variations Flashcards
3 factors affecting tooth development and eruption
- nutrition
- physical phenomenon
- infection
acquired variations in morphology
NOT genetically related
non-environmental variations
genetically related
wear mechanisms are
non-bacterial and not trauma
wear due to tooth-to-tooth contact
attrition
non-masticatory movements
abrasion
non-bacterial chemical action
erosion
flexural forces
abfraction
factors affecting attrition
- diet
- habits (gum, tobacco)
- malocclusion
condition involving attrition
bruxism
material detached from surface due to hard particles
abrasion
toothpaste is a
3 surface body
examples of abrasion
toothbrushing, pipe smoking
what is worse while toothbrushing
horizontal orientation and the actual tooth paste
wedge-shaped lesions with sharp internal and external line angles
abfraction
what causes abfraction
tensile stress from mastication and malocclusion
mechanism of abfraction
flexural forces disrupt enamel and dentin by cyclic fatigue, leading to cracks and chips (cervical area)
loss of a portion of a tooth
trauma
abnormal curvature of the crown or root, 45 deg to >90 deg
dilaceration or flexion
causes of dilaceration
- traumatic injury
- insufficient space for development
shortened roots with normal sized crown
dwarfed roots
excessive cementum around root
hypercementosis
causes of hypercementosis
- trauma
- attrition
- systemic diseases
- periapical inflammation
- perio
which teeth are most affected by hypercementosis
premolars
types of hypercementosis
- club shaped
- focal
- circular
submerged tooth (tooth erupted but failed to reach occlusion)
ankylosis
mechanism of ankylosis
infection of trauma to PDL, looses its PDL space, tooth fuses to alveolar bone
which tooth is most commonly affected by ankylosis
2nd deciduous molars
dens in dente (dens invaginatus)
invagination of enamel organ into crown
where does dens in dente occur commonly
max lateral incisors
risk of dens in dente
bacteria can easily penetrate pulp chamber
types of dens in dente
I: coronal third
II: middle third
II: root apex
fusion of two teeth at the roots only (via cementum)
concrescence
where is concrescence commonly observed
maxillary molar region
causes of accessory roots
- trauma
- metabolic dysfunction
- pressure
teeth with accessory roots usually
3rd molars
single rooted teeth that commonly have accessory roots
mandibular canines and premolars
teeth that dont erupt due to mechanical obstruction
impacted teeth
another name for supernumerary teeth
hyperdontia
if the supernumerary tooth is found at the midline of the max arch
mesiodens
if extra tooth is lingual or buccal to molars
paramolar
if extra tooth is distal to 3rd molar
distomolar
most common cause of impacted incisors
supernumerary teeth
large teeth
macrodontia
small teeth
microdontia
factors causing microdontia
- high dosage of drugs
- radiation
example of single microdontia
peg laterals
small teeth and large jaw
relative generalized microdontia
only small teeth
true generalized microdontia
most commonly affected by microdontia
max lateral incisor
3rd molars
peg laterals develop from
1 labial lobe (instead of 3)
down syndrome patients
- large deciduous
- small permanent (microdontia)
- higher prevalence of missing teeth
- fissure tongue
enlarged pulp chamber in posterior teeth (looks like a walking man)
taurodontia
what causes taurodontia
apical displacement of furcation area
splitting of a single tooth germ
germination or twinning
germination
single root and common pulp canal
union of tooth germs
fusion
count the tooth as one, there will be reduced # of teeth
fusion
count the tooth as one, there will be the same # of teeth
germination
odontogenic tumor
odontoma
