Anatomy - Week 12.2 PP

Question 1

Tooth Anomalies - Dental Assistant Role with them

Answer 1

• Recognition of anomaly
  -Patient education
  -Treatment considerations

Question 2

Types of Developmental Disorders

Answer 2

-Inherited disorders (genetic) are different from developmental disorders because they are caused by an abnormal gene
*a congenital disorder is one that is present at birth
*either inherited or developmental; however, exact cause of most congenital abnormatilies is un known

Question 3

Genetic Factors

Answer 3

Malformations that are often the result of genetic factors such as chromosoal abnormalities

Question 4

Environmental factors

Answer 4

Called teratogens; include infections, drugs, and exposure to radiation

Question 5

Distrubances in Jaw Development - occur during development of the jaw

Answer 5

-Macrognathia - abnormally large jaw

Micrognathia - abnormally small jaw

Exostoses - a benign bony overgrowth projecting outward from the surface of a bone (usually on maxillary)

Torus palatinus - a bony overgrowth at the midline of the hard palate

Torus mandibularis - a bony overgrowth on the lingual surface of the mandible

Question 6

Disturbances in Lip, Palate,
and Tongue Development

Answer 6

Cleft lip - results when the maxillary and medial nasal processes fail to fuse

Cleft palate - results when palatal shelves fail to fuse with primary palate

Cleft uvula - the mildest form of cleft palate

Ankyloglossia - often called tongue-tie; results in a short lingual frenum that extends to the apex of the tongue

Question 7

Tooth Anomalies

Answer 7

• can happen during differnt stages of development
• length of effect
• heriditary or environmental cause
• more often in permanent dentition

Question 8

Etiology of Anomalies

Answer 8

Stages of Development

1. initiation
2. Proliferation
3. Histo-differentation - difference of cell type
4. Morpho-differentiation - difference of shape
5. Apposition
6. Maturation

Question 9

Abnormal Number of Teeth

Answer 9

-Initiation stage of development

• lack of initation within the dental lamina
  *absence of a single tooth or an entire dentition

-Associated with… (during prego)
*Ectodermal dysplasia
*Endocrine dysfunction
*Systemic disease
*Radiation

Question 10

Anodontia (Hypodontia)

Answer 10

-Partial or complete abesense of teeth

-Commonly include:
*permanent third molars
*maxillary lateral insicors
*Mandibular second premolarrs

Question 11

Hyperdontia

Answer 11

-Supernumary tooth or teeth

-Commonly found:
*Between permanent maxillary icisors
*Distal to third molars

-Etiology:
*Hereditary

• more genetically common than Hypodontia

Question 12

Mesiodens

Answer 12

small extra central incisor

erupts between two central incisors

Question 13

Abnormal Size

Answer 13

-Bud stage of the development (proliferation stage)

• abnormal proliferation of the tooth bud can cause a single tooth or multipe teeth or an entire dentition to be larger or smaller than usual
• generally genetic with partial
• endocrine dysfunction associated with complete (during prego)

Question 14

Macrodontia

Answer 14

-abnormal increase in tooth size

• childhood hyperpituitartism (gigantism) can cause

Question 15

Microdontia

Answer 15

-Complete miccrodontia - extremely RARE!
*all teeth small
*associated with hypopituitarism or Down’s Syndrom

• True Partial Microdontia
  *heritidary factors involved
  *commonlly affects the permanent maxillary lateral insicors and permanent third molars

Question 16

Abnormal Shape

Answer 16

• later stages of tooth development (/Aposition- Cap-Maturation)
• Proliferation of Morphodiffrentiation process
• Can pressent as abnormal crown or root shape

Question 17

Dens in Dente

Answer 17

-Cap stage
-Enamel organ invaginates into the dental papillae
-Commonly affects permanent lateral incisor
-Etiology-Hereditary factors

Question 18

Gemination

Answer 18

-Cap Stage (Maturation)
-The tooth germ tries to divide but develops a large single-rooted tooth with one pulp cavity and “twinning” in the crown of anterior teeth
-**The correct number of teeth will be present **
-Etiology - Hereditary
-an unsuccessful attempt is indicated by an incisal notch
-sometimes looks like just a notch, however, when you take an Xray it will become clear

Question 19

Fusion

Answer 19

-Cap Stage
-Union of two adjacet tooth germs
-Results in a large tooth with two pulp cavities
-One fewer tooth in the dentition
-common on anteriors in primary dentition
-Etiology - Presssssuuuree!! Either during pregancy, during fetal growth, or right at birth

Question 20

Tubercle

Answer 20

-Cap Stage
-Small rounded enamel extension
-commonly found on posterior occlusal surfaces or anterior lingual surfaces

Etiology - Trauma, pressure, or metabolic disease.. affecting the enamel organ

Question 21

Enamel Pearl

Answer 21

-Apposition and Maturation stage
-Sphere of enamel root - almost perfectly round
-Etiology - displacement of ameloblasts to root surface

Question 22

Hypercementosis

Answer 22

-refers to excess deposition of cementum on the root surfaces
-a variety of local and systemic factors have been associated: trauma, inflammation, supraeruption, pituitary gigantism, arthritis, calcinosis, Paget’s disease, rheumatic fever, and goiter.

