INTRODUCTION

• The nasopalatine duct cyst (NPDC) was first ever described by Meyer in 1914.
• Nasopalatine duct cyst is also termed as incisive canal cyst, arises from embryogenic remnants of nasopalatine duct
• Most of these cysts develop in the midline of anterior maxilla near the incisive foramen.
• It is one of the most common nonodontogenic cysts of the oral cavity occurring in about 1% of the population

ETIOLOGY

• The cyst originates from epithelial remnants from the nasopalatine duct.
• The cells may be activated spontaneously during life or are eventually stimulated by the irritating action of various agents (infection, etc.).

EPIDEMIOLOGY

• Nasopalatine duct cysts are the most common non-odontogenic cyst found within the anterior maxilla.
• There is a 3 to 1 predilection for males; however, there is no significant correlation between the size of these cysts and the patient’s gender.

CLINICAL FEATURES

• Age predilection : fourth to sixth decades of life.
• Gender predilection : common in men.
• Patients may be asymptomatic, with the lesion being detected on routine radiographs; however, many will present with one or more symptoms.
• Complaints are often found to be associated with an infection of a previously asymptomatic nasopalatine duct cysts and consist primarily of swelling, drainage, and pain.

RADIOGRAPHIC FEATURES

• Almost all nasopalatine cyst occurs within the incisive canal at any level between nasal and oral cavity
• Teardrop shaped and show a well demarcated slightly sclerotic border
• Some cyst have an inverted pear shaped
• Superimposition of the nasal spine classic heart shape

HISTOLOGICAL FEATURES

• The cyst is lined by respiratory type of epithelium
• The cyst is surrounded by fibrous capsule exhibiting a mild degree of chronic inflammation

EVALUATION

• Nasopalatine duct cysts present histologically with an epithelial-lined cyst wall surrounded by fibrovascular connective tissue, oftentimes with minor salivary glands as incidental findings.
• Vitality testing must be performed on teeth associated with the lesion to rule out an odontogenic source, such as a periapical cyst or granuloma.
• Teeth associated with a nasopalatine duct cyst will test vital.

DIFFERENTIAL DIAGNOSIS

• Any odontogenic cyst (lateral periodontal cyst and periapical cyst/granuloma)
• Enlarged incisive fossa
• Central giant cell granuloma

TREATMENT

• Nasopalatine duct cysts are best treated by surgical resection.
• After removal, it is important to monitor patients both clinically and radiographically to determine if the lesion has completely resolved.
• Recurrence is rare

PROGNOSIS

• Nasopalatine duct cysts have an excellent prognosis with rare recurrence.
• The biopsy usually reveals adequate treatment (complete excision).