Abnormalities of teeth

Question 1

Incomplete or defective enamel formation

Various causes; variety of environmental influences: Turner hypoplasia; antineoplastic agents; fluorosis; syphilis; etc

Restorative treatment as indicated

Answer 1

Enamel Hypoplasia

Ameloblasts are very easily affected/influenced by environment: high fever at young age

Question 2

“Physiological” wear due to tooth to tooth contact during occlusion

Answer 2

Attrition

Question 3

Tooth structure loss secondary to external agent; variety of patterns

Answer 3

Abrasion

ex – toothbrush abrasion

Question 4

Cupped-out depression of occlusal surfaces or cusp tips; associated with regurgitated gastric acid or dietary acid

Answer 4

Erosion

Question 5

Wedge-shaped defect limited to cervical area; bruxism associated

Answer 5

Abfraction

Question 6

Treatment for attrition, abrasion, erosion, abfraction

Answer 6

Early diagnosis and intervention

Construction of occlusal guards

Inform patients regarding tooth loss from acidic foods, reflux, etc.

Lost tooth structure- replaced with variety restorative procedures

Question 7

Relatively rare

Destruction of tooth structure accomplished by cells located in the dental pulp

May be idiopathic or subsequent to trauma

Teeth may appear pink

Answer 7

internal resorption

Treatment: Endo therapy prior to perforation  once communication with PDL, poor prognosis

Question 8

Relatively common

Destruction of tooth structure accomplished by cells located in the PDL

Causes: chronic inflammation, cysts, neoplasms, trauma, re-implantation of avulsed tooth, impactions, orthodontic forces, idiopathic.

Answer 8

external resorption

tx - depends on extent, extraction may be necessary

Question 9

Surface accumulation of exogenous pigment which can typically be removed by prophylaxis.
ie- tobacco, food and beverages, bacterial, medications, etc

Answer 9

extrinsic stains

Question 10

Endogenous material is incorporated into developing teeth  Deposition of circulating substances including drugs (tetracycline) and blood pigments (Rh incompatibility)  Cannot be removed by prophylaxis

Answer 10

Intrinsic stains

Question 11

Reduced number of teeth

Most common dental developmental anomaly; uncommon in deciduous dentition

Genetic vs. environmental etiology

Patient should be evaluated to determine the cause

Answer 11

Hypodontia

Most often affects: third molars, second premolars, lateral incisors

Question 12

lack of 6 or more teeth

Answer 12

Oligodontia

Question 13

total lack of tooth development

Answer 13

Anodontia

Question 14

Presence of “supernumerary teeth”

Occurs in 1-3% of the population  more frequent in permanent relative to deciduous dentition.  95% maxilla/mandible?,
 Terms: mesiodens; distodens; paramolar

Answer 14

Hyperdontia

95% maxilla, usually anterior

May affect occlusion, hygiene; may be unesthetic

 Tx - removal may be indicated to avoid complications related to normal eruption and occlusion

Question 15

Small teeth, may also affect shape

Most commonly affected teeth:

 Tx – restorative dentistry as indicated

Answer 15

Microdontia

maxillary laterals (peg) and third molars

Question 16

large teeth  Uncommon  associated with various syndromes and systemic disease

Answer 16

Macrodontia

Question 17

Partial division of single tooth bud; crown appears split  Usually seen in anterior teeth  Tooth count is normal

Answer 17

Gemination

central is normal coming out of gingiva then splits into two at incisal edge

Question 18

2 tooth buds merge to form single large tooth  fused teeth have separate root canals, but share cementum and dentin  Reduced number of teeth in arch

Answer 18

Fusion

2 different roots coming out of gingiva, but crowns together with dentin and cementum

Question 19

Uncommon condition; characterized by the fusion of two teeth by cementum alone 

May be difficult to detect radiographically  More frequent in posterior _  Clinically significant if one of the involved teeth must be extracted

Answer 19

Concrescence

More frequent in posterior maxilla

Question 20

Rare condition that primarily affects the maxillary incisors  Basically an exaggerated cingulum

Answer 20

talon cusp

1/2 to CEJ it is a talon cusp
Not half way it is a cingulum

 Significant if the talon cusp interferes with occlusion  Gradual removal to allow for secondary dentin formation

Question 21

Extra cusp in central developmental groove  Premolar teeth most commonly affected; mandibular predominance

Tooth often becomes non-vital, presumably due to attrition or trauma to cusp

Answer 21

Dens Evaginatus

Question 22

Dens Evaginatus - Extra cusp in central developmental groove

most commonly found where

Answer 22

Premolar teeth most commonly affected; mandibular predominance

Question 23

Uncommon condition that primarily affects the maxillary lateral incisor “Tooth within a tooth”, perhaps due to invagination of tooth bud Quite variable in severity Affected tooth often becomes non-vital shortly after eruption

Answer 23

Dens Invaginatus aka dens in dente

Question 24

Enamel Pearl
 Droplets of ectopic enamel
where do we find them?

