Open bite

Orthodontic treatment of dental open
Presented by:
Dr. Md. Ishtiaq Hasan
BDS, FCPS-II Trainee,
Dept. of Orthodontics, DDCH
Supervisor:
Prof. Dr. Md. Zakir Hossain
BDS, PhD(Japan)
Prof. & Head,
Dept. of Orthodontics,
DDCH.
bite: A case report

HISTORY AND DIAGNOSIS
• 35 years old female came to the department of
Orthodontics and Dentofacial Orthopedics, Dhaka
Dental College and Hospital with the chief compliant of
unpleasant aesthetic look due to spacing and
proclination of upper jaw.
• The patient was in the permanent dentition.
• She had no relevant dental, medical or family history
• No history of previous orthodontic treatment.

extra oral examination
Facial photo-Right view Facial photo-Frontal view Facial photo-Left view
A convex profile
Lips are incompetent at rest showing 75% of the upper central incisors
Lower midline shifted 2 mm right side
She had obtuse labiomental angle
She had increased lower facial height

Intraoral examination
Facial photo-Right view Facial photo-Frontal view Facial photo-Left view
She had an anterior open bite from right sided lateral incisor to left sided lateral incisor
Missing
Grossly carious
6 56
5
Canine relationship class-II on right side and class-I on left side
Overjet. 9 mm

Radiological Examination
Panoramic radiographs revealed that missing right sided
second premolar, first molar and left sided first molar.
Grossly carious right sided first premolar
Generalized bone loss.
There was no bony pathology

• Cephalometric evaluation showed—
Variables Values Bangladeshi norm Clinical norms Differences
SNA 79.1° 83° 80.0..89.0° -2
SNB 72.1° 81° 75.0..82.0° -9
ANB 7.0° 2° 2.0..4.0° +5
SND 69.0° 79° 76.0..77.0° -10
IIA 96.6° 117° 130.0..150.0° -21
SN-OcP 21.4° 13° 14.0° +8
SN-GoGn 46.4° 25° 30.0° +21
Max1-NA 33.5° 29° 22.0° +4
Max1-SN 112.7° 108.0° +4.7
Mand1-NB 42.9° 30° 25.0° +12
1u-NA 6mm 8mm 4mm +2
1l-NB 6mm 8mm 4mm +2
Holdaway Ratio 8mm 0..2mm +6
S-L 14mm 59mm 51mm -45
S-E 11mm 23mm 22mm -12
ANB angle is more than normal and IIA is less than normal. So, it is a case of skeletal class 2 div I.
MPA angle is more than normal (+21), so patient is hyperdivergent.

Aetiology
• Patient history revealed that she had thumb
sucking habit, suggesting that anterior open
bite etiology was related to thumb sucking.
• No respiratory problems were noted.

WHAT ARE THE CAUSES OF ANTERIOR
OPEN BITE AND WHY RELAPSE OCCUR
• Teeth & alveolar bones are
balanced by the forces of lips,
cheeks and tongue. If this balance
is altered, changes occur.
• Based on this idea of balance,
several etiological factors are
associated with AOB.

• The severity of AOB and sucking habits of fingers
and pacifiers have been well established.
• In such cases, AOB self-corrects consistently after
removal of habits, provided that no other
secondary dysfunctions have set in.
• The secondary dysfunctions may developed from
maxillary incisor protrusion generated by the
sucking habit, thereby breaking the lip seal
required for swallowing and causing the tongue
to be abnormally positioned, especially at rest.

• Hypertrophic lymphoid and tonsils are the most
common cause of nasal obstruction and
consequently may force the tongue to remain lower
to allow breathing to occur through the
oropharyngeal rather than nasopharyngeal space.

In 1964, Subtelus and Sakuda published an article on the diagnosis and
treatment of AOB. They try to find out an explanation for the existence of
persistency of open bite after removal of the causes. They found that in
case of persistent open bite, the following significant differences were
found---
• Greater eruption of upper molars
• Extrusion of upper incisors
• Increased mandibular plane and gonial angle
They named this facial pattern as ‘skeletal open bite’.
Its primary etiological factor is an unfavorable growth pattern with divergent
basal bones and therefore no contact between the incisors.
These etiological factors are associated with growth and not function and can
thus be defined as skeletal factors.

