Clinical features of the anatomy of the nose and paranasal sinuses. Variants of the anatomy of the paranasal sinuses Components of the lateral wall of the nasal cavity

09.05.2020

upper nasal passage (meatus nasalis superior) is located between the superior turbinate above and the middle turbinate below. in this nasal passage, the posterior cells of the ethmoid bone open. behind the superior turbinate located wedge-shaped lattice depression (reccessus sphenoethmoidal), which opens sphenoid sinus opening (areg-tura sinus sphenoidalis). middle nasal passage (meatus nasalis medius) is located between the middle and lower turbinates. it is much longer, higher and wider than the top. in the middle nasal passage, the anterior and middle cells of the ethmoid bone open, the aperture of the frontal sinus through lattice funnel (infundibulum ethmoidale) and lunar cleft (hiatus semi-

fig. 90. the lateral wall of the nasal cavity and openings in it, leading to paranasal sinuses nose. view from the side of the nasal cavity. sagittal cut through the right half of the nasal cavity. the superior and middle turbinates are partially removed.

1 - orbital part of the frontal bone, 2 - ethmoid plate, 3 - superior nasal concha, 4 - openings of the posterior cells of the ethmoid bone, 5 - aperture of the sphenoid sinus, 6 - sphenoid sinus, 7 - pituitary fossa, 8 - upper nasal passage, 9 - wedge-palatine opening, 10 - middle turbinate, 11 - middle nasal passage, 12 - maxillary cleft, 13- lower nasal passage, 14 - hard palate, 15 - incisor canal, 16 - nasolacrimal canal outlet, 17 - lower nasal concha, 18 - ethmoid vesicle, 19 - hooked process, 20 - ethmoid funnel, 21 - nasal bone, 22 - openings of the anterior ethmoid cells, 23 - nasal spine of the frontal bone, 24 - frontal sinus, 25 - openings of the middle cells of the ethmoid bone ...

lunaris), leading to the maxillary sinus. located behind the middle turbinate wedge-palatine opening (foramen sphenopalatinum) connects the nasal cavity with the pterygo-palatine fossa. lower nasal passage (meatus nasalis inferior), the longest and widest, is bounded from above by the inferior nasal concha, and from below by the nasal surface of the palatine process of the maxillary bone and the horizontal plate of the palatine bone. in front section the lower nasal passage opens the nasolacrimal canal starting in the orbit.

the space in the form of a narrow sagittally located slit, bounded by the septum of the nasal cavity from the medial side and the turbinates from the lateral side, is common nasal passage (meatus nasalis communis).

The nasal cavity has paranasal sinuses, which communicate with various nasal passages (Fig. 50). So, in the upper nasal passage, the body cavity of the main bone and the posterior cells of the ethmoid bone open, in the middle nasal passage - the frontal and maxillary sinuses, the anterior and middle cells of the ethmoid bone. The lacrimal canal flows into the lower nasal passage.

Figure: fifty.
A - the outer wall of the nasal cavity with holes in the paranasal sinuses: 1 - the frontal sinus; 3 - opening of the frontal sinus; 3 - aperture of the anterior ethmoid cells; 4 - hole maxillary sinus; 5 - holes of the posterior cells of the ethmoid bone; 6 - the main sinus and its opening; 7 - pharyngeal opening auditory tube; 8 - opening of the nasolacrimal duct. B - nasal septum: 1 - crista galli; 2 - lamina cribrosa; 3 - lamina perpendicularis ossis ethmoidalis; 4 - opener; 5 - hard palate; 5 - cartilago septi nasi.

Maxillary sinus (sinus maxillaris Highmori) located in the body upper jaw... It begins to be created from the 10th week of embryonic life and develops up to 12-13 years. In an adult, the volume of the cavity ranges from 4.2-30 cm 3, it depends on the thickness of its walls and, less, on its position. The shape of the sinus is irregular, it has four main walls. The anterior (in 1/3 of cases) or antero-external (in 2/3 of cases) wall is represented by a thin plate corresponding to the fossa canina. There is n on this wall. infraorbitalis together with the blood vessels of the same name.

