Nuggets para national dental board part i
DENTAL ANATOMY AND OCCLUSION ***Look to the book for eruption sequence ***Make a chart w/ # of canals by tooth – start w/ 77 Q 9779a Q44 – confirm w/ correct eruption sequence, 85 – review Pullinger 80 Q90 – Bennett shift TOOTH COMPOSITION & DEVELOPMENT REVIEW Basically everything is from Ectomesenchyme except for Enamel, which is from Ectoderm A quick review of Odontogenesis Initiation Induction – interaction between ectomesenchyme and epithelium 6th week Formation of dental lamina Bud Stage Proliferation –both dental lamina and underlying ectomesenchyme 8th week Dental lamina into 10 buds per arch Shape of tooth is evident Enamel organ starts to form Tooth buds of the Maxilla appear 1st! Cap Stage Proliferation and Differentiation Morphodifferntiation – change into other shapes Histodifferentiation – branch into different tissues 9-10th week ***NOW tooth germ is complete Bell Stage Differentiation of Odontoblasts For the whom the BELL TOMES Differentiation to its furthest extent resulting in 4 different cell types in the bell-shaped enamel organ (makes enamel and Hertwig‘s root sheath) OEE – cuboidal IEE – columnar (Think I looks like a column) Stellate reticulum – network of star-shaped cells
1
Stratum intermedium – flat to cuboidal Dentalpapilla (makes dentin and dental pulp) differentiate into 2 layers Outer cells Central cells Dental sac (makes Cementum, PDL, and alveolar bone proper) increases in collagen fibers 11-12 weeks Remember enamel organ makes Enamel Appositional Stage Cells that were differentiated into specific tissue-forming cells begin to deposit the specific dental tissues (i.e. enamel, dentin, cementumand pulp) Maturation Stage Mineralization begins at the DEJ and continues until total development accomplished, taking approximately 2 yrs to complete Enamel Ectodermal Origin 4 Layers of Enamel Organ Outer enamel epithelium Outer cellular layer Inner enamel epithelium (IEE) Innermost layer Cells will become ameloblasts Essential for the initiation of dentin formation *NOTE: In a developing tooth, the junction of the dental papilla and the IEE becomes the DEJ Stratum Intermedium Think I is next to I Lateral to inner enamel epithelium Essential to enamel formation (nutrients for the ameloblasts of inner enamel epithelium) – during calcification Stellate Reticulum Central core and fills bulk of organ Contains lots of intercellular fluid (mucous type...
Regístrate para leer el documento completo.