Chapter 16 Flashcards
The three divisions of the dentitions are
the primary (deciduous) dentition, mixed (transitional) dentition, and permanent dentition.
The formation of the primary teeth begins
in utero.
Mixed or transitional dentition occurs between the ages of
6 and 12 years when primary teeth are being exfoliated and permanent teeth erupt.
Succedaneous teeth are
permanent teeth that erupt into the positions of exfoliated primary teeth.
The permanent dentition consists of ___teeth that replace the ____ and serve throughout life.
32; primary teeth
Mineralization of the permanent teeth starts at
“birth” and continues into adolescence.
Roots are completely formed about___
3 years after eruption into the oral cavity.
Clinical crown is the part of the tooth____. It can be considered the part of the tooth that is____
above the attached periodontal tissues; visible (not covered with gingiva) when in the mouth and where restorative treatment procedures are performed
Clinical root is the part of the tooth______ It is the part of the root to which_____ are attached.
not visible because it is below the base of the gingival sulcus or periodontal pocket (is not visible when in the mouth); periodontal fibers
______is the part of the tooth covered by enamel.
Anatomic crown
___is the part of the tooth covered by cementum.
Anatomic root
The hard tissue examination includes
Dental charting of the existing restorations
Assessment of carious lesions and noncarious lesions.
Occlusion
Preparation of study models to aid with treatment planning
During the dental charting of existing restorations procedure of the hard tissues exam, what is completed?
Charting of missing, supernumerary, unerupted teeth, and existing restorations
What are the three types of examination when assessing noncarious and carious lesions during the hard tissues exam?
Visual examination, radiographic examination and clinical examination
What is the visual examination procedure for assessing noncarious and carious lesions?
1.use air to clean and dry tooth surface
- utilize adequate lighting.
- Carefully visually inspect each surface. Transillumination is especially useful for anterior teeth and unrestored posterior teeth.
- Observe changes in the color and translucency of tooth structure
- Changes noted can then be studied in the radiograph or documented for future review.
(Radiology powerpoint: can also use dental instruments like explorers)
What is the radiographic examination procedure for assessing noncarious and carious lesions?
- Carefully review and interpret radiographic findings to identify areas to investigate during the clinical examination. For example: possible caries lesions, anomalies, impactions, fractures, internal and root resorption, and periapical radiolucencies.
What is the clinical examination procedure for assessing noncarious and carious lesions?
- If caries cannot be confirmed visually or radiographically, gently use a rounded or ball-end explorer to confirm visual findings.
- Use this time to record intraoral images. They can also document the existing oral condition and provide visual representation of treatment needs both for documentation in the patient record and to educate the patient.
What should be documented after finishing the assessment for noncarious and carious lesions part of the hard tissues exam?
Existing restorations.
Developmental enamel lesions.
Noncarious cervical lesions (NCCLs).
Carious lesions using a recognized classification system
Any other pathology noted during the radiographic or clinical examination.
For the occlusion part of the hard tissues exam, assessment of occlusion will include:
Normal occlusion.
Malocclusion.
Malrelations of groups of teeth.
Malpositions of individual teeth.
Dynamic (or functional) occlusion.
Traumatic occlusion.
What is the purpose of study models in the hard tissues exam?
To assess and document occlusal relationships
Prepare for treatment
Name some developmental enamel lesions
Enamel hypoplasia, hypomineralization/hypocalcification, and hypomaturation
What is enamel hypoplasia?
incomplete or defective formation of the enamel of either primary or permanent teeth
What are the three types of etiology that can cause enamel hypoplasia?
Genetic, systemic conditions, and local injury to developing tooth
Give some example of enamel hypoplasia caused by genetics during tooth development
Amelogenesis imperfecta is a hereditary enamel defect in which the enamel is either thin or absent. The enamel may also have surface pitting or vertical grooves.
• Other inherited syndromes associated with enamel defects may be associated with dermatologic conditions or defects in mineralization such as hypoparathyroidism.
Give some example of enamel hypoplasia caused by systemic conditions during tooth development
• Metabolic disturbancessuch as celiac disease and chronic renal or liver disease.
• Infections causing fever such as chicken pox, rubella, measles, or congenital syphilis.
• Chemicals and drugs such as fluoride and tetracycline.
• Nutritional deficiencies like rickets and hypocalcemia
• Preterm birth
Give some examples of enamel hypoplasia caused by local insults to developing tooth
• Trauma.
• Periapical infections and inflammation of a primary tooth may injure the developing permanent tooth.
What is the appearance of enamel hypoplasia? Include appearance when caused systemically and congenital syphillis
The teeth may appear yellow or brown, enamel may be thin, have many pits or grooves or may not be present in some part of the tooth
Local enamel hypoplasia: A single tooth with a yellow or brown intrinsic stain.
