Operative dentistry aje qualtrough, jd satterthwaite la morrow, pa brunton

Orthodontic movement
Formal orthodontics may be a useful adjunct, either involving 
movement of individual or multiple teeth (e.g. uprighting molars or
flattening the curve of Spee). However, in many cases localised axial
tooth movement may be simply and easily performed. This method
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Indirect restorations – further considerations


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was first described by Dahl
22,23
, who utilised a removable appliance
that increased load onto selected anterior teeth resulting in axial
movement. The space obtained is a combination of intrusion of the
teeth with the ‘Dahl appliance’ and extrusion of the remaining teeth,
the pattern of movement differs between individual patients, though
age appears to be a factor with intrusion predominating in older
patients
24
.
The technique, often termed the ‘Dahl principle’
25
, has been devel-
oped and techniques involving indirect metal splints cemented onto
teeth
24
and individual restorations (usually resin composite) placed
‘high’ have been described
26
. The use of individual build-ups on 
anterior teeth rather than splinting teeth together may cause splaying
and labial movement, though this does not appear to be a problem in
most cases. Space for restorations needed in a localised area only can
be created, for example by providing interocclusal space anteriorly by
moving all six teeth, and the principle may also be utilised to move
individual teeth, for example to correct over eruption. There is an
increasing trend to cement definitive anterior restorations in ‘high’
and rely on this movement. Although this approach is very con-
venient, this technique offers less control over occlusal relationships
and in many instances it is prudent to create space and then provide
the definitive restorations to an exact and planned occlusal relation-
ship. This technique may be employed posteriorly or anteriorly and is