Abstract
BACKGROUND: While the mechanism of
aerophagia remains unclear, the frequency of
clenching has been reported to be increased
when under stress. We hypothesized that, via the
swallowing reflex, chronic air swallowing was
induced through a “learned habit” of the oral cavity,
which was acquired through psychological factors.
This study examined whether the habitual repeated
swallowing in the oral cavity was a process of
aerophagia. METHODS: After continuous experimental
saliva swallowing, changes in the stomach
bubble were examined by abdominal X-rays in a
standing position. The subjects included 9 males
and 10 females aged 20 to 36 years that were without
organic disease in the pharynx and nasal cavity.
X-ray images were digitized, and the area of the
stomach bubble was measured by tracing.
RESULTS: A close correlation was revealed in the
stomach bubble area between posteroanterior
and lateral views in six males (p<0.001, r = 0.910).
In 3 males and 10 females, the area of the stomach
bubble by posteroanterior view after 30 swallows
was significantly increased compared with that
before swallowing (p = 0.004). CONCLUSIONS: In
the present study, abdominal X-rays confirmed
that frequent saliva swallowing expanded the
stomach bubble.
