Faculty Bibliography

Hearing impairment and related cochlear histopathologic changes were evaluated in experimental animals after treatment with aminoglycoside antibiotics or exposure to intense sound. In the course of treatment with kanamycin, neomycin, or dihydrostreptomycin, permanent hearing loss in monkeys and guinea pigs occurred first at the high frequencies and progressed toward the lows. Exposure to different octave bands of noise at 120 dB SPL in monkeys and chinchillas produced permanent hearing loss at frequencies related to the spectral characteristics of the octave band. In most instances loss of outer hair cells was substantially greater than that of inner hair cells. In fact, the pattern and location of missing outer hair cells on the basilar membrane were most often correlated with threshold shifts of 50 dB or less. Generally inner hair cell loss was observed when the threshold shift was greater than 50 dB. Our data support the place principle and the inference that the outer hair cells are essential for hearing from threshold to about 50 dB SL. The inner hair cells, if functioning normally, apparently take over above that level. Although there is little doubt that such a generalization will, in the long term, be found to have been greatly oversimplified, there is every reason to believe that a combination of behavioral and morphologic procedures, as used in this study, will play an important part in elucidating the differences in functional significance of the two types of hair cells.

An improved fiberoptic laryngoscope is connected to Timcke's stroboscope. The laryngoscope gives a magnified view of 2x and is prefocused from 5 cm to infinity. The combination of the stroboscope and the laryngoscope gives an excellent slow-motion view of the vocal fold movement.

Acoustic conductance and susceptance tympanograms were obtained at 220 and 660 Hz in 34 neonates. The neonates were categorized into three age groups (8-24 hours, 24-60 hours, and 60-96 hours). Single-peaked, double-peaked, and monotonically increasing tympanograms were found. Static values for conductance, susceptance, admittance, resistance, reactance and impedance at the lateral surface of the tympanic membrane were computed from the tympanograms. There were no significant differences in mean static values among the three groups. At 220 Hz, the individual static reactance values were usually smaller than the static resistance values and often assumed a positive sign. At 660 Hz, the individual static reactance values always assumed a negative sign and were approximately equal to the static resistance values. The single- and double-peaked tympanograms apparently were the result of previously identified interactions between static resistance and reactance values. The data were compared to those of infants and adults. Tympanograms at 220 Hz were obtained for 13 of the original subjects at the age of three to four months. The data collected in this group were consistent with those reported in the literature for the same age group.

Stapedectomy has become recognized as the procedure of choice in the surgical treatment of clinical otosclerosis. Based on results obtained in stapes surgery performed in 1977, profiles were established for hearing improvement, vertigo, tinnitus, chorda tympani injury and temporary threshold shift of high tones. Tympanometric and stapedial muscle reflex tests in cases of proved clinical otosclerosis also are discussed. The profiles indicate that stapedectomy performed on a regular basis and under ideal conditions is highly successful for the improvement of hearing. The incidence and probable causes of complications are presented and discussed. This study reveals, however, that the number of new patients with otosclerosis has decreased steadily since its peak in 1964. Should the number of surgical cases continue to diminish, it may be impossible for the practicing otologist to maintain sufficient expertise for the performance of an occasional stapedectomy. Also, it may become impossible to provide sufficient experience in otosclerosis surgery for all trainees in otolaryngology.

A review of thread augmentation has added helpful points to the technique and given an opportunity to assess the long-range results. It is obvious at this stage that there is no panacea for the wrinkling process. Each technique has advantages and disadvantages. The simplicity and low complication rate of thread augmentation supports this appeal. It is reasonable to state that the full application of the concept of this type of augmentation has not as yet been realized with this ongoing principle. This technique has been found of value when used as a single procedure or in combination with blepharoplasty or rhytidectomy.

There are several basic techniques for obtaining acceptable closure of the orbital defect following exenteration. The approach to reconstructing a socket in the method chosen should be the one that gives the best cosmetic result while not compromising the surgical excision and the possibility of cure. Few surgeons have attempted to correct the deformity of orbital exenteration so that an artificial eye can be worn. We have found that approximately 20% of those patients undergoing radical ablation of the orbit quality for simultaneous reconstruction of the eye socket. The technique of a cheek-eyelid-conjunctiva flap allows for immediate reconsturction of the eye socket and the fitting of a prosthesis.

Because of the anatomy of the deep lobe of the parotid and its restrictive boundaries, retromandibular tumors may be asymptomatic until reaching massive size. Removal by an intraoral approach may be not only disappointing but also disastrous, with disintegration of the tumor and generalized spillage in the wound. Our experience suggests that the best approach to any type of tumor in this region is through the upper lateral cervical tissues with consideration of a mandibular osteotomy if the tumor extends into the retropharynx or the nasopharynx. This review of 12 patients who required osteotomy describes a high success rate with minimal complications.