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regions having normal or near-normal hearing sensitivity rather

Madell et al., Pediatric Audiology: Diagnosis, Technology, and Management, 3rd Ed. (ISBN 978-1-62623-401-7), copyright © 2019 Thieme Medical Publishers. All rights reserved. Usage subject to terms and conditions of license.

than routing these frequency regions through the ampliﬁcation

pathway.

As with earmolds, the choice of hearing aids for older children

should be appropriate for the 5-year age range over which they

will be used. Once adolescents or teenagers reach the age when they and their peers are routinely given responsibility for devices such as cellular phones and automobiles, they are then likely to be responsible for smaller ear-level aids or custom in-the-ear or in-the-canal devices, if their hearing losses and listening needs permit (and if RM is not needed). Receiver-in-the-canal devices may be ideal for this age group because they are small, cosmetically appealing (because of the thin wire), but large enough to accommodate technological features such as Bluetooth, telecoil, and direct audio input. Because retention in the ear can also be an issue in active adolescents, receiver-in-the-canal devices are best coupled to the ear with a custom earmold. These earmolds also optimize the sound quality in the ear canal. Contrary to receiver-in-the-canal devices, thin-tube coupling to the earmolds does not share the same advantages. Such instruments are more

susceptible to signiﬁcant high-frequency attenuation, as seen in

Fig. 20.3 for an 11-year-old with moderate hearing levels. This girl had been using her thin-tube hearing aids for a number of years before this evaluation, such that she did not spontaneously pro-

duce the voiceless /s/ phoneme in her speech. Real-ear veriﬁcation at the time of her hearing aid ﬁtting and at regular follow-up visits

might have prevented years of unnecessary high-frequency loss. Finally, although an adolescent may wish to transition to a smaller

device, it is not appropriate to sacriﬁce power and audibility for

size in cases of severe hearing loss.

20.2.3 Selectable Amplication Features

As children reach the age when they are able to skillfully use the controls on digital devices such as cellular phones, remote

controls, and gaming devices (about age 7), the selectable ampliﬁcation features provided by the hearing aids should be

enabled. The most important of these is the volume control. Some concern has been raised regarding adolescents’ ability to select a volume control setting that provides optimal audibility, which may detract from their ability to perceive speech in some listening environments. However, in the absence of an adjustable volume control, adolescents have few options for managing the high-level noise that occurs pervasively in preschool through high school settings. In fact, Crukley et al30 found that noise

levels in the classroom rarely fall below 50 dBA, while levels in

the hallway, cafeteria, gymnasium, and other locations within school are 90 dBA on average. Put simply, children contend with background noise throughout the day and whenever they wish to communicate with someone at school.

Pitfall

Children must contend with moderate to high levels of noise whenever they wish to communicate with someone at school.

20 Hearing Aids for Infants, Children, and Adolescents

Fig. 20.3 Right- and left-ear real-ear measures of behind-the-ear thin-tube hearing aids worn by an 11-year-old with moderate hearing loss.

There are known eects of noise on children’s health and

well-being, from which children who wear hearing aids are not immune. Long-term exposure to uncontrolled noise in the environment (e.g., living for years in a noisy neighborhood) can have

trimental eects on children’s performance and motivation

for tasks involving reading, math, memory, and attention. Several studies have shown that normally-hearing children

exposed to chronic aircraft noise (95 dBA) were less motivated

to complete complex tasks and were more likely to relinquish decision-making power to others. attributed to a sense of learned helplessness in which children feel they have little or no control over their environment, a perception that undermines their motivation to succeed.37 Children are also annoyed by poor acoustic environments that include irrelevant background noises.38 That is, children’s poor response to noise is thought to be related more strongly to annoyance at extraneous sounds than to the level of the noise itself.39 In the absence of an adjustable volume control, children may concede their lack of control or, worse, remove the hearing aids altogether. Enabling the volume control during the early grade school years provides children the opportunity to exert some control over their listening environments.

In addition to a volume control, older children and adolescents

may beneﬁt from noise management. Children as young as 8 years have been shown to select the most eective noise management

feature from among combinations of directional microphone and digital noise reduction technologies to optimize their speech perception in noise and babble.40 More importantly, children’s choice of noise management features suggests that they prefer features that provide listening comfort but not at the expense of speech perception. Thus, they are able to make good choices with their hearing aid technology.

When programming hearing aids with noise management features, it is recommended that they be enabled in dedicated memories so that the child can choose when to use these features. If a noise management feature such as directional microphone technology is set to work continuously or in an automatic fashion, children may not recognize when the hearing aids are attenuating input they would like or need to hear—for example, the responses of other students in the classroom, the friend sitting beside them in the cafeteria, or a parent calling to them from behind. When features are programmed into separate memories, it is important to review the purpose of each memory

34,35,36

This outcome has been

31,32,33

221

III Hearing Access Technologies for Infants and Children

with the child over several appointments and to practice using it

in dierent scenarios. Also, digital noise reduction features function dierently across manufacturers. Electroacoustic measures show that some are more eective than others in steady-state

noise. However, the results of multiple studies consistently show that both children and adults report better listening comfort with noise management features,

41,42

Because speech perception is neither improved nor decreased with the use of digital noise reduction,

42,43

it can be provided in dedicated hearing-aid

memories with conﬁdence that it will oer children an option

in noisy situations other than reducing the volume or removing their hearing aids.

