EFDA Anatomy and Occlusion 5 — Questions and Answers
Question 1: The root trunk of a multi-rooted tooth refers to the area:
- At the apex of each root
- Between the CEJ and the furcation (Correct answer)
- Inside the pulp chamber floor
- Covered by alveolar bone only
Correct answer: Between the CEJ and the furcation
The root trunk is the undivided portion of the root between the cementoenamel junction and the furcation where the roots diverge.
Question 2: Which of the following teeth is MOST likely to have three roots?
- Maxillary first premolar
- Mandibular first molar
- Maxillary first molar (Correct answer)
- Mandibular second premolar
Correct answer: Maxillary first molar
The maxillary first molar classically has three roots: mesiobuccal, distobuccal, and palatal (lingual).
Question 3: Curve of Spee refers to the:
- Lateral curve of the dental arch when viewed from above
- Anteroposterior curvature of the occlusal plane from canine to last molar (Correct answer)
- Curve of the mandibular arch in centric relation
- Vertical overlap of anterior teeth
Correct answer: Anteroposterior curvature of the occlusal plane from canine to last molar
The curve of Spee is the anteroposterior (sagittal) curvature of the mandibular occlusal plane, curving upward from the canine back through the molars.
Question 4: A patient has an overbite of 6 mm. This is best described as:
- Increased vertical overlap of anterior teeth (Correct answer)
- Increased horizontal projection of upper incisors
- Posterior crossbite
- End-to-end incisal relationship
Correct answer: Increased vertical overlap of anterior teeth
Overbite is the vertical overlap of the maxillary incisors over the mandibular incisors; 6 mm exceeds the normal range of 1–3 mm and is considered a deep bite.
Question 5: The lateral pterygoid muscle is PRIMARILY responsible for which mandibular movement?
- Elevation and retrusion
- Depression and protrusion
- Lateral movement and protrusion (Correct answer)
- Elevation and lateral movement
Correct answer: Lateral movement and protrusion
The lateral pterygoid protrudes the mandible and, acting unilaterally, produces lateral (sideways) movement; it also assists in depression.
Question 6: In dentistry, the term 'embrasure' refers to:
- The contact area between two adjacent teeth
- The V-shaped space occlusal or facial to the contact area between adjacent teeth (Correct answer)
- The groove between a cusp and the marginal ridge
- The concave area on the root surface
Correct answer: The V-shaped space occlusal or facial to the contact area between adjacent teeth
An embrasure is the triangular space that flares outward from the interproximal contact area, classified as buccal, lingual, occlusal, or gingival embrasures.
Question 7: Which deciduous (primary) tooth is the LARGEST in the primary dentition?
- Maxillary primary canine
- Mandibular primary first molar
- Maxillary primary second molar (Correct answer)
- Mandibular primary second molar
Correct answer: Maxillary primary second molar
The maxillary primary second molar is the largest primary tooth and resembles the permanent maxillary first molar in morphology.
EFDA Anatomy and Occlusion 5
The root trunk of a multi-rooted tooth refers to the area: