EFDA - Expanded Function Dental Auxiliary Dental Anatomy and Occlusion Questions and Answers — Questions and Answers
Question 1: A patient presents with a Class II, Division 2 malocclusion. Which of the following characteristics is a defining feature of this classification?
- Protruded maxillary central incisors.
- A posterior crossbite.
- An open bite tendency.
- Retroclined maxillary central incisors. (Correct answer)
Correct answer: Retroclined maxillary central incisors.
Angle's Class II, Division 2 malocclusion is characterized by a Class II molar relationship where the maxillary central incisors are retroclined, or tipped back towards the palate. The lateral incisors can be either normally inclined or proclined. [1, 3, 5, 7]
Question 2: Which permanent teeth succeed the primary molars?
- Permanent molars
- Permanent premolars (Correct answer)
- Permanent canines
- Permanent incisors
Correct answer: Permanent premolars
The 20 primary teeth are replaced by permanent successors. Specifically, the primary first and second molars are exfoliated and replaced by the permanent first and second premolars (bicuspids). The permanent molars erupt distal (behind) to the primary dentition and are not succedaneous. [15, 23, 24, 25, 27]
Question 3: The Cusp of Carabelli is an accessory cusp most frequently found on which surface of which tooth?
- Mesiolingual of a maxillary first molar (Correct answer)
- Distobuccal of a mandibular first molar
- Mesiolingual of a mandibular first molar
- Distobuccal of a maxillary second molar
Correct answer: Mesiolingual of a maxillary first molar
The Cusp of Carabelli, also known as Carabelli's tubercle, is a non-functional fifth cusp located on the mesiolingual (palatal) surface of the maxillary first molar. It can also be found on primary maxillary second molars. [2, 4, 6, 8, 13, 33]
Question 4: During a protrusive movement of the mandible, which teeth ideally provide the primary guidance to disocclude the posterior teeth?
- Maxillary and mandibular canines
- Maxillary and mandibular molars
- Maxillary and mandibular incisors (Correct answer)
- Maxillary and mandibular premolars
Correct answer: Maxillary and mandibular incisors
In an ideal occlusion, protrusive movement (moving the jaw forward) results in contact between the incisal edges of the mandibular incisors and the lingual surfaces of the maxillary incisors. This contact and guidance should cause the posterior teeth to separate (disocclude). [12, 18, 20]
Question 5: Which of the following best defines centric occlusion?
- The most retruded position of the condyles in the glenoid fossa.
- The maximum intercuspation of the maxillary and mandibular teeth. (Correct answer)
- A jaw position determined solely by ligament and muscle guidance.
- The end-to-end contact of the anterior teeth.
Correct answer: The maximum intercuspation of the maxillary and mandibular teeth.
Centric occlusion, also known as maximum intercuspation (MIP), is defined by the way the teeth fit together with the most contact, regardless of the condylar position. It is a tooth-determined position. [10, 14, 16, 19]
Question 6: In a normal occlusal relationship (Class I), which cusps are considered the non-functional or non-supporting cusps?
- Buccal cusps of maxillary posterior teeth and lingual cusps of mandibular posterior teeth. (Correct answer)
- Lingual cusps of maxillary posterior teeth and buccal cusps of mandibular posterior teeth.
- Buccal cusps of both maxillary and mandibular posterior teeth.
- Lingual cusps of both maxillary and mandibular posterior teeth.
Correct answer: Buccal cusps of maxillary posterior teeth and lingual cusps of mandibular posterior teeth.
In a normal Class I occlusion, the functional (or supporting) cusps are the lingual cusps of the maxillary teeth and the buccal cusps of the mandibular teeth, as these occlude in the central fossae of the opposing teeth. Therefore, the non-functional (or shearing) cusps are the buccal cusps of the maxillary posterior teeth and the lingual cusps of the mandibular posterior teeth. [36]
EFDA - Expanded Function Dental Auxiliary Dental Anatomy and Occlusion Questions and Answers
A patient presents with a Class II, Division 2 malocclusion.
Which of the following characteristics is a defining feature of this classification?