Prenatal Cleft Lip and Maxillary Alveolar Defect Repair in a 2-Step Fetal Lamb Model
Purpose
As there is no satisfying animal model simulating the complex cleft lip and palate anatomy in a standardized defect on one hand, and comprising the possibilities for extensive surgical procedures on the other hand, an improved fetal lamb model for cleft surgery was developed.
Materials and Methods
Prior to the main study with 16 animals, a pilot study with 4 lambs was conducted. In the pilot study, the unilateral defect was induced at 75 days of gestation. Within 22 days the defect was repaired in 3 lambs; 1 lamb remained unoperated. Disappointing results from the pilot study led to an earlier defect induction (60 to 64 days of gestation) and earlier repair (71 to 84 days) in the main study with 16 lambs. The subsequent delayed repair of the defect was carried out using a Tennison-Randall technique in 10 lambs. In 4 lambs the defect was repaired postnatal, using the same technique. Two lambs had to be excluded from the study. After being euthanized, all animals were investigated macro- and microscopically.
Results
According to our criteria, the esthetic results ranged from satisfactory to good. Cutis and mucosa showed a full recovery whereas subcutis and the orbicularis oris muscle showed healing with scar formation. On average the operated lips were 9% shorter and were also thinner than the contralateral control side.
Conclusions
In this study, the results of the closure of a standardized lip and maxillary alveolar defect in several stages of gestation were documented. Early intervention led to better esthetic results, but increased the risk of abortion by 25%. There was no prevention of scarring in subcutaneous and muscle tissue. Because there was no alignment of the orbicularis oris muscle, the goal of a functional perfect result was not achieved.
⁎Department of Oral and Maxillofacial Surgery, Friedrich-Wilhelms-University of Bonn, Bonn, Germany.
†Professor, Department of Obstetrics, UZ Gasthuisberg, Leuven, Belgium.
‡Professor, Department of Orthodontics, Friedrich-Wilhelms-University of Bonn, Bonn, Germany.
§Professor, Department of Orthodontics and Oral Biology, Radboud University, Nijmegen, The Netherlands.
∥Professor, Department of Oral and Cranio-Maxillofacial Surgery, Radboud University, Nijmegen, The Netherlands.
Address correspondence and reprint requests to Dr Bergé: Department of Oral and Cranio-Maxillofacial Surgery, Radboud University, Nijmegen, Geert Grooteplein-Zuid 14, 6525 GA Nijmegen, The Netherlands
ABSTRACT