WISDOM TOOTH (3RD MOLAR)

The last tooth in the series of teeth in the upper and lower jaws is called wisdom tooth. They are four in number, one on each side of the upper and lower jaws.

This tooth is the last of all the teeth to erupt into the mouth between the age of 17 and 25years, beyond this age it is not likely to erupt into the mouth hence the term impaction.

Impaction can be due to soft tissue (gingivae) or hard tissue (jaw bone).

While some people have their wisdom tooth completely erupted into the oral cavity but covered with gingivae(gum),some other people have theirs partially erupted into the mouth with impaction against the jaw bone while others  have theirs completely buried within  the jaw bone.

Causes of impacted wisdom tooth

1. When the teeth are large, they occupy more space than required; this prevents the last tooth from erupting fully as there is limited available space.

2. When the teeth are of normal size but the jaw size is small.

3. Tooth ankylosis

4. Cyst/Tumour

Effects of impacted wisdom tooth

When partially erupted they cause recurrent infection due to communication between the oral cavity (filled with microbes and food debris) and the jaw bone. The infection is termed pericoronitis.

Pericoronitis:



Impacted wisdom tooth

 

 

 

 

 

 

 

 

Is the inflammation of the gum around the wisdom tooth; commonly seen in adolescents and young adult.

Symptoms

Fever, headache, dysphagia, pain and discomfort

Signs

1. Trismus (limitation in mouth opening)

2. Fetor oris (bad breath)

3. Redness of the gum around the tooth and tenderness

4. Pus discharge

The severity of this lesion depends on the stage at presentation



Radiograph of an impacted wisdom tooth



 

 

Treatment:

Debridement of the area

Operculectomy

Surgical disimpaction

Cyst/Tumour formation:
 

Recurrent pericoronitis over a long period of time may stimulate cyst formation and possible eventual tumour formation. Noguchi, et al.(2013) reported a cystic lesion with impacted wisdom tooth  which turned out to be an ameloblastoma (jaw tumour).

 



Cyst formation around an impacted wisdom tooth



 

 

 

It is advisable to heed your dentist’s advice on the specified treatment for your case in order to avoid complications that may arise from wisdom tooth impaction.

References:

Kazuma Noguchi, Hiromitsu Kishimoto, Koji Yamanegi, Kuniyasu Moridera, Kazuki Takaoka

and Masahiro Urade (2013): Unicystic ameloblastoma metastasizing to multiple cervical

lymph nodes. JSCR 2013.