The Journal
Jiggling and occlusal trauma
Jiggling forces causing Occlusal Trauma and
Root Resorption can result from the use of
intermaxillary elastics or active removable
appliances. Occlusal forces on poorly aligned
dental inclined planes can be a contributing
factor in root resorption during orthodontic
treatment. Newman, however, did not found a
relationship between root resorption and
occlusal trauma or heavy occlusal forces.
No orthodontic force can imitate the natural
harmless physiologic force.
Although no
difference in orthodontically induced root
resorption has been found at low and high force
levels (50 g to 200 g), it is still recommended not
to overload teeth with high force levels.
High levels of force will tend to increase
damaged areas in the periodontal ligament,
which may lead to more extensive root
resorption. The literature agrees that jiggling
and movement caused by application of
intermaxillary elastics are two kinds of
movement likely to increase the risk of root
resorption.9,12
Goldin reported that the amount of root loss
during treatment is 0.9 mm/year. Root
resorption detected radiographically during
orthodontic treatment. Minor resorption or an
irregular root contour seen after 6 to 9 months
indicates an increased risk of further root
resorption. No severe resorption is detected at
the end of treatment in teeth after 6 to 9
months.19,20
Root resorption after appliance removal
Clinically, root resorption associated with
orthodontic treatment usually cease once the
active treatment terminated. This is expected
since progressive root resorption is tissue-
pressure related. Remodeling of the sharp,
rough edges of the resorbed root surfaces may
occur.
Reitan claimed that additional active resorption
lasts for about a week after appliance removal
followed by cementum repair that lasts 5 to 6
weeks of orthodontic inactivity. Root resorption
after treatment is mostly related to causes other
than the active treatment itself, such as occlusal
traumatism, active retainers and others.9,10
Combined factors :
Relapse
Treatment Duration
Most studies report that the severity of root
resorption is directly related to treatment
duration. Rudolph reported that 40%, 70%,
80%, and 100% of the patients in treatment
demonstrated some root resorption after 1, 2, 3,
and 7 years of active treatment, respectively.
Levander and Malmgren found
After 6 to 9 months = 34%
End of active treatment (19 months) =
Increased to 56%.
Histologically, 34% and 56% of the examined
teeth showed resorbed lacunae after 15 and 20
days of tooth movement, respectively.
46
If root resorption and loss of crestal alveolar
bone are sequelae of tooth movement under
orthodontic forces, it is probable they also occur
during the tooth movement of relapse. Reitan
claims that forces of relapse are not strong
enough to cause root resorption.
Ten Hoeve and Mulie believe that teeth are
prone to additional root loss during relapse as a
result of light muscle forces. Sharpe et al. found
a higher frequency of root resorption in patients
demonstrating relapse compared with patients
without relapse because of the loss of overall
bone support.
Vol. 14 No. 1
Jan-Apr 2018