DHA Pediatric Dentistry exam questions

6 worked Pediatric Dentistry practice questions

Original exam-style questions from the bank, spread across the blueprint domains. They are not real or recalled exam questions. Try each one, then open the answer for the rationale and reference. None of them appear in the free mock exam, so reading them will not spoil it.

1. Question 1 · Behaviour Guidance, Sedation and Anesthesia

   A healthy 20 kg child needs local anesthesia with 2% lidocaine and 1:100,000 epinephrine in 1.8 mL cartridges. Using a maximum of 4.4 mg/kg, what is the maximum dose?

   1. A140 mg, about 3.9 cartridges
   2. B44 mg, about 1.2 cartridges
   3. C176 mg, about 4.9 cartridges
   4. D88 mg, about 2.4 cartridges
   Show answer and explanation

   Correct answer: D. 88 mg, about 2.4 cartridges

   4.4 mg/kg x 20 kg = 88 mg; each 1.8 mL cartridge of 2% lidocaine contains 36 mg, so 88/36 is about 2.4 cartridges. Using the adult 7 mg/kg figure gives 140 mg and risks toxicity in a child.

   Reference: AAPD Use of Local Anesthesia for Pediatric Dental Patients

2. Question 2 · Caries Risk and Prevention

   In early childhood caries associated with prolonged bottle feeding, which teeth are typically spared?

   1. AMandibular incisors
   2. BMaxillary incisors
   3. CMaxillary first primary molars
   4. DMandibular first primary molars
   Show answer and explanation

   Correct answer: A. Mandibular incisors

   The mandibular incisors are protected by the tongue and the nearby sublingual and submandibular salivary flow. The maxillary incisors are usually affected first.

   Reference: McDonald and Avery's Dentistry for the Child and Adolescent, 11th ed.

3. Question 3 · Child Protection, Ethics and Infection Control

   Who normally gives informed consent for elective dental treatment for a 6-year-old?

   1. AThe child alone
   2. BThe parent or legal guardian
   3. CThe school teacher
   4. DAny accompanying adult relative
   Show answer and explanation

   Correct answer: B. The parent or legal guardian

   Consent for a young child is given by the parent or legal guardian, while the child's assent should still be sought. An accompanying relative without legal authority cannot consent.

   Reference: AAPD Informed Consent

4. Question 4 · Growth, Development and Eruption

   In the mixed dentition analysis, how does leeway space typically compare between the arches?

   1. ALarger in the maxilla, about 2.5 mm per side
   2. BEqual in both arches, about 1 mm per side
   3. CLarger in the maxilla, about 4 mm per side
   4. DLarger in the mandible, about 2.5 mm per side
   Show answer and explanation

   Correct answer: D. Larger in the mandible, about 2.5 mm per side

   Leeway space averages about 2.5 mm per side in the mandible and 1.5 mm per side in the maxilla, mainly from the larger primary second molars. The greater mandibular space allows mesial shift of the lower first molars into Class I.

   Reference: Proffit, Contemporary Orthodontics, 6th ed.

5. Question 5 · Growth, Development and Eruption

   A 2-year-old has lost several primary incisors spontaneously without trauma; the exfoliated teeth have complete roots. Serum alkaline phosphatase is low. What is the most likely diagnosis?

   1. AHypophosphatasia
   2. BLangerhans cell histiocytosis
   3. CPapillon-Lefevre syndrome
   4. DDentinogenesis imperfecta
   Show answer and explanation

   Correct answer: A. Hypophosphatasia

   Hypophosphatasia causes defective cementum, so primary teeth exfoliate early with intact roots, and serum alkaline phosphatase is low. Papillon-Lefevre syndrome causes severe periodontitis with palmoplantar keratosis and normal alkaline phosphatase.

   Reference: Cameron and Widmer, Handbook of Pediatric Dentistry, 5th ed.

6. Question 6 · Interceptive Orthodontics and Space Management

   A 5-year-old needs extraction of a primary second molar before eruption of the first permanent molar. Which space maintainer is indicated?

   1. ADistal shoe appliance
   2. BBand and loop
   3. CLower lingual holding arch
   4. DNance palatal arch
   Show answer and explanation

   Correct answer: A. Distal shoe appliance

   A distal shoe guides the unerupted first permanent molar into position when the primary second molar is lost early. Band and loop, lingual arch and Nance appliances all need erupted abutment teeth.

   Reference: AAPD Management of the Developing Dentition and Occlusion