Pop Quiz Part 1

Q1: What are the anatomical features used to determine Angle's classes of occlusion?

A1: The key anatomical features used to determine Angle's classes of occlusion are:

• The position of the mesiobuccal cusp of the maxillary first molar in relation to the buccal groove of the mandibular first molar.

• The position of the mandible.

• The angle of the central incisors on both jaws.

Q2: How is Angle's Class I occlusion defined?

A2: In Angle's Class I occlusion, the mesio-buccal cusp of the maxillary first molar occludes with the buccal groove of the mandibular first molar. The central incisors of the mandible also directly sit underneath the cingulum of the maxillary central incisors.

Q3: How is Angle's Class II occlusion defined?

A3: In Angle's Class II occlusion, the mesio-buccal cusp of the maxillary first molar occludes mesial to the buccal groove of the mandibular first molar. The central incisors of the mandible are not directly under the cingulum of the maxillary central incisors, but are instead behind them, leading to an overjet.

Q4: How is Angle's Class III occlusion defined?

A4: In Angle's Class III occlusion, the mesio-buccal cusp of the maxillary first molar occludes distal to the buccal groove of the mandibular first molar. The central incisors of the mandible also overlap the central incisors of the maxilla.

Q5: What is centric occlusion?

A5: Centric occlusion occurs when the teeth of the maxilla and mandible are closed in maximum intercuspation, with the posterior teeth in the most functional relationship.

Q6: What is the term "retrognathic" referring to?

A6: The term "retrognathic" refers to the abnormally retruded position of the mandible, characteristic of Angle's Class II occlusion.

Q7: What is the term "prognathic" referring to?

A7: The term "prognathic" refers to the abnormally forward position of the mandible, characteristic of Angle's Class III occlusion.

Q8: What is lateral excursion?

A8: Lateral excursion refers to the side-to-side movement of the mandible during mastication.

Q9: What is the main cause of anterior crowding?

A9: The main cause of anterior crowding is the eruption of the third molars, which causes mesial pressure and displaces the anterior teeth.

Q10: Which teeth are most likely affected by anterior crowding, and why?

A10: The incisors are most likely to be rotated out of position due to anterior crowding, as they have shallow, single roots that make them more susceptible to displacement.