15.2.5 Cysts
MUCOCELES
The peak incidence of mucoceles is in the second decade of life; however, they are
not uncommon in younger children (1011HFig. 15.7) including neonates. Mucoceles are
caused by trauma to minor salivary glands or ducts and are often located on the lower
lip. They are the commonest non-infective cause of salivary gland swelling in
children. Salivary tumours are rare in this age group.
RANULA
This appears as a bluish swelling of the floor of the mouth (1012HFig. 15.8). It is essentially
a large mucocele. It may arise from part of the sublingual salivary gland.
BOHN'S NODULES
These gingival cysts arise from remnants of the dental lamina. They are found in
Neonates. They usually disappear spontaneously in the early months of life.
EPSTEIN'S PEARLS
These small cystic lesions are located along the palatal mid-line. They are thought to
arise from trapped epithelium in the palatal raphe. They are present in about 80% of
neonates and disappear within a few weeks of birth.
DERMOID CYSTS
These are rare lesions of the floor of the mouth. They appear as intraoral and
submental swellings (1013HFig. 15.9). They are derived from epithelial remnants remaining
from fusion of the mandibular processes.
LYMPHOEPITHELIAL CYST
In the past this was termed branchial arch cyst as it was thought to arise from
epithelial remnants of a branchial arch. They are normally found in the sternomastoid
region, although they can present in the floor of the mouth. Histologically the cyst
wall contains lymph tissue. The tissue of origin is thought to be salivary epithelium.
THYROGLOSSAL CYST
This cyst, which arises from the thyroglossal duct epithelium, may present intraorally.
The mouth however, is a rare site. Most arise in the region of the hyoid bone.
1014H
Fig. 15.7 Bilateral mucoceles in a 3-
year-old girl. (By kind permission of the
Journal of Dentistry for Children.)1015H
Fig. 15.8 A ranula in a 14-year-old