Deviated Nasal Septum: DNS in ENT

Deviated Nasal Septum or DNS is one the most common disorder of ENT in worldwide population affecting 80% of population at some level. We will discuss more about nasal septum deviation as we proceed. In this blog, we will learn about definition, types, causes, clinical features and treatment of Deviated Nasal Septum DNS ENT.


Nasal Septum Deviation or Deviated Nasal Septum (DNS) is the displacement of nasal septum from its normal anatomical position. This displacement is generally ignored by the patient until it causes nasal obstruction and breathing problems.


The Aetiology of DNS marks 3 important factors:


A hit to nose can cause deviated nasal septum. This hit deviates nasal septum
such as lateral displacement, buckling, twisting, telescoping of nasal fragments, etc. Most of these traumatic injuries are caused during childhood and often ignored. However, since a newborn is obligate nose breather, nasal deviation is attended immediately to treat the following nasal obstruction caused by deviated nasal septum.

Congenital Developmental Disorders

DNS is often associated with developmental disorders like cleft lip, cleft palate. Adenoid hypertrophy resulting in high arched palate, can also cause septum to be deviated. Buckling is caused by palate and base of skull unequal growth.

Hereditary and Racial Factors

Caucasians are more prone than Americans and family pattern is quite often marking.


DNS occurs either in Cartilages /Bone or both as follows :-

C-Shaped deformity
C-shaped deflection of nasal septum occurs as a simple curve along lateral side of central line.
c shaped nasal septum deviation

S-Shaped deformity
This often causes bilateral nasal obstruction and is depicted as :-
s shaped nasal septum deviation

Anterior dislocation
Along a simple straight line, the nasal septum dislocates to one of the nasal chambers.
anterior disclocation nasal septum deviation

A nasal spur is spiked protrusion or shelf like projection. The Spurs often result in Epistaxis, migraine and headaches,
nasal spur nasal septum deviation

Nasal septum may thicken at it’s own position, probably due to haematoma.
thickening nasal septum deviation

Clinical Features

Deviated Nasal Septum (DNS) can causes nasal obstruction, headache, epistaxis, anosmia, sinusitis, external deformity and middle ear infection.

1. Nasal Obstruction

Respiratory currents pass through upper part of nasal cavity, therefore, high septal deviation causes nasal obstruction more than lower ones. This is why epistaxis occurs more frequently with high septal deviation.
Nasal obstruction can be any of the 5 type:

  • Vestubular
  • At nasal valve
  • Attic
  • Turbinal
  • Choanal

Also, high septal deviation causes more marked nasal obstruction than low septal deviation.


It is useful when the obstruction of DNS occurs at nasal valve.

Draw cheek while towards lateral side while breathing slowly and quietly.

If there is relieving of nasal obstruction with improved airway ventilation, then the test is considered positive.

There is abnormal vestibular component of nasal valve.

2. Headache

As mentioned earlier, a nasal spur often causes pressing of lateral side of nose, causing pressure headache.

3. Epistaxis

Apart from nasal spur, deviated nasal septum causes mucosa to be exposed to dry air, therefore, mucosa dries up to form crusts, which when removed, causes intense bleeding.

4. Anosmia

The inspired air may be unable to reach the olfactory sensory region, leading to loss of smell.

5. Sinusitis

Obstruction of sinus ostia by DNS causes sinusitis.

6. External Deformity

These may be associated with DNS

7. Middle ear infection

Since nose is connected to middle ear by eustachian tube, infections of nose often ascend to middle ear.


DNS on minor extent or without any symptoms doesn’t usually required treatment. However, management is appropriate to prevent further extension.

Treatment is necessary when Deviated nasal septum produces nasal obstruction or symptoms as listed earlier. SMR (Submucous Resection) or Septoplasty are two surgical operations in DNS which are performed below age of 17 years so as to avoid interfering with the growth of nasal skeleton.


SMR or SubMucous Resection operation is done under anaesthesia. Mucoperichondrial and Mucoperiosteal flap are elevated following incision at side of septum. This is followed by removing the deflected parts of septum and once finished, repositioning these flaps back.


Septoplasty has replaced SMR nowadays. This is a conservative surgery to retain most of septal framework. Rather than removing all the deflected part of nasal septum, only the most deviated parts are removed. Remaining less affected parts are corrected and repositioned by plastic means. Moreover, it can be performed in children (below age of 17 years) given there is marked nasal obstruction.

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