Acoustic role of the buttress and posterior incudal ligament in human temporal bones.

OBJECTIVES: In middle ear surgery using intact ear canal wall techniques, the buttress, which is the bony bridge at the medial end of the posterior-superior bony ear canal, is commonly retained during posterior tympanotomy. In some cases, the surgical exposure may be improved by resectioning the buttress, and this requires sectioning the posterior incudal ligament. To date, the acoustic effects of removing the buttress with sectioning of the attached ligament have not been studied. METHOD: Using a laser Doppler vibrometer system, 15 human cadaver temporal bones were measured with 80 dB sound pressure level at the tympanic membrane over the 0.1 to 10 kHz frequency range. RESULT: The resection of the buttress and sectioning the posterior incudal ligament had no effect on stapes footplate velocity. CONCLUSION: These results suggest that the posterior incudal ligament does not play a significant role in the acoustic function of the ossicles.

Human middle-ear sound transfer function and cochlear input impedance.

The middle-ear pressure gain, defined as the ear canal sound pressure to cochlear vestibule pressure gain, GME, and the ear canal sound pressure to stapes footplate velocity transfer function, SVTF, simultaneously measured in 12 fresh human temporal bones for the 0.05 to 10 kHz frequency range are reported. The mean GME magnitude reached 23.5 dB at 1.2 kHz with a slope of approximately 6 dB/octave from 0.1 to 1.2 kHz and -6 dB/octave above 1.2 kHz. From 0.1 to 0.5 kHz, the mean GME phase angle was 51 degrees, rolling off at -78 degrees /octave above this frequency. The mean SVTF magnitude reached a maximum of 0.33 mm s(-1)/Pa at 1.0 kHz with nearly the same shape in magnitude and phase angle as the mean GME. The ratio of GME and SVTF provide the first direct measurements of Z(c) in human ears. The mean Z(c) was virtually flat with a value of 21.1 acoustic GOmega MKS between 0.1 and 5.0 kHz. Above 5 kHz, the mean Z(c) increased to a maximum value of 49.9 GOmega at 6.7 kHz. The mean Z(c) angle was near 0 degrees from 0.5 to 5.0 kHz, decreasing below 0.5 kHz and above 5 kHz with peaks and valleys.

The temporalis muscle flap for reconstruction after head and neck oncologic surgery.

OBJECTIVE: To explain the applications, technique, and potential complications of the temporalis muscle flap used for immediate or delayed reconstruction of head and neck oncologic defects. STUDY DESIGN: Fresh cadaver dissection and 5-year retrospective chart review. METHODS: A fresh cadaver dissection was performed to illustrate the surgical anatomy of the temporalis muscle flap with attention to specific techniques useful in avoiding donor site morbidity (facial nerve injury and temporal hollowing). A chart review was performed for 13 consecutive patients from the last 5 years who underwent temporalis muscle flap reconstruction after oncologic resection of the lateral and posterior pharyngeal wall, hard and soft palate, buccal space, retromolar trigone, and skull base. RESULTS: Patient follow-up ranged from 2 to 45 months. Nine patients had radiation therapy. There were no cases of flap loss. Resection of the zygomatic arch followed by wire fixation facilitates flap rotation and minimizes trauma to the flap during placement into the oropharynx. Preservation of the temporal fat pad attachment to the scalp flap decreases temporal hollowing and protects the facial nerve. Replacing the zygoma and preserving the anterior third of the temporalis muscle in situ further diminishes donor-site hollowing. CONCLUSIONS: Compared with other regional flaps, such as the pectoralis myocutaneous flap, the temporalis muscle flap is associated with low donor-site esthetic and functional morbidity and offers great flexibility in reconstruction. The temporalis muscle flap is a useful, reliable flap that belongs in the armamentarium of surgeons who are involved with reconstruction of head and neck tissue defects.

Current status of topical nasal antimicrobial agents.

