The incidence of cleft lip/palate is 1/750 making it one of the most common congenital malformations. Typically, surgical closure of the lip is performed around 3 months of age and palatal closure by 12-24 months. Following surgical repair of the lip and palate, maxillary retrusion generally becomes a prominent morphologic feature, and it has long been purported that it is tissue scarring and contracturing following closure of the palate that creates aberrations in midfacial growth. However, there is growing evidence that impaired growth may be related more to surgical repair of the lip than to palatal surgery. The University of Florida (UF) in collaboration with the University of Sao Paulo (USP), Brazil is proposing a two-year prospective randomized, controlled study to determine whether lip repair by the Spina and Millard techniques results in different levels of resting lip pressure against the alveolus and teeth. The Spina procedure is generally used throughout Brazil while the Millard technique is commonly used in the US. Subjects will be randomly selected from a cohort of 608 unilateral cleft lip and palate infants currently being entered into a collaborative NIDR R01 study being conducted by these two centers. Lip pressure will be assessed using an electrical pressure transducer with a range of 0 to 10 psi. The transducer will be embedded in silastic and curved to fit between the anterior maxillary alveolus and the upper lip. The transducer will be connected to a signal conditioning and indicator unit which provides a 5 VDC excitation voltage, amplifies and displays the output on a digital display chart. All 200 cleft lip patients will be assessed for resting lip pressure at the time of surgery and at their regularly scheduled postoperative evaluations at USP (6, 12, 18 and 24 months) following surgery. The 200 normal control infants will be assessed in the pediatric clinics at the University of Florida. Lip pressure will be assessed at midline, as well as right and left of midline. This study represents a unique opportunity to further our understanding of whether two different and commonly used surgical techniques for the repair of cleft lip result in quantifiably different levels of resting lip pressure against the alveolus and teeth. Findings of differences in resting lip pressure relative to surgical technique and/or between the cleft infants and normal controls will provide the basis for subsequent long-term assessment of midfacial growth patterns.
