Ct anatomy of paranasal sinuses

CT ANATOMY OF PARANASAL SINUSES WITH LABALLED DIAGRAMS

1. MAAJID MOHI UD DIN MALIK LECTURER COPMS ADESH UNIVERSITY BATHINDA PUNJAB [email protected] CT ANATOMY OF PNS [email protected]

2. INTRODUCTION The paranasal sinuses are air cavities that help circulate the air that is breathed in and out of the respiratory system. They are situated around the nasal cavity  and they are all paired and sometimes symmetrical, while always being bilateral. [email protected]

3. CONTINUE There are four different pairs of sinuses and they are called the: Maxillary sinuses Frontal sinuses Sphenoidal sinuses Ethmoidal sinuses [email protected]

4. MAXILLARY SINUSES Superior wall  - bony orbit Inferior wall  - alveolar bone of the maxilla Medial wall  - nasal cavity Lateral and anterior walls  - cheekbones Posterior wall  - pterygopalatine fossa, infratemporal fossa Innervation  - anterior superior alveolar, middle superior, posterior superior nerves (branches of the maxillary nerve) Vascularization  - anterior superior alveolar, middle superior alveolar, posterior superior alveolar arteries (branches of the maxillary artery) [email protected]

5. FRONTAL SINUSES Anterior wall  - forehead and superciliary arches Superior and posterior walls  - anterior cranial fossa Inferior wall  - bony orbit Medial wall  - contralateral sinus Innervation  - supraorbital nerve, supratrochlear nerve (branches of the ophthalmic nerve) Vascularization  - anterior ethmoidal, supraorbital, supratrocheal arteries (branches of the ophthalmic artery) [email protected]

6. SPHENOIDAL SINUSES Anterior wall  - nasal cavity Superior wall  - hypophyseal fossa Inferior wall  - nasopharynx and pterygoid canal Innervation  - posterior ethmoidal nerve (branch of the nasociliary nerve) Vascularization  - posterior ethmoidal, posterior lateral nasal arteries (branches of the ophthalmic artery) [email protected]

7. ETHMOIDAL SINUSES Superior wall  - anterior cranial fossa, frontal bone Lateral wall  - bony orbit Medial wall  - nasal cavity Innervation  - anterior and posterior ethmoidal nerves (branches of the nasociliary nerve) Vascularization  - anterior and posterior ethmoidal arteries (branches of the ophthalmic artery) [email protected]

8. THE MAXILLARY SINUSES The maxillary sinuses are the largest of the all the paranasal sinuses. They have thin walls which are often penetrated by the long roots of the posterior maxillary teeth. The superior border of this sinus is the bony orbit, the inferior is the maxillary alveolar bone and corresponding tooth roots, the medial border is made up of the nasal cavity and the lateral and anterior border are limited by the cheekbones. Posteriorly, two anatomical spaces known as the pterygopalatine fossa and the infratemporal fossa exist. [email protected]

9. VASCULARIZATION, INNERVATION AND LYMPHATICS The submandibular lymph nodes are the main destination during lymphatic drainage. The blood supply includes a contribution from the:  Anterior superior alveolar artery Middle superior artery Posterior superior alveolar artery Innervation occurs through nerves of the same names as the arteries. [email protected]

10. THE FRONTAL SINUSES Anteriorly, the frontal sinuses are contained by the forehead and the superciliary arches, superiorly and posteriorly by the anterior cranial fossa and inferiorly by the bony orbit, the anterior ethmoidal sinuses and the nasal cavity. Medially the sinuses face one another, separated by the midline. This pair of sinuses are irregular in shape when compared to one another and is underdeveloped at birth. They reach their full size and shape around seven to eight years of age. [email protected]

11. VASCULARIZATION, INNERVATION AND LYMPHATICS They drain primarily into the ethmoidal infundibulum and the corresponding lymph drainage occurs via the submandibular lymph nodes. It is innervated by the ophthalmic nerve, including the supraorbital and supratrochlear branches. The frontal sinuses are supplied by the:  Anterior ethmoidal artery Supraorbital artery Supratrochlear artery [email protected]

12. THE SPHENOIDAL SINUSES The most posterior of all the sinuses in the head, the sphenoidal sinuses are large and irregular, just like their septum, which is made by the sphenoid bone. Laterally, a cavernous sinus exists which is part of the middle cranial fossa and also the carotid artery and cranial nerves III, IV, V/I, V/II and VI can be found. The anterior wall separates this pair of sinuses from the nasal cavity, as does the hypophyseal fossa, the pituitary gland and the optic chiasm superiorly and the nasopharynx and pterygoid canal inferiorly. [email protected]

13. VASCULARIZATION, INNERVATION AND LYMPHATICS The lymphatic drainage occurs in the same way as the posterior ethmoid sinus. The  posterior ethmoidal artery and the posterior lateral nasal branches supply the sphenoidal sinuses. The posterior ethmoidal nerve and the orbital branch of the pterygopalatine ganglion innervate them. [email protected]

14. THE ETHMOIDAL SINUSES Superior to the ethmoidal sinus is the anterior cranial fossa and the frontal bone, laterally the orbit can be found, while the nasal cavity is situated medially. The ethmoid sinuses are unique because they are the only paranasal sinuses that are more complex than just a single cavity. On each side of the midline, anywhere from three to eighteen ethmoidal air cells may be grouped together. These air cells are smaller individual sinuses grouped together to form one large one which encompass the anterior, middle and posterior nasal meatuses. [email protected]

