Dental Anatomy Flashcards
which anterior teeth have an offset cingulum?
mandibular lateral
mandibular canine
maxillary central
Which anterior teeth have a cingulum located in the center of the lingual surface?
maxillary lateral
maxillary canine
mandibular central
What are 3 things common to all mandibular incisors?
- indistinct cingula without any grooves or pits
- incisal edges are lingual
- facial surfaces are convex
How do the marginal ridges differ between the mandibular central and lateral incisors?
the mandibular lateral has a mesial marginal ridge that is longer than the distal.
The mandibular centrals have marginal ridges that are equal in length
Which teeth/view are viewed as triangles?
all anterior teeth from the mesial and distal
Which teeth/view are viewed as trapezoids with the longest uneven side toward the occlusal?
All teeth from the facial or lingual
Which teeth/view are viewed as trapezoids with the SHORTEST uneven side toward the occlusal?
maxillary posterior teeth from the mesial or distal
Which teeth/view are viewed as rhomboids?
All mandibular teeth from the mesial or distal
What is the shape of the pulpal canal in a mandibular lateral incisor?
it is wider in the mesiodistal direction in the coronal canal and wider in the labiolingual direction in the mid-canal
What is the only anterior tooth that has a distoincisal angle that is just as sharp as the mesioincisal angle?
Mandibular centrals
What is the only anterior tooth that has a pulp chamber that is wider mesiodistally than labiolingually?
maxillary centrals
Which anterior tooth contacts both anterior and posterior teeth in maximum intercuspation?
maxillary canine
On a maxillary canine, where is the cusp tip in relation to the long axis of the tooth?
it is displaced LABIALLY and MESIALLY
On a maxillary canine which side (mesial or distal) has a greater curvature?
mesial
On a maxillary canine, which cusp ridge is more straight?
mesial
On a maxillary canine, which cusp ridge is longer?
distal is longer
On a maxillary canine, which direction does the root curve USUALLY
to the distal, but this is not always true
What is unique about the facial surface of canines?
it contains a labial ridge
What is unique about the occlusion of the canine?
It is the only cusped tooth that features a functional LINGUAL surface instead of a function occlusal surface.
What is the eruption sequence for maxillary permanent teeth?
781-00*62
stars have a range of 2 years instead of 1
What is the eruption sequence for mandibular permanent teeth?
679-0161
stars have a range of 2 years instead of 1
what are some differences between mandibular and maxillary canines?
Mandibular: mesial border (contact area) is much straighter (Maxillary: none of the borders are really that straight)
Mandibular: The mandibular canine has a continuous convex facial surface when viewed from the mesial or distal
What is the longest tooth in the mouth?
maxillary canines
On a canine, which dimension is the longest between faciolingual or mesiodistal?
faciolingual is longer
Which tooth has the longest crown of any teeth?
mandibular canine
Which part of the crown of the mandibular canine is nearly parallel to the long axis of the tooth
The mesial border
When does calcification of the roots occur?
by age 3 or 4
How much of a root is formed when a tooth erupts?
2/3
What is the order of eruption for maxillary primary teeth?
8, 9, 16, 13, 25
44668 (this is the range of each number)
What is the order of eruption for mandibular primary teeth?
6, 10, 17, 14, 23
46648 (this is the range of each number)
Between boys and girls, who’s teeth normally erupt first?
girls
Between maxillary and mandibular, which teeth normally erupt first?
mandibular
Between skinny and fat kids, who’s teeth usually erupt first?
The skinny kids teeth erupt first so they can eat more food. :)
When in utero do crowns of teeth begin to calcify?
between 4-6 months
How long does it take for a primary tooth to calcify when it begins?
10 months
How long does it take for a root to finish developing after it erupts into the oral cavity?
1 year
What is the palmer notation for primary teeth?