20.3 Things That Will Change and

Things That Won’t

Because hearing aid technology changes rapidly over time, the technology used by children today will evolve and be replaced with more advanced technology in a few short years. For example, Bluetooth connectivity currently enables users to link their hearing aids wirelessly to personal digital devices (e.g., cellular phone, computer, tablet), a feature that was introduced recently and that may be replaced by a new form of connectively just as quickly. Likewise, signal processing strategies that optimize the

ampliﬁcation bandwidth and listening in noise will continue to

evolve, requiring careful attention to appropriate real-ear and

behavioral measures to determine beneﬁt.

Despite the rapid changes in hearing aid technology that

will inevitably occur, several fundamental principles of ﬁtting

hearing aids to infants, children, and adolescents will remain for the foreseeable future. Objective measures of hearing aid output

in the ear canal will continue to be needed when ﬁtting hearing

aids to infants and young children. As children mature, they will

need to be included in the ﬁtting process to select hearing aid

features as their communication environments and listening needs change. Children in educational settings will continue to need noise management features for listening comfort and to promote consistent hearing aid use as well as the ability to connect to a RM system. Finally, knowledgeable and caring professionals will always be needed to guide pediatric patients through the turbulent adolescent years as they reconcile their need to hear with their personal feelings about their hearing and hearing aid use.

Discussion Questions

1. What information would you provide about hearing aid

options and tting to the parents of a 6-month-old baby recently identied with a moderate, bilateral hearing loss?

2. What information would you provide about hearing aid

options and tting to the parents of a 10-year-old child who

has worn hearing aids since birth?

3. What information would you provide about hearing aid

options and tting to a 17-year-old who acquired hearing

loss at the age of 7, wore hearing aids for a few years before rejecting them at the age of 14, and is now needing them for his part-time job?

References

[1] American Academy of Pediatrics, Joint Committee on Infant Hearing. Year 2007

position statement: principles and guidelines for early hearing detection and intervention programs. Pediatrics 2007;120(4):898–921

[2] American Academy of Audiology. Clinical Practice Guidelines: Pediatric Ampliﬁ-

cation. https://www.audiology.org/sites/default/ﬁles/publications/PediatricAmpliﬁcationGuidelines.pdf. 2013. Accessed December 28, 2017

[3] McCreery RW, Walker EA, Spratford M, et al. Longitudinal predictors of aided

speech audibility in infants and children. Ear Hear 2015;36(Suppl 1):24S–37S

[4] Moeller MP, Tomblin JB; OCHL Collaboration. Epilogue: conclusions and implica-

tions for research and practice. Ear Hear 2015;36(Suppl 1):92S–98S

[5] Tomblin JB, Harrison M, Ambrose SE, Walker EA, Oleson JJ, Moeller MP. Lan-

guage outcomes in young children with mild to severe hearing loss. Ear Hear

2015;36(Suppl 1):76S–91S

[6] Keefe DH, Bulen JC, Arehart KH, Burns EM. Ear-canal impedance and reection

coecient in human infants and adults. J Acoust Soc Am 1993;94(5):2617–2638

[7] Feigin JA, Kopun JG, Stelmachowicz PG, Gorga MP. Probe-tube microphone

measures of ear-canal sound pressure levels in infants and children. Ear Hear

1989;10(4):254–258

[8] Moodie KS, Seewald R, Sinclair ST. Procedure for predicting real-ear hearing aid

performance in young children. Am J Audiol 1994;3(1):23–31

[9] Seewald RC, Moodie KS, Sinclair ST, Scollie SD. Predictive validity of a procedure

for pediatric hearing instrument ﬁtting. Am J Audiol 1999;8(2):143–152

[10] Gustafson S, Pittman A, Fanning R. Eects of tubing length and coupling method

on hearing threshold and real-ear to coupler dierence measures. Am J Audiol 2013;22(1):190–199

[11] Bagatto MP, Scollie SC. Current approaches to the ﬁtting of ampliﬁcation to

infants and young children. In: Tharpe AM, Seewald R, eds. Comprehensive

Handbook of Pediatric Audiology. 2nd ed. Plural Publishing; 2016:631–658

[12] Tharpe AM, Sladen D, Huta HM, McKinley Rothpletz A. Practical considerations

of real-ear-to-coupler dierence measures in infants. Am J Audiol 2001;10(1):41– 49

[13] Bagatto MP, Scollie SD, Seewald RC, Moodie KS, Hoover BM. Real-ear-to-coupler

dierence predictions as a function of age for two coupling procedures. J Am Acad Audiol 2002;13(8):407–415

[14] Buttazzoni E, Gregori D, Paoli B, et al; Susy Safe Working Group. Symptoms

associated with button batteries injuries in children: an epidemiological review.

