Major congenital synechiae of the oral cavity constitute a clinically confusing spectrum of abnormalities. On the basis of clinical data, we propose two categories: 1) abnormalities secondary to persistence of the buccopharyngeal membrane and 2) abnormalities secondary to formation of ectopic membranes. An ectopic membrane results from abnormal fusion and can be subclassified as a subglossopalatal membrane, glossopalatal ankylosis, or syngnathia. This classification is supported by embryologic studies and is used to reclassify all cases reported since 1900. Distinct differences, such as the presence of associated limb anomalies, emerge; these are reviewed and add support to the proposed classification.

Laryngeal injection of botulinum toxin type A is currently the most effective method of treating spasmodic dysphonia. Botox, a crystalline preparation of botulinum toxin type A, is the only toxin approved for clinical use in the United States and is packaged in vials of 100 mouse units (MU). One MU corresponds to the calculated median lethal intraperitoneal dose (LD50) injected in mice. The logistic problems arising from the need for repeated injections of small amounts of Botox have been addressed by several investigators by refreezing unused Botox for use at a later time. Although FDA labeling recommends that Botox not used within 4 hours of reconstitution be discarded, data regarding degradation in potency after reconstitution and refreezing are not currently available. Using the LD50 Swiss-Webster mouse bioassay and statistical analysis by the Probit procedure, a 69.8% loss in potency was found when Botox was reconstituted, immediately frozen, and then assayed 2 weeks later (p < 0.0001). Statistically significant degradation in potency was seen after refrigerator storage for 12 hours (p = 0.007), but not for 6 hours (p = 0.16). Clinical implications regarding the dilution, use, and storage of Botox are discussed.

The relative contributions of the levator veli palatini, palatoglossus, and palatopharyngeus muscles were assessed relative to a range of positions of the velopharynx during production of the vowels [a] and [I] by four normal adult speakers. The results indicate that velopharyngeal positioning is determined by the relative contributions of the levator veli palatini, palatoglossus, and palatopharyngeus muscles. There was an increase In coefficients of determination (i.e., amount of closure level variability explained) when activity levels of all three muscles are included in the statistical model compared to activity in any one muscle analyzed independently. Both consistent and inconsistent relations among activity levels in the three velopharyngeal muscles studied were observed across speaker and vowel produced.

Laryngeal electromyography is a valuable test to assess vocal cord paralysis in adults. This technique can be applied and adapted to the pediatric patient. In the operating room under general anesthesia and endoscopic guidance, bipolar hooked-wire electrodes are passed percutaneously through the anterior neck skin into both thyroarytenoid muscles. Electromyographic signals are evaluated during light anesthesia and on awakening. A critical appraisal of this technique is presented, including an analysis of sources of electrical interference in the operating room.

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