Volume 2, Issue 1 , Pages 17-19, March 2007
Congenital defect of the vomer bone: A rare cause of septal perforation
Article Outline
Summary
Congenital anomalies of the nasal septum besides septal deviation are very rare, and few cases of congenital defect of the vomer have been reported. We present a case of a 13-year-old boy who had a defect in the posteroinferior aspect of the nasal septum that was discovered incidentally during diagnostic work-up for chronic sinusitis. The patient had no history of maxillofacial trauma, drug abuse and had not previously undergone nasal surgery or cautery for epistaxis, and showed no evidence of systemic inflammatory disease. Based on the patient's history and laboratory findings, the septal defect is thought to be due to a congenital defect of the vomer bone.
Keywords: Vomer defect, Congenital, Septal perforation
Introduction
The nasal septum is composed of the vomer, nasal crest of the palatine bone, the nasal crest of maxilla and premaxilla, perpendicular plate of the ethmoid, nasal crest of the frontal bone, the spine of the paired nasal bones and the quadrilateral cartilage [1]. Defects of the nasal septum are most frequently a result of iatrogenic injuries incurred during septal surgery. Chronic inflammatory diseases, such as syphilis [2], Wegener's granulomatosis [3], tuberculosis [4] and malignancy [5] are also known to cause nasal septal perforation. However, until now, very few cases of congenital defect of the vomer bone have been described in the literature. We present a case of a 13-year-old boy whose vomeral defect was incidentally diagnosed on nasal endoscopy during work-up for chronic sinusitis.
Case report
A 13-year-old boy was admitted to our department with a 3 months’ history of nasal obstruction and rhinorrhea. Diagnostic nasal endoscopy revealed a polypoid mass in the right nasal cavity, mild hypertrophy of adenoid tissue and a defect in the posteroinferior portion of the nasal septum. The margins of the defect were smooth and lined by normal nasal mucosa. Besides mild edema, the nasal mucosa was smooth, without any evidence of crusting. Computed tomography revealed partial absence of the vomeral bone, and soft tissue densities in the right nasal cavity and both maxillary sinuses (Fig. 1A and B).
Fig. 1.
(A) Axial computed tomography image showing a shortened nasal septum due to the vomer defect (arrow). (B) Coronal computed tomography image shows the nasal septum does not reach the nasal floor due to the vomer defect (arrow).
No other anomalies were observed in the craniofacial region. Routine blood examination, including full blood count, ESR and serologic tests for syphilis was normal. Urine analysis and chest X-ray were also normal. The patient had no history of maxillofacial trauma, drug abuse and had not undergone cautery for epistaxis or surgery of the nose previously.
Endoscopic sinus surgery for chronic sinusitis with nasal polyp was performed. An ovoid defect in posteroinferior nasal septum was confirmed, and the contralateral nasal cavity could clearly be observed through the defect (Fig. 2). The surgery was uneventful, and the patient was discharged with instructions for frequent nasal irrigation. The patient remains free of symptoms 3 months after surgery.
Fig. 2.
Endoscopic view of the vomer defect through the left nasal cavity. Mild hypertrophy of the adenoid is seen, and the posterior end of the right inferior turbinate is visible through the defect. A, adenoid; LT, left inferior turbinate; RT, right inferior turbinate.
Discussion
There are many causes of septal perforations, such as external trauma, nasal surgery, inhalation of illicit drugs, such as cocaine and snuff, occupational inhalation of chemical irritants, such as hexavalent chrome, arsenic and alkaline dusts [2], chronic inflammatory diseases [2], [3], [4] and neoplasms [5]. However, there have been very few reports concerning septal perforations of congenital causes. We believe that the septal defect in the present case is a congenital defect of the vomer bone, on the basis of an absence of past medical history that may have caused a septal perforation, and the absence of laboratory and physical examination findings suggestive of systemic chronic inflammatory causes of septal perforation.
The vomer is a bony structure forming the postero-inferior part of the nasal septum. Sandikcioglu et al. [6] described three steps of vomeral bone development during the prenatal stage. The earliest appearance of the vomeral bone in the human fetus is at the 8th week of gestation, at which time it appears bilaterally at the posteroinferior end of the cartilaginous nasal septum. These paired vomeral bones fuse to each other in the midline caudal to the nasal septum to form a U-shaped bone in the coronal plane at the 17th gestational week. The base of the U-shaped bony structure is altered by apposition in the median plane during development. The vomeral bone thus appears as a Y-shaped bony structure in the coronal plane.
It is believed that congenital vomer defects result from abnormalities in these developmental stages of the vomer. Mohri and Amatsu [7] proposed two theories to explain this developmental anomaly. The “immature ossification center theory” suggests that the presence of an incomplete or immature ossification center that could lead to incomplete development and/or partial absorption of the vomer later. The “incomplete downward growth theory” suggests that posterior extension and downward growth of the primary nasal septum may be stunted, so that the caudal part of the septum cannot reach the palate when the bilateral palatal shelves fuse completely (Table 1).
Table 1. Reported cases of congenital vomer bone defect
| Case no. | Age | Sex | Associated disease | Author (year) |
|---|---|---|---|---|
| 1 | 44 | F | Chronic otitis media | Mohri and Amatsu [7] |
| 2 | 55 | M | Laryngeal polyp | Mohri and Amatsu [7] |
| 3 | 61 | M | Acute otitis media | Mohri and Amatsu [7] |
| 4 | 4 | M | Otitis media with effusion | Mohri and Amatsu [7] |
| 5 | 39 | M | Pituitary adenoma | Mohri and Amatsu [7] |
| 6 | 24 | F | Cholesteatoma | Mohri and Amatsu [7] |
| 7 | 16 | M | Thalassemia | Doğru [10] |
| 8 | 43 | F | Thalassemia, sensorineural hearing loss | Doğru [10] |
| 9 | 19 | M | Otitis media with effusion | Yilmaz and Altuntas [9] |
| 10 | 13 | M | Chronic sinusitis with nasal polyp | Current study |
Patients with nasoseptal defects usually have intranasal crusting, whistling noise during forced inspiration, difficulty in breathing and recurrent epistaxis [8]. Anterior septal perforations are likely to be symptomatic, but perforations that are located posteriorly within the nose where there is good humidification, may be asymptomatic. Such asymptomatic perforations with well-healed edges rarely require treatment, and often just keeping the nose moist is enough [2]. Our patient did not exhibit symptoms and signs associated with nasal septal perforation. Also, the defect was located in the posterior portion of the nasal septum, and the edges of the defect were lined with normal nasal mucosa. Therefore, we believe that periodic observation and conservative management should be adequate for managing this patient's septal defect during follow-up.
It has been suggested that turbulent airflow and compensatory adenoid hypertrophy created by the septal perforation in the nasopharyngeal region may predispose these patients to ear disease [7], [9]. Doğru et al. [10] reported two thalassemia patients with a congenital vomer defects. Although, it is too early to infer any causal relationships because so few cases have been reported, it may be beneficial to check for signs of otitis media with effusion periodically in these patients.
Because a vomeral defect is located deep in the nasal cavity, its presence is prone to be overlooked unless the physician inspects carefully. A more diligent observation of the posteroinferior portion of the nasal septum during diagnostic nasal endoscopy may lead to the discovery of additional patients with this type of septal defect. Investigation for associated diseases will result in a better understanding of the clinical implications of this rare anomaly.
References
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PII: S1871-4048(06)00095-5
doi:10.1016/j.pedex.2006.11.001
© 2006 Elsevier Ireland Ltd. All rights reserved.
Volume 2, Issue 1 , Pages 17-19, March 2007