The nasal cavity and paranasal sinuses are probably one of the last frontiers in the head and neck region where the use of topical antimicrobial agents is not yet established. Although the anatomy of the nasal cavity and the paranasal sinuses can theoretically be exploited for the administration of antimicrobials in rhinosinusitis, very few studies have been conducted to test the feasibility of this mode of therapy. We review the anatomical and physiological factors that should be considered in the use of topical nasal antimicrobial agents and the current status of topical nasal antimicrobial usage, and we make recommendations for the administration of topical nasal antimicrobial agents.

Kinetic analysis of LY320236: competitive inhibitor of type I and non-competitive inhibitor of type II human steroid 5alpha-reductase.

Type I and type II steroid 5alpha-reductases (5alpha-R) catalyze the conversion of testosterone (T) to dihydrotestosterone (DHT). LY320236 is a benzoquinolinone (BQ) that inhibits 5alpha-R activity in human scalp skin (Ki(typeI)=28.7+/-1.87 nM) and prostatic homogenates (Ki(typeII)=10.6+/-4.5 nM). Lineweaver-Burk, Dixon, and non-linear analysis methods were used to evaluate the kinetics of 5alpha-R inhibition by LY320236. Non-linear modeling of experimental data evaluated V(max) in the presence or absence of LY320236. Experimental data modeled to the following equation 1v=+ fixing the In0c value equal to 1.0 or 0 are consistent with non-competitive or competitive inhibition, respectively. LY320236 is a competitive inhibitor of type I 5alpha-R (In0c=0, Ki=3.39+/-0.38, RMSE = 1.300) and a non-competitive inhibitor of type II 5alpha-R (In0c=1, Ki=29. 7+/-3.4, RMSE = 0.0592). These data are in agreement with linear transformation of the data using Lineweaver-Burk and Dixon analyses. These enzyme kinetic data support the contention that the BQ LY320236 is a potent dual inhibitor with differing modes of activity against the two known human 5alpha-reductase isozymes. LY320236 represents a class of non-steroidal 5alpha-R inhibitors with potential therapeutic utility in treating a variety of androgen dependent disorders.

Advantages of a new miniature hearing aid for mild to moderate hearing loss.

OBJECTIVES/HYPOTHESIS: To evaluate the performance of a new, miniature, behind-the-ear hearing aid designed for individuals with mild to moderate high-frequency hearing loss who need an aid but are reluctant to try one. The aid is essentially invisible, leaves the ear canal open, and can be fit in less than 30 minutes without an ear impression. The cost is less than $500. STUDY DESIGN: A 4-week trial of the aid in 63 ears (62 subjects) with mild to moderate bilateral hearing loss. METHODS: A questionnaire was completed at the end of the study by each subject asking them to evaluate several features of the aid (cosmesis, comfort, understanding speech, amplification, and so forth) and to compare their unaided performance in quiet and in noise with the test hearing aid. A rating scale of 1 to 10 was used, with 10 being excellent and 1 poor. RESULTS: Subjective improvement in understanding speech in both quiet (5.8-->7.3) and noise (4.6-->5.9) occurred with the aid. Cosmesis, comfort, and appearance were highly rated (mean scores, > 8). CONCLUSIONS: This aid appears to have several features (comfort, cost, performance, and cosmesis) that make it ideal as a first aid for patients with mild to moderate losses.

Growth regulation of prostatic stromal cells by prostate-specific antigen.

