NBDE Dental Anatomy and Occlusion 4 — Questions and Answers
Question 1: In Angle's Class II, Division 2 malocclusion, the maxillary central incisors are characteristically:
- Proclined with a large overjet
- Retroclined with a deep overbite (Correct answer)
- Crossbite with the mandibular incisors
- Spaced and upright
Correct answer: Retroclined with a deep overbite
Class II, Division 2 is characterized by retroclination (lingual tipping) of the maxillary central incisors and an increased deep overbite.
Question 2: The oblique ridge on the maxillary first molar connects which two cusps?
- Mesiobuccal and mesiolingual cusps
- Distobuccal and mesiolingual cusps (Correct answer)
- Mesiobuccal and distolingual cusps
- Distobuccal and distolingual cusps
Correct answer: Distobuccal and mesiolingual cusps
The oblique ridge on the maxillary first molar is a transverse ridge connecting the distobuccal and mesiolingual cusps diagonally across the occlusal surface.
Question 3: The Bennett movement refers to:
- The protrusive path of the mandibular condyle
- The lateral bodily shift of the mandible toward the working side (Correct answer)
- The rotation of the condyle on the balancing side
- The retrusive arc of the mandible from centric occlusion
Correct answer: The lateral bodily shift of the mandible toward the working side
Bennett movement is the lateral bodily shift of the entire mandible toward the working side during lateral excursion.
Question 4: Which tooth is most commonly congenitally missing (excluding third molars)?
- Maxillary lateral incisor
- Mandibular second premolar (Correct answer)
- Maxillary second premolar
- Mandibular lateral incisor
Correct answer: Mandibular second premolar
Excluding third molars, the mandibular second premolar has the highest prevalence of congenital absence (hypodontia).
Question 5: The term 'intercuspation' refers to:
- The relationship between condyle and articular disc
- The fitting together of upper and lower cusp tips in occlusion (Correct answer)
- The lateral movement of cusps during chewing
- The vertical overlap of anterior teeth
Correct answer: The fitting together of upper and lower cusp tips in occlusion
Intercuspation describes the occlusal relationship where opposing cusp tips, ridges, and fossae fit together when the teeth are in contact.
Question 6: Which permanent tooth has the largest pulp chamber relative to its crown size?
- Maxillary first molar (Correct answer)
- Mandibular second molar
- Maxillary canine
- Mandibular central incisor
Correct answer: Maxillary first molar
The maxillary first molar has the largest pulp chamber of all permanent teeth, which is relevant for endodontic access preparation.
Question 7: During mastication, the power stroke of the mandible occurs:
- During the opening phase of the chewing cycle
- During the closing phase as teeth come into contact (Correct answer)
- During the lateral excursion away from food
- During the rest position between chewing cycles
Correct answer: During the closing phase as teeth come into contact
The power stroke occurs during the closing phase of mastication when teeth contact food and generate occlusal forces for food breakdown.
NBDE Dental Anatomy and Occlusion 4
In Angle's Class II, Division 2 malocclusion, the maxillary central incisors are characteristically: