4. .
It is a common consequence and side effect of
orthodontic movement.
It is found that there are several predisposing
factors, therefore an evaluation of these factors
should be done by careful examination of
personal medical history, dental health, habits
and genetics
5. In orthodontics, induced inflammatory root
resorption is a form of pathologic root
resorption related to the removal of hyalinized
areas of the periodontal ligament following
the application of orthodontic forces and is
considered an undesirable but unavoidable
iatrogenic consequence of orthodontic treatment
.
6. However, as the process of root resorption
during orthodontic treatment is usually
smooth and ends when the force is removed .
7. CLASSIFICATION OF ROOT
RESORPTION •
ACCORDING TO TYPE
Physiologic root resorption
occurring on deciduous teeth
during eruption of permanent teeth
Pathologic root resorption occurring
on permanent roots •
ACCORDING TO LOCATION
Internal root resorption ,
External root resorption.
8. • Surface resorption occurs commonly
periapically as micro defects on the root surface
and stops when the instigating agent is removed and there is
repair of cementum.
• Inflammatory resorption Occurs when
root resorption progresses into the
dentinal tubules to reach the pulpal tissue.
• Replacement resorption Produces ankylosis
of a tooth because bone
replaces the resorbed bone
substance.
inflammation -> osteoclastic
activity -> fusion between
bone and root surface
ACCORDING TO SEVERITY
9. Orthodontic tooth movement is based on force-
induced periodontal ligament and alveolar bone
remodeling (Abuabara, 2007).
So, orthodontic forces represent a physical
agent capable of inducing
inflammatory reaction
in the periodontium
(Giannopoulou et al., 2008).
2-How root resorption begins?
10.
When a tooth moves, a necrosis of periodontal ligament on
the pressure side with formation of a cell-free hyaline zone
occurs..
11. This event is followed by osteoclast resorption of
the neighbouring alveolar bone and bone apposition
by osteoblasts on the tension side (Abuabara, 2007).
The resorption process of dental hard tissues seems to
be triggered by the activity of some cytokines as well as
that of bone. Immune cells migrate out of the capillaries
in the periodontal ligament and interact with locally
residing cells by elaborating a large array of signal
molecules (Jäger et al., 2005)
According Consolaro et al.
(2011), the causes of root
resorption should be
related to the loss of
root surface cementoblasts
12.
Determining the cause of root resorption requires
a thorough history, rescuing the previous
dental history, addiction, accidentes, previous
treatment, associated diseases and other
details relevant to pathogenesis, but not always
remembered by patients and identified by
orthodontists
3. Etiology of root resorption
13.
Several authors have pointed out that
the multifactor etiology of root resorption
is complex, but the condition appears to
result from a combination of individual
biologic variability, genetic predisposition
and the effect of mechanical factors (Bartley
et al., 2011; Weltman et al., 2010; Zahrowski
& Jeske, 2011).
16.
The ideal force for tooth movement would
mimic a physiologic balance between tooth
movement and bony adaptation
The optimal force level for tooth movement
between 7 and 26 g per square centimeter.
When force exceeded this threshold, root
resorption occurs
Orthodontic treatment-related
factors
17. When pressure decreases below this limit, root
resorption ceases (Owman Moll et al., 1996).
King and Fischlschweiger (1982), find that light
forces produced insignificant root resorption,
whereas intermediate or heavy forces resulted in
substantial crater formation
18. In this context, several aspects have been related
to induce root resorption during orthodontic
treatment.
This aspects are as follows:
Treatment duration
Magnitude of the applied forces
Direction of tooth movement
Amount of apical displacement
Force application method (continuous vs. intermittent)
Type of appliance
Treatment technique
19.
In a study, Acar et al. (1999) compared a 100-g
force with elastics in either an interrupted (12
hours per day) or a continuous (24 hours
per day) application. Group who has teeth
experiencing orthodontic movement had
significantly more root resorption than the
control group. Besides that, continuous force
produced significantly more root resorption
than discontinuous force application.
