Child Dental Health and Orthodontics

Question 1

1. What are the correct dates of root completion for a) U2 b) U6 c) L3, L7?
   a. 8, 10-12, 12-14, 17
   b. 13, 10-12, 14-15, 12-14
   c. 11, 14-15, 12-14, 14-15
   d. 11, 9-10, 12-14, 14-15
   e. 9, 10-12, 13-15, 18-21

Answer 1

 D. 11, 9-10, 12-14, 14-15
 The root completion dates can be worked out from the order of eruption in these four teeth. The order of eruption is maxillary first permanent molar, followed by maxillary lateral incisor, then the mandibular canine, then finally the mandibular second permanent molar.

Question 2

2. What is the definition of subluxation?
   a. The loss of a tooth from the socket which is then replaced within that socket.
   b. The loosening of the tooth within the socket without any displacement.
   c. Injury to the supporting tissues of a tooth without displacement.
   d. Injury to the supporting tissues of a tooth with displacement.
   e. Trauma causes fracture of the alveolar bone leading to displacement.

Answer 2

 B. The loosening of the tooth within the socket without any displacement.
 A = reimplantation C = concussion and the others are not specific definitions.

Question 3

3. What is the recommended dosage of fluoride tablets and drops (mg F/day), related to the concentration of fluoride in the drinking water?

Answer 3

 Answer A – learn in BNF.

Question 4

4. A Class II division 2 malocclusion as defined by Angle is:
   a. The lower arch should be at least one-half cusp width posterior to the upper and the upper central incisors should be proclined.
   b. The upper arch should be at least one-half cusp width posterior to the upper and the upper central incisors should be retroclined.
   c. The upper arch should be at least one-half cusp width posterior to the upper and the upper central incisors should be proclined.
   d. The lower arch should be at least one-half cusp width too far forward to the upper and the upper central incisors should be retroclined.
   e. The lower arch should be at least one-half cusp width posterior to the upper and the upper central incisors should be retroclined.

Answer 4

 E. The lower arch should be at least one-half cusp width posterior to the upper and the upper central incisors should be retroclined.
 The starting point of the thought process of elimination should be that Class II div 2 consists of Retroclined incisors. The lower arch is post-normal and therefore E is only option.

Question 5

5. Which one of the following may be a sign that a child has been wearing their orthodontic appliance?
   a. The acrylic still has a glossy sheen
   b. Poor speech
   c. The springs are loose at the review appointment
   d. The child is having difficulty inserting their appliance
   e. There is no change in the occlusion

Answer 5

 C. The springs are loose at the review appointment
 This is the only sign of use, as the springs would be loose because of the movement of the teeth. The acrylic would be duller by the saliva in the mouth, the child’s speech would have adapted the appliance, and he or she would be competent at inserting the appliance.

Question 6

6. A panicking mother informs you that her 3-year-old child’s upper central deciduous incisor has avulsed. What advice would you give her?
   a. Store the tooth in milk and bring the child to the surgery immediately.
   b. Store the tooth in cold water and bring the child to the surgery.
   c. Tell the mother to try to reinsert the tooth into the socket, apply pressure and attend the surgery.
   d. Attend the surgery immediately with the tooth, but no special precautions for storage of the tooth.
   e. Store the tooth in chlorhexidine mouthwash and attend the surgery immediately.

Answer 6

 D. Attend the surgery immediately with the tooth, but no special precautions for storage of the tooth.
 The clue is in the age of the patient! The child is three years old and has only deciduous teeth, which should not be reimplanted. It is prudent to see the child immediately at the practice to check that the entire tooth has avulsed, and to check for any other injuries to the child.

Question 7

7. What is the material of choice for a devitalising pulpotomy?
   a. Calcium hydroxide
   b. Formocresol
   c. Ferric sulphate
   d. Beechwood creosote
   e. Tranexamic acid

Answer 7

 C. Ferric sulphate
 Formocresol or Beechwood Creosoate used to be indicated for a non-vital pulpotomy, however there have been concerns about the oncogenic nature of the above treatments. Ferric sulphate is now the treatment of choice. Tranexamic acid is used after extraction in cases where haemostasis has not been achieved.

Question 8

8. A 9-year-old child requires extraction of her upper right first permanent molar under local anaesthesia. Her medical history is unremarkable except that she had rheumatic fever at 3 years of age and a chest infection 4 months ago, which was treated with penicillin. What is the correct precaution for this child?
   a. No antibiotics required for prophylaxis
   b. 600mg clindamycin orally 1 hour pre-operatively
   c. 750mg amoxicillin orally 1 hour pre-operatively
   d. 3g amoxicillin orally 1 hour pre-operatively
   e. 3g amoxicillin intravenously 1 hour pre-operatively

Answer 8

 A. No antibiotics required for prophylaxis
 Pre-operative antibiotic prophylaxis is not recommended in this case. Check NICE guidelines.

