BDS4 Orthodontics PPs Flashcards
Patient has an anterior crossbite and requires fixed appliance treatment.
Name 4 fluoride supplements you would give pt to prevent decalcification (dose & frequency):
High fluoride toothpaste = 2800ppm (over 10 under 16) or 5000ppmF (16+)
Fluoride varnish 22600ppm 4x yearly
Fluoride MW 225ppmF 1x daily
Fluoride tablets 1mg 1x daily
Patient has an anterior crossbite and requires fixed appliance treatment.
Name methods, other than fluoride, to prevent decalcification:
- Good case selection
- OHI
- Diet advice
- Regular appointments at GDP
Patient has an anterior crossbite and requires fixed appliance treatment.
List 8 potential problems associated with fixed appliances other than decalcification
- Root resorption
- Gingival recession
- Relapse
- Loss of vitality
- Mucosal irritation
- Loss of periodontal support
- Wear of adjacent teeth
- TMD risk
Patient is 30 years old & concerned with his Class III incisor relationship.
How would you assess patients skeletal AP relationship?
- Visually (with frankfort place parallel to floor)
- Palpate skeletal bases
- Lateral cephalometry
Patient is 30 years old & concerned with his Class III incisor relationship.
What are the classes of AP relationships?
Class I = maxilla 2-3mm in front of mandible (ANB 2-4)
Class II = maxilla more then 2-3mm in front of mandible (AND >4)
Class III = mandible in front of maxilla (ANB <2)
Patient is 30 years old & concerned with his Class III incisor relationship.
What systemic condition may the patient have if his mandible continues to grow?
Acromegaly
Patient attends with an anterior crossbite involving tooth 21.
When is the best time to begin treatment?
Intercept as soon as it is detected
Patient attends with an anterior crossbite involving tooth 21.
What 3 features of the malocclusion would make it amenable to treat with a URA?
- Only moving 1 tooth at a time
- Tooth in crossbite palatally tipped
- Mild overbite to aid stability and prevent relapse
- Adequate space to move tooth forward
Patient attends with an anterior crossbite involving tooth 21.
Design a URA to fix anterior crossbite?
A = z-spring on 21 0.5mm HSSW
R = adams clasp 16, 26 0.7mm HSSW
A = fine
B = self cure PMMA with posterior bite plane
What 4 factors make early loss of primary teeth worse?
- Age of patient (if lost earlier, more effect)
- Crowding of arch
- More space lost in maxilla > mandible
- Losing Es more space lost than Ds
When might you consider balancing a primary tooth extraction?
Balancing = XLA of same tooth in same arch from opposite side
- Balance primary canines to prevent centreline shift
- Consider balancing lower Ds if crowded
Give 4 reasons for an unerupted central incisor:
- Supernumerary
- Trauma to A [dilaceration]
- Crowding
- Pathology [dentigerous cysts]
What are the dental features in a Class II Div 1 patient?
- proclined upper incisors
- increased OJ
- class II molars & canines
What soft tissue problems are associated with Class II Div 1 malocclusions?
- Incompetent lips
- Lip trap
- Tongue thrust
- Inability to achieve anterior oral seal
What are the 6 features of a twin block appliance?
- Upper bite block
- Lower bite block
- Can have an expansion screw to widen maxilla
- Labial bow anteriorly
- Adams clasps on posterior teeth
- Deterrent rake can be added
Patient has a class III malocclusion.
What is dentoalveolar compensation?
Body attempts to maintain normal inter-arch relationship
- retroclined lowers
- proclined uppers
What is mandibular displacement on closing?
Discrepancy between arch widths meaning upper and lower teeth meet cusp to cusp, so the mandible slides/deviates to one side to achieve ICP
Why do you need to correct a mandibular displacement?
- can cause TMD
- associated with tooth wear
- facial asymmetry
- teeth continue to erupt in displaced ICP position
What 4 methods can be used to stop a digit-sucking habit?
