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Oral anatomy, physio
Vet Dentistry
| Question | Answer |
|---|---|
| What are the 3 basic types of tooth development? | Monophyodont Polyphyodont Diphyodont |
| what is monophyodont? which animals have this type of dentition? | Only one set of teeth erupts and remain in fxn throughout life Dolphins, rodents |
| What is polyphyodont? which animals have this type of dentition? | Many sets of teeth are continually replaced sharks, crocodiles |
| What is diphyodont? which animals have this type of dentition? | Two sets of teeth erupt: primary/deciduous and secondary/permanent domestic animals and humans |
| What are the 3 common types of vertebrate tooth anchorage? | Thecodont Acrodont Pleurodont |
| What is GOMPHOSIS? | a type of fibrous joint in which a conical object is inserted into a socket and held in place Seen in Thecodonts |
| How are acrodont teeth attached? | Ankylosed directly into bone, no true root structure or socket |
| How are pleurodont teeth situated? | grow from pockets inside the jaw (lizards, snakes) |
| What are the basic crown types? | Brachyodont (shorter crown:root ratio) Hypsodont (continually erupting reserve crown) |
| What are 2 types of hypsodont teeth? | Radicular: true roots eventually close their apices and cease growth Aradicular: absence of true roots, crown is continually formed to erupt throughout life |
| What types of cusps do secodont teeth have? | Those with cusps arranged to provide cutting/shearing action: carnassial teeth in carnivores |
| What types of cusps do bunodont teeth have? | Low, rounded cusps arranged on a flat occlusal surface for grinding: molars in carnivores and primates |
| What types of cusps do lophodont teeth have? | cheek teeth cusps connect to form ridges: rhino, elephant |
| What type of cusps do selenodont teeth have? | cheek teeth cusps connect to form a crescentic outline w/ a quarter moon ridge pattern |
| What type of cusps do bunolophodont teeth have? | cheek teeth have both rounded cusps and transverse ridges on occlusal surface |
| What type of cusps do bunoselenodont teeth have? | Cheek teeth have rounded cusps and crescentic ridges on the occlusal surface of the crown |
| What are 2 types of Jaw Occlusal Overlay? | Isognathous Anisognathous |
| What type of teeth do dogs and cats have? | diphyodont development of heterodont type teeth in anisognathic jaws anchored as tehcodonts, with brachyodont crowns of secodont premolars and bunodont molars |
| What structure separates the stomodeum and foregut early in embryonic development? | buccopharyngeal membrane |
| What are the anatomic boundaries of the oropharynx? | Tonsils laterally, base of tongue ventrally this is the level of the buccopharyngeal membrane during fetal development |
| When does initial development of dental structures occur? | During embryonic formation: ~ 25th day the embryonic oral epithelium begins to thicken |
| What forms the upper and lower jaws? | Thickening oral epithelium: dental lamina-->U-shaped structures of the jaws |
| Where does the enamel organ arise? | from a series of invaginations of the dental lamina |
| Which parts of the oral cavity derive from embryonic ectoderm? | oral epithelium, dental lamina, enamel organ |
| Which parts of the oral cavity derive from embryonic mesoderm? | dental papilla and sac |
| What are the developmental stages of the enamell organ? | Bud, cap, bell |
| What are the 4 components of the enamel organ? | IEE: inner enamel epithelium OEE: outer enamel epithelium stellate reticulum stratum intermedium |
| What do the mesodermal/mesenchymal cells adjacent to the IEE become? | Dental papilla-->dentinal and pulpal tissues |
| What structures does the dental sac give rise to? | cementum, PDL, some alveolar bone |
| What is the function of the OEE of the enamel organ? | protective layer for the entire organ |
| What is the function of the Stellate reticulum of the enamel organ? | Works as a cushion for protection of the IEE and allows vascular fluid to percolate between cells and reach the stratum intermedium |
| What is the function of the stratum intermedium for the enamel organ? | converts the vascular fluids to usable nourishment flr the IEE. |
| What is the function of the IEE of the enamel organ? | responsible for actual enamel formation |
| What are the lingual extensions from dental lamina buds which form the primary dentition? | successional lamina. they go through the bud, cap, and bell stages to eventually for succcessional permanent dentition |
| Which structure forms the primary palate? (premaxilla, incisal bone) | Medial nasal process |
| What structures form the secondary palate? | left and right maxillary processes |
| Where do PRE-AMELOBLASTS come from? | IEE cells evolve into taller cells during the bell stage to become preameloblasts |
| Where do ODONTOBLASTS come from? | peripheral cells of the dental papilla bordering the preameloblasts transform into cuboidal cells and beging to migrate toward the center of the dental papilla, away from the preameloblasts |
