MJDF Dental Anatomy & Physiology 1 — Questions and Answers
Question 1: How many cusps does a mandibular first molar typically have?
- Five (three buccal, two lingual) (Correct answer)
- Four
- Six
- Three
Correct answer: Five (three buccal, two lingual)
The mandibular first molar classically has five cusps: mesiobuccal, distobuccal, distal (buccal), mesiolingual, and distolingual, making it the largest and most complex mandibular molar.
Question 2: Which tooth has the longest root in the permanent dentition?
- Maxillary canine (Correct answer)
- Mandibular first molar
- Maxillary central incisor
- Mandibular canine
Correct answer: Maxillary canine
The maxillary canine has the longest single root in the permanent dentition, which also accounts for its relatively late eruption and prominence in arch stability.
Question 3: What is the primary function of the periodontal ligament (PDL)?
- Suspend the tooth in the alveolus, transmit occlusal forces, and provide sensory feedback (Correct answer)
- Provide nutrition to the enamel
- Form secondary dentine
- Mineralise the cementum
Correct answer: Suspend the tooth in the alveolus, transmit occlusal forces, and provide sensory feedback
The PDL suspends the tooth with Sharpey's fibres, transmits and absorbs occlusal forces, provides proprioception, and supports tooth eruption and remodelling.
Question 4: Which structure forms the bulk of the tooth and determines its overall shape?
- Dentine (Correct answer)
- Enamel
- Cementum
- Pulp
Correct answer: Dentine
Dentine constitutes the bulk of the tooth crown and root, forming its underlying shape; enamel covers the coronal dentine while cementum covers the root dentine.
Question 5: What type of epithelium lines the oral mucosa of the hard palate?
- Keratinised stratified squamous epithelium (Correct answer)
- Non-keratinised stratified squamous
- Simple columnar
- Pseudostratified columnar
Correct answer: Keratinised stratified squamous epithelium
The hard palate is covered by keratinised stratified squamous epithelium, providing durability against masticatory forces and friction from food.
Question 6: What is the average length of the maxillary central incisor root?
- 13 mm (Correct answer)
- 8 mm
- 10 mm
- 17 mm
Correct answer: 13 mm
The maxillary central incisor root averages approximately 13 mm in length; knowledge of root lengths is important for endodontic working length determination.
MJDF Dental Anatomy & Physiology 1
How many cusps does a mandibular first molar typically have?