dental anomalies

Question 1

what is adontia? what kinds of adontia are there

Answer 1

Adontia is the condition of missing adult teeth. There can be partial or total

Question 2

is total adontia 1) common? 2) hereditary?

Answer 2

total adontia is Uncommon , but is Hereditary and effects primary and secondary teeth

Question 3

is partial adontia common? hereditary?

Answer 3

partial adontia is Very common, while is is Not hereditary

Question 4

What teeth are usually missing in adontia == and which of these is most commonly missing?`

Answer 4

Third molars (most common)

• MAX lateral incisors (2% population)
• MAND 2nd premolars (1% population) , are the most likely missing teeth

in primary teeth- the MAND central incisor is most commonly missing

Question 5

does adontia always occur bilaterally?

Answer 5

No, teeth can be missing either unilaterally or bilaterally

Question 6

What is the most commonly missing primary tooth?

Answer 6

the most commonly missing primary tooth is the primary MAND central incisor

Question 7

What is it called to have extra teeth in the dentition?

Answer 7

The condition of having extra teeth in entition is called having extra, or supernumerary teeth

Question 8

what teeth are most likely to be supernumerary?

Answer 8

the teeth mot likely to be supernumerary are the same teethmost likely to be missing in adontia.
the most likley supernumerary teeth are:
1) the third molar area
2) the MAX lateral incisor area
3) the MAND premolar area

Question 9

what is a mesiodens?

Answer 9

a mesiodens is a conical shaped supernumerary tooth that erupts from between the 2 central incisors.

a diastama (gap bt the central MAX incisors) could be an indication of a mesiodens unerupted

Question 10

if there is an extra MAND premolar (3rd most likely supernumerary tooth) where is it likely to erupt?

Answer 10

a supernumerary MAND premolar is more likely to erupt lingually rather than facially

Question 11

which teeth have a variation in develop know as peg-shaped —-?

1% of the population is impacted

Answer 11

the MAX lateral incisors may grow abnormally as a peg-shaped later (has one cusp and 1 pulp horn versus the usual 3)

other teeth can also be peg-shaped*

Question 12

what is a possible treatment to fix the aesthetics of a peg-shaped lateral

Answer 12

a crown could fix the peg-shaped lateral and make it more aesthetically pleasing

Question 13

what is gemination? - aka twinning””

Answer 13

gemination is the process where a tooth, from 1 bud, splits into 2 crowns that fuse. The result is 1 tooth with one root, one pulp chamber and one canal that has a double wide crown (ex, an incisor (highest prevalence of gemination)

impacts primary anterior teethmost commonly, but can impact secondary teeth as well

Question 14

are primary or secondary teeth impacted more by gemination? which teeth are most commonly afffected?

Answer 14

primary anterior teeth are more likely to geminate - such as primary incisors.

Adult, secondary dentition can geminate as well

Question 15

fusion: define

Answer 15

fusion is where 2 adjacent crowns from 2 distinct/ 2 individual teeth fuse and appear double width.The stillhave 2 roots (1 each) 1 canal each but crowns are double wide.

most common in primary anterior teeth, just like gemination

Question 16

how are gemination and fusion different

Answer 16

while both processes result in a double wide crown (and both processes occurmost frequently on anterior primary teeth) gemination origniates from one tooth that has dobule wide crown, whereas, fusion is the joining of crowns of 2 distinct teeth.

Question 17

how does counting teeth help determine bt gemination and fusion?

Answer 17

in gemination, if teeth are counted the right number of teeth will result (if double wide crown is still counted as “1”) // in fusion,if double wide crown is counted as one, it will seem as thoughthe dentition is missing a tooth (bc 2 teeth counted as 1)

Question 18

what is a paramolar?

Answer 18

Paramolar is a supernumerary molar usually small and rudimentary, most commonly situated buccally or palatally to one of the maxillary molars. – a paramolar can fuse to a molar

Question 19

describe 2 unusual cases of fusion - involving a mesiodens, and another involving a paramolar

Answer 19

a mesiodens can fuse to an incisor so there are 2 teeth with one crown,

or, a paramolar can fuse to a molar so that there is one large crown and the roots of the 2 teeth

Question 20

what is the dental anomaly caused by congenital syphillis? what doesit look like?

Answer 20

the dental anomally cuased by syphillis is called Hutchinson’s incisors – the incisors have a v-shaped notch in their incisors //

Question 21

what is is called when molars have a bunch of tiny tubercles on them?

Answer 21

molars with tiny tubercles are called mulberry molars

Question 22

whatis a tuberculum intermedium?

