Journal of craniofacial genetics and developmental biology. Supplement最新文献

Parents of children with right-sided cleft lip are more likely to be non-right-handed than parents of children with left-handed or bilateral cleft lip. The implications are discussed.

The area of palatal mucosa and the size of the maxillary arches were measured in a group of 30 newborn infants with unilateral clefts of the lip and palate. The overall size of the maxillary arch together with the arch width and arch height were also measured when the children had reached 5 years of age. For comparison purposes, a group of 30 newborn normal children and 30 normal 5-year-old children were similarly measured. The cleft children were found to have a mean deficiency of palatal mucosa of 16.41% at birth, although the overall size of their maxillary arches was 17.08% greater than normal. In the cleft cases there was no significant correlation between the area of palatal mucosa at birth and the overall size of the arch at 5 years of age. A significant correlation did exist between the overall size of the arch at birth and the overall size when the child was 5 years old. The significance of this and other findings is discussed.

Hemifacial microsomia (HFM) and the branchio-oto-renal syndrome (BOR) are both associated with malformations of the external ears; preauricular tags, pits, or sinuses; and conductive or mixed hearing loss. Other overlapping features have been described, including cervical appendages containing cartilage in HFM, and facial paresis in BOR; however, the significance of these findings has not been discussed by previous authors. The purpose of this paper is to describe four additional propositi with overlapping features of BOR and HFM. In two cases there is a positive family history of either first and second branchial arch anomalies or malformation of the kidney. Two cases appear to be sporadic. The overlapping clinical features suggest that in some families HFM may constitute a component toward the severe end of the spectrum of the autosomal dominant BOR syndrome. The empiric recurrence risk for HFM was 3% in one study. If our interpretation of these reported cases is correct, genetic recurrence risks for individuals in these families may fall in the range of an autosomal dominant condition. Since expression of both conditions varies widely, and minor manifestations may be overlooked, the importance of careful evaluation of first- and second-degree relatives is emphasized.

Newborn-CL/Fr mice have +/- 20% frequency of cleft lip with or without cleft palate (CLP) depending on environment. However, examination of early fetal development from days 12 to 15 disclosed an increased number of hematomas or fluid-filled blebs in the regions of maxillary process fusion. The earliest stages do not appear to involve the blood supply directly but separate the epithelium from underlying mesenchyme by clear blebs. Similar defects were found in untreated A/J mice. These findings suggest that osmotic and hemodynamic abnormalities may be part of the mechanism of cleft lip formation in these related strains and that these defects may result from a biochemical defect of the connective tissue matrix in regions of process fusion.

Human achondroplasia can be viewed as an experimental model for studying the effects of abnormal endochondral bone formation on the development of the skull as a whole. In this study, lateral cephalograms of 25 adult males and 26 adult females with achondroplasia were converted to a two-dimensional coordinate model of craniofacial morphology and analyzed using 66 linear, angular, and area variables. Lateral cephalograms of 951 normal adults were used for comparison. Two sample t-tests were used to compare achondroplastic cephalograms with normal cephalograms. Multivariate statistical analysis included Hotelling's T2 and discriminant function analysis. Selected variables were graphed as profile patterns in which mean values were expressed as standard deviation units (Z scores) relative to the norm. Finally, Calcomp plots were used for visual inspection and for comparison of the average cephalometric tracings of male and female achondroplastic subjects with normal male and female subjects, respectively. Significant findings in achondroplasia included enlarged calvaria, frontal bossing, large frontal sinuses, occipital prominence, normal anterior cranial base length, strikingly shortened posterior cranial base length, an acute cranial base angle, a short nasal bone that was deformed and depressed, short upper facial height, recessed maxilla, posterior tilt of the nasal floor, and a prognathic mandible that was anteriorly displaced but of normal size with a normal gonial angle and a high coronoid process. The finding of normal anterior cranial base length in achondroplastic subjects was surprising since the cranial base is preformed in cartilage and hypoplasia and shortening would be expected. Since the brain is enlarged in achondroplasia, the expanding frontal lobes may possibly influence the growth of the anterior cranial base, since it is known to follow a neural pattern of growth. Cribriform plate length was strikingly reduced, but anterior sphenoidal length was strikingly increased, compensating for the shortened cribriform plate length and suggesting that growth in the length of the anterior cranial base takes place primarily by adaptation at one site--namely, the sphenoethmoidal synchondrosis. Strikingly short posterior cranial base length was interpreted as resulting from hypoplasia of bone that is preformed in cartilage with possible early closure of the spheno-occipital synchondrosis. The exaggerated closure of the cranial base angle in achondroplasia may be related to an increased brain size and possibly earlier than normal closure of the intersphenoidal synchondrosis.(ABSTRACT TRUNCATED AT 400 WORDS)

