Orthodontics past papers Flashcards
Q1 A child presents with the upper left permanent centra incisor in crossbite - a) when is the ideal time to treat this type of malocclusion?
As soon as the problem has been detected
A child presents with the upper left permanent central incisor in crossbite - b) list three features of this particular malocclusion that would make it favourable for treatment with a removable appliance
- tooth in cross bite being palatally tipped
-correct cross bite (bodily movement not required) - a significant/good overbite to aid stability post treatment
- adequate space to move teeth into line of arch
Q1 A child presents with the upper left permanent central incisor in crossbite - c) thinking about removable appliance design for the above clinical situation, please provide the correct details for each of the following (wire sizes and description of component necessary for full mark)
Aim - please construct a URA to correct an anterior crossbite on the 21
A - Active component: 21 z-spring; 0.5mm HSSW
R - Retention: Adams clasp on 54 + 64; 0.6mm HSSW and 16 + 26; 0.7mm HSSW
A - Anchorage: achieved as only moving one tooth
B - Self cure PMMA and posterior bite plane
Q1 A child presents with the upper left permanent central incisor in cross bite - d) give an alternative active component to one you gave before
Flapper spring
Q2 A 12 year old girl presents to you with developmentally absent upper lateral incisors, second premolars and third molars -
a) what clinical term describes this condition
Hypodontia
Q2 A 12 year old girl presents to you with developmentally absent upper lateral incisors, second premolars and third molars -
b) the girl is very concerned about the aesthetics of her upper anterior teeth. Outline two potential treatment options
- Accept and monitor
- Restorative alone - composite bonding, veneers
- Orthodontics alone
- Orthodontics and restorative: space closure and restorative to alter tooth shape
- space opening and bridge, implant, fixed or removable pros or autotransplantation
Q2 A 12 year old girl presents to you with developmentally absent upper lateral incisors, second premolars and third molars -
c) list two syndromes associated with missing teeth (2 marks)
- ectodermal dysplasia
- cleft lip palate
- down’s syndrome
Q2 A 12 year old girl presents to you with developmentally absent upper lateral incisors, second premolars and third molars -
d) you decide to refer the girl to the multidisciplinary team. List three of the specialties that should ideally be represented on the team
- Orthodontist
- Restorative dentist
- Paediatric dentist
Q2 A 12 year old girl presents to you with developmentally absent upper lateral incisors, second premolars and third molars -
Fill in the blanks to complete the following sentence
With regard to developmentally absent teeth in the general population; less than 1% have missing (blank) teeth and less than 6% have missing (blank) teeth
- deciduous
- permanent
Q3 - what is a supernumerary tooth
a tooth or tooth-like entity which is additional to the normal series
Q3 - in which part of the mouth do most supernumerary teeth occur?
most common in anterior maxilla
Q3 - supernumerary teeth can be classified according to their position and/or shape. Please list and describe four different morphological types of supernumerary teeth you know of
Conical - small peg shaped teeth close to midline. They tend not to prevent eruption but may displace adjacent teeth
Tuberculate - paired, barrel shaped that tend not to erupt. They are one of the main causes of failure of eruption of permanent upper incisors
Supplemental - extra tooth/teeth of normal morphology, often an upper lateral incisor or lower incisor but can be third premolars or fourth molars
odontome - can be compound (discreet denticles) or complex (disorganised mass of dentine, pulp and enamel)
Q3- What effects can supernumerary teeth have upon the permanent dentition
- failure of eruption
- displacement - midline diastemas
- crowding
- cyst formation
- root resorption of surrounding teeth
- occasionally (usually conical) can have no effect on dentition
Q4 - A 9 year old presents and you discover that they have a persistent thumb sucking habit - what occlusal changes might you see
- proclined upper incisors
- retroclined lower incisors
- localised anterior open bite or incomplete open bite
- narrow upper arch with or without unilateral posterior crossbite
Q4 - A 9 year old presents and you discover that they have a persistent thumb sucking habit - what is the british shandards institute (BSI) definition of a Class II div 1 incisor relationship
The lower incisor edges lie posterior to the cingulum plateau of the upper incisors. The upper incisors are proclined or of average inclination and there is an increase in overjet
Q4 - A 9 year old presents and you discover that they have a persistent thumb sucking habit - a patient wears a twin-block appliance for 9 months and their overjet is reduced from 10mm to 2mm. List 6 possible changed that functional appliances can produce to allow this
- Distal movement of maxillary dentition
- mesial movement of mandibular dentition
- retroclination of upper incisors
- proclination of lower incisors
- minor skeletal changes of 1-2mm by mandibular growth and maxillary constraint
Q5 List two ways that a skeletal base relationship may be assessed clinically in the anteroposterior plane
- visualisation
- palpate skeletal base (hard tissues)
Q5 what description below best fits a class 1 skeletal base
- the mandible is retruded to the maxilla
- the mandible is 2-3mm posterior to the maxilla
- the mandible is protruded relative to the maxilla
- the mandible is 2-3mm anterior to the maxilla
- the mandible is 2-3mm posterior to the maxilla in class I
Q5 Cephalometric analysis reveals that a patient has an ANB angle of 8 degrees. What does this suggest about their skeletal pattern?