• Over the years, vertical facial pattern was ultimately considered as the
main risk factor for AOB and treatment stability. However, other studies
have reported that most hyperdivergent pts exhibit a normal or deepbite
while pt with normal facial patterns display a persistent open bite.
So, skeletal pattern cannot be the cause of AOB.

• Denison et al. assessed the stability of surgical
treatment in 66 adult pts followed up for at least
1 year after surgery. They found 42.9% of open
bite cases recurred and the relapse was due to
dentoalveolar changes and not for the skeletal
changes.
• Once hyperdivergency is successfully eliminated
with orthognathic surgery, it cannot be blamed as
an etiological factor for open bite relapse,
because these pts were adult, & exhibit no
growth.

• Therefore, it is believed that causes of relapse in
AOB are due to dentoalveolar origin, generated
by oral disorders, overlooked in the pretreatment
phase.
• Most investigations of AOB etiology agree on the
existence of secondary dysfunction, which remain
after the correction of etiology , such as stop
thumb sucking or removal of adenoids and
tonsils. This secondary dysfunction is poor tongue
posture at rest.

• Lower tongue posture at rest exert a long lasting
pressure on teeth, prevent eruption of incisors, thereby
causing and maintaining AOB.
• In addition, a low tongue posture may encourage the
eruption of posterior teeth and constrict the upper
arch since the tongue does not touch the palate.
• This etiological factor may not been studied enough
and is generally overlooked during AOB treatment.
• Failure to eliminate this factor may be the key reason
of AOB relapse.

Different types of the tongue at rest:
• The normal position of tongue is it rest on the
incisal papilla and its back lies along the
palate, keeping the anterior teeth in balance
while preserving the transverse dimension of
the upper arch.
• Tongue shows 4 types of abnormal resting
posture—high, horizontal,low and very low.

High posture:
• High posture of the tongue at rest is
associated with slightly protruded upper
incisors and AOB may exhibit vertical
overlap and positive horizontal overlap.
• Since the tongue rests on the palatal
surface of the incisors, beneath the
incisal papilla, upper incisors are
positioned above the occlusal plane.
• Leveling of the mandibular arch is
unaffected and display a single occlusal
plane.
• Posterior crossbites are not present as
the back of the tongue rests on the
palate while maintaining the transverse
dimension of the upper arch.

High posture of the tongue at rest, associated with a mild
AOB; may exhibit vertical overlap.
The maxillary incisors are protruded and lower arch leveling
is unchanged.
No posterior crossbite was observed.
The arrows represent the direction of the force exerted by the
tongue.

Horizontal position:
• In the horizontal posture
of the tongue at rest, the
tongue appears lower than
in the high position,
although with greater
protrusion, resting on the
palatal surface of the upper
incisors and on the incisal
edges of the lower incisors.

• The major effect in this case can
only be seen in the upper arch,
where protrusion of maxillary
incisors was more prominent, which
prevented their extrusion, thereby
causing AOB.
• Also due to the greater
protrusion of the incisors, a positive
and increased horizontal overlap was
noted.
• As the tongue positions itself
lower, its back turns away from the
palate allowing transverse changes
to occur in the maxillary arch, which
may cause posterior crossbites.

Horizontal posture of the tongue at rest, associated with a
moderate AOB; may exhibit vertical overlap.
The maxillary incisors are markedly protruded and above
the occlusal plane.
Lower arch leveling is unchanged.
Due to the distance between the back of the tongue and the
palate, posterior crossbites may emerge.

Lower position:
• As the tongue assumes a lower
position, pressure begins to be
exerted on mandibular teeth.
• In the low posture of the
tongue, it rests on the lingual
surface of the crowns of
mandibular incisors, thereby
protruding these teeth and
preventing their eruption,
which establishes a moderate
open bite.

