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Tooth Eruption. Tooth eruption is defined as. “ The movement of a tooth from its site of development within the alveolar process to its functional position in oral cavity,” Massier and Schour, 1941. Active Eruption. Active Eruption & Passive Eruption. Passive Eruption.
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Tooth eruption is defined as “ The movement of a tooth from its site of development within the alveolar process to its functional position in oral cavity,” Massier and Schour, 1941
Active Eruption Active Eruption & Passive Eruption Passive Eruption
Stage of tooth eruption • Pre-eruptive • Intraosseous movement • Eruptive mucosal penetration preocclusal eruption • Post-eruptive
Pre-eruptive stage • Deciduous teeth • Permanent teeth
Eruptive stage Mechanism of eruption
Post-eruptive stage 1. accommodation for growth 2. compensate for occlusal & interproximal wear (mesial drift) 3. supraeruption
ฟันสึก attrition abrasion erosion
Factors consideration in tooth eruption • development of periodontium, root, pulp, alveolar bone • speed of eruption • events during eruption • eruptive pathway: gubernacular canal • 3D movement • inheritable position
Development of Dental Follicle • cementoblasts • periodontal ligament • alveolar bone
Gubernacular canal Gubernacular cord Eruptive Pathway
FORCES of Tooth Eruption • Root Formation • Pressure( Pulp and Hydrostatic ) • Periodontal Ligament • Bone Remodeling and Dental Follicle
Root growth • relation of root growth and eruptive movement:Carlson (1944) • remove HERS • supraeruption • rootless tooth :Gowgiel 1961, 1967 CONTRA
Pulp growth • Antimitotic drugs inhibit mitotic activity of pulp cell :Sicher (1962)Ness & Smale (1959) • Vitamin D deficiency & overdose: Bryer
Hydrostatic pressure • King & Bryer -> sympathetectomy • Main (1961) -> Hypotensive drugs • Hassel & McMinn (1972) -> measure fluid pressure
Periodontal Ligament • Berkovitz & Thomas (1969) -> root resection • Michaeli et al (1982) -> degenerate PDL • Ness (1967) -> PLF • Bellows et al (1983) -> PLF
dental follicle • Control resorption and formation of bone around tooth germ: Cahill & Mark 1974,1980,1983,1987 • no dental follicle, no eruption • PDL , alveolar bone and cementum are derivative of Dental Follicle
Bone remodeling • Apposition & resorption of bone • Vit A and D def. Bone growth • Metal and Acrylic replica:Marks & Cahill (1984)
Molecular biology of Bone Remodeling • Influx of monocytes at the onset of eruption • appearance of osteoclasts • signaling molecules
signaling molecules • CSF-1 • EGF • IL-1 • TGF alpha • TGF beta-1
Problem ????? • In vitro / in vivo • nature of experimental animal ……extrapolation • experimental design…isolate single system
Conclusion of FORCES of Tooth Eruption Multifactorial Multifactorial (However, “Dental Follicle” Activity & Bone Remodeling have the Highest Potential)
Clinical Application 1. Timing of Eruption 2. Unerupted Tooth (Embedded) 3. Tooth Impaction 4. Position of newly Erupted Successors 5. Dental Treatment Consideration on Newly Erupted Tooth 6. Denture and Supra-Erupted Tooth
Exfoliation or Shedding ( Of Deciduous Teeth )
Mono-Phyodontism Di-Phyodontism Poly-Phyodontism
Patternof Shedding • Resorption of roots • anterior/posterior • Shedding of crown
Cause of shedding • Pressure from permanent teeth • loss of bone…weakening of supporter • trauma and inflammation…occlusal stress, caries .. Etc.
Histology of Sheding - Gubernacular Canal - Osteoclasts - Odontoclasts - PerioDontal Ligament
Clinical Application • Remnants of Deciduous Teeth • Retained Deciduous Teeth • Submerged Deciduous Teeth