Treatment duration, force application
method and magnitude of the applied forces
20. Orthodontic force leads to micro trauma of
periodontal ligaments and activation of inflammation
related cells . According to some researches there
was no root resorption difference detected while using
low and high forces (50 g and 200 g).
According to Schwartz,forces increasing 20-26 g/cm 2
, cause periodontal ischemia, which may lead to root
resorption .
When orthodontic force decreases to less than 20-26
g/cm 2 tooth root resorption stops.
Orthodontic force
21.
22. Optimal force for orthodontic tooth movement but not
causing root resorption should be 7-26 g/cm 2 on root
surface area
. It was established that intermittent force causes root
resorption more rarely than the continuous force
because the intermittent force protects from formation
of hyalinized areas or it allows reorganization of
hyalinized periodontal ligaments and restoration of
blood circulation at the time, when forces are not
active.
Continuous force leaves no time to repair of
damaged blood vessels and other periodontal tissues
and this may lead to higher level of root resorption
23. Most studies agree that the risk and severity of
external apical root resorption increases as the
duration of orthodontic treatment increases.
Sameshima and Sinclair looked at a sample of
868 patients collected from 6 different specialist
practitioners and found longer treatment times to
be significantly associated with increased root
resorption for maxillary central incisors.
The reasons for the longer duration in treatment
may also have had an influence on the increased
levels of root resorption seen in these patients.
Duration
24. Evaluating the direction of tooth movement
(intrusive vs. extrusive force),
Han et al. (2005) found that root resorption
from extrusive force was not significantly
different from the control group.
Intrusive force significantly increased the
percentage of resorbed root area .
Direction of tooth movement
25. In orthodontics, total apical displacement might
represent a better marker for overall treatment
activation. A tooth that is moved greater distances
through bone is subjected to longer durations of
activation. There is no way to move a tooth between two
points with fixed appliances, without causing
hyalinization.
In 2005, Fox also found that treatment-related root
resorption is correlated with the distance the apex
moves and the length of time the treatment took.
Amount of apical displacement
26. Mandall et al. (2006) compared 3 orthodontic
archwire sequences in terms of:
(1) patient discomfort(2) root resorption, and (3) time
to working archwire.
In that study, all patients were treated with
maxillary and mandibular preadjusted edgewise
appliances (0.022-in slot), and all archwires were
manufactured by the same manufacturer.
The results showed that there was no statistically
significant difference between archwire sequences,
for maxillary left central incisor root resorption
Archwire sequence
27. Root resorption most often occurs in the apical
part of the root, because forces are concentrated
at the root apex because orthodontic tooth
movement is never entirely translatory and the
fulcrum is usually occlusal to the apical part of
the root; periodontal ligaments are situated in
different directions in the apical part of the tooth
root
Tooth structure.(Biological factors)
28. Fixed appliances have been shown to cause more root
resorption than removable appliances which can be
explained by the increased range of tooth movement
afforded by fixed
appliances .
The risk of root resorption associated with different
bracket designs has Yielded In conclusive results
Type of appliance
29. Brin et al. (2003) examined the effect of 2-
phase vs 1-phase Class II treatment on the
incidence and severity of root resorption.
The results showed that children treated in
2 phases with a bionator followed by fixed
appliances had the fewest incisors with
moderate to severe root resorption, whereas
children treated in 1 phase with fixed
appliances had the most resorption. However,
the difference was not statistically significant.
Treatment technique
30.
Linge suggested that the use of inter maxillary
elastics increased the amount of root
resorption but Sameshima and Sinclair did
not find any correlation.
No difference has been found between the use
of sectional and continuous mechanics.
It is generally agreed that the use of rapid
maxillary expanders is associated with
increased levels of root resorption.
