Anatomy

The uncinate process is shaped like a rudder (Fig. 5.9);

its superior extension can do one of the following:

• Merge with an agger nasi air cell or the lateral nasal wall to form a blind-ended pocket called the sulcus terminalis.

• Insert into the skull base, forming an overhang that can limit anterior access to the frontal recess.

• Insert into the middle turbinate and form a web that guards the frontal recess.

Middle Turbinate Anatomy

Fig. 5.3 Line diagram showing the area to be removed in a maxillary sinusotomy of bone and mucosa type I.

Fig. 5.3 Line diagram showing the area to be removed in a maxillary sinusotomy of bone and mucosa type I.

Sinusotomy

Fig. 5.4 Line diagram showing the area to be removed in a maxillary sinusotomy of bone and mucosa type II.

Fig. 5.4 Line diagram showing the area to be removed in a maxillary sinusotomy of bone and mucosa type II.

Sinusotomy
Fig. 5.5 Line diagram showing the area of bone and mucosa to be removed in a maxillary sinusotomy type III.

Fig. 5.6 a Endoscopic view of circulating mucus between an incomplete opening of the anterior natural ostium and a large posterior ostium. b The coronal CT scans show the obstructed natural anterior ostium and c the wider posterior ostium, away from the natural ostium.

Sinus Mycetoma
Fig. 5.7 a Endoscopic view of a mycetoma in the right maxillary sinus. b Coronal CT scan of the patient.
Coronal Cat Scan View Sinusitis
Maxillary Sinusotomy
Fig. 5.8 a The maxillary sinusotomy is extended below the margin of the middle turbinate to help ensure that mucociliary clearance can take place. b A line diagram of a.
Maxillary Sinusotomy
Fig. 5.9 A disarticulated right uncinate process.
Uncinate Process Insertion
Fig. 5.10 The uncinate process (arrow) has been lifted forward to reveal the natural ostium of the maxillary sinus. The green wire is in the position of the infundibulum of the anterior ethmoid sinuses.

The uncinate process "guards" the natural maxillary ostium to form a slitlike corridor to it, the infundibulum ethmoidale (Fig. 5.10). The entrance to this corridor is the hiatus semilunaris (anterior), a crescent-shaped space at the posterior edge of the uncinate process (Fig. 5.11). The uncinate process is made up of very thin bone that attaches anteriorly to the bone adjacent to the nasolacrimal duct, so it is important not to come too far forward when removing the uncinate process. It extends upward to insert into the lateral nasal wall in approximately 70% of patients and into the skull base or the middle turbinate in the remaining 30%. The insertion of the uncinate process determines whether the frontal sinus drains directly into the middle meatus (type A) or into the infundibulum ethmoidale lateral to the uncinate process (type B) (Fig. 5.12).

The uncinate process is normally in a sagittal plane, although polyps in the infundibulum can push its post-

Infundibulum Ethmoidale
Fig. 5.11 A window has been made in the middle turbinate to reveal the edge of the uncinate process (arrow), the hiatus semilunaris, and the ethmoid bulla (*).
Paradoxical Turbinate

Fig. 5.12 This shows a type A uncinate process (left), where the frontal sinus drains directly into the middle meatus, and types B1 (center),where the uncinate process attaches to the skull base, and B2 (right), where the uncinate process attaches to the middle turbinate. Both B1 and B2 have the frontal sinus draining into the infundibulum ethmoidale.

Fig. 5.12 This shows a type A uncinate process (left), where the frontal sinus drains directly into the middle meatus, and types B1 (center),where the uncinate process attaches to the skull base, and B2 (right), where the uncinate process attaches to the middle turbinate. Both B1 and B2 have the frontal sinus draining into the infundibulum ethmoidale.

Hypocretin Anatomy

Fig.5.13a-c Palpating around the edge of the uncinate process with a ball probe.

Paradoxical Turn Left Middle Turbinate

Fig.5.13a-c Palpating around the edge of the uncinate process with a ball probe.

erior edge medially. In less than 1 % of healthy individuals, it can be paradoxical, curving forward on itself. It rarely contains a pneumatized cell. It is very thin and any incision through it only needs to be about 1 mm; any more and it could go through other structures that are more lateral to it.These maybe anterior ethmoid air cells, but in many patients there are no cells between it and the orbit. Inferiorly, it is attached to the base of the inferior turbinate, and together these fill most of the bony defect of the medial wall of the maxillary sinus. The remainder of the medial wall of the maxillary sinus has no bone and is made up of mucosa. It forms the anterior and posterior fontanelles. It is possible to ballotte these areas that consist solely of mucosa with a curved, olive-ended sucker to help locate them. An anterior branch of the sphenopalatine artery runs in the medial wall of the maxillary sinus and is sufficiently large that opening the maxillary ostium posteriorly to within 0.5 cm of the posterior wall of the maxillary sinus will lead to bleeding.

Middle Turbinate Anatomy
b
Paradoxical Right Turbinate
Fig. 5.14a-d The backbiter is fed around the edge of the uncinate process and an inferior horizontal bite is taken.

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Responses

  • GENET NEGASSI
    How turbinate is formed?
    8 years ago
  • chantelle findlay
    What could happen if middle turbinates are removed?
    8 years ago
  • sharon culbertson
    What if your middle turbinate is removed?
    7 years ago
  • SEMRET
    Is the uncinate the middle turbinate?
    2 months ago

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