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آية ) البقرة (32سورة

بسم الله الرحمن الرحيم

الله صدق

العظيم

22

BYBYDR. Fawzy DarweeshDR. Fawzy Darweesh

Is the pneumatic space that Is the pneumatic space that is lodged inside the body of is lodged inside the body of the maxilla and that the maxilla and that communicates with the communicates with the environment by the way of environment by the way of the middle nasal meatus and the middle nasal meatus and the nasal vestibules. the nasal vestibules.

1.1. Palate formation. Palate formation.2.2. Expansion and folding of the lateral nasal Expansion and folding of the lateral nasal

wall and 3 nasal conchae and 3 subjacent wall and 3 nasal conchae and 3 subjacent meatuses arise.meatuses arise.

3.3. The inferior and superior meatuses remain The inferior and superior meatuses remain as shallow depressions.as shallow depressions.

4.4. The middle meatus expands into the lateral The middle meatus expands into the lateral nasal wall in an inferior direction into the nasal wall in an inferior direction into the maxillary body.maxillary body.

5.5. The sinus then expands into the maxillry The sinus then expands into the maxillry body as the CRL increases.body as the CRL increases.

6.6. The sinus expands and modify The sinus expands and modify in form until the time of in form until the time of eruption of all permanent teetheruption of all permanent teeth..

7. 7. In the adult the sinus In the adult the sinus measures about measures about 34 mm34 mm in the in the anteropoterior anteropoterior direction , direction , 33 33 mmmm in in superoinferior superoinferior direction , direction , and and 23 mm23 mm in the in the mediolateral mediolateral direction.direction.

NoteNote : :

• The hard palate dose not enter The hard palate dose not enter into the formation of the floor of into the formation of the floor of the sinus. It forms the floor of the sinus. It forms the floor of the nasal fossa. The sinus floor the nasal fossa. The sinus floor is lateral to the hard palate.is lateral to the hard palate.

The sinus is described as a four-sided pyramid ;The sinus is described as a four-sided pyramid ;

- The base: facing medially toward the nasal cavity.- The base: facing medially toward the nasal cavity. - The apex : pointed laterally toward the body of the - The apex : pointed laterally toward the body of the

zygomatic bone. The 4 sides are: zygomatic bone. The 4 sides are:

1. Anterior, to the facial surface of the body.1. Anterior, to the facial surface of the body. 2. Inferior, to the alveolar and zygomatic processes.2. Inferior, to the alveolar and zygomatic processes. 3. Superior , to the orbital surface.3. Superior , to the orbital surface. 4. Posterior, to the infratemporal surface. 4. Posterior, to the infratemporal surface.

The base of the sinus presents a The base of the sinus presents a perforation which named the ostium perforation which named the ostium maxillares at the level of the middle nasal maxillares at the level of the middle nasal meatus.meatus.

Osteum maxillares present in a recess Osteum maxillares present in a recess named hiatus semilunaresnamed hiatus semilunares

In some individuals 2 or many more In some individuals 2 or many more accessory ostia connect the middle nasal accessory ostia connect the middle nasal meatus (in 23% of cases). The accessory meatus (in 23% of cases). The accessory ostia occur rarely in the inferior meatus.ostia occur rarely in the inferior meatus.

During development the sinus During development the sinus pneumatizes the maxilla beyond the pneumatizes the maxilla beyond the boundry of the maxillary body. These boundry of the maxillary body. These expansions are found in the :expansions are found in the :

1. Alveolar process .1. Alveolar process . 2. Zygomatic process .2. Zygomatic process . 3. Frontal process .3. Frontal process . 4. Maxillary tuberosity .4. Maxillary tuberosity . 5. Palatine process of the maxilla .5. Palatine process of the maxilla .

The extension of sinus floor into the The extension of sinus floor into the alveolar process may make this floor to be alveolar process may make this floor to be found between the root of adjacent teeth found between the root of adjacent teeth as well as the roots of all individual tooth.as well as the roots of all individual tooth.

The apices may become protruded into The apices may become protruded into the sinus cavity and are covered by a the sinus cavity and are covered by a combination of the PDL and mucous combination of the PDL and mucous membrane that lines the sinus.membrane that lines the sinus.

Zygomatic expantion brings the Zygomatic expantion brings the superior alveolar neurovascular superior alveolar neurovascular bundles bundles into proximity with the into proximity with the space of the sinus .space of the sinus .

The teeth which are commonly The teeth which are commonly related to the sinus are related to the sinus are most most often often the the max. molar rootsmax. molar roots, , less less frequently frequently the the premolarspremolars and and rarelyrarely the the canine roots canine roots ..

Note:In the deciduous teeth the related teeth are the max.first and second molars – rarely the canine.

Relationship of the floor of the sinus to the roots of Relationship of the floor of the sinus to the roots of the maxillary teeththe maxillary teeth

Enlargement of the sinus toward Enlargement of the sinus toward the alveolar process may place the alveolar process may place the floor of the sinus in a position the floor of the sinus in a position ::

lower than that of the floor of the lower than that of the floor of the nasal cavity .nasal cavity .

Maxillary SinusMaxillary SinusBilateral pneumatic air space inside the body of the maxilla

that communicates with the nasal cavity(ostium) Four-sided pyramidBase: lateral wall of nasal cavityApex: towards zygomatic process

Anterior wall: facial surface of maxilla Posterio wall:infratemporal surface of the body of maxillaSuperior wall: floor of the orbitInferior wall:Towards alveolar and zygomatic process

Development 3 MIU Middle nasal meatus

(slit-like space)

Size

Newborn8 x 4 x 6 mm growth by

pneumatization

Adult2.3 x3.4 x3.3 cm

1. 1. Agenesis Agenesis : complete absence.: complete absence.

