Maxillary volume growth in childhood.

Nasomaxillary abnormalities in form, position, and development in children are often prominent features of craniosynostosis, and in particular, craniofacial dysostosis. While attempting to quantitatively assess the volumetric maxillary deficiency in these patients, it became apparent that there was no "normal" reference range for maxillary volumes throughout childhood that could be used for comparison. The aim of this study was to generate a model for measuring maxillary volume and subsequent changes throughout childhood. The technique of segmentation was applied to magnetic resonance images obtained in 55 healthy children (30 boys, 25 girls), aged 1 month to 184 months (15.33 years). Maxillary volumes were plotted against age for boys and girls to create a model for normal maxillary growth during the first 15 years of life. Maxillary volumes were larger in boys at all ages. However, the pattern of maxillary growth in boys and girls was similar and could be divided into three periods, each lasting approximately 5 years. During the first 5 years of life, there is a steady increase in maxillary volume, at the end of which the maxilla has reached 53 percent of the volume recorded at 15 years. There is an accelerated rate of growth between 5 and 11 years, which corresponds to the development and eruption of the permanent dentition. Thereafter, until the age of 15 years, the rate of growth of the maxilla plateaus. Maxillary volume in the first 12 months of life is, on average, 29 cm3 in boys and 25 cm3 in girls. By 15 years of age, it has increased to an average of 73.0 cm3 in boys and 59.4 cm3 in girls (an increase by a factor of 2.5 in boys and 2.4 in girls). The difference between the two sexes is statistically significant for the entire series (boys: mean maxillary volume = 56.55 cm3, SD = 24.61; girls: mean maxillary volume = 40.68, SD = 17.69, p = 0.009, one-way analysis of variance).

Maxillary volume growth in craniosynostosis.

Craniosynostosis, and in particular, craniofacial dysostosis, exhibits abnormalities of the nasomaxillary complex in form, position, and development. The aim of this study was to quantitatively assess the volumetric maxillary abnormality in patients at the time of initial diagnosis of craniosynostosis and to make comparisons with a "normal" reference range for maxillary volumes throughout childhood. The technique of segmentation was applied to preoperative computed tomographic head scans obtained in 31 children (14 boys, 17 girls), between 1 and 34 months of age (mean, 11.06 months), who underwent cranial expansion surgery for craniosynostosis affecting the coronal suture complex. Maxillary volumes were plotted against age for the first 3 years of life and were compared with a healthy population. There was no statistical difference between the two sexes for mean maxillary volume. The mean maxillary volumes for the entire group were statistically smaller than the norm (p = 0.046, linear regression with age as a covariable), but there was no statistical difference among the four different groups of coronal synostosis (unilateral coronal, nonsyndromic bilateral coronal, nonsyndromic complex pansynostosis, syndromic bilateral coronal synostosis) (p = 0.407, one-way analysis of variance). On graphic data analysis, the maxillary volume was smaller than the norm in craniosynostotic children who presented in the first few months of life. However, by 7 months of age in nonsyndromic bilateral coronal synostosis and by 17 months of age in syndromic bilateral coronal synostosis, the maxillary volumes had increased toward the norm. This implies that the effect of the craniosynostotic process on the midface structures is present from birth and parallels the effect on the cranial vault sutures.

Ventricular volume change in childhood.

OBJECT: The aim of this study was to construct a model of age-related changes in ventricular volume in a group of normal children ages 1 month to 15 years, which could be used for comparative studies of cerebrospinal fluid circulation disorders and cerebral atrophy developmental syndromes. METHODS: A magnetic resonance imaging-based segmentation technique was used to measure ventricular volumes in normal children; each volume was then plotted against the child's age. In addition, intracranial volumes were measured and the ratio of ventricular to intracranial volume was calculated and plotted against age. The study group included 71 normal children, 39 boys and 32 girls, whose ages ranged from 1 month to 15.3 years (mean 84.9 months, median 79 months). The mean ventricular volume was 21.3 cm3 for the whole group, 22.7 cm3 in boys and 19.6 cm3 in girls (p = 0.062, according to t-tests). The mean ventricular volume at 12 months for the whole group was 17 cm3 (20 cm3 in boys and 15 cm3 in girls), representing 65% of the volume achieved by 15 years of age (87% in boys and 53% in girls). The volume increased by a factor of 1.53, to 26 cm3 (23 cm3 in males and 28 cm3 in females, increase factors of 1.15 and 1.86, respectively) at 15 years of age. The change in ventricular volume with age is not linear, but follows a segmental pattern. These age periods were defined as: 0 to 3, 4 to 6, 7 to 10, and 11 to 16 years. A statistical difference based on sex was only demonstrated in the first 6 years of life. The mean ventricular volume for the first 6-year period was 22.4 cm3 in boys and 15.7 cm3 in girls, and the difference was significant for the two sexes (linear regression analysis for age and sex, significant according to analysis of variance regression at 0.007, p = 0.108 for age, p = 0.012 for sex). Thereafter, there was no significant difference in ventricular volume between boys and girls with further growth. The ratio of ventricular volume to intracranial volume was 0.0175 for the whole group, 0.017 in boys and 0.018 in girls (p = 0.272, according to t-tests). At 12 months of age the ratio was 0.019; it stabilized to 0.015 at 8 years of age, and increased to 0.018 at 15 years of age. No statistical difference based on sex was demonstrated with growth. CONCLUSIONS: The ventricular volume in normal children increases with age by a factor of 1.5; the increase is in a nonlinear segmental pattern. Boys have significantly higher ventricular volumes only in the first 6 years of life. The ventricular/intracranial volume ratio remains stable throughout childhood.

