Why do we ask patients to "move their jaw forward and to the left"?
What is the reasoning for the jaw moving forward and to the left in the ‘Supine Active Sacro-Sphenoid Flexion’ technique and forward and to the right in the ‘Active Left Lateral Pterygoid in Protrusion’ technique?
Many of our patients have cranial base function oriented to the right secondary to the human spinal pattern often seen in the human right upper brachium and cranium (Right BC and Right TMCC patterns). These patterns demand on the right lateral pterygoid (mandible often seen oriented to the left) and overdeveloped right sternocleidomastoid (head and neck often seen slightly side-bent to the left and turned to the left) can be reduced by activating the left lateral pterygoid. The left lateral pterygoid assists in rotating the sphenoid or cranium to the left through its attachment on the lateral pterygoid plate of the sphenoid, and the base of the skull and upper cervical spine to the left, through lateral movement of the mandible to the right.
Movement of the mandible to the right promotes good left lateral pterygoid function for meaningful chewing on the right with a balanced forward condyle to fossa relationship on the left during the actual downward power stroke. Movement of the jaw to the right is, therefore, promoted which is so often lost on patients who are very active on their right side when they chew. Right sided chewers over-activate their right lateral pterygoids immediately preceding opening and at the end of the downward power stroke on the right, by moving their mandible to the left after each power stroke. Alternative chewing on both the left and right, is advisable as is keeping lateral pterygoid function balanced, by reducing right neck activity through left lateral pterygoid non-chewing function during the day. The ‘Active Left Lateral Pterygoid in Protrusion’ is one way to keep balanced horizontal movement during mastication and the right cervical muscles relaxed because of the left lateral pterygoid indirect action on moving the cranium (sphenoid) and occipital base (OA/AA) to the left.
Because of the direct attachment of the stylohyoid, styloglossus and stylopharyngeus on the styloid process, moving the mandible to the left “pulls” the right temporal bone into external rotation and flexion, thus reducing intercranial torsion, and intraoral cants associated with the Right Temporal Mandibular Cervical Cranial (TMCC) pattern. This technique reduces hemi-extension of the cranium, restores symmetrical cranial respiratory function and provides a complete base for the tongue to function without compensatory glossus activity. By moving the mandible to the left, the hyoid, dorsal lateral tongue and pharyngeal thyroid cartilage move also to the left, promoting alignment of the airway and pharynx of the Right TMCC patient.