EDCBA / ABCDE
EDCBA / ABCDE
What is the difference between the FDI system of numbering primary vs permanent teeth?
primary quadrants are 5,6,7,8
permanent quadrants are 1,2,3,4
What is another name for the ugly duckling stage?
broadbent’s phenomenon or physiologic median diastema
What causes the ugly duckling stage?
erupting canine puts mesial pressure on lateral, which tilts the roots of the centrals mesially, creating a diastema in the centrals
What is the rule of 4? When would you start it?
4 new teeth every four months starting at 7 months. so at 11 months a child should have around 8 teeth (centrals and laterals)
*This is a generalization!
If teeth are present at the time of birth, what is that called?
natal teeth, these are not real teeth and lack roots
What are neonatal teeth?
different from natal teeth, neonatal teeth erupt within 30 days after birth.
what is the summary of contact points for the maxillary teeth?
IJ, JM, JM, MMMMMM
I just jacked michael jackson’s moped
What is the summary of contact points for the mandibular teeth?
II, II, IM, MMMMMM
Where is the facial height of contour from the facial AND lingual aspects on all teeth?
on the cervical third
Where is the lingual height of contour on all teeth?
anterior - cervical third
posteriors - middle third
When viewed occlusally, where is the proximal contact of posterior teeth?
towards the buccal a bit
What is concrescence?
When the roots of teeth get melded together by excessive cementum
What is plica fimbriata?
Little doobys that hang from the bottom of the tongue. They are part of normal anatomy.
What is a heterodont?
teeth that have different morphologies and functions
What is diphydont?
having two sets of teeth. Humans are these with primary and permanent dentition
What is homodont?
teeth that are all alike
what is hypsodont?
long teeth
what is polyphydont?
teeth continually being replaced like in fish and reptiles
Which teeth are most commonly missing?
third molars, maxillary laterals, mandibular second premolars
What is the difference in enamel hypocalcification and enamel hypoplasia?
hypocalcification - normal amount, but soft
hypoplasia - less amount, but hard
What instrument do you use to measure tooth dimensions?
a Boley gauge
What is the most stable and most easily reproduced position of the mandible?
centric relation
What are border movements?
The maximum limits that a mandible can move. functional movements occur within these.
What is the maximum opening distance a person can have in general?
50-60 mm
maximum lateral movements are generally how much?
10-12mm
maximum protrusive movements are how much?
8-11 mm
maximum retrusive movements are how much?
1 mm
Where does chewing function take place?
about a few millimeters of ICP and CO
What muscle is the principle positioner of the mandible during elevation?
The temporalis muscle
What is the insertion of the temporalis muscle?
coronoid process of mandible
What are the three actions of the temporalis muscle?
- elevation of mandible
- retrusion of mandible
- helps in lateral excursion of the mandible
What is it called when a mandible is moved laterally?
transtrusion
What are the two components to transtrusion?
laterotrusion - lateral movement of the working condyle
mediotrusion - medial movement of the non-working condyle
what is bennett movement?
the lateral movement of the working condyle during a transtrusion.
What is bennett angle?
The medial movement of the non-working condyle during transtrusion
Which root of a maxillary first molar commonly has 2 canals instead of one?
mesiobuccal root
What is an important aspect to remember when it comes to the pulp chamber of the maxillary first molar?
the mesiobuccal and mesiolingual pulp horns are higher than the palatal and and distofacial horns.
What are the most common bifurcated teeth?
the maxillary first premolars and the mandibular molars
Which root tip is the smallest on a maxillary first molar?
distobuccal
What are the three longest maxillary roots in the mouth?
- maxillary canine (17mm)
- second premolar (14mm)
- palatal root of maxillary first molar (13mm)
How do maxillary 2 molar roots differ from first molar roots?
The maxillary 2nd molar roots are less divergent than the first molar roots and the palatal root is straighter
How many cusps do mandibular molars have in general? How many do maxillary molars have?