Question 9

9. A 13-year-old child present with a retained upper left deciduous canine. The successor is not palpable. What would be the most appropriate investigation.
   a. Orthopantomogram (OPG) and periapical radiograph
   b. Periapical radiograph
   c. Vitality test of the deciduous canine
   d. OPG
   e. Lateral cephalogram

Answer 9

 A. Orthopantomogram and periapical radiograph
 Known as parallax technique, and enables you to assess whether the missing tooth is placed palatally or buccally. If the tooth is palatally placed it will appear to have moved in the same direction as the x-ray tubehead. If the converse is true then it is placed buccally. SLOB (same lingual, opposite buccal).

Question 10

10. Which one of the following defines the Frankfort plane?
    a. Distance between the upper and lower incisors in the vertical plane.
    b. Line joining porion (superior aspect of external auditory meatus) with orbitale (lowermost point of bony orbit)
    c. Distance between the upper and lower incisors in horizontal plane.
    d. Line joining nasion (most anterior point on fronto-nasal suture) with orbitale (lowermost point of bony orbit)
    e. Line joining porion (superior aspect of external auditory meatus) with nasion (most anterior point on fronto-nasal suture).

Answer 10

 B. Line joining porion (superior aspect of external auditory meatus) with orbitale (lowermost point of bony orbit)
 A defines overbite. C defines overjet. And the others are false.

Question 11

11. Which one of the following does not cause staining of teeth?
    a. Porphyria
    b. Products of pulpal necrosis
    c. Cefotaxime
    d. Chlorhexidine
    e. Tetracycline

Answer 11

 C. Cefotaxime
 Porphyria causes red staining of teeth, product of pulpal necrosis lead to a grey appearance of the enamel, chlorhexidine leads to brown staining and tetracycline leads to blue/brown banding of the teeth.

Question 12

12. A patient presents with an increased overjet of 7mm, an anterior open bite of 5mm, and a lower left second permanent molar partially erupted and impacted against the first permanent molar. Which Index of Orthodontic Treatment Need (IOTN) category would the patient fall into?
    a. 1 (none)
    b. 2 (little)
    c. 3 (moderate)
    d. 4 (great)
    e. 5 (very great)

Answer 12

 D. 4 (great)
 Having an overjet 6-9mm, an open bite of greater than 4mm and partially erupted, impacted teeth places the patient in the IOTN 4 category.

Question 13

13. Which one of the following tables shows normal measurements on a cephalometric tracing? A) SNA B) SNB C) ANB
    a. 81 +/- 3, 79+/- 3, 3+/-2
    b. 79+/-3, 3+/-3, 81+/-2
    c. 81+/-3, 3+/-3, 79+/-2
    d. 79+/-3, 81+/-3, 3+/-2
    e. 3+/-2, 79+/-3, 81+/-2

Answer 13

 A. 81+/- 3, 79+/- 3, 3+/-2
 These angulations are very important to know as they enable you to correlate your clinical findings with your radiographic findings. This enables you to confirm the classification of your patient skeletally.

Question 14

14. Which one of the following defines the mandibular plane?
    a. Porion to orbitale
    b. Posterior nasal spine to anterior nasal spine
    c. Gonion to menton
    d. Porion to menton
    e. Gonion to porion

Answer 14

 C. Gonion to menton
 Knowing the anatomical points of a cephalometric tracing are important, and the only two points which are on the mandible are gonion and menton. The gonion is defined as the most posterior inferior point on the angle of the mandible. Menton is defined as the lowermost point on the mandibular symphysis.

Question 15

15. An anxious mother presents to your surgery with her 4-month-old child who is febrile, has cervical lymphadenopathy, and a combination of vesicles and ulcers on the gingivae and oral mucosa. What is your diagnosis?
    a. Teething
    b. Dentoalveolar abscess
    c. Primary herpetic gingivostomatitis
    d. Impetigo
    e. Traumatic ulceration

Answer 15

 C. Primary herpetic gingivostomatitis
 The child has lymphadenopathy which rules out A and E. impetigo presents periorally, not intraorally. The description is of primary herpetic gingivostomatitis, and should be managed with soft diet, fluids and review.

Question 16

16. A child presents with a mid-third root fracture of his upper right permanent central incisor. You choose to splint the tooth, and the mother asks ‘for how long will the splint be on the teeth?’. You reply:
    a. 1 week
    b. 2 weeks
    c. 4 weeks
    d. 4 months
    e. 6 months

Answer 16

 C. 4 weeks.
 Stabilise the mobile coronal segment with a passive and flexible splint for 4 weeks. If the fracture is located cervically, stabilisation for a longer period of time (up to 4 months) may be needed.

