Craniofacial and Velopharyngeal Dimensions in Infants 0-12 Months: Between- and Within-Group Differences Based on Age and Sex

PURPOSE

The purpose of the present study is to (a) provide quantitative data on the growth of levator veli palatini (LVP), velopharyngeal (VP), and craniofacial dimensions in children under 12 months while controlling for corrected age and sex and (b) compare variability within age and sex groups.

METHOD

Magnetic resonance imaging scans of 75 infants between 0 and 12 months were measured and divided into four age groups. These data were obtained as part of a larger retrospective study. Following exclusion criteria, scans were analyzed, and dependent variables were obtained.

RESULTS

There was a statistically significant (p < .0001) difference between corrected age groups on LVP muscle, VP, and craniofacial variables while controlling for sex. Significant growth effects were observed for LVP length (p < .0001), extravelar length (p < .0001), intravelar length (p = .048), midline thickness (p = .0001), origin-origin distance (p < .0001), velar length (p < .0001), velar thickness (p = .003), nasion-sella turcica distance (p < .0001), sella turcica-basion distance (p < .0001), and hard palate length (p < .0001). Significant sex effects were observed for pharyngeal depth (p = .026) and effective VP ratio (p = .014). When age was treated as a continuous variable, similar results were observed for all variables except pharyngeal depth. Within-group comparisons revealed the most variability occurs between 3 and 5.99 months for LVP and craniofacial variables and between 9 and 11.99 months of age for VP variables. Male participants demonstrated greater variability than female participants.

CONCLUSIONS

Differences were observed in LVP, VP, and craniofacial variables in children under 12 months while controlling for sex. Males demonstrated larger values and greater variability for most variables.

Novel prediction models for pharyngeal-airway volume based on the cranial-base and midsagittal cross-sectional area of the airway in the pharyngeal region: A cephalometric and magnetic resonance imaging study

OBJECTIVE

The objective of the study was to elucidate the association between cranial base (Bjork-Jarabak analysis), midsagittal cross-sectional area of the airway in the pharyngeal region (MCSA-PR) data and pharyngeal-airway volume (PAV) and develop a model that could help clinicians predict PAV using two-dimensional (2D) data (Bjork polygon and MCSA-PR).

MATERIALS AND METHODS

Pre-treatment lateral cephalometric radiographs and magnetic resonance imaging (MRI) scans of 82 women were categorized into three anteroposterior skeletal groups based on ANB angle: Class I (n = 29), 1.5° ≤ ANB≤5.1°; Class II (n = 26), ANB >5.1°; Class III (n = 27), ANB <1.5°. The Bjork polygon, MCSA-PR data from cephalograms and PAV data from MRI scans were examined. Intergroup comparisons were performed using the Kruskal-Wallis test and one-way analysis of variance (ANOVA), with pairwise comparisons conducted using the Bonferroni-corrected Mann-Whitney U-test for the Kruskal-Wallis test and Bonferroni-corrected multiple comparison test for one-way ANOVA. Forward multiple linear regression was used to create model equations for predicting PAV.

RESULTS

MCSA-PR and anterior (N-S) and posterior (S-Ar) cranial-base lengths were positively correlated with the PAV. We developed four models; three operated at the group level, and one encompassed the entire sample. Notably, all models could effectively explain the variance in the PAV data. The model for the Class I group was the strongest (adjusted R2 = 0.77).

CONCLUSION

Our findings indicate the remarkable potential of the MCSA-PR, N-S and Bjork sum angles (BSA) as predictors of the PAV and the relevance of 2D cephalometric and cranial-base parameters in predicting the three-dimensional (3D) pharyngeal-airway size.

Comparison of the transverse cranial base dimension in different craniofacial skeletal relationships: A cone-beam computed tomography study

Background/purpose

In comparing the cranial base's size, most cephalometric studies focused on the length and angle in the anteroposterior direction. However, investigating the anterior, middle, and posterior cranial base's transverse dimensions is challenging. This study aimed to investigate the transverse dimensions of the cranial base in different craniofacial skeletal patterns and sexes using cone-beam computed tomography (CBCT).

Materials and methods

A total of 210 adults (105 males and 105 females), including three different skeletal relationships, were included in the study. The cranial base dimensions were measured on a three-dimensional image structure rendered by CBCT. Statistical methods included the Kappa statistic for analysis of consistency and reproducibility and the independent t-test for differences in cranial base dimensions between sexes. A general linear model (GLM) was used to compare the transverse size of the cranial base among skeletal Class I, II, and III groups. The Pearson correlation coefficient explored the correlation among the cranial base dimensions.

Results

The cranial base dimensions did not differ significantly between skeletal Class I, II, and III. The more prominent cranial base size was found in males than females, except for the crista galli length (CGL) and cribriform ethmoid plate width (CEPW). The cranial base dimensions did not differ significantly between different skeletal relationships. Most dimensions have significant correlations in the middle and the posterior cranial base.

