subject: Cleft Lip and Other Malformations [print this page] Cleft Lip and Other Malformations Cleft Lip and Other Malformations
Recent litigation has brought to light the possible link between some medications and birth defects such as cleft lip and cleft palate. One interesting article is called, "Association Between Cleft Lip With Or Without Cleft Palate And Prenatal Exposure To Diazepam" The Lancet, Volume 306, Issue 7933, Pages 478-480 by M.Safra. Here is an excerpt: "Abstract - From 278 interviews of women who had infants with selected major malformations, a history of diazepam ingestion in the first trimester of pregnancy was found to be four times more frequent among mothers of children with a cleft lip with or without a cleft palate than among mothers of children with other defects. This association was one of many that was examined in the analysis; thus it is quite possible that it is simply due to chance. This report, however, is the second one linking diazepam to cleft lip with or without cleft palate. Until there are more data bearing on this question, this possible risk should be considered when prescribing diazepam for women in their reproductive years."
Another interesting article is called, "Association of genetic variation of the transforming growth factor-alpha gene with cleft lip and palate." By H H Ardinger, K H Buetow, G I Bell, J Bardach, D R VanDemark, and J C Murray - Department of Pediatrics, University of Iowa, Iowa City 52242. Am J Hum Genet. 1989 September; 45(3): 348353. Here is an excerpt: "Complex segregation analysis of pedigrees having nonsyndromic cleft lip with or without cleft palate (CL/P) (Chung et al. 1986; Marazita et al. 1986) has shown that a major-locus model best explains the observed recurrence of CL/P in Caucasian families. To identify this major gene, we compared the frequencies of 12 RFLPs at five loci-epidermal growth factor, transforming growth factor-alpha, epidermal growth factor receptor, glucocorticoid receptor, and estrogen receptor-in both a group of 80 subjects with nonsyndromic CL/P and 102 controls. These candidate genes were selected because studies in rodents had suggested their possible involvement in palatogenesis. A significant association was observed between two RFLPs at the transforming-growth-factor-alpha (TGFA) locus and the occurrence of clefting (P = .0047 and P = .0052). This suggests that either the TGFA gene itself or DNA sequences in an adjacent region contribute to the development of a portion of cases of CL/P in humans and provides an opportunity to begin to examine the molecular events underlying lip and palate formation."
Another interesting study is called, "Secondary Bone Grafting of Alveolar Clefts: A Surgical/Orthodontic Treatment Enabling a Non-prosthodontic Rehabilitation in Cleft Lip and Palate Patients" 1981, Vol. 15, No. 2 , Pages 127-140 by Frank E. byholm1, Olav Bergland1 and Gunvor Semb - Department of Plastic Surgery, Rikshospitalet; the Department of Odontology, National Center for Logopedics; and the Department of Orthodontics, Dental Faculty, University of Oslo, Oslo, Norway. Here is an excerpt: "A procedure combining grafting of cancellous bone to the residual cleft of the primary palate with subsequent orthodontic movement of teeth into the former cleft area is described. The preliminary results from the first 80 patients (89 clefts) are presented. The age of the patients at the bone grafting ranged from 8 to 18 years, and the observation time from 17 to 44 months. The results have been assessed 1) on the basis of dental radiographs and 2) clinically, by the response of the grafted area to the orthodontic movement of adjacent teeth. In 69 clefts in which the cleft side canine had been brought into its final position at the time of evaluation, the height of the interal-veolar septum was assessed to be approximately normal in 38% and slightly less than normal in 44%. A septum of insufficient height (less than 3/4 of the normal) had formed in 5 clefts (7%). Even in these cases, the main objects of the operation were fulfilled: The maxillary segments were stabilized, the teeth adjacent to the cleft had better bone support, and the gap in the dental arch could be closed orthodontically in four of the five clefts. Failures, i.e. no continuous bone bridge across the alveolar cleft, were recorded in 8 instances (9%) of the total material."
We all owe a debt of gratitude to these researchers for their fine work and dedication. For more information, please read the studies in their entirety.