Systemic enamel hypoplasia
• Also called chronologic hypoplasia because the lesions are found in areas of the teeth where the enamel was forming during the systemic disturbance
- Single narrow zone (smooth or pitted): Disturbance lasted a short period of time.
2.Multiple (may appear as furrows or horizontal rows of dimples in the enamel): Disturbance to the ameloblast occurred over a period of time or several times
Hypoplasia of congenital syphilis
- the mulberry molar
- Hutchinson’s incisors**
- peg lateral incisor
What is hypomineralization?
Deficiency in mineralization of the tooth enamel
Hypomineralization occurs during the
maturation stage of enamel mineralization
Hypomineralization may result in a higher risk for
hypersensitivity, tooth wear, and dental caries.
What is the etiology for hypomineralization?
Systemic disturbances like
- celiac disease (causes mineral deficiencies)
- chronic liver or kidney disease
- childhood illness associated with a high fever
- Chemicals and drugs such as fluoride and tetracycline.
What are the types of hypomineralization?
Molar incisor hypomineralization (MIH)
appears as yellow or brownish demarcated areas on one or more permanent molars and incisors. Occasionally the defects may involve the primary second molars along with the permanent canines and premolars.
Amelogenesis imperfecta: In the hypomineralized type, enamel is a normal thickness, but opaque and brittle.
Dental fluorosis : Exposure of the enamel organ to excessive fluoride during development. Severe forms appear yellow/brown and the enamel is prone to breakdown.
Hypomaturation occurs during
the last stages of mineralization from a decrease in deposition of mineral.
In hypomaturation, The enamel may appear
opaque or discolored and fracture easily.
What are the genetic reasons for developmental defects of dentin?
Current genetic evidence suggests there is just one gene responsible for disturbances in dentin development with a range of severity.
• Dentinogenesis imperfecta (DI)
characteristics vary from mild to severe.
Milder forms were previously named dentin dysplasia.
Mild-severity Dentinogenesis imperfecta characteristics:
• Normal to light gray discoloration of the crown.
• Pulp chamber may be thistle-shaped.
In moderate to severe Dentinogenesis imperfecta characteristics:
• Crowns may be blue, gray, or brown opalescent in color.
• Shortened, bulbous tooth
crowns.
• Alterations in the pulp from complete obliteration to an enlarged pulp.
• Thin and shortened roots.
• Increased incidence of periapical pathology.
More severe DI may be associated with more fragile bones (osteogenesis imperfecta).
Give some examples of noncarious dental lesions
Attrition and erosion
What is attrition?
Attrition is the wearing away of a tooth as a result of tooth-to-tooth contact
What is the occurrence of attrition?
Location
• May be found on occlusal or incisal, and proximal surfaces.
Impact of age and gender
• Effects of attrition are cumulative over time, so an increase in attrition is often associated with increasing age.
What is the etiology of attrition?
- Bruxism
- Occlusal interferences
- Modifying factors such as Ecstasy use causing bruxism, habit of chewing on hard foods like bones., SSRIs (selective serotonin uptake inhibitors) used as an antidepressant may cause bruxism.
What is the appearance of attrition?
Initial lesion
• Small shiny, flat, worn spot on the surface of a tooth known as a facet is found on a cusp tip or ridge, or slight flattening of an incisal edge.
Advanced
Gradual reduction in cusp height
Flattening of incisal or occlusal plane
Staining of exposed dentin.
Radiographically the pulp chamber and canals may be narrowed and sometimes obliterated as a result of formation of secondary dentin.
What is erosion?
Erosion is the loss of tooth substance by a chemical process that does not involve known bacterial action.
What is the location of erosion?
Facial or lingual surfaces of multiple teeth are mostly commonly affected.
What is the etiology of erosion?
Erosion can result from endogenous and exogenous acid sources.
What is the process of erosion?
• Exposure to acid causes loss of the outermost enamel and dentin and softening (demineralization) of the tooth surface.
• This softened surface is easily removed by mechanical forces, such as toothbrushing.
What is the appearance of erosion of enamel?
• Smooth, shallow, hard, shiny (in contrast to dental caries, in which appearance is soft and discolored).
• Shape varies from shallow saucer-like depressions of the cusps to deep wedge-shaped grooves; margins are not sharply demarcated
• May progress to involve the dentin and stimulate secondary dentin.
What are non carious cervical lesions?
NCCLs are lesions resulting from loss of tooth structure near the
cementoenamel junction not related to dental caries.
The lesions typically are wedge-shaped and at least 1 mm deep; near the
cementoenamel junction not related to dental caries.
Noncarious cervical lesions
Danger of NCCLs?
They impact the structural integrity of the tooth and esthetics
May retain dental biofilm
Cause dentin hypersensitivity.
What are two types of NCCLs?
Abrasion and abfraction