Craniofacial changes in unilateral microtia: II. An X-ray study

Roentgenocephalometry was used for studies into the extent and character of craniofacial changes in 45 adult males with unilateral (right-sided) microtia. Out of the whole complex of changes associated with this malformation the mandibular ramus showed the most marked involvement and represented the main cause of the accompanying deviations and asymmetries. On the average, the affected half of the face was compressed toward the level of the external auditory meatus both from above and below, but there was a marked variability in individual patients examined. No signs of asymmetry were disclosed in one third of the patients while severe asymmetry was present in one fifth of the patients. Facial hemihypoplasia exerted no substantial influence on the facial profile (when no retrusion of the lower jaw was present) on the sagittal maxillomandibular relations or on the occlusion of incisors, while in transverse direction a laterosuperior deviation of the mandible towards the affected side was clearly visible. A branchiogenic malformation affected the neighboring structures, the cranial base (a more marked curving), frontonasal segment (septum and premaxillar deviation), and the neurocranium (posterior rotation of the cranial vault). The inner ear structures (semicircular canals) were affected only rarely (in 4% of patients). These findings complemented the results obtained in the first part of our study and confirmed the complex character of this inborn anomaly.     

Interrelations between the involvement of individual branchiogenic components in microtia

On the basis of cephalometric, roentgencephalometric, tomographic, and somatoscopic studies of 81 adult males with unilateral microtia, investigations were carried out into the interrelation between the degree of involvement of the outer and middle ear and of the face; between the degree of mutual involvement of individual facial structures; and between the malformation of these structures and the degree of outer and middle ear anomalies. A significant relationship between the extent of damage to the main branchiogenic components (outer ear-middle ear-face) was found exclusively in individuals with highly severe or with very slight involvement. Therefore, the correlation coefficients were not characteristic for the predominant majority of our patients and their values were influenced by the frequency of marginal variants of the anomaly within the series. The calculations of the correlation coefficients for the whole variation range of the anomaly thus were meaningless. This knowledge could have general repercussions. Slight interrelations among the degrees of damage of certain facial structures showed at the same time the individual variability of facial configuration within this group of anomalies. Our findings were in good agreement with the experimentally documented hypothesis on the hematogenic origin of branchiogenic malformations and with the assumption based on this hypothesis. Facial asymmetry represents an important prognostic sign for the assessment of the extent of middle ear damage.     

Asymmetric vault modification in Hopi crania

Cradleboarding was practiced by numerous prehistoric and historic populations, including the Hopi. In this group, one result of cra-dleboarding was bilateral or asymmetric flattening of the posterior occipital. We test whether cradleboarding had significant effects on the morphology of the cranial vault, cranial base, and face. Additionally, we examine associations between direction of flattening and asymmetric craniofacial growth. A skeletal sample of Hopi from the Old Walpi site includes both nonmodified (N = 43) and modified individuals (N = 39). Three-dimensional coordinates of 53 landmarks were obtained using a diagraph. Thirty-six landmarks were used to define nine finite elements in the cranial vault, cranial base, and face. Finite element scaling was used to compare average nonmodified individuals, with averages of bilaterally, right, and left modified individuals. The significance of variation among “treatment” groups was evaluated using a bootstrap test. Pearson product-moment correlations test the association of asymmetry with direction of modification. Hopi cradleboarding has a significant effect on growth of the cranial vault, but does not affect morphology of the cranial base or face. Bilateral flattening of the cranial vault leads to decreased length and increased width of the cranial vault. Flattening of the right or left cranial vault results in ipsilaterally decreased length and width coupled with a corresponding increased length and width on the contralateral side of the cranial vault. There is a significant correlation of size asymmetry with direction of modification in the cranial vault, but not with size or shape change in the cranial base or face. © 1995 Wiley-Liss, Inc.     

