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Pediatric Dental Journal

journal homepage: www.elsevier .com/locate /pdj

Case Report

Traction of the lower second premolar byapplication of band-loop space maintainer in anautistic child

Tomonori Hoshino a,*, Kan Saito a,b, Taku Fujiwara a

aDepartment of Pediatric Dentistry, Nagasaki University Graduate School of Biomedical Sciences, 1-7-1 Sakamoto,

Nagasaki 852-8588, JapanbDivision of Pediatric Dentistry, Department of Oral Health and Development Sciences, Tohoku University Graduate

School of Dentistry, Sendai 980-8575, Japan

a r t i c l e i n f o

Article history:

Received 6 March 2013

Received in revised form

19 April 2013

Accepted 8 May 2013

Available online 8 November 2013

Keywords:

Eruptional induction

Autism spectrum disorders

Intellectual disability

* Corresponding author. Tel.: þ81 95 819 767E-mail address: thoshino@nagasaki-u.ac.

0917-2394/$ e see front matter Copyright ª 2013 The

http://dx.doi.org/10.1016/j.pdj.2013.05.001

a b s t r a c t

A band-loop space maintainer, with a hook attached at the tip of the loop, was used to

induce eruption of the lower right second premolar that slanted toward the root of the

neighboring permanent first molar in an 11-year-old autistic child with intellectual

disability. The band-loop space maintainer, which was originally not widely used, was

designed to make the second premolar upright by applying traction by using the ortho-

dontic elastic that was set up on a hook. Furthermore, this device was made as small as

possible, because the boy disliked changes in his environment. He was treated for

approximately 1 year by using this space maintainer. This appliance was effective in

promoting eruption and making his second premolar upright. However, the neighboring

permanent first molar was not inclined or impacted by a counteractive force against the

traction force.

Copyright ª 2013 The Japanese Society of Pediatric Dentistry. Published by Elsevier Ltd. All

rights reserved.

1. Introduction individuals compared to the general population, orthodontic

Autistic individuals have impaired intellectual develop-

ment, atypical repetitive behavior, and hypersensitivity, and

they tend to dislike changes in their environment. However,

children with autism exhibit higher caries prevalence, poor

oral hygiene and extensive unmet needs for dental treat-

ment, as compared to non-autistic healthy controls [1].

Therefore, dentists often have to select appropriate dental

treatments for these children with special needs. In addi-

tion, since malocclusion is more prevalent in autistic

4; fax: þ81 95 819 7675.jp (T. Hoshino).Japanese Society of Pediatric De

treatment needs are greater in children with autism [2].

There are many difficulties in performing orthodontic

treatment and occlusal guidance to improve malocclusion

and eruption anomalies in autistic children, because it is not

easy for them to accept and/or handle the treatment skill-

fully. We have previously reported the use of a removable

orthodontic appliance with a NieTi spring to improve the

cross-bite of the upper incisors in an autistic child [3]. That

appliance was designed using a shape-memory NieTi wire

to make it more durable and withstand rough handling.

ntistry. Published by Elsevier Ltd. All rights reserved.

p e d i a t r i c d e n t a l j o u r n a l 2 3 ( 2 0 1 3 ) 9 1e9 492

Thus, with special modifications, orthodontic therapy may

be possible in autistic children.

In the present case, an autistic child who required eruption

by traction for his lower right second premolar was referred to

our clinic. His mother reported that a band-loop space main-

tainer was previously used on his lower left primary second

molar to guide the eruption and keep the space after the

extraction of his lower left primary first molar. This deter-

mined us to apply a band-loop space maintainer to traction of

the second premolar. Originally, a band-loop space main-

tainer was used for space maintenance after unilateral pre-

mature loss of the primary molar, but it did not function as an

activator for guiding tooth eruption. However, its use as a

space regainer has recently been reported [4]. Therefore, we

tested the use of a band-loop space maintainer for traction of

the impacted premolar in the patient.

2. Case report

A Japanese boy with autism had been referred to the Pediatric

Dentistry Clinic of Nagasaki University Hospital for dental

caries when he was 5 years old. He was diagnosed as high

functioning autism. At first, his degree of cooperation to

dental treatment was very low. Although he had mild intel-

lectual developmental disorder (approximately 70 IQ) and

sometimes parroted unmeaning speech, he had a good

memory and was able to converse with others. At first, his

dental caries treatments were performed under general

anesthesia because he was unfamiliar with the procedures. At

that time, his lower left first primary molar was extracted and

a band-loop spacemaintainer was set on his lower left second

primarymolar. After that, his acceptance of dental treatments

improved by using the tell-show-do technique and behavior

modification. In the end of consultation, the instruments and

procedures of the next dental treatment were explained for

him and his mother beforehand. As one of the visual struc-

tured teaching tools, the photographs of those instruments

were given for him to prepare the next treatment if needed.