- Class II skeletal pattern
Q5 - List two ways that the skeletal pattern can be assessed clinically in the vertical plane
- FMPA (Frankfort mandibular plane angle)
- anterior face height proportion (LAFH/TAFH)
Q5 What is meant by a class III incisor relationship?
the lower incisor edges lie anterior to the cingulum plateau of the upper incisors. The overjet is reduced or reversed
Q5 what is a balancing extraction and why might you consider a balancing extraction
- the extraction of a tooth from the opposite quadrant of the same arch with the aim to minimise midline shift
- early unilateral loss of deciduous canine in a crowded arch or loss of permanent first molar in a lower crowded arch
Q6 - A Patient is 30 years old and is worried about his class III incisor relationship - how would you assess the patients skeletal anterior-posterior
- visualisation
- palpate hard tissues of skeletal base
- Lateral cephalometry analysis (SNA-SNB = ANB)
Q6 - A Patient is 30 years old and is worried about his class III incisor relationship - what are the classes of AP relationship
> Class I - the maxilla is 2-3mm anterior to the mandible and has an ANB of 2-4 degrees
Class II - the maxilla is more than 2-3mm anterior to the mandible and the ANB is greater than 4 degrees
Class III - the maxilla is less than 2 degrees anterior to mandible (or mandible is anterior to maxilla) and the ANB is less than 2 degrees
Q6 - A Patient is 30 years old and is worried about his class III incisor relationship - name four special investigations an orthodontist would do
- Radiograph - OPT, lateral ceph
- clinical photographs
- study models
- sensibility testing
Q6 - A Patient is 30 years old and is worried about his class III incisor relationship - describe a class III incisor relationship
the lower incisor edge occludes anterior to the cingulum plateau of the upper anterior incisors and there is a reduced or reversed overjet
Q6 - A Patient is 30 years old and is worried about his class III incisor relationship - name 4 intra-oral features that this patient may have
- maxilla is often crowded with mandible being aligned or spaced
- class III molar relationship
- anterior cross bite
- buccal crossbite
- proclined upper incisors and retroclined lower incisors
Q6 - A Patient is 30 years old and is worried about his class III incisor relationship - what systemic condition might the patient have if his mandible keeps growing
- Acromegaly
Q6 - A Patient is 30 years old and is worried about his class III incisor relationship - how is a class III malocclusion managed?
- Accept and monitor in mild cases where pt has no concern and there is no dental health indication
- Intercept early with URA - early correction of incisor relationship
- Growth modification - functional appliance/head gear/ TAD’s
- Camouflage - accept underlying skeletal relationship and correct incisors to class I
- Combined orthognathic and orthodontic Tx - functional/masticatory/profile concerns
Q7 Give 3 uses of a URA, other than tipping and tilting teeth
- movements of blocks of teeth
- Correcting overbites, crossbites and overjet’s
- Expanding the arch
Q7 - Write a prescription for a URA to reduce a 6mm OJ, 1st premolar have been extracted and previous URA retracted canines and reduced the overbite. Pt is in permanent dentition
Aim - please construct a URA to correct the 6mm overjet
On prescription - cross out the first pre molars
A - active component is 22, 21, 11 and 12 Roberts retractor 0.5mm HSSW + 0.5mm ID tubing. Stops - 13 and 23; mesial stops 0.7mm flattened HSSW
R - retention: 16 and 26 adams clasps; 0.7mm HSSW
A -
B - self cure PMMA and flat anterior bite plane (overjet + 3mm)
Q7 - what instructions would you give to a pt on delivery of a URA
- Appliance will feel big and bulky (this is normal and they should get used to it quickly)
- May cause initial excessive salivation (this will pass in 24 hours)
- May impinge speech for a short period of time - practice talking and reading a book aloud and this will subside
- May cause initial discomfort or ache - this is perfectly normal and indicates that the appliance is working
- Must be worn 24/7 including meal times and sleep
- Remove after every meal and clean with a soft brush
- Remove and store in a protective container when participating in contact or active sports
- Avoid hard or sticky foods that may damage the appliance and be cautious with hot food and drinks
- Missing appointments and non=compliance will significantly lengthen the treatment time
- Provide emergency contact details in case of any problems