New orthodontic treatment with lingual b-a&et mushroom arch wire appliance

Kinya Fujita, D.D.S., D.D.Sc.* Yokosuka, Kanagabaa, Japan

P atients have expressed a desire for a nearly invisible orthodontic appliance that can be placed on the lingual surface of the teeth for improved esthetics or prevention of trauma during exercise. It is difficult to solve these problems with the conventional multibracket type of appliance. In such cases the treatment technique to be described here may be worthy of consideration.

*Assistant Professor, Department of Orthodontics, Kanagawa Dental University.

Fig. 1. Lingual bracket and lock pin and O-ring elastics for fixation.

Fig. 2. Lingual bracket bonded and mushroom arch wire appliance applied lingually at the dental arch.

0002.9416/79/120657+19$01.90/0 0 1979 The C. V. Mosby Co. 657

5% Fujita

Fig. 3. The result of analysrs of the pronunciation by means of a Real Time Third Octave Analjizer jrhe white bar shows 1 kiloherz) showed that the a and i represent the sounds “a“ and 7” recorded before the application of the lingual bracket mushroom arch wire appliance. a-l and i-l represent the sounds recorded on the first day of treatment with the appliance application; a-4 and i-4 represent the sounds on the fourth day; and a-6 and i-6 represent the sounds on the sixth day.

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Fig. 4. The u and e represent the sounds ‘II” and “e” recorded before the application of the lin! bracket mushroom arch wire appliance. u-l and e-l represent the sounds recorded on the first dz treatment with the appliance application; u-4 and e-4 represent the sounds on the fourth day; and and e-6 represent the sounds on the sixth day.

gual ly of u-6

Fig. 5. Theo represents the sound “0” recorded before the application of the linguai bracket mtishroom arch wire appliance. o-l represents the sound recorded on the first day of treatment with the appliance application, o-4 represents the sound on the fourth day and o-6 represents the sound on the sixth day.

This new technique was developed for orthodontic treatment with the concept of moving each tooth in three dimensions from its lingual and palatal sides. L-a The effects and side effects caused by this technique were studied.

Since 1975 I have manufactured, on a trial basis, an appliance designed according to the above concept and studied its clinical use. This new orthodontic treatment technique was found to be superior, from an esthetic standpoint, to the conventional treatment techniques with multibracket appliances. Furthermore, with regard to the prevention of trauma from the appliance, it was found that this technique is very useful in the treatment of patients who participate in such sports as football and judo. The findings obtained through the study of this treatment technique in three cases with different characteristics (extensive corrective orthodontics, limited corrective orthodontics, and combination treatment by the concurrent use of this new technique and the conventional treatment techniques) are presented. Specifically studied were the clinical effects of the appliance and changes in the patients’ pronunciation produced by this new treatment technique.

Appliance

A new bracket, lockpin, and orthodontic wire of a specific design were developed. Bracket. For the lingual bracket, the opening of the slot was set on the occlusal surface

of the teeth in order to facilitate the fitting of the orthodontic wire and to prevent deforma- tion of the orthodontic wire at the time of insertion into the bracket. The groove for insertion of the lockpin for fixation of the orthodontic wire in the slot was set mesiodistally in the slot (parallel with the orthodontic wire). Furthermore, an auxiliary groove was set in

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Fig. 6. Case 1. Pretreatment facial and intraoral photographs of lPyear-old girl.

62 Fujita

Fig. 7. Case 1. Third month of treatment. Maoral photographs showing that distal movement of maxillary canines and mesial movement of mandibular first molars were induced by the application of the lingual bracket mushroom arch wire appliance.

the occlusogingival direction to facilitate correction of the mesiodistal tipping of the teeth. Lockpin. A stainless steel lockpin was developed for fixation of the orthodontic wire to

the lingual bracket. In addition to the lockpin, conventional ligature wire and O-ring elastics may be used for fixation.

Orthodontic arch wire. The orthodontic arch wire, which is fixed to the lingual surface of the teeth, is formed like a mushroom. Conventional arch wires are bent to this new form.

renunciation

One oral function considered greatly affected by this treatment is pronunciation. If any remarkable change is seen in the patient’s pronunciation or if uttering of words is affected by this treatment, the technique will have to be discontinued or fundamentally re- considered.

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Fig. 8. Case 1. Twenty-third month of treatment. Intraoral photographs showing that the ideal mush- room arch wire has already been applied and that treatment is in the course of retention.

The effect of this technique on the pronunciation of vowels by the patient was studied by comparing the patient’s voice before and during treatment. The patients were asked to pronounce the vowels of Japanese (“a, i, u, e, and 0” of the International Phonetic Alphabet), which were then analyzed for the cycles by Real Time Third Octave Analyzer Type 3347 (manufactured by Briiel & Kjaer of Denmark).

