oral histo and embryo
Terms
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- von Korff's fibers
- characteristic of mantle dentin, fan-shaped, thich coarse bundles of collagen fibers in between odontoblasts
- circumpulpal dentin
- smaller fibrils of collagen, typical of the bulk of dentin, present in mantle dentin
- terminal branches of odontoblasts
- numerous, small, located near the DEJ
- collateral branches of odontoblasts
- larger and leave the odontoblstic process at a right angle almost anywhere along its length
- interglobular dentin
- hypocalcified region
- globular dentin
- normally calcified region
- aprismatic enamel matrix
- first enamel layer
- tome's process
- as ameloblsts retreat, short blunt process, and when the cell retreats, it retreats its process as well, leaving a depression in the enamel matrix, rod space
- reduced enamel epi
- protects the newly formed enamel but participates in the formation of early dentogingival jxn
- primary enamel cuticle
- acellular noncalcified produced by postameloblasts
- as hertwig's epithelial root sheath elongates,
- its apical rim is folded in a medial direction. this folded rim = epithelial diaphragm
- epi diaphragm
- stabilized at the region where it develops so that it cannot move in a coronal or in an apical direction
- as root is being formed,
- the entire developing tooth is moving surfaceward toward the oral cavity
- hyaline layer of Hopewell-Smith
- internal layer of Hertwig's epithelial root sheath elaborates a thin, enameloid-like substance on the surface of the newly formed dentin believed to facilitate the adherence of cementum to dentin
- rest cells of Malassez
- partial degeneration pieces of hertwig's epi root sheath
- cementoblasts
- ectomesenchymal cells from dental sac (follicle) pass through rests of Malassez differentiate into cementoblasts, manufacture cementum matrix
- enamel pearls
- in regions where ectomesenchymal cells do not penetrate between the inner layer of hertwig's epi root sheath and the radicular dentin, enamel pearls may develop. these are produced by cells of the epi root sheath which in unknown manner differentiate into functioning ameloblasts
- primary dentin
- dentin formed prior to the completion of root formation
- secondary dentin
- similar to circumpulpal dentin, dentin that is formed subsequent to root completion, but not in response to trauma, slower rate than primary dentin and also unequal fashion, more on roof and floor of the pulp chamber
- tertiary dentin (reparative)
- the more intense the trauma, the more irregular the tertiary dentin
- dead tracts
- if noxious stimulus severe, odontoblasts will die, hollow dentinal tubules, microbial agents access route to pulp, the pulp reacts quickly to such dead tracts by rapidly forming tertiary dentin
- sclerotic dentin
- more in radicular (apical half of the root) dentin, hypercalcified and transparent dentin, occurs subsequent to trauma
- contour lines of Owen
- metabolic disturbances during dev, additional regions of hypocalcifications in dentin, wide arcs of ring perpendicular to the dentinal tubules
- daily imbrication lines of von Ebner
- fine lines indicative of daily deposition of dentin, perpendicular to dentinal tubules
- neonatal line
- exaggerated striae of Retzius, display fewer enamel crystals
- granular layer of Tomes
- in radicular dentin near CDJ, result of tortuous curvatures of the terminal portions of the dentinal tubules
- dentin most sensitive at
- DEJ and pulp
- morphology of enamel rods
- wide head and narrow tail, one ameloblast make head, three make tail
- striae of Retzius
- developmental disturbances in enamel, analogous to the lines of Owen in dentin, numerous rod segments
- perikymata
- at the tooth surface, where striae of Retzius overlap one another as shingles on a roof, they form shallow parallel grooves that encircle the tooth
- DEJ is
- scalloped so that convexity of the enamel fits the concavity of the dentin
- enamel spindle
- terminal ends of the odontoblastic processes that were trapped in enamel during tooth development
- enamel tufts
- at DEJ, look like tufts of grass, hypomineralized groups of enamel rods, ameloblasts fail to resorb much of the enamel matrix
- enamel lamellae
- hypomineralized regions of enamel that extend from DEJ to the enamel surface, thin leaf-shaped regions
- intramembranous bone formation
- relies on a preexisting sheet of loosely arranged collagenous membrane
- immature or woven bone
- newly formed bone whose collagen fibers are irregularly arranged
- endochondral bone formation
- relies on the presence of cartilage model
- periosteal bud
- consists of blood vessels, osteoprogenitor cells, stem cells, and mesenchymal cells
- primary center of ossification
- in endochondral bone formation, diaphysis
- sharpey's fibers
- anchor periosteum to bone
- alveolar bone proper
- the part of the alveolus which immediately surrounds the root of the tooth that is into which fibers of the periodontal ligament are embedded, is compact bone, aka cribriform plate, lamina dura, bundle bone
- supporting alveolar bone
- remainder of the alveolar bone which supports the alveolar bone proper
- alveolar bone proper synonyms
- cribriform plate, lamina dura, bundle bone
- cortical plates of mandible are
- thicker than that of maxilla
- cementum considered part of
- periodontium
- cementum is
- avascular and does not possess a nerve supply
- resting lines
- parallel lines of cementum, successive layers of cementum
- acellular cementum
- primary cementum, coronal 1/2 of root
- cellular cementum
- secondary cementum, house cementoblasts, apical region
- cementicles
- result from calcifications around the rest cells of Malassez, hypercementosis
- mesenchyme
- neural crest
- masticatory mucosa
- hard palate, gingivae, dorsum of tongue
- subepithelial connective tissue subdivided into
- lamina propria and submucosa
- submucosa
- deeper, denser layer
- lamina propria
- looser, superficial layer
- stratum basale (stratum germinativum),
- deepest cell layer of the epidermis of thick skin, in direct contact with the basal lamina, mitiotic divisions,numerous hemidesmosomes, gap jxns, desmosomes
- stratum spinosum
- above stratum basale, numerous short blunt processes (intercellular bridges)= prickle cells, numerous desmosomes, may produce membrane coating granules (lamelated granules, odland bodies) which are released into extracellular spaces and coat the external surfaces of the cell membs to decrease permeability of the epithelium
- merckel cells
- aka clear cells in stratum basale, tactile receptors, mechanoreceptors which react to pressure
- alveolar mucosa
- overlies the cortical plate of the alveolar process, non-kera, vascular even though paillary layer almost absent
- collagen fibers of the gingiva undergo a turnover that is much more rapid than elsewhere in the body except
- PDL
- sulcular epi
- epi that lines the free gingiva in the sulcus, non-kera, no epi ridges
- jxnal epi
- located on enamel surface only, non-kera, epi ridges absent, hemidesmosomes attach jxn epi to tooth surface
- koplik's spots
- measeles, yellow spots on a red surface on the buccal mucosa in the vicinity of max molars
- mumps
- common viral lesion of the parotid gland
- most frequent location of a sialolith
- duct of the submandibular gland
- salt and sweet
- CN VII supplying the fungiform papillae
- bitter and sour
- CN IX innervating the circumvallate and foliate papillae
- bitter
- CN X epiglottis and root of the tongue
- guiding cusps
- noncentric cusps, shearing cusps
- supporting cusps
- centric cusps