The document discusses the paranasal sinuses. There are four pairs of paranasal sinuses located around the nasal cavity that develop from invaginations of the nasal cavity mucosa into the bones. The maxillary sinus is the largest sinus and most clinically relevant as it is close to the teeth. Sinusitis is inflammation of the sinuses which can be acute or chronic and is usually caused by infection, trauma, dental issues or tumors. Anatomical relationships between the sinuses and structures like the orbit and teeth are important for dentists to understand.

1. PARANASAL
SINUSES
PRESENTED BY-
DR. SAKSHI SHUKLA
MDS FIRST YEAR 2018
DEPARTMENT OF PUBLIC HEALTH DENTISTR
1

2. CONTENTS
 INTRODUCTION
 DEVELOPMENT
 PARANASAL SINUSES
o FRONTAL SINUS
o MAXILLARY SINUS
o ETHMOIDAL SINUS
o SPHENOIDAL SINUS
 CLINICAL ANATOMY
 CONCLUSION
 REFERENCES
2

3. INTRODUCTION 3
 Air filled spaces
 Open into the nasal cavity
through its lateral wall
 These are- frontal,
maxillary, sphenoidal and
ethmoidal
 Function is to make the
skull lighter, warm up and
humidify the inspired air
and also add resonance to
the voice.

4. PARANASAL SINUSES 4

5. DEVELOPMENT OF SINUSES 5
 At about 25 – 28 weeks of
gestation, three medially directed
projections arise from lateral wall
of nose.
 Between these projections small
lateral diverticula invaginate into
primitive choana to eventually form
meati of nose as beginning of the
development of paranasal sinuses.
 Sinuses begin developing as small
sacculations of mucosa of nasal
meati and recesses.
 As pouches or sacs develop and
grow they will invade the
respective bones to form air sinuses
and cells.

6. 6

7. ` 7
Sinuses have small orifices
(ostia) which open into recesses
(meati) of the nasal cavities.
• Meati are covered by turbinates
(conchae).
• Turbinates consist of bony
shelves surrounded by erectile
soft tissue.
• There are 3 turbinates and 3
meati in each nasal cavity
(superior, middle, and inferior).

8. 8

9. FRONTAL SINUS 9
Lies in the frontal bone deep to the superciliary
arch, extends upwards above medial end of
eyebrow, backward into medial part of roof of the
orbit. Opens into middle meatus of nose into ant.
End of hiatus semilunaris through infundibulum
or frontonasal duct.
 Rudimentary or absent at birth. Well developed between 7 and 8 years.
 Arterial supply- supraorbital artery
 Venous drainage- supraorbital and superior ophthalmic veins.
 Lymphatic drainage- supra mandibular nodes
 Nerve supply-supraorbital nerve

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11. MAXILLARY SINUS 11
 Largest of the paranasal sinuses, first to
develop.
 Pyramidal in shape, base directed
medially towards lateral wall of nose,
apex directed laterally in zygomatic
process of maxilla. Roof is formed by
floor of orbit, floor by alveolar process of
maxilla, Opens into middle meatus of
nose and lower part of hiatus semilunaris.
o Arterial supply- facial, infraorbital and greater palatine
o Venous drainage- facial vein and pterygoid plexus of vein
o Lymphatic drainage- submandibular nodes
o Nerve supply- post. Sup. Alveolar branch of maxillary nerve and middle sup. Alveolar branches from
infraorbital nerve.

12. 12

13. SPHENOIDAL SINUS
 Right and left sphenoidal sinuses lie within the body of sphenoidal bone, separated by
septum.
 Related superiorly to optic chiasma and hypophysis cerebri; laterally to internal carotid
artery and cavernous sinus. Opens into sphenoethmoidal recess of corresponding half of
nasal cavity.
13
Arterial supply- post. Ethmoidal and internal carotid
artery.
Venous drainage- pterygoid venous plexus and
cavernous sinus
Lymphatic drainage- retropharyngeal nodes
Nerve supply- post. Ethmoidal nerve and orbital
branches of pterygopalatine ganglion.

14. ETHMOIDAL SINUSES 14
Numerous small inter-communicating
space which lie within the labyrinth of
the ethmoid bone. Divide into anterior,
middle and posterior
 Ant. Ethmoidal sinus made up of 1
to 12 air cells, opens in ant part of
hiatus semilunaris of the nose
 Middle ethmoidal sinus consist of 7
air cells, opens into middle meatus
of nose.
 Post. Ethmoidal sinus – 1 to 7
aircells , opens into superior meatus
of nose.

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16. CLINICAL ANATOMY 16
o SINUSITIS- infection of a sinus. It
Causes- headache, persistent thick
purulent discharge from nose
o It is of two types acute and chronic
o Maxillary sinusitis most commonly
involved. since drainage of the sinus is
difficult hence it is drained surgically by
either through antrum puncture or
Caldwell-Luc operation.

17. ACUTE SINUSITIS
It is the acute inflammation of the sinus mucosa with severe
pain in sinus area.
17

18. SUBACUTE MAXILLARY SINUSITIS 18
 It is the intermediate stage between
acute and chronic sinusitis. There is
pain only in the form of the local
discomfort.
 Patient has persistent discharge.
 The voice is nasal, throat is sore with
constant irritating cough. Patient can
not sleep well.
 The disease may take a long course
over week or months.