| Where do AMELOBLASTS come from? | preameloblasts undergo a polarity shift such that the nuclei move from the center of the cells toward the stratum intermedium |
| What do AMELOBLASTS do? | Secrete enamel matrix: mucopolysaccharide ground substance and organic fiber |
| What do ODONTOBLASTS do? | leave behind a secreted dentinal matrix of mucopolysaccharide ground substance and collagen fibers as they migrate toward the center of the papilla |
| What is the inorganic composition of enamel? | 96% hydroxyapetite crystals, magnesium, other ions |
| What is the organic composition of enamel? | 4% water, collagen |
| During what developmental stage is the enamel matrix laid down? | Late bell stage |
| What happens during the minerailzation stage of calcification of the enamel rods? | CRYSTAL IS LAID DOWN WITHIN THE RODS |
| What happens during the maturation stage of calcification? | crystals grow in size, becoming tightly packed together within the enamel rods |
| Once the ameloblasts migrate to reach the OEE, what happens? | stratum intermedium and stellate reticulum are lost ameloblasts lay down Nasmyth's membrane |
| What is Nasmyth's membrane? | Primary enamel cuticle: a protective layer on top of enamel |
| What is the origin of the reduced enamel epithelium? | Fusion of the ameloblasts with the OEE after Nasmyth's membrane is formed |
| What is the function of the reduced enamel epithelium? | produces an adhesive-like secretion: secondary enamel cuticle AKA epithelial attachment |
| What is the definition of HYPOPLASTIC ENAMEL? | Normal density of calcification, but enamel is thinner than normal |
| What is the definition of ENAMEL HYPOCALCIFICATION? | poorly mineralized areas of the enamel show as white, yellow, or brown spots |
| What is the mineral/inorganic composition of dentin? | 70% hydroxyapatite crystals |
| What is the organic composition of dentin? | 30% collagen fibers, mucopolysaccharide substance, water |
| What is another name for odontoblastic processes within dentinal tubules? | Tomes fibers |
| What is the definition of PRIMARY DENTIN? | Forms before eruption of the tooth |
| What is the definition of SECONDARY DENTIN? | Forms after eruption of the tooth |
| What is TERTIARY DENTIN? What stimulates its formation? | REPARATIVE dentin: trauma to dontoblasts (thermal, mechanical, occlusal, or chemical) |
| What is the average density of odontoblastic processes in primary and secondary dentin? | 30,000 - 40,000 odontoblastic processes per square mm |
| Where is interglobular dentin located? | next to DEJ: dentino-enamel jxn hypocalcified during formation |
| What are Granular layers of TOMES DENTIN? | Same as interglobulra, except located next to CDJ: cemento-dentinal jxn |
| What is DEAD TRACT DENTIN? | Tubules are empty, don't contain odontoblastic processes |
| What tissues constitute the PULP? | blood vessels lymph vessels nerves fibroblasts collagen fibers undifferentiated reserve mesenchymal cells other connective tissue cells odontoblasts |
| Which cell layers of the enamel organ form hertwig's epithelial root sheath? | OEE and IEE at the cervical loop junction |
| What is the origin of EPITHELIAL RESTS OF MALASSEZ? | Hertwig's Epithelial root sheath cells that move away from dentin but fail to dissolve become entrapped in the PDL |
| What is the EPITHELIAL DIAPHRAGM? | The portion of the root sheath that angles back toward the center of the forming root, determines the number of roots a tooth develops |
| What are ENAMEL PEARLS? | Enamel secreted onto the root by epithelial root sheath cells that converted into ameloblasts after they failed to dissolve and remained in contact with dentin |
| What is the inorganic and organic composition of CEMENTUM in man? in horses? | MAN: 45-50% INorganic, 50-55% organic HORSES: 66% INorganic, 34% organic |
| What is acellular cementum? Where is it located? | Cementum which does not contain cells entrapped within the calcified matrix. Cervial 1/2 to 2/3 of the root |
| What is the cellular cementum? Where is it located? | cementum that contains cementocytes trapped within the calcified matrix Apical 1/3 of the root |
| What are SHARPEY'S FIBERS? | PDL ligament fibers embedded in cementum and/or alveolar bone |
| What are the 3 bone layers of the alveolus? | cribiform plate/lamina dura cortical plate cancellous/trabecular bone |
| What is bundle bone | additional bone laid down on the cribriform plate as a result of remodeling due to occlusal stresses |
| What type of nerve fibers does the pulp contain? | pain only |
| What types of nerve fibers does the PDL contain? | pain, pressure, heat, and cold |
| How many deciduous teeth do dogs have? | 28 |
| How many permanent teeth do dogs have? | 42 |
| How many deciduous teeth do cats have? | 26 |
| How many permanent teeth do cats have? | 30 |
| What is a line angle? How many exist for each tooth? | dividing lines formed between 2 surface areas of a tooth. 8 per tooth |
| What is a point angle? How many exist for each tooth? | junctures of three line angles. 4 coronal point angles for each tooth |