The upper wall of the sinus is also the lower wall of the orbit. In the thickness of the wall there is canalis infraorbitalis, containing the mentioned neurovascular bundle. At the site of the latter, the bone may be thinned or have a gap. In the presence of a gap, the nerve and blood vessels are separated from the sinus only by the mucous membrane, which leads to inflammation of the inferior orbital nerve with sinusitis. Usually, the top wall of the sinus is flush with top middle nasal passage. N.N. Rezanov points to a rare variant when this wall of the sinus is low and the middle nasal passage is adjacent to the inner surface of the orbit. This is due to the possibility of penetration into the orbit of the needle during puncture maxillary sinus through the nasal cavity. Often, the dome of the sinus extends into the thickness of the inner wall of the orbit, pushes the ethmoid sinuses up and back.

Bottom wall the maxillary sinus is represented by the alveolar process of the jaw, corresponding to the roots of the 2nd small and anterior large molars. The zone of the position of the roots of the teeth can protrude into the cavity in the form of an elevation. The bone plate separating the cavity from the root is often thinned, sometimes has a gap. These conditions favor the spread of infection from the affected roots of the teeth to the maxillary sinus, explain the cases of penetration of the tooth into the sinus at the time of its extirpation. The bottom of the sinus can be 1–2 mm above the bottom of the nasal cavity, at the level of this bottom or below it as a result of the development of the alveolar bay. The maxillary cavity rarely extends under the bottom of the nasal cavity, forming a small depression (buchta palatina) (Fig. 51).

Figure: 51. Paranasal sinuses, maxillary sinus.
A - sagittal cut: B - frontal cut; В - construction options - high and low position of the lower wall: 1 - canalis infraorbitalis; 2 - fissura orbitalis Inferior; 3 - fossa pterygopalatina; 4 - maxillary sinus; 5- ethmoid cells; 6 - eye socket; 7 - processus alveolaris; 8 - lower nasal concha; 9 - nasal cavity; 10 - buchta prelacrimalis; 11 - canalis infraorbitalis (deprived of the lower wall); 12 - buchta palatina; 13 - buchta alveolaris; G - frontal sinus on a sagittal cut; D - options for the structure of the frontal sinus.

The inner wall of the maxillary sinus is adjacent to the middle and lower nasal passages. The wall of the lower nasal passage is solid, but thin. Here it is relatively easy to puncture the maxillary sinus. The wall of the middle nasal passage has a webbed structure and an opening communicating the sinus with the nasal cavity over a considerable extent. Hole length 3-19 mm, width 3-6 mm.

The posterior wall of the maxillary sinus is represented by the maxillary tubercle in contact with the pterygopalatine fossa, where n. infraorbitalis, ganglion sphenopalatinum, a. maxillaris with its branches. Through this wall you can approach the pterygopalatine fossa.

Frontal sinuses (sinus frontalis) are located in the thickness of the frontal bone, corresponding to the superciliary arches. They look like triangular pyramids with a downward base. Sinuses develop from 5-6 to 18-20 years. In adults, their volume reaches 8 cm 3. Upward, the sinus extends somewhat beyond the superciliary arches, outward - to the outer third of the upper edge of the orbit or to the supraorbital notch and descends down into the nasal part of the bone. The anterior wall of the sinus is represented by the superciliary tubercle, the posterior wall is relatively thin and separates the sinus from the anterior cranial fossa, the lower wall forms part of the upper wall of the orbit and at the midline of the body - part of the nasal cavity, the inner wall is the septum separating the right and left sinuses. The top and side walls are absent, since its front and back walls converge at an acute angle. The cavity is absent in about 7% of cases. The partition separating the cavities from each other does not occupy a middle position in 51.2% (M.V. Miloslavsky). The cavity is opened through a canal (canalis nasofrontalis) up to 5 mm in length into the middle nasal passage, in front of the opening of the maxillary sinus. In the frontal sinus, canalis nasofrontalis forms at the bottom of its funnel. This promotes the drainage of mucus from the sinus. Tillo points out that the frontal sinus can sometimes open into the maxillary sinus.

