A sinus perforation, also known as an oroantral communication (OAC), is an abnormal opening between the oral cavity and the maxillary sinus, the large air-filled space beneath the cheekbone. This complication most frequently arises following the extraction of an upper back tooth, such as a molar or premolar, because the roots often lie close to the thin bony floor of the sinus cavity. When this barrier is breached, a direct connection allows bacteria and fluids to pass between the mouth and the sinus. Recognizing this connection quickly is important, as an untreated perforation can lead to chronic sinusitis and the development of an oroantral fistula.
Recognizing Subjective Signs
A patient’s first indication of a perforation is often the sensation of air moving between the mouth and the nose through the extraction site. This air movement may manifest as a noticeable whistling sound when speaking, breathing, or swallowing. Another specific symptom is the nasal regurgitation of liquids. This occurs when liquid leaks through the perforation into the maxillary sinus and then drains out of the nostril on the affected side. Patients may also experience hypernasality due to altered air pressure dynamics. Other localized symptoms include pressure or congestion on one side of the face, a persistent unpleasant taste, or a foul odor originating from the extraction site.
Clinical Confirmation Tests
Professionals rely on specific physical maneuvers to confirm the presence of a suspected perforation.
Nose-Blowing Test
The most recognized test is a modified Valsalva maneuver, often called the nose-blowing test. The patient is instructed to gently close their nostrils and attempt to exhale softly through the nose while keeping their mouth slightly open. A positive result is the observation of air, or small bubbles of blood or fluid, escaping through the tooth socket. The gentle nature of this test is stressed, as excessive force can dislodge a forming blood clot or enlarge the opening.
Mirror Test
A simpler objective test is the mirror test, where a cool mouth mirror is held over the extraction site. If a perforation exists, the air escaping from the sinus will fog the mirror’s surface.
Diagnostic Imaging for Assessment
While clinical tests confirm the presence of an opening, diagnostic imaging is necessary to assess the perforation and surrounding structures.
Standard Radiographs
Standard two-dimensional dental X-rays, such as periapical films and panoramic radiographs, are often the initial step. These images can show a discontinuity in the bony floor of the maxillary sinus and may reveal signs of secondary infection, such as thickening of the sinus lining, known as the Schneiderian membrane.
Cone-Beam CT (CBCT)
For a detailed view, Cone-Beam Computed Tomography (CBCT) is used. A CBCT scan provides cross-sectional images that precisely determine the perforation’s size, location, and the condition of the soft tissue within the sinus. This imaging guides treatment planning, as the required surgical technique depends on the defect’s size; communications larger than five millimeters typically require surgical closure.
Immediate Steps Following Detection
If a sinus perforation is suspected or confirmed, immediate and strict adherence to specific precautions is important to prevent complications. The primary goal is to avoid creating pressure differences between the mouth and the nose that could dislodge the blood clot or force contamination into the sinus.
Patients must refrain from blowing their nose entirely for an extended period. Any action that causes suction or pressure should be avoided, including using drinking straws, spitting, or smoking. If the patient feels the need to sneeze, they should do so with their mouth wide open to release the pressure outward, rather than directing it into the sinus. Prompt consultation with an oral surgeon is necessary, as small perforations (less than two millimeters) may heal spontaneously with conservative management, but larger ones require surgical closure using sutures or a flap technique.