Complications of Transcutaneous Protheses - A Systematic Review of Publications Over the Past 10 Years

Abstract Introduction Bone conduction implants, responsible for transmitting sound from an external processor to the inner ear, can be divided into active and passive, depending on the vibratory stimulus location. The use of transcutaneous device has increased, given its aesthetic appeal, the complications and limitations of percutaneous devices, and patient's treatment adherence, focusing mainly on efficacy. However, various complications are associated with the use of transcutaneous prosthesis, which can often be serious. Objective To approach the literature on complications involving transcutaneous bone-anchored prostheses through a systematic review of articles published in the past 10 years (2011-2021). Data Synthesis The MEDLINE, EMBASE, Scopus, and Cochrane Library databases were searched. All articles written in English reporting on currently available transcutaneous prosthesis implantation and its complications were selected. Studies on both children and adults were included. The data on complications were extracted, and complications were classified as minor or major and associated to each device used. Thirty-seven articles were included in the study, of which 14 were prospective cohort studies, 22 were retrospective case series, and 1 was a case report. Most studies (18) included both adults and children. Moreover, 901 implantations were performed, of which 552 implanted Baha Attract (Cochlear Ltd., Sydney, Australia), 244 implanted BoneBridge (MED-EL, Innsbruck, Austria), and 105 implanted Sophono (Sophono Inc., Boulder, CO, USA]). Furthermore, 192 adverse events were reported (total complication rate, 21.3%), with 161 minor complications (84.3%) and 31 major complications (16.1%). Conclusion Transcutaneous prosthesis is an audiological alternative with fewer complications than percutaneous prosthesis. However, its indication should be judicious because complications are common, and although most complications are minor, serious infections requiring explantation may develop.

An Implantable Hearing System As Rehabilitation for Hearing Loss Due to Bilateral Aural Atresia: Surgical Technique and Audiological Results.

OBJECTIVE: To demonstrate the surgical technique and audiological results of a middle ear implant for restoring hearing in patients with bilateral aural atresia and microtia with conductive or mixed hearing loss. MATERIALS AND METHODS: In this prospective study, 12 subjects aged 12 years and older presenting with hearing loss and bilateral congenital aural atresia underwent surgical insertion of a middle ear implant. The patients underwent tympanomastoidectomy with a wide opening of the attic and preservation of the roof of the atresic tympanic bone to expose the middle ear and position the floating mass transducer of the implant. RESULTS: There were no intraoperative or postoperative complications. The hearing threshold averages in a free field were 53.5 dB preoperatively and 25.6 dB postoperatively. Monosyllabic word recognition averaged 61% preoperatively and 91.3% postoperatively. The average speech perception in quiet conditions during the hearing in noise test improved from 67.11 dB to 45.99 dB, and the signal-to-noise ratio improved from 5.64 to 1.31. CONCLUSION: The tested system is an excellent option for auditory rehabilitation of conductive hearing loss due to bilateral ear atresia. The surgery is well structured and safe and provides several alternatives to the surgeon, which is valuable in difficult cases.

Are auditory steady-state responses a good tool prior to pediatric cochlear implantation?

INTRODUCTION: ASSR allow frequency-specific evaluation in intensities up to 120dB HL and detection of residual hearing in patients with severe-to-profound hearing loss. AIM: to compare ASSR thresholds and behavioral test results in children with suspected severe-to-profound hearing loss. METHODS: Cross sectional study to compare ASSR and behavioral responses (VRA or audiometry) in 63 pediatric cochlear implant candidates (126 ears) aged between 6 and 72 months. We included children with normal otomicroscopy, absent responses to click-ABR and otoaccoustic emissions. We excluded children with inner ear malformations, auditory neuropathy spectrum disorder or who did not complete VRA or achieve EEG noise<30nV during the ASSR test. Air-conduction ASSR stimuli were continuous sinusoidal tones presented at 0.5, 1, 2 and 4kHz starting at 110dB HL. Behavioral thresholds were acquired with warble tones presented at 0.5, 1, 2 and 4kHz in each ear through insert or head phones at maximum presentation level of 120dB HL. RESULTS: Behavioral thresholds were obtained in 36.7% (185/504) of all frequencies in all subjects, 9% in intensities >110dB HL. Among 504 ASSR measurements, 53 thresholds were obtained (10.5%). Overall 89.5% of the tested frequencies did not show any response at 110dB HL. Most responses were at 500Hz. Mean differences between behavioral and ASSR thresholds varied from 0.09 to 8.94dB. Twenty-seven comparisons of behavioral and ASSR thresholds were obtained: 12 at 0.5kHz, 9 at 1kHz, 5 at 2kHz and 1 at 4kHz. Absent responses were observed in both tests in 38.1% at 0.5kHz, 52.4% at 1kHz, 74.6% at 2kHz and 81.0% at 4kHz. Specificity was>90% at 1, 2 and 4kHz. In ears with no behavioral response at 120dB HL all ASSR thresholds were in the profound hearing loss range, 90% of them were ≥110dB HL. CONCLUSION: Among 63 pediatric CI candidates, absent responses to high-intensity ASSR was the major finding (specificity>90%) predicting behavioral thresholds in the profound hearing loss range. These findings can be helpful to confirm the decision for cochlear implantation.