Int J Pediatr Otorhinolaryngol 2015;79(12):2200–2207

[15] Pittman AL, Pederson AJ, Rash MA. Eects of fast, slow, and adaptive amplitude

compression on children’s and adults’ perception of meaningful acoustic information. J Am Acad Audiol 2014;25(9):834–847

[16] Ricketts TA, Tharpe AM. Potential for directivity-based beneﬁt in actual class-

room environments. In: Seewald R, Bamford J, eds. A Sound Foundation Through

Early Ampliﬁcation 2004: Proceedings of the Third International Conference. Bungay, Suolk, UK: Immediate Proceedings Ltd; 2004:143–153. http://www.

phonak.com/content/dam/phonak/b2b/Events/conference_proceedings/

adult_conference_chicago_2004/friday/proceedings_chicago04_10.pdf. Accessed December 28, 2017

[17] Scollie S, Seewald R, Cornelisse L, et al. The Desired Sensation Level multistage

input/output algorithm. Trends Amplif 2005;9(4):159–197

[18] Keidser G, Dillon H, Flax M, Ching T, Brewer S. The NAL-NL2 prescription proce-

dure. Audiology Res 2011;1(1):e24

[19] Clarke BR, Horvath A. Children who wear individual hearing aids in British

Columbia, Canada. Scand Audiol 1979;8(3):131–136

[20] Hadjikakou K, Petridou L, Stylianou C. Evaluation of the support services provid-

ed to deaf children attending secondary general schools in Cyprus. J Deaf Stud

Deaf Educ 2005;10(2):203–211

[21] Kiese-Himmel C, Ohlwein S, Kruse E. Acceptance of wearing hearing aids by

children: a longitudinal analysis [in German]. HNO 2000;48(10):758–764

[22] Markides A. The use of individual hearing aids by hearing-impaired children: a

long-term survey, 1977-1987. Br J Audiol 1989;23(2):123–132

[23] Marttila TI, Karikoski JO. Hearing aid use in Finnish children—impact of hearing

loss variables and detection delay. Int J Pediatr Otorhinolaryngol 2006;70(3):475–

480

[24] Seifert E, Rose S, Hahn M, et al. Status of hearing aid use by children in schools

for the hearing impaired and deaf [in German]. HNO 2001;49(5):382–387

[25] Hintermair M. Parental resources, parental stress, and socioemotional develop-

ment of deaf and hard of hearing children. J Deaf Stud Deaf Educ 2006;11(4):493– 513

[26] Hintermair M. Prevalence of socioemotional problems in deaf and hard of hear-

ing children in Germany. Am Ann Deaf 2007;152(3):320–330

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[27] Punch R, Creed PA, Hyde MB. Career barriers perceived by hard-of-hearing

adolescents: implications for practice from a mixed-methods study. J Deaf Stud

Deaf Educ 2006;11(2):224–237

[28] Elkayam J, English K. Counseling adolescents with hearing loss with the

use of self-assessment/signiﬁcant other questionnaires. J Am Acad Audiol

2003;14(9):485–499

[29] Pittman AL. Short-term word-learning rate in children with normal hearing and

children with hearing loss in limited and extended high-frequency bandwidths. J

Speech Lang Hear Res 2008;51(3):785–797

[30] Crukley J, Scollie S, Parsa V. An exploration of non-quiet listening at school.

Journal of Educational Audiology 2011;17:23–35

[31] Evans GW, Lepore SJ. Nonauditory eects of noise on children: a critical review.

Childrens Environments. 1993;10(1):31–51

[32] Shield BM, Dockrell JE. The eects of environmental and classroom noise

on the academic attainments of primary school children. J Acoust Soc Am

2008;123(1):133–144

[33] Shield BM, Dockrell JE. The eects of noise on children at school: a review. Build

Acoust 2003;10(2):97–116

[34] Cohen S, Evans GW, Stokols D, Krantz DS. Behavior, Health, and Environmental

Stress. New York, NY: Plenum; 1986

[35] Cohen S, Krantz DS, Evans GW, Stokols D, Kelly S. Aircraft noise and children:

longitudinal and cross-sectional evidence on adaptation to noise and the eectiveness of noise abatement. J Pers Soc Psychol 1981;40(2):331–345

[36] Cohen S, Evans GW, Krantz DS, Stokols D. Physiological, motivational, and cogni-

tive eects of aircraft noise on children: moving from the laboratory to the ﬁeld. Am Psychol 1980;35(3):231–243

[37] Abramson LY, Seligman ME, Teasdale JD. Learned helplessness in humans:

critique and reformulation. J Abnorm Psychol 1978;87(1):49–74

[38] Dockrell JE, Shield B. Children’s perceptions of their acoustic environment at

school and at home. J Acoust Soc Am 2004;115(6):2964–2973

[39] Lundquist P, Holmberg K, Landström U. Annoyance and eects on work from

environmental noise at school. Noise Health 2000;2(8):39–46

[40] Pittman AL, Hiipakka MM. Hearing impaired children’s preference for, and per-

formance with, four combinations of directional microphone and digital noise r

eduction technology. J Am Acad Audiol 2013;24(9):832–844

[41] Mueller HG, Weber J, Hornsby BW. The eects of digital noise reduction on the

acceptance of background noise. Trends Amplif 2006;10(2):83–93

[42] Ricketts TA, Hornsby BW. Sound quality measures for speech in noise through a

commercial hearing aid implementing digital noise reduction. J Am Acad Audiol

2005;16(5):270–277

[43] Pittman A. Children’s performance in complex listening conditions: ef-

fects of hearing loss and digital noise reduction. J Speech Lang Hear Res 2011;54(4):1224–1239

223

21 Osseointegrated Implants for Children

Lisa Vaughan Christensen

Summary

The osseointegrated implant is an implantable percutaneous or transcutaneous bone conduction hearing device that has been proven a viable and successful device when used with children.

