DDS Practice 5 — Questions and Answers
Question 1: A patient presents with a buccal space abscess originating from a maxillary first molar. Which structure must the infection perforate to reach the buccal space?
- Mylohyoid muscle
- Buccinator muscle (Correct answer)
- Masseter muscle
- Medial pterygoid muscle
Correct answer: Buccinator muscle
The buccal space lies superficial to the buccinator muscle, so infection from the maxillary molar must penetrate the buccinator to reach this space.
Question 2: When is it appropriate to use a rubber dam during endodontic treatment?
- Only when the patient requests it
- Only for posterior teeth
- For all routine root canal procedures to prevent contamination (Correct answer)
- Only when using rotary files
Correct answer: For all routine root canal procedures to prevent contamination
Rubber dam isolation is mandatory for all root canal procedures to prevent microbial contamination of the canal system and protect the patient from aspiration.
Question 3: A patient has a Kennedy Class II removable partial denture. Which design feature must be incorporated to prevent rotation of the prosthesis during function?
- Indirect retainers (Correct answer)
- Reciprocal clasp
- Major connector
- Tooth-colored clasps
Correct answer: Indirect retainers
Indirect retainers placed anterior to the fulcrum line prevent the distal extension base from tipping or rotating away from the tissue when occlusal force is applied.
Question 4: A patient with poorly controlled type 2 diabetes presents for a full-mouth debridement. Which laboratory value is most useful for assessing long-term glycemic control?
- Fasting blood glucose
- HbA1c (glycated hemoglobin) (Correct answer)
- Random blood glucose
- Serum insulin level
Correct answer: HbA1c (glycated hemoglobin)
HbA1c reflects average blood glucose over the preceding 2–3 months and is the best indicator of long-term glycemic control.
Question 5: Which tooth movement type results in the highest rate of root resorption during orthodontic treatment?
- Tipping
- Torque (root torque)
- Bodily movement
- Intrusion (Correct answer)
Correct answer: Intrusion
Intrusion is associated with the highest risk of root resorption because it concentrates pressure at the root apex.
Question 6: A patient presents with a white, non-removable plaque-like lesion on the floor of the mouth. Biopsy shows severe epithelial dysplasia. What is the recommended management?
- Antifungal therapy and observation
- Observation every 6 months
- Surgical excision with clear margins (Correct answer)
- Laser ablation without biopsy
Correct answer: Surgical excision with clear margins
Severe epithelial dysplasia carries a high risk of malignant transformation and requires surgical excision with clear margins.
Question 7: During a routine exam, a 55-year-old patient is noted to have a 1.5 cm asymptomatic bluish-purple swelling on the lower lip that blanches completely with pressure. This is most likely:
- Mucocele
- Hemangioma
- Varix (Correct answer)
- Amalgam tattoo
Correct answer: Varix
A varix (phlebectasia) is a dilated vein that blanches completely with pressure and appears as a bluish swelling, commonly found on the lower lip in older patients.
DDS Practice 5
A patient presents with a buccal space abscess originating from a maxillary first molar.
Which structure must the infection perforate to reach the buccal space?