Remote programming of cochlear implants / Teleprogramação dos sistemas de implante coclear

PURPOSE: To verify the effectiveness of remote programming of cochlear implants by stimulation levels and results in the perception of speech and free-field audiometry tests. METHODS: Twelve patients from both genders, aged between 18 and 59 years, users of internal cochlear implant and speech processor of the same model for at least 12 months, were selected. Both the remote programming (RP) and the live programming (LP) were performed on the same day, measuring the minimum (T) and maximum (C) stimulation levels of five electrodes with the interpolation of the remaining ones. Speech perception tests were applied using 65 dBSPL (recorded open context sentences and monosyllables). The patients were submitted to free-field audiometry at 250-8,000 Hz frequencies. The results for the RP and LP were compared. RESULTS: Differences in mean of the T levels for three electrodes and the C levels for one electrode were found. No difference between the results was obtained in the speech perception tests and audiometric thresholds in the RP and LP. CONCLUSION: The RP is a simple and effective procedure for programming cochlear implant devices and, although there were differences in the stimulation levels of some electrodes, it did not interfere in the speech perception outcomes. .

OBJETIVO: verificar a efetividade da programação remota do implante coclear por meio dos níveis de estimulação e resultados nos testes de percepção de fala e audiometria em campo livre. MÉTODOS: Foram selecionados 12 pacientes de ambos os gêneros, com idade entre 18 e 59 anos, usuários de implante coclear do mesmo modelo de unidade interna e processador de fala por no mínimo 12 meses. As programações remota (PR) e presencial (PP) foram realizadas no mesmo dia, medindo-se os níveis mínimos (níveis T) e máximos (níveis C) de estimulação de cinco eletrodos, com interpolação dos demais. Foram aplicados testes de percepção de fala (frases em contexto aberto e monossílabos - gravação a 65 dBNPS) e audiometria em campo livre nas frequências de 250 a 8.000 Hz. Os resultados foram comparados entre PR e PP. RESULTADOS: Houve diferença na média dos níveis T em três eletrodos e dos níveis C em um eletrodo. Não houve diferença entre os resultados obtidos nos testes de percepção de fala e nos limiares audiométricos na PP e PR. CONCLUSÃO: A realização da programação remota é simples e eficaz para a programação dos dispositivos de implante coclear e, embora tenha mostrado diferenças nos níveis de estimulação, não interferiu no desempenho da percepção de fala. .

Implantable and Semi-Implantable Hearing Aids: A Review of History, Indications, and Surgery

Introduction: The complaints associated with the use of conventional amplifying hearing aids prompted research at several centers worldwide that ultimately led to the development of implantable devices for aural rehabilitation. Objectives: To review the history, indications, and surgical aspects of the implantable middle ear hearing devices. Data Synthesis Implantable hearing aids, such as the Vibrant Soundbridge system (Med-El Corporation, Innsbruck, Austria), the Maxum system (Ototronix LLC, Houston, Texas, United States), the fourth-generation of Carina prosthesis (Otologics LLC, Boulder, Colorado, United States), and the Esteem device (Envoy Medical Corporation - Minnesota, United States), have their own peculiarities on candidacy and surgical procedure. Conclusion: Implantable hearing aids, which are currently in the early stages of development, will unquestionably be the major drivers of advancement in otologic practice in the 21st century, improving the quality of life of an increasingly aged population, which will consequently require increased levels of hearing support...

Remote programming of cochlear implants.