• Due to protrusion in the lower
incisors, horizontal overlap may be
zero or negative.
• A gap can be seen between the
occlusal surfaces of posterior teeth
and the incisal surfaces of anterior
teeth in the lower arch only, with
lower incisors positioned below
the occlusal level.
• Posterior crossbites may be
present for the same reason
mentioned above.

Low posture of the tongue at rest, associated with a
moderate AOB. The mandibular incisors display a
pronounced protrusion.
Lower arch leveling is changed, with mandibular incisors
positioned below the occlusal level.
palate, posterior crossbites may emerge.
The arrows represent the direction of the force exerted by the
tongue.

Very low position:
• A very low tongue posture occurs when the
tongue rests below the crowns of the mandibular
incisors in the lingual region of the lower
alveolar ridge.
• The direction of tongue pressure produces
retroclination of mandibular incisors and
prevents their eruption, positioning them below
the occlusal level.
• The open bite is more severe and associated
with posterior crossbite due to the fact that the
tongue moves away from the palate.
• The tongue sprawls across the mouth floor,
expanding the lower arch in the transverse
direction.

Very low posture of the tongue at rest, associated with a
severe AOB.
The mandibular incisors appear uprighted or retroclined.
Lower arch leveling is changed, with mandibular incisors
well below the occlusal level.
palate, posterior crossbites are bound to emerge.
The arrows represent the direction of the force exerted by
the tongue.

High Upper procline
Lower no change (IMPA normal)
Vertical overlap present
No cross bite
Horizontal Upper more procline
Lower no change (IMPA normal)
Vertical overlap present
Post cross bite
Low Lower procline
No overlap
Lower incisors present below occlusal level
Post cross bite
Very low Lower retrocline
Lower incisors present below occlusal level
Post cross bite

Treatment choices based on tongue position at rest :
• High and horizontal tongue postures are positioned very close to normal
posture and require control in the horizontal direction only.
• It is suggested that blocking mechanisms such as cribs are sufficient to
produce this tongue retraction and adapt it to its correct posture at rest. This
type of treatment will be referred to as restraining treatment.
• However, in the low and very low tongue postures, the tongue is not only
protruded but it is positioned below its correct position and needs to be
retracted and elevated.
• This process is difficult to learn and automate, requiring educating devices
which force the direction of the tongue, such as spurs. This type of treatment
will be referred to as orienting treatment.

APPLYING CRITERIA FOR AOB DIAGNOSIS
AND TREATMENT: CASE REPORT

Case 1: high posture of tongue at rest
8 years old female pt
Mixed dentition stage
Angle class I malocclusion with AOB
Slightly increased overjet
Protruded maxillary incisors
Interincisal diastema in the upper
arch
The lower arch was normal
Face was symmetrical with slightly
convex profile

• Patient history did not reveal sucking habits, indicating
that AOB was caused by an abnormal posture of the
tongue at rest.
• AOB morphological characteristics indicated that the
patient had a high tongue posture as it did not change
the occlusal plane in the lower arch.
• However, the maxillary incisors were protruded and
positioned above the occlusal plane.
• Since the treatment goal was to restrain the tongue in
the horizontal direction, placing it further back,
restraining treatment was preferred and a Hawley
retainer was therefore used, combined with a crib.
• The retainer was used for a period of two years until
the patient was in the final stage of mixed dentition.

• She was monitored until the permanent dentition
phase. The AOB was closed, overjet and interincisal
diastemas reduced. No other treatment was performed
on this patient, who achieved a stable result as can be
seen from the records obtained 32 years after
treatment.
• It was only thanks to the removal of a poor tongue
posture that establishing a normal horizontal overlap
became possible and, more im- portantly, the AOB
etiological factor was eliminated, thus ensuring a
stable result for many years.