Effects of annular cranial vault modification on the cranial base and face

Artificial modification of the cranial vault was practiced by a number of prehistoric and protohistoric populations, frequently during an infant's first year of life. We test the hypothesis that, in addition to its direct effects on the cranial vault, annular cranial vault modification has a significant indirect effect on cranial base and facial morphology. Two skeletal series from the Pacific Northwest Coast, which include both nonmodified and modified crania, were used: the Kwakiutl (62 nonmodified, 45 modified) and Nootka (28 nonmodified, 20 modified). Three-dimensional coordinates of 53 landmarks were obtained using a diagraph, and 36 landmarks were used to define nine finite elements in the cranial vault, cranial base, and face. Finite element scaling was used to compare average nonmodified and average modified crania, and the significance of the results were evaluated using a bootstrap test. Annular modification of the cranial vault produces significant effects on the morphology of the cranial base and face. Annular modification in the Kwakiutl resulted in restrictions of the cranial vault in the medial-lateral and superior-inferior dimensions and an increase in anterior-posterior growth. Similar dimensional changes are observed in the cranial base. The Kwakiutl face is increased anterior-posteriorly and reduced anterior-laterally to posterior-medially. Similar effects of modification are observed in the Nootka cranial vault and cranial base, though not in the face. These results demonstrate the developmental interdependence of the cranial vault, cranial base, and face. © 1993 Wiley-Liss, Inc.     

Effects of fronto-occipital artificial cranial vault modification on the cranial base and face.

Artificial reshaping of the cranial vault has been practiced by many human groups and provides a natural experiment in which the relationships of neurocranial, cranial base, and facial growth can be investigated. We test the hypothesis that fronto-occipital artificial reshaping of the neurocranial vault results in specific changes in the cranial base and face. Fronto-occipital reshaping results from the application of pads or a cradle board which constrains cranial vault growth, limiting growth between the frontal and occipital and allowing compensatory growth of the parietals in a mediolateral direction. Two skeletal series including both normal and artificially modified crania are analyzed, a prehistoric Peruvian Ancon sample (47 normal, 64 modified crania) and a Songish Indian sample from British Columbia (6 normal, 4 modified). Three-dimensional coordinates of 53 landmarks were measured with a diagraph and used to form 9 finite elements as a prelude to finite element scaling analysis. Finite element scaling was used to compare average normal and modified crania and the results were evaluated for statistical significance using a bootstrap test. Fronto-occipitally reshaped Ancon crania are significantly different from normal in the vault, cranial base, and face. The vault is compressed along an anterior-superior to posterior-inferior axis and expanded along a mediolateral axis in modified individuals. The cranial base is wider and shallower in the modified crania and the face is foreshortened and wider with the anterior orbital rim moving inferior and posterior towards the cranial base. The Songish crania display a different modification of the vault and face, indicating that important differences may exist in the morphological effects of fronto-occipital reshaping from one group to another.     

Vertical growth of the anterior face and cranium in inner city Negro children

A longitudinal cephalometric study was conducted on the vertical growth of the cranium and anterior face on 60 inner city American Negro children, an equal number of boys and girls from four to nine years. Three vertical measurements were used for the purpose of this study. The head height was measured from sellion to bregma, bony nasal height from nasion to anterior nasal spine, and lower facial height from anterior nasal spine and lower facial height from anterior nasal spine to menton. The data were analyzed at annual ages and observations made relative to the growth trends. The findings of this study were compared with those on Caucasian children. No significant statistical difference was found in the mean head (cranial vault) height between the Negro and Caucasian children. The mean bony nasal height expressed as a percentage of subnasal height was found to be less in the Negro children. The difference decreased with age. The annual increment of growth in head height was greater from four to seven years than from seven to nine years. The findings are considered to imply that severe malnutrition may influence child growth.     

Maxillary changes and occlusal traits in crania with artificial fronto-occipital deformation

Artificial fronto-occipital deformation of the cranial vault was typical of pre-Columbian cultures in the central Andean coastal regions. We have studied the influence of this deformation on maxillary and mandibular morphology. Measurements were performed on 86 adult Ancon skulls with anteroposterior deformation. Undeformed skulls from the area of Makatampu (n = 52) were used as the control group. To explore the influence of the deformity on occlusion, the skulls were categorized using the Angle classification and the alignment of the interincisor midline. In the group of deformed skulls, there was an increase in lateral growth of the vault and of the base of the skull (P < 0.001), giving rise to a greater interpterygoid width of the maxilla (P < 0.001), and an increase in the transverse diameter of the palatal vault. The mandible presented an increase in the length of the rami (P < 0.001) and in the intercondylar width, with no alteration of mandibular length. The deformed skulls had normal (class I) occlusion, with no displacement of the midline. The difference in the asymmetry index between the two groups was not statistically significant. Artificial fronto-occipital deformation of the cranial vault provoked compensatory lateral expansion of the base that was correlated with the transverse development of the maxilla and mandible. Occlusion and sagittal intermaxillary position were not affected by the cranial deformity. These results provide evidence of the integration between the neurocranium and the viscerocranium in craniofacial development, and support the hypothesis of a compensatory effect of function.     