BACKGROUND: Prostate-specific antigen (PSA) is a serine protease that can cleave insulin-like growth factor-binding protein-3 (IGFBP3), thereby decreasing its affinity for insulin-like growth factor-I (IGF-I). Dissociation of the IGF-I-IGFBP3 complex renders IGF-I available to bind to its receptor and stimulates cellular proliferation. We evaluated the potential for PSA to modulate the effects of IGF-I and IGFBP3 on the proliferation of human benign prostatic hyperplasia (BPH)-derived fibromuscular stromal cells in primary cultures. METHODS: We cultured BPH-derived stromal cells for 48 hours in serum-free RPMI-1640 medium supplemented with 0.2% bovine serum albumin and studied the effects of IGF-I, IGFBP3, PSA, and ZnCl(2) at varying concentrations. Differences in cell growth between control and treated cultures were evaluated by use of Dunnett's test. Concentration-related trends were evaluated by linear regression of log-transformed concentrations of test reagents on BPH-derived stromal cell number responses. Statistical tests were two-sided. RESULTS: We observed a concentration-dependent proliferative response of BPH-derived stromal cells to IGF-I. IGFBP3 inhibited this response in a concentration-dependent fashion. IGFBP3 alone had no effect on stromal cell proliferation. When stromal cells were incubated with PSA alone or with PSA, IGF-I, and IGFBP3, an increase in stromal cell numbers that was dependent on PSA concentration was evident in both instances. Zinc, an endogenous inhibitor of PSA enzymatic activity, was able to attenuate the stimulatory effect of PSA at intraprostatic physiologic concentrations. CONCLUSIONS: These results are consistent with the idea that PSA can modulate in vitro interactions between IGF-I and IGFBP3 and suggest that PSA may play a role in the regulation of human prostatic fibromuscular cell growth.

Who needs a sleep test? The value of the history in the diagnosis of obstructive sleep apnea.

Many experts believe that a polysomnogram to screen for obstructive sleep apnea should be performed on every patient who has a history of loud snoring and sleepiness. In contrast, the author believes that with a careful history and physical examination, there is no need to study all such patients, at least not until home polysomnography units become as convenient and economical as pulse oximetry.

Evaluation of a cement incus replacement prosthesis in a temporal bone model.

In reconstruction of the ossicular chain for a damaged incus, it is important that the incus replacement prosthesis (IRP) length is ideal in order to provide optimal tension between the tympanic membrane or malleus and stapes head to achieve the best post-operative hearing result. Even though the length of commercially available IRPs can be adjusted, it still may be difficult to achieve clinically. We describe experiments in a human temporal bone model using dental cement as an IRP after removal of the incus. This cement IRP (CIRP) hardens in situ and becomes the length of the gap to be spanned so that tension should be ideal. Two different CIRPs were studied; one was a conventional rod-type CIRP connecting either the umbo or mid-malleus handle to the stapes head. The second was a Y-shaped CIRP (Y-CIRP), connecting two sites on the malleus to the stapes head. The wide Y-CIRP connected the malleus head and umbo to the stapes head, while the narrow Y-CIRP connected the malleus neck and mid-handle to the stapes head. The acoustic performance of these experimental CIRPs was studied using a laser Doppler vibrometer system in 12 fresh human temporal bones. The CIRP demonstrated better acoustic performance than conventional IRPs studied previously in the same model. While all the CIRPs showed similar function below 2.0 kHz, the narrow Y-CIRP appeared best above 3.0 kHz. A prosthesis of this type may have an acoustic advantage over conventional IRPs.

Analysis of the best site on the stapes footplate for ossicular chain reconstruction.

Experiments were performed in 22 fresh human temporal bones to compare the relative acoustic function of three stapes footplate sites for an incus stapes superstructure replacement prosthesis (I-SRP). The three sites evaluated were the anterior, centre and posterior footplates. A new round window (RW) measurement method was used to make the comparisons. A small glass microsphere was placed in the centre of the RW as a target. A Polytec laser Doppler vibrometer was used to measure round window displacement in response to 50 pure tones between 200 and 10,000 Hz presented at 80 dB SPL at the tympanic membrane (TM). After a baseline measurement of RW displacement in the intact temporal bone, the incus was removed and a cement I-SRP (CIRP) formed between the mid-malleus handle and each of the three test footplate sites, in random order. RW displacement was again measured after placement of the CIRP at each of three sites. We found the centre site to be 3.0-7.0 dB better than the anterior site above 2,000 Hz. There were no differences between the anterior and centre sites below 2,000 Hz. The posterior site was the worst at all frequencies.

Radiofrequency energy tissue ablation for the treatment of nasal obstruction secondary to turbinate hypertrophy.