Normal changes in orbital volume during childhood.

OBJECT: The aim of this study was to construct a model of changes in orbital volume that occur throughout childhood from the age of 1 month to 15 years, which could be used for comparative studies of disease states affecting orbital growth. METHODS: Using the procedure of segmentation on magnetic resonance images obtained in 67 healthy children, orbital volume was measured and plotted against age. During the first few months of life left orbital volume is on average 15 cm3 in male and 13 cm3 in female infants; these volumes increase to 26 cm3 and 24 cm3, respectively, by the time the child reaches 15 years of age. During the first few months of life right orbital volume is on average 16 cm3 in male and 13 cm3 in female infants; these volumes increase to 27 cm3 and 25 cm3, respectively, by the time the child is 15 years old. This represents an overall increase in orbital volume by a factor of 1.7 in boys and 1.8 in girls. By the time the child has reached 5 years of age, the orbital volume for both right and left sides has reached on average 77% of the volume seen at 15 years in both sexes. The differences between the two sides are not statistically significant for either sex. The change in orbital volume that is associated with age in general displays a linear pattern. Throughout childhood, orbital volumes are larger in boys than in girls, but share a similar growth pattern. The difference between the two sexes tends toward statistical significance during the first 5 years of life (left orbit p = 0.1, right orbit p = 0.04). CONCLUSIONS: During early childhood, orbital volume increases in a linear fashion, achieving a significant proportion of its final growth by the time the child is 5 years old.

Changes in orbital volume during childhood in cases of craniosynostosis.

OBJECT: Controversy remains concerning the timing of frontoorbital advancement (FOA) surgery performed for craniosynostosis. Reduced orbital volume and degree of exorbitism are often cited as reasons for early surgical intervention. To date, however, little attention has been given to orbital volume and its changes during the first few years of life as an indicator of orbital growth in children with craniosynostosis. Knowledge of orbital volume and growth patterns in individuals with craniosynostosis and those with normal cranial structures will enable surgeons to refine both the type and timing of surgical intervention required, thus obtaining the optimum outcome for their patients. METHODS: Using the procedure of segmentation, orbital volumes in 50 children with various forms of craniosynostosis were measured on preoperative computerized tomography scans. Changes in average volume that occur with increasing age were calculated and compared with a model of normal orbital volume growth. At presentation the children with craniosynostosis ranged in age from 1 to 29 months, with 82% of them within the 1st year of life. Several interesting observations emerged from this study. Excluding patients with unilateral coronal synostosis, there was no difference between orbital volumes measured on the right and left sides, allowing mean orbital volume measurements to be used for comparative purposes. Although children with craniosynostosis begin life with significantly smaller orbital volumes, overall normal mean volumes for both sexes are attained by 13 months of age, with volumes approaching normal by 6 months of age in male infants and by 8 months of age in female infants. Changes in orbital volume associated with age generally appear to be similar in most forms of craniosynostosis. There appears to be no significant difference in changes in orbital volume between children with syndromic or nonsyndromic forms of bicoronal synostosis. Orbital volume is significantly reduced on the ipsilateral affected side in cases of unicoronal synostosis in comparison with the contalateral side, but it is not significantly lower than that of normal. Finally, FOA surgery appears to restore normal growth of orbital volume. CONCLUSIONS: The results of this study indicate that the underlying mechanism leading to craniosynostosis and restriction of orbital volume "burns out" and begins to lose its major effects within the first few months of life. It would appear that FOA surgery should be delayed until the end of the second half of the 1st year of life, thus maximizing the effects of accelerated normal orbital growth and reducing the risks of relapse.