Table of Contents
Introduction:
The two common conditions of the maxillary sinus that is maxillary sinusitis (an inflammatory condition) and maxillary sinus retention cysts (a soft, dome-shaped, non-cancerous cyst that occurs on the inside of the maxillary sinus wall) are asymptomatic and have similar features. These can be identified on routine dental radiographic examinations. This article sheds light on the features of the largest paranasal sinus of our face, that is, the maxillary sinus, and explains how to differentiate the clinical symptoms or features of maxillary sinus retention cysts from that of maxillary sinusitis. Also, whether these sinus conditions require in-depth management by the dentist or maxillofacial surgeon is explained.
What Are the Features of the Maxillary Sinus?
The maxillary sinus in the medical literature is commonly known as the antrum of Highmore. It is the largest of all the paranasal sinuses in our body. The description of this sinus was first given by a revered physician and anatomy specialist named Nathaniel Highmore. The maxillary sinus is rather pyramidal and is hollow spaced just like any other body sinus. It acts as a protective zone for the human orofacial cavity against injury or external trauma. Though present at birth, the maxillary sinus keeps on developing till the age of 14. The maxillary sinus also reduces the weight of the human facial skeleton while additionally imparting a resonant quality to the voice box.
The sinus is always lined by a mucus layer similar to that of the mucus lining present in the nasal cavity or passages. The function of these mucus layers is to trap foreign particles, dirt, or dust, and are moist in nature. When the maxillary sinus gets either bacterially or virally infected (which is the most common reason for the occurrences of all sinus infections), then the moist mucus layers also get inflamed. The extent of inflammation depends upon the extent of injury or the bacterial or viral infection that invades it.
What Are the Symptoms of Maxillary Sinusitis?
The symptoms of sinusitis manifest gradually usually within a week causing upper respiratory tract infections. These upper respiratory tract infections are often very acute in occurrence and clinical symptoms and severity manifest within a short period. The following are some of the symptoms that one must watch out for when one suspects a potential maxillary sinus infection:
- Unexplained orofacial (related to the mouth and face) pain.
- General malaise or fatigue.
- Fever or pyrexia.
- Frequent headaches.
- Blocked nose or obstruction in the nasal cavity.
- Smelly or purulent nasal discharge that is of a mucus consistency.
- Throbbing pain in the posterior upper teeth like upper premolars or molars. Sometimes, the pain can be dull as well.
- Increased sensitivity of the teeth to any kind of stimulus mainly hot, sweet, and cold stimuli.
- Upon mastication or chewing, the patient often observes an exacerbation of tooth pain without having any associated dental infections or cavities.
- Pain increases when one bends the head downwards.
- Sudden tenderness of the cheek area or the periorbital region (in and around the orbit or the maxillary canine region) may be experienced.
- In rare cases, there may be additional swelling or inflammation of the cheek which could be chronic.
- Patients may notice that sinusitis infections may be nonresponsive to certain antibiotic medications or therapies prescribed by the dental or oral surgeon.
What Are Maxillary Sinus Retention Cysts?
Maxillary sinus retention cysts are observable, soft, dome-shaped masses that develop usually at the bottom and on the inner walls of the maxillary sinus. Maxillary sinus retention cysts or MSRC are very commonly observed yet asymptomatic cystic lesions or infections found in the maxillary sinus that are incidentally found on dental radiographs. This would be a dental observation rather than a pathologic finding since most cases get a coincidental detection when the dentist takes a radiograph of the maxillary sinus or while making a treatment plan for the placement of a dental implant.
The retention cysts have been found to penetrate the bony walls of the sinus or protrude further into the middle meatus (an air passage of the lateral nasal cavity that is situated between the middle nasal concha and the lateral nasal wall) region.
The reported prevalence rates for these retention cysts usually vary from 1.6 percent to 7.4 percent globally while the majority of lesions remain unchanged and no treatment as such would be recommended. If the cysts do not present with any clinical symptoms (which holds for most of the asymptomatic cyst cases), then the dentist may recommend periodic imaging through dental panoramic radiography or CT (computed tomography) scanning or CBCT (cone-beam computed tomography) to observe whether the lesions have the potential for further growth.
However, when the maxillary retention cysts exceed a size greater than 0.78 inches or if they are bilaterally present, then they are at a greater risk of progression and can obstruct the natural ostia of the maxillary sinus. This depends on the individual systemic and local factors that remain elusive to research. Maxillary sinus retention cysts are lesions that develop on the inner walls of the maxillary sinus and are not inflammatory, cysts unlike the maxillary sinusitis.
What Are the Symptoms of Sinus Retention Cysts?
The symptoms of sinus retention cysts are different and are not very noticeable or bothersome to the patient. The individual may feel only a few of the following features:
- Slight tingling or numbness in the face.
- Dizziness.
- Chronic headaches.
- Mild tooth sensitivity in the upper posterior region (premolars or molars region) and sometimes may be accompanied by pain.
- Nasal obstruction.
How Are Maxillary Sinusitis and Sinus Retention Cysts Managed?
Large maxillary sinus retention cysts larger than 0.78 inches can easily be treated by minor endoscopic surgery procedures. A smaller sinus retention cyst may need only periods of imaging or regular dental follow-ups and usually does not require any management. Management usually involves a minor surgical procedure called enucleation wherein the entire cystic lesion is removed without rupturing the cyst.
Surgical curettage is another option for large sinus retention cysts where specialized loop instruments are used to curette the cyst contents. Prognosis and healing are excellent for maxillary sinus retention cysts since the patient does not experience any clinical symptoms, unlike the erosive or inflammatory nature of maxillary sinusitis.
Maxillary sinusitis however needs a definite treatment plan and is usually treated by the oral surgeon initially by nonsurgical means. However, in cases where the infection does not subside with medications, then a maxillary antrostomy (a surgical procedure wherein the opening of the maxillary sinuses is widened) procedure would be needed to drain the infection. In severe or chronic cases of maxillary sinusitis, where even an antrostomy procedure cannot drain the sinus infection completely, then the most preferred and oldest surgical technique will be employed by the oral surgeon which is known as the Caldwell-Luc surgery (a procedure in which a drainage pathway is created in between the maxillary sinus and the nose).
Conclusion:
Maxillary sinus retention cysts are common incidental findings on radiographs. Maxillary sinus retention cysts though common are asymptomatic and unless they are large or exceed a certain size, they neither pose any issues nor require any treatment. However, maxillary sinusitis can be a chronic condition that needs timely diagnosis and surgical management at times to prevent upper respiratory tract infections and further progression.
