Term
| -List the two types of Anodontia/Hypodontia. -List the disease most commonly associated. -List the 3 most commonly missing teeth. |
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Definition
| -true or acquired. -ectodermal dysplasia. -3rd molars > Md 2nd PM > MX laterals. |
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Term
| Supernumery teeth: (1) where do they occur? (2) most common locations. (3) associated disease. (4) describe disease. |
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Definition
| (1) ~90% in Mx. (2) mesiodens, between Mx centrals. (3) Gardner syndrome. (4) osteomas of the b ones, multiple epidermoid cysts of the skin, desmoid tumors, multiple polyposis of the colon. |
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Term
| Amelogenesis Imperfecta: (1) 3 classifications. (2) describe each. (3) list example of each |
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Definition
| (1) Hypoplastic - enamel not full thickness on newly erupted teeth. (2) Hypocalcified - enamel can be removed with prophylaxis instruments. (3) Hypomaturation - pierced by explorer point with firm pressure. |
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Term
| Dentinogenesis Imperfecta: (1) aka. (2) visual description. (3) clinical significance. (4) List types. (5) Radiographic presentation. (6) Composition difference. |
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Definition
| (1) hereditary opalescent dentin. (2) unusual translucency from grey to brownish violet or yellowish brown. (3) enamel chips off easily. (4) Types I-III. (5) Total or partial obliteration of pulp chambers and pulp canals. (6) Dentin matrix is poorly organized, poorly calcified and has a higher water content. |
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Term
| Dentin Dysplasia: (1) description. (2) Types. (3) Clinical signs. (4) Radiographic presentation. |
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Definition
| (1) Disturbance characterized by normal enamel but atypical dentin and pulp morphology. (2) I - Radicular dentin dysplasia - extremely mobility, extremely short root; II - Coronal dentin dysplasia - similar to detinogenesis imperfecta. |
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Term
| Regional odontodysplasia: (1) aka. (2) description. (3) location. (4) radiographic presentation. (5) proposed etiology. |
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Definition
| (1) ghost teeth. (2) teeth in localized area show either delayed or total failure in eruption. (3) Mx anteriors. (4) teeth present a ghost-like appearance. (5) some sort of vascular defect. |
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Term
| Odontogenesis is traditionally broken into morphologic development stages as: |
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Definition
| oral ectoderm--> dental lamina--> bud--> cap--> bell |
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Term
| Odontogenesis is broken into physiologic stages as: |
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Definition
Initiation
Proliferation
Morphodifferentiation
Histodifferentiation
Apposition and Minerialization
Eruption
Attrition |
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Term
| Initiation - list the physiologic stages accompanying this stage: |
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Definition
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Term
| Proliferation - list the physiologic stages accompanying this stage: |
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Definition
| Dental lamina, bud stage, cap stage, bell stage. |
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Term
| Dental lamina: List two proliferation facts about this stage. |
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Definition
(a) earliest sign seen in 5-6 week embryo
(b) appears as slight thickening of oral ectoderm over the ridge. |
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Term
| Bud stage: List two proliferation facts about this stage. |
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Definition
(a) small fingers of dental lamina invade underlying connective tissue.
(b) this initially happens at ten locations on the maxilla and ten locations on the mandible (corresponds to the 20 primary teeth). |
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Term
| Cap stage: List two proliferation facts about this stage. |
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Definition
(a) the epithelial bud proliferates to assume the shape of a cap.
(b) the mesenchymal tissue within the concavity of the "cap" becomes more cellular and dense. |
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Term
| Bell stage: List two proliferation facts about this stage. |
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Definition
(a) the epithelium proliferates to the final form of the enamel organ.
(b) the mesenchymal tissue becomes more cellular and vascular to form the dental papilla. |
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Term
| Morphodifferentiation - list the physiologic stages accompanying this stage: |
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Definition
| bud stage, cap stage, bell stage. |
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Term
| Bud stage: List one morphodifferentiation fact about this stage. |
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Definition
| the epithelium migrates into the underlying connective tissue to location where the tooth bud will form. |
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Term
| Cap stage: List one morphodifferentiation fact about this stage. |
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Definition
| The forming tooth bud begins to take on the rough outline of the crown. |
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Term
| Bell stage: List three morphodifferentiation facts about this stage. |
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Definition
(a) the final form of the enamel organ
(b) this stage is the most miportant in morphodifferentiation of the tooth crown.
(c) the junction between the inner enamel epithelium and the odontoblasts determine where the dentinoenamel junction is and therefore the final form of the tooth crown. |
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Term
| Histodifferentiation - list the physiologic stages accompanying this stage: |
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Definition
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Term
| Cap stage: List two histodifferentiation facts about this stage. |
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Definition
(a) formation of the inner and outer enamel epithelium, stellate reticulum from the epithelial component.
(b) formation of the dental papilla and dental sac from the mesenchymal tissue. |
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Term
| Bell stage: List three histodifferentiation facts about this stage. |
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Definition
(a) formation of ameloblasts from inner enamel epithelium.
(b) formation of stratum intermedium between inner enamel epithelium and stellate reticulum.