Ethmoid sinuses (sinus ethmoidalis) are represented by cells corresponding to the level of the upper and middle turbinates, constituting the upper part of the lateral wall of the nasal cavity. These cells communicate with each other. On the outside, the cavities are delimited from the orbit by a very thin bone plate (lamina papyrocea). If this wall is damaged, air from the cells of the cavity can penetrate into the tissue of the periorbital space. The resulting emphysema produces a protrusion eyeball - exophthalmos. From above, the cells of the sinus are delimited by a thin bony septum from the anterior cranial fossa. The anterior group of cells opens into the middle nasal passage, the posterior one - into the upper nasal passage.

Main sinus (sinus sphenoidalis) is located in the body of the main bone. It develops between the ages of 2 and 20. The sinus is divided into right and left by a septum along the midline. The sinus opens into the upper nasal passage. The hole lies 7 cm from the nostril along a line following through the middle of the middle turbinate. The position of the sinus made it possible to recommend that surgeons approach the pituitary gland through the nasal cavity and nasopharynx. The main sinus may be absent.

Lacrimal canal (canalis nasolacrimalis) is located in the zone of the lateral border of the nasal region (Fig. 52). It opens into the lower nasal passage. The canal opening is located under the anterior edge of the inferior turbinate on the outer wall of the nasal passage. It is 2.5-4 cm from the posterior edge of the nostril. The length of the lacrimal canal is 2.25-3.25 cm (N.I. Pirogov). The channel runs in the thickness of the outer wall of the nasal cavity. In the lower segment, it is limited bone tissue only from the outside, from other sides it is covered with the mucous membrane of the nasal cavity.

Figure: 52. Topography of the lacrimal passages.
1 - fornix sacci lacrimalis; 2 - ductus lacrimalis superior; 3 - papilla et punctum lacrimale superior; 5 - caruncula lacrimalis; 6 - ductus et ampula lacrimalis Inferior; 7 - saccus lacrimalis; 8 - m. orbicularis oculi; 9 - m. obliquus oculi inferior; 10 - sinus maxillaris; 11 - ductus nasolacrimalis.
A - cross section: 1 - lig. palpebrale medialis; 2 - pars lacrimalis m. orbicularis oculi; 3 - septum orbitale; 4 - f. lacrimalis; 5 - saccus lacrimalis; 6 - periosteum

Initial upper division respiratory tract - consists of three parts.

Three components of the nose

external nose
nasal cavity
paranasal sinuses, which communicate with the nasal cavity through narrow openings

Appearance and external structure of the external nose

External nose

External nose is a bone-cartilaginous formation covered with muscles and skin, in appearance resembling a hollow triangular pyramid of irregular shape.

Nasal bones - This is the paired base of the external nose. Attached to the nasal part of the frontal bone, they, joining each other in the middle, form the back of the outer nose in its upper part.

Cartilage of the nose, being a continuation of the bone skeleton, is tightly welded to the latter and forms the wings and tip of the nose.

The wing of the nose, in addition to the larger cartilage, includes connective tissue formations, from which the posterior parts of the nasal openings are formed. Internal departments the nostrils are formed by the movable part of the nasal septum - columella.

Musculoskeletal... The skin of the outer nose has many sebaceous glands (mainly in the lower third of the outer nose); a large number of hairs (on the eve of the nose) that perform a protective function; as well as an abundance of capillaries and nerve fibers (this explains the pain of nose injuries). The muscles of the external nose are designed to compress the nasal openings and pull the wings of the nose downward.

Nasal cavity

The entrance "gate" of the respiratory tract, through which the inhaled (and also exhaled) air passes, is the nasal cavity - the space between the anterior cranial fossa and the oral cavity.