4, 3
What shape do mandibular molars have when viewed occlusally?
rectangular
What shape do maxillary molars have when viewed occlusally?
rhomboid
Mandibular molars have pits and grooves on what surfaces?
occlusal and buccal
Maxillary molars have pits and grooves on what surfaces?
occlusal and lingual
How do the crown dimensions differ in mandibular molars vs maxillary molars
mandibular molars are wider mesiodistally than buccolingually
Maxillary molars are wider buccolingually than mesiodistally
How do the cusp shapes differ in mandibular molars vs maxillary molars?
mandibular molars have cusp tips that are thee same height. maxillary molars have one large cusp and one small cusp
Which molar has a transverse ridge?
mandibular molars
Which molars have an oblique ridge?
Maxillary molars
What cusp tips do the oblique ridge connect to?
the mesiolingual and distobuccal
Relative to the long axis of the root, what way are mandibular molars tilted?
lingually AND distally
On which side is it harder to place scaling instruments subgingivally on a mandibular molar?
on the lingual side because the molar is tipped to the lingual
Which molars will generally have a fissured groove called a developmental groove?
lingual surface of maxillary molars
The distolingual cusp on permanent maxillary molars is also called a what?
talon cusp
What is the best way to distinguish a first, second and third molar?
The distolingual cusp gets smaller as you move back in the mouth
Which way will the mandible deviate if there is an side with injury?
toward the affected side always
What relationship are the teeth in class I occlusion?
The mesiobuccal cusp of the maxillary first molar sits in the mesiobuccal groove of the mandibular first molar.
Most mandibular teeth, except central incisors, contact two teeth from the maxillary arch. Which two teeth are they?
The counterpart and the tooth mesial to it.
The curve of wilson is ______ in the mandibular arch and _________in the maxillary arch.
concave (in mandibular arch)
convex (in maxillary arch)
What is another name for anterior guidance?
anterior coupling
What is overjet
the distance between the central incisors in occlusion
What is overbite
How much the maxillary central incisors hang over the mandibular incisors.
Reducing the curve of spee can ______ the verticle overlap of the teeth.
reduce
What is the sphere of monson?
it is a plane created from both the curve of spee and the curve of wilson.
What type of lever is the mandible in the TMJ?
class III lever
Where is the fulcrum of mandibular movement?
the head of the mandibular condyle
Which lining mucosa of the oral cavity does NOT have submucosa?
ventral tongue
What is the one area of lining mucosa that has keratinized epithelium?
vermillion border of the lip
What are the 5 principle fibers?
- alveolar crest group
- apical (periapical) group
- oblique group
- horizontal group
- interradicular group
What are the 5 gingival fibers?
- circular group
- dentogingival group
- alveologingival group
- dentoperiosteal group
- transseptal group
Where is the thinnest portion of PDL?
Near the middle 1/3 of the root
What type of elastic fiber is present in the PDL?
Oxytalan
What type of elastic fiber is present in the gingival tissues?
elaunin
T/F epithelial cell rests of Malassez are present as isolated islands or clusters throughout the cementum.
False. They are in clusters or interlacing strands on the root surface.
Where are epithelial cell rests of Malassez found in more abundance?
Near the apical area and cervical area.
What connect the epithelial cell rests of Malassez together?
hemidesmosomes
What are the effects of aging on the periodontium?
- decrease keratin
- flattened rete pegs
- increase density of CT
- Coarser gingiva
- Decreased fibroblasts in PDL
- 5x-10x increase in cementum width
In a healthy sulcus, the amount of gingival fluid is _______
small
The amount of collagen in a tissue can be determined by the tissues ___________ content
hydroxyproline
Where does the dental lamina come from?
It arises from the oral epithelium. (ectoderm)
What surrounds the dental lamina?
mesenchymal cells
What is the specific shape of the enamel rod dicated by?
The Tome’s process of the ameloblast.
What is the difference between Tome’s process and Tome’s fibers?
Tome’s process is picket-fence look on ameloblasts.