Conclusion

The cranial base's transverse dimensions in Taiwanese adults show no significant differences between craniofacial skeletal relationships. In the middle and posterior cranial base, transverse measurements reveal significant sexual dimorphism.

Assessment and comparison of cranial base morphology in individuals with long face and short face

OBJECTIVES

The objectives of the study was to assess and compare the cranial base morphology in long face and short face.

METHODOLOGY

The study comprises 64 individuals (32 in each group). Group I consists of individual's with long face and group II comprises individuals with short face. Individuals were classified into groups with the help of lateral cephalometric parameters like Gonial Angle, Anterior facial height, Posterior facial height, Jarabak's Ratio, and Y-axis. Linear and angular measurement in the cranial base was taken.

RESULT

The results showed statistically significant difference in Sella-Nasion, Sella-Basion and Nasion-Sella-Basion between the two groups. Sella-Spinoethmoidal suture, Nasion-Spinoethmoidal suture, Spinoethmoidal suture-Sella-Basion, Frankfurt Horizontal-Sella-Nasion, Frankfurt horizontal-Sella-Basion, Frankfurt horizontal-Sella-Spinoethmoidal suture showed no statistically significant difference among the groups.

CONCLUSION

The study concluded that individuals with long face have a greater Sella-Nasion, Sella-Basion, Nasion-Sella-Basion compared to individuals with short face.

Cranial base measurements in different anteroposterior skeletal relationships using Bjork-Jarabak analysis

OBJECTIVES

To assess the linear and angular cranial base measurements (Bjork polygon) in different anteroposterior (AP) skeletal relationships using Bjork-Jarabak analysis.

MATERIALS AND METHODS

Pretreatment lateral cephalograms of 288 (146 women, 142 men, mean ages 21.24 ± 2.72 years and 22.94 ± 3.28 years, respectively) adult patients were divided into Class I, II, and III skeletal relationships according to their ANB angle. Linear and angular measurements of Bjork polygon were measured and compared among different skeletal relationships. Analysis of variance was performed to detect the differences among groups. Independent-sample t-test was used to detect differences between men and women.

RESULTS

The Class II skeletal relationship has a significantly larger saddle angle than Class III does (P < .05), whereas Class III has a significantly larger gonial angle than Class II does (P < .05). The articular angle and sum of Bjork polygon angles were not significantly different among groups (P > .05). Anterior (N-S) and posterior (S-Ar) cranial base lengths were similar in the different AP skeletal relationships (P > .05). The ramal height and body of the mandible length were significantly larger in Class III compared with Class I and II (P < .05). Women had a significantly larger articular angle than men did (P < .05), although men had significantly larger linear measurements of Bjork polygon than women did (P < .05).

CONCLUSIONS

The Class III skeletal relationship has a smaller saddle angle and larger mandibular length and gonial angle. Men have a larger cranial base and mandibular linear measurements and a smaller articular angle compared with women.

Morphometric evaluation of cranial base and sella turcica in patients with bilateral agenesis of maxillary lateral incisors

The aim of this paper is to evaluate the dimensions and morphology of cranial base and sella turcica in patients with bilateral agenesis of maxillary lateral incisors (BMLI). This retrospective study was conducted on lateral cephalometric radiographs of 34 female patients with BMLI (17.69 ± 2.96 years) and 34 female patients with complete dentation and skeletal Class 1 relationship serving as a control group (17.22 ± 2.2 years). Basicranial and maxillomandibular variables together with linear dimensions and morphology of sella turcica were evaluated. Differences between groups were analyzed by Student's t test for parametric variables and Mann-Whitney U test for nonparametric variables. Chi-square test followed by post hoc test with Bonferroni correction was used for categoric variables (p < 0.05). When compared to control group, N-S-Se angle was less negative, dimensions between Ba-Se, N-Ba, and N-Ar were larger, and SNA angle was smaller in BMLI group. There were no significant differences between groups regarding the linear dimensions of sella turcica. However, variations in sella turcica morphology were more frequent in BMLI group (n = 17; 50%) when compared to control group (n = 2; 5.8%). The most common morphologic variations in BMLI group were oblique anterior wall (20.6%) and irregularity (notching) in the posterior part of sella turcica (14.7%). The present study showed a statistically significant relationship between the presence of BMLI with some craniofacial parameters and morphological variations of sella turcica. This information may be useful as an additional and early diagnostic tool for BMLI and to highlight the possible links to its development.