The nasal cavity, divided by the osteochondral nasal septum into the right and left halves and communicating with the external environment through the nostrils, also has posterior openings - choanae leading to the nasopharynx.

Each half of the nose has four walls. The bottom wall (bottom) is the bones hard palate; the upper wall is a thin bone, sieve-like plate through which branches of the olfactory nerve and vessels pass; the inner wall is the nasal septum; the side wall formed by several bones has the so-called turbinates.

The turbinates (lower, middle, and upper) divide the right and left halves of the nasal cavity into sinuous nasal passages - upper, middle, and lower. In the upper and middle nasal passages there are small openings through which the nasal cavity communicates with the paranasal sinuses. In the lower nasal passage there is an opening of the nasolacrimal canal, through which tears flow into the nasal cavity.

Three areas of the nasal cavity

the threshold
respiratory area
olfactory area

Major bones and cartilage of the nose

Very often, the nasal septum is twisted (especially in men). This leads to shortness of breath and, as a consequence, surgery.

The vestibule bounded by the wings of the nose, its edge is lined with a 4-5 mm strip of skin, equipped with a large number of hairs.

Respiratory area - This is the space from the bottom of the nasal cavity to the lower edge of the middle turbinate, lined with a mucous membrane formed by many goblet cells that secrete mucus.

A common man's nose can distinguish about ten thousand odors, and a taster's - much more.

The superficial layer of the mucous membrane (epithelium) has special cilia with a flickering movement directed towards the choanas. Under the mucous membrane of the nasal concha lies a tissue consisting of a plexus of blood vessels, which promotes instant swelling of the mucous membrane and narrowing of the nasal passages under the influence of physical, chemical and psychogenic stimuli.

Antiseptic nasal mucus destroys a large number of microbes trying to enter the body. If there are a lot of microbes, the volume of mucus also increases, which leads to a runny nose.

A runny nose is the most common disease in the world, which is why it is even included in the Guinness Book of Records. On average, an adult has a runny nose up to ten times a year, and spends his entire life with a stuffy nose for up to three years in total.

Olfactory area (olfactory organ), painted in yellowish-brown color, occupies part of the upper nasal passage and the posterior-superior part of the septum; its border is the lower edge of the middle turbinate. This zone is lined with epithelium containing olfactory receptor cells.

The olfactory cells are spindle-shaped and end on the surface of the mucous membrane with olfactory vesicles supplied with cilia. The opposite end of each olfactory cell continues into nerve fiber... Such fibers, connecting in bundles, form the olfactory nerves (I pair). Odorous substances, getting into the nose together with the air, reach the olfactory receptors by diffusion through the mucus that covers the sensitive cells, chemically interact with them and cause excitement in them. This excitement travels along the fibers of the olfactory nerve to the brain, where odors are distinguished.

During a meal, the olfactory sensation complements the gustatory sensation. With a runny nose, the sense of smell is dulled, and the food seems tasteless. With the help of the sense of smell, the smell of unwanted impurities in the atmosphere is caught; by smell, it is sometimes possible to distinguish poor-quality food from suitable for eating.

The olfactory receptors are very sensitive to odors. To excite the receptor, it is enough that only a few molecules of the odorous substance act on it.

The structure of the nasal cavity

Our smaller brothers - animals - are more than human, not indifferent to smells.
Birds, fish, and insects all smell from a great distance. Petrels, albatrosses, fulmars can smell fish at a distance of 3 km or more. It has been confirmed that pigeons find their way by smells, flying many kilometers.
For moles, the supersensitive sense of smell is a sure guide to the underground labyrinths.
Sharks smell blood in the water even at a concentration of 1: 100,000,000.
It is believed that the most acute sense of smell is in the male common moth.
Butterflies almost never sit on the first flower they come across: they sniff, circle over the flower bed. Very rarely, butterflies are attracted by poisonous flowers. If this happens, the "victim" sits down by the puddle and drinks heavily.

