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