The one patient evaluated for pronunciation changes was a 19-year-old Japanese women who had a Class I malocclusion with crowded anterior teeth. The treatment regimen was to extract four first premolars and to proceed with treatment by the new technique. Figs. 3, 4, and 5 show the analysis result for the pronunciation of the five vowels recorded before treatment and on the first, fourth, and sixth days of treatment with this appliance. The patient showed no great effect from the lingual bracket and mushroom arch wire on the pronunciation of the vowels “a and o. ” However, the pronunciation of “i, u, and e” was somewhat disturbed on the first and fourth days. The pronun- ciation of these vowels was back to normal (pretreatment condition) on the sixth day (Figs. 3, 4, and 5).

Fig. 9. Case 1. Posttreatment facial and intraoral photographs of patient at 14 years of age.

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Fig. 10. Case 1. Pretreatment (A) and posttreatment (B) cephalometric and panoramic radiographs.

Case1

Patient Y. A.: a 12-year-old girl, had a Class II malocclusion with crowded anterior teeth, an overjet of 2.5 mm., and an overbite of 1 mm. (Fig. 6). Facial and intraoral photographs, orthodontic study models, and cephalometric, intraoral, and panoramic radiographs were taken. There was nothing unusual in the family history. The patient’s nutrition and growth conditions were good. The maxillary canines were severely crowded and high. Crowding in the mandibular anterior teeth was mild. The teeth were in the normal size range. There was a discrepancy of 12.5 mm. in maxillary arch length and of 3.5 mm. in mandibular arch length. The cephalometric evaluation was well within normal limits (ANB = 3 degrees, FMA = 31 degrees, FMIA = 53 degrees, IMPA = 96 degrees, Y axis = 69 degrees, gonial angle = 127 degrees, interincisal angle = 127 degrees,

Fig. 11. Case 2. Pretreatment facial and intraoral photographs of l2-year-old giri.

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Fig. 12. Case 2. Fourth month of treatment. Intraoral photographs showing that the maxillary anterior teeth have been expanded anteriorly and elongated and that the overbite has already been improved.

esthetic line: upper lip = 1.5 mm. and lower lip = 1 .O mm.). As a result of the analysis, this case was diagnosed as a dental problem.

It was decided that the maxillary first premolars and the mandibular second premolars should be extracted. leaving the maxillary extraction space for the canines and the mandibular extraction space mostly for mesial movement of the first molars.

The treatment equipment used consisted of the lingual bracket mushroom arch wire appliance which I developed. The lingual bracket was applied on the first molar band. Edgewise brackets were bonded on the maxillary anterior teeth, and lingual brackets were bonded on other teeth. As the source of the orthodontic correction force, a loop was bent into the wire at the extraction sites, and auxiliary wires and elastics were used. A 0.016 by 0.016 inch finishing arch was used. The ideal mushroom-shaped arch wire acted as a fixed type of retainer for 6 months following active tooth movement. After the appliance had been removed, the removable retainer was used only at night (Figs. 7 to IO), and good results were obtained. The patient was very cooperative throughout the treatment period, and a good result was obtained. The lingual bracket mushroom arch wire appliance was used continuously for 24 months. This includes active treatment time and passive treatment time during which the arch wire appliance was in position.

Fig. 13. Case 2. Seventh month of treatment. Intraoral photographs showing that the lingual bracket on the teeth other than the first molars has already been removed and that the space for eruption of the canines is being secured by means of a lingual arch wire, with use being made of the lingual bracket on the first molars.

Case 2

Patient K. K., a 12-year-old girl with an overjet of 0 mm. and an overbite of -0.5 mm., had a Class I malocclusion (Fig. 11). The same records were taken as in Case I, and both the family history and the patient’s growth were found to be normal. The anterior teeth showed a near edge-to-edge condition, and the maxillary canines were just erupting. The mesiodistal widths of ali teeth were 1 S.D. larger than the average mesiodistal tooth size for Japanese females, The cephalometric evaluation was near normal (ANB = 5 degrees, FMA = 33 degrees. FMIA = 57 degrees, IMPA = 90 degrees, Y axis = 67 degrees, gonial angle = 126 degrees, esthetic line: upper lip = -2.5 mm. and lower lip = -3.0 mm.). As a result of analysis of the above data, it was decided that limited treatment should be started on the anterior teeth and then the case should be re-evaluated on the basis of the outcome of the tentative treatment.

The overbite was to be improved by anterior movement and extrusion of the maxillary anterior teeth, and then the space for the eruption of the canines would be secured.

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Fig. 14. Case 2. Cephalometric and panoramic radiographs before treatment (A) and during the eighth month of ireatment (B).

A lingual bracket mushroom arch wire appliance was employed. For labial movement, the appliance has the advantage of a pressing force, as in a palatal expansion appliance.

Bands with a lingual bracket were applied on the first molars, edgewise brackets were placed on the lingua) surface of the anterior teeth, and a lingual bracket was bonded on the first premolars. The treatment objective at the initial stage was achieved in several months; therefore, the brackets on teeth other than molars were removed, immediately followed by use of the lingual arch wire for the purpose of securing the space necessary for eruption of the canines (Figs, 12, 13, and 14)

Fig. 15. Case 3. Pretreatment facial and intraoral photographs of 12-year-old girl.