Paranasal (paranasal) sinuses

Paranasal sinuses (sinusitis) - these are air cavities (paired) located in the face of the skull around the nose and communicating with its cavity through the outflow openings (fistulas).

Maxillary sinus - the largest (the volume of each of the sinuses is about 30 cm 3) - located between the lower edge of the orbit and the dentition of the upper jaw.

On the inner wall of the sinus, bordering the nasal cavity, there is an anastomosis leading to the middle nasal passage of the nasal cavity. Since the opening is located almost under the "roof" of the sinus, it hinders the outflow of the contents and contributes to the development of stagnant inflammatory processes.

The anterior, or front, wall of the sinus has a depression called a canine fossa. In this area, the sinus is usually opened during surgery.

The upper wall of the sinus is also the lower wall of the orbit. The bottom of the maxillary sinus is very close to the roots of the posterior upper teethto the point that sometimes the sinus and teeth are separated only by the mucous membrane, and this can lead to infection of the sinus.

The maxillary sinus got its name from the name of the English doctor Nathaniel Highmore, who first described her diseases

Layout of the paranasal sinuses

The thick posterior wall of the sinus is bordered by the cells of the ethmoid labyrinth and the sphenoid sinus.

Frontal sinus is located in the thickness of the frontal bone and has four walls. With the help of a thin tortuous canal that opens into the anterior part of the middle nasal passage, the frontal sinus communicates with the nasal cavity. The inferior wall of the frontal sinus is the superior wall of the orbit. The median wall separates the left frontal sinus from the right, the posterior wall is the frontal sinus from the frontal lobe of the brain.

Ethmoid sinus, also called "labyrinth", is located between the orbit and the nasal cavity and consists of separate airway bony cells. There are three groups of cells: anterior and middle, opening in the middle nasal passage, and posterior, opening in the upper nasal passage.

Sphenoid (main) sinus lies deep in the body of the sphenoid (main) bone of the skull, divided by a septum into two separate halves, each of which has an independent exit to the area of \u200b\u200bthe upper nasal passage.

At birth, a person has only two sinuses: the maxillary and ethmoid labyrinth. Frontal and sphenoid sinuses in newborns are absent and begin to form only from 3-4 years old. The final development of the sinuses is completed by about 25 years of age.

Functions of the nose and paranasal sinuses

The complex structure of the nose ensures that it successfully fulfills the four functions assigned to it by nature.

Olfactory function... The nose is one of essential organs feelings. With its help, a person perceives all the variety of smells around him. Loss of smell not only impoverishes the palette of sensations, but is also fraught with negative consequences. After all, some smells (for example, the smell of gas or spoiled food) signal a danger.

Respiratory function - most important. It provides oxygen to the tissues of the body, which is necessary for normal life and blood gas exchange. With difficulty in nasal breathing, the course of oxidative processes in the body changes, which leads to disruption of the cardiovascular and nervous systems, disorders of the functions of the lower respiratory tract and gastrointestinal tract, increased intracranial pressure.

An important role is played by the aesthetic value of the nose. Often, providing normal nasal breathing and the sense of smell, the shape of the nose gives its owner significant experiences, not corresponding to his ideas of beauty. In this regard, one has to resort to plastic surgerycorrecting appearance external nose.

Protective function... Inhaled air, passing through the nasal cavity, is cleared of dust particles. Large dust particles are trapped by hairs that grow at the entrance to the nose; part of the dust particles and bacteria, passing with the air in the winding nasal passages, settles on the mucous membrane. Non-stop vibrations of the cilia of the ciliated epithelium remove mucus from the nasal cavity into the nasopharynx, from where it is coughed up or swallowed. Bacteria that enter the nasal cavity are largely neutralized by substances contained in the nasal mucus. Cold air, passing through narrow and winding nasal passages, is warmed and moistened by the mucous membrane, which is abundantly supplied with blood.

Resonator function. Nasal cavity and the paranasal sinuses can be compared to an acoustic system: the sound, reaching their walls, is amplified. The nose and sinuses play a leading role in the pronunciation of nasal consonants. Nasal congestion causes nasal sounds, in which nasal sounds are not pronounced correctly.