This system is typically implanted around 5 years of age. For use in children under 5 years of age, the sound processor may be

used on a softband. This device is used most typically for patients with conductive and mixed hearing losses in whom traditional hearing aids are not a viable option due to atresia, microtia, or other middle or outer ear abnormalities. It is also often used for patients with single-sided deafness in lieu of contralateral routing of signal hearing aids.

Keywords

osseointegrated, percutaneous, transcutaneous, softband, Baha, Ponto, abutment, single-sided deafness, conductive hearing loss, mixed hearing loss

Key Points

The use of softbands can begin as soon as hearing loss is

•

con rmed, even in young infants.

Osseointegrated implants are a viable option for children

•

with bilateral conductive or mixed hearing losses. Osseointegrated implants are FDA-approved for implantation

•

in children 5 years of age and older. Previously, osseointegrated devices were used primarily for

•

the treatment of atresia associated with Treacher Collins syndrome. Now it is known that many other special populations

bene t as well from this technology.

Implantation must be carefully discussed with families pre-

•

operatively; as with any surgical procedure, there are special considerations and potential complications that should be discussed.

The original term for these devices was “bone-anchored

hearing aids,” but the resulting acronym, BAHA, was treated as

a trademark from the outset.3 Shortly after Cochlear Americas (Centennial, CO) purchased the rights to the BAHA system from

Entiﬁ c Medical Systems (Gothenburg, Sweden) in 2005, the capitalization was dropped, and “Baha” became a pure registered

trademark of Cochlear Americas. When the FDA cleared another bone-anchored device, the Ponto (Oticon Medical, Askim,

Sweden), in 2008, more generic nomenclature for all such devices

became necessary. Terms for this type of implantable device

include “osseointegrated implants,” “bone conduction hearing devices,” and “bone-anchored implants.” For the purposes of this chapter, the term “osseointegrated implants” (or “osseo” for

short) will be used.

21.2 Overview

The osseointegrated implant is an implantable percutaneous or transcutaneous bone conduction hearing device that is secured

to the skull by an osseointegrated titanium ﬁ xture. The tradi-

tional percutaneous osseointegrated system consists of three main components: sound processor, abutment (or snap coupling), and implant (Fig . 21.1). The detachable sound processor and abutment are the external components, and the implant is the internal component. The abutment connects percutaneously to the internal component when the latter is implanted in the skull bone behind the ear. Both the abutment and the implant are made of titanium and are compatible with magnetic resonance imaging (MRI) and computed tomography (CT). The transcutaneous system (Fig. 21.2) comprises three main components as well: sound processor, magnetic coupling, and implant. This con-

ﬁ guration omits the percutaneous abutment and replaces it with

a magnetic coupling system. Both osseo processors provide an alternative pathway for sound to reach the brain through bone conduction instead of air conduction. This process exists because

of osseointegration. Osseointegration was ﬁ rst introduced for

21.1 History

Hearing aid components that were surgically a xed to bone and transmitted sound through that bone to the cochlea were ﬁ rst

introduced as a viable surgical option for bilateral conductive

hearing loss (CHL) or mixed hearing loss (MHL) in 1977.1 These devices were ﬁ rst made commercially available in 19872 in Gothenburg, Sweden, and the ﬁ rst patients were implanted in Nijmengen, Sweden, in June 1988. However, it would be 1996

before the Food and Drug Administration (FDA) approved these devices for use in the United States,3 initially for bilateral CHL or MHL. Other approvals from the FDA would soon follow, with

pediatric approval for implantation in children 5 years of age or

older in 1999,4 bilateral implantation in 2001,5 and implantation for unilateral or single-sided deafness (SSD) in 2002.

Fi g . 21.1 Parts of an osseointegrated implant. (Used with permission from Oticon Medical.)

225

III Hearing Access Technologies for Infants and Children

Fig. 21.2 Anatomic view of transcutaneous implant with abutment and processor. (Used with permission from Cochlear Americas.)

the concept of direct bone conduction with hearing aids by Tjellström et al. highly compatible with osteocytes, which integrate with the surface of the titanium to form a stable connection. This, in turn, creates long-term stability and an ability to withstand load and stress from various directions.

7,8

The titanium oxide surface on the implant is

21.3 Candidacy

with Treacher Collins syndrome, many other cases of CHL and MHL in children can be treated with these devices. Another

special population documented with beneﬁt from osseo devices

are children with Down syndrome. McDermott et al9 found osseo devices to be successful with Down syndrome, with consistent use

for 15 patients who had inconsistent use of traditional hearing

aids and repeated ventilation tubes. Other common indications for osseo devices include but are not limited to chronic otitis media that cannot be medically resolved, hearing loss following cholesteatoma removal, chronic middle ear dysfunction, and middle ear disease.

