Bruce M. Edwards

Recurrent laryngeal nerve monitoring in thyroid and parathyroid surgery: the University of Michigan experience.

Objectives/Hypothesis Intraoperative monitoring of the recurrent laryngeal nerve (RLN) is finding increasing acceptance during thyroidectomy. Recently, a laryngeal surface electrode was introduced to enable another form of noninvasive monitoring of the RLN. The present report examines the University of Michigan experience with RLN monitoring using the postcricoid surface electrode.

Clinical manifestations of CHARGE Association

The clinical literature regarding CHARGE Association is mostly retrospective in nature and deals largely with non-auditory issues related to the care and management of these patients with multisystem involvements. In this paper, we describe the clinical findings in 24 patients evaluated in the Division of Audiology and Electrophysiology at the University of Michigan Medical Center from 1983 to 1993. We report on the clinical manifestations of CHARGE Association in these patients with particular attention paid to their audiologic status. We discuss the relationships between auditory, ear, and craniofacial anomalies. Our review of these previously unreported cases suggests the following: (1) a variety of audiologic outcomes is possible, however, if a sensorineural or mixed hearing loss exists, it tends to be severe in degree; (2) progressive hearing loss does not appear to occur, but recurring otitis media is a probable confounding factor in the early identification of hearing loss; (3) congenital unresolved facial weakness may serve as a reliable predictor of sensorineural hearing loss; and (4) amplification use may be poor due to a number of factors. We hope to offer guidance to the professionals from assorted disciplines who participate in the care of these children.

Effectiveness of Laser Application for Periodontal Surgical Therapy: Systematic Review and Meta-Analysis

BACKGROUND Evidence has shown some improved clinical outcomes and morbidity reduction with the use of lasers for non-surgical periodontal therapy due to ablation, vaporization, hemostasis, and field sterilization. The purpose of this systematic review is to evaluate and compare studies involving lasers as monotherapy or adjunctive to surgical periodontal treatment. METHODS Electronic and manual searches were conducted by two independent reviewers in several databases for articles written in English up to December 2014. Articles were included in this review if they reported outcomes of surgical periodontal therapy with and without the use of lasers. The primary outcome was probing depth (PD), and secondary outcomes were measured changes in clinical factors such as clinical attachment level (CAL) and gingival recession (GR). For the comparative studies included, the pooled weighted mean difference (WMD) and 95% confidence interval (CI) of each variable were calculated using random-effects meta-analysis. RESULTS Eight and nine articles were included in the quantitative and qualitative analyses, respectively. Although low-to-moderate risk of bias was detected, high heterogeneity among studies was found. In flap surgery with or without laser treatment, there was no statistically significant difference in primary outcome. Similarly, in guided tissue regeneration (GTR)/enamel matrix derivative (EMD) with and without laser treatment, the WMD of PD was negligible; however, the GTR/EMD group showed better outcomes (P = 0.005) than the laser group. Regarding the secondary outcomes, in the flap surgery group, the WMD of CAL gain was 1.34 mm, and the WMD of GR was -0.24 mm; no significant difference was detected between groups. In GTR/EMD with and without laser treatment, the WMD of CAL gain was 0.10 mm and the WMD of recession was -0.18 mm; again, no significant difference was detected between groups. CONCLUSIONS The available evidence is insufficient to support the effectiveness of dental lasers as an adjunct to resective or regenerative surgical periodontal therapy. However, precautions must be exercised when interpreting the results of this study because of the small sample size and high heterogeneity among studies.

Transient Evoked Otoacoustic Emissions Pattern as a Prognostic Indicator for Hearing Preservation in Acoustic Neuroma Surgery

Objective: To determine whether pre-operative transient otoacoustic emission (TEOAE) patterns are predictive of successful hearing preservation in acoustic neuroma surgery. Study Design: Retrospective observational study. Setting: Tertiary referral medical center. Patients: A convenience sample was identified in whom pre-operative TEOAE data were available in patients undergoing acoustic neuroma surgery from 1993-2004. Ninety-three patients were identified who met this inclusion criterion. Interventions: Subjects underwent attempted hearing preservation surgery via middle cranial fossa or retrosigmoid approaches. Routine audiometry, ABR, and TEOAE. Main Outcome Measures: Pre- and post-operative pure tone and speech results were categorized into hearing classes A, B, C, and D as described in the American Academy of Otolaryngology guidelines (1995). Hearing preservation was defined by maintenance of the pre-operative hearing class or downgrade to within one hearing class post-op. Pre-operative TEOAE results were divided into five frequency bands and described as positive in each band if there was a response above the noise floor with >50% reproducibility. Results: Hearing was preserved in 51 patients (55%). Of these, 11 (22%) had positive TEOAE response in all five frequency bands measured (1, 1.5, 2, 3, 4 kHz), whereas 40 (78%) had TEOAE responses ranging from 0 to 4 frequency bands. 42 patients failed to preserve their hearing. Of these, only three (7%) had positive TEOAE in all five frequency bands, and 39 (93%) had TEOAE responses ranging from 0 to 4 frequency bands (p < 0.05). Other variables of prognostic significance to hearing preservation in our series included smaller tumor size, tumor location within the IAC, better pre-operative hearing, and shorter latencies on ABR. Logistic regression was then used to compare the prognostic value of TEOAE against these variables. In our series, ABR latencies and 5 frequency band response on TEOAE showed the highest significant correlation to hearing preservation (p < 0.05). Conclusion: A robust pre-operative TEOAE frequency band pattern may be used as a favorable prognostic indicator for potential hearing preservation in acoustic neuroma surgery. The prognostic value may be enhanced when combined with other prognostic factors such as tumor size, tumor location, pre-operative ABR and audiometric results.

Different manifestations of auditory neuropathy.

Auditory neuropathy (AN) is characterized by a range of auditory deficits including elevated pure tone thresholds, reduced speech recognition scores, absence of auditory brainstem responses (ABR), and preservation of evoked otoacoustic emissions and the cochlear microphonic (CM) response. With increased advocacy for early implantation, patients with auditory neuropathy may be considered for implantation at or before one year of age. The decision for early implantation of very young patients with clinical test results that suggest AN should be made cautiously as a subset of patients presenting with the clinical constellation of AN may demonstrate reversible hearing loss over time.