- A 9-year-old girl attends for a review appointment. Six months ago, her upper left permanent central incisor had not erupted, and it is still not present today. A radiograph reveals the presence of a supernumerary overlying the unerupted tooth. She presents with the following clinical features:
- Class II division 1 incisor relationship
- Overjet of 5 mm
- Increased overbite
- Lingual displacement of the partially erupted lower right lateral incisor (LR2)
- Upper left first permanent molar (UL6) is in crossbite
Which single feature of the child’s dentition would lead you to score a grade 5 in her IOTN?
A A midline supernumerary tooth
B An increased overbite
C An overjet of 5 mm
D Severe crowding of 4 mm associated with the LR2
E UL6 is in crossbite
Answer : A
Delayed eruption of a permanent max incisor tooth can be considered in the following circumstances:
- Eruption of the contralateral incisor occurred >6 months previously
- The maxillary incisors remain unerupted > year after the eruption of mandibular incisors
- There is significant deviation from the normal eruption sequence, eg lat incisors erupting prior to central incisor
2. A 21-year-old female, who is undergoing fixed orthodontic treatment, attends for a routine examination. Her plaque control is particularly poor. Which single most important risk would encourage you to contact the orthodontist to discuss discontinuing treatment?
A Decalcification
B Loss of vitality
C Pericoronitis
D Root resorption
E Tooth mobility
Answer : A.
Some degree of tooth mobility is normal during tx. Other common risks are relapse, root resorption and gingival recession. Pulp necrosis rarely happens, may occurs if rapid and excessive force is applied to teeth which is already compromised.
3. A 12-year-old girl attends for assessment. Her upper right central incisor overlaps the coronal one-third of the lower incisor crown height, and there is contact between the lower incisal edges and the palatal surface of the upper incisors. Which single option best describes the patient’s overbite in this scenario?
A Increased and complete
B Increased and incomplete
C Normal and complete
D Reduced and complete
E Reduced and incomplete
Answer :C
Normal vertical overlap (upper incisors cover 1/3 – 1/2 of lower incisor crown height)
O/b is complete if the edge of lower incisors make contact with upper incisors or palatal mucosa
4. An 11-year-old girl with a posterior crossbite is undergoing orthodontic treatment with a removable appliance. Which single tooth movement would a removable appliance not be able to achieve?
A Bodily movement
B Canine retraction
C Reduction of an increased overbite
D Space maintenance
E Tipping of teeth
Answer : A
5. A 10-year-old boy is undergoing the initial stages of his orthodontic treatment. He has a crossbite and has been provided with a removable appliance in order to expand the maxillary arch. Which single component should be adjusted to achieve the desired movement?
A Acrylic base plate
B Adam’s clasps
C Midline expansion screw
D Offset southend clasp
E Posterior bite plane
Answer :C
6. A 17-year-old woman attends for a routine check-up with her general dental practitioner, having been discharged from her orthodontist following comprehensive orthodontic treatment. She reports that she has lost the instructions for wearing her vacuum-formed retainers. What is the single most appropriate piece of advice to give in this scenario?
A Wear the retainers full-time
B Wear the retainers only during the day and remove for eating/ drinking
C Wear the retainers for 2–3 hours per day
D Wear the retainers only at night
E Wear the retainers only during the day and keep them in if eating/ drinking
Answer : D
Vacuum-formed retainers should be worn every night (12 hours). There is a high risk of relapse if the patient does not consistently wear them. There is a risk of caries and damage to the enamel if food and drinks are consumed whilst wearing the retainers. Only water can be consumed safely.
Recommended to wear retainer at least 12hours everyday for 8 weeks after tx completion. Then, orthodontist will decide if the wear can be reduced to at night only
7. A 9-year-old boy has a Class II skeletal discrepancy and would benefit from a functional appliance. What would be the most ideal age range at which to begin his treatment in order to utilize his pubertal growth spurt?
A 10–11 years
B 12–13 years
C 14–15 years
D 16–17 years
E Over 17 years
Answer : B
Ideal age for use of functional appliance in girls (10-12 years) and boys (12-14 years)
Tx for functional appliance should not start too early, cause pt compliance will lose away with lengthened tx. So, immediately after functional tx (about 9months), FA is provided (18-24 months). If pt bullied, or risk of trauma, then start functional tx earlier