Treatment Mechanics
31. Possible a previous history of root resorption
Tooth/root morphology, length and roots with
developmental abnormalities
Genetic influences , systemic factors, including
drugs hormone deficiency, hypothyroidism ,
asthma, proximity of root to cortical bone , alveolar
bone density,
Previous Trauma, endodontic treatment , severity
and type of malocclusion patient age
Patient-related risk factors
32. Nishioka et al. (2006) determined whether there
is an association between excessive root resorption
and immune system factors.
The prevalence of root resorption found was 10.3%.
Allergy, abnormalities in root morphology and
asthma showed be high risk factors for the
development of excessive root resorption during
orthodontic tooth movement.
Systemic factors
33. Some teeth are more susceptible to root resorption,
other – less. According to the research data teeth of the
maxillary teeth are more sensitive to root resorption
than the mandibular teeth and anterior teeth are more
susceptible to root resorption relative to posterior
teeth .
Maxillary incisors are the teeth most affected by root
resorption, because the degree of root resorption is
correlated with the distance of the apex of an incisor
moves and the length of time of the orthodontic
treatment . Other researches have shown that root
resorption is more common in mandibular incisors
Specific tooth vulnerability to root resorption.
34. Case report
25-year-old male patient sought orthodontic treatment after
being subjected to a four-year therapy, as revealed by .
Although he had most roots with severe resorption
No teeth should have been extracted or submitted to
endodontic procedures. Nevertheless, three maxillary incisors
underwent endodontic treatment which, in fact, does not
affect root prognosis.
35.
Dental pulp does not influence external resorption
Similarly, intracanal dressing does not interfere in the cause of
resorptive processes while active forces remain
36. after four years of orthodontic treatment.
Apparently, teeth have no bone or alveolar
cortical bone support; however, periapical
radiograph reveals detailed root and bone
structures involved in the resorption
process.
Severe inflammatory root resorption
revealed by 3Dtomographic scans that allow a
contextual and comparative as-sessment of the
process in each tooth and thei respective
surfaces
37. During the first appointment, after four years of previous
orthodontic treatment, patient’s teeth did not show increased
mobility. Occlusion assessment revealed absence of incisal
guidance and Class III relationship between canines and molars
38. As stated by the patient, there was an ongoing attempt to
correct Class III by means of elastics: Intermittent forces such as
those exerted by intermaxillary elastics might favor root
resorption during orthodontic treatment.
Considering the severity of root resorption and the
conditions of remnant cervical root (responsible for 60% of
periodontal support)
39. Procedures must be followed:
1 st - Teeth can remain in function and esthetics for an
indefinite period of time without endodontic treatment,
except for cases in which endodontic therapy is
exclusively required.
2 nd - Occlusion must be thoroughly balanced without
further interference. Should there be any type of
interference they must be immediately corrected.
3 rd- The patient should be advised to use a
mouthpiece while practicing sports. In the event of a
trauma occurs,
clinicians should follow the same procedure employed
for teeth without root shortening.
40. 4 th - Making patients aware that while eating, they should avoid
grasping hard food, such as some fruit or bread, with their teeth,
only.
5 th - In cases of bruxism, even if mild and occasional, the
patient should ideally, routinely and methodically use
individual acrylic plates while sleeping.
6 th - Since roots are too short, tooth movement should be
avoided.
7 th - Should movement be exclusively orthopedic without
involving compromised teeth and their anchorage, the
periodontal ligament is not affected by inflammation or stress.
In other words, orthopedic movement does not induce a new
cycle of root resorption.
41. 8 th - Chronic inflammatory periodontal disease
associated with dental plaque must be prevented by
properly advising the patient about oral hygiene. Minor
cervical bone loss is utterly significant.
9 th - Fully or partially unerupted teeth must be
extracted, especially if they are too near other teeth
which might not only lead to root resorption, but
also hinder the case due to orthodontic reasons.
10 th - Parafunctional habits, such as onychophagia,
object grasping with teeth, labial or lingual piercings,
must be corrected and avoided
42. This case a 20-year-old
female with the chief complaint
of maxillary protruding and
irregularly aligned mandibular
anterior teeth. Her medical
history showed no allergies
or medical problems.