Tome’s fibers are extensions of the odontoblast into the dentinal tubules.
What are two proteins found in enamel?
Amelogenins and enamelins
Which tooth structure is known to have a selctively permeable membrane and lets water and certain ions pass through?
ENAMEL
What are enamel spindles?
Short dentinal tubules that crossed into enamel.
What are enamel lamellae?
they look like cracks that traverse the entire crown from DEJ to the surface.
What is the inner core of the enamel organ
stellate reticulum
What does it mean if cold relieves symptoms of a toothache?
That there is partial necrosis of the dental pulp.
What origin is the odontoblast?
ectomesenchyme
What developmental defects can happen in the initiation stage of tooth development?
anodontia or supernumerary teeth
What developmental defects can happen in the cap stage of tooth development?
dens in dente, gemination, fusion, tubercle formation
What developmental defect can happen in the bell stage of tooth formation?
macrodontia/microdontia
What developmental defect can happen in the apposition stage of tooth formation?
enamel dysplasia
concrescence
enamel pearls
Which dental tissue most closely mimics bone?
cementum
Which dentin is formed in the dentinal tubules? What is unique about this dentin?
Peritubular dentin. It is the most highly mineralized dentin.
What is a sulcus in a tooth?
a V-shaped depression on the occlusal surface of posterior teeth
What is a fossa in a tooth?
An irregular depression or concavity found both on anterior and posterior teeth
Where is the largest incisal/occlusal embrasure?
between the maxillary canine and the first premolar
Where are transverse ridges the most common?
On mandibular molars and maxillary premolars
Which direction does an oblique ridge run?
From distobuccal to mesiolingual
How many lobes are in the following teeth? anterior: premolars: First molars: Second molars: Third molars:
- anterior: 4
- premolars:4 except mandibular 2 premolar: has 5
- First molar: maxillary has 4 (5 if cusp of carabelli) mandibular has 5
- second molar: 4
- third molar: at least 4, but can vary
What are the accessory ligaments of the TMJ?
sphenomandibular and stylomandibular ligaments
What is the attachment of the stylomandibular ligament?
angle of mandible
What movement does the TMJ ligament protect against?
posterior and inferior displacement
What are collateral ligaments? What is another name for them?
“discal ligaments” they go from the articular disc to medial and lateral poles of the condyle. They restrict movement of the disc away from the condyle.
What are the two parts of the lateral pterygoid muscle? What are their attachments?
superior belly - attaches to joint capsule, articular disc, and neck of condyle
inferior belly - neck of condyle
What are the functions of the inferior and superior belly of lateral pterygoid muscle?
inferior belly - bilateral is protrusion. unilateral is lateral movement.
Superior belly - stabilizes mandible during closure
*when inferior bellies contract with with depressor muscles, the mouth opens.
The posterior aspect is of the condyle is ________ while the anteroinferior aspect is _________.
convex, concave
Are the condyles symmetrical?
No. They are also not identicle
What stages of sleep does bruxism occur in?
From deep to light sleep, not light to deep. This happens about every 90 minutes.
How long does one episode of sleep bruxism last?
about 5 minutes
Where is the retrodiscal tissue located?
posterior to the articular disc. It attaches to the posterior thickening of the disc.
Which direction does the shape of the head of the condyle run?
mediolaterally
What is adapted centric posture?
Its a position of the condyle that has been having problems that is stable for both the mandible and maxilla.
If the collateral ligaments are torn, which direction will the articular disc be displaced and why?
anteromedially, because the lateral pterygoid muscle attaches to the anterior part of the disc. Without the ligaments to hold the disc to the condyle, the lateral pterygoid muscle will pull the disc towards itself in an anteromedial direction.
Is the articular disc vascular and innervated?
No, except only the extreme periphery of the disc is slightly innervated.
How far must one open their mouth before the movement of the condyle changes from rotational to translational?
20mm
