Tooth Development

• The correct developmental sequence involves differentiation of odontoblasts, elongation of enamel epithelium, dentine formation, and then enamel formation. [Q0015]
• Oligodontia occurs during the initiation and proliferation stages of tooth development, resulting in the absence of six or more teeth excluding third molars. [Q0064]
• The correct sequence starts with initiation, followed by proliferation, histodifferentiation, morphodifferentiation, and mineralization. This sequence ensures proper tooth development. [Q0065]
• At birth, the crowns of all deciduous teeth and the first permanent molars are partially calcified, providing a foundation for further dental development postnatally. [Q0095]
• The growth of alveolar bone is primarily stimulated by the eruption of teeth, which is critical for maintaining bone volume and health. [Q0390]
• The differentiation of the tooth bud takes place during the bell stage, which is crucial for the formation of the future shape and size of the tooth. [Q3316]
• The bud stage begins in the first trimester of pregnancy, marking the initial phase of tooth development where tooth germs form. [Q3390]
• The cap stage of tooth development begins at the 8th week of gestation, where the enamel organ starts to take shape. [Q3407]
• Dentine formation always precedes enamel formation, as dentine provides the necessary support and foundation for enamel deposition. [Q3584]
• Cells for enamel and dentine come from the dental papilla, which differentiates into odontoblasts and ameloblasts. [Q3669]
• The dental lamina is the first structure to form in the development of a tooth, giving rise to tooth buds. [Q3729]
• Teeth germs develop from the dental lamina, a band of epithelial tissue crucial for initiating tooth development. [Q4884]
• Yes, the dental lamina is derived from the epithelial band, initiating the formation of tooth germs. [Q4973]
• Enamel is derived from the ectoderm, specifically from the enamel organ’s inner enamel epithelium. [Q4996]
• Enamel is derived from ameloblasts, which originate from the inner enamel epithelium of the enamel organ. [Q5848]
• The stellate reticulum forms the bulk of the enamel organ and consists of star-shaped cells, providing support to the developing enamel. [Q6046]

Developmental Anomalies

• Mandibular second premolars (35, 45) are commonly congenitally missing teeth, often associated with genetic and environmental factors during tooth development. [Q0244]
• Carabelli cusps are less common in Negros, indicating a genetic variation in dental morphology among different populations. [Q3534]
• The cusplet of Carabelli is typically not found in deciduous upper molars but in permanent upper molars, indicating a developmental difference. [Q4965]
• Isolated cleft palate is more common in females due to delayed palatal shelf fusion, which increases the risk of incomplete closure. [Q6102]

Craniofacial Development

• No, only some bones originate from cartilage, while others form directly from mesenchymal tissue through a process known as intramembranous ossification. [Q3210]
• The foramen caecum is the primordial site for the development of the thyroid gland, which descends into the neck from this location. [Q3761]
• Fusion of the palatal processes is complete by the end of the twelfth week of development, ensuring the separation of the oral and nasal cavities. [Q3797]
• Epithelial cells become trapped between the palatal shelves during embryonic development, potentially leading to cyst formation. [Q5682]
• The secondary palate forms during the ninth to twelfth week of embryonic development, completing the separation of the oral and nasal cavities. [Q5826]
• Dentin and pulp are derived from neural crest cells, which migrate and differentiate into various dental tissues. [Q5847]
• The tongue is derived from the first, second, and third pharyngeal arches, contributing to its complex structure. [Q6036]

Genetics and Birth Defects

• Amelogenesis imperfecta can be an autosomal trait, affecting enamel formation due to genetic mutations. [Q3231]
• Amelogenesis imperfecta can be caused by a mutation in the AMEL X gene, which encodes for amelogenin, a protein critical for enamel development. [Q3232]
• Anhidrotic ectodermal dysplasia is a hereditary disease characterized by abnormal development of skin, hair, nails, teeth, and sweat glands. [Q3270]
• Anhidrotic ectodermal dysplasia is a sex-linked recessive trait, typically affecting males and passed through the X chromosome. [Q3273]
• Dentinogenesis imperfecta is a defect in type I collagen, leading to discolored, weak, and brittle teeth. [Q3587]
• Down Syndrome is caused by a trisomy of chromosome 21, leading to developmental delays and distinct facial characteristics. [Q3620]
• Down syndrome is not directly associated with a single gene mutation but with an extra copy of chromosome 21, affecting multiple genes. [Q3623]
• Edwards syndrome is associated with trisomy 18, causing severe developmental delays and health issues. [Q3652]
• Chromosome 4q21 contains the gene for enamelin, which is implicated in amelogenesis imperfecta, affecting enamel formation. [Q4954]