The Journal
j Treatment Related [Mechanical] Factors
½ Type of orthodontic appliances used
½ Magnitude of applied forces
½ Direction of tooth movement
½ Amount of tooth movement
½ Jiggling and Occlusal trauma
j Combined Factors
½ Treatment duration
½ Root resorption detected radiographically during orthodontic
treatment
½ Root resorption after appliance removal
½ Relapse
Types of appliance used Magnets
Degree of root damage is a function of the
appliance used. Increase in force as space closes with time
(attraction) can stimulate a more physiologic
tissue response, thus decrease the potential for
root resorption.
Fixed versus Removable
Use of fixed appliances is more detrimental to
the roots. Ketcham found that normal function is
disturbed by splinting effect of fixed appliances
over a long period that can cause root
resorption.
Stuteville concluded in his study that jiggling
forces caused by removable appliances are
more harmful to roots.12
Begg versus Edgewise
Light wire Begg technique causes less root
resorption than edgewise. Maxillary incisor root
resorption during the Begg stages has been
documented.
Malmgren et al.
suggested that there is no difference between
these techniques and also found that frequency
of root resorption was signficantly higher (48%)
in traumatized maxillary incisors when intruded
by the Begg technique compared with
edgewise technique (43%).3
44
Rapid Maxillary Expansion
External root structure of 13 and appliance-
attached and 5 unattached maxillary first
premolars from 9 patients have been
investigated with the scanning electron
microscope (SEM).
• All anchor premolars exhibited root resorption
(mostly confined to buccal surface).
• Longer an anchor tooth remained in fixed
retention, more extensive the buccal root
resorption.
• In contrast, Timms and Moss, in a light
microscopic study of RME-induced root
resorption, found that resorption bays were
confined to the mesiobuccal and distobuccal
root surfaces of anchor teeth; buccal root
surfaces were specifically excluded as sites of
resorption.9
Vol. 14 No. 1
Jan-Apr 2018