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ADVANCED DENTAL NURSING
www.nature.com/vital vital 31
COMMUNICATION
ADVANCED DENTAL
NURSING SERIES
CLINICAL GOVERNANCE
ORAL HEALTH EDUCATION
SPECIAL CARE DENTISTRY
DENTAL ANXIETY
IMPLANT NURSING
ORTHODONTIC TREATMENT
Introduction
Orthodontics is the branch of dentistry
concerned with facial growth, development
of the dentition and occlusion together
with the prevention and correction of
occlusal anomalies. e main indications for
orthodontic treatment are to improve oral
function, aesthetics and general dental health.
e main aims of orthodontic treatment are,
therefore, to eliminate functional problems
that may predispose a patient to TMD;
encourage the eruption and alignment of
displaced or impacted teeth; remove any
trauma from occlusion and/or displaced
teeth and/or improve facial and dental
aesthetics by aligning and levelling the teeth,
correcting the overjet and overbite to establish
a mutually protective occlusion, within a
stable so tissue environment. e benets
of orthodontic treatment can be considered
in terms of reducing the negative impact that
a malocclusion has on the dental health and
psycho-social well-being of an individual.
However, orthodontic treatment does carry
risks which include decalcication, root
resorption, gingival and periodontal problems
and the failure to achieve the aims of treatment.
It is important, therefore, that treatment should
not be started unless there is a reasonable
chance that the patient will benet from it.
is article aims to outline the process of
orthodontic assessment, treatment planning
and the treatment modalities available to
correct patients’ problems.
Assessment of a patient for
orthodontic treatment
Before any orthodontic treatment plan is drawn
up it is very important to reach a diagnosis
and establish a problem list. In order to do
this the orthodontist must take a history from
the patient and parent (if appropriate) and
undertake a thorough examination of the hard
and so tissues of the face and mouth. Special
investigations such as radiographs, study
models and photographs are also required
before arriving at the nal treatment plan.
History
In the history, it is important to nd out the
patient’s main concerns, the reasons why
they are seeking treatment and their attitude
towards treatment together with an assessment
of the potential level of co-operation with any
proposed treatment. At this point, children
should be encouraged to voice their opinions
about their teeth and how they feel about the
prospect of orthodontic treatment.
Examination
e examination of the patient will include
extra- and intra-oral assessments of the skeletal
pattern; so tissues; temporomandibular
joints (TMJs) and dental relationships. e
skeletal pattern is assessed by examining
the patient - sitting in an upright position,
looking straight ahead - in the anteroposterior,
vertical and transverse dimensions. e lips
need to be examined at rest and in function
It is important that all
members of the dental
team understand the
reasons for undertaking
orthodontic treatment
and the principal
treatment options that
are available to the
patient, says Jayne
Harrison, Consultant
Orthodontist at
Liverpool University
Dental Hospital.
Orthodontic treatment
EXCLUSIVE TO VITAL!
This article is adapted from a
chapter of the second edition
of Advanced dental nursing
edited by Robert Ireland and
published by Wiley Blackwell in
May 2010 (£29.99).
ADVANCED DENTAL NURSING
32 vital www.nature.com/vital
to determine their competency, position and
length. e TMJs need to be checked for signs
of temporomandibular disease including joint
noises, extent of opening and deviation when
opening/closing. e intra-oral examination of
a patient for orthodontic reasons is similar to
that performed for routine dental patients but
puts more emphasis on the inter- and intra-arch
relationships. e incisor, canine and molar
relationships are assessed together with the
overjet, overbite, centrelines – in relationship
to each other and the facial centre line –
transverse relationships, including crossbites,
scissors bites and any associated displacement
on closing. e general dental health must also
be considered so any active or restored caries
should be noted together with an assessment of
the patient’s level of oral hygiene.