Hawley retainer with crib used to
treat patients for a two year period
until a normal overbite was attained.
Extraoral and intraoral photographs 32 years after treatment

Case 2:Horizontal Posture of tongue at rest
9 yrs old female pt
Mixed dentition
Angle class II div 1 malocclusion
8 mm overjet
Crossbite present
AOB
Midline shifted to the right less than 2 mm
Symmetric face
Convex profile
Skeletal pattern class II (SNA =88,
SNB=78, ANB= 10)
Mandibular plane angle normal (MPA 34)

• Patient history revealed that she had no
sucking habits, suggesting that AOB
etiology was related to abnormal tongue
posture.
• To determine what sort of tongue posture
the patient had it was observed that
lower arch leveling was normal while the
upper incisors were protruded and
positioned above the occlusal level. These
features suggest a horizontal posture of
the tongue associated with marked
overjet. Therefore, restraining treatment
would be indicated in this case.

• It was decided to use head gear (As incisors are
proclined), expansion screw (for crossbite) and palatal
crib (For AOB), which was worn for six months.
• After this period, an Angle Class I molar relationship
was attained with 3 mm overjet, the crossbite was
corrected as well as the AOB and there was improvement
in the skeletal relationship (SNA=83°, SNB=78° and
ANB=5°). The face remained symmetrical and the profile
slightly convex . The appliance was then worn only at
night for another six months for retention purposes.
• At age 12, the second phase of treatment was initiated
with the placement of a fixed metallic orthodontic
appliance.

headgear used in the first
treatment phase containing a
posterior maxillary splint with an
expansion screw, lingual crib and
Hawley clasp.
Extraoral photographs, cephalometric radiograph and intraoral
photographs at the end of the first treatment phase.

Extraoral and intraoral photographs at the end of the second treatment phase.
In this case, AOB correction occurred, thanks to a spontaneous extrusion
of the incisors after using a palatal crib and correcting the tongue posture.
The results were stable as can be seen in the follow-up photographs 10 years
after treatment.
Stability of AOB correction was accomplished because the etiological factor
was eliminated.

EXTRAORAL AND INTRAORAL PHOTOGRAPH 10 YEARS AFTER TREATMENT.

Case 3: High Posture of tongue at rest
7 years old female
Mixed dentition
Class I molar relationship
Tendency toward posterior crossbite
AOB
The face was balanced with no apparent asymmetries
Lip incompetence
Convex profile
Skeletal class I (SNA=78, SNB=77, ANB=1)

• No sucking habit was reported.
• The morphological features of this AOB
included slightly protruded maxillary
incisors with deficiently erupted and
protruded mandibular incisors
(IMPA=100°)
• These effects in the lower arch suggest
a low posture of the tongue at rest.
• Since this tongue had to be retracted and
elevated, it was decided to conduct
orienting treatment with spurs on the
lingual arch.

• The spurs were worn for a period of two
years and the patient monitored for
another two years until the permanent
dentition stage.
• By then the patient had developed a Class
I molar relationship, severe lack of space in
both arches, posterior crossbite on the
right side, and normal overbite.
• The mandibular incisors were uprighted
and extruded through the use of spurs
(IMPA=92°).
• The skeletal Class I relationship was
maintained (ANB=1°). Corrective
treatment was then initiated with
extraction of first premolars.
Panoramic radiograph of
patient with spurs in place,
reorienting the tongue
backwards and upwards.

Extraoral photographs, cephalometric radiograph and intraoral photographs after
use of spurs in permanent dentition. uprighting and
extrusion were
attained in the lower
incisors with the use
of spurs alone, and
the stable outcome
was monitored over 5
years.

Extra oral and intraoral photographs at the end of corrective treatment
after 7 years of spur use, showing stability of AOB correction.

Case 4: Very low Posture of tongue at rest
9 years old female patient
Severe AOB and severe lack of space in lower arch
She was a mouth breather and undergo speech therapy
Skeletal class III (ANB= -1)
Vertical growth pattern and MPA=49

• According to the morphological characteristics of the open
bite, the patient had a very low position of the tongue at
rest, clearly characterized by retroclination of mandibular
incisors (IMPA=70°) and posterior crossbite.
• To perform the correction it would be necessary to move
the tongue upward and backward with orienting treatment.
• The appliance of choice was a lower lingual arch with
spurs.
• Firstly, a single spur was placed in the midline region,
then other spurs were gradually inserted in the canine-to-canine
region.