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Fig. 16. Case 3. Eighteenth month of treatment. Intraoral photographs showing that the maxillary anterior teeth have been expanded anteriorly by means of the edgewise appliance and that the overbite has been improved. (The surface of the teeth were being decalcified in a wide area.)

Case 3

Patient F. S., a 12-year-old girl, had a Class I malocclusion with an anterior cross-bite (Fig. 15). Facial and intraoral photographs, orthodontic study models, and cephalometric, intraoral. and panoramic radiographs were taken. The family history revealed that the patient’s older sister had been treated for a malocclusion with symptoms identical to the patient’s, The patient’s nutrition and growth conditions were good. The anterior teeth showed an overjet of -3.5 mm. and an overbite of 8 mm. The discrepancy in arch length was 9 mm. in the maxilla and 1 mm. in the mandible. Many teeth were carious, and the teeth seemed to be rather fragile. Cephalometric evaluation revealed a mild tipping of the anterior mandibular teeth and excessive lingual tipping of the maxillary anterior teeth (ANB = 0 degrees, FMA = 27 degrees, FMIA = 63 degrees, IMPA = 90 degrees, Y axis = 60 degrees, gonial angle = 124 degrees, interincisal angle = 145 degrees, esthetic line: upper lip = 2.5 mm. and lower lip = -2.0 mm.). As a result of the analysis, this case was diagnosed as one in which the problem was centered in the maxilla and in the maxillary anterior teeth.

Am. :. Orrhou Dwrmber 1979

Fig. 17. Case 3, Twenty-seventh month of treatment. intraoral photographs showing 3vercorrection of the central line and lateral teeth.

It was decided that the occlusion should be improved by anterior expansion of the maxillary anterior teeth. An edgewise appliance was employed first but, during the course of treatment, that appliance was replaced by the lingual bracket mushroom arch wire appliance because of decaIcifica- tion on the labial surfaces of the teeth. Overcorrection of the occlusion at the median line and posterior teeth was achieved (Figs. 16 to 19). In this case, decalcification of the teeth could be !essened by use of the labial treatment appliance first, followed by the lingual treatment appliance. The treatment appliances were used consecutively for 27 months.

iscussion

The patients treated with the lingual bracket mushroom arch wire appliance in an effort to approach orthodontic treatment from the standpoint of esthetics were satisfied with the procedure. More concretely, in spite of their complaints about discomfort to the tongue and some disturbances in pronunciation while they wore the appliance, none of the patients wanted to be switched over to the conventional labial and huccal appliance or to have the original appliance removed. These adverse effects to the tongue and pronuncia-

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Fig. 18. Case 3. Posttreatment facial and intraoral photographs of patient at 14 years of age.

Fig. 19. Case 3. Cephalometric and panoramic radiographs before (A) and after (B) treatment

tion are important points to be studied further. Although the appliance had no great effect on the pronunciation of vowels, there were some patients in clinical practice whose pronunciation of “s, t, r, and 1” was affected. This point is still under investigation, but the analysis of consonants is very difficult.

Patients consider this lingual technique to be more esthetic since people are unaware that they are under orthodontic treatment. It is advantageous because the lips are less prone to injury and there is no feeling of extrusion of the lips. Another advantage to the orthodontist is high patient acceptance for lengthy treatment.

Chairtime is long, however, and there is discomfort since the patients must keep their

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mouths open during this time. There is irritation to the tongue, and it is difficult for patients to pronounce certain words until they become accustomed to the appliance. Brushing teeth is also difficult. A disadvantage to the orthodontist is that the teeth tend to be tipped mesiodistally, making treatment difficult. This technique also requires that the patient and the orthodontist assume an unnatural posture for a long time. Since treatment with a J-hook appliance is impossible from the lingual side, it is difficult to improve a deep overbite.

These are the advantages and disadvantages which I have noticed in practical treat- ment. Some of the disadvantages may be overcome through modification of attachments and use of auxiliaries along with indirect bonding. It is hoped that the concept will encourage a larger segment of the population to seek the benefits of orthodontic treatment.

REFERENCES 1. Fujita, Kinya: Development of lingual-bracket technique, (esthetic and hygienic approach to orthodontic

treatment), J. Jpn. Sot. Dent. Apparatus Materials 19:81-94, 1978. 2. Fujita, Kinya: Development of lingual-bracket technique, J. Jpn. Orthod. Sot. 37:381-384, 1978. 3. Matsui, Mieko: Fujita, Kinya, and Mochizuki, Kayoko: Brushing method for the lingual-bracket technique

with Fujita, J. Jpn. Orthod. Sot. 37:399-403, 1978,

3-9-16 Shonai, Niihama, Ehime 792, Japan