Craniofacial deformity in patients with uncorrected congenital muscular torticollis: an assessment from three-dimensional computed tomography imaging

Congenital muscular torticollis is caused by idiopathic fibrosis of the sternocleidomastoid muscle that restricts movement and pulls the head toward the involved side. Deformation of the craniofacial skeleton will develop if the restriction is not released and result in aesthetic and functional problems. The purpose of this study was to use three-dimensional computed tomography imaging for qualitative and quantitative evaluation of the craniofacial deformity in a series of patients with uncorrected congenital muscular torticollis, and to assess age as a precipitating factor for severity of the deformity. A total of 14 patients from 1 month to 24 years of age were included. The skull images were rotated into standard orientation and reconfigured for evaluation of the cranium, endocranial base, and facial skeletal structures. The midlines of cranial base and facial bone, angle of midline deviation, width of each hemicranium and hemiface, and the orbital index were defined and measured. The results showed that the cranium and cranial base deformation took place as early as in infant stage, with the most prominent change occurring in the posterior cranial fossa. Facial bone asymmetry started to appear after 5 years of age, at which time the mandibular and occlusal abnormalities were observed. The deformity of the orbits and maxilla occurred at an older age, characterized by the deviation and decreased vertical height on the affected side. The severity of the observed deformities increased with age. The angle of midline deviation was 2.48 +/- 1.68 degrees in the cranial base and 3.26 +/- 3.28 degrees on the facial bone. Both of the midline deviations were significantly correlated with age. Compared with the contralateral side, the width of the ipsilateral posterior hemicranium was longer (54.36 +/- 6.72 mm versus 50.81 +/- 6.55 mm), and the width of the ipsilateral lower hemiface was shorter (35.30 +/- 7.27 mm versus 43.49 +/- 11.34 mm). Both differences were statistically significant. Measurement of the orbital index demonstrated a significantly flatter orbit on the ipsilateral side (89.48 +/- 0.11 versus 92.74 +/- 0.08). This study showed that the cranium and cranial base deformity occurred early in patients with uncorrected torticollis, while the facial bone deformity occurred in childhood stage. The cranial and facial deformity became more severe with age. Early release of the muscle restriction is advised to prevent craniofacial deformation.     

Craniofacial suture stenosis: morphologic effects

Craniofacial anomalies, such as Apert's and Crouzon's syndromes, are presumed to be related to premature growth arrest of cranial base growth sites. However, premature growth arrest at cranial vault sutures in animals appears to play a causative role in the development of cranial deformities characteristic of single-suture, or simple, craniosynostosis in humans. To study the possible causative role of cranial vault and other (interface) suture stenoses on the development of craniofacial deformity, a vault suture and an interface suture between the cranial vault and facial skeleton were simultaneously immobilized. Thirty-one New Zealand White rabbits at 9 days of age underwent implantation of dental amalgam growth markers adjacent to cranial vault and facial sutures. In the experimental group (n = 15), methylcyanoacrylate adhesive was applied over the coronal (vault) and frontonasal (interface suture between vault and facial skeleton) sutures to immobilize them. The remaining 16 animals served as sham-treated controls. All animals underwent serial radiographic cephalometry to document growth effects in the cranial vault, cranial base, and facial skeleton. Application of adhesive resulted in statistically significant (p less than 0.05) reduction in growth at the coronal and frontonasal sutures. This was accompanied by an overall significant reduction in neurocranial vault length during the first 30 days of development.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cranial base and jaw relationship