PURPOSE: To verify the effectiveness of remote programming of cochlear implants by stimulation levels and results in the perception of speech and free-field audiometry tests. METHODS: Twelve patients from both genders, aged between 18 and 59 years, users of internal cochlear implant and speech processor of the same model for at least 12 months, were selected. Both the remote programming (RP) and the live programming (LP) were performed on the same day, measuring the minimum (T) and maximum (C) stimulation levels of five electrodes with the interpolation of the remaining ones. Speech perception tests were applied using 65 dBSPL (recorded open context sentences and monosyllables). The patients were submitted to free-field audiometry at 250-8,000 Hz frequencies. The results for the RP and LP were compared. RESULTS: Differences in mean of the T levels for three electrodes and the C levels for one electrode were found. No difference between the results was obtained in the speech perception tests and audiometric thresholds in the RP and LP. CONCLUSION: The RP is a simple and effective procedure for programming cochlear implant devices and, although there were differences in the stimulation levels of some electrodes, it did not interfere in the speech perception outcomes.

Implantable and semi-implantable hearing AIDS: a review of history, indications, and surgery.

Introduction The complaints associated with the use of conventional amplifying hearing aids prompted research at several centers worldwide that ultimately led to the development of implantable devices for aural rehabilitation. Objectives To review the history, indications, and surgical aspects of the implantable middle ear hearing devices. Data Synthesis Implantable hearing aids, such as the Vibrant Soundbridge system (Med-El Corporation, Innsbruck, Austria), the Maxum system (Ototronix LLC, Houston, Texas, United States), the fourth-generation of Carina prosthesis (Otologics LLC, Boulder, Colorado, United States), and the Esteem device (Envoy Medical Corporation - Minnesota, United States), have their own peculiarities on candidacy and surgical procedure. Conclusion Implantable hearing aids, which are currently in the early stages of development, will unquestionably be the major drivers of advancement in otologic practice in the 21st century, improving the quality of life of an increasingly aged population, which will consequently require increased levels of hearing support.

Retrolabyrinthine approach for cochlear nerve preservation in neurofibromatosis type 2 and simultaneous cochlear implantation

Few cases of cochlear implantation (CI) in neurofibromatosis type 2 (NF2) patients had been reported in the literature. The approaches described were translabyrinthine, retrosigmoid or middle cranial fossa. OBJECTIVES: To describe a case of a NF2- deafened-patient who underwent to vestibular schwannoma resection via RLA with cochlear nerve preservation and CI through the round window, at the same surgical time. RESUMED REPORT: A 36-year-old woman with severe bilateral hearing loss due to NF2 was submitted to vestibular schwannoma resection and simultaneous CI. Functional assessment of cochlear nerve was performed by electrical promontory stimulation. Complete tumor removal was accomplishment via RLA with anatomic and functional cochlear and facial nerve preservation. Cochlear electrode array was partially inserted via round window. Sound field hearing threshold improvement was achieved. Mean tonal threshold was 46.2 dB HL. The patient could only detect environmental sounds and human voice but cannot discriminate vowels, words nor do sentences at 2 years of follow-up. CONCLUSION: Cochlear implantation is a feasible auditory restoration option in NF2 when cochlear anatomic and functional nerve preservation is achieved. The RLA is adequate for this purpose and features as an option for hearing preservation in NF2 patients...

Cochlear implantation through the middle fossa: an anatomic study for a novel technique.

CONCLUSION: The technique proposed is simple, reliable, and provides sufficient exposure of the basal portion of the cochlea while avoiding disabling complications. It enables visualization of the cochlear basal turn and the osseous spiral lamina, facilitating the insertion of the cochlear implant array through the scala tympani. OBJECTIVES: To describe a novel approach for exposing the cochlear basal turn for cochlear implantation through the middle cranial fossa. METHODS: Fifty temporal bones were dissected and a cochleostomy was performed via a middle fossa approach on the most superficial part of the cochlear basal turn, using the superior petrosal sinus, the skeletonized petrous apex, the lateral surface of the meatal plane trailed on the petrous apex from its most proximal portion, and the great superficial petrosal nerve as landmarks. The distance between the landmarks and the distance between the cochleostomy and the round window were measured. RESULTS: In all temporal bones, only the top portion of the cochlear basal turn was uncovered. The cochleostomy allowed both the scala tympani and the vestibule to be exposed. A computed tomography scan of the temporal bones was performed to document the electrode insertion from the cochlear basal turn until its apex. The mean ± SD minor and major distances between the cochleostomy and the meatal plane were estimated to be 2.48 ± 0.88 mm and 3.11 ± 0.86 mm, respectively. The mean distance from the cochleostomy to the round window was 8.38 ± 1.96 mm, and that to the superior petrosal sinus was 9.19 ± 1.59 mm. The mean minor and major distances between the cochleostomy and the long axis of the meatal plane from its most proximal portion were estimated to be 6.63 ± 1.38 mm and 8.29 ± 1.43 mm, respectively.

