School of Dental Medicine - University of Connecticut
Originally published in Loose Connections Vol VIII, No.4 1993

When contemplating orthodontic treatment on a patient with Ehlers-Danlos syndrome (EDS), there are a number of special precautions to be taken. Extreme joint hypermobility in many EDS patients often leads to chronic dislocation of the temporomandibular (jaw) joint. This makes the placement of complex orthodontic appliances very troublesome for the patient and the clinician. In addition, the oral surgeon must be extra cautious to prevent a dislocation of the mandibular condyles (lower jaw joint) when performing a surgical procedure in preparation for orthodontics. Because of tissue repair problems in EDS, there may be slow healing after dental extractions, followed by soft tissue scarring. The orthodontic appliance used on an EDS patient should be very smooth and relatively simple in design. The oral mucosa, or mouth lining tissues, are very fragile, liable to injury and particularly vulnerable to sharp objects such as orthodontic appliances (braces) or partial dentures.

The dental anatomy of the posterior teeth occasionally have high cusps and deep fissures. The roots may be dilacerated, (stunted, bent, fused or twisted in shape). The pulps may become partly obliterated by the pulp stones in the crown portions of the pulp, making root canal treatment difficult. The dentin may have an unusual pattern and abnormal fine structure because of an aberrant collagenous dental crown anatomy. Thus, there may be a right to left or upper dental arch to lower dental arch tooth size discrepancy (difference) making ideal dental interdigitation very difficult. Tooth movement might be expected to be more rapid for for a constant appliance activation because of the collagen cross linkage defect. The mobility of teeth during tooth movement may be greater than normal. This may be caused by stretching, tearing and slow repair of the fibers. Similarly, the gingiva (gums) may be more prone to inflammation and possible recession. There have been reports of early onset of some periodontal defects (gum and tooth support). The old EDS type VIII, which is similar to the Classical type, in particular, is characterized by extreme periodontitis which can be quite debilitating. With the added dental mobility of the teeth, slowed repair processes and poor organization of tooth supporting tissue collagen, the need to wear retainers long after completion of the case may be greater. Although anatomic defects in the root morphology have been described in EDS, the detailed molecular composition of the dentin has not been studied. If changes do exist, root resorption as a side effect of orthodontics could be a problem. This has not been demonstrated clinically, however.

EDS is a connective tissue disorder which may have many effects on the dentition of the patient. With suitable understanding of the underlying disease manifestations and appropriate precautions by the orthodontist, orthodontic treatment can be accomplished with the minimal undesirable side effects.