ORE Part 1 Dental Anatomy & Occlusion

Question 1

How many cusps does a maxillary first molar typically have?

Accepted Answer

4 cusps (with a 5th Cusp of Carabelli occasionally)

Answer

The maxillary first molar has 4 main cusps: mesiobuccal, distobuccal, mesiopalatal (largest), and distopalatal. The Cusp of Carabelli is an accessory cusp on the mesiopalatal cusp, present in about 60% of individuals.

Question 2

What is the angle formed between the occlusal plane and the condylar guidance path called?

Accepted Answer

The Fischer angle (or Bennett angle — actually these differ; the angle between condylar path and occlusal plane is the Balkwill angle)

Answer

The Balkwill angle (approximately 26°) is formed between the occlusal plane and the path of the condyle. The Bennett angle is the angle formed by the working side condyle moving laterally.

Question 3

What is Angle's Class II Division 2 malocclusion characterised by?

Accepted Answer

Retrognathic mandible, upper central incisors retroclined, deep overbite, and increased overjet that may be masked by retroclination

Answer

Angle Class II Div 2 features a distal molar relationship, retroclined upper central incisors (distinguishing it from Div 1), upper lateral incisors often proclined, and typically a deep overbite with reduced overjet.

Question 4

Which permanent tooth has the longest root?

Accepted Answer

Maxillary canine

Answer

The maxillary canine has the longest root of all permanent teeth, making it very stable in the arch and explaining why it is typically the last anterior tooth extracted when arch preservation is needed.

Question 5

In the primary dentition, which tooth does NOT have a permanent successor?

Accepted Answer

Primary second molar (replaced by a permanent premolar)

Answer

All primary teeth are replaced by permanent successors: primary incisors and canines by permanent incisors and canines; primary molars are replaced by premolars (not permanent molars).

ORE Part 1 Practice Test

ORE Part 1 Practice Test

ORE Part 1 Dental Anatomy & Occlusion