Special investigations
Impressions of the upper and lower jaws are
taken and reproduced as study models. e
study models are then used to record the
treatment from start to nish and are used to
observe the changes that take place throughout
the orthodontic procedure. Radiographs are a
valuable addition to the information gathered
during the examination of a patient. ey
are used to assess facial and dento-skeletal
relationships and to identify any missing,
unerupted or impacted teeth. e most
commonly used radiographs in orthodontics
are the orthopantomograph (OPG, OPT),
lateral cephalogram and intra-oral views of the
teeth in the upper labial segment. Photographs
are also taken before treatment commences,
during treatment and post-treatment. ey
record the severity of malocclusion, changes
occurring during treatment as well as a
useful record of any pre-existing pathology,
decalcication or trauma to the teeth.
Problem list
Having gathered information from the patient,
the clinical examination and appropriate special
investigations, a list of the patient’s problems
can be put together. is should be an overall
problem list of all the patient’s dental problems,
not just the orthodontic ones. is means that
any pathology eg caries, or gingivitis, needs
to be brought under control and treated as a
priority before orthodontic treatment is started.
When thinking about the orthodontic
problems, again the treatment of any pathology
eg impacted teeth, ankylosed teeth, and
root resorption, takes precedence. Skeletal
discrepancies, in all three planes of space,
also need to be recognised, quantied and
prioritised. Dental problems including any
excessive protrusion or retrusion together
with problems involving dental development
eg abnormal sequence of development,
missing teeth and supernumerary teeth, are
then considered. Finally, problems involving
crowding and malalignment of teeth
are considered.
The timing of orthodontic treatment
In most cases the timing of orthodontic
treatment is related to the stage of
dental development.
Deciduous dentition Treatment of
crowding or spacing is not indicated in the
primary dentition, but crossbites that cause a
displacement on closing, whether anterior
or posterior, can be treated successfully at
this stage.
Mixed dentition Treatment in the mixed
dentition can involve the extraction of
deciduous teeth, the correction of an anterior or
posterior crossbite and/or growth modication.
Early permanent dentition e majority of
xed orthodontic treatment is carried out at the
early permanent dentition stage.
Adult dentition Most types of orthodontic
treatment, with the exception of growth
modication, can be undertaken in adulthood.
Orthognathic surgery is best delayed until this
stage to ensure that growth has stopped.
Types of orthodontic treatment
In the absence of a skeletal discrepancy,
malaligned teeth can be aligned, once sucient
space has been created, using xed orthodontic
appliances. Space can be created in a variety
of ways including extraction of appropriate
teeth, arch expansion and/or interproximal
enamel reduction.
If the patient has a skeletal discrepancy,
there are three main approaches to
orthodontic treatment:
1. Growth modication - growth is used
to correct the skeletal discrepancy. To
correct a skeletal discrepancy using growth
modication, the patient needs to be growing
so this type of treatment is best carried out in
the late mixed or early permanent dentition.
Growth modication treatment can involve
the use of a functional appliance and/
or headgear
2. Camouage treatment. If the patient is near
or at the end of growth, mild or moderate
skeletal discrepancies may be treated with
camouage treatment that involves the
use of xed orthodontic appliances, oen
in combination with extractions, to
move the teeth so as to disguise the
skeletal discrepancy
3. A combination of orthodontic treatment
and orthognathic surgery to correct the
malocclusion and underlying skeletal
discrepancy. If the skeletal discrepancy is
severe and the patient is at the end of growth,
then the malocclusion and underlying
skeletal discrepancy can be treated using
a combination of orthodontics and
orthognathic surgery.
Functional appliances
Functional appliances are a group of
‘ Orthodontics is
concerned with
facial growth,
development
of the dentition
and occlusion
together with
the prevention
and correction
of occlusal
anomalies.’
Quad helix appliance Transpalatal arch
ADVANCED DENTAL NURSING
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orthodontic appliances that aim to modify the
growth of the jaws by using the forces generated
within the masticatory and facial muscles.
