Endo ortho interface by DR. JAGADEESH KODITYALA

ENDODONTIC
ORTHODONTIC
INTERFACE
JAGADEESH. K
3rd year MDS

CONTENTS
 Introduction
 Nature of contemporary orthodontic treatment
 Effect of orthodontic tooth movement on the pulp
 Effect of orthodontic tooth movement on root
resorption
 Effect of orthodontic tooth movement on
resorption of vital, non-vital or root treated teeth

 Effect of previous injuries on orthodontically mediated
resorption and tooth movement
 Effect of orthognathic/orthodontic treatment on teeth and
their pulps
 Effect of orthodontic tooth movement on endodontic
treatment and its outcome
 Role off orthodontics in endodontic restorative treatment
planning

Introduction
 Endodontic treatment of teeth is now a common
procedure across all age groups, either as a result
of caries or trauma.
 Furthermore, as the number of adults undergoing
orthodontic treatment increases, the number of
orthodontic patients presenting with root filled
teeth is on the rise.

 There are two major areas where endodontic and
orthodontic interventions share a common ground –
 One is orthodontic treatment affecting the tooth being
moved and some response may be noted in the pulp
tissue
 adult and mutilated cases where orthodontic treatment
is necessary to gain a desirable result when
endodontically involved.

Effect of orthodontic tooth movement on the
pulp
 Orthodontic tooth movement by virtue of direct interruption
and interference with the neurovascular supply and, to a lesser
extent, indirectly by tooth flexure, may affect the pulp
physiology and status.
 Hamilton & Gutmann (1999). The nature, direction and extent
of forces exerted (type of orthodontic technique and its
execution) during tooth movement, their intermittent or
continuous nature, the apical root maturity and age of patient
may all influence pulp changes.

 Tissue level
(pulpal inflammation, pulpal degeneration, cellularity,
fibrotic changes, predentine width, reparative dentine
formation, pulpal space obliteration, Hertwig’s epithelial
root sheath)
 Cellular level
(pulp cell metabolism and cell respiration rate, survival or
degeneration of odontoblasts)

 Vascular level
(vascularity, blood flow, circulatory disturbances,
angiogenesis)
 Neural level
(neuronal cell density, distribution of myelinated versus
non-myelinated cells)

 Molecular level
(expression of various molecular factors including
calcitonin-generelated neuropeptide [CGRP], methionine
encephalin, β-endorphin, substance P, neurokinin A,
vasoactive intestinal polypeptide, neuropeptide Y)
 Clinical level
(pulp response to pulp testing, signs and symptoms,
discoloration, pulpitis, pulp necrosis).

 Teeth with mature apices and those with a history of
trauma or significant caries are at greater risk.
 Teeth with immature roots are likely to be less affected
because of a richer, thicker and less constrained (apical
foramen size) neurovascular bundle.

 Loss of sensation is not an indication for endodontic
treatment
 Laser Doppler Flowmetry
may be the only way to
examine vitality and
determine the need for
endodontic therapy.

 Rita Veberiene et al explained the pulpal vitality in
orthodontic intrusion cases. The intrusive force is applied on
one side of premolars and the contra lateral premolars used
as control.
 Increased neural response and AST activity was observed,
these changes may be due to hypoxia of the pulp during
orthodontic tooth movement

 Yet it does not occur consistently and may be affected by
pulpal status, root morphology and nature and magnitude
of orthodontic forces.
 Small amounts of root resorption, up to 1–2 mm, occur in
the majority of patients undergoing fixed appliance
orthodontic treatment, with little known long-term
implications.
 Approximately 15% of patients may be affected by
greater than 2.5 mm loss of root length, which may have
long-term implications, particularly if it occurs in
conjunction with periodontal bone loss.

 Resorption due to orthodontic tooth movement is
regarded to be either of the surface type or the transient
inflammatory type
 the former being a physiologically adaptive variety and
the latter the same type with superimposed inflammation
mediated by minor injury.

 Such resorption has been said to affect about 40% of
maxillary incisors and almost 20% of mandibular incisors.
The classical radiographic pattern is slight blunting or
rounding of the root apex, sometimes extending to gross
resorption

 Roots with pipette shaped or blunt roots may be more
susceptible to apical resorption
 The risk of severe localized root resorption during
orthodontic treatment appears to be greater for maxillary
incisors, with 3% of teeth affected compared to less than
1% for all other teeth. This risk is increased even further,
up to a 20-fold, if the roots are forced against the palatal
cortical plate during treatment.

 The majority of studies suggest there is no difference in
response between root-treated and vital teeth,
 a slightly smaller number of studies suggest that vital teeth
may resorb to a greater extent than root-treated teeth,
 while a smaller number of studies still suggest that root-
treated teeth resorb to a greater extent than vital teeth.