Translation into Russian of the article "Illustrated Essay: Anatomical Variations of the Paranasal Sinuses in computed tomography... How does this help surgeons with endoscopic surgery? "

The lateral wall of the nasal cavity contains protrusions, which are called the upper, middle and lower turbinates, they divide the nasal cavity into the upper, middle and lower nasal passages. The upper nasal passage is drained into the posterior ethmoidal cells, and the wedge-shaped sinuses are drained into it through the sphenoetmoidal pocket. The frontal sinuses are drained into the middle nasal passage through the frontal pockets and maxillary sinuses through the openings of the sinuses, as well as the anterior ethmoid cells through their openings. The nasolacrimal canal is drained into the lower nasal passage.

Ostiomeatal complex

Ostiomeatal complex (hereinafter referred to as OMC) includes the opening of the maxillary sinus, ethmoid funnel, anterior ethmoid cells and frontal pocket (Fig. 1A). These structures are called anterior sinuses. OMK is a key structure in the pathogenesis of chronic sinusitis. Ethmoid cells are key to the drainage of the anterior sinuses. They are susceptible to injury during surgery due to their close connection with the orbit and anterior skull base.

Nasal tubercle cell

Nasal tubercle cell - the most anterior ethmoid cell, which protrudes anteriorly into the lacrimal bone. It is located in front, lower in relation to the frontal pocket, and is bordered by the opening of the frontal sinus (Fig. 1B). A good examination of the frontal pocket is possible when the nasal tubercle cell is opened. Its size can directly affect the patency of the frontal pocket and the anterior parts of the middle nasal passage.

Frontal pocket

Frontal pocket is a narrow air-containing channel that communicates with the frontal sinus. The frontal pocket is a frequent site for all sorts of inflammatory processes. The walls of the canal are formed by the cells of the tubercle of the nose in front, the paper plate laterally, the middle nasal concha medially (Fig. 1B). The pocket opens 62% into the middle nasal passage, 38% into the lattice funnel. On coronal scans, the pocket is defined above the nasal tubercle cell.

Lattice funnel

Lattice funnel bounded in front by the hook-shaped process, behind by the front wall of the ethmoid bulla, and by the lateral paper plate (Fig. 1A). It opens into the middle nasal passage medially through the lunate fissure. On coronal scans, the bulla is located above the lattice funnel. The mouth of the maxillary sinus opens at the bottom of the funnel.

The ethmoid fossa is a critical element of anatomy for two reasons. First, it is most sensitive to iatrogenic damage and, as a consequence, the formation of CSF fistulas. Second, the anterior ethmoid artery is at risk of injury, which can lead to uncontrolled bleeding into the orbit. In endoscopic surgery, intracranial injury can occur on the side where the ethmoid fossa is located below (Fig. 2).

The depth of the olfactory pit is determined by the height of the lateral lamella of the sieve plate, which is part of the ethmoid bone. In 1962 Keros classified the depth of the olfactory pit into three types: Keros 1, when the pit is less than 3 mm deep (Fig. 3), Keros 2, when the pit is 4-7 mm deep (Fig. 4), Keros 3, when the pit is 8 -16 mm deep (Fig. 5). Keros type 3 is the most dangerous for iatrogenic damage.

Onodi cells

Onodi cells are posterior ethmoidal cells that protrude into the wedge-shaped sinuses (Fig. 6) and can even reach optic nerve... When Onodi cells adjoin or surround the optic nerve, the nerve is at risk when surgical removal these cells. This results in incomplete sphenoidectomy.

According to radiopedia.org, Onodi cells are sphenoetmoidal air cells, which are also defined as the most posterior ethmoidal cells that protrude posteriorly, upward and lateral to the sphenoid sinuses, located in close proximity to the optic nerve and the internal carotid artery. They often extend to the anterior oblique processes; it is important that the airiness of the anterior inclined process may be due simply to such a variant of the anatomy of the wedge-shaped sinus and does not necessarily indicate the presence of an Onodi cell.