| What is a contact area? What are 2 different kinds? | an area where adjacent or opposing teeth make contact. occlusal or proximal |
| What is the name of the cavern within the tooth where the pulp resides? | Pulp cavity |
| What is the portion of the pulp cavity within the crown called? | Pulp chamber |
| What is the portion of the pulp cavity within the root called? | Root canal |
| What is the largest, most powerful muscle of masticatioin? | temporalis (depends on the species?...Masseter in horses?) |
| What are the muscles of mastication? | temporalis masseter lateral and medial pterygoid |
| What nerve innervates the muscles that close the jaws? | Trigeminal, CN V |
| What muscle opens the jaw? | Digastricus |
| What nerve innervates the digastric muscle? | rostral belly: trigeminal n. caudal belly: facial n. |
| What is the intrinsic muscle of the tongue? | m. lingualis proprius |
| What nerve innervates the muscles of the tongue? | Hypoglossal nerve (CN XII) |
| What are the extrnisic muscles of the tongue? | Styloglossus hypoglossus genioglossus |
| What other nerves innervate the tongue for touch, pain, heat, taste, and gland fxn? | lingual (CN V) chorda tympani (CN VII) glossopharyngeal (CN IX) |
| What are the 3 kinds of gustatory papillae of the tongue which contain taste buds? | fungiform vallage foliate |
| What are the mechanical papillae of the tongue that do not contain taste buds | filiform conical marginal |
| What is the primary blood supply to the tongue | lingual arteries |
| What inorganic and organic substances compose saliva? | electrolytes (calcium, bicarbonate, chloride, sodium , potassium) proteins (immunoglobulins) hormones minerals vitamins enzymes (amylase--only in some species) |
| What are the antimicrobial qualities of saliva? | pH (generally alkaline) mucous lysosomes immunoglobulins fluoride |
| Which species has the most alkaline saliva? | cows |
| Which domestic species have a zygomatic salivary gland | dogs, cats |
| Which species has molar salivary glands? | cats |
| What are RETE PEGS? | Epithelial extentions that insert into (interdigitate with) the underlying connective tissue |
| Where are Rete Pegs most developed and densly arranged? | In keratinized and parakaratinized masticatory mucosa |
| What are the connective tissue extensions that interdigitate with rete pegs called? | dermal papilla |
| What domestic animal has the most complete dentition? JVD Spring 2013 | Pig (44 teeth) |
| Where does the NL duct empty into the nasal cavity? JVD Summer 2013 | lateral wall of the vestibule |
| Where is the lacrimal foramen located in cats? JVD Summer 2013 | just ventral to the infraorbital foramen. The (at the level of the maxillary 3rd premolar teeth) |
| In domestic cats, whre is the NL duct always located in relation to the maxillary canine tooth? | dorsal or dorsomedial to the maxillary canine tooth root separated only by the thin alveolar bone |
| What are 4 possible etiologies of acquired NL duct obstruction? JVD Summer 2013 | infections, neoplastic, traumatic, mechanical obstrxn |
| In the dog mouth, where are periodontal tissues generally thickest? JVD Fall 2013 | canines, maxillary PM4, mandibular M1 |
| in the dog, where are periodontal tissues generally thinnest? JVD Fall 2013 | incisor and first premolars |
| What constituents of saliva are present in significantly higher proportions than they are in plasma? JVD Winter 2010 | potassium and bicarbonate |
| What ions are present in significantly lower concentrations in saliva compared to plasma? JVD Winter 2010 | sodium and chloride |
| How can excessive salivation affect total body potassium levels? JVD Winter 2010 | can deplete total body potassium levels |
| How does aldosterone affect ion concentrations in saliva? JVD Winter 2010 | increases potassium and decreases sodium an chloride even further |
| Which portion of the nervous system regulates salivation? JVD Winter 2010 | autonomic nervous system (parasympathetic and sympathetic) |
| What is the average pH of saliva in humans? dog/cat? ruminants? JVD Winter 2010 | 6.6 (human), 7.5 (dog/cat), 8.2 (ruminant) |
| What type of saliva do parotid glands produce? JVD Winter 2010 | serous type |
| What type of saliva do subligual glands predominantly produce? JVD Winter 2010 | mucous |
| What type of acini do the mandibular salivary glands contain? JVD Winter 2010 | both serous and mucous = "mixed" |
| Which domestic animals have zygomatic salivary glands? JVD Winter 2010 | dogs and cats only |
| What salivary glands do only cats have? JVD Winter 2010 | molar glands (no other animal has them) |
| Why is saliva so important in ruminants (produced in large volumes)? JVD Winter 2010 | buffers acids from forestomach (high bicarb content), provides nutrients for microbes in the rumen (nitrogen, phosphorus, sodium), provides liquid environment for fermentation in rumen, antifoaming agent in the rumen |
| What digestive enzyme is present in the saliva of omnivores (human, pig, rat)? JVD Winter 2010 | amylase (converts starch to maltose) |