that she has been struck in the face and remembers being hit on the right side very hard. On exam, there is no muscle tenderness except for a slight tension in the R temporalis. She has a fully normal range of motion, although she struggles to move laterally in either direction. Doppler exam was positive for crepitus bilaterally throughout the range of opening, closing and lateral movements. The CBCT shows beaking of both condyles on the medial poles. The only contact she has is in the left posterior dentition and her midline is off to the right by about 2 mm. OK, so here is the question for this blog. What the heck is going on???? What do you see that are clues and what do you think is causing the unilateral posterior open bite? Has she always been this way or is it really something new?

Front view with lips retracted, maximum intercuspation.
Front view with mouth slightly open.
Side view with lips retracted, Occlusal
Panoramic view of the bottom teeth from the top.
X-ray of the left joint.
X-ray of the cross-sectional.


Commenter's Profile Image Paul Ganucheau
January 3rd, 2012
Does she have degenerative joint condition in the left condyle? If the head of the left condyle is remodeling or deteriorating away, that would explain the unilateral posterior contact. Did she have any history of trauma, joint noises, or crepitus? Paul
Commenter's Profile Image Paul Ganucheau
January 3rd, 2012
Sorry, missed the history of domestic physical abuse. I think the left condyle is degenerating based on the history of abuse and trauma. Paul
Commenter's Profile Image Mike Weisbrod
January 9th, 2012
Is there a significant deviation of the jaw to the right on opening? This might be a sign that a problem exists in the right TMJ. Also the unilateral open bite on the right would mean that anytime she is in MIP, or possibly just chewing more on the left where the teeth touch, she would be loading the right side TMJ. The constant load to the right TMJ would cause some aggravation. What is going on? Well, I am guessing some right side TMJ arthralgia (with degeneration due to previous trauma?) with associated Lateral Pterygoid muscle spasm causing the shift in the bite. The temporalis on the right side is probably tender due to bracing and trying to get the right side to close. Look forward to learning more about the case!