Question 1

Which term best describes a disorder caused by abnormalities in the genetic makeup transmitted from parent to offspring?

Accepted Answer

Inherited disorders are caused by abnormalities in the genetic makeup transmitted from parent to offspring. An anomaly is a marked deviation from normal that can be the result of congenital or hereditary defects. A congenital disorder is present at and existing from the time of birth. Developmental disorders occur when failure or disturbances occur during the complex series of cell division, multiplication, or differentiation.

Question 2

When two or more teeth are joined by cementum, as shown in this picture, it is termed

Accepted Answer

Concrescence occurs when two adjacent teeth are united by cementum. Dilaceration refers to an abnormal curve or angle in the root. Enamel pearl is a small spherical enamel projection located on a root surface. Gemination occurs when a single enamel organ (tooth germ) divides partially.

Question 3

During tooth development, ectoderm and ectomesenchymal cells give rise to each of the following except one. Which one is the exception?

Accepted Answer

The dental sac that surrounds the developing tooth germ provides cells that form the periodontal ligament. Ectoderm and ectomesenchymal cells give rise to ameloblasts. Ectoderm and ectomesenchymal cells give rise to odontoblasts. Ectoderm and ectomesenchymal cells give rise to cementoblasts.

Question 4

The radiographic image of this patient exhibits a biloculated, well-defined radiolucency lateral to the tooth root. It is asymptomatic. This is a _____ cyst.

Accepted Answer

A lateral periodontal cyst is named for its location. It presents as an asymptomatic radiolucency located on the lateral aspect of a tooth root. A residual cyst is a radicular cyst that remains after extraction of the offending tooth. A follicular cyst forms around the crown of an unerupted or developing tooth. A primordial cyst develops in place of a tooth.

Question 5

A solitary hypoplastic defect in this dentition is located on the facial surface of a permanent maxillary central incisor. The most likely cause of this defect is

Accepted Answer

Hypoplastic defects in a patient's dentition are indicative of physical injury of the primary teeth. A dietary deficiency during tooth formation would not typically appear in only one tooth. This description is not indicative of an absence of the primary mandibular central incisor. This description is not characteristic of neonatal hypoplasia of the primary anterior tooth.

Question 6

This patient exhibits an accessory cusp located in the cingulum of the maxillary right lateral permanent incisor. This can be diagnosed as a

Accepted Answer

A talon cusp is an accessory cusp located in the cingulum of a maxillary or mandibular permanent incisor. A dens in dente is a developmental anomaly that results when the enamel organ invaginates into the crown of a tooth before mineralization. Taurodontism is a term used to describe a developmental dental anomaly in which the teeth exhibit elongated, large pulp chambers and short roots. Dens evaginatus is an accessory enamel cusp found on the occlusal tooth surface.

Question 7

This patient is healthy with no history of local or systemic infection or disease. The patient's teeth are caries free, as are all of the teeth of all of the patients who exhibit this defect. This is characteristic of

Accepted Answer

Fluorosis occurs from ingestion of a high concentration of fluoride during tooth development. The teeth affected by fluorosis are generally decay resistant. Hutchinson incisors are a result of congenital syphilis. A Turner tooth is the result of infection from a deciduous tooth. Attrition is the result of the wearing away of tooth structure during mastication.

Question 8

Periapical radiographic examination reveals a well-defined unilocular radiolucency located in the midline of the hard palate. The diagnosis is _____ cyst.

Accepted Answer

A median palatine cyst is a well-defined unilocular radiolucency located in the midline of the hard palate. A nasolabial cyst is a soft tissue cyst with no alveolar bone involvement. A globulomaxillary cyst is a well-defined, pear-shaped radiolucency found between the roots of the maxillary lateral incisor and cuspid. A branchial cleft cyst is located on the lateral neck at the anterior border of the sternocleidomastoid muscle.

Question 9

Microdontia most commonly occurs in

Accepted Answer

Microdontia most commonly occurs in maxillary laterals and third molars. Microdontia does not commonly occur in the maxillary canine. Microdontia does not commonly occur in the mandibular molars. Microdontia does not commonly occur in the mandibular incisors and molars.

Question 10

Which tumor frequently arises from a dentigerous cyst?

Accepted Answer

An ameloblastoma frequently arises from a dentigerous cyst.