Sphenoid sinus septum is attached to the wall containing the protrusion of the internal carotid artery, so arterial damage may be caused by removal of this sinus septum (Fig. 7). The artery can prolapse into the sinus in 65-72% of cases. There may be dehiscence or absence of the bone wall between the artery and the sinus in 4-8% of cases.

Sinus agenesis can also be seen (Fig. 8).

The pterygoid canal (Fig. 9) or the maxillary nerve groove (Fig. 10) can prolapse into the sphenoid sinus, which contributes to neuralgia. trigeminal nervecaused by sinusitis.

Pneumatization of the anterior tilted processes (Fig. 9) is associated with type 2 and type 3 optic nerve positions and predisposes to nerve damage during endoscopic surgery.

Variants of the relationship between the optic nerve and the posterior paranasal sinuses

Optic nerve carotid arteries and the Vidian canal are formed before the appearance of the paranasal sinuses and contribute to congenital variants of the structure of the walls of the wedge-shaped sinuses. Delano, et al. divide the relationship between the optic nerve and the posterior paranasal sinuses into 4 groups:

Type 1: Most common type, found in 76% of cases. In this case, the optic nerves are adjacent to the sphenoid sinus without the formation of depressions in its walls or contact with the posterior ethmoid cells (Fig. 11).
Type 2: The optic nerves are adjacent to the wedge-shaped sinus, and the walls of the sinus deepen without contact with the posterior ethmoid cells (Fig. 12).
Type 3: The nerves pass through the wedge-shaped sinuses, with at least half of the nerve circumference being surrounded by air (Fig. 13)
Type 4: nerves adjacent to the wedge-shaped sinus and posterior ethmoidal cells (Figs. 14 and 15).

Delano, et al. found that in 85% of cases pneumatized anterior tilted processes were associated with type 2 or 3 optic nerve position, while 77% showed dehiscence of the nerve canal wall (Fig. 16), which is associated with an increased risk of optic nerve injury with endoscopic surgery.

The sphenoid sinus septa can attach to the optic nerve canal wall, predisposing to nerve trauma during surgery (Fig. 17).

Middle turbinate options

The normal curvature of the middle turbinate is medial. When the bend is lateral, this is referred to as the paradoxical bend of the middle turbinate (Fig. 18). Most authors agree that a paradoxically curved middle turbinate may be a contributing factor to sinusitis.

Сoncha bullosa is an aerated concha, usually the middle turbinate. When pneumatization involves the bulb of the middle turbinate, this condition is called concha bullosa (Fig. 19). If pneumatization involves the attachment of the middle turbinate to the base of the skull, this condition is called lamellar concha (Fig. 20).

Hook-shaped process options

On coronal scans, it can be determined that the posterior section of the uncinate process is attached to the inferior turbinate at the bottom, while the posterior edge of the process remains free. The anterior section of the uncinate process is attached to the base of the skull from above, to the middle turbinate medially, to the paper plate or to the cusp of the nasal tubercle laterally.

The uncinate process can be medialized, lateralized, pneumatized, or curved. Medialization occurs as a large ethmoid bulla is present. Lateralization occurs when trellised funnel obstruction occurs. Pneumatization of the uncinate process (processus bulla) (Fig. 21) occurs in 4% of the population and rarely leads to obstruction of the ethmoid funnel.

Haller's cells

Haller's cells, they are infraorbial ethmoid cells (Fig. 22), located along the medial wall of the maxillary sinus and the lowest portion of the paper plate, below the ethmoid bulla, lateral to the uncinate process. These cells can narrow the ethmoid funnel and the mouth of the maxillary sinus, contribute to the appearance of recurrent maxillary sinusitis.

