Etiology and routes of infection
The primary source of infection is the microflora causing acute or chronic periodontitis. The risk of the inflammation spreading to the sinus is especially high in the pneumatic type of sinus structure, where the tooth roots are separated from the mucous membrane only by a thin bony plate or even directly adjoin it.
Several pathways of odontogenic infection spread are distinguished:
- Direct contact: the inflammatory process spreads directly from the periapical tissues with the destruction of the bony septum.
- Hematogenous: the infection is transmitted via the general microcirculatory bed of the maxillofacial system and the sinus.
- Iatrogenic (subjective): occurs due to the physician's fault. During endodontic treatment, filling material, gutta-percha points, or gangrenous decay may be pushed into the sinus. During surgical intervention, traumatic extraction or curettage of the socket can lead to the root being pushed into the sinus.
Pathogenesis and morphological changes
Normally, the sinus is lined with pseudostratified ciliated columnar epithelium. The cilia make about 1,400 beats per minute, directing mucus toward the natural ostium. During inflammation, the cilia slow down and eventually die. This disrupts aeration and the outflow of exudate, creating ideal conditions for the proliferation of anaerobic microflora.
The pathomorphological picture depends on the stage of the process:
- Epithelium: desquamation is observed up to the formation of ulcers, areas of necrobiosis are replaced by stratified squamous epithelium. In the polypoid form, outgrowths are formed.
- Blood vessels: dilate and become engorged with blood, the walls become loose and undergo sclerosis, and hemorrhages occur.
- Infiltrate: the mucosa is infiltrated with histiocytes, lymphocytes, and plasma cells. Microabscesses form.
Fibrosis and sclerosis phenomena gradually increase. If the inflammation is maintained through an oroantral communication, the fistulous tract becomes lined with stratified squamous epithelium with signs of acanthosis, and the bony walls react with hyperostosis.
Clinical presentation
Odontogenic sinusitis is characterized by diverse manifestations, but most often proceeds in a chronic form with mild symptoms (sometimes latently) and is unilateral in nature.
Acute form (or exacerbation):
- Pain and a feeling of heaviness in the affected half of the face with radiation to the temple, forehead, or back of the head.
- Pain in the "causative" teeth upon percussion and biting.
- Nasal congestion, hyposmia, or anosmia.
- Initially scant mucous, and then profuse seropurulent nasal discharge (outflow reduces pain).
- Intoxication syndrome: fever (above 37.5 °C), weakness, chills.
Chronic form:
- Pain syndrome subsides, a feeling of heaviness remains.
- Periodic mucopurulent discharge with an unpleasant, putrid odor.
- Persistent nasal breathing disorder.
- Normal or low-grade fever.
Oroantral communication (perforation)
Objective prerequisites for perforation of the sinus floor during tooth extraction include the pneumatic type of sinus structure and inflammatory bone destruction.
According to the duration of existence, the communication is divided into:
- Perforation: exists for no more than 21 days.
- Fistulous tract: exists for more than 21 days (the socket epithelializes, and a persistent fistula forms).
Diagnosis uses air tests. When attempting to puff out the cheeks (with the nose open), the patient is unable to do so — air escapes through the perforation. On exhalation with the nose closed, air or purulent exudate is expelled from the socket of the extracted tooth.
Treatment tactics depend on the condition of the sinus. Plastic closure of the communication without radical antrostomy is possible only in the absence of purulent discharge and a history of chronic inflammation, as well as with timely antibiotic therapy. Spontaneous healing of the perforation is a clinical exception.
To memorize the classification of communication by time: "Up to three weeks — just a perforation, after — a persistent fistula (fistulous tract) with epithelialization."
Class and exam questions
Why does infection easily penetrate the sinus from the teeth?
In the pneumatic type of maxillary sinus structure, the roots of the molars and premolars are separated from the mucous membrane by only a very thin bony plate, and sometimes lie directly against it.
How does the sinus epithelium change during inflammation?
Pseudostratified ciliated epithelium loses its cilia and desquamates. Areas of necrobiosis are gradually replaced by squamous epithelium, and polyps and microabscesses may form.
How to check for perforation using air tests?
The patient is asked to blow out their cheeks — if a communication is present, air escapes through the nose. They are also asked to exhale through a closed nose — in this case, air bubbles or exudate are released from the tooth socket.
What else to study on this topic
- Radiological signs (OPG, direct skull projection)
- Indications and technique of radical antrostomy surgery
- Methods of plastic closure of the oroantral communication
- Analysis of clinical cases with foreign bodies (filling material, drainage)
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