Most functional appliances are removable
but some, eg the Herbst appliance, are xed to
the teeth for the duration of active treatment.
e majority of functional appliances have been
designed to correct Class II malocclusions eg
the Twin Block, Andresen, Harvold, bionator
and Frankel appliances. However, some have
been modied to correct Class III malocclusion,
eg the Frankel FR3 appliance. Functional
appliances to correct a Class II discrepancy are
designed to hold the mandible forwards oen
to an edge-to-edge position. For a Class III
discrepancy only minimal posterior positioning
of the mandible is possible so the mandible is
held open and rotated backwards.
Functional appliances are usually worn
full time and work in a similar way. For Class
II cases, the appliances hold the mandible
forwards so that the teeth are not in occlusion,
the condyles of the mandible are displaced from
the glenoid fossa and the muscles of mastication
are stretched. For Class III cases, the appliances
hold the mandible in a posterior position and
open in an attempt to redirect mandibular
growth in a downward and backwards
direction. In each case the repositioning of the
mandible generates forces that are directed
primarily to the teeth but can also have an eect
on the growth of the maxilla and/or mandible.
ere are several theories on how functional
appliances bring about the changes they do.
ese include the following.
Dentoalveolar changes Evidence on the
eects of functional appliances suggests that
most of the changes (70-80%) that they bring
about are due to changes in the dentoalveolar
complex. In Class II cases the maxillary incisors
retrocline and the eruption of teeth in the
maxillary buccal segments is directed distally
during treatment. In the mandibular arch the
lower incisors tend to procline and the teeth
in the buccal segments erupt in a more mesial
direction. e reverse occurs in Class III cases.
Skeletal changes Evidence on the eects of
functional appliances suggests that only 20-30%
of the changes that they bring about are due
to alterations in the growth of the maxilla or
mandible. In Class II cases there is minimal
restriction of maxillary growth and about 1-3
mm increase in mandibular growth. In Class III
cases studies show that there is 1-2 mm increase
in maxillary growth and 1-2 mm restriction
of mandibular growth. Functional appliances
also have the eect of redirecting mandibular
growth downwards and backwards. is may
not be benecial in Class II cases but appears to
improve a Class III relationship.
Changes in the glenoid fossa Animal studies
have shown that when the condyle of the
mandible is displaced from the glenoid fossa, it
remodels causing the temporomandibular joint
and mandible to move forwards. However, the
evidence that this also happens in humans is
weak and if it does occur, the changes it causes
are minimal.
Fixed orthodontic appliances
Fixed appliances can move the teeth in all
directions. These appliances are xed to the
teeth and forces are applied by archwires or
auxiliaries through these attachments. Fixed
appliances can:
• Tip – change the mesio-distal angle of teeth
• Torque – change the bucco-lingual
inclination of teeth
• Rotate teeth
• Bodily move teeth.
A xed appliance has attachments (brackets,
tubes, bands), which are attached to the teeth
by composite resins (brackets, tubes) or cement
(bands).
Phases of treatment
e progress of most orthodontic treatment,
using xed appliances, falls into quite well-
dened phases. ere are subtle variations on
this basic format and patients may be treated
with other types of appliances before or as part
of their xed appliance therapy.
Bonding and banding is is normally
completed over two or three visits. A typical
pattern is to place the brackets on the anterior
teeth and separators between the molars at the
rst visit. At the second visit the bands can then
be selected and tted and the archwires placed.
Levelling and aligning Levelling and aligning
involves levelling the curve of Spee (the curve in
the occlusal plane in the antero-posterior plane)
and aligning the teeth. Alignment is usually
carried out over several visits using exible
nickel titanium (eg 0.014” and then 0.018” x
0.025”) archwires to align the teeth.
Overbite reduction Overbite reduction is
a key stage in most courses of orthodontic
treatment because it is impossible to obtain a
Class I incisor relationship unless the overbite
is fully reduced. Eective overbite reduction
needs sti archwires and only starts to occur
when stainless steel archwires, of at least 0.016”
diameter, are in place with 0.019” x 0.025”
stainless steel archwires being the most eective
and bring about most of the overbite reduction.