The lateral skull radiographs of 124 boys aged approximately 10 years divided equally between the four angle classes were digitized in an effort to establish the relationship between cranial base size and shape and jaw relationship. Comparison of the means for occlusal groups showed a trend from class II to class III as cranial base dimensions and angle decreased. The condyle was also more distally positioned with respect to nasion, point A and the Pterygomaxillary vertical in the class II groups. Cranial base length correlated strongly with maxillary length but weakly with mandibular length. Nevertheless, the size of the maxilla did not influence its prognathism. The cranial base angle was strongly correlated (-0.7) with angle sella-nasion-point B. It is concluded that cranial base size and shape influence mandibular prognathism by determining the anteroposterior position of the condyle relative to the facial profile.     

Facial asymmetry: three-dimensional analysis using laser surface scanning

This study evaluates six different techniques with respect to their ability to quantitatively describe facial asymmetry in three dimensions. Three-dimensional facial images were acquired using a Cyberware 3030RGB laser surface scanner. Image processing was performed on a Silicon Graphics Indigo computer workstation. The following techniques for facial asymmetry analysis were developed: asymmetry in the location of anthropometric landmarks, Euclidean distance matrix analysis (EDMA), scalar measurement of the lower ciliary margin and palpebral fissure area, clearance vector mapping, and determination of the volume of asymmetry. Techniques were applied and validated in three anthropometric models: a perfectly symmetrical plastic head model and a plaster head model with and without a unilateral cheek augmentation. In each of the anthropometric test models, each analytical technique was validated by means of static anthropometric facial models and was evaluated for intraobserver and interobserver reliability. Asymmetries in the location of anthropometric landmarks can be accurately determined to within 2 mm in x, y, and z directions of the Cartesian space. EDMA is a useful technique in describing both size and shape changes of discrete areas of the face. Measurement of the lower ciliary margin and palpebral fissure area is reliable. Clearance vector mapping is especially useful in quantifying facial surface asymmetries in facial areas where anthropometric landmarks are scarce. Volume of asymmetry is potentially useful in those patients for whom the use of injections or implants of known volume may be helpful in correcting unilateral facial deficiencies.     

华北人欧洲人和澳洲土著人的头骨厚度

The thickness of the cranial vault at the midline on the mid-frontal squama, pre-bregmatic einence, frontal at bregma, parietal at vertex, occipital at lambda and the external occipita1 protuberance was recorded in 40 male and 7 female Northern Chinese crania, 47 male and 52 female Australian Aboriginal crania and 13 male European crania using specially nodified vernier calipers. Comparison of vault thickness data obtained through direct measurement with those obtained fron lateral radiographs indicated that direct measurenent provided consistently more accurate results.
Male and fermale samples were processed separately so that the extent of sexbased variation could be examined.Student's t test was used to compare the sample means and the percentage of sexual dimorphism for each dimension was calculated according to Garn et al, (1964).The possibility of an allometric association between the thickness of the bones within the cranial vault, size of the cranial vault and stature was examined using Spearman's rank correlation coefficient and the Australian Aboriginal sample.
All but one of the mean thickness dimensions in the Australian Aboriginal male sample is significantly greater than the Northern Chinese and European means. The female results support those obtained with the males.In both males and females thickness at the external occipital protuberance, in all of the populations examined,did not correlate highly with that obtained from other parts of the cranial vault.This reflects the high degree of morphological variation in the position of the internal occipital protuberance and its influence on cranial vault thickness dimensions recorded at the external occipital protuberance.The European and Northern Chinese samples have similar cranial vault thickness dimensions. The Spearman's rank correlation coefficient matrix scores provide sone support for a biological association between vault thickness and overall cranial size. However, there appears to be little support for an association between stature and cranial vault thickness. The difference between the male and female mean vault thickness dimensions were significant at bregma, vertex and the external occipital protuberance in Australian Aboriginals and lambda and the external occipital protuberance in Northern Chinese. Some caution is needed in the interpretation of the Northern Chinese female data as the sample is extremely small.
Evidence of trauma, supressed fractures, is extremely common on the vaults of Australian Aboriginal crania from southern and central Australia. Traditionally Australian Aboriginals, males and females, involved in agressive dispute will use a substantial wooden implement and strike to the head of thir opponent(Meggitt 1962).The injuries that result from this are more common in females than in male. This form of social interaction must have rigorously selected against those individuals with thinner bones in their cranial vaults. To a large degree this may explain the greatly thickened vaults in Australian Aboriginals relative to Europeans and Northern Chines.This may also provide a clue to the factors resulting in the development of marked cranial vault thickness in Homo erectus.
     

