Numerous writers have investigated the etiology of tori, but no
consensus has emerged yet. Some of the speculated causes include
genetics, environmental factors, masticatory hyperfunction and continued
growth.3-6
Torus palatinus (TP) and torus mandibularis (TM) tori prevalence varies
with sample population, ranging from 0.4% to 66.5% and 0.5% to
63.4%, respectively. Racial differences seem to be considerable with a
significant prevalence among Asian and Eskimo
communities.7,8 There have also been reports of
gender-specific variations in tori prevalence. The majority of authors
asserted that while TM presented more in men than women, TP mostly
prevailed in women.9Table 2 provides a summary of some
of the theories and mechanisms that might be involved in their
formation.
Alveolar bone exostoses (ABE), also known as buttress bone formations,
are benign, isolated, convex outgrowths of the buccal or lingual bone
that may be distinguished from the surrounding cortical
plate.6
Glickman and Smulow35 distinguished between two
categories of buccal alveolar bone enlargement: exostosis and lipping.
Exostoses were described as harmless, isolated, convex outgrowths of the
buccal or lingual bone that could be distinguished from the cortical
plate around them. On the contrary, identifiable thickenings in the
alveolar bone at the direct crestal edge were referred to as buccal
lippings.6
ABE are multiple bony nodules that are found less often than tori. In
contrast, Horning et al.,6 found ABE or lipping to be
present fairly frequently, with 76.9% of all the specimens having at
least one, in a study on 52 skulls with complete dentition.