As the
name suggests, the mobility of the jaw is limited with a jaw clamp. The
technical term for this is called ankylostoma and describes a condition in
which the mouth can only be opened with pain or not at all. This is where
a jaw clamp differs from a jaw lock , in which
the mouth can no longer be closed.
A jaw
clamp is not a disease in its own right , it is just a symptom . There can be numerous causes behind
this, from muscle cramps to inflammation to a slipped cartilage disc. In
order to get rid of a clamp, the first thing to do is to find the
cause. The good news: Jaw clamps are rare. Although they are very
uncomfortable, they are usually harmless. If they don't go aways on their
own, removing their trigger will usually bring the desired result.
Form and duration of a clamp
Doctors
differentiate between different degrees of severity of a clamp. This helps
doctors classify the findings and better assess the course of therapy. To
do this, they measure the incisal edge distance, i.e. the distance between the
edges of the incisors of the upper and lower jaw at the maximum possible mouth
opening. They divide the result into one of three degrees of severity:
- Grade 1: Slight and
subjectively restricted mouth opening
- Grade 2: Maximum mouth
opening 10 millimeters
- Grade 3: Maximum mouth
opening 1 millimeter
Depending
on whether the clamp occurs on one or both sides, experts speak of a unilateral
or bilateral clamp. How long such a jam lasts cannot be answered across
the board. That depends on factors such as the cause, the severity and
concomitant diseases. In any case, a little patience does not hurt: In
contrast to a lock, which can often literally be adjusted again within seconds,
a clamp can drag on for weeks and months and only loosen in small
steps. Nevertheless, in most cases it disappears completely.
Causes of a jaw clamp
Since a
jaw clamp is a symptom of another condition, it can have many
causes. Therefore, the diagnosis can sometimes require a little
tinkering. We have listed the most common triggers here.
Muscular causes
Sometimes
the interplay between the temporomandibular joint and the masticatory muscles
is unbalanced. In many cases, the muscles are responsible for
this. If they cramp, the mouth opening closes - because the mouth closers
are naturally stronger than the mouth openers. Because jaw clamps occur
relatively often as a result of muscle spasms, there is a separate term for it:
trismus.
Such
cramps can have various causes. They are, for example, a typical symptom
of diseases such as tetanus (tetanus), meningitis ( meningitis ) or the Hecht syndrome, a genetic disease
in which the mouth is restricted from birth. In the case of an epileptic
seizure, a seizure caused by a mental disorder or a tetany, i.e. overexcitable
nerves and muscles, jaw clamps are common symptoms.
In
addition, jaw clamps can occur in the case of a skull base fracture or a tumor
on the parotid gland (parotid tumor) - this is a tissue overgrowth near the
parotid gland. Apart from these diseases, amphetamines such as speed or
ecstasy can also trigger muscle spasms, which often affect the chewing
muscles. Drug use is therefore also one of the triggers.
However,
in most cases the causes are far less dramatic: Sometimes the masticatory muscles
tense simply as a result of stress and
psychological stress, postural damage, a bad bite, after long dental treatments
or harmful habits such as jaw clenching or crooked
chewing. Nocturnal teeth grinding (bruxism) or a dysfunction of the
jaw (CMD: craniomandibular dysfunction ) are also possible
triggers because they put a lot of strain on the masticatory muscles in the
long term. And last but not leasts, there are a number of other causes
that have nothing to do with the muscles.
Mechanical causes
Mechanical
causes can also be considered as triggers for a clamp. The
temporomandibular joint itself often causes problems: if the disc is displaced,
for example, the cartilaginous intermediate joint disc (disc) slips. It is
usually located in the joint space of the temporomandibular joint, i.e. between
the joint socket of the upper jaw and the joint head of the lower
jaw. There it ensures that movements run smoothly. However, if it
slips, it blocks precisely this mobility and can cause a jaw clamp.