The overbite was +3.0 mm,
and the overjet +3.0 mm.
After extraction of the four first premolars, a multi-bracket
treatment was started..
case report
43. A severe root resorption of the maxillary anterior teeth
was found 12 months after active treatment.
The maxillaryanterior segmental osteotomy was chosen as the
compensatory treatment. The total treatment period was 2
years and 7 months.
The post-retention panoramic radiograph showed no
developmental root resorption
44. . Treatment plan
We established the treatment plan under consideration
to the soft tissue facial profile. The treatment plan was
determined as follows: (1) Extraction of upper and
lower first premolars; (2) Alignment of upper and lower
incisors with standard edgewise appliances and (3)
Retention to achieve stabilization of the improved tooth
alignment and facial esthetics.
45. Treatment progress
After extraction of the four first premolars and mandibular left
third molar, leveling and alignment of teeth were initiated
with a standard edgewise appliance (0.018 in. 0.025 in.).
After 4 months alignment of the maxillary anterior teeth,
each of the maxillary canines was retracted by pre-stretched
elastics using a same round wire (0.016 in. Co–Cr alloy). The
maxillary canine retraction and en masse retraction of the
mandibular arch were almost finished after 12 months of
active treatment (Figs. 1 and 2B).
46. A periapical radiograph and panoramic radiograph were taken to
check the maxillary incisor roots. A severe root resorption of
maxillary central and lateral incisors was found .
Various treatment plans, stop treatment or decrease the treatment
period, take resting and restart the treatment using lower forces,
and maxillary anterior segmental osteotomy to retract maxillary
anterior teeth, were discussed with the patient.
She chose the last one, then the wassmund technique for
anterior maxillary segmental osteotomy was performed.
47. The maxillary incisors were set backward 5 mm and upward 3
mm, respectively, to improve maxillary protrusion. The
maxillo-mandibular fixation was employed for 14 days.
Rigid fixation was employed using two titanium mini-plates in
maxillary. Seven months after surgery, all bands and brackets
were removed. Total treatment period was 2 years and 7
months. The maxillary peg-shaped lateral incisors pose esthetic
problems and restored with resin.
48. The post-retention panoramic and periapical radiograph showed
no developmental root resorption and periodontal bone loss (Figs.
3E and 4D). There were no periodontal pathological signs, and
the patient was symptom-free. The patient was satisfied with
the results of treatment.
49.
CLINICAL CASE REPORT
A 17-year-old female patient whose chief complaint
was the presence of diastemas in the maxillary anterior
region, an esthetic and psychological concern that she
described inhibited and limited her interaction with
other people, presented for treatment. She was also con-
cerned about the potential risk of losing some of her
teeth due to general root resorption which had been
previously diagnosed by another orthodontist who had
refused to treat her due to the potential risks involved in
trying to close the spaces.
50. The patient presented a straight profile, good health condition
and oral hygiene, normal breathing pattern and atypical
swallowing pattern (Fig 1). Intraoral examination revealed
Class I malocclusion, 2-mm overjet and 5% overbite, coinciding
dental midlines, moderate spacing in both arches and upper and
lower labialized and protruded incisors (Figs 1 and 2)
51. Radiographic analysis
Revealed the presence of all teeth which exhibited altered crown-root
proportion, (maxillary right permanent lateral incisor, mandibular right first
and second premolars) with thinned and short roots, sclerosis of root canals
and complete root resorption
of maxillary permanent left
lateral incisor. Tooth buds of
maxillary and mandibular left
third molars at Nolla Stage 6
development were
observed, as well as the presence
of mandibular second
primary molar with congenital
absence of mandibular left
second premolar and mandibular
right third molar
(Fig 3)
52. TREATMENT OBJECTIVES
The aim of orthodontic treatment was mainly to meet patient’s
esthetic expectations, achieve closure of anterior diastemas with
light forces and also maintenance of crown-root proportion.
