Interceptive orthodontics: the timing of orthodontic treatment Flashcards
Interception
Early identification and management of potential
problems
Avoidance of a worse malocclusion (e.g judicious
extractions)
Early appliance treatment
The orthodontic timetable
- primary dentition
- early mixed dentition
- late mixed dentition
- permanent dentition
For each stage
Normal development
Problems
Minor, interception, treatment
Primary dentition - normal development
Established by 30 months
Positive overjet and overbite
Spacing normal
Primary dentition problems
• Delayed eruption
-not important unless contralateral side different or abnormal sequence of eruption
• Missing teeth
-can indicate missing permanent tooth but not always
-affects <1% of pts
• Supernumerary teeth
-30-35% pts with supernumerary primary tooth will have permanent supernumerary
• Abnormal teeth
-germination: consider extracting early to allow alignment of single permanent tooth
-fusion
• Crowding
-need >6mm spacing in primary dentition
• Overjet
-will probably be > in permanent dentition
-no treatment at this stage: observe
• Class III
-will probably be present in permanent dentition
-no treatment at this stage: observe
• Crossbite
-skeletal crossbites: tend to persist
-dental crossbites: variable
• Caries/trauma
-traum to primary incisor: possible ankylosis
–>look out for deflection of permanent successor
• Habits
-anterior open bite
-unilateral posterior crossbite
-no intervention at this stage
Early mixed dentition
First permanent molar eruption
Upper and lower incisor eruption (lingually)
6/6 U&L often erupt into half-unit class II
-correcting to Cl I in time with the Leeway space (C,D, E wider than 3, 4, 5)
Size discrepancy between primary and permanent incisors
Upper arch -7mm greater Lower arch -5mm greater Permanent teeth more proclined Inter-canine width growth
Early mixed dentition problems
• Delayed eruption -should be referred early -most common cause: supernumerary teeth • Early loss -think about centre lines -little effect with loss of incisor • First permanent molars -if poor prognosis, can refer to ortho for opinion about timing of extraction • Median diastema • Increased overjet -treat now or wait? • Crowding -transverse expansion in lower arch replases -extract primary teeth? • Anterior crossbite -treat early • Posterior crossbite -consider treating early (look for mandibular displacement on closure?) • Habits -thumb/ digit sucking: educate pt and parents and advice cessation of habit • Class III -face mask suitable for some Sk III pts age 8-10 years -refer to ortho specialist
Supernumerary teeth
Erupted mesiodens -extract and align teeth Unerupted supernumerary -XGA supernumerary Supplemental -usually extract most displaced or poorly formed
Premature loss of primary canine e.g. LLC
Shift of centre line to extraction side
-balance loss in either arch
Premature loss of primary first molar e.g. LLD
In crowded cases, loss of LLD can cause sift of lower centre line to left
-consider balancing
Premature loss of primary second molar e.g. ULE
Mesial movement first permanent molars
Space loss > and faster in upper arch
-disrupts occlusion: do not balance
Premature loss of primary teeth
Balancing extractions? Compensating extractions? -over-eruption only temporary -do not compensate in primary dentition Space maintenance?
Space maintainers
Fixed
Removable
Problems of space maintainers
Pts often unsuitable for appliances
Must fit immediately
Often unnecessary
Impacted first permanent molars
Options:
- Disimpact UR6
- Extract E
Causes of median diastema
• Normal - “ugly duckling” -U2112 distally inclined due to position of canine crowns -upper midline diastema • Supernumerary tooth • Generalised spacing • Proclined upper incisors -class II div 1 -digit sucking • Trauma • Pathology (cysts, tumours)
Indications for extractions of primary canines
Permit lateral incisors to align Allow incisor to be moved over bite Potentially to improve position of palatally displaced permanent canines Severe upper and lower crowding Upper laterals palatal/ impacted
Anterior crowding
All primary canines extracted
Upper laterals erupted, lower laterals spontaneously align
Crowding transferred to buccal segments (no space for 3s)
Correct posterior XB
Midline screw
Adams cribs on 6s
-0.7mm diameter stainless steel (retention and anchorage)
Acrylic baseplate (anchorage)
Late mixed dentition problems
• Missing teeth
-monitor/ refer to hospital for Tx jointly with paeds/ RD (multi-disciplinary care)
• Infraoccluded teeth
-monitor then extract under LA (or make timely referral)
• Crowding
-monitor/ refer for formulation of Tx
• Poor quality 6s
-if poor prognosis: can refer to ortho for opinion about timing of extraction
• Ectopic canines
-refer at time of diagnosis
• Habits
-digit-sucking: proclined upper incisors, anterior open bite, unilateral posterior crossbite, > overjet
-educate pt and parent and advise to stop
• Increased overjet
-refer to ortho - functional appliances best during adolescent growth spurt - age 11-13 years
Palpation of maxillary canines
Screen every 9-yo pt bucally
-canine buldge
Radiographs
Refer for ortho specialist opinion if evidence of ectopic position
Habit breaking appliances
Better spontaneous correction of occlusion if stops before 8yo
Passive removable appliance
-3 months full-time
-3 months nights only
“Haryake” passive removable appliance (primarily for correction of AOB)
Problems with adult treatment
• Lack of growth – treatment slower
• Mutilated dentition determining extraction
patterns, reduced periodontal support,
periodontal disease…
• Co-operation can be more difficult – ability to
attend/ willingness to participate
•Different expectations
