The relationship between the eyes and the mouth is a surprise to patients, some patients find relief from their instability or headaches when the orthodontist restores good occlusal contact or when we relax the chewing musculature or improve the position of the TMJ.
There is evidence of the relationship between occlusion and posture, alterations in the muscular balance of the body can influence the position of the jaw and facial morphology, and in turn we know that changes in jaw position can influence the cervical muscles and the posture of the neck, head and the rest of the body. The mouth is essential for the mechanical and neurological balance of the cervical spine, the skull and especially the eyes.
The mouth is an important input of information to the postural system. It provides important information of two types. On the one hand, it provides proprioceptive information from the temporomandibular muscles and joints, and on the other hand, it provides exteroceptive information from the occlusal contact. In both cases the information coming from the mouth is at the same time information from the skull. The jaw articulates with the skull and any masticatory muscle or any occlusal contact is manifesting how and in what way the skull is positioned in space. Every structure that informs the position of the head is fundamental to the postural system. The nervous system uses this information coming from the mouth together with that coming from the vestibular system, vision and cervical and ocular proprioception for the control of posture and balance.
The oculomotor system and the stomatognathic system are connected, not only by mechanical structures, but also because both systems are innervated by the trigeminal nerve.
Neurologicallyboth the eyes and the mouth are innervated by the V cranial nerve or Trigeminal Nerve. It is a so-called mixed nerve as it has motor fibres, which are linked to mastication, and also sensory fibres, which innervate part of the face. At the trigeminal ganglion it divides into three branches:
- Ophthalmic branch (V1): fully sensitive. It innervates the eyeball, the lacrimal gland, the skin of the nose, forehead, eyelids, nasal mucosa and part of the scalp.
- Maxillary superior branch (V2): is also purely sensory. It innervates the lower eyelids, the wings of the nose, the lacrimal gland, the palate and the upper teeth. This is a branch that relates directly part of the eye with the jaw area.
- Mandibular branch (V3): It is a mixed or sensory-motor nerve. It innervates the meninges, temples, jaw, lower teeth and tongue.
Studies have shown a strong correlation between occlusal, muscular or articular alterations in the mouth and the decompensation of an oculomotor pathology.
In pathologies such as malocclusions (crossbites, open bites, etc.), missing teeth, or temporomandibular dysfunctions, what is presented is a permanent situation of imbalance. This will require a joint approach between specialists in order to guarantee success.
In a nutshell
The mouth is part of a craniocervical mandibular system and has a great influence on the cervical spine and the position of the head.
The mouth is also an important postural sensor. Information from the TMJ, masticatory muscles or periodontal ligaments, i.e. all trigeminal information, reaches nerve centres in the brainstem linked to postural control. Through the medial longitudinal fasciculus, trigeminal information has connections with the oculomotor nuclei, so that an evidence in the information coming from the mouth can destabilise an oculomotor problem.
Bibliography: Manual therapy of the oculomotor system