Roentgencephalometric study of cranial interrelations

Lateral X-ray films of the skull obtained in 50 normal adult males were used for studies of correlations between 26 characteristics of the size, shape, and position of the face and nine characteristics of the neurocranium in all mutual combinations. The results disclosed that the relations between individual cranial components were regulated by certain principles. The correlations between size dimensions were mostly slight; a closer relationship showed some characteristics of the shape and position. The most important variable exerting an effect on the configuration of the skull as a whole represented the angle of the cranial base which produced the rotation of the neurocranium and the face and thus acted on a series of other correlations. Of some importance as well was the length of the mandibular ramus acting on the shape and position of the lower jaw and on the vertical maxillomandibular relations. The close relationship between the anteroposterior position of both jaws was due to compensation mechanisms rather than to the identical size of both jaws. On normalization of the disturbed saggital jaw relations, the dentoalveolar components of both jaws as well as the subalveolar component of the mandible participated equally. In vertical direction the lower face showed a certain developmental independence. The discussed interrelations formed the basis for studies of the mechanisms regulating the intracranial development and the changes occurring in various anomalies, as well as for understanding the compensation and adaptation abilities of individual cranial components.     

Exencephaly and axial skeletal dysmorphogenesis induced by maternal exposure to cadmium in the mouse

To investigate the axial skeletal dysmorphogenesis associated with exencephaly and facial abnormalities, two doses of cadmium chloride (4 mg/kg and 6 mg/kg) were administered subcutaneously to MF1 mice on day 7 of gestation (sperm-positive day = day 0). Fetuses were collected on day 18. Gross examination revealed a very high incidence of cranioschisis aperta with exencephaly, maxillary and mandibular hypoplasia, low-set microtia, edema, and growth retardation of fetuses in both treatment groups. Alizarin red S-stained and cleared skeletal preparations of these embryos revealed hypoplasia of the premaxilla, maxilla, nasal bone, zygoma, and mandible of the facial skeleton. The orbital plate represented the frontal bone. The vault of the skull was conspicuously absent. In cranioschisis, the exoccipitals had splayed and fused with the atlas. The basicranial bones were hypoplastic and crowded, thus reducing the cranial cavity. The vertebral bodies were more affected than the arches. Hemivertebrae and longitudinal fusion of centra and arches were also noted. The ribs were usually rudimentary. Agenesis, fusion, and forking of ribs were frequently observed. The sternebrae were rudimentary, bipartite, or longitudinally fused. These data clearly establish the association between neural tube and axial mesodermal abnormalities and emphasize the interdependence of the neurectoderm and mesoderm in normal morphogenesis.     

A cephalometric study in Rubinstein-Taybi syndrome

A roentgencephalometric study to compare the facial morphology of 18 individuals affected with Rubinstein-Taybi syndrome and 25 of their parents was performed. The main findings in the affected individuals were shortening of facial height and depth, cranial base length, a marked decrease in size of the mandible, and a steep cranial base. A change with age was found for some dimensions. The pattern variability indices were high, indicating an abnormal craniofacial profile. The correlations between most patients were high, although this was less expressed for the younger patients. The parents had a normal pattern profile and pattern profile variability indices. The correlation between parents and their affected children was low. This study suggests that pattern profile analysis of cephalometric measurements may be a useful diagnostic tool in Rubinstein-Taybi syndrome. However, comparable studies of large groups of patients, especially of a younger age, are needed for further ascertainment of normal values in individuals with Rubinstein-Taybi syndrome at different stages of facial development.     

