What are the 3 resounding characteristics of dental anomalies?
Absences
Excesses
Deformities
What are the four morphological stages of development of teeth?
•1. Bud Stage
•2. Cap Stage
•3. Bell Stage
•4. Root Development
What are the five Physiologic
Stages of Development of Teeth?
I. Initiation
II. Proliferation
III. Histodifferentiation
IV. Morphodifferentiation
V. Apposition
Characteristics of the "Initiation" stage...
Dental Lamina or Bud Stage
Affects the presence or absence
of tooth buds
Characteristics of the "Proliferation" stage...
Bud, Cap, Bell Stage
Affects size and proportions of
tooth
Characteristics of "Histodifferentiation" stage...
Advanced cap stage thru bell
stage
Involves formation of
enamel/dentin cells
Characteristics of "Morphodifferentiation" stage...
During bud, cap, bell stages
Shape and size of tooth affected
No effect on enamel/dentin
formation
Characterization of "Apposition" stage...
Bell stage thru completion of
root
What are some etiologies of dental anomalies?
A.Hereditary
B.Metabolic Disturbances
C. Developmental Disturbances
note: Permanent dentition most effected
rather than deciduous
In which stage of development do we see abnormal numbers of teeth (ie: anondontia & supernumerary teeth) develop?
Initiation stage.
Note: no buds in lamina (anondontia) or extra buds in lamina (supernumerary)
What is anondontia?
Lack of teeth.
True or false: In total anondontia, most primary teeth are present, but fewer permanent teeth develop.
True.
Characteristics of total anondontia?
Extremely rare, sex-linked genetic trait
An ectodermal defect, including hair and sweat glands
True or false: Partial anondontia prevents the initiation of tooth bids of affected teeth?
True.
note: partial anondontia is one or few missing teeth, caused by hereditary factors.
List in order the teeth that are most subject to anondontia.
a.Maxillary/Mandibular 3rd molars
b.Maxillary Lateral Incisors
c.Mandibular 2nd Premolar
d.Rare in deciduous teeth- Mandibular Central Incisors
What do "Mesiodens" and "Distodens" mean, respectively?
Mesiodens: supernumerary teeth between max central incisors
Distodens: supernumerary teeth distal to 3rd molars
True or False: Supernumerary teeth are not morphologically accurate.
False. The extra teeth are normal in morphological respects.
True or False: Supernumerary teeth are most common in the premolar area.
False. Supernumerary teeth are less likely in the premolar area. Mesiodens (between max and central incisors) and distodens (extras distal to 3rd molars) were emphasized in class.
If there's an abnormal size of teeth, in what stage is the disturbance most likely occuring?
Morphodifferentiation or bell stage
Which teeth most commonly exhibit macrodontia?
Incisors, canines, mand 3rds
Which teeth most commonly exhibit microdontia?
Max lateral incisors ("peg lateral") & max 3rd molars
If there's an abnormal shape of teeth, in what stage is the disturbance most likely occuring?
Morphodifferentiation and Appositional stages
What's the etiology of abnormally shaped teeth?
Hereditary or developmental disturbances like trauma or fever
What do we call the incomplete splitting of a single tooth germ (bifurcation of crown with single enlarged pulp chamber)? ... other than "totally jacked"...
"Gemination"
think: 2 crowns and a common root
What is "twinning"?
It's on the "gemination" continuum: if
splitting is complete, you have an extra tooth in the mouth. This is called TWINNING
When there's fusion of teeth, is enamel or dentin (or both) united?
Fusion: Two teeth united enamel and dentin.
Sometimes there is pulpal involvement as well.
*note: Unknown etiology- either hereditary or possible trauma resulting in pressure which closed the gap between 2 tooth buds
Usually involves anterior teeth
Results in one less tooth
What's this disorder called: "Join
when roots are in close proximity and excessive cementum deposition by one or both teeth"?
Concrescence: union of teeth by cementum.
True or false: "concrescence" occurs following eruption & usually involves permanent molars.
True.
"Taurodontism" sounds pretty daunting, eh? Yeah ... don't get too excited. Name some characteristics of this disorder.
Increase of crown at expense of root
Normal clinical and anatomic crown
Elongated body- enlarged pulp chamber without constriction of CEJ
Furcation and pulp chamber displaced apically which makes for a very short root
Results in increased dimension btwn CEJ and furcation
Hereditary
Affects Premolars and Molars
This disorder describes a severe bend or distortion of a tooth root and/or crown & results in a distortion of crown and root from normal linear relationship. Name our disorder.
