Gnathology

Gnathology
Gnathology and posturology is a branch of dentistry that deals with cranio-mandibular disorders, that is, the dysfunctions and pathologies of the chewing system from a non-strictly dental point of view.
Thus, gnathology deals with joints and muscles and in particular with the joint between the mandible and the skull (Temporo Mandibular Joint or TMJ) and the system of elevating and lowering muscles of the mandible. Dysfunctions of these anatomical structures are extremely common, although they generally go unnoticed because the disorders are not always symptomatic.
Posturology studies the relationships between body posture and certain algic disorders.
The Problems and Diagnoses of Gnathology and Posturology.

Teeth can be primary or secondary causes of gnathology and posturology problems. Symptoms such as tinnitus, muffled hearing, dizziness, headaches, neck and scapular pain, visual impairment (strabismus) or visual fatigue, and back pain can sometimes be related to a gnathological problem.
The main approach consists of a series of tests and observations that first help distinguish whether the problem is articular or muscular. The most important instrumental examination in the field of gnathology is Magnetic Resonance Imaging (MRI), which allows visualization of a very important element of the TMJ, namely the articular disc. By combining the clinical examination with MRI, the gnathologist will be able to make a correct diagnosis and suggest an appropriate treatment plan.

The anatomy of mastication
The anatomical structures involved in gnathology are the jaw, joint disc, skull base, muscles and ligaments. Clicks, rubbing noises, blockages when opening or closing the mouth, deviation of the jaw when opening, are all expressions of a suffering of the joint system.The position in which we close the mouth is determined by the position of our teeth. It happens that the position that the jaw (the lower part) takes in relation to the jaw (the upper part) is not always the most comfortable for the muscles of the face and neck and the temporomandibular joints. Sometimes the correct position is different from the position in which the teeth "fit," in which cases the jaw may be too far forward, too far back, or shifted laterally.Some people have a more "closed" bite than it should be, either because the teeth are shorter (due to wear or reduced eruption), or because they are very tilted, or because they are missing. This has a huge effect on the position of the neck and head, which, under normal conditions, is balanced on the shoulders and the neck muscles do not struggle at all to support it.When due to improper occlusion the head moves forward, it forces the neck muscles to overwork to support it; at the same time, the efficiency of these muscles is also greatly reduced, increasing fatigue. Dental occlusion also affects the function of the temporomandibular joints, determining the position of the condyles, which are the portions of the jaw that articulate with the skull. Between the two parts, the first convex and the second concave, is interposed the articular disc, which serves to make movements more fluid, and which, under normal conditions, follows the condyle in its movements.

The disorders of the temporomandibular joint
Imbalances and gnathological disorders can generate the onset of orthopedic pathologies (scoliosis, lumbago, cervicalgia, etc.) that we could define as secondary to a primary pathological involvement of the mouth apparatus.These mechanisms can also act in reverse, that is, there could be the case in which a muscular imbalance coming from other body districts determines for the mechanisms of muscular interconnection problems atm.In all cases we will witness over time a postural type of problem. That temporo mandibular is one of the joints most involved in postural imbalances, so collaboration between dentist-posturologist and physiotherapist-posturologist is necessary both in performing differential diagnostic tests and subsequently in setting the most appropriate therapeutic course.TMJ disorders can be classified into a few broad categories.

Disk dislocation with reduction (dislocation or click)
This disorder occurs when the disc (with the mouth closed) is not in the correct position above the condyle, but shifted forward. When the jaw opens. the condyle jerks forward, repositioning itself under the disc with a characteristic sound called "clicking."

Disk dislocation without reduction (locking or locking)
As in the previous disorder, in this situation, the disc is in front of the condyle when the condyle is in the initial position with the mouth closed. The difference is that as soon as the jaw begins its opening movement, the condyle fails to recapture the disc and therefore "reduction" (= there is no "click") does not occur. The result is a restriction of jaw movement with a lower than normal opening.

Ligament Compression
In all situations where the disc is not in the correct position, the condyle of the jaw rests on a normally uninvolved part: the posterior ligament of the disc. This anatomical structure is rich in blood vessels and nerves, so it can happen that jaw movements are also very painful due to the continuous stress on sensitive parts and the formation of fluid effusions in the joint capsule. Sometimes there is a joint noise similar to a rubbing of sand, or crumpled paper, due to the rubbing of bony parts against each other.