 Pearls may have dentin and pulp horns  May be detected by probing, if mistaken for calculus, can lead to exposure

Answer 24

 Furcations of maxillary or mandibular molars

Will have a dome shaped radiolucency - because PDL attachs to cementum not enamel

Question 25

Uncommon; radiographic finding
 Enlargement of the body and pulp chamber of a multirooted tooth; apical displacement of pulpal floor and furcation
 Similar to bovine dentition
 Result of chromosomal alterations; associated with various syndromes

Answer 25

Taurodontism

Effects usually all multi-rooted teeth in quad

Question 26

Hypercementosis

 Unusual; incidental radiographic finding
 Adults
 Asymptomatic deposition of excessive cementum
 Local and systemic factors
 most cases are sporatic
 strong association with _ Disease of Bone

Answer 26

Paget’s

hypercementosis - No treatment necessary  Occasional complications with extraction

Question 27

Unusual; radiographic finding
 Curvature/bend of tooth roots
 Etiology: trauma to developing tooth
 Complications: Extraction or RCT may be difficult

Answer 27

dilaceration

Question 28

Group of uncommon genetic disorders affecting enamel of teeth
 Varied patterns of inheritance
 Weak enamel is easily lost
 Affects both primary and permanent teeth

Answer 28

Amelogenesis Imperfecta

Clinical implications and management vary according to the subtype and severity  Dental restorative care to address aesthetics, sensitivity, caries, loss of vertical dimension

Question 29

Amelogenesis Imperfecta _

inadequate deposition of enamel matrix

Answer 29

Hypoplastic

1st step in forming enamel

Question 30

Amelogenesis Imperfecta _
incomplete mineralization

This type affects primary and permanent

Answer 30

Hypomaturation

enamel matrix laid down correctly, but not maturation

Question 31

Amelogenesis Imperfecta _

no significant degree of mineralization

Answer 31

Hypocalcified

does mature at all

Question 32

Amelogenesis Imperfecta

Enamel looks abnormal

clinically? radiographically?

Answer 32

 Clinical: rough, smooth, pitted, pigmented, or “snow-capped”

 Radiographic: thin enamel of normal or decreased density; normal root and pulp morphology

Question 33

Uncommon
 Autosomal dominant inheritance, Due to mutation of DSPP gene

 Affects both primary & secondary dentition
 Results in abnormal dentin formation

Answer 33

Dentinogenesis Imperfecta

Due to mutation of DSPP gene  “dentin sialophosphoprotein” – one of the major non-collagenous proteins of dentin

Management depends on the severity of gene expression  May require little restorative care, however implants and/or overdentures are necessary in many cases

Question 34

Dentinogenesis Imperfecta

clinically? radiographically?

dentin is very soft
Enamel chips off and a lot of attrition

Answer 34

Clinical:  Teeth appear translucent; “Opalescent teeth”  Enamel is normal, but poorly supported; rapid attrition of dentition is often seen

 Radiographic:  Bulbous crowns and obliteration of pulps, constriction at cervical CEJ

Note: Similar dental changes may be seen with osteogenesis imperfecta

Question 35

Dentin Dysplasia
Autosomal dominant inheritance, 2 types

_ type : roots are very short “rootless teeth”, obliteration of pulp (crescent-shaped remnant in crown), periapical radiolucencies

Answer 35

Type I: Radicular Dentin Dysplasia

~Teeth may appear normal clinically~

Question 36

Dentin Dysplasia
Autosomal dominant inheritance, 2 types

_ type : Thought to be related to dentinogenesis imperfecta  Enlarged pulps with “thistle tube” appearance, pulp stones

Answer 36

Type II: Coronal Dentin Dysplasia

~Teeth may appear normal clinically~