Defining dysmorphic facial features in congenital Zika syndrome

Congenital Zika syndrome (CZS) constitutes a recently identified malformation caused by Zika virus infection during pregnancy. Limited data is available to date on the facial dysmorphic features of these patients. This study evaluated the facial dysmorphisms of children with CZS, compared with clinically healthy children, using clinical examination and standardized photographic images. Sixty-three children with CZS (9.70 ± 3.2 months-age), and 31 Controls (8.67 ± 6.2 months-age) joined the study. Seven out of 15 indices differed between groups: midfacial height (MFH)/horizontal facial reference (HFR) (p = .0003), interalar distance/HFR (p = .0027), nasal root depth/MFH (p = .0030), posterior nasal length/MFH (p = .0002), vertical position of the ear/MFH (p <.0001), ear length/MFH (p = .0005), chin height/total facial height (CH/TFH) (p <.0001). A CH/TFH of 0.229 showed 93.9% sensitivity and 80.6% specificity in diagnosing CZS. Children with CZS had broad, short faces, decreased intercanthal distance, short posterior nasal length, prominent nasal root, broad nasal wings, and high-set and long ears. Increased chin height index provided the most accurate diagnostic potential.

Cephalometric Evaluation of Anterior Cranial Base Slope in Patients with Skeletal Class I Malocclusion with Low or High SNA and SNB Angles

Objective

In the cephalometric analyses, it is observed that both SNA and SNB angles are higher or lower than normal for some skeletal Class I patients. The aim of this study was to assess the correlation between low or high SNA, SNB angles, and anterior cranial base (ACB) slope.

Methods

One hundred and seventeen skeletal Class I patients (45 males with a mean age of 14.5 years, 72 females with a mean age of 14.4 years) were evaluated in three groups. Group 1(n=40): Control group, individuals with normal SNA(82°±2°), and SNB(80°±2°) values. Group 2 (n=37): Patients with SNA>84° and SNB >82°, Group 3 (n=40): Patients with both SNA and SNB values lower than 78°. On the cephalometric radiographs, three angulars (SN/FH; anterior cranial base, Ba-S/FH; posterior cranial base, SN-Ba; total cranial base) and seven linear (S-FH, N-FH, Δ, Ba-S, Ba-N, Ba-A, Ba-B) measurements were performed to analyze the vertical and horizontal positions of the S and N points and thereby the ACB slope. One-way ANOVA and Kruskal Wallis tests were used for statistical analysis.

Results

The ACB slope was observed to be relatively flatter in Group 2, and steeper in Group 3 (p<0.05). The location of the S and N points in the sagittal plane did not significantly affect the SNA and SNB. However, the vertical position of the S and N points was a factor determining the inclination of the ACB, therefore the SNA and SNB.

Conclusion

ACB slope directly affected SNA and SNB measurements. ACB might lead to misleading results when used as a reference plane.

Skeletal open bite cranial base characteristics in young Latin-American individuals with class I, II and III malocclusions: An observational study

OBJECTIVE

This study aimed to compare cranial base linear and angular measurements between individuals with skeletal open bite and different sagittal skeletal relationships.

MATERIALS AND METHODS

This observational and cross-sectional study included 101 lateral radiographs of young Latin-American individuals with skeletal open bite that met the inclusion criteria and were collected from a private radiological centre. Three groups were formed. Groups 1, 2 and 3 included individuals with skeletal open bite (negative overbite and FMA>30°) and Class I (n=31), II (n=35) and III (n=35) sagittal skeletal relationship, respectively. The anterior and posterior cranial bases (SN and SBa), and cranial base angles (BaSN and ArSN) were measured. Groups were compared with one-way analysis of variance and post-hoc Scheffé tests. The influence of predictor variables on the cranial base were evaluated with linear regressions (α=0.05).

RESULTS

The cranial base angles were significantly smaller (approximately 3° to 5°) in the skeletal open bite Class III group (BaSN=127.97°± 5.86°, ArSN=120.19°±6.12°) when compared with the other groups. BaSN angle, Class I versus Class III (p<0.001) and Class II versus Class III (p<0.001). ArSN angle, Class I versus Class III (p=0.005) and Class II versus Class III (p=0.026). Multiple linear regressions showed that sex had a significant influence on both cranial base dimensions with men showing larger values than women.

CONCLUSIONS

Skeletal open bite Class III individuals show a smaller cranial base angle than Skeletal open bite Class I or II individuals.

Influence of the cranial base flexion on Class I, II and III malocclusions: a systematic review

Objective:

The aim of this study was to perform a systematic review on the morphological characteristics of the skull base (flexion, anterior length and posterior length) and the concomitant development of malocclusions, by comparing differences in dimorphism, ethnicity and age.

Methods:

The articles were selected by means of electronic search on BBO, MEDLINE and LILACS databases from 1966 to 2016. A qualitative evaluation of the methodologies used on the articles was also performed.