(c) formation of odontoblasts in response to enamel epithelium. |
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Term
| Apposition and mineralization: List two facts for dental and three facts for enamel. |
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Definition
Dentin:
(a) dentin is formed first by the odontoblasts that formed in response to the inner enamel epithelium.
(b) the dentinal matrix is formed by the odontoblasts and is then mineralized.
Enamel:
(a) enamel can only form after dentin has been laid down.
(b) enamel will only form where there is stratum intermedium present.
(c) enamel matrix is formed by ameloblasts and then calcifies. |
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Term
| Define Hertwig's epithelial root sheath. What do the remnants persist as? |
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Definition
The skirt of epithelium at the bottom edge of enamel organ where the outer and inner enamel epithelium come together without intervening stellate reticulum or stratum intermedium.
Epithelial rests of Malassez. |
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Term
| Does enamel form in the root? Why/why not? |
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Definition
| No. Lack of stratum intermedium and stellate reticulum. |
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Term
| Does dentin form in the root? Why/why not? |
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Definition
| Yes. Presence of inner enamel epithelium does cause odontoblasts and dentin to form. |
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Term
| Define epithelial diaphragm. |
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Definition
| The end of Hertwig's root sheath that bends inward on a horizontal plane and determines the shape of the developing root. |
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Term
| Explain what happens to the Hertwig's root sheath as the root increases in length. |
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Definition
| Hertwig's root sheath is broken up by the surrounding fibrous connective tisue that is to become the periodontal ligament. |
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Term
| What does the periodontal ligament form? |
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Definition
| cementoblasts that lay down cementum. |
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Term
| Microdontia. List and explain the classification. List most common teeth affected. |
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Definition
Can be classified as localized or generalized (relative or true).
In relative microdontia the teeth are in the normal range but appear small relative to a larger jaw. In true microdontia (a rare condition) all the teeth are actually smaller than normal.
Microdontia involving single teeth commonly affect maxillary laterals and third molars. The common form is the "peg lateral." This laterals have a cone shaped crown. |
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Term
| Macrodontia. List and explain the classification. |
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Definition
True generalized (rare)
Relative generalized (common)
Macrodontia of single teeth (rare and must not be clinically confused with fusion). |
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Term
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Definition
| an anomaly resulting in incomplete formation of two teeth from a single tooth germ secondary to incomplete division of the tooth germ. Most often the tooth has two completely or incompletely separated crown sharing a single root and root canal. |
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Term
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Definition
| The union of two normally separated teeth and may be complete or incomplete. The dentin of the two teeth must be joined between the two teeth in true fusion. The differentiation between fusion and gemination may be difficult if a supernumerary tooth is involved. The root canals are often separate. |
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Term
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Definition
| Teeth that are united to each other by cementum after root formation is complete. There is no fusion of dentin in concrescence as there is in true fusion. It is very important clincially to determine if concrescence is present, especially prior to attempted extraction of the involved teeth. |
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Term
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Definition
| Sharp angulation of the tooth root. It is believed to be due to trauma and displacement of the tooth bud during root formation. This displacement of the permanent tooth bud may follow traumatic injury to the deciduous tooth where this preceding tooth is driven apically. This malformation may make extraction of the affected tooth difficult if not diagnosed prior to surgery. |
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Term
| Supernumerary roots. Which teeth most affected? |
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Definition
| Not uncommon. Third molars most commonly affected. Also seen on mandibular cuspids and mandibular bicuspids. More rarely other teeth may be affected. |
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Term
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Definition
| An anomalous structure that appears to be a markedly enlarged cingulum shaped like an eagle's claw on the lingual of permanent incisors. It extends from the cingulum area incisally, often to the incisal edge of the affected tooth. They may cause problems with occlusion. |
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Term
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Definition
| Anomaly appearing as a globule of enamel or an extra cusp between the buccal and lingual cusps of bicuspids. It is seen in oriental and may cause pulp exposure due to occlusal wear. |
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Term
| Dens in dente. Aka. Teeth most commonly affected. Common problems associated with it. |
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Definition
Anomaly due to invagination of the enamel epithelium in the lingual pit areas of incisors before calcification occurs. dens invaginatus.
The teeth most commonly affected are the maxillary laterals. Bilateral affliction is common. It may present as just an accentuation of the lingual pit to severe cases where there almost appears to be a "tooth within a tooth." This accentuation of the lingual pit often leads to caries and a necrotic pulp that can be difficult to treat endodontically. |
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Term
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Definition
A small focal excrescence of enamel most commonly found at or near the bifurcation or trifurcation of the roots of molar teeth.
Enameloma.
They are almost eight times as common on maxillary molars than mandibular molars. Although these lesions are seldom of clinical significance, they can complicate periodtonal tretment and may be mistaken for calculus. |
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Term
| Taurodontism. Explain a possible developmental cause. Which syndrome is it connected with? |
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Definition
A dental anomaly where the roots of molar teeth do not bifurcate or trifurcate at the normal level. The furcation takes place at a more apical level and looks similar to the teeth of cud-chewing animals (bulls).
This may be due to failure of Hertwig's root sheath to invaginate at the proper level. It has been reported that it is not uncommon for individuals with Klinefelter syndrome (extra X chromo) to have taurodontism.
The pulp chamber is very large and can extend down to within a few mm of the apices. |
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