Correction of unilateral coronal synostosis leads to resolution of mandibular asymmetry in rabbits

Mandibular dysmorphology in unilateral coronal synostosis has been recognized clinically. In patients with unilateral coronal synostosis, the chin point deviates away from the affected side. To investigate whether this mandibular asymmetry resolves after correction of unilateral coronal synostosis, familial nonsyndromic rabbits were used. Rabbits with unilateral coronal synostosis that underwent "correction" with resection of the affected suture were compared with "uncorrected" rabbits with unilateral coronal synostosis and normal, wild-type rabbits (n = 36; three equal groups of 12). Serial lateral cephalograms obtained at 10, 25, 42, and 84 days showed no asymmetries in wild-type rabbits and progressive asymmetries in the ramal height and mandibular length in uncorrected unilateral coronal synostosis rabbits. However, in corrected unilateral coronal synostosis rabbits, existing asymmetries at 10 and 25 days improved by 42 days and were not seen by maturity, at 84 days. In dry, mature, mandibular specimens, wild-type rabbits showed equal side-to-side measurements and uncorrected unilateral coronal synostosis rabbits showed the following on the affected side: longer ramal height (15 percent), shorter ramal width (13 percent), longer body height (10 percent), and shorter body width (13 percent). By contrast, the corrected unilateral coronal synostosis specimens showed no side-to-side differences in 10 of 11. There were no asymmetries in condylar shape or condylar volume in any of the three groups. Cranial base measurements showed asymmetries of the uncorrected unilateral coronal synostosis specimens that were consistent with an anteriorly positioned glenoid fossa on the affected side. However, only one of 11 corrected unilateral coronal synostosis specimens showed similar cranial base asymmetries. The data showed that mandibular asymmetries in nonsyndromic, familial rabbits with unilateral coronal synostosis are progressive with growth but improve after correction of synostosis.     

Experimental unilateral coronal synostosis in rabbits

Immobilization of the coronal suture was produced unilaterally in 9-day-old rabbits to determine its effect on subsequent craniofacial development. The suture was immobilized unilaterally by the topical application of methylcyanoacrylate adhesive. Subsequent growth effects on the cranial vault, base, and facial skeleton were assessed by serial radiographic cephalometry. Unilateral coronal suture immobilization resulted in significantly decreased bone growth at the coronal suture (mean 0.95 mm +/- 0.35 SE) when compared to sham-treated control animals (mean 5.06 mm +/- 0.20 SE). Frontonasal suture bone growth contralateral to the immobilized half of the coronal suture, however, was significantly increased. The anterior cranial base became significantly shortened, and orbital asymmetry developed. The pattern of induced abnormalities simulates unilateral coronal synostosis in humans.     

13—18岁正常人上、中面部对称性生长发育的纵向研究

本文运用13— 18岁正常纯纵向样本资料 ,头颅定位后前位 X线头影测量法 ,分析正常人上、中面部的对称性与变异 ,探讨其随生长发育的变化趋势 ,为客观区分对称性的正常变异和不对称畸形提供依据。结果表明 :正常人上、中面部骨骼存在对称性的正常变异 ,其范围在13—18岁保持稳定 ,水平向小于8% ,垂直向不超过9mm;在其相对于颅底的位置关系及其骨骼各对应部位之间 ,有较好对称性 ;面部骨骼的生长发育具有潜在的优势特点。     

Cranial capacity/cranial base relationships and prediction of vault form: A canonical correlation analysis

Canonical correlation analysis was used to test an hypothesized morphological relationship between vault form and cranial capacity relative to length of the chondrocranium. Ninety-five adult male Czech skulls were measured for vault form expressed as length, width and height of the brain case; the chondrocranium was represented by nasion-basion and basion-opisthion lengths. In terms of explained variation, the first and most important dimension of covariation between vault and chondrocranial variables was size. The second most significant dimension of covariation expressed the hypothesized shape relationships—i.e., overall size being equal, the shorter the chondrocranial base relative to cranial capacity, the shorter and wider the vault. Furthermore, the competing hypothesis that vault form is determined by facial length proved untenable since facial length was predictive of vault shape only when measured as prosthion-basion, a measure that incorporates basal length. When corrected for basal length, facial length is unrelated to vault form. The results are consistent with the assumption that phylogenetic and microevolutionary trends toward brachycephaly in man stem from changes in the relationship between two components of skull growth, the chondrocranial base and the brain.