Cochlear implantation through the middle cranial fossa: a novel approach to access the basal turn of the cochlea.

UNLABELLED: The classic approach for cochlear implant surgery includes mastoidectomy and posterior tympanotomy. The middle cranial fossa approach is a proven alternative, but it has been used only sporadically and inconsistently in cochlear implantation. OBJECTIVE: To describe a new approach to expose the basal turn of the cochlea in cochlear implant surgery through the middle cranial fossa. METHOD: Fifty temporal bones were dissected in this anatomic study of the temporal bone. Cochleostomies were performed through the middle cranial fossa approach in the most superficial portion of the basal turn of the cochlea, using the meatal plane and the superior petrous sinus as landmarks. The lateral wall of the internal acoustic canal was dissected after the petrous apex had been drilled and stripped. The dissected wall of the inner acoustic canal was followed longitudinally to the cochleostomy. RESULTS: Only the superficial portion of the basal turn of the cochlea was opened in the fifty temporal bones included in this study. The exposure of the basal turn of the cochlea allowed the visualization of the scala tympani and the scala vestibuli, which enabled the array to be easily inserted through the scala tympani. CONCLUSION: The proposed approach is simple to use and provides sufficient exposure of the basal turn of the cochlea.

Implante coclear via fossa craniana média: uma nova técnica para acesso ao giro basal da cóclea / Cochlear implantation through the middle cranial fossa: a novel approach to access the basal turn of the cochlea

A técnica clássica para o implante coclear é realizada através de mastoidectomia e timpanotomia posterior. A abordagem pela fossa craniana média provou ser uma alternativa valiosa, embora venha sendo usada para o implante coclear apenas esporadicamente e sem normatização. OBJETIVO: Descrever uma nova abordagem para expor o giro basal da cóclea para o implante coclear através da fossa craniana média. MÉTODO: Cinquenta ossos temporais foram dissecados. A cocleostomia foi realizada através de uma abordagem via fossa craniana média, na parte mais superficial do giro basal da cóclea, usando o plano meatal e seio petroso superior como pontos de reparo. A parede lateral do meato acústico interno foi dissecada após o broqueamento e esqueletização do ápice petroso. A parede dissecada do meato acústico interno foi acompanhada longitudinalmente até a cocleostomia. Design: Estudo anatômico de osso temporal. RESULTADOS: Em todos os ossos temporais, apenas a parte superficial do giro basal da cóclea foi aberta. A exposição do giro basal da cóclea permitiu que as escalas timpânica e vestibular fossem visualizadas. Assim, não houve dificuldade na inserção do feixe de eletrodos através da escala timpânica. CONCLUSÃO: A técnica proposta é simples e permite exposição suficiente do giro basal da cóclea.

The classic approach for cochlear implant surgery includes mastoidectomy and posterior tympanotomy. The middle cranial fossa approach is a proven alternative, but it has been used only sporadically and inconsistently in cochlear implantation. OBJECTIVE: To describe a new approach to expose the basal turn of the cochlea in cochlear implant surgery through the middle cranial fossa. METHOD: Fifty temporal bones were dissected in this anatomic study of the temporal bone. Cochleostomies were performed through the middle cranial fossa approach in the most superficial portion of the basal turn of the cochlea, using the meatal plane and the superior petrous sinus as landmarks. The lateral wall of the internal acoustic canal was dissected after the petrous apex had been drilled and stripped. The dissected wall of the inner acoustic canal was followed longitudinally to the cochleostomy. RESULTS: Only the superficial portion of the basal turn of the cochlea was opened in the fifty temporal bones included in this study. The exposure of the basal turn of the cochlea allowed the visualization of the scala tympani and the scala vestibuli, which enabled the array to be easily inserted through the scala tympani. CONCLUSION: The proposed approach is simple to use and provides sufficient exposure of the basal turn of the cochlea.

