https://www.tandfonline.com/doi/abs/10.1080/08869634.2018.1498181

I came across this article during one of my “nerd safaris” last month and have been eager to comment on it ever since. It comes from some really great medical doctors in Turkey (the country, not the Thanksgiving meal…) . There were several interesting nuggets in this article:

The gold standard measurements of normal vs abnormal cervical curve measurements come from a contemporary chiropractic researcher that is often overlooked in our own profession (Dr. Harrison).
The research looked at the correlation between neck lateral alignment (referred to as sagittal alignment or lordosis), and TMJ symptoms, rather than jaw pain and neck pain. This is important because mechanical problems of the neck can cause pain and compensatory problems elsewhere in patients who have little to no neck pain. In other words, still important to look at the neck posture even if people think their neck is “fine”.
All of their TMJ symptomatic patients showed abnormal cervical curve.
Patients with the higher abnormal cervical curve measurements and TMJ pain also had higher depression scores. Pain and neurological stress from the upper spine is not good for mood management.

Bottom line- Patients with TMJ issues benefit from having their cervical spine evaluated for abnormal shifting, as it appears to be a contributing factor.