|Of what origin is the tissue that initiates tooth formation? ||epithelial|
|Within the tooth bud, which type of cells (origin) are present and what do they differentiate into? ||epithelial cells: ameloblasts
mesenchymal cells: odontoblasts + cementoblasts|
|What initiates tooth formation? ||Interaction between the ameloblasts and odontoblasts|
|What component of the dental bud dictates the final shape of a tooth? ||enamel organ (epithelial origin)|
|From where is the blood supply of developing teeth derived? ||dental sac|
|in addition to the dental sac, where else does blood supply come from? ||blood supply also perforates the apical aspect of the
infundibulum in young equine cheek teeth and these apical infundibular blood vessels may
remain for a couple of years after dental eruption|
|What is Equine type 1 enamel? ||main constituent of the cheek teeth, consists of parallel rows of prisms lying between
parallel, dense interprismatic plates of enamel (very hard)|
|What is the disadvantage of hardness due to the parallel orientation of type 1 enamel prisms and interprismatic enamel? ||it is more susceptible to developing fractures|
|What is Equine type 2 enamel? ||solely consists of prisms (rounded on cross
section) which are oriented in three directions.|
|How does type 2 enamel compare with type 1? ||type 1 is harder|
|Where is type 2 enamel found on equine teeth? ||incisors|
|Where is type 1 enamel found on equine teeth? ||cheek teeth, infolded|
|What is the ratio of peripheral enamel length to tooth perimeter in mandibular cheek teeth? ||1.87|
|What is the ratio of peripheral enamel length to tooth perimeter in maxillary cheek teeth?
|What structures exist on the maxillary cheek teeth to make up for less peripheral enamel infolding? ||infundibulae|
|What is senile excavation? ||infundibula can wear out (often in the 09 or 10) causing the adjacent unsupported
primary and secondary dentine to wear very fast and the tooth to become hollow|
|What happens to the degree of infolding present on the periphery of teeth more apically?
age ||less enamel infolding near apices|
|Which type of dentin is most porous? ||secondary|
|Where is irregular secondary dentin deposited? ||laid down subocclusally in order to prevent exposure of the
pulps caused by dental attrition |
|Where is regular secondary dentin deposited? ||onto the inner dentinal walls by the odontoblasts that cover the pulp tissue|
|What are 2 types of tertiary dentin? ||repairative
|How many pulp horns do incisors, canines and PM1 have? ||one|
|How many pulp horns do the 07, 08, 09, & 10s have? ||5|
|How many pulp horns do the 06's have? ||six|
|How many pulp horns do the mandibular 11's have? ||seven|
|How many pulp horns do the maxillary 11's have? ||eight|
|What is the average thickness of subocclusal secondary dentin? ||1 cm|
|What is the variability/range of thickness of subocclusal secondary dentin? ||2 mm to 33 mm|
|What is the variation in the distance between the pulp and the mesial or distal tooth margin? ||1.3 to 10.8 mm|
|at which margin (mesial vs. distal) is the dentin thickness between the interproximal space and pulp tissue usually greater? ||mesial|
|What is is the main driver for deposition of
subocclusal secondary dentine? ||occlusal stimulation|
|What type of dental tissue comprises the primary occlusal surface of newly erupted teeth? ||cementum|
|What type of feed do horses eat faster (i.e. more chews per minute)? ||grass 100-105 chews/minute
hay 58-66 chews/minute|
|At what age do the deciduous 01's erupt? ||during the first week of life|
|At what age do the deciduous 02's erupt? ||4-6 weeks|
|At what age do the deciduous 03's erupt? ||6-9 months|
|At what age do the canine teeth erupt? ||4-6 years|
|At what age do the '05s erupt? ||~ 1 year|
|At what age are the deciduous 06's shed? ||~2.5 years|
|At what age do the 09's erupt? ||1 year|
|At what age do the 10's erupt? ||2 years|
|At what age do the 11's erupt? ||3-4 years|
|What is the average rate of eruption of horse teeth? ||2-3 mm/year|
|How many roots to maxillary cheek teeth have?
|How many roots to mandibular cheek teeth have? ||2|
|How many roots do the mandibular 11's have? ||3|
|What is the width of the maxillary arcades relative to the mandibular arcades? ||~23% wider on avg|
|What are the 3 major paired salivary glands of equids?
JVD Spring 2013 ||parotid, mandibular, polystomatic sublingual|
|Where are minor salivary glands present in horses?
JVD Spring 2013 ||Lips, tongue, palate, buccal regions|
|How much saliva does a correctly fed/hydrated horse produce?
JVD Spring 2013 ||10-12 L|
|What is another name for the parotid salivary duct?
JVD Spring 2013 ||Stenon's duct|
|In what age group of horses is the height of the curve of spee smaller?
JVD Winter 2009 ||older horses|
|In which part of the horse mouth are chewing forces the greatest? why?
2009 J biomech ||masticatory forces increased from rostral to caudal. due to distinct anatomical features of the equine dentition, i.e. the Curve of Spee, the position of the teeth, and the length of the mandible|
|What changes occur in chewing forces as horses age? why?
2009 J biomech ||masticatory forces decreased with age. This decrease was due to the reduced height of the Curve of Spee in older horses.|
|What is the widely accepted sequence of eruption for Equine Cheek Teeth?
2009 Eq Vet J ||M1, M2, PM2, PM3, M3, PM4|
|What are widely accepted emergence times of permanent PMs in horses?
2009 Eq Vet J ||2.5 years for PM2, 3 years for PM3 and
4 years for PM4|
|Which tend to erupt slightly sooner? Mandibular or maxillary permanent premolars?
2009 Eq Vet J ||Mandibular deciduous premolars were removed slightly earlier
than their maxillary counterparts|
|What findings evidencing sexual dimorphism in the timing of premolar ‘cap’ removal were noted?
2009 eq vet j ||fillies tend to shed their premolar ‘caps’ more than a month later than colts|
|What change is seen in the height of the curve of spee as horses age?
JVD winter 2009 ||it gets shorter|
|what correlation is noted between the height of the curve of spee and the masticatory forces?
JVD winter 2009 ||the higher the curve of spee, the larger the masticatory forces on the most caudal cheek teeth (and vice versa)|
|what negative consequences are reported in humans when the curve of spee is leveled?
JVD winter 2009 ||craniomandibular and myofascical dysfunctions with symptoms including pain, loss of hearing, vertigo, & others|