Teratological experiments were made with a recessive mouse gene (cranioschisis) causing exencephaly and a semidominant gene (delayed splotch) causing spina bifida. In studies with the cranioschisis gene administration of warfarin and thyroxine resulted in frequencies of exencephaly significantly below that expected of a recessive trait, perhaps indicating selective elimination of abnormal conceptuses. Studies with the delayed splotch gene tested the hypothesis that offspring with a hereditary defect of neural-tube closure have other, unexpressed CNS defects, which may be elicited by teratological impulses. This proposition was decisively upheld by administering 5-bromo-2'-deoxyuridine, cadmium sulfate and retinoic acid, as these treatments all caused significantly greater frequencies of induced exencephaly in offspring with spina bifida than in their genetically normal littermates.

Objective quantitative methods for standardized reproducible descriptions of the findings of an examination are prerequisite for the optimal care of patients with congenital or acquired craniofacial anomalies. The present report gives a brief review of the development of roentgencephalometry with special emphasis on the infant roentgencephalometric techniques pioneered by Dr. Samuel Pruzansky. In addition, some of the significant findings that have emerged from the application of these techniques to patients with craniofacial anomalies are presented, again, with emphasis on the contributions made by Dr. Pruzansky and co-workers. Finally, perspectives for future clinical and research work within the field are outlined. These perspectives include improvement of cephalometric units for studies of patients with craniofacial anomalies; inclusion of additional cephalometric projections, especially in patients with craniofacial asymmetry; increased utilization of infant cephalometry; utilization of metallic implants in selected cases; greater utilization of computerized cephalometrics and multivariate statistics; and combined use of longitudinal cephalometric studies and various longitudinal physiological examinations, eg, electromyography, kinesiography, and air flow studies, in the individual patient.

Attainment of normal speech, facial and palatal development, and dental occlusion is possible without compromising one objective for another. Although speech development may benefit from early palatal closure, there are instances when cleft closure should be postponed to a later age to permit conservative palatal surgery. Increase in palatal size with the spontaneous narrowing of the cleft space can occur early, late, or not at all, and, in rare instances, the cleft may even widen. Nonphysiological surgery causes facial and palatal maldevelopment by extensive undermining and displacement of mucoperiosteum, fracture of bone, or destruction of blood supply. To avoid these consequences, timing of palatal closure should be related to the anatomical and functional assets in the individual and not determined by age alone. Serial studies of 36 unilateral (UCLP) and 29 bilateral (BCLP) cleft lip and palate cases with good speech demonstrated that conservative palatal surgery is conducive to good speech as well as palate and facial development. Speech appliances may be necessary as an interim device after 2 years of age.

Specific forms of ocular motor disturbances, such as Duane syndrome, occur with sufficient frequency in certain syndromes that the timing, location, and nature of the developmental disturbance may be established. The presence of this characteristic type of strabismus in a number of cases of hemifacial microsomia, especially the Goldenhar variants, may provide insight into the developmental disturbances of this large, complex group of patients. Evaluation of specific abnormalities of affected patients from the perspective of one discipline may further aid in the "lumping" or "splitting" process.