OBJECTIVE/HYPOTHESIS: We hypothesized that the success rate of radiofrequency energy (RFe) tissue ablation of the inferior turbinate for nasal obstruction achieved by previous investigators would be improved by using a longer needle electrode and creating two lesions per turbinate. METHODS: Ten patients with nasal obstruction secondary to inferior turbinate hypertrophy were prospectively enrolled. A 40-mm needle delivered RFe to two sites in each inferior turbinate. Patients used a visual analog scale (VAS) to grade nasal obstruction preoperatively and at 1 week and 8 weeks after surgery. Preoperative and postoperative digital images of the nasal cavity were graded for obstruction (0% to 100%) in a blinded manner. RESULTS: All patients (100%) were subjectively improved at 8 weeks. Mean obstruction (VAS) improved from 50%+/-21% to 16%+/-15% (right side) and from 53%+/-29% to 13%+/-13% (left side). Mean improvements were 68% (right side) (P = .004) and 75% (left side) (P = .001). Mean obstruction graded during blinded review of nasal cavity images improved from 73.5%+/-8% to 51%+/-8% (right side) and from 76%+/-6% to 64%+/-7% (left side). Of nine patients using medications for nasal obstruction before treatment, eight (89%) noted no further need for medications at 8 weeks. CONCLUSION: The use of RFe for submucosal tissue ablation in the hypertrophied inferior turbinate is an effective modality for reducing symptoms of nasal obstruction. Improved results may occur by using a longer needle and creating two lesions per turbinate. Of patients in this study, 100% reported improvement of nasal obstruction.

A human temporal bone study of stapes footplate movement.

OBJECTIVE: This study was designed to determine whether stapes movement is pistonlike or complex. BACKGROUND: The literature provides conflicting information on whether stapes footplate motion is only pistonlike or has other types of movement, such as hingelike or rocking. METHODS: Using 10 freshly harvested human cadaver temporal bones, 3 targets were placed on the stapes footplate through an extended facial recess approach. The targets were 0.5-mm pieces of reflective adhesive material positioned on the long axis of the footplate at the anterior crus, central footplate, and posterior crus. Displacement and phase of the three targets were measured from 0.2 to 10 kHz at a 90dB sound pressure level input at the tympanic membrane. The measuring system was a sophisticated laser Doppler vibrometer (LDV). A computer program (Tymptest) calculated footplate displacement and relative phase at the three sites and the ratio of anterior-posterior rocking movement of the footplate long axis to displacement at the center. RESULTS: Below 2.0 kHz, stapes vibration is predominately pistonlike. Above 2.0 kHz, anterior-posterior rocking motion increases logarithmically with frequency, and, near 4.0 kHz, rocking and pistonlike motion are approximately equal. CONCLUSIONS: Stapes footplate vibration is primarily pistonlike up to 2.0 kHz but becomes more complex at higher frequencies because of an increase in anterior-posterior rocking motion. Hingelike movements were not observed. This information may be helpful in the design of ossicular replacement prostheses that mimic or improve upon normal stapes vibration.

Radiofrequency ablation of the nerve to the corrugator muscle for elimination of glabellar furrowing.

Glabellar furrows are caused by hyperdynamic activity of the corrugator supercilii muscles. A minimally invasive, percutaneous technique for eliminating glabellar furrows is described. An insulated, bipolar needle is inserted vertically through the eyebrow skin to entrap the corrugator nerve plexus. To confirm proper positioning, a stimulating current is delivered to the needle during observation of corrugator supercilii muscle response. Radiofrequency energy is then delivered to the needle, thereby ablating the intervening nerve tissue. This technique is in the early stage of optimization and is being evaluated in an ongoing Stanford University Human Subjects protocol, Stanford, Calif. The preliminary results are reported herein.

Efficacy of octyl-2-cyanoacrylate tissue glue in blepharoplasty. A prospective controlled study of wound-healing characteristics.