TREATMENT ALTERNATIVES
Treatment options for this patient were limited due to her dental
characteristics and malocclusion.
At first orthodontic treatment was not an option, but the patient
was highly concerned about esthetics. Another option was not
using Orthodontics to fully close diastemas between maxillary
teeth, but distributing those spaces to be restored with
composites instead, so as to increase mesiodistal width, and also
restore with osseointegrated implants the absent premolar and
maxillary permanent left lateral incisor. Nevertheless, the
patient did not count with the economic resources for this
treatment option. Thus, it was decided to start orthodontic
treatment focused on fully closing diastemas with light
forces. The patient agreed and understood the risks
53. TREATMENT PROGRESS
Prior to treatment onset, the patient was informed about the characteristics of
the progressive pulp pathology condition she had and the limitations, risks
and objectives of treatment
Treatment plan required initial consultation with an endodontist in order to
evaluate the degree and severity of external root resorption and begin
orthodontic treatment with minimal risk, while taking into account the
existing limitations.
Orthodontic treatment initiated first in the upper posterior segments
between canines and molars with an edgewise-standard technique.
During the first phase of treatment, low caliber NiTi wires were used (Fig 4).
Once the posterior segments of the maxillary arch were
consolidated, fixed
appliances were installed
in the upper anterior
segment where teeth
were more affected
by re sorption
54. • Space closure in the lower arch was initiated with a frictional technique
using light elastomeric chains. Strict panoramic radiographic control was
carried out every eight months based on clinical criteria in order to
monitor the progression of pulp pathology (Fig 5).
• Given the positive response during treatment, the space between
mandibular first premolar and molar was closed by
attraction with a closed loop which had a tip back bend
on the molar in order to protract and disincline it (Fig 4).
55. TREATMENT RESULTS
After orthodontic treatment with fixed appliances, the shape and contour of
both dental arches improved, the rotations were fixed, diastemas were
closed, pro clination of maxillary and mandibular incisors was improved,
a better occlusal relationship was achieved, overbite and overjet were
corrected, the Curve of Spee was flattened, her nasolabial angle improved and
a harmonic smile was achieved (Figs 6, 7 and 8).
Panoramic and periapical radiographs taken at the end of treatment
revealed that there was no significant progression of root resorption and the
periodontal condition was acceptable (Fig 8).
56. CONCLUSIONS
1) Orthodontic treatment of patients with idiopathic multiple
root resorption offering them esthetical and physiological
solutions is possible considering that the patient understands
potential risks and limitations.
2) Orthodontic management is based on simple mechanical
techniques that include light and controlled forces, allowing
predictable movements which are physiologically acceptable if
pulp and periodontal limitations are considered.
3) A complete history of patient’s medical background
allows identification of any systemic condition that might be
associated with the pulp pathology.
4) An informed consent form is indispensable and protects the
clinician in case of any legal implication that might arise in these
types of cases.
57.
CLINICAL CASE REPORT
Female patient, aged 10 years, was referred by her pedodontist
for orthodontic treatment. She presented with a slightly convex
profile, good maxillomandibular relationship (Fig 3), Class I
malocclusion, constricted upper and lower arches (Fig 4),
anterior mandibular and maxillary crowding, and mandibular
midline shift (1 mm to the right).
58. Four years earlier, the patient had suffered a fall with total
avulsion of the upper central right and extrusion of the upper
central right (Fig 2, A). According to her pedodontist, both
radiographically and clinically, the teeth had open apices with
divergent walls. Left central upper was repositioned and right
central upper was re implanted (Fig 2, B). A semi-rigid retainer
was bonded and finshing line (nylon) was placed around teeth
upper canin right , upper central right , upper central left ,
upper canin left. Amoxicillin 250 mg was prescribed for 7 days,
Cataflan drops for three days, and aqueous
polyvinylpyrrolidone for cleaning the region. Liquid and semi-
liquid food was recommended
59. Subsequently, upper central left underwent endodontic treatment
with calcium hydroxide for root apexification.At the time of the
initial orthodontic examination, upper central left showed signs of
resorption , light browning of the crown and a slight step between
central upper right and lateral upper left. The central upper right
appeared normal both clinically and radiographically (Fig 4, B).
