Lingual Orthodontics

Didier Fillion

MoscowApril 16-17 2006

Didier FILLION

has practiced lingual orthodontics exclusively in Paris since 1987. and in London since 1997.He belongs to the French Orthodontic Society, the American Association of Orthodontists and the American Lingual Orthodontic Association. He is founder member and Honorary President of the French Lingual Orthodontic Society, founder member and Honorary Secretary of the European Society of lingual Orthodontics, Founder member and President of the British Lingual Orthodontic Society. He is founder member and President of the World Society of Lingual Orthodontics .

He is president and co-organizer of the first International Lingual Orthodontic Congress held in Paris (1991), scientific president of the second meeting of the European Society of Lingual Orthodontics (Monaco 1996), and vice-president of the first International Congress of Lingual Orthodontics (Tokyo 1999) . He

is course director of the two - year program in lingual Orthodontics at René Descartes Paris-V UniversityHe has held courses in lingual orthodontics around the world (USA, Japan, Sweden, Spain, Portugal, Denmark, Germany, Italy, Korea, England, Brazil, Chili, Russia, Thailand, England, Emirates, Saudi arabia, …) and periodically conducts hands-on in-office courses in English. He regularly has foreign colleagues come to in his office to train in order to increase their knowledge and clinical experience. He invests a lot of his time and energy in order to improve the technique and design new materials.Dr Fillion is not only considered to be a leading lingual orthodontic expert but, today, he is the only orthodontist in the world to maintain a full - time lingual orthodontic practice in Paris and London.

Please, feel free to contact me:

E-mail: smile@drfillion.com

Introduction

The recent increase in the popularity of lingual orthodontics in adult patients is due to the appliances not being visible during treatment. This allows a large number of patients to be treated who would otherwise refuse to wear more visible labial braces.The advantage of lingual appliances over other aesthetic appliances, such as Invisalign, is that it can treat all kinds of malocclusions irrespective of the severity of the malocclusion. It may also be used successfully in the management of complex restorative cases where orthodontic treatment merely acts as a step in providing alignment, correct angulation and correct spacing for the successful placement of bridges and implants.

However, following the placement of lingual appliances there is an adaptation period for the patient to overcome the initial discomfort. The main problems experienced are soreness of the tongue and disturbance in speech. These factors may cause an initial reluctance to accept wearing lingual braces (1, 2, 3).

A new generation of lingual bracket, STb, appears to overcome these initial difficulties, increasing patient comfort and producing results to a high clinical standard.

Description of the Appliance

STb brackets take their name from Dr. Scuzzo and Dr. Takemoto, who have spent many years developing their new bracket based upon personal clinical experience.The most significant change in design is the size of the bracket. The new STb lingual brackets are smaller and more closely adapted to the lingual vestibule. The dimensions of the incisor and canine brackets are 2.5mm (width) by 1.5 mm (thickness). The premolar and molar brackets have a thickness of only 1.5mm (Fig 1a&b).

Figure 1a & 1b: STb brackets for the maxillary incisors and canines with an antero-posterior thickness of 1.5mm

The shape of the bracket has also been dramatically changed. There are three small wings (two occlusal and one gingival) and a 0.018” x 0.025” slot for the arch wire. The absence of a hook and bite plane further reduce the overall dimensions of the bracket leading to greater patient comfort.

Fig 2a: A frontal view of the to compare the differences in thedimensions of the new STb and Ormco-Kurz 7th generation bracket

Figure 2b: A visual comparison of the differences in the dimensions of the STbbracket (left side) and the 7th generation Ormco-Kurz (right side) bracket for themaxillary arch

ComfortThe reduced dimensions and more round edges of the new STb bracket spectacularly reduce patient discomfort when the brackets are first placed.A previous study investigating patient comfort following placement of the 7th generation Ormco-Kurz bracket emphasised that there is a significant adaptation period for patients.After three months of treatment, when asked about the discomfort caused by the appliance, 36% of patients responded that the period of adaptation was initially greater than 3 weeks.Disturbance of speech was still an issue for 18% of patients and difficulty in eating for 12% of the patients (4).On repeating this study in patients who had STb brackets placed only one month previously the results were considerably different (Table 1a- 1f). There appears to be a shorter time for patient adaptation when asked about comfort. The irritation to the tongue is very clearly diminished. The ability of the patients to endure the discomfort also appears to be improved with the new smaller brackets suggesting they are more comfortable.

