Lingual 2

DIAGNOSIS AND TREATMENT PLANNING
• PATIENT SELECTION
• TIME & COST FACTORS
• TREATMENT PLANNING
 Periodontal considerations
 Restorative considerations
 Lingual crown height
 Additional treatment plan considerations
 TMJ considerations
• GUIDELINES FOR CASE SELECTION
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PATIENT SELECTION
Important factors
Inadequate personality screening
Failure of pt. to understand the
Possible side effects & necessity
Of adaptation
Personality of the patient
Reasons for seeking treatment
Failure of lingual treatment

TIME & COST FACTORS
• Examination ,diagnosis, consultation & treatment
planning time – increases by 30-45 min
• Lab procedures for indirect appliance setup
• Increase in chair side time
• May be necessary to finish some pt’s with labial
appliance
• Fully articulated positioner appliance may be
required for detailing lingual case

TREATMENT PLANNING
Periodontal considerations :
Not a suitable candidate for
lingual orthodontic treatment
Short clinical lingual crowns
can be lengthened by
Pt’s with a H/O periodontal
problems
Pt’s in whom oral hygiene
motivation is questionable
Reduction of inflammation
Surgical procedures

Restorative Considerations
In cases where there is a loss of several
teeth, extreme tipping & multiple or
complex bridgework, the lingual appliance
may be contraindicated.

Lingual Crown Height
• Lingual crown height- 30% shorter than labial crown height
• Most critical lingual crown heights- maxillary incisors &
mandibular bicuspids
• 7mm of lingual crown height is necessary on maxillary incisors
• Short clinical crowns- optimum bracket positioning cannot be
achieved to minimize 2nd
order bends

Attention should be given in following instances
• Extreme brachyfacial types with short alveolar and crown
height dimension
• Partially erupted teeth in young adolescents
• Crown heights diminished by excessive wear, trauma or
restorative work
• Diminutive teeth i.e. peg laterals

Additional treatment plan considerations
Changes induced by lingual appliance can be categorized
Vertical plane A-P plane Transverse plane

Changes in Vertical plane
Most immediate & readily
apparent appliance induced
change
In Dolicofacial types
Bite opening mat not be desirable
Use of high pull headgear
To maintain posterior control
BITE OPENING

Changes in anteroposterior plane
B’coz of vertical opening &
rotation (down & back) of
mandible
Treatment plan for Class II correction must be thoroughly
analyzed. Options to consider are:
 Maxillary 1st
bicuspid extractions
 Differential extractions of max. 1st
bicuspids & mand.
2nd
bicuspids
 Headgear therapy
 Surgical correction
Lingual appliance induces
Class II tendency

Changes in transverse plane
Effects of lingual appliance to be considered in transverse
plane are:
Tendency to cause mesiobuccal molar rotation
Expansive nature of the appliance
Intermolar dimension –imp. to control

TMJ CONSIDERATIONS
Relief of joint symptoms following lingual appliance placement
Disarticulation of posterior interferences
 Creates freedom of movement of locked
mandible
 Changes in muscle position & length due
to different posturing of mandible

Esthetic concerns when treating extraction case
• Xn
space (1st
bicuspid )
 Temporary pontic placed in the extraction space
 Pontic reduced in width until space is inconsequential
Temporarily defeats esthetic
advantage of invisible braces
Psychologically traumatic to the
Patient

Temporary bonded pontics

GUIDELINES FOR CASE SELECTION
Ideal Lingual cases
NONEXTRACTION CASES :
 Deep bite Class I mild crowding ,good facial pattern
 Deep bite Class I with generalized spacing
 Deep bite, mild Class II, good facial pattern
 Class II Div 2 with retruded mandible
 Cases requiring expansion
 Consolidation (diastema cases)

• EXTRACTION CASES :
Class II Max.1st
bicuspid & mand. 2nd
Maxillary 1st
Mild double protrusions with four 1st
bicuspid extractions ,where in anchorage
is critical

DIFFICULT LINGUAL CASES
• Surgical cases
• Class III tendencies
• Class II four 1st
• Mesiofacial patterns &/or moderate mand.
plane angle
• Cases with multiple restorative work

CASES CONTRAINDICATED FOR LINGUAL THERAPY
 Acute TMJ dysfunction
 Mutilated posterior occlusions
 High angle / dolicofacial patterns
 Extensive anterior prosthesis
 Short clinical crowns
 Critical anchorage cases
 Severe Class II discrepancies
 Poor oral hygiene or unresolved periodontal
involvement
 Unadaptable or demanding personality types