- Positive reinforcement
- Plasters on fingers/bad tasting nail varnish
- URA habit breaker
- Fixed habit breaker
What are the general health implications of cleft lip & palate?
- Hearing problems (otitis media +/- effusion)
- Feeding difficulties in children
- Speech issues
- Mastication issues
- Poor aesthetics
- Increased infection risk
What are the dental features of cleft lip & palate?
- Hypodontia
- Impacted teeth
- Crowding
- Class III malocclusion
- High vaulted & narrow palate
- Increased caries risk
Outline the 5 treatment stages for CLP patients:
3 months = lip closure
6-12 months = palate closure
8-10 years = expansion/alveolar bone graft
12-15 years = definitive ortho
18-20 years = orthognathic surgery
Name 5 members of MDT for a CLP patient:
- GDP
- Maxfax surgeon
- Cleft nurse
- ENT
- Speech therapist
Give 2 ways of expanding the maxillary arch:
- Quadhelix
- URA with mid-palatal screw
How do infra-occluded teeth appear clinically and radiographically?
Clinically = metallic percussion sound, occlusal surface sits low to adjacent teeth, no physiological mobility.
Radiographically = loss of lamina dura uniformity, loss of PDL, external root resorption sometimes seen
What factors determine the management of an infra-occluded tooth?
- Presence/absence of permanent successor
- Degree of infra-occlusion
Give 4 methods of anchorage:
- TADs (non osseointegrating mini screws)
- Nance palatal arch
- Transpalatal arch
- Baseplate
What is leeway space?
The extra mesial-buccal-distal space occupied by the primary molars which are wider than the permanent premolars that will replace them allows space for premolars and molars
- 1.5mm per side (maxilla)
- 2.5mm per side (lower)
How is vertical skeletal relationship measured & give values:
FMPA angle:
- Measure frankfort plane [lower orbit to external acoustic meatus] and mandibular plane [lower border of mandible]
- Average 27
- Meet before occiput = increased
- Meet behind occiput = decreased
UAFH:LAFH:
- 50:50 clinical average
- Measure glabella to subnasale to menton
Define overjet:
The overlap of the teeth in horizontal dimension
Define overbite:
Vertical overlap of the incisors
- 1/2 or 1/3 average
Name 5 active components found on URAs, state their measurements & uses:
- Palatal Finger Spring: 0.5mm HSSW, with ID tubing, used to retract teeth
- Buccal Canine Retractor: 0.5mm HSSW, used to retract canines into line of arch
- Z-spring: 0.5mm HSSW, used to correct anterior crossbites [move teeth labially]
- Mid-Palatal Screw: incorporated into base plate, used to expand arch
- Roberts Retractor: 0.5mm HSSW, reduces overjet
Give 2 baseplate modifications:
FABP: OJ + 3mm, used to correct overjet
PBP: allows disclusion for cross bite alteration
Give treatment options for an impacted FPM:
- Monitor as most disimpact on their own
- Distal discing of E
- Separator placement
- XLE of E and space maintain
- URA to move molar posteriorly
Why might a FPM be impacted?
- Path/angle of eruption wrong
- Ectopic crypt
- Altered E morphology
- Small maxilla
- Excessive crowding
What features of normal development should prevent crowding of the permanent dentition?
- Spacing between primary teeth
- Permanent incisors erupt in proclined manner
- Growth of maxilla and mandible to facilitate space
A pt presents with dilaceration of their 11, describe how you would orthodontically reposition the 11 into the line of the arch. What 4 risks are associated with this?
- Make space for tooth using URA or fixed appliance therapy
- One space has been created you can choose to wait & monitor to see if spontenous eruption occurs
- Surgically expose tooth via closed exposure and gold chain attached to incisor
- Apply traction to the tooth to bring into line of arch
- tooth fails to erupt or move
- ankylosis of 11
- external root resorption
4, excessive dilaceration results in poor gingival aesthetics
A pt presents with dilaceration of their 11, Give 3 indications for extraction of tooth 11.
