MAXILLARY SINUS

PRESENTATION BY : Huma Javeriya

Maxillary Sinus The maxillary sinus is

the pneumatic space that is lodged inside the body of the maxilla.

It communicates with the environment by the way of the Middle nasal meatus and the Nasal vestibule.

It is one of the paranasal sinuses.

ANTRUM OF HIGHMORE

Paranasal sinuses – Air containing bony spaces

present around the nasal cavity.

– Usually lined by respiratory mucus membrane .

– Four paired FRONTAL SINUS SPHENOIDAL SINUS ETHMOIDAL SINUS MAXILLARY SINUS

DEVELOPMENTAL ASPECTSFirst sinus to developInitial development of sinus follows number of

morphogenic events in differentiation of nasal cavity

Horizontal shift of palatal shelves and subsequent fusion with one another.

Nasal septum separates Oral cavity from nasal chambers

Expansion of lateral nasal wall and 3 walls begin to fold

3 Nasal conchae & 3 meatus

Superior & inferior- Shallow depression for half of IU Life

Middle- Expansion in lateral wall and in inferior direction

0-3 ye

ars

•Ovoid appearance•7 mm x 4mm x 4mm volume 6-8 ml •5th month - pneumatization•20th month – posterior development •3rd year – ½ adult size

3-4 ye

ars

•↑ in width with facial growth •Position; 2nd deciduous molars and crypts of 1st permanent molars•Prone to infections

7-9 ye

ars

•Dimensions 27 mm x 18 mm x 17 mm •Growth corresponding to permanent teeth eruption•Canine present as ridge in anterior surface of sinus

9-12 ye

ars

•Antral floor same level with nasal floor•Portions of alveolar process vacated become pneumatized•Assumes pyramidal shape

12-15

years

•Floor of sinus 5–12.5 mm below nasal floor •Dimensions 32-34 mm x 28-33 mm x 23-25 mm•Volume 15-20 ml•Floor i.r.t 1st and 2nd molars and 2nd premolar

Old age

•Resorption of ridge – thinning of sinus wall •Extension of sinus till crest•Anterior & infratemporal surface reverts to infantile condition

Developmental anomalies1. Agenesis : complete absence of

maxillary sinus2. Aplasia : incomplete formation.

Developmental anomalies3. Hypoplasia : failure to develop to

normal size4. Supernumary maxillary

sinus : more than the usual number.

Microscopic anatomy• 3 layers

– Epithelium– Basal lamina– Sub epithelium

Epithelium• Pseudostratified ciliated columnar epithelium • Cells

– Columnar ciliated – Goblet – Basal– Non – ciliated

Ciliated epithelium

Ciliated epithelium• 100 motile and no. of immotile microvilli present

along apical surface• Function: mucus clearance along with entrapped

debris from nose and PNS• Ciliary motility dependent on ATP driven molecular

motors cause outer doublets of axoneme to slide over each other

• All cilia beat together to form metachronous wave• Each cilia has power stroke followed by recovery

stroke

Microvilli• Hair like projection of

actin filament • Length 1-2 mm • Function:

– Increase surface area of cell

– Prevent drying of surface

Goblet cells• Goblet cells are modified simple columnar

epithelial cells, having a height of four times that of their width.

• Function is to secrete gel-forming mucins, the major components of mucus

The cytoplasm of goblet cells tends to be displaced toward the basal end of the cell body by the large mucin granules, which accumulate near the apical surface of the cell along the Golgi apparatus, which lies between the granules and the nucleus.

Goblet cells are found scattered among the epithelial lining of organs

Physiologic nature of mucus layer• Sino nasal epithelium covered by mucus blanket • Traps particles>0.5-1 um• Composition

– Water (95%)– Others (5 %)

• Peptides• Salts• Debris

• Ph = 5.5-6.5

Physiologic nature of mucus layer

2 layersInner sol

- Continuous - Low viscosity

- Surrounds shafts of cilia

Outer gel-Discontinuous- High viscosity

-Along ciliary tips

Basal lamina & subepithelium• Contains serous glands and blood vessels• Subepithelium – 10 serous• Mucosa removal – 73% decrease in serous

glands and 30% in goblet cells

Functions of sinus1. Decrease skull weight2. Impart resonance to voice3. Mucus production and storage4. Humidify and warm inhaled air5. Define facial contour6. Immunodefensive action7. Conserve heat from nasal fossae8. Moisturize air9. Filters debris10. Dampen pressure differential during inspiration11. Limit extent of facial injury from trauma12. Serves as accessory olfactory organ

Importance for Dentists• There is a close proximity

between the roots of maxillary 2nd premolars and the 1st molars and the sinus floor.

• Infections in the periapical area of this teeth erodes the already thin bone in this region.

• It spreads to the sinus causing sinusitis.

• And in this process causes a communication between the oral and the nasal cavity which is known as oroantral fistula

Maxillary sinusitis• Group of diseases mainly

inflammation & infection which affect the nasal mucosa and Para Nasal Sinus.

Maxillary sinusitis

CAUSES

• 1. Infectious causes• a) Bacterial • b) Viral • c) Fungal• d) Parasitic• 2. Non infectious causes• a) Allergic• b) Non allergic• c) Pharmocologic • d) Irritants• 3. Disruption of mucociliary drainage• a) Surgery• b) Infection• c) Trauma

MAXILLARY SINUSITIS• Antral lavage

Oroantral fistula

Acute Chronic1. Escape of air and fluids through nose & mouth

1.Pain, tenderness over cheeks

2. Epistaxis 2. Purulent discharge

3. Excruciating pain 3. Post nasal drip

4. Altered voice 4. Presence of polyps

Common in males. Immediate sign:

Displaced root /tooth

Oroantral fistula• Management

• 3mm-5mm heals spontaneously• Acute OAF: closure by simple reduction of buccal and

palatal socket walls, followed by acrylic splint.

• Thank u