Developmental Disturbances of Teeth (pt1)

Question 1

What are the stages involved in odontogenesis

Answer 1

1) Initial stage - dental lamina arise from primary epithelial tissue, dental placode arise from dental lamina

2) Bud stage - formation of tooth bud, ectomesenchyme cells proliferate the jaw

3) Cap stage - “proliferation stage” placode enters bud, formation of enamel organ

4) Early bell stage - histodifferentiation (amelo & odontoblast obtain phenotype) & morphodifferenation (crown forms its shape)

5) Late bell stage - (initiation of mineralization, development of cusp & root)

6) Eruption (dental tissue fully mineralize to mature form)

Question 2

What are the 3 processes that occur simultaneously during tooth development & give their roles?

Answer 2

1) Cellular proliferation - cells multiply, inc in number
2) Histodifferentiation - cells change function (ameloblast & odontoblast obtain phenotype)
3) Morphodifferentian - cells change shape (flat-round)

Question 3

Give the parts & roles of the tooth germ

Answer 3

Enamel organ: ameloblast that gives rise to the enamel, secretes & synthesis enamel specific proteins

Dental Papilla: odontoblast give rise to dentin & pulp that serve as natural barriers, detect caries related pathogens & sense external irritations

Dental Folicle: give rise GCAP gingiva, cementum, alveolar bone & periodontal ligament that is comprise of the periodontium a supportive tissue

Question 4

What happens when disturbances occur during tooth development?

Answer 4

Dental anomalies can occur based on the affected structure and point of odontogenesis that can be due to intrinsic (congenital, hereditary) or extrinsic factors (medication, alcohol, vax, drug exposure during pregnancy, infection)

Question 5

Outline the developmental disturbances of teeth.

Answer 5

I. Alteration in Size: Microdontia & Macrodontia
II. Alteration in Number & Eruption: Supernumerary, Anodontia, Impacted
III. Alteration in Shape (Crown: GFTTDDMPH; Root: FACED)
IV. Alteration in Enamel & Dentin (Enamel: LEA; Detin: DD)

Question 6

Differentiate microdontia & macrodontia

Answer 6

Microdontia is the appearance of smaller teeth size than normal with etiology that is due to disturbance during odontogenesis & associated with inheritance pattern and genetics. It occurs in the MAXILLARY LATERAL INCISOR with peg shape or cone-shaped laterals.

Macrodontia is the appearance of larger teeth size than normal with unknown etiology; its appearance is an enlarged tooth crown with distorted morphology resembling germination or fusion in the MANDIBULAR 3RD MOLAR

Question 7

Give the etiology of microdontia & management.

Answer 7

Microdontia is due to disturbances during odontogenesis and is associated with inheritance pattern & genetics

Management:
1) conservative (esthetic/resto trt)
2) long term comprehensive interdisciplinary
approach (resto, ortho, surgical & prosthetic trt)

Question 8

Differentiate or give the clinical features of microdontia

Answer 8

Generalized microdontia: all teeth are smaller than normal size, associated w pituitary dwarfism;

Focal microdontia: few or selected teeth are smaller in size, with a peg or cone-shaped crown occurring in the maxillary lateral incisor

Disproportional microdontia: relatively generalized, px has big jaw with normal size of teeth that gives disproportion apperance

Question 9

Give the description & clinical presentation of macrodontia

Answer 9

Macrodontia is the appearance of larger teeth size than normal tooth
Etiology is unknown
Clinical features enlargement of the crown & distorted morphology resembling germination or fusion, commonly seen MANDIBULAR 3RD MOLAR

Question 10

Give the tooths where macrodontia & microdontia occurs

Answer 10

Macrodontia: Mandibular 3rd molar
Microdontia: Maxillary Lateral Incisor

Question 11

Outline the alteration in number & eruptions of tooth

Answer 11

I. Supernumerary
II. Anodontia
III. Impacted

Question 12

Give the clinical significance of supernumerary

Answer 12

OWDM

1) Occupy space
2) When impacted, block eruption of the tooth
3) Delayed eruption of the adjacent tooth
4) Malalignment of dentition

Question 13

Describe supernumerary & management

Answer 13

It is known as an extra tooth due to the continued proliferation of the dental papilla that forms a 3rd tooth germ; Management; extraction or repositioning of dental arch

Question 14

Outline the common sites of supernumerary

Answer 14

M4PMPT
1) Mesiodens - in between the central incisor, give rise to diastema
2) Maxillary 4th premolar or molar
3) Periodens - outside dental arch
4) Mesio/Distomolar - molar region
5) Paramolar - buccal, lingual, or proximal to molars
6) Paramolar tubule - fused w permanent molar

Question 15

Describe & give etiology of the occurrence of anodontia

Answer 15

Anodontia is the absence of teeth, a rare dental anomaly that can occur in both primary & permanent dentition; It is caused by the failure of tooth bud to develoop

Question 16

Outline the frequency of missing teeth

Answer 16

32LCL
1) 3rd molar
2) Mandibular 2nd premolar
3) Maxillary lateral incisor
4) Mandibular central incisor
5) Mandibular lateral incisor

Question 17

Give the clinical significance of anodontia or failure of eruption of permanent teeth

Answer 17

LOSR
1) Loss of space
2) Overcrowding
3) Supernumerary or supplemental teeth
4) Retention of the deciduous predecessor

Question 18

Outline the types & subtypes of anodontia

Answer 18

I. Complete Anodontia - all teeth are missing
II. Partial Anodontia - a few or some teeth are missing
(A) Hypodontia - less than six teeth are missing
(B) Oligodontia - 6 or more teeth are missing

Question 19

Describe & give the etiology of impaction

Answer 19

Impacted teeth is defined as tooths that are prevented from eruption due to physical blockage in the eruption path

It is caused by OAUA
- obstruction of physical barrier
- abnormal eruption path
- unusual orientation of tooth germ
- ankylosis

Question 20

Outline the classification for impacted teeth

Answer 20

Class 1 - there is enough or adequate space between the ramus & distal of the 2nd molar, and there is enough space to accommodate the mesiodistal crown of the 3rd molar

Class 2 - space between the ramus & distal of the 2nd molar is less than the mesiodistal space of the crown of the 3rd molar.

Class 3 - impacted teeth is completelt located in the ramus, present the greatest difficulty and least accessibility

Question 21

Outline the impacted teeth based on relative depth in bone

Answer 21

I. Position A - impacted teeth is in level with or above the occlusal plane of the 2nd molar

II. Position B - impacted teeth is below occlusal plane and above the cervical line of the 2nd molar

III. Position C - impacted teeth is below the cervical line of 2nd molar

Question 22

Give winter’s classification of impaction

Answer 22

MILD BVH
1) Mesioangular Impaction
2) Inverted Impaction
3) Linguoangular Impaction
4) Distoangular Impaction
5) Buccoangular Impaction
6) Vertical Impaction
7) Horizontal Impaction

Question 23

Clinical presentation or tooths involved in impaction

Answer 23

Maxillary canine, Mandibular 3rd molar