APPLIANCE PLACEMENT
• Bracket placement & tooth position
• Direct lingual bonding
• Critical aspects of lingual bracket
positioning
• Indirect bonding technique
• Cross-over technique

• Proper bracket positioning must be
planned to :
 Compensate for tooth form & shape
 To alter tip, in-out & torque
 To change bracket position when planned
movement doesn’t occur

BRACKET PLACEMENT & TOOTH POSITION
• Small variation in distance of bracket from incisal
edge effects:
 Vertical position of tooth
 In –out relationship

• Bracket placed at same height on teeth of different
labiolingual thickness
• Brackets will be at different distances from labial surfaces &
will position teeth irregularly labiolingually

 As the bracket is moved gingivally or occlusally
Slope of lingual aspect increases or decreases
Torque angulation changes

 Brackets placed at same vertical height on lingual slopes
that have different angulations
Located at various distances from the incisal edge

DIRECT LINGUAL BONDING
 A close evaluation of tooth thickness & slope of lingual
surfaces must be made
 Bracket locations are marked on the teeth on the model
 One must align the bracket slot at a height from the cusp
tip or incisal edge to establish a flat occlusal plane
 Height gauges ,as currently used in direct labial
bonding ,proved to be inaccurate for lingual height
determination

Why bracket placement in LO is so critical ?
• Decreased arch radius
• Decreased Inter bracket distance
• Compound lingual geometry
• Highly variable tooth morphology
• Limited access & visibility
 Make accurate
compensating
bends exceedingly
difficult
Indirect bonding is therefore
essential with lingual orthodontics

INDIRECT BONDING
• Why Indirect bonding preferred in LO ?
• Indirect bonding Vs Direct bonding
• Case preparation for indirect bonding
• Impression taking
• Laboratory procedures
• Chair side procedures
• CLASS system
• Thickness measurement with DALI program

Historical perspective
• Indirect bonding of orthodontic brackets
initially gained some popularity as a result
of Drs. Silverman & Cohen.

Why indirect bonding preferred in LO ?
 Irregular lingual tooth morphology – Requirement for
custom contouring of lingual bracket bases
 Custom measurement for selection of appropriate bracket
base thickness & torque
 Practitioner’s lack of familiarity with lingual tooth
morphology
 Difficult to obtain a direct line of sight for bonding on
lingual surfaces
 Increased accuracy is required in bracket placement

Indirect bonding Vs Direct bonding in terms of
bond failures
 Zachrisson (1978) reported greater bond failure rate with
indirect bonding then with direct bonding .
 Aguirre et al (1982) Found the reverse to be true with
indirect bonded brackets showing a smaller of bond failures
than direct bonded brackets
Differences if any b/w the two techniques can be attributed
to the following factors:
 Closeness of the fit of the bracket base to the tooth
surface
 Undisturbed setting of the adhesive

CASE PREPARATION FOR INDIRECT BONDING
 Pt’s first receive thorough scaling & prophylaxis
 Unusually large cingulae or rudimentary cusps often
seen on max. cuspids-should be reduced prior to taking
impressions
 Unusually concave lingual surfaces-can be filled with
composite
 Lingual surface of PFM crowns often has metallic coping
exposed –must be replaced with plastic jacket crown
 Common occurrence of Dens-in-dente on lingual surface
of max. lateral incisors – restored with composite
 Procedures that may cause tooth movement i.e.
separation, extractions ,removable appliances etc.
should be postponed until after bondingwww.indiandentalacademy.com

IMPRESSION TAKING
 Alginate impression are taken with a rigid well fitting
tray
 Impression must reproduce all teeth & palate accurately
 Impression must reproduce lingual surfaces accurately
with clear definition of the gingival crest
 Models are poured immediately in dental stone
 Drying the gingival sulcus with air & wiping the alginate
into the lingual surfaces will aid in providing clear, well
defined impressions

LABORATORY PROCEDURES
• Determination of lingual bracket heights
• Indirect bonding techniques
• Bonding of the brackets on the stone
model
• Bracket placement in crowded cases
• Fabrication of transfer trays

Determination of Lingual bracket heights
• Lingual bracket slot heights are based
upon the shortest lingual crown available
in both the anterior & posterior segments
• Optimum bracket placement criteria
include:
 Clearing the gingival crest by 1.5mm
 Allowing 2mm b/w incisal edge & bracket
bite plane on max. incisors