• Use of lingual arch with spurs was suspended four years later. At
this time a significant improvement in vertical overlap was
observed as well as the presence of diastemas in the mandibular
incisor region due to the protrusion of these teeth. The profile
remained balanced and the face symmetrical . At this stage, it was
decided to place a fixed orthodontic appliance in the mandibular
arch in order to close spaces.
• The upper arch received no appliances and was monitored for a
period of one year to assess stability of AOB correction. Should
the AOB have relapsed it would have meant that the tongue
posture had not been corrected. An adequate vertical overlap was
achieved and the posterior crossbite corrected.

Spurs used on lingual arch,
start- ing with one spur at arch
center (A) and increasing
number and size of spurs (B) in
order to reorient tongue
posture backwards and
No expansion was performed in the uuppwpaerdr. arch
and crossbite was corrected by positioning the
tongue higher, thus changing the transverse
dimension of the arch.
The face remained symmetrical with a balanced
facial profile. At this stage, fixed appliances were
installed in the upper jaw to finish the case.

• Correction of this AOB was achieved mostly by a significant
extrusion of the mandibular incisors The backward and
upward change in tongue posture allowed eruption of the
incisors, thereby lengthening the alveolar process , as
reported by Meyer-Marcotty et al. The skeletal features of
this face would have one believe that the cause of the AOB
might be an unfavorable growth pattern. However, this
case suggests that AOB occurs — even in hyperdivergent
faces — when the eruptive process is hampered by a
mechanical obstruction (in this case the tongue), and thus,
skeletal pattern would not play an etiological role in AOB.

Extraoral and intraoral photographs after 4 years of spur use.
intraoral photographs after placement of appliance in the lower arch.

cephalometric x-rays comparing
initial and final treatment
phases. Radiographs shows
protrusion and marked
extrusion of incisors obtained
with the use of spurs only.
Removal of the causative agent of this AOB ensured
outcome stability 10 years after treatment. Treatment of
these cases requires patience and the long-term use of
spurs, which in this case lasted for 4 years. Due to AOB
severity, the amount of extrusion required for incisors to
attain vertical overlap is considerable . Moreover, the
process of automating tongue posture is slow, demanding
time for neuromuscular restructuring.

Extraoral and intraoral photographs 10 years after treatment.

Palatal or lingual crib:
• They are aimed to correct
AOB by preventing the tongue
from resting on the teeth.
• They must be long to prevent
the tongue from positioning
itself below them but it fails
to re-educate the tongue.
• In this case, the tongue
return to its original position
when it is removed, thus
leading to AOB relapse.

Palatal or lingual spur:
• It was described by Rogers in 1927 in the treatment of 3 open
bite cases.
• Spurs induce a change in the resting position of the tongue, thus
allowing tooth eruption and openbite closure.
• This change in tongue position alters sensory perception by the
brain, thereby producing a new motor response. This response
can be imprint permanently in the brain, which explains the
permanent change in tongue posture produced by spurs. This is
the main factors responsible for AOB treatment stability.
• Crib without spur simply restrain and does not retrain the
tongue, while spur discourage the tongue from resting against
them. A spur appliance is more effective in arresting finger
habits and correcting AOB than crib without spur.
• Huang et al. evaluated AOB treatment stability using spurs in 33
patients divided into 2 groups, one with and one without growth
and they found that AOB correction occurred in both cases.

Clinical recommendations:
• Spur appliance should be non-removable.
• It should remain in the mouth at least 6 months after the
AOB has ceased.
• Spur is constructed with .045 inch ss wire (similar to a
mandibular lingual arch) to which eight short, sharpened
0.026 inch spurs, 3 mm in length, are soldered from canine
to canine.
• The spurs are positioned 3 mm away from the cingulum of
the incisors and are directed at an angle (downward &
backward) to encourage correct tongue posture, with the
tip of the tongue behind the upper central incisor papilla.

