Lingual appliances1. Developed in 1975 by Kruz USA and Fujita Japan

2. It is mainly fully programmed appliance (means that all SWT feature are involved)

and either semi or fully customized to the patient.

3. Wire sequence smaller than usual because of the reduced interbracket distance

(012, 016, 16*16 NITI then 16*16 SS)

4. It is considered a hybrid slot orientation appliance (Ribbon arch slot –vertically

oriented placement of the AW similar to Begg brackets- in the anterior teeth and edgewise

slot- horizontal oriented placement of the AW similar to Angle Edgewise brackets- in the

posterior teeth)

Advantage

1. Aesthetic

2. Less enamel decalcification

3. Efficient in OB reduction

Disadvantages

1. Cost

2. Accessibility

3. Speech problem and discomfortibility

4. Cleaning problem

5. Variable lingual morphology make bracket fitness problematic

6. Canine offset which need mushrooming of the AW.

7. Reduced interbracket distance causing reduction in the AW flexibility. This might

be associated with more OIIRR.

8. Finishing and torque control very difficult and need precision since any error could

be exaggerated because the force of application nearer the centre of resistance than

conventional labial bracket system.

Types of lingual orthodontic systems

1. Two dimensional system (standard or semi PEA system)

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2. Three dimensional system (fully PEA system) like STB system

3. Custom made (incognito)

4. Ready made

5. Semi customized

6. Metal

7. Ceramic

8. Conventional ligation

9. Self-ligation (Self-ligating slots ease placement of the wire, full engagement,

reduces friction, reduce chair side time and create efficient initial alignment.

Features of incognito

1. Incognito slot size is 0.018 × 0.025 inch because of the reduced interbracket

distance.

2. Feature of the bracket system are: Fully custom made bracket, Fully custom made

wire, Thin profile leading to little discomfort

3. Incognito arch wires are used in a ribbon-wise configuration. A vertical slot

insertion in the anterior region from canine to canine and a horizontal slot insertion in the

lateral segments.

4. Order bends: The vertical height, angulation and torque are pre-set into each

bracket so the need for maximum individuality is met and the patient’s individual

prescription is designed into the brackets. Only the first-order information is delivered via

the arch wire. However, because of close proximity to the centre of rotation, minor torque

problems are apparent immediately and mainly appear as a vertical discrepancy or in-out

problem.

5. A bracket for the unerupted canine can be made from the beginning of treatment

by mirroring the image of the erupted canine. Recently the manufacture relies on the use

of constructed virtual template of the unerupted teeth obtained from at least 0.3mm voxel

CBCT!!!!!!!!!!!!!!!!!! Too much radiation (Mohammed remember for each 1cm zone of

FOV with a 0.4mm voxel size and 20 mAm, there is about 10mSv of effective dose and in

case of 0.3mm voxel size the radiation could be double that of 0.4mm voxel). However

this philosophy had been described by Elangbawi and Cross, 2013to construct a physical

template for transplanted tooth.

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6. With the Incognito system, an indirect bonding protocol is used for the initial

bond-up; extractions are usually only carried out after the appliance has been bonded

because any change in position of the teeth either side of the extraction site could prevent

the tray from seating correctly.

7. Occlusal pads helps in: providing greater bond strength, act as bite plate, allowing

for a direct rebonding procedure without the need of transfer trays or jigs in case of

debonding.

8. Double cable mechanics consist of two power chains, a transparent one running on

the buccal side of the teeth and a grey one running on the lingual side. This might help to

control lingual rolling and fasten the movement.

9. Deep bite cases to instantly improve the vertical dimension. With Incognito,

vertical control, as in levelling the curve of Spee or controlling the overbite, is clinically

more efficient than in edgewise labial or conventional lingual appliances because with a

ribbon-wise configuration the big dimension of the archwire (0.025 inch superior-

inferiorly) corrects the vertical plane and also because the close proximity of the force

application to the centre of rotation and root as well as the anterior bite effect.

10. To improve anchorage, control splints can be made to lock teeth together.

Advantage of incognito

1. Good outcome compared to conventional (Romano 1999, Ling 2005)

2. No difference in treatment times have been observed with the use of labial and

lingual orthodontic treatment techniques. Treatment goals and treatment planning are also

identical.

A common archwire sequence for Incognito

For a non-extraction case is as follows:

The wires have individual first-order bends in the lateral segments,

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1. Initial wire: 0.014 inch SE NiTi

2. 0.016 × 0.022 inch SE NiTi

3. 0.0182 × 0.0182 inch TMA for finishing.

4. Elastics can be used with the TMA wire for a short time period; if elastic wear is

more prolonged then a 0.016 × 0.024 inch SS is necessary before the finishing wire.

For an extraction case,

The wires are straight in the lateral segment to allow for sliding during space closure in the

posterior region:

1. Initial wire: 0.014 inch SE NiTi

2. : 0.016 × 0.022 inch SE NiTi.

3. 0.016 × 0.024 inch SS for space closure

4. Finishing wire: 0.0182 × 0.0182 inch TMA, with individual first order bends in the

lateral segment.

Finishing stage in lingual orthodontics

A major advantage of the lingual appliance over the labial appliance at this stage of treatment is the absence of brackets, wires, and some- times gingival hypertrophy masking the labial surfaces and possibly misleading clinical judgment.

The difficulties encountered at the finishing phase of lingual orthodontics derive from the following three main sources:

1. Patients’ characteristics in particular adult patient who seeks lingual appliance treatment. For instance, their dentition is more comrompised and they are more demanding

2. Anatomy of the lingual surfaces

3. Mechanics of lingual treatment

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