Orbital osteology: a study of the surgical landmarks.

This study was conducted to re-examine the osteological anatomy of the orbit. Previous studies examined dried human skulls; this study looks at cadaveric specimens in a population that more closely resembles the population in the United States. Measurements were made of the bony orbit to define safe distances for surgical intervention and to identify distances to intraorbital fissures, canals, and foramina. Safe distances to the optic nerve were identified by subtracting 5 mm from the shortest measured specimen. The safe distances were as follows: medial quadrant, 29 mm; inferior quadrant, 39 mm; superior quadrant, 38 mm; and lateral quadrant, 36 mm. Staying close to the bony wall, not exceeding these parameters, and careful identification of anatomical structures should keep the surgeon from inadvertent damage to the intraorbital structures.

Recovery of eustachian tube function and hearing outcome in patients with cleft palate.

Eustachian tube dysfunction is a nearly universal complication of cleft palate, resulting in chronic ear disease and conductive hearing loss. Cleft palate repair is thought to result in recovery of eustachian tube function, but the length of time between repair and recovery of eustachian tube function is not known. Furthermore, the efficacy of tympanostomy tubes in the treatment of eustachian tube dysfunction and hearing sequelae has not been examined in a systematic way. To answer these questions, we performed a retrospective study that used serial audiometric data and tympanometry on 81 patients with cleft palates (162 ears), with follow-up ranging from 1 to 17.3 years. Average time to recovery of eustachian tube function was 6.0 years (range, 1.0 to 10.3 years) after cleft palate surgery. For children followed up for at least 6 years (longest follow-up, 17.3 years), 70% (67 of 85) had normal eustachian tube function at their last follow-up visit. Ears treated with Armstrong tympanostomy tubes required an average of 3.1 tubes per ear until recovery of eustachian tube function, whereas ears treated with Goode T tubes required only 1.1 tubes per ear (p < 0.05). Hearing evaluation revealed that 67% of ears had abnormal hearing thresholds (> 20 dB) before tympanostomy tube placement, whereas only 7.5% of ears demonstrated this loss after tube placement. Furthermore, more than 90% of ears maintained normal thresholds after recovery of eustachian tube function. These data indicate that most children with cleft palates eventually recover normal eustachian tube function after palatoplasty, but for the majority of children, this does not occur for many years.(ABSTRACT TRUNCATED AT 250 WORDS)