Pulmonary stenosis with ventricular septal defect, common aorticopulmonary trunk, and dextroposition of the aorta: morphologic and qualitative physiologic effects in caffeine-treated chick embryos

Effects of caffeine administration to Hamburger-Hamilton stage 19 chick embryos (3 days of incubation) were investigated. A morphologic study of the effect of caffeine on cardiogenesis showed that caffeine produced total cardiac malformations in the chick in a dose-related fashion. A maximum frequency of 70.6% was observed with 4.7 mg caffeine. Major malformations included common aorticopulmonary trunk and dextroposition of the aorta accompanied by ventricular septal defect with/without pulmonary stenosis. Qualitative analysis of cinegraphs following exposure of embryos to a single teratogenic dose of caffeine (3.5 mg/egg) produced marked alterations in cardiac function when compared with chick Ringer's controls. Within 3 minutes after exposure to caffeine, dilation of the common ventricle and weak ventricular contractility were observed and persisted for 1 hour. Dose-response data and microcinematographic observations suggest that caffeine induced cardiac anomalies by a direct toxic effect on the embryo rather than by altering cardiac cell function. Our data also suggest that pathophysiologic changes in cardiac function may play an important role in the pathogenesis of caffeine-induced cardiac anomalies in the chick embryo.     

Craniofacial dermoids

Thirty-two patients with nasal dermal sinuses and cysts were treated during the 10-year period from 1978 to 1987. These patients presented with midline cysts (N = 18) or sinus ostia (N = 14). Only 6 of the 32 patients manifested intracranial extension (19 percent). All the patients with intracranial extension exhibited an intracranial mass on preoperative CT scans. Ten patients with no CT evidence of intracranial mass were noted to have only a fibrous cord extending to the base of the foramen cecum. In 4 of these 10 patients, craniotomy confirmed that there was no intracranial extension of the dermoid. Four other patients presented with sinus ostia at the base of the columella. None of these 4 patients had intracranial extension. Clinical examination and preoperative CT scans provide most of the information needed to determine the nature, course, and extent of these lesions.     

Craniofacial anomalies: from development to molecular pathogenesis

Advances in developmental biology combined with progress in human genetics are helping us decipher how the craniofacial region develops and how the consequences of misdirected development result in malformation. This review describes the molecular etiology of a number of craniofacial developmental anomalies. The more common craniofacial anomalies cleft lip and palate and craniosynostosis, as well as cleidocranial dysplasia, hemifacial microsomia, holoprosencephaly, enlarged parietal foramina, Treacher Collins syndrome and cherubism are discussed.     

Craniofacial and central nervous system malformations induced by triamcinolone acetonide in nonhuman primates: II. Craniofacial pathogenesis

This study further defines the craniofacial malformations induced by triamcinolone acetonide in the rhesus monkey. Ten timed-mated pregnant rhesus monkeys (Macaca mulatta) received intramuscular injections of 10 mg/kg TAC on days 23, 25, 27, 29, and 31 of gestation. Results of previous experiments with rhesus and bonnet monkeys and baboons indicated that specific craniofacial and brain malformations could be induced with TAC during this period of pregnancy (Hendrickx et al., '80). Stage-matched TAC-treated and control embryos (stages 17-18 and 22) and age-matched TAC-treated and control fetuses (50, 60, and 70 days gestation) were removed by hysterotomy. Stage 17-18 TAC embryos appeared grossly normal but histologic evaluation revealed a shortened anlage of the posterior cranial base. Stage 22 TAC embryos and all TAC fetuses exhibited craniofacial dysmorphia and encephalocele. The developing sphenoid was the earliest affected and most severely malformed bone. Its defects included reduced anterioposterior and transverse dimensions, reduced orbitosphenoid and alisphenoid, abnormal pituitary fossa, and reduced dorsum and tuberculum sellae. In addition, shortening of the posterior cranial base and decreased cranial base angle was a consistent finding in the treated embryos and fetuses. Decreased ossification and remodeling in the facial bones and abnormal position due to the malformed sphenoid occurred.     