DILACERATION.
note: Displacement of partially formed tooth and continued development in original position
What's the etiology of dilaceration?
traumatic injury
What's the disorder called when we see 'a tooth within a tooth'?
DENS IN DENTE
What's going on with the enamel organ, enamel, dentin, and lingual surface of the teeth in the anomalie "Dens in Dente"? Which teeth are most commonly affected by dens in dente?
Enamel organ becomes invaginated.
Normal enamel and dentin become reversed and form inside the tooth (pulp cavity)
Defect or pit at lingual surface of tooth
Typically permanent max lat incisors
One anomaly is a spherical nodule of enamel surrounding dentin attached to root surface of tooth, results form aberrant enamel deposition on the root, is usually found at the furcation of molars, and can prevent the normal connective tissue and consequently may cause perio issues. What is this anomalie?
ENAMEL PEARL
What's the difference between compound odontoma and complex odontoma? Remember that "odontoma" is the growth of calcified dental tissues, resulting from a disturbance in dental lamina by trauma or infection.
Compound Odontoma- calcified tissues of a tooth,
resembling a tooth
Complex Odontoma- mass of calcified dental
tissues without definitive dental form
When you see "screwdriver shaped teeth", of which anomaly do you think?
HUTCHINSON'S INCISORS.
Well... you may not have thought it, but that's the correct answer.
Notes on this anomalie:
Etiology- Prenatal Syphilis, Treponema organism disturbs calcification of enamel during tooth formation
Unusual incisor shapes
Screwdriver shaped teeth, broad cervically, and narrowing incisally
Notched incisal edge
Also recognized as "the posterior counterpart of Hutchinson's Incisor", this anomalie features a molar cusp that's more centrally located than a normal molar and enamel that's gnarled in appearance. What is our mystery anomaly?
MULBERRY MOLAR
Etiology: prenatal syphilis. (Dammit Mom!!)
What's the etiology of hypercementosis?
Trauma, metabolic dysfunction or chronic inflammation of the pulp
*other notes:
Involves roots of permanent molars
Occurs after eruption
In which stages/processes does "abnormal calcification" occur?
Histodifferentiation & Appositional processes
Notes:
Effects enamel and dentin formation
Etiology- hereditary, systemic or local factors
Name three enamel anomalies involving abnormal calcification.
Amelogenesis Imperfecta
Turner's Teeth
Fluorosis (mottled enamel)
Name two dentin-related abnormal calcification misfortunes.
Dentinogenesis Imperfecta
Tetracycline staining
Recite everything you know about "amelogenesis imperfecta".
If it was pretty quiet just then, try these five next time...
1. Hereditary
2. Ranges from complete absence
of enamel to enamel deposited, but not matured
3. Rampant caries
4. Excessive attrition
5. Esthetic concerns
What's the etiology of the enamel anomaly "Turner's Teeth"?
Trauma injury to developing tooth follicle by infection or extraction of deciduous tooth
Note: affects individual teeth
If we see a patient with "chalky white bands present on crown of tooth which become pigmented in a brown or yellow fashion…looks mottled", we should be dishing out a diagnosis of ...
FLUOROSIS.
*other notes:
Etiology- intake of excessively high levels of fluoride ion during the enamel calcification period
Resistant to caries due to etiology
Esthetic concerns
You notice in one of your patients a clinical
appearance of opalescent crown which is bluish-brown in color, obliterated pulp chamber, and normal enough looking enamel but fractures
easily due to lack of dentinal support. What diagnosis should you assign this person?
DENTINOGENESIS IMPERFECTA
*other notes:
Hereditary
Disturbance in dentin formation
What are some characteristics of tetracycline staining?
•1. Etiology- intake of tetracycline antibiotic either by mother during certain prenatal periods, or to infant
• 2. Causes intrinsic color change to the
dentin of teeth undergoing mineralization
• 3. Affects teeth that were undergoing
development at time of antibiotic therapy
• 4. Causes yellow or grayish cast on teeth affected
What are three anomalies related to injury after FULL development of teeth?
•Attrition
•Abrasion
•Erosion
What is attrition? What is it also called?
•Wearing away of enamel and dentin due to movement of mandibular teeth against maxillary teeth.
•Either from normal function or grinding, also called bruxism
What is abrasion? What common household item is usually the culprit?
Wearing away of tooth structureby mechanical means, usually a hard toothbrush
We see this anomaly commonly with patients who suffer from bulemia and also in patients who drink lots of carbonated drinks. One of our professors admitted to (inadvertently) doing this to himself by sucking on loads of lemons. When there's a lot of loss of tooth structure from chemical means, what is this called?