• The AOB usually takes 6-8 months to close after appliance cementation but
may take a longer time for some patient.
• At the end of active orthodontic treatment without bonded spur appliance,
a removable appliance with spurs will not be successful. In that cases, fixed
spurs should be given because patient cannot wear removable spur
appliance full time and part time wearing of a removable spur appliance is
not effective in closing open bites. It takes 2-3 weeks for patients to adopt to
speaking, swallowing and eating with cemented spurs. Therefore , it is
reasonable to expect patients who have never used fixed spurs to wear a
removable spur appliance full time until the bite closes.
• To avoid making patient afraid, Dr. Roberto Justus advised to refer the spur
appliance as ‘the reminding appliance’ in front of the patient.

• A mandibular spur appliance is as effective as maxillary one, except
that it is visible and patient might find it objectionable since they
should be continuously asked about the appliance.
• Haryett et al. concluded that spur appliance do not cause
psychological problems and there are no reports of pain or injury to
the tongue and no marks or bruises can be seen on the tongue when
using spurs.
• When cementing the spur appliance, the family should be informed
that there will be some initial difficulty speaking, eating, and
swallowing. All of these problems will be resolved in 2 to 3 weeks.
During this period, patients are asked to cover their spurs with cotton.
The tongue is thus protected and can gradually adapt to the spurs.
• The patients should also be advised to pay particular attention to
hygiene on the lingual aspect of the maxillary incisors because the
spur appliance makes brushing this area more difficult.

When an orthodontist is faced with an anterior open bite
relapse, Dr. Roberto Justus recommends the following-----
• Explain to the family the possibility that the relapse is due
to an anterior tongue rest posture problem.
• Determine whether orthognathic surgery is indicated or
not.
• If surgery is not advisable, recommend a cemented
reminding appliance with spurs.
• Encourage the family by giving them a copy of an article
that shows cases successfully treated with the spur
appliance.

• A mandibular canine to canine fixed retainer or a
removable lower retainer is given to avoid incisor
crowding.
• Bond a upper canine to canine retainer to ensure that
the maxillary incisor alignment is maintained.
• Allow the spur appliance to remain in the mouth for at
least 1 year, even though the bite may have closed in 6
to 8 months.
• Do not expect the bite to close immediately.

Contra-indications of spur appliance---
• Diminished muscular control.
• Abnormally large tongue.
• Maxillary lateral incisors have not yet erupted (indicating that closing a
transitional anterior open bite).
• Stressful periods in patient/parents lives (illness, divorce, school exams, etc).
• Immaturity (lack of understanding treatment goals).
• Increased nasal resistance, allergic rhinitis, or enlarged tonsils and/or
adenoids (particularly during an acute episode).
• Ongoing speech therapy. Speech therapy should preferably be instituted after
the bite has closed because the speech therapist can work more effectively
with a child who does not have an anterior open bite.
• Bad oral hygiene.
• Severe skeletal dysplasia (need orthognathic surgery).

Orthodondic or surgical treatment of
AOB?
• Surgical treatment is indicated for extremely
severe cases with MPA above 50
• In orthognathic surgery cases, spur appliance
should be considered post-surgically and only
if an open bite begins to relapse.

TREATMENT OBJECTIVES
Considering the above findings the objectives of
orthodontic treatment of this patient were to –
• Correction of anterior open bite.
• Correction of median diastema.
• Reduce lip procumbancy and lip incompetency.
• Retrocline upper and lower incisors.
• Establish normal overjet and overbite.
• Establish normal interincisal angle.
• Correction of midline.
• Improve gingival condition.
• Improve profile
• Establish and maintain occlusal harmony and
interdigitation for improved aesthetics and proper
function.

TREATMENT PLAN AND PROGRESS
• Due to badly destruction of lower right first
premolar, it was decided to extract the
tooth.
• The treatment plan was to extract both
upper first bicuspids to retrocline upper
incisors and reduce lip incompetency and
distal movement of lower right canine and
left premolars.
• But patient refused to extract teeth as
because she already lost so many teeth.
• So we try to retract upper incisors and
reduce lip incompetency as much as possible
by utilizing the space available between the
upper incisors.

