Proximity

• Molars, the flat teeth in the rear of the mouth, reside only inches away from the ear and its complex inner workings.
  
  

Nerve Connection

• Because molars share a very tight space with the ear, the two parts also share some vital connections. The mandibular nerve that delivers blood to molars also branches out to serve the ears.
  
  

Bacteria

• The location of molars in the rear-most portions of the mouth make them difficult to clean with traditional toothbrushes. As a result, bacteria tend to grow on and around the molars.
  
  

Bacteria Travel Along the Nerve

• Left unchecked, bacteria on molars can erode the tooth and cause decay. As the bacteria enters the body and causes a toothache, the pain and infection can travel to the ear. According to Tackling-Toothache.com, this spread of infection is known as "referred pain."
  
  

Diagnosis is Difficult

• Because of the close proximity and shared connection, medical professionals may have a hard time distinguishing between tooth pain and ear infections. Some ear infections may even arise from past dental work or molar extractions.