NDEB Dental Anatomy and Occlusion 2 — Questions and Answers
Question 1: In Angle Class I occlusion, the mesiobuccal cusp of the maxillary first molar occludes in the:
- Mesial pit of the mandibular first molar
- Buccal groove of the mandibular first molar (Correct answer)
- Distal fossa of the mandibular first molar
- Mesial fossa of the mandibular second molar
Correct answer: Buccal groove of the mandibular first molar
Angle Class I is defined by the mesiobuccal cusp of the maxillary first molar occluding in the buccal groove of the mandibular first molar.
Question 2: Centric relation is best described as:
- Maximum intercuspation of all teeth
- The position where the condyles are in their most superior-anterior position against the articular eminences (Correct answer)
- The rest position of the mandible with 2–4 mm freeway space
- The habitual closing position of the mandible
Correct answer: The position where the condyles are in their most superior-anterior position against the articular eminences
Centric relation is a reproducible, load-bearing jaw position where the condyles and discs are seated in the most superior-anterior position against the articular eminences.
Question 3: Bennett movement is defined as:
- Rotational hinge movement of the condyle during mouth opening
- The bodily lateral shift of the mandible toward the working side during lateral excursion (Correct answer)
- Protrusive movement of the mandible in the sagittal plane
- Retrusion of the mandible from intercuspal position to centric relation
Correct answer: The bodily lateral shift of the mandible toward the working side during lateral excursion
Bennett movement is the bodily lateral translation of the entire mandible toward the working side that occurs during lateral excursion.
Question 4: During lateral excursion of the mandible, the non-working (balancing) side condyle moves:
- Upward and posteriorly
- Downward, forward, and medially (Correct answer)
- Only laterally without vertical change
- Remains stationary within the glenoid fossa
Correct answer: Downward, forward, and medially
The non-working side condyle orbits downward, forward, and medially along the articular eminence during lateral mandibular excursion.
Question 5: Canine-protected occlusion (canine guidance) is characterized by:
- All posterior teeth sharing load equally during lateral excursions
- The canine tooth directing all mandibular movements including protrusion
- The canine discluding all posterior teeth during lateral excursions (Correct answer)
- Bilateral balanced contact on both working and non-working sides
Correct answer: The canine discluding all posterior teeth during lateral excursions
In canine guidance, the contacting canines during lateral excursion create disclusion (separation) of all posterior teeth, reducing harmful lateral forces on the posterior dentition.
Question 6: The Curve of Spee is best described as:
- A lateral curve through the buccal and lingual cusp tips of mandibular posterior teeth
- The anteroposterior curvature through the buccal cusp tips of mandibular teeth from canine to third molar (Correct answer)
- The curvature connecting mesial and distal marginal ridges of posterior teeth
- The lateral curvature of the maxillary arch in the frontal plane
Correct answer: The anteroposterior curvature through the buccal cusp tips of mandibular teeth from canine to third molar
The Curve of Spee is the anteroposterior curvature formed by connecting the cusp tips of mandibular posterior teeth from the canine through the third molar.
Question 7: Angle Class II, Division 2 malocclusion is characterized by:
- Mesial molar relationship with proclined maxillary incisors
- Distal molar relationship with retroclined maxillary central incisors (Correct answer)
- Normal molar relationship with a deep overbite only
- Distal molar relationship with severely proclined maxillary central incisors
Correct answer: Distal molar relationship with retroclined maxillary central incisors
Class II Division 2 features a distal (Class II) molar relationship combined with lingually inclined (retroclined) maxillary central incisors, often with a deep overbite.
NDEB Dental Anatomy and Occlusion 2
In Angle Class I occlusion, the mesiobuccal cusp of the maxillary first molar occludes in the: