Tooth eruption

• Tooth Eruption (Part 1) is the pre-eruptive phase where the tooth is still in the jawbone.
• The Eruptive Phase involves the formation of the Gubernacular Canal and Cord.
• The Anatomic Crown is different from the Clinical Crown.
• Changes to the tooth occur during the Post-eruptive Phase.
• Types of Post-eruptive Movement include Supra Eruption and Mesial or Approximal Drift After Orthodontic Treatment.
• Forces That Bring About Mesial Drifting of Teeth include the Initiation of Root Formation and Supra Eruption.
• Actual axial movement of the tooth into the oral cavity until it occludes with its antagonist is an event of the Eruptive Phase.
• Key cells in root formation are Hertwig’s Epithelial Root Sheath (HERS), which appear to be involved in the initiation of the process in root elongation and in stimulating both cementogenesis and root dentinogenesis.
• Hertwig’s Epithelial Root Sheath (HERS) is an investment of epithelial cells around the unerupted tooth and inside of the dental follicle, consisting of outer and inner enamel epithelium only.
• For the Hertwig’s Epithelial Root Sheath (HERS) to do its job, it must always stay in the root apex to allow root elongation.
• By remaining in the root apex, Hertwig’s Epithelial Root Sheath (HERS) cells are in contact with preodontoblasts that allow progressive root elongation.
• Compensation for occlusal wear is a variant or form of compensation for occlusal wear.
• Lack of contact will also lead to post-eruptive tooth movement.
• As you get older, your teeth will be subjected to occlusal wear.
• One of the other changes that happens as we age is also wearing away of the interproximal contact of the teeth – the mesial and distal surfaces.
• Mesial or Approximal Drift is the lateral bodily movement of the teeth on both sides of the oral cavity towards the anterior part.
• Mesial or Approximal Drift is an important consideration in orthodontic movement because there is a natural tendency of the teeth to migrate or move mesially when there is no contact between them or when contact is lost due to cavities, dental caries, fractures, physiological wearing away of interproximal surfaces.
• The upper left picture shows a case of a young set of permanent teeth, wherein premolars were extracted.
• The three factors that bring about mesial drifting of teeth are the anterior component of occlusal force, contraction of transseptal ligament, and soft tissue pressure.
• The Anterior Component of Occlusal Force (ACF) is the tendency of occlusal forces to be dissipated axially toward the anterior part of the oral cavity through the proximal tooth contact points.
• The Anterior Component of Occlusal Force is believed to arise as a result of mesial inclination tendency of permanent teeth.
• The summation of intercuspal planes produces a forward directed force.
• Supracrestal Fiberotomy is a surgical procedure to prevent relapse of orthodontic treatment that entails releasing the connective tissue supracrestal fibers that are attached to the tooth and bone.
• In occlusal wear compensation, continuous cementum deposition occurs on both sides of the oral cavity towards the anterior part.
• After the tooth makes its way to the connective tissue, the REE of the tooth will now fuse with the OE.
• REE and OE form a pathway called Hertwig’s Epithelial Root Sheath (HERS).
• Gubernacular cord is located within the scaffold which is also known as the gubernacular canal.
• Differentiation occurs in the REE, not OE.
• Post-eruptive phase includes the initiation of root formation, when the tooth enters the connective tissue, and when the reduced enamel epithelium fuses with the oral epithelium.
• Degeneration of the Collagen Fiber and Decrease in blood vessels and nerves occur during the post-eruptive phase.
• Hertwig’s Epithelial Root Sheath (HERS) is the anterior component of occlusal force, contraction of transseptal ligament, and soft tissue pressure.
• Supracrestal Fiberotomy is performed around the apex of the tooth.
• Mesial or Approximal Drift is a type of lateral bodily movement of the teeth on both sides of the oral cavity towards the anterior part.
• Gubernacular Canal is located within the scaffold which is also known as the gubernacular canal.
• As long as the Hertwig’s Epithelial Root Sheath (HERS) is in the epithelial diaphragm, you’ll have the elongation of the root.
• Post-eruptive movements refer to the movements that happen when you have a full set of permanent teeth except the third molars.
• Post-eruptive movements can occur between 12 to 21 years old.
• Post-eruptive movements may play a role in adulthood, after your 21st birthday, if the occlusion deteriorates.
• Post-eruptive movements are divided into three categories: Accommodation for Jaw Growth, Completed at 20 years old, and Compensation for Occlusal Wear.
• Accommodation for Jaw Growth movements are to accommodate the growing jaws and occur between ages 14 and 18, the most active age because it is the juvenile growth peak.