Endodontically treated teeth undergoes more
resorption than vital teeth
Based on histological studies Steadman was criticized the
root resorption process stated that roots of the root canal
treated teeth acts as a foreign body causing chronic
irritation and root resorption subsequently undergoes
ankylosis which may impede orthodontic tooth movement

Endodontically treated undergoes lesser
resorption than vital teeth
Bender et al suggested that the loss of the release of
neuropeptides from a pulp that has been removed would
result in a decrease of the CGRP-IR (calcitonon gene
related peptide immune reactive) fibers and a reduction in
the amount of resorption seen in endodontically treated
teeth

Endodontically treated teeth and vital teeth
undergoes similiar resorption
Tarraf et al investigated the resorptive activity of
endodontically treated teeth v/s vital teeth through SEM
(scanning electronic microscopic) study and reported
that there no difference in resorptive activity in either
groups

WHAT
HAPPENS
TO FILLING?
MAY BE
LEFT
BEHIND
MAY FORM
A FIBROUS
CAPSULE
MAY FORM
A SINUS
TRACT
MAY BE
REMOVED

In some cases root resorption may take place,
exposing protruded root filling material, the
periodontal ligament Can adapt and develop a new
periodontal space and lamina dura.

 If a root filled tooth has been well cleaned, shaped and
three dimensionally obturated the apical seal would be
maintained irrespective of the amount of resorption.
 However resorption may lead to exposure of dentinal
tubules that may harbor bacterial toxins and necrotic
material that may provide sufficient irritation to induce an
inflammatory response or increased inflammatory root
resorption.

 Desauza et al evaluated the periapical tissue healing of
endodontically treated teeth in dogs. The root canals were
prepared biomechanically and given Ca(OH)2 dressing,
then obturated with seal apex [Ca(OH)2 based sealer] and
gutta-percha points. Later all these teeth were subjected to
orthodontic forces. Finally, after sacrificing all animals the
histological analysis showed a favorable action on
periapical tissue healing and high rate of biological closure
of main and accessary canals by newly formed cementum
with better organization of periodontal ligament.

Is thereany difference between the
orthodontical movement of endodontically
treated and non-endodonticallytreatedteeth?

 Endodontically treated teeth can be moved as readily and for
the same distances as teeth with vital pulps. Both animal and
human studies showed that endodontically treated teeth can
be moved orthodontically as readily as vital teeth.
 But in case of replacement resorption (ankylosis) or injury
to apical periodontium, tooth movement may be prevented

 There has always been a concern with regard to
orthodontic movement of endodontically treated teeth
and assumption that these teeth might not respond as
readily to orthodontic force or that they might be more
susceptible to root resorption.
 However, since it is the response of the periodontal
ligament, not the pulp, that is fundamental to
orthodontic tooth movement, moving endodontically
treated teeth should be perfectly feasible

EFFECT OF PREVIOUS TRAUMATIC INJURIES ON
ORTHODONTICALLY-MEDIATED RESORPTION
AND
TOOTH MOVEMENT

 Orthodontic movement of traumatized teeth may be
associated with modified responses.
 It may become necessary orthodontically to move such
teeth, either because of a pre-existing malocclusion or
because tooth displacement caused by the trauma could
not be corrected manually at the time.

 In the case of teeth with compromised pulps that do not
manifest clinically, there is a higher chance that
orthodontic tooth movement may precipitate pulp
necrosis.
 It is important to monitor for signs of such changes
through altered tooth discomfort or discoloration.

 Teeth with repaired root fractures may be moved
orthodontically without risk of problems, even if the
fragments were previously dislocated.
 However, in those cases where the repair has not occurred
or is poor, root fragment separation may occur as a result.
 It has been suggested that teeth that had displayed root
separation at injury, albeit repositioned adequately
afterwards, should be observed for at least 2 years before
initiating orthodontic tooth movement.

 Teeth with ankylosed roots may be moved if the area
of ankylosis is relatively small, otherwise there is
likely to be no movement and, what is more, the teeth
providing anchorage could move in the opposite
direction

 Immature teeth may be more amenable to spontaneous re-
eruption.
 If a mature tooth, which has experienced severe intrusive
trauma and required pulp therapy for that reason, must be
repositioned orthodontically, resorption appears to be less
likely if a calcium hydroxide dressing is maintained until
the tooth movement is completed prior to definitive
rootcanal filling placement.

EFFECT OF ORTHOGNATHIC/ORTHODONTIC
TREATMENT ON TEETH AND THEIR PULPS

 The surgical procedures in general demand the raising of
large mucoperiosteal flaps, the sectioning of the alveolar
and/or basal bone distal or apical to the tooth apices
before repositioning of the entire tooth-containing block
of bone into a new and more favourable position.
 This is followed by fixation with wires or screwed plates.
During these procedures, it is possible that the blood
supply to teeth may be directly severed, sometimes
including the root apices.

 Otherwise, during longer procedures, blood supply may be
restricted to the teeth.
 The consequence is that the neurovascular bundle would be
affected, leading to loss of pulp sensitivity, rarely pulp
necrosis, and sometimes root resorption.
 Pulp revascularization may be evident but regrowth of nerve
supply is less likely.

 Research after segmental surgery has indicated that the
vascular supply of the teeth in the mobilized segment
remained intact, although unresponsive to electrical pulp
testing.

Are there any modifications in routine endodontic
procedures during the course of orthodontic therapy?