Overbite reduction can also be initiated by an
upper removable appliance (URA), with a at
anterior bite plane, used in conjunction with a
lower xed appliance at the start of treatment.
Overjet reduction Overjet reduction is
usually achieved by retracting the upper labial
segment once the overbite has been reduced.
is can be assisted by forward mandibular
growth, maxillary restraint, distalisation of
maxillary molars and/or advancement of the
lower labial segment. Overjet reduction can be
brought about using a combination of space-
closing mechanics and is usually carried out on
a 0.019” x 0.025” stainless steel archwire
Pre-adjusted fixed appliancesTwin Block appliance
ADVANCED DENTAL NURSING
34 vital www.nature.com/vital
– the working archwire. A variety of auxiliaries
can be used alone or in combination to reduce
the overjet. ese include active tie-backs,
elastomeric chain or springs between the
maxillary molars and canine hooks, Class II
elastics and/or headgear.
Space closure Once the overjet has been
reduced, any residual space needs to be closed.
Several auxiliary attachments may be used
to bring this about, eg active tie-backs, nickel
titanium closed coil springs, elastomeric chain
and Class II or III elastics.
Finishing and detailing Once the desired
incisor, canine and molar relationships have
been achieved it is usually necessary to
nish and detail the occlusion to achieve the
best possible occlusion. At this stage careful
attention is paid to the position of the brackets
and bands because if they are incorrectly
positioned, the teeth will not be in their ideal
position. It is therefore quite common for
brackets or bands to be repositioned at this
stage. Inter-maxillary elastics, placed in a
variety of patterns, can be used to achieve a well
interdigitated occlusion at the end of treatment.
Debond Once the best possible occlusion
has been achieved arrangements are made to
remove the xed appliance, clean the teeth and
provide the patient with retainers.
Retention Following active orthodontic
treatment, it is important that the teeth are
held in their new position so that relapse does
not occur. is stage of treatment is called
retention. Retainers maintain the teeth in
the position achieved by active orthodontic
treatment whilst the gingival tissues and
bone around the teeth heal. Retainers can be
removable or xed to the teeth.
Orthognathic surgery
If a patient has a signicant skeletal discrepancy
then orthodontic treatment alone may not
be sucient to correct all aspects of the
malocclusion and facial disproportion. In
such cases it may be necessary to consider
orthodontic treatment combined with
orthognathic surgery. Orthognathic surgery
is that branch of surgery concerned with
the correction of dentofacial deformity and
particularly with disproportions of the tooth-
bearing segments of the jaws, and associated
facial skeleton.
Stages of treatment
ere are several stages of treatment for
patients undergoing a combined orthodontic/
orthognathic treatment plan. ese include:
History and examination When initially
seeing the patient it is important to establish
their motivations for treatment. ese may
include aesthetic concerns regarding their teeth
Assessment of a patient for orthodontic treatment
History
Patient’s main concerns
Reasons why they are seeking treatment
Attitude towards treatment together
Potential level of cooperation
Medical history
Social history
Examination
Extra-oral examination
Skeletal pattern
Antero-posterior
Vertical
Transverse
Soft tissues – lips
Competency
Smile line
Fullness
Temporomandibular joints (TMJs)
Sounds
Opening
Deviation
Intra-oral examination
Inter-arch relationships
Incisor, canine and molar
relationships
Overjet
Overbite
Centrelines
Cross/scissors bite ±
displacement on closing
Intra-arch relationships
Alignment
General dental health
Active or restored caries
Patient’s level of oral hygiene
Special investigations
Extra-oral examination
Radiographs
Orthopantomograph (OPG, OPT)
Lateral cephalogram
Intra-oral views of upper labial segment
Photographs
Intra-oral
Extra-oral
ADVANCED DENTAL NURSING
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and/or face or functional problems that may
give rise to diculties eating certain foods,
signs and/or symptoms of temporomandibular
joint dysfunction or a speech impediment.
