DANBs Orthodontic Assisting OA

DANBs Orthodontic Assisting (OA) Exam

Question 1. Which craniofacial bone is primarily involved in forming the palate and the nasal cavity floor?

• Maxilla
• Palatine
• Ethmoid
• Vomer

Answer: A

Explanation: The maxilla is the main bone forming the upper jaw, palate,

and part of the nasal cavity floor, playing a crucial role in craniofacial structure and occlusion.

Question 2. Which muscle is primarily responsible for elevating the mandible during mastication?

• Temporalis
• Masseter
• Medial pterygoid
• Lateral pterygoid 1 / 4

DANBs Orthodontic Assisting (OA) Exam

Answer: B

Explanation: The masseter muscle is a powerful elevator of the

mandible, essential for biting and chewing functions.

Question 3. The temporomandibular joint (TMJ) is classified as which type of synovial joint?

• Hinge joint
• Condyloid joint
• Plane joint
• Ball-and-socket joint

Answer: B

Explanation: The TMJ is a condyloid joint allowing movement in multiple

planes, including opening, closing, and lateral excursions.

Question 4. Which of the following describes Angle's Class I occlusion?

• Molar relationship where mesiobuccal cusp of maxillary first molar 2 / 4

DANBs Orthodontic Assisting (OA) Exam

aligns with the mesiobuccal groove of mandibular first molar

• Molar relationship where maxillary molar is distal to mandibular

molar

• Molar relationship where mandibular first molar is advanced

anteriorly

• Molar relationship with crossbite

Answer: A

Explanation: Class I occlusion is characterized by a normal molar

relationship where the maxillary first molar's mesiobuccal cusp aligns with the mandibular first molar's mesiobuccal groove.

Question 5. Which environmental factor is most associated with the development of malocclusion?

• Genetic mutations
• Thumb sucking
• Craniosynostosis
• Congenital syphilis 3 / 4

DANBs Orthodontic Assisting (OA) Exam

Answer: B

Explanation: Habits like thumb sucking exert functional pressure that

can alter normal growth patterns, leading to malocclusion.

Question 6. During orthodontic growth, which craniofacial structure continues to develop into late adolescence?

• Maxilla
• Mandible
• Nasal bones
• Zygomatic arch

Answer: B

Explanation: The mandible continues to grow into late adolescence due

to its endochondral growth, affecting occlusion and facial profile.

Question 7. Which biomechanical principle is utilized when applying light, continuous forces to move teeth orthodontically?

• / 4