Answer 22

a tuberculum intermedium is an extra cusp that develops as a third lingual cusp (nestles bt the 2 normally present L cusps) on MAND molars

Question 23

what is it called when an extra cusp develops on the distal end of a MAND st molar?

Answer 23

a 6th cusp developing onthe distal end of a MAND 1st molar is called a tuberculum sextum

Question 24

what is a talon cusp, and how can it be differentiated from an overgrown marginal ridge?

Answer 24

a talon cusp is similar to an extra lingual cusp – it is a large tubercle , a claw-shape projection that grows off of the incisor on the lingual aspect. .. talon cusps usually have their own pulp horn.. so as treatment can only smooth- to get rid of it, need a root canal.

to distinguish from an overgrown marginal ridge,which can look similar, overgrown marginal ridges will have a GROOVE likely extending onto the root surface

Question 25

what is macrodontia and what teeth does it usually impact?

Answer 25

macrodontia is unusually large teeth (pituitary giants) and impact

• incisors
• and canines

Question 26

what is microdontia and what teeth are impacted?

Question 27

what do shove;-shaped incisors look like, and what ethnic groups have these more commonly?

Answer 27

shovel-shpaed incisors look like shovels – the marginal ridges are rounded and curved like a cupped hand.

shovel shaped incisors are more commonly seen in american indians, asain, mongoloid,and eskimo peoples

• not really an anomally, more of a racial trait
• double shovel can exist (rare) that there is a shovel (cupped hand shape on both the lingual and facial sides of the incisor

Question 28

define dilaceration

Answer 28

dilaceration is severe bending that occurs at the CEJ level.

flexion is another severe bending condition but it occurs at a different level- occurs ar any other level ofthe root other than the CEJ

Question 29

what s flexion?

Answer 29

flexion is a form of severe bending of the root that occurs at any level of the root other than the CEJ (CEJ severe bending is called dilaceration)

Question 30

where are enamel pearls most often found?

Answer 30

enamel pearls are most often found at the furcation area of roots

Question 31

what is taurodontia

Answer 31

this is a “bull tooth”.. sen more ethnically in m\neanderthals, native americans, and eskimos.

occurs in the molars .. looks like molar with large pulp cavity and not constriction at the CEJ.. the tooth has a complex root canal

Question 32

a radiograph shows a small tooth encapsulated in another tooth. what is this called?

Answer 32

when a tooth is encapsulated in another tooth ,the condition is called “dens in dente”
treatment involves sealing the tooth with composite so that the external environment cannot enter via the envagination site

Question 33

what is hypercemetonsis and what is it caused by?

Answer 33

hypercementosis is the thickening of cementum - AS IN, THERE IS EXCESS CEMENT ON the tooth) .. can casue webed roots (like the look of human webbed toes).
this can b caused by trauma, or by metabolic dysfunction

Question 34

what is it called when the cementum of adacent teeth join after the teeth have erupted?

• how is this condition different from fusion? or is it the same thing?

Answer 34

the situation where the teeth have erupted, and then the cementum of these adj teeth join is called “ concrescence of roots”

(different from fusion that occurs BEFORE eruption of teeth)

Question 35

what may cause dwarfed roots?

Answer 35

dwarfed roots can be caused by hereditary guides, or due to orthodontic movement (if roos are moved too soon bf they are fully grown, the roots can shut down and stop growing – recall, upon eruption roots are about 2/3 developed and then take the next 3 years to finish developing..)

Question 36

where are acessory roots seen most often?

Answer 36

accessory roots = extra roots, are most often seen on MAND canine and MAND premolars (which will have a facial and L root..) accessroy roots also ocur on third molars, and MAND 1st and 2nd molars, MAX 1st premolar, and rarely on primary MAX canine ((((soooo accessory roots more common in MAND teeth!)))))

Question 37

what is transposition?

Answer 37

transpostion is a tooth location anomally where teeth swiitch locations with another tooth (ex/ MAND canines sit where there should be MAND Lateralincisors and the AMND L incosirs are inthe place of the MAND canines

NOT necessarily bilateral

Question 38

define ectopic tooth position

Answer 38

ectopic tooth position is when a tooth erupts elsewhere other than the arch

Question 39

what is transmigration?

Answer 39

transmigration is a tooth location anomally where the tooth erupts elsewhere other than its normal place (a word to encompass situations that are not transposition nor ectopic)

Question 40

is it possible for a tooth to grow such that the side that is normally facing buccally growns to face lingually? what is that called?

Answer 40

YES! it is possible for teeth to ROTATE and grown in differently than normal development

Question 41

what is ankylosis?

Answer 41

ankylosis is failure to complete eruption due to trauma or infection —- what is happens:
periodontal ligament is lost and the root fuses to the alveolar bone

Question 42

what is enamel dysplasia?

