Dislocation of the temporomandibular joint
may occur for various reasons. Although
different invasive methods have been advocated
for its treatment, this study highlights the
value of non-invasive treatment options even in
chronic cases in a resource-poor
environment.
MATERIALS AND METHODS:
A seven-year retrospective analysis of all
patients managed for temporomandibular joint
dislocation in our department was undertaken.
Patient demographics, risk factors associated
with temporomandibular joint dislocation and
treatment modalities were retrieved from patient
records.
RESULTS:
In all, 26 patients were managed over a
seven-year period. Males accounted for 62% of
the patients, and yawning was the most frequent
etiological factor. Conservative treatment
methods were used successfully in 86.4% of the
patients managed. Two (66.7%) of the three
patients who needed surgical treatment developed
complications, while only one (5.3%) patient who
was managed conservatively developed
complications.
CONCLUSION:
Temporomandibular joint dislocation appears
to be associated with male sex, middle age,
yawning, and low socio-economic status,
although these observed relationships were not
statistically significant. Non-invasive methods
remain an effective treatment option in this
environment in view of the low socio-economic
status of the patients affected.
I. Introduction
The temporomandibular joint (TMJ) is a
diarthrodial synovial joint of the hinge variety
between the head of the mandibular condyle and
the glenoid fossa on the cranial base.
Translational (upper joint space) and rotational
(lower joint space) movements
(ginglymoarthrodial) occur within the joint and
allow for protrusion/retrusion,
depression/elevation and lateral excursion
movements of the mandible'. The type
(rotational, anterior translation, posterior
translation, and mediolateral translation) and
range of condylar movement within the TMJ is
controlled by both active and passive forces,
which include muscles, nerves and biomechanical
constraints in the dentition as well as the TMJ
with its associated ligaments.
In certain conditions, the condylar head is
displaced beyond the glenoid fossa in either an
anterior, posterior, medial, lateral, or
superior direction. This is referred to as
dislocation, and it may be partial (subluxation)
or complete (luxation or true dislocation)'.
Subluxation is self reducible by the patient,
while in cases of luxation, the patient requires
assistance in restoring the normal joint
position of the condylar head of the
mandible
Dislocation of the mandibular condyle
represents 3% of all reported dislocated joints
in the body' and has been variously classified
based on symmetry (unilateral or bilateral),
position (anterior, posterior, medial, lateral,
and superior), number of occurrences (recurrent
or non-recurrent), time of presentation (acute
or chronic), and etiology (traumatic and
non-traumatic or spontaneous). However, anterior
dislocation is the most common type seen in
clinical practice.
Individuals in the second and third decades
of life appear to be more predisposed to this
condition , though TMJ dislocation has been
reported in children and the elderly. Women are
more likely to develop TMJ dislocation , but the
reason for this female predisposition is not yet
fully understood.
The occurrence of TMJ dislocation has been
noted in different clinical and everyday
situations such as laughing, shouting, yawning,
eating, epileptic and eclamptic fits, tooth
brushing, vomiting, trauma, gastroendoscopy,
general anesthesia, otorhinolaryngological and
dental procedures, and transesophageal
echocardiography.
Different treatment modalities, both
conservative and surgical, have been used to
manage TMJ dislocation with varying success
rates. Although many studies have been conducted
on TAU dislocation, very few have been done in
resource depleted environment. The aim of this
retrospective study is to highlight the pattern
of presentation of TMJ dislocation and the
treatment modalities commonly used in our
environment.
IV. Discussion
TMJ dislocation has been documented in
varying age groups. In the present study, a high
incidence of TMJ dislocation was noted between
the third and fifth decades of life. This result
was similar to other findings. The peak age
group incidence was 40-49 years. In contrast,
other studies have reported a peak age group
incidence of 20-29 years and 70-79 years.
More males than females presented with TMJ
dislocation, which was similar to some other
findings. However, some studies have documented
a female preponderance. This difference may be
related to the cultural and religious beliefs of
the people in the area where this study was
conducted. They are predominantly Muslims;
therefore, women are more restricted in line
with the Sharia legal system. As a result, some
cases of TMJ dislocations may not present to the
hospital for treatment, especially in female
patients.
Based on the United Kingdom National
Socio-economic Classification (2010), most of
the patients (83.4%) whose occupational status
was documented belonged to analytical class 8,
and 30% of these were students. Despite this
observed association between low social class
and TMJ dislocation, there was no statistically
significant relationship between the two
variables. Previous studies did not include
information regarding the social status of the
patients.
The interval between the occurrence of the
dislocation and the patient's presentation at
the clinic ranged between 1-720 days with a mean
of 51.7 days. Acute TAU dislocations were more
common (46.2%), although a higher percentage of
patients presented with chronic TAU dislocation
when compared to previous findings. Factors
responsible for late presentations in our
environment included cultural and religious
beliefs (attributing TMJ dislocation to
spiritual events), financial constraints (most
of those affected were of low socioeconomic
class), missed diagnoses by other medical
practitioners, and a shortage of skilled
healthcare professionals. In some cases,
patients had to travel a distance of over 300 km
to seek treatment.
Similar to other studies, yawning was
the most common etiological factor for TMJ
dislocation amongst our patients (50.0%).
However, another report cited trauma as the most
frequent cause. The pathophysiology of
yawning as it relates to TMJ dislocation
is not fully understood. It is likely that
repeated yawning (especially forceful
yawning) leads to a gradual laxity of the
restraining joint ligaments over time, thus
predisposing such individuals to an increased
range of condylar movement.
Systemic conditions such as myotonia
dystrophy, Parkinson disease, multiple
sclerosis, cerebral palsy, and psychiatric
disorders are associated with an increased risk
for TMJ dislocation. Three of the patients in
this study had known psychiatric conditions and
were on antipsychotic agents. Documentation of
TAU dislocation in psychiatric patients exists
in the literature and often occurs following
drug-induced orofacial dystonic reactions, which
commonly result from the use of
anti-dopaminergic agents. Dislocation may occur
with any antipsychotic agent, although previous
reports have implicated haloperidol, thiotixene,
risperidone, and aripiprazole. One of the
patients in this study was on risperidone.
However, dystonic reactions may occur with other
nonantipsychotic agents with antidopaminergic
activity, such as antiemetics
(metochlopromide).
The diagnosis of TMJ dislocation is mainly
clinical; however, different imaging modalities
can assist in patient assessment, treatment
planning and follow-up. Plain radiography
(specifically left and right oblique views of
the jaws) was the only imaging modality used to
assess the patients in this study because it is
cheap and widely available at most centers.
Trans-cranial oblique views of the TMJ, contrast
computed tomography scans, i-CAT scans (Imaging
Sciences International, Philadelphia, PA, USA),
magnetic resonance imaging, linear and
rotational plain tomograms, TAU arthroscopy, and
the Dolphin imaging system (Dolphin Imaging and
Management Solutions, Chatsworth, CA, USA) are
other imaging modalities that can be used in
patient assessment.
Both surgical and non-surgical methods have
been used in the treatment of TAU dislocation.
Although surgical treatment is usually
undertaken when conservative options have
failed, no strict criteria exist in the
literature for the use of any of the various
conservative and surgical treatment options.
Non-surgical treatment may be initiated with or
without local or general anesthesia and also
with or without intermaxillary fixation.
Non-surgical treatment in acute TAU dislocation
involves manual reduction using the Hippocratic,
wrist pivot or extra oral techniques or a
combination of these technique?. Similarly,
manual reduction in acute TMJ dislocation using
a bone hook has been reported. Manual reduction
was successful in 13 (59.1%) of our patients,
which was a higher success rate than the 27.6%
reported by another study. This difference in
the success rate may be related to the fact that
most patients in our study presented with acute
dislocation, while that previous study primarily
included those with chronic dislocation.
In the chronic form of TAU dislocation,
manual reduction, reduction using a Bristlow
elevator or a bone hook, and bite block traction
are some of the non-surgical methods available'.
Bite block traction was used successfully in six
(66.7%) of nine patients managed for chronic TAU
dislocation in our study. This percentage was
higher than the 54,5% success rate reported by a
previous study. Bite block traction is a good
alternative for patients in whom surgery with
general anesthesia carries a high risk; it is
also inexpensive and prevents further
deterioration of the patient's condition while
waiting for a surgical slot to open up 22.
However, this type of traction is time
consuming, can be associated with severe pain,
may lead to tooth/teeth mobility, and carries a
risk of wire injury to the surgeon or the
patient. Non-surgical methods have also been
used in the management of recurrent TAU
dislocation to prevent future dislocation,
including autologous blood injection, injection
of botulinum toxin A and Picibanil (Chugai
Pharmaceutical Co., Ltd., Tokyo, Japan)
injection.
Surgical treatment is used in both acute (in
cases of superior dislocations into the middle
cranial fossa) and chronic (or recurrent) TAU
dislocations and may involve endoscopic
procedures or open surgery. Surgical methods
range from those that create a new joint or
change the axis of rotation of the TAU
(condylectomy, inverted L-shaped osteotomy,
vertical subsigmoid osteotomy, or oblique
subsigmoid osteotomy) to procedures that aid in
the reduction of a dislocated condyle or prevent
redislocation after reduction (temporalis muscle
myotomy, eminectomy, Dautrey's procedure, or
augmentation of the articular eminence). Three
patients (13.6%) in this study received surgical
treatment: an inverted L-shaped osteotomy in two
patients and a vertical subsigmoid osteotomy in
one patient. The low rate of surgical
intervention in this study was a result of our
successful treatment of the dislocation with
conservative measures.
Patient compliance with postoperative
follow-up review was poor and may be related to
financial constraints and a feeling of being
healed. However, three patients presented with
complications after treatment: an anterior open
bite in two of the patients managed surgically,
and Ellis class I mobility of the maxillary
incisors in one patient treated using bite block
traction.
V. Conclusion
In this study, male sex, middle age,
yawning, and low socioeconomic status
appeared to be associated with TAU dislocation;
however, this observed relationship was not
statistically significant. Although different
treatment modalities exist in the literature,
this study further highlighted the effectiveness
and advantages of conservative methods of
treatment.
