The patient in this example is a 42 year-old female who clenched her jaw and presented with bilateral TM ligament pain, left temporal headaches, left neck and shoulder pain, and stuffed-up ears.
The patient stated that her bite changed over time after another dentist inserted four lower crowns in the following order over two years: #18 (e.max), #20 and #21 (e.max, out of contact), and #31 (zirconia) six months prior to her initial occlusal force scan. Zirconia crowns, especially when located on second molars, are extra hard and often create bite issues if they are not in harmony with the joints, ligaments, muscles, and the envelope of occlusion. The deprogramming splint fabricated during her appointment relieved 80% of her acute symptoms in ten days which indicates that muscle triggers and joint positions were responsible for some of her dysfunction.
The difference between the three force distribution cycles above may seem insignificant, but, to this patient, the force distribution cycle on the left, before deprogramming, meant pain and the force distribution cycles in the middle, after deprogramming, and on the right, after adjustment, mean absence of pain and hope! The “after adjustment” pattern profoundly improved the patient’s daily life. Her nagging neck pain disappeared and she is relieved to know that the pain was real and not just “all in her head.”
A force distribution cycle is the baseline measurement of an event that takes place as a mandible engages, stops, and disengages from an upper occlusal plane. The intensity, direction, sequence, and pattern of the force distribution cycle changed, as illustrated by the arrows. Repeating force distribution cycles record a pattern of contact distribution that measures the envelope of occlusion/disclusion.