Chapter 8. Odontogenic Maxillary Sinusitis

Classification

Maxillary sinusitis - is a disease caused by an inflammatory process in the mucous membrane of the maxillary sinus.

The following types of maxillary sinusitis are distinguished.

• Depending on the route of infection in the maxillary sinus:
  • rhinogenic (rhinitis, flu);
  • hematogenic (pneumonia, diphtheria, typhus);
  • traumatic (penetrating wounds of the maxillary sinus);
  • odontogenic (from the ‘causal’ tooth);
  • perforative (during tooth extraction).
• By the prevalence of the process:
  • limited;
  • diffuse.
• By the localization:
  • one-sided;
  • two-sided.
• By the flow of the process:
  • acute;
  • chronic;
  • chronic with an exacerbation.
• By the nature of the inflammatory reaction:
  • exudative (catarrhal, serous, suppurative);
  • productive (polyposis, non-polyposis).

According to the ICD-10 classification, odontogenic maxillary sinusitis is classified as a Respiratory disease (J00-J99).

• J01.0 Acute maxillary sinusitis (acute antritis).
• J32.0 Chronic maxillary sinusitis (chronic antritis, maxillary sinusitis without any other indications).

In the case of a violation of the integrity of the bottom of the maxillary sinus in the process of an extraction of the upper teeth and the formation of a perforation or fistula, a perforative maxillary sinusitis is identified (Robustova T.G., 2006). The complication occurs quite often, although it is not separately identified in the ICD-10.

Odontogenic maxillary sinusitis (sinusitis maxillaris, antritis maxillaris, highmoritis), the occurrence of which is associated with the spread of an infectious and inflammatory process from the foci of odontogenic infection of the upper jaw, is similar in its essence and clinical picture to a sinusitis of a different etiology.

Pathophysiology

The occurrence of an odontogenic inflammatory process in the maxillary sinus is associated with the spread of infection from the diseased teeth ― this is facilitated by the anatomical proximity of the jaw and the sinus. The roots of the teeth of the upper jaw (the premolars and molars) are closely adjacent to the bottom of the maxillary sinus. Normally, the maxillary sinus is located above the root apex of the second premolar and the first and second molars; when it expands posteriorly, it captures the area of the third molar, anteriorly ― the area of the first premolar and (less often) the canine (Fig. 8.1).

Fig. 8.1. The scheme of the ratio of the bottom of the maxillary sinus to the teeth of the upper jaw

The roots of the teeth located in the alveolar process are separated from the bottom of the maxillary sinus by a cortical plate of unequal thickness: it is massive in some patients, and in others, it is so thin that the roots of the teeth are delimited from the cavity of the maxillary sinus only by the periosteum and the sinus mucosa (Fig. 8.2).

Fig. 8.2. Orthopantomogram. The apex of the roots of the first and second molars of the upper jaw are located in the maxillary sinus

The shape of the maxillary sinus is usually compared to a truncated tetrahedral prism. The average sinus volume is from 2.8×15 to 20×40 cm³. The sinus usually consists of one chamber; alveolar inlets protrude into it from the inside, separated by partitions. In relation to the bottom of the nasal cavity, the bottom of an alveolar inlet can be located in different ways: at the same level, above and below it.

The following walls are distinguished in the maxillary sinus: the upper, anterior, medial, posterior and inferior.

• The upper wall of the maxillary sinus partially serves as the lower wall of the orbit. It is the thinnest wall of the sinus.
• The anterior wall of the maxillary sinus extends from the lower edge of the orbit to the alveolar process of the upper jaw.
• The medial (nasal) wall of the sinus is also the outer wall of the nasal cavity. The nasolacrimal canal passes in front of it. Behind the protrusion of the nasolacrimal canal in the highest place of the sinus is the outlet of the maxillary sinus, ostium maxillare. The size of the hole differs: 2-9 mm in length, and 2-6 mm in width.
• The posterior wall of the maxillary sinus corresponds to the maxillary tubercle and, with its posterior surface, faces the pterygopalatine fossa.
• The inferior wall (the floor of the maxillary sinus) is subject to significant variations.

The inner surface of the sinuses is covered with a mucous membrane with a thickness of about 0.1 mm; the latter is represented by a multi-row cylindrical ciliated epithelium, which, among other things, performs a cleansing function. It represents the mucociliary transport system of the nasal cavity and the sinuses, which determines the speed of air flow in them. The ciliated epithelium functions in such a way that the movement of mucus is directed upward in a circle to the medial corner of the sinus, where the anastomosis with the middle nasal passage of the nasal cavity is located. The cilia of the epithelium, which move in the direction of the natural opening of the sinus, are capable of moving particles that are up to 0.5 mm in diameter.

Anatomically, there are three types of maxillary sinuses: pneumatic, sclerotic and combined.

• With a pneumatic type, the dimensions of the sinus are large enough, the walls are thin, the bottom protrudes into the alveolar process, forming inlets. The roots of the large and small molars are separated from the bottom of the sinuses by a plate, and, sometimes, have a direct contact with the mucous membrane lining it. The largest volume of the maxillary sinus is 18.6 cm³.
• A sclerotic sinus has a small volume of up to 2.8 cm³; the bone septum between the sinus mucosa and the apexes of the teeth may have a thickness of 1 cm or more.
• The average volume of a combined sinus reaches 12.1 cm3.