A two-institution retrospective study was undertaken to determine whether two different prepalatoplasty protocols quantitatively affect maxillary arch morphology in infants with complete unilateral cleft lip and palate (UCLP).
Serial maxillary dental casts, obtained at regular intervals through the first 18 months of life from preintervention until palatoplasty were evaluated quantitatively using computer-assisted three-dimensional digitization and analysis for three populations: institution 1 (protocol 1), institution 2 (protocol 2), and unaffected individuals (neither cleft nor treatment). Sequential UCLP patients from institution 1 were matched for age and initial alveolar cleft width, sex and cleft side having been demonstrated to be nonsignificant, with UCLP patients from institution 2 and to unaffected individuals for age for the analysis.
Both treatment institutions are well-established regional interdisciplinary cleft centers. Institution 1 is located in a tertiary, academic children's hospital in a metropolis within a primarily agrarian region of the Midwest; institution 2 is a freestanding private clinic located in a small city within a primarily agrarian region of an eastern state; the unaffected population is a historic archive acquired in the 1930s. Data acquisition (model digitization) and computer processing were performed at institution 1.
Eighty-five casts of 28 infants from institution 1, 106 casts of 31 infants from institution 2, and 68 casts of 29 unaffected infants were analyzed. All infants had alginate impressions taken prior to intervention and at several additional 6-month intervals after that, consistent with each institution's treatment protocol.
At institution 1, patients with UCLP underwent lip adhesion and placement of a passive alveolar molding plate at 7 weeks of age, definitive cheiloplasty at 7 months of age, and one-stage palatoplasty at 14 months of age. At institution 2, patients with UCLP underwent definitive cheiloplasty at 3 months of age, had no maxillary orthopedics, and had vomer flap hard palate repair at 12 months of age and soft palate repair at 18 months of age.
The outcome measures included directly digitized (cleft segment and hemialveolar ridge lengths) and derived (alveolar base width, alveolar cleft gap, maxillary frenum-alveolar base perpendicular angle, and rates of change over time of digitized cleft segment and hemialveolar ridge lengths) features. The data were assessed by comparing simple linear regression lines and an unpaired, two-tailed t test.
Prior to initiating therapy, there were no statistically significant differences between the two populations with clefts. However, both populations with clefts differed significantly from unaffected individuals (p < .001), with increased maxillary base widths and larger perpendicular/frenum angles. At the time of palatoplasty, the two populations with clefts had statistically significant differences between them in the maxillary base width (p < .01) and the cleft gap distance (p < .05). The base width of institution 1 did not differ significantly from that of widths of unaffected children, and that of institution 2 was significantly less, although the latter had already received first-stage palate repair. Alveolar segment growth rates were similar for the greater and lesser segments, respectively, and the left side hemialveolus of both groups. The growth rate for the noncleft side hemialveolus of institution 2 exceeded (p < .05) that of both institution 1 and unaffected patients.
Two different regimens for the initial management of UCLP can significantly affect maxillary alveolar arch growth with respect to the treatment used and in comparison with unaffected controls.