ORE Part 1 Dental Anatomy & Occlusion 3

Question 1

Which ligament is the primary support structure of a tooth in its socket?

Accepted Answer

Periodontal ligament (PDL)

Answer

The periodontal ligament (PDL) is the fibrous connective tissue between the tooth root cementum and the alveolar bone proper. It provides support, proprioception, and nutrient supply to the alveolus.

Question 2

What is the 'contact area' of a tooth?

Accepted Answer

The area where adjacent teeth contact each other proximally in the arch

Answer

The proximal contact area is where adjacent teeth in the same arch touch. It prevents food impaction, maintains arch integrity, and protects the interdental papilla.

Question 3

What root configuration does the mandibular first molar typically have?

Accepted Answer

Two roots (mesial and distal), mesial root has two canals

Answer

The mandibular first molar typically has two roots: a mesial root (usually with two canals — mesiobuccal and mesiolingual) and a distal root (usually one or two canals).

Question 4

What is the 'tubercle of Zuckerkandl' (Carabelli cusp) and where is it found?

Accepted Answer

An accessory cusp on the mesiopalatal cusp of the maxillary first molar

Answer

The Cusp of Carabelli is a 5th (accessory) cusp found on the mesiopalatal surface of the maxillary first molar (occasionally second molar). It is more common in people of European descent.

Question 5

What is the 'terminal plane' in primary dentition and its significance for permanent molar eruption?

Accepted Answer

The relationship between primary second molars distally — mesial step (ideal for Class I), flush terminal plane (may give Class I or II), or distal step (leads to Class II)

Answer

The terminal plane describes how the distal surfaces of the upper and lower primary second molars relate. A mesial step favours a Class I permanent molar relationship; a flush terminal plane may lead to Class I or Class II; a distal step typically leads to Class II.

ORE Part 1 Practice Test

ORE Part 1 Practice Test

ORE Part 1 Dental Anatomy & Occlusion 3