Clinical examination and detection of perforation
Diagnosis begins with taking a medical history and performing a thorough examination. The physician must carefully examine the teeth and periodontium on the affected side. If a fistula has formed, probing of the oroantral communication may reveal displacement of a polyp and discharge of purulent contents from the maxillary sinus into the oral cavity.
Since perforative sinusitis accounts for a significant proportion of odontogenic lesions, it is critically important to timely recognize the signs of sinus floor perforation (oroantral communication):
- Immediately after tooth extraction: a bloody air bubble may emerge from the socket.
- Delayed symptoms: the patient complains of liquid food passing from the oral cavity into the nose.
- Socket probing: the instrument enters the sinus cavity without resistance. In chronic cases, the fistula may be covered by a polyp, which must be carefully lifted.
To confirm perforation, air tests are used. The patient is asked to pinch their nose and exhale—if a defect is present, air whistles out through the socket. The cheek-puffing test is also used: due to air leakage into the sinus and nose, the patient cannot puff out their cheeks.
Important: tests may be false-negative if the communication is closed by granulation tissue acting like a valve, or if the socket communicates only with an isolated cavity of a radicular cyst.
Radiological and instrumental diagnostics
The baseline method is radiography of the paranasal sinuses in the Waters' projection. Normally, the sinus appears air-filled. During inflammation, opacification is determined on the image (which appears as a light area on the radiograph itself). An acute process causes total opacification, whereas in chronic processes, opacification persists stably despite antibiotic therapy, and polyp contours or foreign bodies may be visualized.
Additional methods are used for a comprehensive assessment:
- Orthopantomography (OPG): does not show sinusitis itself, but excellently demonstrates the condition of the bone walls, periodontium, presence of radicular cysts, quality of endodontic treatment, and filling material pushed beyond the root apex.
- Intraoral radiography: indispensable for targeted searching for root remnants in the extracted tooth socket.
- Computed tomography (CT): the most informative method (axial projection with coronal reconstruction). CT shows the exact volume of polypoid-altered mucosa and identifies specific odontogenic sources of infection (e.g., destruction foci due to severe periodontitis of teeth 16 and 17). In complex cases, CT replaces both overview radiography and OPG.
- Endoscopy (sinuscopy): performed through the fistulous tract using a fiberscope. It allows visual assessment of the mucosa and targeted biopsy.
Laboratory methods and electric pulp testing
To plan effective pharmacotherapy, microbiological examination of the exudate is necessary. Material is collected by sinus puncture through the inferior nasal meatus or directly through an existing oroantral communication. This allows determination of the species composition of pathogenic microflora and its antibiotic sensitivity.
In parallel with radiological examination, it is advisable to perform electric pulp testing (EPT). This method allows an objective assessment of the vitality of the pulp of maxillary premolars and molars, which is necessary for deciding the fate of the teeth during preoperative preparation.
Differential diagnosis
The main task of differential diagnosis is to distinguish the odontogenic process from rhinogenic ones. Despite similar symptoms (including headache), they differ radically in treatment approaches. Rhinogenic sinusitis is usually bilateral, whereas odontogenic affects the sinus maxillaris on only one side and is always accompanied by a periapical source of infection.
In addition, the physician must maintain oncological vigilance. On radiographs, shadows from radicular cysts, aspergillomas (colonies of the mold fungus Aspergillus), or foreign bodies can mask more serious pathologies. A strong sign of a malignant neoplasm is the destruction of the sinus bone walls, but the final diagnosis is established solely based on pathohistological examination.
Briefly: answers to topical questions
Which maxillary teeth are most frequently the cause of odontogenic maxillary sinusitis?
The cause of odontogenic maxillary sinusitis is most frequently maxillary premolars and molars.
In particular, the source of infection may be:
- Molars—teeth 16 and 17, for example, in cases of bone tissue destruction foci due to severe periodontitis.
- Premolars are teeth 15, 14, 24, 25. The first premolars typically have two roots, while the second premolars often have two canals; the proximity of the maxillary sinus creates a risk of its perforation during surgical intervention.
What are the clinical and anamnestical differences between odontogenic and rhinogenic maxillary sinusitis?
Odontogenic maxillary sinusitis differs from rhinogenic sinusitis in the nature of the lesion and the presence of an odontogenic source of infection. The clinical symptoms of both conditions are similar, including the presence of headache, but there are key differences.
| Sign | Odontogenic sinusitis | Rhinogenic sinusitis |
|---|---|---|
| Nature of the lesion | Usually unilateral | Usually bilateral |
| Source of infection | A periapical source of infection is identified | — |
What surgical methods exist for the plastic repair and closure of an oroantral communication?
The following surgical methods are used for the plastic repair and closure of an oroantral communication:
- Buccal flap — closure of the socket with a well-mobilized mucoperiosteal flap harvested from the buccal side; a trapezoidal buccal flap is also used.
- Full-thickness palatal flap.
- Subepithelial palatal flap — plastic repair using a split subepithelial vascularized palatal flap; wound healing occurs by primary intention.
- Palatal mucosal autograft.
A less effective method is the closure of the orifice with an iodoform gauze packing, which only covers the socket orifice.
What radiological signs are characteristic of a malignant neoplasm of the maxillary sinus?
Malignant neoplasms of the maxillary sinus are characterized by radiological signs of bone tissue destruction with blurred margins. The presentation depends on the stage of the tumor process.
The following radiological signs are distinguished:
- Early stages — opacification of the maxillary sinus and thinning of its walls.
- Late stages — destructive changes in the walls (a strong sign of malignancy). In advanced cases, the contours of the sinus are not traceable due to their complete destruction.
- Bone destruction — occurs without the formation of sequestra; the borders of the lesion are blurred.
- Involvement of the alveolar process — intraoral radiographs show unclear bone contours, a moth-eaten appearance, and a marginal defect with blurred margins.
Differences in sinusitis: Rhinogenic — Evenly on Both sides. Odontogenic — Focus on One.
What else to study on this topic
- Conservative treatment of acute odontogenic sinusitis
- Surgical tactics for uncomplicated oroantral communication
- Algorithm of actions when a tooth root is pushed into the sinus
- Technique of radical antrostomy according to Caldwell–Luc
- Local anesthesia protocol for surgeries on the maxillary sinus
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