This document discusses root resorption during orthodontic treatment. It defines root resorption as the pathological or physiological loss of cementum and dentin. It describes the histopathology of root resorption, noting that it is a form of pathological resorption caused by orthodontic forces that remove hyalinized areas in the periodontium. Factors that can contribute to root resorption during orthodontic treatment include the magnitude, type, and direction of orthodontic forces applied as well as the type of orthodontic appliance used. Patient factors like genetics, age, tooth vitality, and systemic conditions may also influence susceptibility to root resorption.

1. Root resorption and
orthodontic treatment
Prepare by dr Hawa Shoaib

2. Definition
 Root resorption is a pathological and
physiological process that results in the
loss of the cementum and dentine .

4. Histopathology of Root
Resorption
1. Root resorption in orthodontics is referred to as
induced inflammatory resorption, and it is a form of
pathological root resorption, in which orthodontic
forces are transferred to the teeth and hyalinized
areas are thus removed in the periodontal area.
2. During the removal of hyalinized tissues, the
cementum is also removed. The resorption process
is initiated by dentinoclasts. Osteoclast-like cells
referred to as odontoclasts caused resorption. They
have pleomorphic shape and are usually
multinuclear.

5. Etiology of Root Resorption
 Factors related to orthodontic
treatment
 Factors related to the patient

6.  These include 1 genetic factors, 2 chronological age, 3
dental age, gender, 4 ethnic factors, 5 syndromes, 6
psychological stress, 7 increased occlusal force, 8 tooth
vitality, 9 type of teeth, 10 dental invaginations, 11
features of dentoalveolar and facial structures, 12
existing root resorption before treatment, 13 proximity of
the root to the cortical bone, 14 nutrition, 15 systemic
factors (illnesses that cause inflammation, asthma, allergy,
etc.),16 hormonal irregularities, 17 systemic medicine
use, 18 metabolic skeletal disorders, 19 parafunctional
habits, 20 morphology of teeth/root, developmental
abnormalities of roots, properties of cementum
mineralization,21 hypofunction of the periodontium, 13
history of trauma, 14 endodontic treatment, density of the
alveolar bone, and 15 type and severity of malocclusion
and alcoholism.
 Factors related to
the patient

8. Factors related to orthodontic
treatment
 Magnitude of orthodontic force
When increasing force, root resorption also
increases.
Am J Orthod Dentofacial Orthop. 2009 Oct; 136(4):492.e1-9; discussion 492-3.
Paetyangkul et al. concluded that even if a
light force was applied, whenever there is
an increase in the application time, root
resorption also increases.

9.  Type of orthodontic force
 Although it is clinically difficult to apply
intermittent forces in fixed orthodontic
treatment, it has been suggested that
intermittent forces should be preferred
instead of continuous forces to prevent
serious root resorptions

10. Direction of tooth movement
 When compared with intrusive
movements, extrusive movements occur
easily, but they also cause root resorption
in interdental areas in the cervical third of
the root. It has been stated that root
resorption occurs four times more
during intrusion than during extrusion

11. type of orthodontic appliance
 It has also been found that the use of Class
II elastics might be a risk factor for root
resorption.
 Heavy forces during rapid maxillary
expansion might also induce root
resorption in attached premolars and
molars. Further, there are studies that have
found that rapid expansion might induce
root resorption in the unattached second
premolar tooth