Any patient with CHL or MHL that is inoperable who does not

beneﬁt from a traditional hearing aid may be a potential osseo

device candidate. A critical factor to consider when determining candidacy for an osseo device is family choice. Even if the CHL or MHL is operable, a family may decide that an osseo device is the best option for their child. Surgical intervention to repair the pinna cosmetically and restore hearing results in mixed outcomes in respect

to multiple operations, cost eectiveness, surgical diculty, poor

audiologic outcomes, and surgical complications. is especially true in syndromic patients where the middle ear is grossly malformed. The use of an osseo implant often results in less surgical intervention with better hearing results compared to surgical correction of aural atresia.15 Therefore, the audiologist and surgeon should present all potential treatments for CHL and MHL as well as evidence-based advantages, disadvantages, and potential complications to the family.

10,11,12,13,14

This

The FDA, beginning in 1995, outline use of an osseo implant as a

device to be used by patients who have CHL or MHL and who can still beneﬁt from sound ampliﬁcation (Table 21.1).3 For MHL, the pure tone average (PTA) for bone conduction thresholds should

be less than or equal to 45 dB hearing loss (HL). In 1999, the FDA cleared usage of the osseointegrated systems in children 5 years

of age and older. The lower the bone conduction thresholds, the closer the aided thresholds will be to the normal range.4 The

ability to give the proper amount of ampliﬁcation is critical when

working with children in the process of acquiring speech and language skills. Manufacturers of some osseo processors now

oer “power” and/or “super power” devices, enabling patients with greater degrees of bone conduction loss (up to 45 dB HL) to be ﬁtted properly.

Although the most common use of osseo implants in children

has been for treatment of ear canal atresia, especially in children

Table 21.1 Osseo implant candidacy criteria

Type Criteria Softband

Bilateral Implants

SSD Implants

Abbreviations: CHL, conductive hearing loss; MHL, mixed hearing loss; PTA, pure tone average; SSD, single-sided deafness

Bilateral CHL

•

Bilateral MHL (bone conduction PTA of 45 dB or less or equal to 60% speech discrimination scores)

•

SSD or unilateral CHL recommended only after 1 year of age when proper verication and placement can be achieved

•

Symmetric bone conduction thresholds less than 10 dB dierence on average (0.5, 1, 2, and 3 kHz) or less than 15 dB at

•

individual frequencies 5 years of age or older

•

Profound unilateral hearing loss

•

MHL or CHL with a PTA greater than 50 dB

•

Better-hearing ear must be normal (15 dB or less in children)

•

5 years of age or older

•

Pearl

Perhaps the most unique aspect of osseo systems is the ability to conduct preoperative test measures that simulate postoperative results.

21.3.1 Preoperative Testing

Perhaps the most unique aspect of osseo systems is the ability to conduct preoperative test measures that simulate postoperative results. There are three ways to conduct testing preoperatively. First, the sound processor can be connected to a small plastic

226

coupler, known as the test rod, which is held tightly to the mas-

toid or between the teeth. Through bone conduction, the patient will be able to hear through the sound processor. When working with children, the test rod is best used as a listening check tool for audiologists, teachers, parents, or other professionals who may need to conduct a daily listening check for the child. To use as a listening check device, simply plug both ears with your

ﬁngers or earplugs and place the test rod, with the processor

in place, on either the mastoid or the jaw/tragus area. This will allow listening through the osseo processor to determine sound quality, similar to performing listening checks on traditional

ampliﬁcation.

The other preoperative testing apparatus is the testband, which consists of a metal headband in which the processor can be connected. The testband enables the patient to try the processor in

dierent listening environments. Because the testband is made of

metal, long periods of wear time may provide some discomfort. For longer periods of wear time, especially during extended trial periods, the use of a softband is often recommended (Fig. 21.3). The softband is an adjustable band that contains a snap coupler and enables the sound processor to be snapped in place for preoperative testing, trial periods, and for young children to wear before they are old enough for surgery.

Preoperative testing protocols dier with the age of the patient

and the indication for the osseo device. For children with bilateral

CHL or MHL, behavioral testing can be completed in soundﬁeld

using age-appropriate audiometry, with and without a softband (or testband). It is important to note that the sound quality of the testband and softband is slightly reduced compared to the osseointegrated implant, especially at higher frequencies, where attenuation through skin is greatest.

16,17,18,19

21.4 Counseling and Procedures

21.4.1 Preoperative Expectations

As with any implantable device or traditional ampliﬁcation, it is

important to give the family and child a realistic expectations for the osseo system. The child and family should be well informed and have the proper expectations prior to implantation. The poorer the bone conduction thresholds, the greater the chance that aided thresholds will be suboptimal. In this situation, it is particularly important to complete aided behavioral testing utilizing the testband or softband, which enables the audiologist to assess audibility and to predict access to speech and language.

Pitfall

Because of the percutaneous nature of the traditional osseo implant, it is important that a family member, guardian, or the child be able to care for the abutment and the skin around it. This health care should be discussed at length with the family prior to implantation. Otherwise, complications can result, such as infection, skin overgrowth, or extrusion of the abutment or implant.