 The potential modifications to be accomplished in
routine endodontic procedures if at all attempted during
the progression of orthodontic therapy.
 These may be influenced by a number of diagnostic and
clinical factors.

 Full metallic bands may prevent an accurate response to
electrical or thermal pulp testing, in addition to shrouding
decay both radiographically and clinically.
 Patient symptoms may be due to the tooth movement or
to an inflamed or degenerating pulp, thus making a
differential diagnosis very difficult, especially if there has
been a history of trauma.
 The presence of pulpal calcifications may be due to both
an inflamed degenerating pulp following trauma or due
to orthodontic tooth movement
Diagnostic factors

 Tooth isolation is compromised by the presence of orthodontic
bands and wires. The placement of a rubber dam in these cases
needs additional measures to block potential avenues of leakage.
Often rubber dam clamps may also be modified by grinding or
bending to meet each anatomical challenge.
 Endodontic coronal access opening is not a problem in posterior
teeth because the approach is from occlusal direction. Lingually
or palatally placed brackets require creation of openings down
the long axis of the tooth through the incisal edge.
Clinical factors

 Working length determination is challenging in the
presence of apical resorption or root blunting as root end
is wide open from the resorptive destruction, even
electronic apex locators are unreliable and are of little
clinical value. Therefore many authors have suggested
locating the coronal point on the root above the resorbed
apex which exhibits sound radio density. This position is
used as the new radiographic apex and the working length
is established coronal to that point.

Obturation of teeth being orthodontically moved may result
in fills that are beyond the confines of the tooth.This is
especially true when using thermally softened gutta-percha
and vertical compaction techniques. In these cases,
techniques of creating an apical matrix or custom fitting of
a master cone may be appropriate

How orthodontic procedures facilitate to
optimize final endodontic output?

 The role of orthodontic tooth movement to optimizes the
prognosis of endodontic therapy by improving the access of
the tooth for a good restoration.
 Mainly two types of movement were appraised in the
literature in this perspective.
i. Orthodontic extrusion
ii. Orthodontic uprighting

Orthodontic extrusion
 The main intention of orthodontic extrusion is to provide
a sound tissue margin and to build a better periodontal
surrounding (biologic width) to construct a definitive
refined restoration, sometimes adjunctively periodontal
surgery may be required in this procedure.
 Common indications for orthodontic extrusion in this
situation include infra alveolar crest/sub gingival
fractures, pulpally involved deep root caries, resorptive
lateral root perforations, perforations made during post
and core preparations.

 The orthodontic extrusion of endodontically treated teeth did not
present any apparent problems. The alveolar housing moves
occlusally as the tooth is extruded followed by bone deposition
at the alveolar crest and throughout inter-radicular area.
 Adjunctively crown lengthening was done to optimize esthetic
results and biological width
 Orthodontic root extrusion or forced eruption is a well
documented clinical method for altering the relation between a
non-restorable tooth and its attachment apparatus, elevating
sound tooth material from within the alveolar socket.

 It has some advantages over surgical crown lengthening,
which is less conservative considering the sacrifice of
supporting bone and the negative change in the length of
the clinical crowns of both the tooth and its neighbours

Orthodontic uprighting
 In some instances orthodontic up-righting of posterior
teeth is attempted to augment embrasure space to aid in
definitive post endodontic restoration
 If at all second molars are drifted into a distally decayed
first molars can be up-righted orthodontically.
 Molars that are resected (hemisected or root-amputated)
can often benefit from enhanced embrasure spaces through
the use of orthodontic movement.

Orthodontic intervention of
apicocetomized tooth…….When?’

 it is possible to orthodontically move teeth that have been
subjected to endodontic periradicular surgery with root
resection.
 Baranowsky concluded that it might be sensible to allow
for a longer period of healing following apicoectomy prior
to orthodontic movement.

 Root resorption may be higher than the normal tooth due
to exposure of dentinal tubules
 Orthodontic treatment was discontinued for 4 months to
allow for healing then orthodontic treatment was
resumed.

conclusion
 Combined endodontic and orthodontic treatment planning can benefit
tooth prognosis by facilitating endodontic treatment and ensuring
optimal conditions for the final restoration.
 A Methodical and skill-full association is undeniably needed among the
endodontic – orthodontic interdisciplinary team approach to tackle the
compromised situations which are encountered in routine dental
practice for a successful outcome, functionally as well as esthetically.

References
 Text book of Endodontology- Franklin S Weine
 Endodontics – Kishor Gulabivala 4th ed
 Endodontic-orthodontic relationships: a review of
integrated treatment planning challenges R. S. Hamilton
& J. L. Gutmann International Endodontic Journal, 32,
343-360, 1999

 Endo-Orthodontics- Inside And Outside The Root–
Interactions- Venkata Ramana V Swapna M Annals And
Essences In dentistry 2010
 Orthodontic – Endodontic Considerations PART 1
Australian association of orthodontics

Endo ortho interface by DR. JAGADEESH KODITYALA

Endo ortho interface by DR. JAGADEESH KODITYALA

In this document