Key Points:
- The development of the mastoid cells and paranasal sinuses are
affected by environmental factors, genetic diseases, and previous
infections.
- Due to the similar developmental pattern, close anatomic localization,
and mucosal continuity of the mastoid cells and paranasal sinuses, an
interplay of these structures at the development stage can be
expected.
- There are studies in the literature investigating the relationship
between mastoid cell pneumatizion and paranasal sinus volumes, but
none of them investigate the relation between mastoid pneumatizion and
paranasal sinus volumes in patients with unilateral COM.
- Our study’s attractive finding is that although there is no
statistically significant difference in the maxillary and frontal
sinus volumes, sphenoid sinus volumes were significantly lower at the
affected side of patients with unilateral COM.
- This can be explained by the close neighborhood of the mastoid cells
and the sphenoid sinus and mucosal lining contiguity. Also, delayed
development of the sphenoid sinus in comparison with other sinuses may
increase exposure to various pathological conditions.
Keywords: Chronic otitis media; Cholesteatoma; Paranasal sinus
radiology; Pneumatization
Background
Chronic otitis media (COM) is a disease characterized by the recurrent
and persistent inflammation of the mastoid cavity, middle ear, and
tympanic membrane 1. While the incidence of the
disease is below 1% in the USA, the rates rise to 4% in developing
countries, leading to significant morbidity and mortality2. Even though the etiology and pathophysiology of the
disease are not completely revealed; low socioeconomic status,
inadequate nutrition, passive smoking, insufficient mastoid
pneumatization , and sinonasal diseases have been found pertinent to the
progression of the disease 1,3.
The middle ear, mastoid cells, and paranasal sinuses are the largest
air-filled cells with close anatomic localization in the skull and have
similar embryologic characteristics 4. Both the
paranasal sinuses and the mastoid cells are formed by pneumatization of
the related bones, and their surfaces are lined with the upper
respiratory tract epithelium, which is originated from endoderm. The
development of mastoid cells, maxillary and frontal sinuses start in the
embryological period and continue until puberty 4,5,
while the pneumatization of the sphenoid sinus starts approximately in
the 1st year of life and continue until the end of the
3rd decade 5,6. Due to the similar
developmental pattern, close anatomic localization, and mucosal
continuity of the mastoid cells and paranasal sinuses, an interplay of
these structures at the development stage can be expected.
The association between mastoid pneumatization and COM has been long
investigated, and the relationship between chronic inflammatory middle
ear disease and poor mastoid pneumatization has been shown in several
studies 7,8. Some studies show that sinonasal disease
increases the risk of middle ear disease 3,9,10.
However, to the best of our knowledge, only one radiologic study
investigated the interrelation between the measurements of the paranasal
sinuses and mastoid pneumatization in patients with COM and suggested a
hypothesis that chronic rhinosinusitis during childhood may play a role
in the development of cholesteatoma 11.
Material and Methods