21 Osseointegrated Implants for Children

Fig. 21.3 Softband. (Used with permission from Oticon Medical.)

ilization of the transcutaneous osseo system should prevent the complications associated with the previous percutaneous coupling. At present, however, limited data have been produced to reinforce this thought, and transcutaneous systems provide somewhat less gain then percutaneous systems.

Also of importance when implanting children with congenital

malformations is sucient bone volume and bone quality—a

necessary condition for successful implantation and proper osseointegration. Extreme sensory sensitivities and developmental

delays that would aect the ability to properly clean and maintain

the site daily should also be considered. In addition, developmen-

tal delays that prevent ecient head control or balance/stability

for walking and potential falls should also be considered prior to implantation. These conditions can pose potential problems for implant extrusion or the ability to keep the sound processor snapped on the abutment consistently.

21.4.2 Surgical Procedures

Osseo implants can be surgically implanted utilizing either a one-stage or a two-stage surgical procedure. Exact procedures will vary from surgeon to surgeon. In a one-stage procedure, the placement of the implant and typically premounted abutment are completed in one operation. During the same operation, soft tissue and hair follicles are removed around the abutment. This is typically done as an outpatient procedure.

During the ﬁrst stage of a two-stage surgical procedure, the

implant is placed, and a cover screw is put over the implant. The implant is left to osseointegrate with the bone before the abutment is attached. The time for osseointegration varies but is typically

227

III Hearing Access Technologies for Infants and Children

3 to 6 months. After osseointegration has occurred, the second

stage of the surgery is conducted, in which the abutment is placed. Tissue and hair follicle reduction may be done in either stage but

are most commonly completed during the ﬁrst stage of the surgery.

Therefore, only a skin biopsy punch is needed to expose the implant at the second stage instead of another full surgical incision.

One-stage procedures are typically reserved for adults with good bone quality as assessed by the surgeon. Two-stage procedures are typically considered for pediatric cases, individuals with poor bone quality, or irradiated patients. Often during pediatric

surgical procedures, a “sleeper” or “rescue” implant is used. The

sleeper implant is simply an additional implant placed in the bone that does not undergo the second-stage operation in which the abutment is attached. It is simply there as a backup should the initial implant become harmed in any way, allowing a second abutment to be placed on the sleeper implant as soon as possible without waiting for an additional osseointegration period if an implant fails or is damaged.

21.4.3 Postoperative Appointments

Sound processor ﬁtting dates are determined by the surgeon and

are typically based on single- or two-stage surgery, osseointegration, and the healing processes of the patient for percutaneous implants. Typically, one-stage procedures have sound processor

ﬁttings between 3 and 6 months after the surgery. Patients undergoing two-stage procedures are typically ﬁtted with the sound processor between 2 and 6 weeks after the second operation.

Advances in surgical techniques and hardware have reduced the amount of time between surgery and activation in several other countries. This is likely to be applicable in the United States in the future. For transcutaneous implants, the current FDA guideline

calls for a 4-week delay between surgery and activation.

During the sound processor ﬁttings, the following topics

should be discussed and demonstrated for the child and family: (1) daily cleaning of the abutment for percutaneous implants, using the soft brush provided by the manufacturer plus a mild soap and water; (2) proper removal and replacement of the sound

processor; (3) battery information; (4) magnet strength and use of comfort pads for transcutaneous implants; and (5) operation

of the sound processor. Also at this time, the audiologist should perform aided behavioral testing (Table 21.2). There are a variety of pediatric-friendly options for programming and preparing the sound processors, such as lockable battery doors, lockable volume controls, the ability to add remote microphone (RM) systems, and retention clips that help prevent the sound processors from being lost or dropped and damaged. Also available are direct audio input cords that can be used for MP3 players or computers and RMs (Fig. 21.4). Subsequent appointments should include audiologic testing for changes in hearing (especially bone conduction), aided behavioral testing to ensure the osseo system is functioning properly, and abutment checks for cleanliness and stability. The condition of the skin around the abutment should be checked

by the surgeon or audiologist every 3 months for the ﬁrst year with children. Subsequent appointments after the ﬁrst year can generally be reduced to every 6 months for the following year and,

eventually, yearly appointments with the audiologist and surgeon.

21.5 Softband

When children are born with a CHL or MHL, they may be candidates for an osseo implant. Current FDA regulations recommend

implantation of the device at or after 5 years of age,4 but o-label implantation under 5 years of age is becoming more common in

the United States. In several other countries, implantation under

5 years is routine. For children under the age of 5, the use of a

softband has been demonstrated to deliver results that approximate those of implantation.

soon as the hearing loss is conﬁrmed, in the same manner as with traditional ampliﬁcation. The softband is a transcutaneous

(across the skin) application of the osseo implant. It consists of an adjustable band and a snap coupler that holds the sound processor to the band and holds the snap coupler to the skin. Previous softbands consisted of an elastic band with a Velcro fastener; however, both manufacturers have changed to a latexfree and Velcro-free softband to prevent the allergic reactions and skin irritations that were sometimes seen with the previous versions (Fig. 21.3). Today’s softbands also include a safety release feature that is designed to release if the softband is ever caught or snagged so that the child is not in danger of being harmed. Also available is an option that enables wearing two

sound processors on one softband for a bilateral ﬁt. There are

also a variety of color options to appeal to children and their families.