In some
cases the joint disc even pops out, which is equivalent to a kind
of herniated disc in the temporomandibular joint and is
known as a disc prolapse . Both clinical
pictures are often announced months in advance by cracking and grinding noises
and / or pain in the jaw and can ultimately lead to a clamp. Such
cartilage damage can also occur on one side. In this case, the lower jaw
deviates towards the diseased side when the mouth is opened.
Fractures
can also cause jaw clamps in a mechanical way, for example as a result of falls
or blows. In the case of a lower jaw fracture at the level of the joint
neck or a cheekbone fracture, for example, they often occur because splinters
get into the joint and block its mobility. But bones don't always have to
break: Sometimes a dislocation of the lower jaw (jaw dislocation) is enough to
trigger the symptoms.
Such a
dislocation can occur after an accident or after opening the mouth wide - for
example with a hearty yawn or a bite into a large fruit. Due to the
extreme opening, the heads of the temporomandibular joint slide out of the
joint socket in the upper jaw. In most cases this leads to a lock in the
jaw, but sometimes it also leads to a jaw clamp.
In
addition to fractures and cartilage damage, degenerative diseases such as TMJ
arthritis, extensive hematomas or tumors can also be considered as mechanical
triggers. In the case of cancers in the mouth and throat, tissue
overgrowths can press the jaw so unfavorably or cancer cells penetrate the
masticatory muscles that a jaw clamp occurs. The risk is greatest with
tumors in the upper throat area, the oral cavity, the nasopharynx, the larynx
or the salivary gland on the ear.
In short:
for tumors that are close to the jaw. A restricted mouth opening can also
occur as a side effect of cancer therapy, usually as a result of scarring after
surgery or radiation therapy . The risk of this varies with
the location of the tumor and the radiation dose.
Inflammatory causes
Inflammatory
processes can also be the cause of a clamp. The symptoms occur relatively
often, for example, in connection with the eruption of the wisdom teeth , less often with the eruption of milk
and canine teeth. If everything does not go smoothly, doctors speak of
"difficult tooth eruption" (dentito difficilis), which can lead to
swelling, pain and fever . Often, the limited
space in the jaw is responsible for this.
The
problem: The
teeth that have not fully erupted are covered with loose mucous membrane, which
forms an ideal niche for bacteria. They have an easy job and can quickly
lead to inflammation of the mucous membranes or gums , which can
radiate into the jaw. In severe cases, abscesses can form, which can cause
a very painful jaw clamp. The line between mechanical and inflammatory
causes blurs here, as swelling caused by an infection occurs.
A clamp
can also occur when the temporomandibular joint or its surroundings are
inflamed (e.g. tongue, parotid gland, tonsils, periosteum), but these cases are
extremely rare. The same applies to so-called syringe abscesses, in which
a purulent infection forms at the puncture site. This sometimes happens
after an anesthetic injection at the dentist.
Jaw clamp after dental surgery
Since a
dentist performs many procedures under local anesthesia, what is known as an
injection abscess can occur. The doctor numbs the main nerve that runs
through the entire lower jaw. Although this is a routine prick, there is a
risk of injuring nerves or blood vessels or inadvertently introducing the
anesthetic into the masticatory muscles when the needle is punctured - the
insertion of the cannula is “blind” and requires experience.
In
contrast to taking blood from the crook of the arm, for example, the dentist
cannot see or feel the perfect puncture site. If something goes wrong with
the injection, it can lead to bleeding, intramuscular inflammation, nerve
irritation or hematomas, all of which can result in a jaw clamp. This can
last for a few weeks or months, but usually disappears again and does not cause
any consequential damage.
In
addition to the anesthetic injection, other factors can cause or worsen the
problem: For example, a muscle spasm from keeping the mouth open for a long
time during an operation, swelling and / or bruises on the treated area or
local inflammation. Pine clamps occur particularly often after the removal
of all wisdom teeth in one session, as the doctor has to stretch the jaw to the
maximum in order to reach the teeth and considerable external forces act on the
jaw as a result of the pulling. This can damage the chewing muscles and
temporarily limit their functionality. Patience is required to recover:
Even after a wisdom tooth operation, it can take a few weeks to months for the
clamp to loosen completely.
