Prognathism – Types, Causes and Diagnosis

Prognathism is a condition in which protruding of either of the upper or lower jaws is caused by the structural abnormalities of the face. It is the type of genetic jaw disorder.

Types of prognathism

  • Alveolar prognathism: Alveolar prognathism is a condition in which tooth socket protrudes from the lower jaw. In this type of prognathism, abnormalities are seen around the jaw where teeth are located.
  • Mandibular prognathism: Mandibular prognathism is the condition in which teeth of lower jaw protrudes over teeth of upper jaw leads to extended chin. This condition is also called progenism.
  • Maxillary prognathism: Teeth of the upper jaw overlaps on the teeth of the lower jaw, this condition is called maxillary prognathism. This gives the face an elongated appearance.

Causes of prognathism

  • Family history of protruding jaws
  • Genetic disorders such as down syndrome, basal cell nevus syndrome
  • Growth hormone disorders such as gigantism, acromegaly
  • Excessive growth of mandible or temporomandibular joint disorder causes mandibular prognathism
  • Tongue thrushing and mouth breathing causes mandibular prognathism
  • Thumb sucking or using pacifiers causes maxillary prognathism

Symptoms of prognathism

  • Difficulty in eating, biting or talking
  • Overlapping and protruding of teeth
  • Extended chin, elongated face

Diagnosis of prognathism
Dentist diagnose prognathism by performing some tests that helps the dentist to choose right treatment for prognathism. Diagnosis tests evaluates the type of prognathism that include:

  • Physical examination: Dentist physically examines the temporomandibular joint, upper and lower jaw and observe the movement of jaw and positioning of the teeth. Checks biting and talking ability.
  • Skull x-ray: Skull x-rays are taken to diagnose prognathism. Skull x-rays gives the pictures of temporomandibular joint and upper and lower jaws. It helps to diagnose the abnormalities in the teeth of upper and lower jaw.
  • Dental x-rays: Panoramic dental x-rays are taken which gives the complete pictures of the oral cavity. This helps the dentist to diagnose the abnormality or overlapping of teeth.
  • Bite impressions: Bite impressions are taken for the construction of the molds. Plastic molds are prepared for your teeth and applied to your teeth. This molds helps to repositioning of upper and lower jaws in their original position.