Supernumerary tooth in nasopalatine canal: a rare cause of septal cartilage collapse

Background

An odontogenic cause for unilateral sinusitis is common, however, a tooth or tooth-like mass is a very uncommon cause of nasal passage air-flow obstruction, especially resulting in septal abscess and cartilage collapse.1 Supernumerary teeth can be located in nasal cavity and paranasal sinuses. Intranasal retained supernumerary tooth is relatively rare, described between 0.1% and 1% in the general population.2 3 Mesiodens is the most common type of supernumerary teeth and is located between two maxillary central incisors in close relation to nasopalatine canal (also known as incisive canal and anterior palatine canal). This can cause nasal obstruction due to surrounding mucosal inflammation and mass effect.2 4 It can occur as an isolated entity or as a part of a syndrome such as Gardner’s syndrome, cleidocranial dysostosis, cleft lip and palate.4

A similar lesion that can be presented in the nasal floor is odontoma, which is a hamartoma that is formed from completely differentiated epithelial and mesenchymal cells that give rise to ameloblasts and odontoblasts. Two types are recognised: compound and complex, both types have been reported presenting in nasal floor.5 6

Common nasal symptoms are unilateral nasal obstruction, nasal discharge, epistaxis, septal abscess and crusting; however, often patients are asymptomatic.2 3 It is conceivable that varying degrees of septal cartilage destruction can occur following infection, although we have not come across cases describing septal collapse in such cases.

Case presentation

A 20-year-old man presented to our otolaryngology department following a 2-year history of right-sided nasal obstruction and discharge that was occasionally blood stained. He had previously been seen in two different otolaryngology clinics and had been treated with intranasal steroids. He was otherwise fit and well with no history of any previous rhinological procedures. One year ago, he experienced a popping sound and a significant amount of mucopurulent discharge from the right nasal passage. At the time, he did not have fever or any other systemic symptoms. He had no history of nasal trauma or use of any illicit drugs and no symptoms of atopy or vasculitis.

On examination, there was a significant collapse of the nasal dorsum and some inflammation in anterior aspect of the nasal septum bilaterally. He also had a swelling in the floor of right nasal passage, the inferior turbinate (IT) was partially adherent to the septum that was causing obstruction and difficulty to examine the right nasal passage beyond it with rigid nasal endoscope. Left nasal passage was normal, including the postnasal space.

Investigations

Tests were commenced to investigate the nasal floor mass and the cause of the septal collapse.

Serological testings (Anti Proteinase 3 (Anti PR-3), and Anti-Myeloperoxidase antibody (Anti MPO), serum Angiotensin-converting enzyme (ACE), plasma viscosity (PV), white cell count (WCC), renal function) were all normal. Syphilis and HIV testing were also negative, with normal chest X-ray.

CT sinuses (figure 1) revealed heavily calcified mass of tuberculate shape with soft tissue thickening in the right IT/meatus with dilated nasopalatine canal and nasal septum defect. MRI sinuses (figure 2) revealed prominence of the right IT with central area of signal void but no mass in nasal floor and collapsed nasal septum.

Differential diagnosis

Differential diagnosis of a nasal floor mass includes foreign body, rhinolith, exostosis, odontoma, osteoma, malignant tumour, calcified polyp and a dermoid cyst.

The most specific tests to differentiate between these nasal floor masses are CT and/or MRI sinus scans and histopathology.

Differential diagnosis for septal cartilage collapse includes trauma, septal abscess, cocaine use, syphilis, sarcoidosis, granulomatosis with polyangiitis or malignant tumour.

To differentiate between these causes for septal cartilage collapse blood tests for infections (WCC, C reactive protein, syphilis tests), chronic inflammatory and autoimmune conditions (PV, Anti MPO, Anti PR-3, serum ACE, renal function), urine tests for suspected illicit drug use (cocaine), radiological imaging (CT sinus, MRI sinus, chest X-ray/CT) and histopathology reports are required to obtain the diagnosis.

Treatment

Preoperatively the patient was prescribed intranasal steroid fluticasone (Avamys) spray 55 μg once-a-day in both the nostrils and nasal douching or rinsing with sodium bicarbonate and salt solution water.

The patient underwent day-case endoscopic removal of intranasal mass for diagnostic purposes. For better access to the mass, the anterior attachment of the IT was divided, and the IT was then reflected into the postnasal space. The mass was mobile with inflamed overlying mucosa (figure 3B,C). The overlying mucosa was incised with a margin of 5 mm around it and send as a separate specimen.

During the surgical procedure multiple biopsies were taken. The IT was sutured back to the anterior stump and the mucosa was relayed onto the nasal floor. A turbinectomy was not performed to reduce the risk of atrophic rhinitis and help maintain the normal function of the nose.7 Intranasal absorbable packing PosiSepX was used to line the nose with a silastic splint in the right nasal cavity.

Given the uncertainty regarding the diagnosis, the septal cartilage collapse was not addressed at the time of this procedure.

Outcome and follow-up

The histology report of the mucosa and septal biopsies showed acute on chronic inflammation with no signs of vasculitis or malignancy. Nasal mass histology showed tubular dentine lined by acellular cementum with a present pulp chamber and focally attached fibroconnective tissue which is lined by stratified squamous epithelium (figure 4), which suggested it to be a supplementary tooth.

Based on the presentation, imaging findings, macroscopic appearance and histology, diagnosis was made of a tuberculate type of mesiodens.

Postoperatively the patient was instructed to use Naseptin nasal cream which contains chlorhexidine with neomycin and nasal douching three times a day until review in clinic 3 weeks from the operation. At the first follow-up clinic the intranasal splint was removed. On examination nasal mucosa was healing well. The patient was instructed to continue with nasal douching and Naseptin cream until further review in 6 weeks.

Based on the history of the septal cartilage collapse with right-sided mucopurulent discharge, endoscopic findings of right IT being adherent to septal cartilage and underlying mesiodens with two tubercles, we believe the patient developed a septal abscess secondary to infection in nasal mucosa surrounding mesiodens that caused the septal cartilage collapse.