16,2 0

The softband can be ﬁtted as

Pearl

The softband can be tted as soon as the hearing loss is conrmed in the same manner as traditional amplication.

Fig. 21.4 Remote microphone for use with Cochlear Americas devices. (Used with permission from Cochlear Americas.)

228

21 Osseointegrated Implants for Children

Table 21.2 Suggested testing protocol

Appointment Tasks Preoperative

Appointment

Postoperative/tting

appointment

3-month postoperative appointment

6-month postoperative appointment

9-month postoperative appointment

Maintenance Appointments

(frequency of these appointments should be determined by the audiologist based on the length of time since implant and age of the child)

Abbreviations: CHL, conductive hearing loss; CT, computed tomography; MHL, mixed hearing loss; CT, computed tomography

Full audiologic evaluation to determine candidacy for osseo implant

•

Trial in oce with processor on testband or softband (device may be sent home for extended trial if deemed necessary

•

by the audiologist) Evaluation with processor on testband or softband

•

For bilateral CHL or MHL, complete functional gain testing with processor on softband or testband

◦

For unilateral CHL or MHL, complete functional gain testing with processor on softband or testband and masking in

◦

the better-hearing ear

For SSD, obtain speech-in-noise testing in soundeld and age-appropriate outcome measure to assess daily

◦

listening skills

Surgeon appointment to assess skull thickness (usually by CT scan) and other surgical considerations deemed

•

necessary by the surgeon

Discussion with the family and/or patient on dierences between percutaneous and transcutaneous implants, along

•

with the potential results from both types of implants, depending on the hearing loss of the patient Counseling with patient and family on use of osseo implant to include but not limited to the following:

•

How and when to clean the abutment for percutaneous implants

◦

Magnet strengths and use of comfort pads for transcutaneous implants

◦

Battery size, life, and safety

◦

Removing and replacing processor

◦

Functions of processor

◦

Child-friendly accessories

◦

Full-time wearing of the processor

◦

Determining need for speech/language therapy or educational audiologic needs

◦

Speech-in-noise testing with processor in place

◦

Implant site check to determine skin irregularities or swelling and, for percutaneous devices, abutment tightness

•

check—can be completed by audiologist, surgeon, or nurse; if any irregularities are noted, contact the surgeon Any necessary programming adjustments

•

Speech-in-noise testing

•

Repeat the outcome measures given preoperatively

•

Implant site check to determine skin irregularities or swelling and, for percutaneous devices, abutment tightness

•

check—can be completed by audiologist, surgeon, or nurse; if any irregularities are noted, contact the surgeon Implant site check to determine skin irregularities or swelling and, for percutaneous devices, abutment tightness

•

check—can be completed by audiologist, surgeon, or nurse; if any irregularities are noted, contact the surgeon Any necessary programming adjustments

•

Speech-in-noise testing

•

Repeat the outcome measures given preoperatively

•

Full audiologic evaluation

•

Implant site check to determine skin irregularities or swelling and, for percutaneous devices, abutment tightness

•

check—can be completed by audiologist, surgeon, or nurse; if any irregularities are noted, contact the surgeon Any necessary programming adjustments

•

Speech-in-noise testing

•

Repeat the outcome measures given preoperatively

•

Appointments as requested by the surgeon

•

21.5.1 Softband Ecacy

Hol et al21 studied two children with bilateral congenital aural

atresia ﬁtted with the Baha softband. The results of their study

demonstrated that Baha use with a softband was at least comparable with if not yielding slightly more favorable aided thresholds than conventional bone conduction hearing aids for the two children studied. More recently, Nicholson et al20 found similar

results when studying 25 children aged 6 months of age to 18

years of age. In this study the use of the Baha Softband coupled to the Baha Compact provided a viable treatment for children with

congenital conductive hearing loss, resulting in an average of 40

dB of functional gain across the speech spectrum.

21.5.2 Softband Fitting and Verication

At the present time, bone conduction devices cannot be veriﬁed

electroacoustically in a clinical setting. Children born with aural atresia or microtia are unable to wear air conduction hearing

aids, which are typically veriﬁed clinically using electroacoustic

measures. The American Academy of Audiology (AAA) Pediatric

Ampliﬁcation Guidelines state that aided soundﬁeld thresholds may be useful in veriﬁcation of audibility of the speech spectrum

for bone conduction devices. auditory access is achieved using softbands, behavioral testing must be completed in a soundbooth while the child is wearing the properly functioning processor and softband (functional gain

22[40]

Therefore, to verify that proper

229

III Hearing Access Technologies for Infants and Children

testing). Testing is performed like any other behavioral testing on children, using developmentally appropriate audiologic pro-

tocols. Even for infants and toddlers, soundﬁeld veriﬁcation must be completed when ﬁtting a softband using behavioral obser-

vation audiometry (BOA) or visual reinforcement audiometry (VRA) as appropriate. See Chapters 6 and 7 for more information about behavioral testing in children.