Cochlear implants and bacterial meningitis: A speech recognition study in paired samples

Introduction: Cochlear implants may guarantee sound perception and the ability to detect speech at a close-to-normal hearing intensity; however, differences have been observed among implantees in terms of performance on discrimination tests and speech recognition. Objective: To identify whether patients with post-meningitis deafness perform similarly to patients with hearing loss due to other causes. Method: A retrospective clinical study involving post-lingual patients who had been using Nucleus-22 or Nucleus-24 cochlear implants for at least 1 year. These patients were matched with respect to age (± 2 years), time since the onset of deafness (± 1 year), and the duration of implant use with implant users who had hearing loss due to other causes. Speech perception was assessed using the Portuguese version of the Latin-American Protocol for the Evaluation of Cochlear Implants. Results: The sample consisted of 52 individuals (26 in each of the 2 groups). The post-meningitic group had a median of 18.5 active electrodes. The group with hearing loss due to other causes had a median of 21, but no significant statistical difference was observed (p = 0.07). The results of closed- and open-set speech recognition tests showed great variability in speech recognition between the studied groups. These differences were more pronounced for the most difficult listening tasks, such as the medial consonant task (in the vowel-consonant-vowel format). Conclusion: Cochlear implant recipients with hearing loss due to bacterial meningitis, who had been using the device for 1 year performed more poorly on closed- and open-set speech recognition tests than did implant recipients with hearing loss due to other causes...

Prelingual deafness: Benefits from cochlear implants versus conventional hearing aids

Introduction: The majority of patients with hearing loss, including those with severe hearing loss, benefits from the use of hearing aids. The cochlear implant is believed to achieve better results in a child with hearing loss in cases where the severity of disability renders hearing aids incapable of providing adequate sound information, as they require sufficient cochlear reserve so that acoustic detention occurs. Objective: To assess if cochlear implants provide more benefit than conventional hearing aids in prelingually deaf patients. Summary of the findings: The study was a systematic review of scientific papers selected by a search of the SciELO, Cochrane, MEDLINE, and LILACS-BIREME databases. Among the 2169 articles found, 12 studies proved relevant to the issue and presented an evidence strength rating of B. No publications rated evidence strength A. Seven of the studies analyzed were prospective cohorts and 5 were cross-sectional studies. Conclusion: Based on several studies, cochlear implants were demonstrated to be the best current alternative for bilateral severe or profound hearing loss, achieving better results in speech perception and development in prelingual children when compared to conventional hearing aids...

Prelingual deafness: Benefits from cochlear implants versus conventional hearing aids.

INTRODUCTION: The majority of patients with hearing loss, including those with severe hearing loss, benefits from the use of hearing aids. The cochlear implant is believed to achieve better results in a child with hearing loss in cases where the severity of disability renders hearing aids incapable of providing adequate sound information, as they require sufficient cochlear reserve so that acoustic detention occurs. OBJECTIVE: To assess if cochlear implants provide more benefit than conventional hearing aids in prelingually deaf patients. SUMMARY OF THE FINDINGS: The study was a systematic review of scientific papers selected by a search of the SciELO, Cochrane, MEDLINE, and LILACS-BIREME databases. Among the 2169 articles found, 12 studies proved relevant to the issue and presented an evidence strength rating of B. No publications rated evidence strength A. Seven of the studies analyzed were prospective cohorts and 5 were cross-sectional studies. CONCLUSION: Based on several studies, cochlear implants were demonstrated to be the best current alternative for bilateral severe or profound hearing loss, achieving better results in speech perception and development in prelingual children when compared to conventional hearing aids.

Microangiopathy of the inner ear, deafness, and cochlear implantation in a patient with Susac syndrome.

CONCLUSION: The cochlear implant was beneficial as an attempt to restore hearing and improve communication abilities in this patient with profound sensorineural hearing loss secondary to Susac syndrome. OBJECTIVE: To report the audiological outcomes of cochlear implantation (CI) in a young woman with Susac syndrome after a 6-month follow-up period. Susac syndrome is a rare disorder. It is clinically characterized by a typical triad of sensorineural deafness, encephalopathy, and visual defect, due to microangiopathy involving the brain, inner ear, and retina. METHODS: This was a retrospective review of a case at a tertiary referral center. After diagnosis, the patient was evaluated by a multidisciplinary team and received a cochlear implant in her right ear. RESULTS: The patient achieved 100% open-set sentence recognition in noise conditions and 92% monosyllable and 68% medial consonant recognition in quiet conditions after 6 months of implant use. She reported the use of the telephone 3 months after activation.