Craniofacial anomalies in twins

Studies of twins provide insight into the relative contribution of genetic and environmental factors in the causality of structural anomalies. Thirty-five affected twin pairs were identified from a group of 1114 patients with congenital craniofacial deformities evaluated from 1972 to 1989. Forty-three of these 70 twins exhibited one or more craniofacial anomalies; these were analyzed for dysmorphic characteristics, zygosity, concordance, and family history. The anomalies were categorized into two groups: malformations and deformations. The malformations (n = 36) included hemifacial microsomia (n = 10), cleft lip and palate (n = 8), cleft palate (n = 4), rare facial cleft (n = 2), craniosynostosis (n = 2), Binder syndrome (n = 2), Treacher Collins syndrome (n = 2), craniopagus (n = 2), CHARGE association (n = 1), frontonasal dysplasia (n = 2), and constricted ears (n = 1). The deformations (n = 7) included plagiocephaly (n = 5), hemifacial hypoplasia (n = 1), and micrognathia (n = 1). Twenty-one monozygotic and 14 dizygotic twin pairs were identified. The concordance rate was 33 percent for monozygotic twins and 7 percent for dizygotic twins.(ABSTRACT TRUNCATED AT 250 WORDS)     

Craniofacial biology: Animal surgical experimentation and clinical practice

Studies are presented on the growth of the mandible in the pig, growth of the frontonasal suture and snout in the rabbit, and the development of the face and jaws in a human patient with anodontia. Growth of the snout after extirpation of the frontonasal suture is contrasted with its growth following resection of the cartilaginous nasal septum. The results of the studies have clinical applications in surgery and dentistry.     

Craniofacial distraction osteogenesis: a review of 3278 cases

The nascent field of craniofacial distraction osteogenesis has not yet been subjected to a rigorous evaluation of techniques and outcomes. Consequently, many of the standard approaches to distraction have been borrowed from the experience with long bones in orthopedic surgery. The ideal "latency period" of neutral fixation, rate and rhythm of distraction, and consolidation period have not yet been determined for the human facial skeleton. In addition, because the individual craniofacial surgeon's experience with distraction has generally been small, outcomes and meaningful complication rates have not yet been published.In this study, a four-page questionnaire was sent to 2476 craniofacial and oral/maxillofacial surgeons throughout the world, asking about their experiences with distraction osteogenesis. Information about the types of cases, indications for surgery, surgical techniques, postoperative management, outcomes, and complications were tabulated. Of 274 respondents (response rate, 11.4 percent), 148 indicated that they used distraction in their surgical practice. One hundred forty-five completed surveys were entered into a database that provided information about 3278 craniofacial distraction cases. Statistical analyses were performed comparing the rates of premature consolidation, fibrous nonunion, and nerve injury, on the basis of the use of a latency period and different rates and rhythms of distraction. In addition, the rates of all complications were determined and compared on the basis of the number of distraction cases performed per surgeon.The results of the study clearly show a wide variation in the surgical practice of craniofacial distraction osteogenesis. Although the cumulative complication rate was found to be 35.6 percent, there is a pronounced learning curve, with far fewer complications occurring among more experienced surgeons (p < 0.001). The presence of inferior alveolar nerve injury as a result of mandibular distraction was much lower for respondents whose distraction regimens consisted of no more than 1 mm of distraction per day (19.5 percent versus 2.4 percent; p < 0.001). No evidence was found to support the use of a latency period or to divide the daily distraction regimen into more than one session per day. Conclusions could not be drawn from this study regarding the length of the consolidation period. Overall, the surgeon-reported outcomes are comparable with those published for other craniofacial procedures, despite the higher incidence of complications.Although conclusions made on the basis of a subjective questionnaire need to be interpreted cautiously, this study has strength in the large numbers of cases reviewed. Because of the anonymity of responses, it has been assumed that surgeons who responded to the survey reported accurate numbers of complications and successful outcomes. Finally, additional clinical and animal studies that will be of benefit in advancing the field of craniofacial distraction osteogenesis are outlined.     

Craniofacial Dermoid Cysts: Histological Analysis and Inter-site Comparison

Introduction: Dermoid cysts are common, benign, embryologically derived soft tissue cysts that can arise at a variety of craniofacial sites. It is not known whether specific histological variations exist between the different craniofacial sites. This study aims to establish whether inter-site histologic differences exist between periorbital, nasal, scalp, and postauricular dermoid cysts and analyze these in context of their distinct embryological origin and varied clinical presentation.Methods: A retrospective review of craniofacial dermoid cysts was performed. Using light microscopy with hematoxylin and eosin staining, histological appearance was directly compared between craniofacial sites.Results: All (n = 16) cysts contained keratinizing, stratified squamous epithelial lining, intraluminal keratin, and hair. Sebaceous glands were commonly present (n = 13). Eccrine (sweat) glands were less common (n = 3). Structures of mesodermal origin were seen in three periorbital cysts. Only the six ruptured cysts showed evidence of inflammation.Conclusions: Histological properties of dermoid cysts are conserved between craniofacial sites (periorbital, nasal, scalp, and postauricular). This reflects the consistency of ectodermal inclusion during early embryological development, which is independent of specific craniofacial site or surrounding anatomical structures.