• Occurs predominately in adults and an increased frequency is seen with increasing age
• may cause concrescense

Question 23

Concrescence

Answer 23

• Apposition and Maturation Stage
• Union of the root structure of two or more teeth
  by cementum
• Commonly affects the permanent maxillary molars
• Etiology - traumatic injury or crowding of the
  teeth

Question 24

Root Formation

Answer 24

Dilaceration - results in a distorted root or severe crown angulation (caused by injury or pressure during tooth development)

• Flexion - a deviation or bend restricted just to the root
• Accessory roots - due to trauma, pressure or metabolic disease that effects HERS (Hertwig’s epithelial root sheath) during root developement

Question 25

Structural Anomalies

Answer 25

Resulting from disturbances in enamel and dentin formation - Apposition and Maturation Stages - Enamel or dentin dysplasia

Question 26

Enamel Dysplasia

Answer 26

-Results from a reduction in the quantity of the enamel matrix - Teeth appear with pitting and intrinsic colour changes in enamel

Question 27

Amelogeneis Imperfecta

Answer 27

* Type of enamel hypoplasia/dysplasia * Hereditary etiology * Can affect all teeth of both the primary and permanent dentitions * Teeth have very thin enamel that chips off or have no enamel at all – crowns are thus yellow * Varies in severity * Hereditary enamel hypoplasia is a type of amelogenesis imperfecta that is characterized by teeth with crowns that are hard and glossy, yellow, and cone-shaped or cylindrical

Question 28

Dental Fluorisis

Answer 28

* Dental fluorosis is a change in the appearance of the tooth's enamel. * These changes can vary from barely noticeable white spots in mild forms to staining and pitting in the more severe forms (enamel will be severely altered) * Dental fluorosis only occurs when younger children consume too much fluoride from any source over long periods when teeth are developing under the gums

Question 29

Turner's Teeth

Answer 29

* Hypoplasia of the enamel involving a single permanent tooth. * If found on a canine or a premolar, the most likely cause is an infection that was present when the primary tooth was still in the mouth. * If found in the anterior area of the mouth, the most likely cause is a traumatic injury to a primary tooth - occurs during formation of enamel

Question 30

Congenital Syphilis

Answer 30

* Hutchinson’s Incisors ◦ Abnormally shaped permanent front teeth (incisors) ◦ Usually associated with congenital syphilis (treponema palladium) * Mulberry Molars ◦ a first molar tooth whose occlusal surface is pitted due to congenital syphilis with nodules replacing the cusps

Question 31

Dentin Dysplasia

Answer 31

- faulty development of dentin

Question 32

Dentinogenesis Imperfecta

Answer 32

Hereditary basis - results in blue-gray or brown teeth with an opalescent sheen -enamel appears as usual but chips off due to lack of support from the abnormal underlying dentin - results in severe attitrion - teeth that have dentinogeneisis imperfecta are opalescent and have an almost amber colour

Question 33

Tetracycline Staining

Answer 33

- incorporation into dentinal tissue that is calcifying at the time of administration - the antibiotic become chemically bound to the dentin for the ife of the tooth and because of the transparency of enamel, it is visible - Permanent discoloration varies from yellow or gray to brown depending on the dose or the type of the drug received in ralation to body weight

Question 34

Odontoma

Answer 34

Etiology is unknown - tumor -local trauma -◦ Inflammatory and/or infectious processes ◦ Dental lamina remnants ◦ Hereditary anomalies ◦ Odontoblastic hyperactivity ◦ Alterations of the genetic component responsible for controlling dental development -usuaslly asymptomatic -often found when taking xrays

Question 35

Complex Odontomas

Answer 35

When the calcified dental tissues are simply arranged in an rregular mass bearing no morphologic similarity to rudimentary teeth (tumo)

Question 36

Compound odontomas

Answer 36

* Composed of all odontogenic tissues in an orderly pattern that results in many teethlike structures but without morphologic resemblance to normal teeth

Question 37

Ameloblastoma

Answer 37

◦ A tumor composed of remnants of the dental lamina

Question 38

Degeneration Changes - Attrition

Answer 38

* Wearing down of incisal/occlusal * Frictional contact * Grinding/occlusion

Question 39

Degeneration Changes - Abrasion

Answer 39

* Mechanical wearing away of tooth * Buccal/lingual surface * Recession * Toothbrush abrasion

Question 40

Degeneration Changes - Bruxism

Answer 40

◦ Oral habit consisting of involuntary gnashing, grinding, and clenching of the teeth in movements other than chewing ◦ Usually occurs during sleep and is commonly associated with stress or tension

Question 41

Degeneration Changes - Abfraction

Answer 41

* V – shaped notches in dentin * Confused with abrasion * Shear and tensile stresses * CEJ- slight flexion

Question 42

Degeneration Changes - Erosion

Answer 42

-Chemical wearing away -Disolving of enamel - bulemia -carbonated beverages -lemons

Question 43

Orofacial piercings

Answer 43

◦ Have become popular among some segments of the population ◦ Dental complications include chipped and broken teeth and serious infections at the sites of piercings ◦ Infection can spread throughout the head and neck area, with serious results

Question 44

Premature eruption

Answer 44

◦ In premature eruption, teeth are present at birth (natal teeth) ◦ Neonatal teeth are those that erupt within the first 30 days of life

Question 45

Ankylosis

Answer 45

- in decidous teeth affected by ankylosis, bone has fused to cementum and dentin, preventing exfoliation

Question 46

Impaction

Answer 46

Occurs when any tooth remains unerupted in the jaw beyond the time at which it should normally erupt