60. The orthodontic plan provided for the use of a standard Bimler
appliance for upper and lower arch expansion and a fixed
orthodontic appliance in a second stage for tooth alignment and
leveling, and occlusion detailing.After nine months of treatment
with the removable appliance, we observed a significant increase
in the size of the step between the central upper left and the
central and lateral upper right due to the ankylosis in central
upper left .We then decided to amputate the crown of central
upper left and to bury the intraosseous root
61. while suspending the use of the removable appliance and
mounting a fixed orthodontic appliance, straight wire Roth
prescription . A pontic was bonded between cental upper left and
lateral upper right and remained in place until the end of the
active orthodontic treatment and retention period .
62. The patient will wait until her growth is completed before
having an implant and prosthesis placed in the edentulous area
.
63. The clinicians should have in mind that
abnormal root morphology may increase the
risk of root resorption.
This is specially valid for pipette-shaped roots.
Maxillary incisors seem to be the teeth most
likely to suffer from EARR.
From the root resorption point of view
orthodontic treatment should begin as early as
possible since there is less risk of root
resorption in young and developing teeth.
Conclusion
64. Light orthodontic forces seem to present a
smaller risk of resorption than heavy forces.
The use of interrupted forces seems to give less
root resoption
If initial resorption is detected, a pause in
treatment of two-three months should be
considered. With sustained quality, treatment
duration should always be as short as possible.
It is very important that the patient is fully
informed that root resorption can be a
consequence of his/her orthodontic treatment
with fixed appliance. than continuous forces.
65. In conclusion, amount of root movement and
presence of long, narrow, and deviated roots
increase the risk for apical root resorption. In
addition, use of elastics may be a risk factor for
the teeth that support the elastics.
A correlation between gender and apical root
resorption has been reported, females are more
susceptible than males
66. Treatment with rectangular archwires plus
intermaxillary elastics and duration of treatment were
significantly related to the severity of root resorption
Only heavy forces responsible for root resorption, but
intensity and duration are also of great importance
Results confirmed hypothesis that type of initial
malocclusion may not be of importance for
amount of apical root resorption during treatment
67. Several authors believe that overjet is a
powerful predictor for resorption.
However, overjet can be corrected in several
ways other than moving the roots of maxillary
anterior teeth, such as growth adaptation in
growing persons, anterior expansion of the
mandibular dentition, and orthognathic
surgery.
Also, appliances may be present for longer
periods without creating pressure on the
teeth.
68.
Final considerations
Teeth with only the cervical third remaining from
orthodontically induced external root resorption must remain
in one’s mouth with function and esthetics preserved.
In these cases, endodontic treatment is not recommended for
affected teeth because the pulp is not involved in the process
and the post-treatment phase of endodontic therapy might be a
complicating factor due to risks of accidental contamination or
filling material overflow.
.
69.
Accurate diagnosis of causes and stages of
development, in addition to occlusal trauma control
and oral hygiene as well as the use of a mouthpiece
to avoid trauma and acrylic plates to correct bruxism
are part of the protocol recommended to treat cases
of extreme root resorption associated with induced
tooth movement.
Additionally, care should be taken with regards to
reading of imaging exams, since tomography does
not accurately reveal minor details of thin cortical
bone and trabeculae
70.
Periapical radiograph, on the otherhand, provides
precise details, especially in terms of detecting
cervical bone and root loss.
Should proper care be taken by clinicians and
patients, the chances of tooth loss in extreme cases of
root resorption associated with induced tooth
movement are reduced