SpeechSpeech disturbance is no longer an issue at the end of the first month of treatment. A video demonstration, at the 6th Congress of the European Society of Lingual Orthodontics, showed that there was no perceptible impairment of speech immediately after placement of the new STb brackets. The patients appeared quite comfortable and confident in repeating the phrase “She sells sea shells on the sea shore”.The overall patient perception of greater comfort of the new brackets suggests that patients with lingual brackets concentrate, unsurprisingly, on the fact that there is anincreased difficulty in eating when the appliances are placed. This problem is not confined to patients with lingual appliances only, as this is a common complaint ofpatients with labial appliances at the end of the first month of treatment.

Another encouraging outcome of this survey is that patients are less disturbed in their social and professional working lives with the new brackets after just one month.

Table 1a: Patient adaptation to STb brackets (after 1 month) compared to the 7th generation Ormco-Kurz (after 3 months).

Duration of adaptation Ormco Kurz (after 3 months)

STb ( after 1 month)

Less than 1 week 9% 45%2 weeks 29%

36%3 weeks 26% 19%Greater than 3 weeks 36% 0

Table 1b: Patient perception of the adaptation period to STb brackets (after 1 month) compared to the 7th generation Ormco-Kurz (after 3 months).

How did you find thisadaptation phase?

Ormco Kurz (after 3 months)

STb ( after 1 month)

Easily Bearable 27% 36%Moderatley Bearable 45% 64%Difficult 27% 0%

Table 1c: Factors patients found difficult after bracket placement. A comparison of STb brackets (after 1 month) compared to the 7th generation Ormco-Kurz (after 3 months).

What was the mostuncomfortable aspect?

Ormco Kurz (after 3 months)

STb ( after 1 month)

Irritation to the tongue 44% 25%Difficulty in speech 36% 0%Difficulty in chewing 20% 75%

Table 1d: Disturbance in the work place caused by STb brackets (after 1 month) compared to the 7th generation Ormco-Kurz (after 3 months).

Do the appliances Ormco Kurz (after 3 STb ( after 1 month)

disturbyour professional activity?

months)

2 weeks 12% 0%

Table 1e: Disturbance in social activity caused by STb brackets (after 1 month) compared to the 7th generation Ormco-Kurz (after 3 months).

Do the appliances interferewith your social activity?

Ormco Kurz (after 3 months)

STb ( after 1 month)

Less than 1 week 6% 0%

Table 1f: Disturbance in speech caused by STb brackets (after 1 month) compared to the 7th generation Ormco-Kurz (after 3 months).

Are you able to speaknormally?

Ormco Kurz (after 3 months)

STb ( after 1 month)

18% 0%

Maintenance of Oral Hygiene

Difficulty in maintaining a high standard of oral hygiene has been widely experienced by patients wearing fixed lingual appliances. Generally all patients are encouraged to see a hygienist every three months during treatment, if possible with arch wires removed.The STb brackets appear to have greatly facilitated maintenance of a high standard of oral hygiene. Clinically less gingival inflammation has been noted around the bracket base. This may be due to three factors in the design of the bracket:1. The small size of the brackets mean that there is an increased inter bracket space which may be more easily cleansed (Fig 3 &

4)2. The brackets protrude a smaller distance from the tooth and appear to trap less food.The absence of a hook may contribute to this observation.3. The smaller size of the bracket base means that they may be positioned away from the gingival margins making it easier to clean this area and reduce the amount of gingival inflammation from plaque accumulation.

Fig 3: A comparison of the lateral profile of the STb and Ormco-Kurz incisor bracket.Note that the STb bracket is bonded slightly more incisally so that it lies away from the gingival margin. The absence of a hook prevents a natural food trap and facilitates brushing.

