Types of Malocclusion

Malocclusion is a misalignment or incorrect relation between the teeth of the two dental arches when they approach each other as the jaws close.

Crowding

• Cause: Discrepancy between arch length and teeth size.
• Clinical Presentation: Teeth overlap and are displaced in different directions.
• Classification:
  • Mild: Up to 3 mm.
  • Moderate: 3 to 5 mm.
  • Severe: More than 5 mm.
• Treatment:
  • Mild: Expansion and proclination.
  • Moderate to Severe: Use of various strategies and auxiliary techniques.

Spacing

• Definition: Presence of interdental spaces and lack of interproximal contacts.
• Causes: Tooth size discrepancy, missing teeth, parafunctional habits.
• Treatment:
  • Mild: Corrected with aligners.
  • Moderate: Corrected with retraction.
  • Severe: Combination of techniques including clear aligners and auxiliaries.
• Retention: Crucial after treatment to prevent relapse.

Deep Bite

• Definition: Increased vertical overlap of upper incisors over lower incisors.
• Implications: Functional issues for the patient.
• Treatment: Correctable with aligners if not too severe.

Open Bite

• Definition: Anterior or posterior teeth do not contact opposing arch.
• Types:
  • Anterior: Front teeth not in contact.
  • Posterior: Back teeth not in contact.
• Causes: Can be dental or skeletal; related to habits, ankylosed teeth.
• Diagnosis: Requires evaluation of soft tissue profile, maxillary arch form, mandibular angle.
• Treatment:
  • Use of clear aligners and possible auxiliary techniques.
  • Monitor for posterior open bite during treatment.

Crossbite

• Definition: Inverted relationship where upper teeth are palatally displaced relative to lower teeth.
• Types:
  • Dental: Related to tooth displacement.
  • Skeletal: Related to narrow maxillary arch.
• Diagnosis: Requires clinical exam and X-rays to differentiate between dental and skeletal crossbite.
• Treatment:
  • Dental: Corrected with aligners.
  • Skeletal: May require expansion with additional appliances.

Sources and References

1. Gale Encyclopedia of Medicine, Mar 2021
2. Mosby's Medical Dictionary, 9th Edition, 2009
3. T.T. Weir, 2017