Maxillary sinus

oral histology

1. Maxillary sinus Dr: mahmoud 3mmar Dr: 0106 39 700 30 f.B : [email protected]

2. 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 .

3. 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 .

4. 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 .

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

6. 3- histology of maxillary sinus:- walls of sinus are lined by thin mucos membrane ( epith . & C.T ) similar to respiratory type but thinne r , 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

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

8. 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

9. 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

10. 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.

11. 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.

12. 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

13. 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.

14. Hiatus Semilunaris

15. 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.

16. 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.

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

18. 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.

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

20. 4. Surgical manipulation on upper 1 st molar may damage the sinus ( oroantral fistula) . 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 .

21. 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) .

22. thanks