- Pt doesn’t want surgery or excessive ortho tx
- Unerupted tooth fails to move or respond to ortho traction
- Severe dilaceration so not possible to align tooth within bone
11 is dilacerated, what risks are associated with removal of the unerupted 11?
- damage to adjacent teeth/tooth roots
- loss of space in arch if not correctly managed
- loss of alveolar bone in area may complicate future prothesis
Give 4 indications for the autotransplantation of an ectopic canine:
- Pt unwilling to wear orthodontic appliances
- Degree of malposition is too great
- Pt has adequate space for autotransplantation
- Pt wants a quick fix solution
What 2 risks should you warn patients regarding autotransplantation:
- ankylosis of tooth
- tooth becomes non-vital
Give 3 factors that indicate that a canine cannot be aligned:
- Canine crosses the midline
- Canine placed apically
- No space for canine to move into
What 4 dental abnormalities can be detected by 6 years of age?
- MIH
- Hypodontia
- AI
- DI
When do the first permanent molars begin to calcify?
Calcification begins at birth
When do the third molars begin to calcify?
between 7-10 years old
When do third molars erupt?
17-25 years old
By what age have all the primary teeth erupted?
by 3 y/o
Give the order of eruption of primary teeth:
ABDCE
At what age have all the permanent teeth erupted?
(not including third molars) Approx 12-13 y/o
Give the order of eruption for all the MAXILLARY permanent teeth, including approximate ages:
6s = 6 years
1s = 6/7 years
2s = 8 years
4s = 10/11 years
5s = 10/12 years
3s = 11/12 years
7s = 12/13 years
Give the order of eruption for all the MANDIBULAR permanent teeth, including approximate ages:
6s = 6 years
1s = 6/7 years
2s = 7/8 years
3s = 9/10 years
4s = 10/12 years
5s = 11/12 years
7s = 12/13 years
What is interceptive orthodontics?
Any procedure aimed at reducing or eliminating the severity of a developing malocclusion
What are 3 risks associated with anterior crossbites?
- Tooth wear
- Gingival recession
- Displacement on closure
What are the indications for favourable interceptive treatment of an anterior crossbite?
- Tooth is palatally tipped
- Good overbite as this will aid stability
- Adequate space to move forward
What are 3 risks associated with a posterior crossbite?
- Displacement on closure
- Tooth wear
- Facial asymmetry
Give 3 methods for managing a posterior crossbite?
- URA with mid palatal screw
- Fixed with Quadhelix
- Rapid Maxillary Expansion
What are 4 aetiological reasons for an increased overjet?
- Class 2 skeletal base
- Lower lip trap
- Hyperactive lower lip
- Upper incisor proclination due to digit sucking habit
What are four risks associated with a reverse overjet?
- Displacement on closure
- Incisal edge wear
- Difficulty eating
- Speech problems
What is the main goal of a URA in interceptive treatment of a deep overbite?
- FABP discludes posterior molars
- Allows lower molars to experience continued eruption
Describe the way in which a digit sucking habit produces a malocclusion:
- Prevention of eruption of incisors
- Labio-lingual pressure on incisors
- Tongue position lowered
- Unopposed buccinator pressure on upper arch
What is the biggest complaint for an upper midline diastema?
Aesthetic concerns
What are 4 aetiological factors of an upper midline diastema?
- Growth pattern of teeth/developmental
- Supernumeraries causing displacement
- Low frenum attachment
- Generalised spacing
What is the effect of early loss of As and Bs, what treatment would you provide?
- Minimal effect on centreline
- Don’t balance or compensate
What is the effect of early loss of Cs, what treatment would you provide?
- Can cause midline shift
- Consider balance to maintain centreline in crowded dentition
- Do not compensate
What is the effect of early loss of Ds and Es, what treatment would you provide?
- Severe space loss especially in upper
- Consider space maintainer
- No effect on centreline so do not balance
What occurs if FPMs are lost too early?
Distal migration of second premolar