TARG- Torque angulation reference guide
 An apparatus developed
by Ormco in 1984 for lingual
bracket bonding
 Advantages :
 Allows to bond the
brackets in the lab at
accurate distance
 Preprograms torque &
angulation before treatment

TARG
Consists of
Modified dental
surveyor
Torque &n angulation
Gauge

Procedure for using TARG
• Crown long axis is marked
on labial surface
• Torque gauge – constructed
for each type of tooth from an
average buccal anatomy
• Model is tipped on a swivel
base until the long axis of
labial face of tooth aligns with
the specific gauge curvature
Torque
gauge

• Bonding level is determined
by lab. technician
•The stylus connected to a
dilatometer is lowered the
specific distance as
determined by initial survey
• Reference mark is made
on the model yielding both
bracket slot height &
angulation

• TARG horizontal blade is
engaged in the bracket slot
,moved towards the model at
the bonding level
•Bracket is bonded to the
plaster with composite – fills the
gap b/w lingual tooth surface &
metal base of the bracket
• A new resin base which
accurately follows the lingual
anatomy of each tooth is
integrated to each bracket

LIMITATION OF TARG
 TARG doesn’t take into
account the labiolingual
thickness of the teeth

INDIRECT BONDING TECHNIQUES
• Several indirect bonding techniques have
proved reliable in clinical practice they
differ in the way:
 Brackets are attached to the model
 Type of transfer tray
 Adhesive or sealant employed
 Whether segmented or full bonding is
used

INDIRECT BONDING TECHNIQUES
Indirect bonding with silicone
transfer trays
Indirect bonding with double
sealant technique

Bonding of brackets on the model
• Use of water soluble
temporary cement
(Sugar Daddy)
• Dissolves when
indirect transfer tray is
removed
• Leaves a gap b/w
bracket & tooth –filled
by using appropriate
bonding resin
• Use of filled resin
• Fills the gap b/w
lingual tooth surface
& bracket base
• New resin base is
integrated into each
bracket
• Excess adhesive is
removed accurately
on each bracket

Bracket placement in crowded cases
• Centering the bracket on the
labiolingual axis of the tooth
• Overcorrecting the bracket
position by moving it mesially or
distally
• Initially positioning the bracket
at the best fit & once rotation is
partially corrected change the
position of the bracket

FABRICATION OF TRANSFER TRAYS
• Function : Allows us to transfer the brackets which
have been bonded on the malocclusion to
the pt’s mouth.
Materials required
 Silicone material –
low viscosity & high
viscosity( putty material )
 Vacuum formed tray
made using Bioplast &
Biocryl

Silicone transfer tray system
 Low viscosity is used to encapsulate the brackets.
 Low viscosity is then covered with a high viscosity
silicone – has high strength.
After the material has set – trays are kept in water for
10 min.
Dental midlines are marked on the trays.

Silicone transfer tray system

Vacuum formed transfer tray system
• Two tray processed on Biostar machine .
•The inner tray is 1.5mm Bioplast & outer tray is 1.0mm
Biocryl . This combination gives the best clinical result.

Chair side procedures
• Prebonding procedure
• Preparation of teeth for bonding
• Bonding of brackets
• Rebonding single brackets

Prebonding procedure
• Before beginning bonding procedure ,the
indirect transfer tray is tried in to ensure
complete seating.
• Case is not bonded if the fit of the tray
is questionable .

Preparation of teeth for bonding
Includes Pumicing & Etching of teeth
• Gingiva must be firm & non hemorrhagic
• While pumicing –pumice is carried into the gingival sulcus
• When etching – soln. is applied up to the gingival crest
• Exposed Cementum should not be contacted with etching
soln.
• Thorough rinsing –air water spray is directed into sulcus
• Bonding sealant –applied as close as possible to gingival crest
Instructions to be followed

Bonding of brackets
Brackets can be bonded using
Two component system No mix system
Unfilled resin liquid

Bonding procedure using adhesive paste
• In case of two component system – Mix adhesive , load it in
syringe & apply to the bonding bases
•Seat the tray on the prepared arch & hold with firm pressure
for about 3min.
•Remove the tray after 10min. Tray may be cut longitudinally
or transversely to reduce the risk of bracket debonding
• Complete the bonding by careful removal of the
adhesive flash

Indirect bonding technique

Bonding procedure using Unfilled resin
• Liquid resins A & B are dispensed separately
• Resin B is applied to the tooth surfaces
• Resin A is applied to the bracket pads
• Seat the tray on prepared arch & hold firmly for 2-3 min
• After trays have been removed –excess resin is removed