Question 17

17. Which one of the following statements regarding how deciduous molars differ from permanent molars is correct?
    a. Deciduous molars have thinner enamel, a less bulbous crown and larger pulp horns than permanent molars.
    b. Deciduous molars have thinner enamel, a more bulbous crown and smaller pulp horns than permanent molars.
    c. Deciduous molars have thinner enamel, a less bulbous crown and smaller pulp horns than permanent molars.
    d. Deciduous molars have thicker enamel, a less bulbous crown and larger pulp horns than permanent molars.
    e. Deciduous molars have thinner enamel, a less bulbous crown and larger pulp horns than permanent molars.

Answer 17

 E. Deciduous molars have thinner enamel, a less bulbous crown and larger pulp horns than permanent molars.
 The greater bulbosity of the crown makes it more difficult to place a matrix band on deciduous molars. The pulp horns are larger in deciduous teeth.

Question 18

18. A failure of fusion of which of the following leads to formation of a cleft lip?
    a. Lateral palatal shelves and the primary nasal process
    b. Maxillary processes and the median nasal process
    c. Maxillary processes and the lateral palatal shelves
    d. Mandibular processes and the maxillary processes
    e. Lateral palatal shelves and the median nasal processes

Answer 18

 B. Maxillary processes and the median nasal process
 A cleft lip is formed because of the failure of fusion of the maxillary and median nasal processes. This is to be differentiated from cleft palate which is formed by the failure of the lateral palatal shelves to rotate downwards and fuse behind the primary palate

Question 19

19. Patients with a cleft lip often have which skeletal relationship?
    a. Class I
    b. Class II div 1
    c. Class II div 2
    d. Class II div 1 or class II div 2
    e. Class III

Answer 19

 E. Class III
 Due to the failure of the maxilla to grow in proportion with the rest of the face, the maxilla is often smaller than the mandible and therefore the patient has a skeletal class III relationship.

Question 20

20. A 15-year-old patient who is still a thumb sucker attends your surgery for an orthodontic assessment. Which malocclusion is she likely to have?
    a. Posterior open bite
    b. Anterior open bite
    c. Increased overbite
    d. Median diastema
    e. Class III skeletal relationship

Answer 20

 B. Anterior open bite
 Thumb sucking leads to Proclination of the upper incisors and retroclination of the lower incisors which can cause a decreased overbite or anterior open bite. The patient may have a median diastema or Class III skeletal relationship, but this would not be as a result of the thumb sucking.

Question 21

Which one of the following is not a good method of child behaviour management?
a. Behaviour shaping
b. Desensitisation
c. Tell, show, do
d. Positive reinforcement
e. Sensitisation

Answer 21

 E. Sensitisation
 The first four are well-recognised behaviour management techniques. Sensitisation is the opposite of what we are trying to achieve.

Question 22

22. The freeway space is defined as:
    a. The interocclusal clearance when the mandible is in the rest position.
    b. The projection of the jaws from beneath the cranial base
    c. The space between the occlusal surfaces of the teeth when the mandible is in a position of habitual posture.
    d. The sagittal movement of the mandible during closure from a habitual position to centric occlusion
    e. The position of the mandible when the muscles which are acting on it show minimal activity

Answer 22

 A. The interocclusal clearance when the mandible is in the rest position.
 B defines prognathism, C defined interocclusal space, D defines mandibular deviation, E defines the rest position.

Question 23

23. What teeth should a 9-year-old child have in a given quadrant?
    a. 12CDE6
    b. 1BCDE6
    c. 12CDE
    d. ABCDE6
    e. 1234E6

Answer 23

 A. 12CDE6
 Answer B would be more likely for an 8-year-old. Answer D is likely to be a 7-year-old. C and E are not correct.

Question 24

24. What is shown in the figure below?
    a. A Southend clasp
    b. A Roberts clasp
    c. An Adams clasp
    d. A self-supporting spring
    e. A labial bow

Answer 24

 C. An Adams clasp

Question 25

25. At what age should you try to locate the upper canines?
    a. 6 years
    b. 8 years
    c. 10 years
    d. 13 years
    e. 16 years

Answer 25

 C. 10 years
 Canines should be located by 10 years of age. It is important to locate them as they are frequently unerupted. This can lead to non-vitality of maxillary lateral and central incisors due to the resorption of their roots. The resorption occurs due to the force of the unerupted canine moving in an incorrect pathway of eruption.