OBJECTIVE: To compare the surgical efficacy and wound-healing characteristics of the tissue adhesive octyl-2-cyanoacrylate (approved by the Food and Drug Administration) with traditional suture closure in upper blepharoplasty. METHODS: Prospective, randomized, blinded study comparing cosmetic and functional outcome and time efficiency. Twenty subjects underwent upper eyelid blepharoplasty. Each patient had a control side and an experimental side determined randomly. One eyelid incision was closed with octyl-2-cyanoacrylate (Dermabond; Ethicon Inc, Somerville, NJ) tissue glue, and the other with 6.0 suture (polypropylene or fast-absorbing gut). Comparisons were performed for the time for closure by each method, wound healing, and patient satisfaction. Macrophotographs of the wounds at 1, 2, and 4 weeks after surgery were graded by 5 observers blinded to the closure method, using a 10-point scale and a modified Hollander wound evaluation scale. RESULTS: No statistically significant difference was found between the quality of octyl-2-cyanoacrylate closure and suture closure at 1 month. There were no differences in wound complications, duration of healing, inflammation, or final incision appearance. By 2 weeks, the sides were indistinguishable in 15 (75%) of the patients. Time for closure averaged 7 minutes with suture and 8 minutes with glue. CONCLUSIONS: Octyl-2-cyanoacrylate glue is an excellent alternative to suture closure, producing equivalent quality of closure at all time points and no difference in appearance. This adhesive was sufficient to withstand the forces of closure in upper eyelid blepharoplasty without dehiscence in the absence of sutures.

Prevention and correction of temporal hair loss in rhytidectomy.

Routine incisions in the temporal area for rhytidectomy often remove hair-bearing skin anterior to the ear. This results in a cosmetic deformity, making the surgical intervention clearly visible. This is especially problematic for revision rhytidectomy or for patients with naturally high hairlines. This article describes a systematic approach to the temporal hairline and introduces a novel, hair-bearing, transposition flap that corrects iatrogenic loss of the preauricular tuft of hair.

Cavernous sinus syndrome caused by a primary paranasal sinus non-Hodgkin's lymphoma.

Although uncommon, non-Hodgkin's lymphomas occasionally arise from the nose and paranasal sinuses. Rarely, they may invade into the cavernous sinus and produce signs and symptoms that characteristically include unilateral ophthalmoplegia, sensation loss in the distribution of the ophthalmic and other divisions of the trigeminal nerve, sympathetic nerve paralysis and proptosis. In this report, we present a case of cavernous sinus syndrome (CSS) caused by infiltration of non-Hodgkin's lymphoma from the adjacent paranasal sinuses and address issues regarding its diagnosis and treatment.

Direct bonded orthodontic brackets for maxillomandibular fixation.

OBJECTIVES/HYPOTHESIS: Mandibular fracture treatment often includes arch bar maxillomandibular fixation (MMF), either alone or in combination with open reduction/internal fixation (ORIF) techniques. The glove perforation rate associated with arch bar placement, the incidence of blood-borne pathogen positivity in facial fracture patients, and the injurious effects of arch bars on dental enamel and gingiva have prompted the development of safer alternatives to arch bar MMF. This study evaluates the efficacy, ease of use, and safety profile of one such alternative: orthodontic direct bonded bracket fixation (MMF/DBB). STUDY DESIGN: Prospective study of consecutive mandible fracture patients treated with MMF/DBB. METHODS: Thirty-two patients with mandibular fractures were evaluated from January 1994 to July 1997. Fourteen were appropriate for treatment with MMF/DBB (12 men and two woman; mean age, 24.6+/-7.2 y; range, 16-42 y). Fracture sites included symphysis, angle, condylar neck, coronoid, and body. Nine patients underwent MMF/DBB alone; five underwent MMF/DBB with subsequent ORIF. RESULTS: No infection, malocclusion, malunion/nonunion, or enamel/ gingiva injury occurred. Mean follow-up was 6 months (range, 1-12 mo). Oral hygiene with MMF/DBB was superior to historical controls using arch bars. CONCLUSIONS: MMF/DBB can serve as the single treatment method with satisfactory results in patients with favorable, less complicated mandible fractures, although with increased experience, we have treated several more complex cases with MMF/DBB alone. In cases necessitating ORIF, MMF/DBB can be performed preoperatively to align fracture segments and reestablish occlusion. This facilitates placement of osteosynthesis plates and reduces ORIF operative time. MMF/DBB is an economical, safe technique that minimizes blood-borne-pathogen risk to the operative team, eliminates periodontal injury, facilitates postoperative dental hygiene, and is painless to apply and remove.