Disorders of the musculature
Gnathological disorders of muscular origin are often very painful. The muscles that are found to act to move the jaw in all directions are many, and they hurt when they work too hard or badly, going into contracture, fatigue, and spasm. The causes are many, complex and sometimes difficult to recognize, but can be summarily distinguished as follows:
* Clenching - This is the patient's habit of holding the teeth in very close contact and pulsating the clenching muscles.
* Bruxism - This is the habit of rubbing the teeth tightly together causing them to slide in all directions (grinding) sometimes even producing noise. Both of these phenomena are in most cases due to non-dental causes: the patient vents the stresses of daily life in this way, for example. The result is a variety of consequences, including abrasion or fracture of teeth and muscle issues.
* Spoiled habits - A classic example is the constant use of chewing gum: it forces the muscles to work unnecessarily for hours, with the already described consequences.
* Occlusal problems - In a small number of cases, actually the closing position of the two dental arches (occlusion or "chewing") can cause a jaw posture problem that is compensated for by asymmetrical muscle tension: in order to maintain the position of the teeth, the muscles are forced to work poorly.

Bruxism and tooth clenching
These are the main sleep-related movement disorders of the stomatognathic system. Bruxism literally means teeth grinding and is an involuntary contraction of the masticatory muscles, lasting about 5-10 seconds and repeated during sleeping hours. The causes of these movements are not entirely clear, but malformations, familial factors and psychological factors (stress, aggression) contribute.It is a difficult condition to diagnose in the field of gnathology and posturologists, because spent does not impair sleep itself. Beyond the help of partners, family members, and roommates, who may notice this unconscious habit, pain in the mouth, jaw, neck, and headache upon waking are useful alarm bells for seeking dental advice. If neglected, bruxism can lead to serious damage to teeth and gums due to protracted erosion of enamel, wear of teeth and their supporting elements, deepening of microfractures, and joint wear.For clenching, the side effects are the same, although generally of lesser intensity. Damage may be greater if fillings, capsules or implants are present. There is no definitive treatment for bruxism, but there is a device, called a bite, to prevent damage caused by tooth rubbing.

The Bite
It is a transparent mobile appliance that is made from impressions of the patient's teeth. It is made to individual parameters and is prescribed by the dentist. It can help maintain correct posture, also prevents teeth grinding or clenching during the night and can help resolve any headache issues.In cases of nocturnal bruxism, it has a threefold effect: it protects tooth enamel from rubbing, restores the correct alignment of the dental arches, and reduces muscle tension in the jaw and neck.A soft bite helps achieve relaxation of the masticatory muscles and is indicated in cases of muscle-tensive symptoms. A rigid splint, on the other hand, is indicated in the correction of vicious habits and parafunctions, such as bruxism and clenching.


Therapy of craniofacial disorders
Cranio mandibular disorders have different treatment approaches depending on the diagnosis. These are mainly movements to recondition the joints, muscle relaxation therapies, and devices with orthopedic function (splints).
* Jaw exercises - These are a set of exercises and movements that are performed both to try to recover classic joint disorders (clicks) and to achieve lengthening (stretching) and muscle relaxation.
* Neuromuscular Bite - This is a clear resin plate that is applied over one arch (usually the upper arch) and brings the teeth to close on a different, specially created surface. The goal is to achieve a position of comfort for the patient, in which there is good relaxation of the muscles. It can also be used as a protective function for teeth in cases of parafunction (bruxism and clenching).
* * Repositioning Bite - This is a special splint that is used exclusively for dislocation therapy with reduction. It is mounted on the upper arch and has a slide inside the mouth that forces the mandible to close in the forward position, and particularly in the position where, having moved the condyles forward and recaptured the disc, the click disappears in the movement. Subsequent adjustments will serve to bring the patient into the most therapeutically advantageous position.
* * Distraction Bite - This splint is built on the lower arch and is basically a neuromuscular splint to which a precontact (point that touches first) has been created on one side only, so that the patient, closing the teeth, will not be able to close them all, but will have a single contact on that side only. It is used in cases of posterior ligament compression and is then adjusted until symptom improvement is achieved, after which it is changed back to neuromuscular