In recent years a portion of the scientific literature and clinical trials have shown an anatomical-functional and pathophysiological connection between craniomandibular and craniocervical dysfunction, connecting various zones of the organism in a single tonic-postural system.
Thus, such literature claims that problems with the back are caused by craniomandibular and craniocervical disorders. In fact, these problems are the object of special studies on the part of gnathologists, who study the role of the jaw in relationship to posture.
To get an idea of what has been established you can look at the following article, which states that there is a possible relationship between malocclusion and scoliosis:
http://www.ncbi.nim.nih.gov/pmc/articles/PMC3162939/
Similarly, in the following article the relationship between malocclusion and postural problems is tacitly assumed:
http://www.ncbi.nim.nih.gov/pmc/articles/PMC3254369/
Gnathology has succeeded in perceiving a relationship between malocclusion and postural problems. It has even succeeded in intervening by means of the bite to alleviate problems of posture.
The following article shows exactly how a bite apparatus fitted for sports can improve performance, by intervening in the case of malocclusion:
http://www.ncbi.nil.nih.gov/pmc/articles/PMC3476490/
Nevertheless, to this day, according to gnathology, it remains impossible to straighten a back, although there continue to be many treatments used: sports (swimming, basketball), gymnastic training, physiotherapy, and even psychotherapy.
In my opinion these treatments don’t solve a single problem and also contribute to making postural problems worse. Besides, as gnathology recognizes, any system in use today won’t resolve such problems completely.
Because gnathology is not capable of demonstrating definitively a positive correlation between malocclusion and problems of posture, part of the scientific literature continues to oppose any theory according to which there is a relationship of cause-and-effect between occlusion and postural problems.
As an example of what has been written, take a look at following article which denies that there is a deeper relationship between malocclusion and posture:
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2910857/
The part of the literature which does not share this view of a relationship between occlusion and posture claims that the skull only rests on the first cervical vertebra. This fact proves, in its opinion, a lack of correlation between occlusion and posture.
All this confirms that there is deep confusion in the scientific world regarding this issue!
However, the issue demands clarification, as patients with important postural problems can be victims of various symptoms: chronic fatigue, diffuse pain, anxiety, panic attacks, gastrointestinal problems, respiratory difficulties, muscle tremors, etc.
There are many health problems that may be caused by malocclusion. Even to this day we do not yet have a complete and definitive map of all the disturbances related to poor posture, but a few studies are exploring this avenue.
These ailments are caused by compressions that have come to be verified within muscles, bones and nerves that are put under strain and torsion arising from the type of malocclusion which creates craniocervical mandibular disorders. For example, a state of anxiety, caused by chronic rigidity of the muscles, could arise from the sinking of the skull where there is a lack of dental height. We will go deeper into this phenomenon later.
As an example, take a look at the following article which deals with the relationship between malocclusion, posture and vision: