by: y J. Vitagliana, L.A. Norton, L.A. Assael
University of Connecticut School of Dental Medicine Farmington, CT 06030
Ehlers-Danlos syndrome (EDS) is an unusual syndrome affecting many
organ systems and tissue functions through the expression of defective
collagen. Although simply stated as a defect in collagen, these
disorders are extremely heterogeneous expressing many subtypes. At the
molecular level, a variety of defects occur, varying from mutations
involving the genes that produce collagen, to those involving the
enzymes that are responsible for post-transcriptional modifications of
m-RNA. These various molecular lesions result in the expression of EDS
as a clinically heterogeneous disorder with several patterns of
inheritance. Thus the clinical expression of these syndromes is
variable and difficult to recognize.
The most common subtypes of EDS are types I, II, and III. These
three are inherited as an autosomal dominant disease. The hallmark of
EDS type I is the hyperelasticity and soft velvety texture of the skin
that is fragile and bruises easily. Generalized joint instability is
another marked feature of EDS type I. This encompasses recurrent
dislocations of all major joints with potential to develop fragile
vessel walls. Hematomas frequently encountered are a result of weakened
vascular walls. A patient may complain of muscular cramps due to
muscular hypotonia and weakness secondary to orthopedic stresses. Type
II is reminiscent of type I, yet clinical symptomatology is less
severe. Skin hyperelasticity, skin laceration, scarring and bruising
are mild to moderate in severity. Type III, according to Fialkow, is
the most common form of EDS. The remarkable feature is gross
hypermobility in all joints. Patients afflicted with type III may
demonstrate hyperelastic tissue sketching without undue stress. Other
dermatological considerations of EDS are mild. Type IV, also known as
ecchymotic type, has little evidence of skin hyperelasticity and joint
hypermobility. A type III collagen defect is responsible for the marked
skin fragility and easy bruisability. Mitral valve prolapse is
prevalent as it is in types I and II. Type V, the only X-linked type of
EDS, is characterized by musculoskeletal disorders, with little skin
and joint symptoms. Type VI, ocular type, is characterized by fragility
of the eye, cornea, and sclera, with pronounced skin and joint
fragility. Type VII is characterized by patients with very short
stature, with decided joint hypermobility and dislocations. Type VIII
patientâ€™s major complication is fragile skin and advanced periodontal
disease. These patients often lose their teeth at a very early age.
Many dental manifestations of EDS have been documented. These should
be taken into account when treating the dental patients with EDS. The
most common of these findings include hypermobile temporomandibular
joints (TMJ), a high incidence of TMJ dislocation, fragile oral mucosa,
severe susceptibility to periodontitis, predilection for enamel
fractures, pulp stones, tooth mobility and difficulties with
orthodontic retention. All aspects of dental treatment should be
modified according to the EDS pathologic expression and risk.
EDS patients need routine dental care. The purpose of this study was
to identify the problems in treating the EDS populationâ€™s dental
needs. In our attempt to address these considerations, we performed a
small study that compared a group of EDS patientâ€™s orthodontic
experience with those of a control sample of non EDS orthodontic
patients. In addition, an assessment of temporomandibular disorders
(TMD) was made on both groups.
Material and Methods:
The data were collected through a mailed survey which was sent to
members of the Ehlers-Danlos National Foundation (EDNF). The EDNF
provides support and updated information to those who suffer from the
disorder and serves as a vital information link to and from the medical
and dental community. Loose Connections, (volume 8) the EDNF
publication, was used to distribute our survey. Although all members of
EDNF were sent the questionnaire, the responses to our survey were few,
totaling 57. In order to make comparisons, we did a similar study on 35
patients taken from a random sample of patients from private
orthodontic practices. The questionnaire was made of two sections, one
section filled out by the patient, the other by the practitioner. The
survey included yes and no questions, and scales of frequency for
certain dental symptoms. The control group questionnaire was an
abridged version of the EDS patientâ€™s questionnaires.
Of the sample reported, there were 22.8% type I, 7% type II, 35.1% type
III, 3.5% type IV, 1.8% type VI, 5.3% type VIII, 11.8% type IX, and
22.8% of unknown type. Types I, II, and VIII had the highest percentage
of patients who experienced difficult orthodontic treatment. 30.8%,
35%, and 100% respectively. 35.1% of the EDS population found their
treatment to be easy, 33.3% tolerable, and 31.6% difficult. In the
control sample none of the patients found their dental experience to be
difficult, and the percentages were almost equally split between
tolerable and easy. Length of orthodontic treatment time for all EDS
groups were consistent with the control group. Unfortunately, more
complex problems take more time to treat and a comparison based on this
information may be of limited value. However, the probability of rapid
relapse necessitates the need for life long retention. The frequency of
dislocation and subluxation of the temporomandibular joint for the EDS
population was much higher than the control groups. 47.4% of the EDS
population experienced some sort of TMJ symptoms while none of the
control group experienced these similar dislocations. EDS types I and
II experienced high rates of jaw dislocation at 84.6% and 100%
respectively. Type III experienced a slightly lower incidence of jaw
Previous studies have shown that the oral findings in EDS play a
significant role in treating these patients. The high frequency of TMJ
subluxation is a major concern when dealing with these patients.
Obviously, caution must be taken in performing any type of dental
procedure, especially those requiring the patients to have their mouths
open for long periods of time. The TMJ often demonstrates profound
laxity in conjunction with generalized joint mobility and dislocation
in these patients. Genetically defective collagen biosynthesis directly
affects the fibrous stability of the retrodiscal tissues, thus causing
recurrent subluxation. Recurrent subluxation was described by Goodman
and Allison. The modality that is described is that of reducible,
anteriorly displaced disk with an overlying neuromuscular component.
Thexton et al reported similar clinical findings of "recurrent" yet
"easily reducible dislocations" which disappeared as "the joints grew
older with age". Joint disturbances are often secondary to laxity in
joint tendons and ligaments. Current therapy for these symptoms
includes occlusal splints, anti-inflammatory agents, muscle relaxants,
and physical therapy. Temporomandibular joint surgery is sometimes
indicated to control subluxation.
The periodontal status in the patients also needs to be closely
monitored both clinically and radiographically in these patients. These
tissues are very prone to gingivitis, periodontitis, and severe
bleeding after invasive procedures. The oral mucosaâ€™s fragility, ease
of bruising, and delayed wound healing also places limitations on
dental treatment. Endodontic brackets, although highly polished and
smooth to the touch, have sharp edges or have stainless steel ligatures
and complex spring mechanisms which can abrade mucosal tissue.
Orthodontic appliances should be smooth and relatively simple in design
to prevent abrasion of the tongue and mucosa. Considerations of moment
to force ratios, rate of bone resorption, tooth mobility and remodeling
time are also important factors in treating these patients. Because of
the problem with tissue repair (slow healing after extraction, slow
forming new bone) suboptimal tissue responses should be expected.
There are special considerations in treating the EDS dental
patient. Our data shows that dental findings greatly vary among the EDS
groups. EDS patients exhibit a high incidence of TMJ dislocation and a
high incidence of TMD related pain and noise, particularly among those
with types I and II. Orthodontic treatment is not shown to be different
in length of treatment, but the experience of dental treatment appears
to be more difficult in EDS patients. Whether it be TMJ symptoms or
periodontal disease, there is a pronounced difference between the
treatment concerns for an EDS patient and that of the rest of the
population. Patients diagnosed with EDS type I and II should be treated
with special care. Each type of EDS has characteristic dental
manifestations which affect orthodontic treatment. The dental
profession should recognize the dentofacial implications of EDS and
provide the appropriate information and maintenance for these patients.
Conservative treatment is certainly desirable. Proper management of
these patients should strive to provide comfort while living with the
We thank the EDNF for their cooperation and help.
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