2.2. AplasiaAplasia and and hypoplasiahypoplasia : altered development or : altered development or underdevelopment of the sinus which occurs either underdevelopment of the sinus which occurs either alone or in association with other anomalies such as:alone or in association with other anomalies such as:

- Cleft palate.- Cleft palate. - High palate.- High palate. - Septal deformity.- Septal deformity. - Absence of a concha.- Absence of a concha. - Mandibulofacial dysostosis.- Mandibulofacial dysostosis. -Malformation of the exrernal nose.-Malformation of the exrernal nose.

3.3. Supernumerary sinusSupernumerary sinus may occur may occur on the same side by outpocketing on the same side by outpocketing of the nasal mucosa into the of the nasal mucosa into the primordium of the maxillary body primordium of the maxillary body from two points either in the from two points either in the middle nasal meatus or in the middle nasal meatus or in the middle and superior or middle and middle and superior or middle and inferior meatuses, respectively. inferior meatuses, respectively. The result is 2 permanently The result is 2 permanently separated ostia of the sinus.separated ostia of the sinus.

The maxillary sinus is lined by a The maxillary sinus is lined by a thin delicate mucous thin delicate mucous membrane .membrane .

Pseudostratified ,columnar ,ciliated Pseudostratified ,columnar ,ciliated type with goblet cells (secrets type with goblet cells (secrets mucus substances).mucus substances).

Derived from the olfactory Derived from the olfactory epithelium of the middle nasal epithelium of the middle nasal meatus.meatus.

The epithelial layer

The basal lamina

Lamina lucidaLamina lucida

Lamina densaLamina densa

Containing subepithelial mixed glands or a Containing subepithelial mixed glands or a pure population of cells of either secretory pure population of cells of either secretory type.type.

Secretion reaches the epithelial surface and Secretion reaches the epithelial surface and sinus lumen by way of excretory duct after sinus lumen by way of excretory duct after piercing the basal lamina. The myoepithelial piercing the basal lamina. The myoepithelial cells surround the acini.cells surround the acini.

Consists of loose bundles of Consists of loose bundles of collagenous fibers withcollagenous fibers withfew elastic fibers (moderatly few elastic fibers (moderatly vascular).vascular).

The subepithelial layer (The lamina propria) including the periostium

Goblet cells

Lamina propria

Epithelium

Mixed glands

Lining of maxillary sinus

Epithelium

Lamina Propria

1.1. Lightening of the skull weight.Lightening of the skull weight.2.2. Resonance of voice. Resonance of voice.3.3. Enhancement of faciocranial resistance to Enhancement of faciocranial resistance to

mechanical shock.mechanical shock.4.4. Humidification and warming of inspired air. Humidification and warming of inspired air.5.5. Protects the internal structures (brain) Protects the internal structures (brain)

against exposure to cold air.against exposure to cold air.6.6. Contribution to the olfaction. Contribution to the olfaction.7.7. Production of bactericidal lysozyme to the Production of bactericidal lysozyme to the

nasal cavity.nasal cavity.8.8. Cillia, withdraw out any foreign particles.Cillia, withdraw out any foreign particles.

1.1. In pitutary gaintism all sinuses In pitutary gaintism all sinuses assum a much large volume than in assum a much large volume than in healthy individuals .healthy individuals .

2.2. Congenital infections (by Congenital infections (by spirochetes in congenital syphilis) spirochetes in congenital syphilis) the pneumatic processes are greatly the pneumatic processes are greatly suppressed, resulting in small suppressed, resulting in small sinuses .sinuses .

3.3. Transfer of a pathologic condition Transfer of a pathologic condition from the sinus to from the sinus to the orodental apparatus , or the orodental apparatus , or vice versa by :vice versa by :

- Mechanical connection .- Mechanical connection . - Way of the blood or lymphatic - Way of the blood or lymphatic

pathways . pathways .

4.4. Surgical manipulation on upper 1 Surgical manipulation on upper 1stst molar may damage molar may damage the sinus (oroantral fistula) .the sinus (oroantral fistula) .

5.5. Extraction of hypercemetosed Extraction of hypercemetosed tooth may also lead to a tooth may also lead to a perforation (radiograph should be perforation (radiograph should be considered before extraction) .considered before extraction) .

6.6. Chronic infections of Chronic infections of mucoperiosteal layer of the mucoperiosteal layer of the sinus might involve superior sinus might involve superior alveolar nerves, and may alveolar nerves, and may neuralgia that mimics possible neuralgia that mimics possible dental origin .dental origin .

7.7. The neuralgia of the maxillary The neuralgia of the maxillary nerve could have an etiologic nerve could have an etiologic origin in the superior dental origin in the superior dental apparatus or the mucopriosteal apparatus or the mucopriosteal layer of the sinus or both . It is layer of the sinus or both . It is important to determine important to determine percisely the cause.percisely the cause.

8.8. Due to vascular connection between Due to vascular connection between the sinus and teeth by the superior the sinus and teeth by the superior alveolar vessels, bacterial sinusitis alveolar vessels, bacterial sinusitis may be followed by some oral may be followed by some oral manifestation .manifestation .

9.9. A fractured root may be forced A fractured root may be forced accidentally during surgical accidentally during surgical manipulation into the sinus if the manipulation into the sinus if the bone is thin .bone is thin .

10.10. Mlignant lesions of the sinus Mlignant lesions of the sinus may produce their primary may produce their primary manifestation in the maxillary manifestation in the maxillary teeth (pain, loosening, teeth (pain, loosening, supraeruption, or gingival supraeruption, or gingival bleeding) .bleeding) .

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