The failing flap in facial plastic and reconstructive surgery: role of the medicinal leech.

OBJECTIVE: To review the use of the medicinal leech, Hirudo medicinalis, in salvaging the failing, venous-congested flap. A protocol for the use of leeches is presented. Four illustrative cases of failing flaps (pectoralis major, midline forehead, and temporalis) are presented. STUDY DESIGN: Literature review comprised of MEDLINE search 1965 to present. Retrospective review of four cases involving the management of the failing, venous-congested flap. METHODS: A retrospective review of four cases of failing, venous-congested flaps was performed. RESULTS: The authors' experience, as well as the data from the reviewed medical literature, demonstrates the importance of early intervention in order to salvage the failing, venous-congested flap. Leeches are an immediate and efficacious treatment option. CONCLUSIONS: 1. Review of the literature indicates that the survival of the compromised, venous-congested flap is improved by early intervention with the medicinal leech. H medicinalis injects salivary components that inhibit both platelet aggregation and the coagulation cascade. The flap is decongested initially as the leech extracts blood and is further decongested as the bite wound oozes after the leech detaches. 2. When a flap begins to fail, salvage of that flap demands early recognition of reversible processes, such as venous congestion. The surgeon must be familiar with the use of leeches and should consider their use early, since flaps demonstrate significantly decreased survival after 3 hours if venous congestion is not relieved. In the four cases presented, a standardized protocol facilitated early leech use and provided for the psychological preparation of the patient, availability of leeches, and an antibiotic prophylaxis regimen. 3. The complications associated with leech use can be minimized with antibiotic therapy, wound care, and hematocrit monitoring. 4. The use of the medicinal leech for salvage of the venous-congested flap is a safe, efficacious, economical, and well-tolerated intervention.

Closed dressings after laser skin resurfacing.

OBJECTIVE: To evaluate the safety, efficacy, and patient acceptance of closed dressings after full facial resurfacing with the carbon dioxide laser. DESIGN: Prospective cohort of men and women undergoing full facial carbon dioxide laser resurfacing. SETTING: Ambulatory surgical center at a university hospital. PATIENTS: Forty consecutive patients randomized to 1 of 4 dressing groups. INTERVENTIONS: All patients underwent full facial resurfacing with a carbon dioxide laser system. One of 5 closed dressings (single- or 3-layer composite foam, plastic mesh, hydrogel, or polymer film) was placed immediately after the procedure. Closed dressings were changed on postoperative day 2 and removed on postoperative day 4. OUTCOME MEASURES: Objective postoperative criteria of erythema, scarring, reepithelialization, and surface irregularities were recorded and photodocumented. Comparisons were made among the closed dressing groups as well as with a group of historical control subjects treated with open dressings. The ease of application, office time for preparation and application, and cost of the individual dressings were collected. Patient characteristics of overall acceptance, comfort, and ease of maintenance were recorded with a visual analog scale. RESULTS: There were no complications of scarring, surface irregularities, or contact dermatitis from the application or maintenance of the closed dressings. There were no significant differences in the number of days of postoperative erythema or in the rate of facial reepithelialization among the groups. Most patients preferred not to continue with the closed dressings past 2 days. Positive features from the use of closed dressings included reduction in crust formation, decreased pruritus, decreased erythema, and decreased postoperative pain, compared with historical controls. Negative features included time in preparation and application of the dressings. Costs ranged from $9.79 to $50 per dressing change. CONCLUSIONS: Closed dressings are safe and offer benefits noted during the first 4 postoperative days. Patients can be expected to maintain a closed dressing for at least 24 hours but no longer than 4 days. The positive features of closed dressings and patient acceptance outweigh the cost and office time involved with their application and maintenance.