Answer 42

big topic - see handout for all types and indications:

enamel dysplasia means abnormal enamel formation –
diff types of enamel dyslpasia:
>ameleogenesis imperfecta (hereditary or parital lack of enamel in primary and secondary dentitions) - teeth look brown spotted and are Very decayprone
= corwning = treatment
>fluorosis (too much fluoride, mottled appearance)
>enamel damage due to high fever – crowns appear very brown.. crowns forming 6 years bf eruption.. so if high fever at time, enamel w defective formation
>focal hypermaturation

dentin dysplasia also exists where dentin has abnormal formation
types:
>dentiogenesis imperfect
>tetracyclin stain

Question 43

are teeth with fluorosis caries prone?

Answer 43

No, teeth with fluorosis are NOT caries prone. fluorosis = too much fluoride.. causes teeth to look mottled and pitted, however, they are ver strong and unlikely to get caries

Question 44

focal enamel hypoplasia: discuss:

Answer 44

focal hypoplasia or hypomaturation – aka turner’s tooth

causes:
from local trauma or infection in primary tooth

Question 45

localized focal enamel hypoplasia is usually caused by what?

Answer 45

localized focal enamel hypoplasia is usually caused by infection in the primary tooth – what occurs is that a smal bit of decay can progress fast (esp primary teeth bc of thin enamel and dentin), the decay can abscess and impact the growing permanent tooth

Question 46

what causes dentinogenesis imperfecta?

Answer 46

both ameleogenesis (enamel) and dentinogenesis imperfect are HEREDITARY and impact PRIMARY AND SECONDARY dentition

Question 47

what does dentinogenesis look like?

Answer 47

dentinogenesis: the teeth look shiny, .. enamel has no support so chips and breaks easily.

in an x-ray, no pulp chamber is visible in patients with dentinogenesis imperfecta == no pulp chamber is visible

Question 48

what is a conditionthat could cause teeth to appear green in color? what causes this to occur?

Answer 48

a condition that can cause teeth to appear greenis called Biliary atrisia. this is another type of dysplasia =an abnormal development)

biliary atrisa involves a blockage betweenthe liver and gall bladder

Question 49

what is a tetracyclin stain?

Answer 49

a tetrcyclin stain is a stain that is caused by tetracyclin- a drug given to pregnant women as an antibiotic. the tetracyclin stains the teeth of both the mother an the baby bc crosses placental barrier.

treatment = bleachingm to an extent

Question 50

what are some possible injuries that teeth can sustain?

Answer 50

examples of injury to teeth include:

erosion, abrasion, abfraction, erosion

Question 51

define attrition:

Answer 51

attrition i the wear of enamel and dentin due to oposing tooth contact (bruxism - extreme)

Question 52

define abrasion:

Answer 52

the wear of tooth structure by mechanical means - toothbrush, chewing tobacco..

Question 53

whatis it called when a tooth bends due to heavy occlusion- and the enamel chips off at the cervical?

Answer 53

the condition where a tooth bends due to heavy occlusion and enamel chips of at the cervical is called abfraction

Question 54

what is erosion, pertainin to denttion?

Answer 54

erosion for teeth is the wear of tooth structure from CHEMICAL agents - like citric acids, carbonated beverages, bulimic pts. etc

Question 55

what is is called when teeth are damaged by chemical agents?

Answer 55

when teeth are damaged by chemical agets,such as citric acid or carbonated beverages, it i called erosion

Question 56

whatis bruxism

Answer 56

bruxism is an extremem form of attrition. most teeth occlude for about 20 min a day during mastication. in bruxism, pts have 40 min of contact every nhour of the night grinding w 25 lbs of load (accordingto NY times!) – teeth get severly worn down

Question 57

what is a possible treatment for bruxing pateints

Answer 57

to fix the teeth would need crowns – corwns will seal the dentin and enamel and prevent further loss while maintaining the vertical dimension of the face

Question 58

is primary dentition bruxism seen as a problem?

Answer 58

in terms of dentition, not really. primary teeth will exfoliate,and further during mixed dentition the bite does not properly occlude.

Question 59

what is class 2 occlusion?

what is class 3 occlusion

what is ideal occlusion?

Answer 59

class 2 occlusion is when there is an overbite – the maxillary arch reaches too far anteriorally

class 3 occlusion is when there is an underbite, the mandible extends anterior to the maxillary arch

ideal occlusion is class 1 occlusion. this occurs with maximum intercupidation, canine guidance, and has the MAX canine cusp aling bt the MAND canine and MAND 1st premolar.. also, the MBcusp of MAX 1st molar fits into the mesial groove of the 1st MAND molar