Question 26

26. Which one of the following is not a cause of a median diastema?
    a. Normal development
    b. Microdontia
    c. Hypodontia
    d. Lingual frenum
    e. Midline supernumerary

Answer 26

 D. Lingual frenum
 The presence of a lingual frenum has no effect on the positioning of the upper central incisors.

Question 27

27. Which one of the following is not a part of a removable appliance?
    a. Active component
    b. Retention
    c. Anchorage
    d. Baseplate
    e. Bracket

Answer 27

 E. Bracket
 A bracket is part of a fixed appliance. All the others are important parts of a removable appliance.

Question 28

28. Which one of the following is a side effect of treatment with phenytoin, which is commonly prescribed for childhood epilepsy?
    a. Staining of teeth
    b. Gingival hyperplasia
    c. Mental retardation
    d. Taurodontism
    e. Hutchinson’s incisors

Answer 28

 B. Gingival hyperplasia.
 Hutchinson’s incisors are caused by congenital syphilis. Taurodontism is unrelated to any causative factors, and staining is classically related to tetracycline.

Question 29

29. What is the angulation of the Frankfort plane?
    a. 91*
    b. 97*
    c. 109*
    d. 119*
    e. 126*

Answer 29

 C. 109*
 The Frankfort plane is described as the plan through the orbitale and porion. This is meant to approximate the horizontal plane when the head is in the free postural position.

Question 30

30. When performing inhalation sedation for children, which is the gas used?
    a. 40% nitrous oxide
    b. 100% nitrous oxide
    c. Midazolam
    d. Halothane
    e. Ether

Answer 30

 A. 40% nitrous oxide.
 100% nitrous oxide will result in death of the child, midazolam is an intravenous sedation agent, and halothane and Fluothane are general anaesthetic agents.

Question 31

31. In orthodontic treatment planning, which one of the following is incorrect?
    a. Relieve crowding
    b. Correct crossbite
    c. Align arches
    d. Maintain overbite
    e. Maintain overjet

Answer 31

 E. Maintain overjet
 When planning orthodontic treatment, one of the aims is to usually reduce or improve the overjet.

Question 32

32. The overlap of the incisors in the vertical plane is defined as:
    a. Overbite
    b. Overjet
    c. Crossbite
    d. Leeway space
    e. Frankfort plane

Answer 32

 A. Overbite

Question 33

33. An injury to the supporting tissue of the tooth without displacement of the tooth defines which type of injury?
    a. Concussion
    b. Luxation
    c. Subluxation
    d. Intrusion
    e. Extrusion

Answer 33

 A. Concussion
 Luxation is defined as displacement of the tooth. Subluxation is defined as the loosening of a tooth without displacement. Intrusion is defined as displacement of a tooth into its socket. Extrusion is defined as the partial displacement of a tooth from its socket.

Question 34

34. Which condition is associated with mulberry molars in children?
    a. Autism
    b. Down’s syndrome
    c. Osgood syndrome
    d. Syphilis
    e. Diabetes mellitus

Answer 34

 D. Syphilis
 A mulberry molar is a tooth with alternating non-anatomical depressions and rounded enamel nodules on its crown surface. It is usually associated with congenital syphilis.

Question 35

35. When describing cleft lip and palate using Veau’s classification a Veau II involves:
    a. The soft palate
    b. The soft and hard palate
    c. The soft palate, hard palate and the alveolus on one side
    d. The soft palate, hard palate and the alveolus on both sides
    e. The Veau classification does not exist

Answer 35

 B. The soft and hard palate
 There is no universally accepted classification of clefts, although the most commonly used is the Veau classification, which was described in 1931.
o Veau Class I is an isolated soft palate cleft
o Veau Class II is a hard/soft cleft palate
o Veau Class III is unilateral cleft lip and palate
o Veau Class IV is bilateral cleft of the lip and palate
 Most surgeons describe the defect rather than using the Veau system. For example Veau Class III would be described as a unilateral complete cleft of the lip, alveolus, primary and secondary palates.

Question 36

36. Which one of the following statements about non-accidental injury is true?
    a. Usually older children are involved.
    b. Frenal tears are common when a child falls.
    c. The child and parent’s version of events is similar.
    d. It is unusual to find bruises of different vintages on children.
    e. There is often a delay in seeking treatment with these children.

Answer 36

 E. There is often a delay in seeking treatment with these children.
 The features of non-accidental injury are:
o Usually involves younger children
o The injuries do not match the parent’s version of events
o Attendance at the hospital or clinic is often delayed
o Bruises appear to be of different vintages
o Frenal tears are an unusual injury
o 50% of children with NAI have signs of injury on their head or neck.