FUTURE OFDENTISTRY
SALIVARY GLAND DISEASES
Saliva modulates oral microbial ecosystems, aids
in the preparation of the food bolus, lubricates oral
tissues, and supports other critical oral functions.
The initial phases of dental caries development are
reversed in part by saliva, which buffers acids and is
supersaturated with calcium and phosphorus. The
salivary mucins are a heterogeneous population of
glycoproteins that bathe and protect oral soft tissues
(Schenkels et al, 1995). Salivary glands are a part of
the mucosal immune system.
Salivary Dysfunction
Decreased salivation results in decreased secretion
of antimicrobial and antifungal proteins such as
salivary IgA, lysozyme, lactoferrin, peroxidases, and
histatins (Atkinson and Fox, 1992). Individuals
with inadequate salivary function are at risk for
rampant dental decay, recurrent mucosal candidiasis
and salivary gland infections, esophageal disease,
gastric reflux, altered nutritional intake, and a
decreased quality of life.
The most pronounced salivary dysfunction occurs
in three groups of patients:
u Patients with SjØgren's syndrome, a systemic
autoimmune disorder primarily affecting the sali-
vary and lacrimal glands.
Current prevalence estimates for SjØgren's syn-
drome, using the European Community criteria,
range from 0.6% to 3.3% of the adult population
(Dafni et al, 1997; and Thomas et al, 1998), but
the diagnostic criteria used in these studies are
not accepted universally. International re-
searchers primarily use one of three sets of crite-
ria to select patients for studies (Fox, 1997). This
lack of uniformity in patient selection represents
a significant barrier to research progress.
Diagnostic uncertainty inhibits genetic studies
and makes it impossible to compare studies of
pathophysiology and therapy.
u Patients who have received therapeutic radiation
to the head and neck.
Radiation treatment of oral and pharyngeal malig-
nancies typically includes salivary tissue within the
field. At doses above 40 Gy, the damage is rapid
and irreversible, and the mechanisms for this unfor-
tunate side effect are not understood.
u Patients taking medications that interfere with
salivary secretory processes, such as signaling pathways.
More than 300 medications can cause oral dry-
ness, and certain classes of medications are more
likely to inhibit salivation and cause xerostomia.
These include sedatives, antipsychotics, antide-
pressants, antihistamines and certain anti-hyper-
tensive agents. Medi-cations with anticholinergic
activity can potentially decrease salivation
(Atkinson and Fox, 1992).Diagnosis, Prevention, and Treatment of
Salivary DysfunctionWhen evaluating a patient, the dentist should
consider the patient's medical, dental, and social
histories to identify medications and predisposing
conditions. A history of past radiation therapy,
both internal and external, is important. The
diagnosis of SjØgren's syndrome is usually estab-
lished by a complete ophthalmological examina-
tion, a minor salivary gland biopsy and tests for
serum autoantibodies.
Any patient with salivary gland dysfunction
will benefit from an aggressive oral hygiene pro-
gram that includes the use of topical fluorides
(Ripa, 1989). Other prevention strategies could
include the use of remineralization dentrifices,
which currently are under evaluation in postradi-
ation patients (Papas et al, 1999). Radiation
damage to salivary glands can be limited by
preradiation planning (conformal and static,
multisegmental intensity modulated radiotherapy,
IMRT) that spares as much salivary tissue as pos-
sible from the radiation field (Eisbruch et al,
1999). The use of pilocarpine and the oxygen
radical scavenger amifostine during radiation
treatment may decrease damage to glands (Valdez
et al, 1993; and Jha et al, 2000). Some investiga-
tors are surgically repositioning submandibular
salivary glands to the submental space before
radiation to maintain gland function (Bohuslavizki
et al, 1999).
The availability in the last decade of systemic
agents that can stimulate salivary output
(secretogogues) has been a major advance in
symptomatic management of patients with
salivary gland hypofunction (Fox, 1998);
however, they have significant side effects that
limit their utility and patient acceptance.Dental and Craniofacial Research