Figure 4: A comparison of the lateral profile of the STb and Ormco-Kurz premolarbracket. As before the brackets is bonded more occlusally. Also, the lower profile and absence of a hook contributes to increased patient comfort.

Efficient treatment and reduced treatment time

The benefits to the patient with respect to comfort are easily demonstrated, however, the question that may arise is, “How effective are these brackets clinically?”

The benefit of increased inter bracket distanceThe lingual surface of the teeth has a reduced radius of curvature compared to the labial surface. With the conventional Ormco-Kurz brackets, due to their size, there is very little space between the brackets when bonded correctly. The effects of the reduced inter bracket width and decrease in the radius of curvature means that it is more difficult to engage the initial aligning wire. An undesirable high force if the arch wire is fully engaged may increase patient discomfort and lead to fracture of the appliances.The smaller size of the STb brackets tends to allow easier arch wire engagement of a aligning wire of similar dimensions as the inter bracket distance is reduced and furthermore, this leads to a reduction in the forces applied to the teeth (Fig 2b).The ability to engage the arch wire completely into the slot means

that three dimensional control of tooth movement is achieved much earlier in treatment.

Placement of metallic ligaturesThe utilisation of metal ligatures is recommended in orthodontic treatment as it guarantees that the arch wire is placed firmly in the bracket slot maximising the effect of the wire on the bracket and the tooth. This procedure is laborious in the conventional lingual technique using the Ormco –Kurz brackets.The placement of metal ligatures has been made significantly easier with the STb brackets allowing the initial aligning phase to be completed more easily (Fig 5).

Figure 5: The increased inter-bracket distance allows the wire to be fully engaged into the bracket slot at the start of treatment

Reduced friction and light forcesThe utilisation of metallic ligatures and light 0.010” or 0.012” nickel titanium wires means that the forces applied to the teeth and frictional resistance to movement is reduced (Fig 6). The significance of these two factors is that there is more rapid

alignment of the teeth with reduced patient discomfort (Fig 7a-c)

Fig 6: The metal ligatures allow the wire to be fully engaged into the bracket slot and reduce the friction for sliding mechanics

Fig 7 (a) First appointment – appliances bonded; (b) 6 weeks after appliances bonded; (c)12 weeks after the appliances bonded.

Greater ability to bond severely crowded teethA limitation of the increased dimensions of the Ormco- Kurz brackets is that it is not always possible to bond all the teeth at the start of treatment in a very crowded dental arch. This means that placement of some brackets may need to be deferred, increasing the time of the initial alignment phase of treatment and the overall treatment time.The reduced bracket size of the STb allows all the teeth to be bonded at the start of treatment reducing the duration of the initial phase of treatment and subsequent treatmenttime (Fig 8).

Fig 8: Despite the rotations of the incisors it is possible to place all thebrackets at the initial appointment.

Use of elasticsThe small size of the STb bracket and the absence of a hook do not preclude the use of intra-oral elastics. Kobayashi ligatures may be tied around the brackets to allow the patient to use intra-oral elastics when it is necessary clinically (Fig 9).

Fig 9: Intermaxillary elastics may be attached to the Kobayashi ligatures

Laboratory procedure

1-Simplified techniqueWhen torque control is not needed, a simplified technique can be used. This technique uses only the initial model.A line is traced on each tooth at the same distance from the edge and the base of the brackets are bonded on this line. Then a silicone transfer tray is used to make a full arch tray or individual trays.With this technique, only round wires will be used.

Fig 10 Simplified technique

2-B.E.S.T. technique ( Bonding with Equal Specific Thickness) Fillion-1987

This technique allows to place the anterior brackets at the same distance from the labial side and consequently decrease archwire bending.

B.E.S.B.E.S.T. T. systemsystemBBonding with EEqual SSpecific TThickness

Fig 11 : Equalization of the distance from slot to labial side by modifying the thickness of each resin pad.

Two devices are necessary : The T.A.D. ( Torque Angulation device) to orientate the teeth in space and the B.P.D. ( Bracket Positionning device) to place the brackets at a specific distance from the labial side by modifying the thichness of each resin pad. This technique must be used for all extraction cases and for non-extraction cases when torque control is necessary .