Advantages of using Unfilled resin
• Since the resin is unfilled – excess resin
flakes off easily with a scaler or dental
tape
• Bracket removal is easier
• Reduced chair side time
• Risk of moisture contamination is greatly
reduced

REBONDING OF SINGLE BRACKETS
 By using the initial
transfer tray
 Original bracket is reused
– customized for a particular
tooth
 Original tray is sectioned
for the individual tooth
 Bracket is replaced in the
tray
 Tooth is prepared &
rebonded
 By redoing an individual
bonding tray in the lab
 If original tray is not suitable
for reuse or
 First time bracket placement
 Small single tooth silicone
tray is made
Single bracket is then indirect
bonded

Indirect bonding with
double sealant technique
Indirect bonding with
silicone transfer trays
• Method of
attaching
brackets to the
model
• Type of
transfer tray
• Bonding of
brackets
Use of water soluble
adhesive
Uses silicone material
Use of either two paste
system or No mix
system
Use of adhesive paste
rather than a temporary
adhesive
Vacuum formed trays
made using Bioplast &
Biocryl
Use of unfilled resin –
using Part A & Part B
liquid resins

FILLION’S LINGUAL INDIRECT BONDING SYSTEM
 Thickness measurement
system ( adapted from TARG)
DALI program

TARG with the thickness measurement system
 A caliper is added to the
TARG central axis – two
horizontal blades
 Records the thickness (width
of the teeth with bracket ) of six
ant. teeth
 Resin is applied to the bracket
base.
 Bracket placed on the blade-
moved towards the plaster until
selected thickness appears on
the screen

Bracket bonding using TARG with thickness
measurement system
Gap is filled with resin Bracket with a resin pad

Advantages of thickness measurement system
 Eliminates the necessity to prepare a setup & bonding
is performed directly on the malocclusion model
 Standardization of thickness – Avoids all 1st
order
bends except the one b/w cuspids & bicuspids & b/w
bicuspids & molars
 A copy of the arch form can be made – helps the
clinician to bend the 1st
arch wires of treatment

DALI PROGRAM
Dessin Del Arc Lingual Informatise OR
Computerized drawing of the lingual arch wire
Helps us to obtain a detailed drawing of the lingual arch wire
with all teeth perfectly aligned
Measurement of tooth widths Help of a computer

DALI PROGRAM – Procedure
 On the arch form , the teeth & their brackets take their
individual positions
 Once all teeth are represented the program traces a “ best
fit” arch wire to the triangles creating ideal arch form
A
B
C
A. Width of the tooth
B. Width of bracket
C. Distance b/w bracket
slot & labial tooth
surface
DALI program cannot work
Without thickness
measurement system

Advantages of DALI program
 Permits us to obtain an extremely accurate tracing of the
finishing arch wire at 1:1 ratio
 Allows us to know with a very high accuracy (with 0.1mm)
the width of the 1st
order bends
 Allows us to know the ideal arch shape needed to achieve
a good occlusion
 Permits us to preform arch wires with great precision
 Not necessary to coordinate the arch wires during
treatment

CLASS SYSTEM
Customized lingual appliance set up service
Features :
 Offers a method of lingual bracket placement – takes into
account anatomical discrepancies in lingual surfaces of the
teeth.
 Ideal diagnostic set up is made from a duplicate set up
model of pt’s original malocclusion.
 Brackets are placed on diagnostic set up using
composite adhesive
 Brackets are next transferred back to malocclusion cast
 Transfer trays are fabricated

CLASS SYSTEM

Constructing an Ideal diagnostic set up

Bonding brackets on ideal diagnostic set up

Transferring the brackets to malocclusion cast

Fabrication of transfer trays

Removal of transfer trays & fabrication of templates

BUCCAL & LINGUAL MOLAR ATTACHMENTS
 Bonding of mandibular posterior teeth with use of
buccal segmental wires & lingual attachments
 Reasons :
 Short lingual crown height of mand. 1st
bicuspids
 Lower bicuspids aren’t visible on most pt’s- can
be bonded without losing the invisible aspect of
appliance

CROSS -OVER TECHNIQUE OR
BUCCOLINGUAL SEGMENTAL TECHNIQUE
 Refers to the use of labial appliances (or combined
labial & lingual ) in posterior segment along with lingual
appliances in the anterior sector
 Offers best features for Esthetics & anchorage control

Lingual 2

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