Question 11

The cyst that appears in the bone in this radiographic image surrounds the fully formed crown of an unerupted premolar. The dental hygienist should refer to this as a(n) _____ cyst.

Accepted Answer

A follicular cyst, also called a dentigerous cyst, appears in the bone in this radiograph surrounding a fully formed crown of an unerupted premolar. An eruption cyst is similar to a follicular cyst but is found in the soft tissue around the crown of an erupting tooth. A lateral periodontal cyst is seen most often in the mandibular cuspid and premolar area. It presents as an asymptomatic, unilocular or multilocular radiolucent lesion located on the lateral aspect of a tooth root. A primordial cyst develops in place of a tooth.

Question 12

A small elevated mass of thyroid tissue located near the foramen cecum or posterior lateral borders of the tongue, which forms as a result of failure of the embryonic thyroid tissue to migrate to its proper position, is called a(n)

Accepted Answer

A small elevated mass of thyroid tissue located near the foramen cecum or posterior lateral borders of the tongue, which forms as a result of failure of the embryonic thyroid tissue to migrate to its proper position, is a lingual thyroid nodule. An ameloblastic fibroma is a mixed odontogenic tumor. A hemangioma is a benign proliferation of capillaries. A thyroglossal duct cyst is located below the hyoid bone.

Question 13

Odontogenic keratocysts are a clinical component of

Accepted Answer

Odontogenic keratocysts are a clinical component of nevoid basal cell carcinoma syndrome.

Question 14

During embryonic development of the face, the frontal process divides into three parts. These three parts include the median nasal process, the right lateral nasal process, and the left lateral nasal process.

Accepted Answer

During embryonic development of the face, the frontal process divides into three parts. These three parts include the median nasal process, the right lateral nasal process, and the left lateral nasal process. Both statements are true.

Question 15

Deciduous teeth in which bone has fused to cementum and dentin, preventing exfoliation of the deciduous tooth and eruption of the underlying permanent tooth are termed

Accepted Answer

A tooth is ankylosed if it is fused to bone. This condition is especially common with retained deciduous teeth. Embedded teeth do not erupt because of a lack of eruptive force. Impacted teeth cannot erupt because of physical obstruction. Erupted teeth are not fused to cementum and dentin.

Question 16

The deformity seen here with a bend in root apices is characteristic of

Accepted Answer

Dilaceration refers to an abnormal curve or angle in the root. Gemination is when a single enamel organ (tooth germ) divides partially. Fusion is the union of two normally separated adjacent tooth germs. Concrescence is the union of two independently formed teeth by cementum.

Question 17

Odontogenesis in the human embryo takes place at approximately

Accepted Answer

Odontogenesis in the human embryo takes place at approximately 5 weeks. Odontogenesis in the human embryo takes place before 2 months. Odontogenesis in the human embryo takes place before 3 months. Odontogenesis in the human embryo takes place before birth.

Question 18

Proliferation is defined as

Accepted Answer

Proliferation is the multiplication of cells. Anodontia is the congenital lack of teeth. Dentinogenesis is the formation of dentin. Predilection is a disposition in favor of something; preference.

Question 19

This enlargement on the lateral neck of this patient has been present for months and is slowly increasing in size. It is painless and feels soft. Histologic examination shows this to be an epithelium-lined sac filled with clear, yellow fluid. It is a _____ cyst.

Accepted Answer

A thyroglossal duct cyst appears on the lateral neck and slowly increases in size. It is painless and feels soft. Histologic examination shows an epithelium-lined sac filled with clear, yellow fluid. A branchial cleft cyst is located on the lateral neck at the anterior border of the sternocleidomastoid muscle. A median palatine cyst is a well-defined unilocular radiolucency located in the midline of the hard palate. A globulomaxillary cyst is a well-defined, pear-shaped radiolucency found between the roots of a maxillary lateral incisor and cuspid.

Question 20

When counting the maxillary anterior teeth of this adolescent patient, it appears that five are present clinically, if the large tooth is counted as one. A radiographic image reveals that this large central tooth has two roots. This tooth demonstrates

Accepted Answer

Fusion is the union of two normally separated adjacent tooth germs. Gemination is when a single enamel organ (tooth germ) divides partially. Concrescence occurs when two adjacent teeth are united by cementum. Dilaceration refers to an abnormal curve or angle in the root.

Quiz 5: Developmental Disorders