Preliminary planning At this stage an
assessment of where the skeletal discrepancy
lies, in all three planes of space, is made to
establish what surgery will be required to
correct it. e surgery may involve the maxilla,
mandible or both jaws and occasionally other
procedures eg genioplasty. From an orthodontic
point of view, the expected tooth movements
needed to be undertaken pre-surgically and
extractions necessary are planned.
Pre-surgical orthodontics e aims of pre-
surgical orthodontics are to maximise the
benet of the surgery. In order to do this it is
usually necessary to:
• Relieve crowding. Just like in conventional
orthodontics, any crowded teeth are aligned
during the pre-surgical phase
• Correct centre-lines. e centre-lines need to
be corrected relative to the facial centre-line
and those of the individual jaws
• Decompensate. During the development of
a malocclusion the upper and lower incisors
tend to compensate for the underlying
skeletal discrepancy. e implication of
compensation on orthognathic surgery is that
the amount the jaws can be moved is limited
so, in order to maximise the movement of the
jaws the surgeon can undertake, the incisors
usually have to be moved so that they are at
the correct angle to their respective jaw
• Co-ordinate the arches. e width of the
arches oen needs to be adjusted so that they
t in a normal bucco-lingual relationship
when the jaws are in their new position
aer surgery
• Level or maintain the curve of Spee. is
depends on the presenting malocclusion.
Final planning At this stage full records
of the patient are taken so that a check can
be made that the planned orthodontic tooth
movements have been achieved. Special
attention is paid to the centre-lines, incisor
angulation and t of the arches. At this point,
the amount of skeletal movement required
to correct the malocclusion, in all three
planes of space, can be determined. Working
study models are made and mounted on
an articulator so that the anticipated jaw
movements can be simulated and the planned
occlusion achieved. From these models acrylic
wafers are made that the surgeon uses to
guide the teeth and jaws into position during
the surgery.
Surgery In theory it is possible to move the
jaws in three planes of space, however, some
movements are harder to do or not as stable as
others. e most frequently carried out surgical
movements in the maxilla are advancement,
expansion, impaction and down fracture with
bone graing. In the mandible advancement
and set back are the most common procedures.
Most procedures these days are carried
out from within the mouth so that it is rare
for patients to be le with any external scars
following surgery. e jaws are usually held
in their new position by small titanium plates
or screws. e main complications of these
specic procedures are nerve damage, swelling
and bruising. ese usually resolve over
the following weeks or months but a small
proportion of patients will be le with a small
area of numbness or altered sensation overlying
the exit of the nerve from the respective jaw.
Post-surgical orthodontics Immediately aer
surgery it is common for patients to have a
limited number of teeth in occlusion. e aims
of post-surgical orthodontics are therefore to
maintain the surgical correction achieved; level
the curve of Spee if necessary; close down the
lateral open bites; nish and detail the occlusion
to achieve maximal intercuspation.
Debond and retention – As for xed
appliance treatment.
Summary
Patients present for orthodontic treatment with
a very wide range of problems and deciding
which treatment to provide them with depends
on the diagnosis, ie what’s wrong. Once the
orthodontist has reached a diagnosis and
formed a problem list, then the appropriate
treatment to correct the patient’s problems can
be selected from the range that is available to
the specialist orthodontist.
Phases of fixed orthodontic treatment
Bonding and banding
Levelling and aligning
Overbite reduction
Overjet reduction
Space closure
Finishing and detailing
Debond
Retention
Top: Pre-treatment, Middle: Mid-treatment,
Bottom: Post-treatment
‘ The most
frequently
carried out
surgical
movements in
the maxilla are
advancement,
expansion,
impaction and
down fracture
with bone
grafting.’