Until 9 years of age, he could receive low-invasive dental

treatments such as the use of local anesthesia, scaling, cavity

preparation, resin filling, and extraction of a loose primary

tooth. Since then, he was periodically followed-up and thus

remained caries-free. At 11 years 7 months of age, mobility of

his right lower second primary molars was not observed,

although his upper second primary molars appeared likely to

fall out at any time. An Orthopantomograph was taken

because we suspected that the lower second premolars were

congenitally missing. It revealed that his lower right second

premolar was almost horizontally slanted toward the root of

the neighboring permanent first molar (Fig. 1A). At 11 years 11

months of age, his lower right second primary molar was

extracted and bone fenestration was performed to promote

eruption of the second premolar under general anesthesia

after obtaining his parent’s consent. Subsequently, a band-

loop space maintainer was set (Fig. 2B). We observed the

progress of the second premolar for 4 months. However,

exposure from the alveolar bone alone is not sufficient to

make the lower right second premolar erupt and some bone

was regenerated at the site of fenestration. Thus, under local

anesthesia, we removed the bone on the lower right second

premolar again, and exposed it. Next, we attached a button on

his second premolar, and soldered a hook onto the tip of the

loop on the band-loop spacemaintainer (Fig. 2A and C). At this

time, he could accept these treatments due to repetitive visual

explanation. Successively, his lower right second premolar

was made upright by applying traction using orthodontic

ligature wire and elastic (Fig. 2D). The elastic was changed

monthly. After 3 months, the lower right second premolar

started to become upright (Fig. 2E). After 3 more months, the

tooth became almost vertical, and started to erupt from the

gingiva (Fig. 1B and C). At this time, the orthodontic elasticwas

removed, since the direction and eruption of the tooth had

improved. After 4 more months, the band-loop space main-

tainer was removed, since it was thought that his lower right

second premolar could erupt naturally and correctly. After

this treatment, he was followed up at our dental clinic peri-

odically for clinical observation of this tooth and dental care

for the other teeth. Fig. 1D shows his latest oral photographs,

displaying excellent direction and position of his lower right

second premolar. In the report of this case, we obtained the

permission from his parents.

3. Discussion

Impeded eruption or impaction of permanent teeth has been

reported to occur in 5.6e18.8% of the population [5]. When

excluding the third permanent molars, mandibular second

premolars account for 24% of total tooth impactions, second

only to maxillary canines [6]. In addition, the frequency of

unerupted mandibular second premolars in 15-year-old chil-

dren was found to be 9.7% [7]. These reports show a high

prevalence of impaction of themandibular second permanent

premolar. We believe that this may also be true in children

with autism, and that the need of occlusal guidance for

facilitating the eruption of mandibular second premolars

potentially exists in autistic children too. However, in cases

when an autistic child is caries-free and does not have any

visible trouble, as in the present case, problems such as

impaction of the mandibular second permanent premolar

may not be discovered. Thus, we recommend a periodic

orthopantomographic inspection of the teeth, especially in

children with autism.

Some studies have reported management modalities for

lower second premolar impaction [5,8e10]. As a conservative

approach, removal of a deciduous second molar is first per-

formed.When the lower second premolar does not erupt after

clinical observation for several months, fenestration is per-

formed as a second step, and its eruption progress is clinically

observed for several months. If the lower second premolar

does not erupt despite the fenestration, orthodontic traction is

performed, as a third step. Generally, a multi-bracket method

and/or a lingual arch is used for traction of the impacted lower

second premolar. In the case of a child with autism, treat-

ments of the impacted lower second premolar are performed

until the above-mentioned second step, under behavior

modification and/or general anesthesia. However, many

dentists hesitate to perform orthodontic traction of the

impacted lower second premolars in an autistic child because

Fig. 1 e Orthopantomographs before (A), and during the treatment (B), and oral photographs during (C), and after the

treatment (D) involving the application of a band-loop space maintainer.

p e d i a t r i c d e n t a l j o u r n a l 2 3 ( 2 0 1 3 ) 9 1e9 4 93

of bad handling and rejection of the appliance. We have pre-

viously reported the use of a removable orthodontic appliance

with a NieTi spring to improve the cross-bite of the upper

incisors of an autistic child [3]. In that case, a shape-memory

NieTi wire spring was used, as it does not break easily, to

improve the position of the upper incisors. This case shows

that with special modifications, orthodontic treatment is

possible in children with autism. Thus, we set up the current

appliance for occlusal guidance in the present case. In this

case, we set a band-loop space maintainer at his lower left

Fig. 2 e Schema of traction of the secondary premolar by applic

radiographs at the time of wearing the band-loop space mainta

(D), and at 3 months after the initiation of traction (E). In Fig. 2A, t

a solid and broken arrow. The distal counteractive force would

permanent first molar arising from loss of a deciduous second

primary second molar during the first dental treatment. His

mother suggested that he would accept a small appliance

such as a band-loop space maintainer andmight reject a large

appliance such as a lingual arch and/or a multi-bracket

appliance. Moreover, she desired that he receive orthodontic

traction of his impacted right second premolar and told us

that he would not touch the functional parts of the appliance

with his fingers. Thus, we converted the band-loop space

maintainer, which was already accepted by him, into a trac-

tion device, although it was not an active appliance originally.

ation of a band-loop space maintainer (A), and dental

iner (B), after refenestration (C), at the initiation of traction

he direction of traction and counteraction force is shown as

be offset by the mesial inclination tendency of the

molar.

p e d i a t r i c d e n t a l j o u r n a l 2 3 ( 2 0 1 3 ) 9 1e9 494

The hook that was soldered onto the tip of the loop on the

band-loop space maintainer was designed small so that he

could not touch it.

In this case, the direction of counteraction against the

traction force is shown in Fig. 2A. Generally, a lower perma-

nent first molar is medially inclined due to the loss of a lower

deciduous second molar. Therefore, the distal counteractive

force would be offset by this tendency of the permanent first

molar. Although the downward force remained, the lower

permanent first molar was not impacted because of the short

treatment period. Particularly because the formation of the

root of the second premolar seldom progresses, the treatment

period could be short. Thus, it was indicated that the present

application of a band-loop space maintainer would be suffi-

cient for traction of the lower second premolar, despite this

device being smaller than a lingual arch and a multi-bracket

appliance. The present device is preferable particularly in

children with autism because they tend to dislike large

devices.

In the present case, application of this device resulted in

the successful eruption of his second premolar in approxi-

mately 1 year, suggesting that this appliance can be used for

traction of the second premolar in autistic patients.

Conflict of interest

Authors declare no conflict of interest.

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