Robert J. Shprintzen

The accuracy of measurements of three-dimensional computed tomography reconstructions

PURPOSE The purpose of this study was to evaluate the accuracy and reproducibility of linear measurements obtained from three-dimensional reconstructions of computed tomography (CT) scans. MATERIALS AND METHODS Ten rectangular acrylic blocks were prepared with titanium molybdenum alloy (TMA) markers spaced from 1 to 10 mm, respectively. A plastic sphere was prepared with 10 sets of TMA markers spaced at variable intervals of 1 to 10 mm. Each object was scanned three times at 3-mm slice thicknesses and 1.5 mm with 0.5 mm overlap slice thicknesses, as well as positioned in the CT scanner in two different directions (perpendicular and parallel) to the scanning beam. Intermarker distances of the reconstructed objects were then measured using the measurement tool of the MediCAD software and compared with measurements taken by hand with a vernier caliper. RESULTS Using the 3-mm cut protocol, the data indicated that inconsistency exists between intermarker distance in the scans when the rectangular objects were scanned parallel to the scanning beam. This finding was not seen using the 1.5-mm with 0.5-mm overlap slice thickness protocol. The intermarker distances for objects scanned perpendicular to the scanning beam were consistent but subject to demagnification in the range of 17% to 20% for both scanning protocols. CONCLUSION The orientation of the object to the scanning beam and slice thickness protocol appear to have an impact on the accuracy and variability of linear measurements taken in the x, y, z axes.

The role of adenoids in the development of normal speech following palate repair

The controversy surrounding the various approaches to palate repair continues unabated. Issues which have been studied relative to the development of normal speech following palate repair have included surgical technique and the timing of surgery. However, regardless of the various refinements in surgery, a percentage of children require secondary surgery to resolve velopharyngeal insufficiency. To date, other factors which might be responsible for the development of normal speech have been ignored. The purpose of this report is to discuss the importance of the relative size of the adenoids in relation to the success or failure of primary palatoplasty. Velopharyngeal valving in noncleft (normal) children was also observed. Eight hundred fifty children with nonsyndromic clefts and 138 children with syndromic clefts were analyzed for speech results postpalatoplasty relative to adenoid size. One hundred normal children were also studied. The data suggest a strongly positive correlation between the incidence of hypernasal resonance postpalatoplasty and relative adenoid size in the cleft children. Velar‐adenoidal closure was consistently observed in both the cleft and normal children.

The bifid uvula: is it a marker for an otitis prone child?

All children seen by a pediatrician in a suburban practice during an 18‐month interval were examined carefully for the presence of an abnormal uvula. Isolated bifid uvula, without overt cleft palate, was detected among 44 children who had been followed in the practice during the first three years of life. A chart review was performed to determine the frequency of acute otitis media (AOM) and of insertion of tympanostomy tubes among these study patients and among age‐matched controls with normal uvulas. Compared to control children, a slightly higher proportion of children with bifid uvulas had experienced more than one episode of AOM (64% vs. 49%) and more than three episodes of AOM (16% vs. 8%) during the first year of life, but these differences were not statistically significant. By age 3 years, the incidences of AOM in the compared groups were more nearly equal. Insertion of tympanostomy tubes during the first three years of life for persistent middle ear effusion was slightly more common among the bifid uvula group than among the controls (14% vs. 10%), but this difference again was not statistically significant. Children with bifid uvula may be at slightly increased risk of middle ear problems during the first years of life, but the magnitude of this increase, if any, appears small.