19. CHRONIC SINUSITIS
The term Chronic sinusitis is poorly defined but is best considered as
persistent incompletely resolved acute sinusitis.
19
MMT: Mucous Membrane
Thickening
Ofs: Opacified Frontal Sinus
Oes: Opacified Ethmoid Sinus
Oms: Opacified Maxillary Sinus
M: Mucocoele

20. TREATMENT 20
ACUTE SINUSITIS
1)Drainage is achieved with antibiotics
and nasal decongestants or extraction.
2) Antibiotics
3) Decongestant:Xylometazoline (0.1%)
4) Steam Inhalation : Acts by hydrating
the mucous layer, making it less
viscous and encouraging normal ciliary
clearance of the sinus.
(5) Antral Lavage : Antibiotics and nasal
drops fail, pus must be
removed from the antrum to allow the
sinus mucosa to
recover
CHRONIC SINUSITIS
 Dental origin : Affected teeth
must be removed and the socket
closed surgically as there will be
risk of oroantral fistula.
 Removal of Nasal Polyp
 With presence of Oroantral fistula:
Surgical closure of fistula
Antrostomy: If above all
procedures fails to cure c sinusitis
the inferior meatal Antrostomy
and middle meatal antrostomy can
be done.

21. ODONTOGENIC SINUSITIS 21
 Inflammation of the mucosa of any of
the paranasal sinuses
 Maxillary sinusitis is usually
odontogenic in origin, because of its
close proximity with the maxillary
teeth.
 Cause may be-
o infection- periapical abscess
o Allergy
o Trauma
o Displaced tooth or root
o neoplasm

22. OROANTRAL COMMUNICATION AND FISTULA 22
 An oroantral perforation is an unnatural communication between the oral cavity
and maxillary sinus
 An oroantral fistula is an epithelialized, pathological, unnatural communication
between these two cavities.
can be mainly due to-
 extraction
 Periapical lesions
 Trauma
 Chronic infections of maxillary sinus
 During surgery
 Infected maxillary implant denture teratomatous
destruction of maxilla


23. 23

24. 24Treatment - Cases where oroantral
communication is recent and formation of
fistula is not established.
o Immediate surgery repair to achieve primary
closure
o Simultaneous antibiotic prophylaxis to
prevent sinus infection
Cases seen more than 24 hours after accident:- It is
preferable to defer the surgical closure until the gingival
edges of the fistula have healed soundly (approx 3
weeks)
- Supportive measures should be given
- Maxillary sinus should be gently irrigated with warm
normal saline, if there is purulent discharge or signs of
acute or chronic sinusitis is seen.
• Cases of long duration(more than a
month):
- Surgical closure is required

25. ANTROLITHS IN MAXILLARY SINUS 25
Antroliths are calcified
masses found in the maxillary
sinus.
• There is calcification of
masses of stagnant mucus in
site of previous
inflammation, root fragments
or bone chips.
• Asymptomatic but if continue
to grow patient complain of blood
stain nasal discharge or facial
pain.
• Removal if it is symptomatic

26. ODONTOGENIC CYST LESIONS 26
Odontogenic cysts
are the most common
group of extrinsic
lesions that encroach
on the maxillary
sinuses.
• The cyst enlarges ,the
sinus decrease in size
• The result is radioopaque
line between
the cyst and the air
space of the sinus.

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28. CARCINOMA 28
Carcinoma of maxillary sinus
arises from mucosal lining ,
symptoms depend on direction of
growth-
o Proptosis or diplopia
o Bulging or ulceration of palate
o Swelling of the face
o Pain
o Nasal obstruction, epixtasis,
epiphora

29. BENIGN TUMOR 29
Benign tumors in the sinus may arise from the
lining as polyps and
papillomas, from bone as osteoma or from
maxillary teeth as
odontomes.

30. MALIGNANT TUMOR 30
Squamous cell carcinoma is
the most common malignant
tumor of the paranasal
sinuses.

31. DEVELOPMENTALANOMALIES 31
• Crouzon syndrome : Early synostosis (fusion) of
sutures produces hypoplasia of the maxilla and
therefore the maxillary sinus together with the high
arched palate.
• Treacher Collins syndrome : Associated with grossly and
symmetrically underdeveloped maxillary sinuses
and Malar bones.
• Binder syndrome : Hypoplasia of middle third of the face
with smaller maxillary length and maxillary
sinus hypoplasia.

32. CONCLUSION 32
Paranasal Sinuses (PNS) are air containing bony spaces around
the nasal cavity. There are 4 pairs of paranasal
sinuses(bilaterally) but maxillary sinus is considered most
important to dentists due to close proximity of maxillary sinus
to orbit, alveolar ridge, diseases involving these structures may
produce confusing symptoms. Hence a precise information
about the surgical anatomy is essential to dental practitioners.
the close anatomical relationship of the maxillary sinus and the
roots of maxillary molars, premolars and in some instances
canines, can also lead to several endodontic complications.
Clinicians must be particularly cautious when performing
dental procedures involving the maxillary posterior teeth.

33. REFERENCES
 Malik N. A. Textbook Of Oral And Maxillofacial Surgery,Jaypee Brothers Medical
Publishers Ltd ;( 4th Edition)2015
 Chaurasia B. D. Human Anatomy, CBS publishers and distributers(7th edition)
vol.3,2015
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