According to radiopedia.org, Haller's cells (infraorbital ethmoidal cells or maxilloethmoid cells) are extramural ethmoidal cells that project towards the inferior medial orbital edge and are present in about 20% of patients (2-45%). Their importance increases when they are affected by the inflammatory process, inflammation from them can move into orbit; cells can narrow the ethmoid funnel or the mouth of the maxillary sinus, if the cells are large, and contribute to sinus obstruction during inflammation; when resecting a Haller's cell, the orbit may be damaged.

Lattice bull

The largest and most prominent front trellis cage is called lattice bull... It is located lateral to the paper plate. The bulla can merge with the base of the skull from above and the basal plate of the middle turbinate behind. On coronal scans, it is located upward from the lattice funnel (Fig. 23). The decrease in the degree of pneumatization of the bulla varies, and the absence of pneumatization of the bulla is called torus ethmoidalis. The giant bulla can fill the middle nasal passage and is located between the uncinate process and the middle turbinate.

Air cells of the posterior-superior portion of the nasal septum

Air cells can be located in the back-upper portion of the nasal septum and connect with the wedge-shaped sinus (Fig. 24). Inflammatory processes, which are found in the paranasal sinuses, can also affect these cells. These cells can resemble a cephalocele.

Cockscomb

Cockscomb can be pneumatized, while the ridge can communicate with the frontal pocket, cause obstruction of the frontal sinus opening and lead to chronic sinusitis or mucocele formation. It is important to detect and distinguish this ethmoid cell variant before surgery to avoid penetration into the anterior cranial fossa.

In the outer nose distinguish between the nose bridge, passing into the back of the nose, formed by the convergence of its lateral surfaces (lateral slopes). The bridge of the nose ends with the tip of the nose. The lower part of the lateral surfaces is formed by the wings of the nose, which are separated from the lateral surface of the pterygoid, and from the upper lip-nasolabial groove. The nasal openings, nostrils (nares), are separated by the movable part of the nasal septum.

Bone skeleton of the external nose consists of the nasal bones and the frontal processes of the upper jaw. The upper ends of the nasal bones at the junction with the nasal processes of the frontal bone form the root of the nose (nose bridge). The lateral edges of the nasal bones are connected along the entire length with the frontal processes of the upper jaw, forming the lateral surface of the nose, while the inner edges are connected to each other, and below with triangular cartilage; the frontal processes of the upper jaw are connected at the top through a suture with the frontal bone, medial with the nasal bones, and laterally form part of the inner and lower edges of the orbit.

Nasal bones, the frontal processes of the upper jaw and the anterior lower nasal spine of the upper jaw limit the pear-shaped opening on the macerated skull, which is naturally closed by the cartilaginous framework of the nose. The latter consists of unpaired quadrangular cartilage adjacent to the antero-lower edge of the bony nasal septum, and paired lateral (triangular) and large and small wing cartilages. There are many sebaceous glands at the end of the outer nose. Curving over the edge of the nasal openings, the skin extends to the vestibule of the nasal cavity, where it is supplied with hairs.

Vessels of the external nose represented by the branches of the external jaw artery and the orbital artery, anastomosing with each other. All arteries are directed to the coccyx of the nose, which is rich in blood supply. The veins of the external nose anastomose with the veins of the nasal cavity and flow into the anterior facial vein. Insertion of the muscles of the external nose is carried out by branches facial nerve, and the skin is its first and second branches of the trigeminal nerve.

Lateral nasal wall the most complex in its structure. It is formed (going from front to back) by the inner surface of the nasal bone, the inner surface of the frontal process, to which the lacrimal bone adjoins above and behind, and the medial (nasal) surface of the upper jaw body, on which there is a large round or oval opening (hiatus maxillaris) leading into the maxillary sinus.

Further into the composition of the wall the vertical plate of the palatine bone enters, limiting the posterior inferior edge of the sinus opening, and, finally, the lateral wall is closed behind the medial plate of the main bone. Between the processes of the upper end of the vertical plate of the palatine bone and the body of the main bone there is an opening - foramen sphenopalatinum, connecting the nasal cavity with the pterygopalatine fossa.