Introduction:
Dental implantation has revolutionized the field of dentistry, offering patients a reliable and long-lasting solution for missing teeth. However, certain anatomical anomalies and pathological conditions can complicate the implantation process. Antral pseudocysts, also known as maxillary sinus pseudocysts, is one such condition that can pose challenges for successful dental implant placement.
What Is Antral Pseudocysts?
Antral pseudocysts are non-inflammatory, fluid-filled cavities that develop in the maxillary sinus, which is a hollow space that is located above the upper jaw. These cysts are often asymptomatic and discovered incidentally during routine dental or radiographic examinations. While their exact etiology remains unclear, antral pseudocysts are believed to result from sinus membrane elevation due to various factors such as trauma, infection, or retained dental materials.
What Are the Features of the Antral Pseudocyst of the Maxillary Sinus?
Commonly occurring cysts, though not of a true nature affecting the lining of the maxillary sinus, are considered to be 'antral pseudocysts.' The antral pseudocyst (AP) is a common disease entity that affects the largest of the facial sinuses—the pyramidal-shaped maxillary sinus. This cyst can be a prevalent incidental finding on a panoramic radiograph or OPG (orthopantomogram), with prevalence varying from 1.5 percent to 14 percent of the general population. The pseudocyst is caused by an inflammatory process or an exudate that gradually accumulates over time under the lining epithelium of the maxillary sinus. The antral pseudocyst may be known or termed as a well-defined 'dome-shaped' radiopaque lesion observed in the maxillary sinus cavity upon radiographic examination.
Are All Antral Pseudocyst Lesions Asymptomatic?
It is interesting to note that these lesions are usually detected only by chance through routine radiographic assessments at the dental clinic. This is because most antral pseudocysts (APs) are generally asymptomatic. Due to their asymptomatic nature in a vast majority of patients, treatment is considered unnecessary by dental surgeons unless the cyst becomes symptomatic. Although patients affected seldom complain of oral discomfort, they may still experience sinus-related issues or nasal obstruction that they might be ignoring. In untreated cases or in moderate to severe lesions of the antral pseudocyst, patients may exhibit clinical features similar to those of sinusitis, such as headaches, postnasal drip, and, in some cases, even tooth pain (posterior teeth of the upper jaw).
How Does the Presence of This Cyst Pose a Challenge to the Implantologist and Interfere With the Placement of Dental Implants?
The presence of an antral pseudocyst poses clinical challenges and complications for the implant dentist, especially when a dental implant needs to be placed in an edentulous (toothless) posterior maxillary segment. Patients often require maxillary sinus augmentation surgery to gain sufficient bone volume before placing a dental implant in the posterior maxilla, such as for dental molar or premolar implants.
This is because most posterior maxillary implants require the maxillary sinus floor to be augmented before dental implant placement. In such cases, performing sinus augmentation can be very challenging, as the sinus lumen may be further reduced after this procedure, and the ostium of the sinus may be completely obstructed, posing clinical complications. Additionally, if the antral pseudocyst itself is perforated during sinus augmentation, the cystic contents can flow outwards, causing contamination or a breach during the augmentation surgery. This can lead to the failure of the procedure itself, and new bone may not form effectively even after the augmentation surgery.
Why Recording Medical History Is Important in Patients With Antral Pseudocyst?
The medical history of patients reporting with antral pseudocyst needs to be recorded by the dental or the oral surgeon. This is important because medical research suggests that these patients may have common underlying systemic diseases such as cardiovascular disease, hypertension, allergic rhinitis, or ENT (ear. nose, and throat) diseases.
What Are the Steps in the Surgical Resection of a Cyst?
The following steps are implemented in the surgical resection or removal of the oro-antral pseudocyst:
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Prior to treatment, the dentist, oral surgeon, or implant surgeon needs to determine the patient's medical history and discuss any pharmacologic interventions or therapies that they are on with their professional healthcare provider.
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Surgical resection of the antral pseudocyst can then be performed by the oral surgeon under local anesthesia with the help of intravenous sedation if needed.
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A vertical incision is usually made at the level of the vestibular oral sulcus, and a mucoperiosteal flap will be elevated to expose the surgical site.
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The oral surgeon prepares the antrostomy site with a diameter of approximately 0.39 inches on the frontal wall of the sinus using a diamond round bur. Sometimes, intentional perforation of the sinus membrane can also be performed.
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The wall of the cystic lesion is clamped with forceps and then herniated through the prepared sinus window with a gentle outward force or traction by the surgeon. This is done to preserve the integrity of the periosteum or underlying bone layers beneath the cystic lesion.
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The antrostomy site is then well-covered using a resorbable collagen membrane, ideally to reduce the inflow of blood back into the sinus cavity. The mucoperiosteal flap is eventually closed.
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Antibiotic prophylaxis is then given or advised by the oral surgeon or dentist. Azithromycin hydrate (500 mg) is usually the preferred choice of antibiotic to be administered preoperatively at least one hour before the surgery and then repeated post-surgery for two to three days, with the dosage as needed and prescribed by the surgeon. Loxoprofen sodium hydrate (60 mg) is usually the preferred choice of painkiller for preventing postoperative pain.
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Postoperative instructions are given in detail by the oral surgeon to the patient, and the possibility of epistaxis or bleeding from the nose may exist for a few days post-surgery. Hence, patients should be instructed to avoid blowing their nose until the wound healing is complete and to avoid pressure on the maxillary sinus lining.
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The removed or resected cystic tissue is usually sent for histopathological examination to determine its nature and extent.
Conclusion:
The antral pseudocyst may be a unique and clinically challenging lesion that needs to be eliminated when it exhibits symptoms of sinusitis or poses complications for dental implant placement in the edentulous posterior maxilla. Whether for sinus augmentation surgery or surgical resection of the antral pseudocyst, preoperative evaluation, usually by cone beam computed tomography (CBCT) or an OPG (orthopantomogram), is preferred by the oral surgeon. To avoid complications in placing dental implants, it is ideal to completely eliminate the antral pseudocyst. According to dental surgeons, in cases where no clinical symptoms exist, treatment may be unnecessary until any clinical features occur.