• Edgewise bracket was bonded 1 mm gingival to the centre
of the crown of upper and lower incisors to extrude them
and to reduce anterior open bite.
• Initial leveling and alignment was done with the use of
0.014 ss multiloop arch wires.
• Upper spacing were closed by power chains with 0.016 ss
round wire.
• Upper arch contraction was done by 0.016x 0.022 inch
rectangular ss arch wires with tear drop contraction loops .
• At the end of treatment, elastics was used for better
interdigitation.

Fig: Initial leveling and alignment by
0.014 ss round wire with multi-loop.
Fig: closing space between central incisors
by 0.016 ss round wire with power chain.

Fig: Arch contraction – right side
Fig: Arch contraction by .016*.022 ss
rectangular wire with tear drop loop.

DISCUSSION AND RESULTS:
• Total treatment time was 24 months.
• The result was slightly compromised in that
there on right side, canine relationship was not
class I and lip procumbancy was not fully
corrected as because the patient refused to
extract teeth.
• However, the patient was happy with his
appearance and reduced lip incompetency.

Cephalometric measurement before and after —
Variables Before treatment Clinical norms After treatment
SNA 79.1° 80.0..89.0° 78.2°
SNB 72.1° 75.0..82.0° 71.5°
ANB 7.0° 2.0..4.0° 6.7°
SND 69.0° 76.0..77.0° 68.8°
IIA 96.6° 130.0..150.0° 121.2°
SN-OcP 21.4° 14.0° 23.7°
SN-GoGn 46.4° 30.0° 47.8°
Max1-NA 33.5° 22.0° 16.3°
Max1-SN 112.7° 108.0° 94.5°
Mand1-NB 42.9° 25.0° 35.9°
1u-NA 6mm 4mm 4mm
1l-NB 6mm 4mm 7mm
Holdaway Ratio 8mm 0..2mm 0mm
S-L 14mm 51mm 7mm
S-E 11mm 22mm 14mm

——— Initial
——— Post Treatment
Cephalometric superimposition
Cephalometric radiography
superimposition comparing
before and after showed that
the open bite problem was
corrected by---
•The upper incisors tipped
backward and retracted
•The lower incisors extruded
due to positioning of
brackets 1 mm gingival to
the centre of the crown.
•Upper and lower molars
were not extruded; Extrusion
of molars are not advisable in
open bite cases as because of
relapse tendency.

SEGMENTAL SUPERIMPOSITION
Dental Maxilla Soft Tissue Profile
Upper Lip Drape

At the end of treatment---
• Facial photographs
show an improved
profile.
• Lip procumbency was
reduced.

• Ideal overjet and
overbite were achieved.

• Proper alignment and
nice gingival contour
were attained.

Tooth loss due to periodontal disease--
• When a tooth lost due to periodontal disease, that space is
very difficult to close.
• As a general rule, it is better to move teeth away from such
an area, in preparation for a prosthetic replacement,
because of the risk that normal bone formation will not
occur as the tooth moves into the defect.
• In older pt who has lost a tooth due to periodontal disease,
it is not a good judgment to attempt to close the space.
--------PROFFIT

• It is important to explore and understand various aspects of
orthodontic treatment where adults need special
considerations in contrast to adolescents.
• Adult orthodontics is basically same as adolescent
orthodontics for tissue changes associated with tooth
movement, stages of treatment and goal of treatment.
• But there are certain differences in several aspects namely
psychosocial, biological and mechanical aspects where
adults need special consideration for behavioral and clinical
management

Psychosocial factors
• Adult patients have high treatment expectations.
• They are more serious about the detail of the treatment as treatment time,
complexity of treatment, number of visits, likelihood of correction etc.
• They have been shown to have more discomfort from appliances.
• They are more co-operative in following the instructions from orthodontists
such as elastic wear, hygiene maintenance, keeping their appointments etc.
but they don’t commit to long-term treatment .
• In other words, adults demand best treatment results in a short time.
• Therefore, it is quite important to apprise these patients about the limitations
& complexity of the treatment, increased treatment time & high relapse
potential.
• Adult patients may have hesitation in accepting visibility of orthodontic
appliances. They may demand esthetic appliance e.g. esthetic brackets,
lingual appliance, invisalign etc irrespective of their limitations .

