This document discusses the pneumatic system of the temporal bone, specifically: 1. It describes classifications of pneumatization from extensively to non-pneumatized. 2. Surgical techniques like canal wall up vs. canal wall down mastoidectomy are chosen based on pneumatization. More pneumatized ears are suitable for canal wall up. 3. Theories on pneumatization include both hereditary and environmental factors influencing development. Middle ear disease in childhood may impact future pneumatization.

1. The Pneumatic System of the Temporal
Bone
Dr surbhi
Patna medical college

2. • refers to the extent of air cells.
• extensively pneumatized, well pneumatized,
fairly and poorly pneumatized ears,
nonpneumatized or sclerotic ears.

3. Understanding pneumatization
1. Surgical-anatomical reasons.
variations of the air cell tracts, their location,
extensions, and how they connect with each
other.
2. The choice of surgical technique-influences
the surgeon in the choice of whether to
perform cwu or cwd

4. • In well-pneumatized ears, canal wall- up
mastoidectomy is considered, and in poorly
pneumatized ears, canal wall-down
mastoidectomy is considered

5. • 3. Enlargement of the cavity-perform canal
wall- up mastoidectomy and enlarge the
mastoid cavity in order to improve the
ventilation of the middle ear.

6. • The supporters of the genetic theory claim
that a large cavity has a buffering effect on the
changes in middle ear pressure caused by
poor tubal function

7. Several arguments suggest the
opposite effect.
• Children with a history of secretory otitis
media at the age of four or five, but with
normal hearing, ear drum, and tubal function
at the age of 12, have not gone on to develop
retraction for as long as they have been
followed , even if their mastoid air cell system
was small

8. • B. Ears with otosclerosis that have undergone
fenestration, eliminating the antrum and the
mastoid process and converting them into an
open cavity, have not developed retraction of
the drum, even many years after surgery,
indicating that the missing pneumatic system
did not result in retraction of the normal
drum.

9. • C. The spontaneous or surgically created
atticoantrotomy with exenteration of the
antrum and mastoid cells does not necessarily
lead to retraction of the pars tensa due to
elimination of the mastoid process.

10. Hereditary and Environmental
Pneumatization Theories

11. • Wittmaack's endodermal theory , normal
middle ear mucosa is a prerequisite for the
normal pneumatization process
• Middle ear diseases in infancy and early
childhood are thus the cause of the reduced
pneumatization-environmental theory by
neo-Wittmaackians"

12. • Diamant's theory- otitis media is a result of
reduced pneumatization.

13. • The mucous glands were definitely
pathological.

14. • pneumatization process is taking place, is
exposed to pathological stimuli of various
degrees of severity and duration.
• These stimuli may have a considerable effect
on the process of pneumatization,
• large variation in the size of the cellular
system.

15. The Size of Air Cells and Previous
Disease
• Significantly, the largest air cell systems were
found in children with no previous disease
• Grommets

16. THE PNEUMATIZATION PROCESS
• At birth, the entire tympanic cavity is filled with
air, with the antrum still partly filled with
mesenchyme.
• The pneumatization of the mastoid process starts
at birth with the development of the periantral
cells, and continues through early childhood
toward the mastoid tip.
• From the antrum, pneumatization continues
toward the labyrinth and the apex of the pyramid

17. • At puberty, the last part of the petrous bone is
pneumatized.

18. The pneumatization process of the air cells
• 1) Lacunar resorption
• 2) Invasion of fibrous
• 3) Disappearance of the fibrous tissue

19. Mastoid Air Cells
• antrum is the site of origin of the mastoid air
cells
• the first to develop are the periantral and
tegmental cells, as well as the central mastoid
cells.

26. Clinical Importance of Cell Tract
Connections
• 1. From the hypotympanum via the IL and RL
cells
• This route would seem to be the simplest and
most direct way.

27. • 2. From the hypotympanum via the
precochlear cells, apical cells, and
infralabyrinthine cells, and then to the
mastoid cells
• 3. from the hypotympanum via precochlear
cells, apical cells, supralabyrinthine or
retrolabyrinthine cells toward the mastoid air
cells

28. •thankyou