To ensure proper ﬁttings of the softband, families must be counseled on appropriate ﬁtting strategies. The softband should ﬁt tightly enough to make good contact with the skin/skull but

not so tightly that it causes discomfort for the child. If discomfort or redness appears, the audiologist can loosen slightly and retest aided thresholds. If thresholds are still appropriate, the

ﬁt is appropriate.20 Another option, when discomfort or redness

appears while using softbands, is to use the comfort pads designed for the transcutaneous implants. Again, it is important to verify

aided thresholds when modiﬁcations are made to the ﬁtting.

When ﬁtting infants, it is important to remember and note

head control because head movement is limited, and the majority of an infant’s day is spent lying on a portion of his or her head. For infants, it is recommended that the processor on the softband be put more on the temporal or forehead region to ensure the microphone is not covered, to allow more comfort for the infant, and to keep the processor attached to the softband. The retention clip can be used with the softband, clipped to the softband or to the child’s shirt to ensure the processor is not lost. When the infant begins to sit up well and has better head control, it is advised that the softband be moved to the mastoid area. Changing sides of the processor if using a single-processor softband, or repositioning slightly if using a bilateral softband, a couple of times a day can help keep discomfort or irritation to a minimum for these young children.

Because each individual head is dierent in respect to size

and shape, it is important that behavioral testing be conducted to make sure all speech sounds are completely audible for the child. It is important that aided thresholds be as near as possible

to the normal range of hearing for children (15 dB HL) to ensure

the child has access to the entire speech spectrum. Other means

of veriﬁcation should include speech-language assessments and

outcome measures (i.e., parent/teacher questionnaires) for the family to monitor overall progress.

21.6 Implantation

Prior to the development of osseo implants, children and adults with CHL or MHL wore traditional bone conduction hearing aids if surgical intervention and air conduction hearing aids did not yield favorable results. The traditional bone conduction hearing aids were worn throughout the entire lifespan. Now, because of the good results provided by softbands, some surgeons, many audiologists, and most insurance providers ask whether implant

surgery should be considered. Does the potential beneﬁt warrant the risk and monetary dierence between a softband and

implantation?

When looking at aided thresholds of traditional bone conduction hearing aids compared to aided thresholds of the softband, a

statistically signiﬁcant improvement in softband aided thresholds

has been noted.16 The Baha coupled to the abutment has also been

found to be superior to preoperative testbands. noted was that an implanted Baha provided as much gain as a

bone conduction transducer at 500, 1,000, 2,000, and 4,000 Hz.16 These data demonstrate the beneﬁt of osseo systems either on a

softband or implanted. Based on these positive results, an osseo

system should be the ﬁrst choice for intervention rather than the

last option for children with CHL or MHL.

Prior to the FDA ruling on bilateral implantation in 2001, selection of the side of implant was very important.5 Now most osseo implant candidates with symmetrical bilateral CHL or MHL can be implanted bilaterally, and many of these cases are completed with a simultaneous implantation. Symmetrical bone conduction

thresholds are deﬁned by the FDA as less than 10-dB dierence on average at 500, 1,000, 2,000, and 3,000 Hz or less than 15 dB

at individual frequencies (Table 21.1). Some contraindications to bilateral implantation are poor bone density on one side and asymmetrical hearing. Bilateral osseo implants in children were

ﬁrst studied in 2006 by Priwin et al.24 Twenty-two children and

adolescents with either unilateral conductive hearing loss or bilateral conductive hearing loss were studied on their abilities to localize and understand speech in noise. When the children with bilateral conductive losses were given an additional osseo implant, there was improved localization and improved speech recognition

in noise. It is important to note, however, that these ﬁndings were

determined in a laboratory with ideal test conditions.

Also, previously

21.7 Unilateral Hearing Loss/

Single-Sided Deafness

The incidence of profound unilateral sensorineural hearing loss (USNHL), otherwise known as single-sided deafness (SSD),

in children ranges from 0.1 to 3%.

children with profound USNHL tend to perform poorly in school,

display learning diculties, and have behavioral problems

relative to their normal-hearing peers. be attributed to the inability of individuals with SSD to perform well in noise, and they may require some school support; see Chapters 27 and 29 in this text.

Despite evidence that children with unilateral hearing loss

beneﬁt from RM systems and hearing aids, compliance remains

limited in using these devices. either do not work or are not feasible to use outside the classroom even though in the classroom they have been shown to outperform contralateral routing of signals (CROS),35 and personal RMs are costly (e.g., multiple transmitters) or cumbersome (e.g., passaround microphones) when there are multiple talkers or during

group activities. The use of CROS ampliﬁcation for unilateral

hearing loss in children is not recommended, limited data examining this type of technology for children. Thus, treatment options for profound unilateral hearing loss in children are limited, thereby creating a source of frustration and a need for alternative treatments.

In terms of research on osseo integrated systems, two results for 23 children with profound sensorineural hearing loss in one ear and normal hearing in the other (i.e., SSD) with an average

age of 12.6 years demonstrated signiﬁcant improvements on the

Hearing in Noise Test (HINT)37 and the Children’s Home Inventory

of Listening Diculties (CHILD)

25,26

Evidence suggests that

27,28,29

These problems can

30,31,32

33,34

Soundﬁeld FM/infared systems

22,36

and there are

38,39

when wearing the systems.

230

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