Periodontal susceptibility
• Adolescents more resistant to bone loss as a
result of periodontal disease but highly
susceptible to gingival inflammation.
• Adults Higher degree of susceptibility to bone
loss as a result of periodontal disease.

The bone level
• The minimum amount of bone support necessary for teeth
to withstand orthodontic forces in a plaque-controlled
environment has yet not been established. Reduced bone
support is not a contraindication to orthodontic therapy.
• The ideal alveolar bone for closing first molar space is 6 mm
in mesio-distal direction and 7 mm in bucco-lingual
direction. If the pt does not fit these characteristics, one
can start guided bone regeneration technique, which is
widely used for orthodontic movement in areas with bone
defects.

CONSIDERATIONS REGARDING
EXTRACTION
• Extraction choice may be affected by
periorestorative status of dentition or already
extracted tooth complicating the treatment plan.
• In adults, closing an old extraction site is difficult.
When there is a dense cortical layer of bone
formed within the alveolar process of a
previously (long ago) extrated tooth, it become
very difficult to close the space.

• Tooth movement is slowed to a minimal when the root encounters
cortical bone along the resorbed side of alveolar ridge.
• Tooth movement is also greatly slowed & root resorption more
likely when a tooth is faced against a cortical plate.
• Maintenance of closed spaces is also very difficult (difficult to close
and keep it closed).
• It may need uprighting to open the space mesially to receive
prosthesis rather than attempting space closure.
• Existing occlusion is maintained when occlusal difficulties are not
present. Lower incisor extraction & proximal stripping are preferred
over bicuspid extraction to relieve crowding.

CONSIDERATIONS REGARDING APPLIANCE PLACEMENT
• While bonding, special considerations may be
required due to presence of restorations such
as porcelain and metallic surfaces.

BIOMECHANICAL CONSIDERATIONS
Adult bone is less reactive to mechanical forces .
Loss of attachment leads to apical shift of centre
of resistance, thereby increasing distance from
centre of resistance to point of force application in
turn leading to increased tipping moment
produced by the given force.
Therefore greater countervailing moment is
required to balance this greater tipping moment
to translate periodontally compromised tooth .
When bone has been lost, same amount of force
produces greater pressure in PDL of a
compromised tooth than a normally supported
one.

Considerations Regarding Tooth movements
• To correct deep bite in young patients, posterior extrusion is
allowed because of compensation made by vertical growth. But
overbite correction in adults should be carried out by intrusion of
anterior teeth, not by extrusion of posterior teeth.
• Palatal expansion is carefully done to avoid buccal tipping due to
extrusion associated with it.
• Most mechanotherapy has extrusive component. Retraction force
has a larger extrusive force component if the bone loss is most
pronounced. Hence, light continuous intrusive force should be
maintained during retraction.
• In adult patients, segmented arch mechanics is preferred because
light force is required for adults.

CONSIDERATIONS REGARDING VULNERABILITY TO
ROOT RESORPTION
• Adult patients must be informed about the
risk of root resorption and thoroughly
evaluated for the susceptibility to root
resorption . All measures should be taken to
manage root resorption.

CONSIDERATIONS REGARDING
VULNERABILITY TO TMD
• There is a higher risk of developing TMD in
adults than adolescents, which may not be
related to orthodontic treatment.
• Hence, adult patients need a thorough check
up for the signs of TMD before initiation of
orthodontic treatment.

CONSIDERATIONS REGARDING TREATMENT TIME
• Tissue remodeling associated with tooth movement is slow leading
to slow rate of tooth movement making the treatment time longer.
• Activation in adults usually in 50’s and onwards is required to be
done after longer period i.e. 3-6 weeks as against 2-4 weeks
required in adolescents.
• Initiation of tooth movement takes longer time as compared to
adolescents. The delayed response to mechanical stimulus, is
suggested to be caused by insufficient source of preosteoblasts as a
result of reduced vascularization with increasing age.
• After delayed initial tissue reaction, rate of tooth movement in
adults is not that much different as compared to that in
adolescents.

2 years after treatment (Follow up)

Immediately after treatment 2 years after treatment

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