| This page is for persons who suspect that they may have a
physiological problem that prevents them from getting numb at the
dentist's office. To my knowledge, Joint hypermobility
syndrome, and its variants, especially the severe form known as
Ehlers-Danlos syndrome are the only physiological disorders
that have been associated with causing dental patients to become
refractory to local anesthesia (in other words, it is very difficult
to get the patient numb). This page may help you to decide
whether you fit into this category. My (limited) experience
with Marfan's syndrome, which is a related disorder, has lead me to
believe that patients suffering from Marfan's do NOT suffer
difficulties with anesthetics related to their condition.
Joint Hypermobility Syndrome (JHS) also called HyperMobility
Syndrome (HMS), is one of a group of
inherited conditions which affect the connective tissues of the body.
It is estimated that 10%-15% of normal children have hypermobile joints,
or joints that can move beyond the normal range of motion. Patients
with these conditions are more prone to joint injuries than patients
without. The problems associated with JHS seem to diminish with age,
and persons born with less severe forms of HMS may be unaware of their
condition.
The most severe variant of HMS is called Ehlers-Danlos syndrome.
Persons with this rare variant generally are well aware that they
have a connective tissue problem.
Studies have suggested that as many as half of JHS
patients have enhanced pain perception as well as noticeable pain in
multiple sites in the body. Many seem to respond poorly to local anesthetics
(i.e., at the dentist or during surgery) and require larger dosages for
effective pain control. Most of the evidence for the lack of efficacy
of local anesthetics in patients suffering from less severe form of HMS is
anecdotal, so it is difficult to say with certainty that a patient who seems
refractory to local anesthetics is in fact suffering from a side effect of
an undiagnosed case of JHS. If a refractory patient has a history of a
lot of accidental joint injuries, spontaneous joint pain or knows he or she
is "double jointed", this would be a reasonable avenue to explore.
In patients suffering from the various forms of HMS, the local anesthetic will produce numbness, but it
may be of insufficient intensity or duration to complete the dental
procedure without repeated injections. The reason probably involves the rapid absorption of
the anesthetic solution into the bloodstream due to the defective nature
of the connective tissues in the surrounding blood vessels. If the
anesthetic solution cannot remain in place long enough to take effect,
then the patient will not get numb. The only known way to overcome
this problem is to give repeated, frequent injections during the
procedure.
The following list will help the patient to decide if he or she
may suffer from JHS.
Click here for the reference:
-
Can you now (or could you ever) place your hands
flat on the floor without bending your knees?
-
Can you now (or could you ever) bend your thumb
to touch your forearm?
-
As a child did you amuse your friends by
contorting your body into strange shapes OR could you do the
splits?
-
As a child or teenager did your shoulder or
kneecap dislocate on more than one occasion?
- Do you consider yourself double-jointed?
Physicians may want to assess the nine-point Beighton
hypermobility score (Add one point on each side if the patient can
perform the task for the first four exercises. The hypermobility
score will have a maximum of nine points if all are positive. A
score ≥4/9 indicates widespread
hypermobility.
| Ability to: |
|
Passively dorsiflex the fifth
metacarpophalangeal joint to
≥90° |
1 |
1 |
|
Oppose the thumb to the volar aspect of
the ipsilateral forearm |
1 |
1 |
| Hyperextend the elbow to
≥10° |
1 |
1 |
| Hyperextend the knee to
≥10° |
1 |
1 |
|
Place hands flat on the floor without
bending the knees |
1 |
| Total |
9 |
The Brighton criteria for joint hypermobility
syndrome (JHS). JHS is diagnosed in the presence of
two of the following major criteria, or one major and two minor
criteria, or four minor criteria. Two minor criteria will
suffice where there is an unequivocally affected first-degree
relative
-
Major
-
Beighton score of 4 out of 9, or
more (either currently or historically)
-
Arthralgia for longer than 3
months in four or more joints (Arthralgia means "joint
pain")
-
Minor
-
A Beighton score of 1, 2 or 3 out of 9
(0, 1, 2 or 3 if aged 50+)
-
Arthralgia in 1–3 joints, or back pain
or spondylosis , spondylolysis/ spondylolisthesis
-
Spondylosis is spinal
degeneration and deformity of the joint(s) of two or
more vertebrae
-
Spondylolysis is a defect in a
specific part of a vertebra
-
spondylolisthesis is a forward
dislocation of one vertebra over the one beneath it
producing pressure on spinal nerves
-
Dislocation in more than one joint, or
in one joint on more than one occasion
-
Three or more soft tissue lesions (e.g.
epicondylitis, tenosynovitis or bursitis)
-
epicondylitis is a painful
inflammation of the muscles and soft tissues around an
epicondyle, one of the components in a ball and socket
joint
-
tenosynovitis is an inflammation
of a tendon and its enveloping sheath
-
Bursitis is an inflammation of a
bursa; frequently in the shoulder. A bursa is A
closed fluid-filled sac that functions to provide a
gliding surface to reduce friction between tissues of
the body
-
Marfanoid habitus (tall, slim, arm span
>height, arachnodactyly (long thin fingers)
-
Skin striae (stretch marks), hyperextensibility
(the skin doughy, and velvety to the touch, thin skin
and may have abnormal scarring
-
Eye signs: drooping eyelids, or myopia
(short sightedness),
or anti-mongoloid slant (downward slant to the eyes)
-
Varicose veins, or hernia, or
uterine/rectal prolapse
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