oral histology

1. Maxillary sinus
Dr:mahmoud3mmar
Dr: 0106 39 700 30
f.B: m.3mmar9428@yahoo.com

3. Contents of chapter:-
1- definition
2- anatomy of maxillary sinus.
3- histology of max. sinus.
4- function of max. sinus
5- blood supply , innervation & lymphatic drainage.
6- drainage of sinus.
7- enlargement of sinus.
8- relation between maxillary teeth , sinus.
9- clinical consideration.

4. 1- definition:
it’s the largest bi-lateral air-containing cavity
occupying the body of the maxilla ,
open into the nasal cavity
by a single or multiple opening.
N.B: maxillay sinus varies in size , shape & postion.

5. 2- anatomy of maxillary sinus:-
 its described as a 4 sided pyramid .
1. base located medialy toward the nasal cavite.
2. apex directed laterally toward the body of zygomatic bone.
 The walls of sinus (4 sided pyramid) are related to the surface of
maxilla as follow.
1- anterior wall: to facial surface of
Maxilla (region of canine , premolars).
2- posterior wall: to infra-temporal
surface of maxilla.
3- inferior floor: to alveolar process ,
1 mm below the level of floor of the nose.
4- superior roof: floor of orbit.

6. N.B: the floor of sinus is lateral to hard palate. Thus hard
palate doesn’t enter into the formation of hard palate.

7. 3- histology of maxillary sinus:-
walls of sinus are lined by thin mucos membrane (epith. & C.T)
similar to respiratory type but thinner ,
continuous with that lining the nasal cavity.
 its composed of
psedo-stratified
columner ciliated
epithelium, C.T
layers which are
separated from
bone by
peri-osteal layer.
Thus its form
muco-peri-ostium.
Goblet
cells
Lamina
propria
Epithelium
Mixed
glands

8. A) Epithelial layer:
* its pseudos-tratified columnar ciliated
epithelium rich in goblet cells
* its rested on nearly straight basement membrane..

9. Cilia
site: at free end of most columnar cells.
functions: drainage of sinus.
structure: microtubules .
mechanism of action: provide motile apparatus of sinus
epith. , they beat automatically in direction which move
any substance from interior of the sinus toward the nasal
cavity through its opening.
N.B: cilia beat automatically not under neural control

10. Goblet cells
• Its uni-cellular gland which poures its secretion by rupturing of
apical cell membrane which will aging regenerate ,
the secretion contains parts from apical cytoplasm , apical cell membrane.
• This cell looks like glass with stalk
(apically: head of glass & basally stalk of glass)
swollen apical part: full of mucin
basal end: nucleus is situated

11. B) Lamina propria:
* consist of loose C.T , very few elastic fibers. Mixed glands
* its moderately vascular.
* mixed glands.
* its secretion reaches the
sinus lumen through excretory ducts.
N.B: its separated from epith. Layer
by nearly straight basement membrane &
fused with peri-ostium of underlying bone.

12. 4) Functions of maxillary sinus:-
1- warming , moistening of inhaled air.
2- resonance of voice.
3- producing bacterial lysozyme to nasal cavity.
4- enhancement of facio-cranial growth (pneumatization)
5- lightening of the skull.
6- pressure danpening.
7- increase olfactory surface area.
8- heat insulation of the brain.
9- assisting in regulation of intra-nasal pressure , serum gas
pressure.

13. 5- blood supply , lymphatic drainage & innervation:-
1- blood supply: from nasal mucosa , osseous vasculature of
surrounding structure.
2- lymphatic drainage: lymph vessels pass through the
infra-orbital foramen to the nasal cavity
then into sub-mandibular lymphnode.
3- innervation: nerve supply is derived from branches from
maxillary division of trigeminal nerve

14. 6- drainage of sinus:-
* Maxillary sinus is drained to nasal cavity throught a
perforation into its base ( ostium maxillare ).
* this opening located in lateral wall of nasal cavity
in the middle meatus,
between middle , inferior conchae
in concavity called (hiatus semilunaris)
* this opening varies in size , postion & efficiency in draining the sinus
* accessory ostium may occur in a lower level than the ostium maxillae ,
is slightly more advantageously placed for drainage.

16. Hiatus
Semilunaris

18. 7- enlargement of sinus
Its enlarged by process of pneumatization.
pneumatization: is a process of growth by bone resorption on
internal wall of sinus & bon deposition on outer surface of maxilla
Maxillary sinus extended to many processes :
its extend 1. outward to zygomatic process.
2. inward , upward to frontal process.
3. downward to alveolar process.
 When it extend downward into alveolar process ; the apices of the
roots may appears protruded into the sinus.

19. 8- relation between maxillary teeth , sinus:-
* the teeth which in direct relation to the maxillary sinus is
vary from one individual to another
according to the shape , size of sinus.
* the apices of the roots (specially palatal roots) of first , second
molars are usually near to the floor of the sinus followed by
second , first premolar & canine and third molar respectively.

20. Relationship of the floor of the sinus to the roots of the maxillary teeth

21. 9- clinical consideration.
1- maxillary sinusitis of one side may cause pain in maxillary teeth of the same
side (toothache) , may cause pain like pulp pain.
2- infection of teeth which are close to sinus may cause sunus infection.
3- extraction of first , second molars carry the greatest risk to formation of
fistula (oro-antral comunication) & roots of these teeth may forced into the
sinus.
4- A fractured root may be forced accidentally during surgical manipulation
into the sinus if the bone is thin .
5-true sinus infection increase if the patient bends over , place head below the
knees.
6- sinus may be divided into parts which may interfere with drainage.

22. 1. In pitutary gaintism all sinuses assum a much large volume
than in healthy individuals .
2. Congenital infections (by spirochetes in congenital
syphilis) the pneumatic processes are greatly suppressed,
resulting in small sinuses .
3. Transfer of a pathologic condition from the sinus to
the orodental apparatus , or vice versa by :
- Mechanical connection .
- Way of the blood or lymphatic pathways .

23. 4. Surgical manipulation on upper 1st molar may
damage the sinus (oroantral fistula) .
5. Extraction of hypercemetosed tooth may also lead to a
perforation (radiograph should be considered before
extraction) .
6. Chronic infections of mucoperiosteal layer of the sinus
might involve superior alveolar nerves, and may neuralgia
that mimics possible dental dental origin .

24. 8. Due to vascular connection between the sinus and teeth
by the superior alveolar vessels, bacterial sinusitis may be
followed by some oral manifestation .
9. A fractured root may be forced accidentally during
surgical manipulation into the sinus if the bone is thin .
10. Mlignant lesions of the sinus may produce their
primary manifestation in the maxillary teeth (pain,
loosening, supraeruption, or gingival bleeding) .

25. thanks