15. VASCULARIZATION, INNERVATION AND LYMPHATICS The anterior and middle ethmoid sinuses send their lymphatic drainage to the submandibular lymph nodes while the posterior ethmoid sinus sends its own to the retropharyngeal lymph nodes. The anterior and posterior ethmoidal arteries, as well as the posterior lateral nasal branches provide an ample blood supply to this region. Meanwhile the anterior and posterior ethmoidal nerves and the posterior lateral superior and inferior nasal nerves help innervate it. [email protected]

16. PNS [email protected]

17. [email protected]

18. [email protected]

19. AXIAL SECTIONS OF CT PNS [email protected]

20. 1, ORBITAL CAVITY. 2, FRONTAL SINUS. 3, SPHENOID BONE [email protected]

21. 1, GLOBE. 2, NASAL SEPTUM. 3, ETHMOIDAL CELLS. 4, SPHENOIDAL SINUS. 5, PITUITARY GLAND. 6, DORSUM SELLAE [email protected]

22. 1, GLOBE. 2, NASAL SEPTUM. 3, ETHMOIDAL CELLS. 4, SPHENOIDAL SINUS. 5, CLIVUS [email protected]

23. 1, MAXILLARY SINUS (LEFT SIDE). 2, RIGHT NASOLACRIMAL DUCT. 3, TURBINATE. 4, NASAL SEPTUM. 5, ZYGOMATIC ARCH. 6, CONDYLAR PROCESS OF MANDIBLE [email protected]

24. 1, NASAL CONCHA. 2, MAXILLARY SINUS. 3, LATERAL LAMINA OF PTERYGOID PROCESS. 4, NASOPHARYNX. 5, ATLAS. 6, PTERYGOMAXILLARY FISSURE [email protected]

25. 1, MAXILLARY SINUS. 2, PTERYGOID PROCESS. 3, NASOPHARYNX. 4, MANDIBLE. 5, ANTERIOR ARCH OF C1 (ATLAS). 6, ODONTOID PROCESS (AXIS) [email protected]

26. CORONAL SECTIONS OF CT PNS [email protected]

27. 1, ANTERIOR CLINOID PROCESS. 2, SPHENOIDAL SINUS. 3, RHINOPHARYNX. 4, PTERYGOID HAMULUS. 5, ZYGOMATIC ARCH. 6, MANDIBLE [email protected]

28. 1, SPHENOIDAL SINUS. 2, MIDDLE NASAL CONCHA. 3, INFERIOR NASAL CONCHA. 4, ZYGOMATIC ARCH. 5, MANDIBLE [email protected]

29. 1, ORBITAL CAVITY. 2, ETHMOIDAL CELLS. 3, MIDDLE NASAL CONCHA. 4, INFERIOR NASAL CONCHA. 5, MAXILLARY SINUS (RIGHT SIDE). 6, ZYGOMATIC ARCH. 7, MANDIBLE [email protected]

30. 1, FRONTAL BONE. 2, SUPERIOR RECTUS MUSCLE. 3, OPTIC NERVE. 4, LATERAL RECTUS MUSCLE. 5, INFERIOR RECTUS MUSCLE. 6, MEDIAL RECTUS MUSCLE. 7, ZYGOMATIC ARCH. 8, MIDDLE NASAL CONCHA. 9, INFERIOR NASAL CONCHA. 10, HARD PALATE [email protected]

31. 1, CRISTA GALLI. 2, SUPERIOR OBLIQUE MUSCLE. 3, SUPERIOR RECTUS MUSCLE. 4, LATERAL RECTUS MUSCLE 5, INFERIOR RECTUS MUSCLE. 6, MEDIAL RECTUS MUSCLE. 7, OPTIC NERVE. 8, MIDDLE NASAL CONCHA. 9, INFERIOR NASAL CONCHA. 10, HARD PALATE [email protected]

32. 1, FRONTAL SINUS. 2, FRONTAL BONE. 3, GLOBE. 4, MAXILLARY SINUS. 5, NASAL SEPTUM. 6, INFERIOR NASAL CONCHA [email protected]

33. 1, FRONTAL SINUS. 2, NASAL BONE. 3, NASAL CAVITY. 4, ALVEOLAR ARCH [email protected]

34. SAGITTAL SECTIONS OF CT PNS [email protected]

35. 1, FRONTAL BONE. 2, ORBITAL CAVITY. 3, MAXILLARY SINUS [email protected]

36. 1, FRONTAL SINUS. 2, ORBITAL CAVITY. 3, OPTIC NERVE. 4, MAXILLARY SINUS. 5, INFERIOR ORBITAL FISSURE [email protected]

37. 1, FRONTAL SINUS. 2, MAXILLARY SINUS. 3, ALVEOLAR ARCH (MAXILLA) [email protected]

38. 1, NASAL BONE. 2, FRONTAL SINUS. 3, ETHMOIDAL CELLS. 4, SPHENOIDAL SINUS. 5, INFERIOR NASAL CONCHA. 6, HARD PALATE [email protected]

39. 1, FRONTAL SINUS. 2, HYPOPHYSEAL FOSSA. 3, SPHENOIDAL SINUS. 4, CLIVUS. 5, ODONTOID PROCESS (C2 - AXIS). 6, ANTERIOR ARCH OF C1 (ATLAS). 7, RHINOPHARYNX [email protected]

40. 1, FRONTAL SINUS. 2, ETHMOIDAL CELLS. 3, SPHENOIDAL SINUS. 4, CLIVUS. 5, MIDDLE NASAL CONCHA. 6, INFERIOR NASAL CONCHA. 7, HARD PALATE [email protected]

41. ANY QUESTION? [email protected]