Speech perception in adolescents with pre-lingual hearing impairment with cochlear implants.

UNLABELLED: Profound hearing loss is a disability that affects personality and when it involves teenagers before language acquisition, these bio-psychosocial conflicts can be exacerbated, requiring careful evaluation and choice of them for cochlear implant. AIM: To evaluate speech perception by adolescents with profound hearing loss, users of cochlear implants. STUDY DESIGN: Prospective. MATERIALS AND METHODS: Twenty-five individuals with severe or profound pre-lingual hearing loss who underwent cochlear implantation during adolescence, between 10 to 17 years and 11 months, who went through speech perception tests before the implant and 2 years after device activation. For comparison and analysis we used the results from tests of four choice, recognition of vowels and recognition of sentences in a closed setting and the open environment. RESULTS: The average percentage of correct answers in the four choice test before the implant was 46.9% and after 24 months of device use, this value went up to 86.1% in the vowels recognition test, the average difference was 45.13% to 83.13% and the sentences recognition test together in closed and open settings was 19.3% to 60.6% and 1.08% to 20.47% respectively. CONCLUSION: All patients, although with mixed results, achieved statistical improvement in all speech tests that were employed.

Speech perception in adolescents with pre-lingual hearing impairment with cochlear implants / Percepção de fala em adolescentes com surdez pré-lingual usuários de implante coclear

Profound hearing loss is a disability that affects personality and when it involves teenagers before language acquisition, these bio-psychosocial conflicts can be exacerbated, requiring careful evaluation and choice of them for cochlear implant. AIM: To evaluate speech perception by adolescents with profound hearing loss, users of cochlear implants. STUDY DESIGN: Prospective. MATERIALS AND METHODS: Twenty-five individuals with severe or profound pre-lingual hearing loss who underwent cochlear implantation during adolescence, between 10 to 17 years and 11 months, who went through speech perception tests before the implant and 2 years after device activation. For comparison and analysis we used the results from tests of four choice, recognition of vowels and recognition of sentences in a closed setting and the open environment. RESULTS: The average percentage of correct answers in the four choice test before the implant was 46.9 percent and after 24 months of device use, this value went up to 86.1 percent in the vowels recognition test, the average difference was 45.13 percent to 83.13 percent and the sentences recognition test together in closed and open settings was 19.3 percent to 60.6 percent and 1.08 percent to 20.47 percent respectively. CONCLUSION: All patients, although with mixed results, achieved statistical improvement in all speech tests that were employed.

A surdez profunda é uma deficiência que afeta a personalidade e quando se trata de adolescentes com surdez profunda pré-lingual, esses conflitos biopsicossociais são exacerbados, necessitando de cautela na avaliação e escolha destes candidatos ao implante coclear. OBJETIVO: Avaliar a percepção de fala em adolescentes portadores de surdez pré-lingual do tipo neurossensorial grave a profunda bilateral com implante coclear. FORMA DE ESTUDO: Prospectivo. CASUÍSTICA E MÉTODO: Vinte e cinco indivíduos com surdez pré-lingual, sensório-neural, de grau severo ou profundo, que foram submetidos ao implante coclear na adolescência, definida entre 10 a 17 anos e 11 meses, passaram por testes de percepção de fala pré-implante e 2 anos após a ativação do dispositivo. Para análise, utilizamos os resultados dos testes de four choice, reconhecimento de vogais e sentenças em conjunto fechado e aberto. RESULTADOS: A média da porcentagem de acertos do teste de four choice antes do implante coclear era de 46,9 por cento e após, 2 anos de uso do dispositivo, a média foi para 86,1 por cento; no teste de vogais, a média foi de 45,13 por cento a 83,13 por cento; e no teste de sentenças em conjunto fechado e aberto foi de 19,3 por cento a 60,6 por cento e de 1,08 por cento a 20,47 por cento, respectivamente. CONCLUSÃO: Embora com resultados heterogêneos, todos obtiveram melhora estatística nos testes aplicados.