Fig 12 : Bracket Positionning device

Fig 13 : STb brackets with resin pad

3-Transfer Tray

Fig 14 : Resin Reinforced Silicon transfer tray

Bonding procedure

Because of the micro-sandblasting (25 microns of Aluminium Oxyde - Airflow Prep K1- EMS), every surface can be bonded : enamel, metal, amalgam, ceramic. Thanks to the Dry FieldSystem ( Nola Specialties, Inc.) every lower arch can be bonded in one time.Today bondings can be done with Maximum Cure ( Reliance Orthodontic product ),Resin Reinforced Glass Ionomer Cement ( Fuji LC GC), FlowTain( Reliance Orthodontic products) with OrthoSolo ( Kerr ) as liquide adhesiveThe bonding procedure is similar to the procedure used to bond Ormco- 7th generation brackets. Otherwise, it is recommended to use unfilled resin or to use a minimum of bonding material to avoid excess material blocked berween enamel and the occlusal part of the bracket. This excess could prevent from ligating due to the size of the bracket.

Fig 14 : Bonding with Nola on Lower arch

Archwire sequence

1- Non-extraction case

•If any torque control necessary , only 2 or 3 wires will be used :Alignment-Leveling .010 - .012 - .014, NiTi with

advancement loop if necessaryDetailing .016 TMA

•With torque control :Alignment-Leveling .010 - .012 - .014 - .016 NiTiTorque control .017 x 017 CuNiTiDetailing .0175 x .0175 TMA

2- Extraction case

Alignment-leveling .012 - .014 NiTiPartial cuspid retraction .016 x .016 S.S.Alignment-Leveling .014 - .016 NiTiTorque control .017 X .017 CuNiTi

0175 X .0175 TMAEn Masse retraction Combination wire .018

x .025 / .018 Detailing .016 TMA - .0175 x .0175 TMA

Ligating It is essential to use metallic ligatures specially at the beginning of the treatment with .010 and .012 NiTi. ( .08 or .09 ). In case of severe crowding and rotation, it is useful to pull the wire with a dental floss to engage the wire in the slot when ligating.

Efficiency of » Low-Force / Low-Friction » system

.012 NiTi 2 months later

.012 NiTi 2 months later

STb Bracket detail

STb bracket with 40° torque STb bracket with 55° torque

Torque Ang.Rot

Central/Lateral/Canine Upper +40° 0Central/Lateral/Canine Upper +55° 0Central/Lateral/Canine Lower +40° 0Premolars +11° 01st Molar Upper Left +10° 0 10° 1st Molar Upper Right +10° 0 10°1st Lower Molar 0° 0 02nd Molar Upper Left +10° 0 10°2nd Molar Upper right +10° 0 10°2nd Lower Molar 0° 0 0

.014 NiTi with advancement loop

.014 NiTi is used with advancement loop to correct anterior crowding

Retraction Mechanics

.018x .025 / .018 S.S. CombinationWire Sliding MechanicsA Combination Stainless Steel wire is used for “en masse “ anterior retraction.The six anterior teeth are tied together as a unit and then the 2nd premolar to the 1st and 2nd molars with a figure-eight .09 steel ligature after inserting the wire.An elastic thread is set from 2nd premolar to lateral .Options:

• the figure-eight ligature is placed before inserting the wire and then an individual ligature is placed on each tooth after inserting the wire.

Sliding Mechanics with Combination Wire

Frictionless Mechanics

Frictionless mechanics can be used with Bracket/Tube ( Fillion) bonded on 1st molars.

A curve of Spee and an anti-bowing effect form are incorporated to the Combination wire.1st option: FM1NiTi springs are used in place of elastic thread from premolar to lateral.

2nd Option: FM2Lever arms are set between canine-lateral or between lateral-central and between 2nd premolar- 1st molar.

3rd Option: FM3Lever arms are set between canine and lateral when mini-screws are used for anchorage.

Frictionless Mechanics with lever arms: FM2