Dental Anatomy & Oral Development Flashcards

In Angle's classification, Class I occlusion is characterized by which molar relationship?

Answer: The mesiobuccal cusp of the maxillary first molar occludes in the buccal groove of the mandibular first molar

Angle's Class I (neutrocclusion) is defined by the mesiobuccal cusp of the upper first molar occluding in the buccal groove of the lower first molar, indicating a normal anteroposterior skeletal relationship.

Angle's Class II malocclusion is also referred to by which descriptive term?

Answer: Disto-occlusion

Class II is called disto-occlusion because the lower first molar is positioned distal (posterior) to its ideal Class I position, resulting in the mandible appearing retruded.

What orthodontic term describes the vertical overlap of the upper anterior teeth over the lower anterior teeth?

Answer: Overbite

Overbite measures the vertical overlap of the maxillary anterior teeth over the mandibular anterior teeth; a normal overbite is approximately 2–3 mm.

The horizontal distance between the labial surface of the upper incisors and the labial surface of the lower incisors, measured parallel to the occlusal plane, is called:

Answer: Overjet

Overjet (also called horizontal overlap) measures the horizontal protrusion of the maxillary incisors beyond the mandibular incisors; a normal overjet is approximately 2–3 mm.

Which anatomical plane divides the face and body into equal left and right halves and is used as a reference in orthodontic diagnosis?

Answer: Midsagittal plane

The midsagittal (median) plane divides the body into equal left and right halves and serves as a critical reference for assessing facial symmetry and dental midline discrepancies in orthodontics.

What is the term for a tooth that has erupted in an abnormal position outside the normal line of the dental arch?

Answer: Ectopic tooth

An ectopic tooth has erupted in an abnormal position; common examples include maxillary canines erupting palatally or a tooth erupting on the wrong side of the arch.

Which permanent tooth is known as the 'cornerstone of the dental arch' due to its long root and key position at the arch curvature?

Answer: Maxillary canine

The maxillary canine is called the cornerstone of the dental arch because it occupies the arch curvature, has the longest root of any tooth, and plays a critical role in guiding occlusion.