Results:

Although the literature on this topic is abundant, only 16 articles were selected for the present systematic review. The cranial base angle itself does not seem to play a significant role in the development of malocclusions. In fact, the cranial base angle is relatively stable at the ages of 5 to 15 years.

Conclusions:

A more obtuse angle at the skull base, in association or not with a greater anterior length of the cranial base, can contribute to the development of Class II division 1 malocclusions. On the other hand, a more acute angle at the skull base can contribute to a more anterior positioning of the mandible and to the development of Class III malocclusions.

Cranial base characteristics in anteroposterior malocclusions: A meta-analysis

OBJECTIVE

To investigate cranial base characteristics in malocclusions with sagittal discrepancies.

MATERIALS AND METHODS

An electronic search was performed in PubMed, Embase, Web of Science, and the Cochrane Library. A fixed- or random-effect model was applied to calculate weighted mean difference with 95% confidence intervals (CIs) according to statistical heterogeneity. Outcome measures were anterior, posterior, and total cranial base length and cranial base angle. Sensitivity analysis and publication bias were conducted.

RESULTS

Twenty studies that together included 1121 Class I, 1051 Class II, and 730 Class III cases qualified for the final analysis. Class III malocclusion demonstrated significantly reduced anterior (95% CI: -1.74, -0.53; P < .001 vs Class I; 95% CI: -3.30, -2.09; P < .001 vs Class II) and total cranial base length (95% CI: -3.33, -1.36; P < .001 vs Class I; 95% CI: -7.38, -4.05; P < .001 vs Class II). Further, Class II patients showed significantly greater anterior and total cranial base length than did Class I patients (95% CI: 0.51, 1.87; P < .001 for SN; 95% CI: 2.20, 3.30; P < .001 for NBa). Cranial base angle was significantly smaller in Class III than in Class I (95% CI: -3.14, -0.93; P < .001 for NSBa; 95% CI: -2.73, -0.68; P  =  .001 for NSAr) and Class II malocclusions (95% CI: -5.73, -1.06; P  =  .004 for NSBa; 95% CI: -6.11, -1.92; P < .001 for NSAr) and greater in Class II than in Class I malocclusions (95% CI: 1.38, 2.38; P < .001 for NSBa).

CONCLUSIONS

This meta-analysis showed that anterior and total cranial base length and cranial base angle were significantly smaller in Class III malocclusion than in Class I and Class II malocclusions, and that they were greater in Class II subjects compared to controls.

Evaluating condylar position in different skeletal malocclusion patterns: A cephalometric study

Context

The cranial base and variations in its morphology affect the anterior-posterior positioning of jaws causing changes in the glenoid fossa and condylar position.

Aims

To evaluate the condylar position in patients with different skeletal sagittal malocclusion patterns.

Materials and Methods

Pretreatment lateral cephalometric radiographs of 112 subjects (both males and females) were categorized into three classes (Class I, Class II, Class III) based on their ANB angulation and studied for N-S-Ar (saddle angle), S-Ar-Go (articular angle), S-Ar (posterior cranial base length).

Statistical Analysis

Shapiro-Wilk test was done to check for normality of the distribution of values. Groups were evaluated using parametric tests (one-way ANOVA). Significance for all tests was predetermined asP< 0.05.

Results

N-S-Ar and S-Ar-Go and also S-Ar did not vary significantly in all the three classes. N-S-Ar and S-Ar-Go angles have shown a significant negative correlation in all the three classes.

Conclusions

There is no significant difference in condylar position in different skeletal malocclusion patterns. N-S-Ar and S-Ar-Go angles show a negative correlation in any skeletal malocclusion pattern.

Craniofacial cephalometric morphology in 8-year-old children with operated sagittal synostosis

OBJECTIVES

To evaluate cephalometrically craniofacial morphology in children with operated sagittal synostosis and to compare the findings with age- and sex-matched controls.

SETTING AND SAMPLE POPULATION

Forty-two children (37 boys) with operated primary sagittal synostosis were compared retrospectively with age- and sex-matched controls from lateral cephalograms taken at a mean age of 8.1 (range 7.0-8.9) years.

MATERIAL AND METHODS

The operations had been performed between the ages of 2 months and 6.3 years at three Finnish hospitals. The surgical methods included strip craniectomy, pi-plasty and cranial vault expansion. A paired Student's t-test and Pearson's correlation analysis were used in the statistical analyses.

RESULTS

Children with operated sagittal synostosis had wide cranial base angles and their mandibles were retrognathic with labially inclined lower incisors relative to the controls. Age at craniosynostosis operation did not correlate with the cranial base angle.

CONCLUSION

This study suggests that children with operated sagittal synostosis have minor distinctive morphological features in the cranial base and mandible. Orthodontic evaluation of craniofacial growth is recommended.

Cranial-base morphology in adults with skeletal Class III malocclusion

INTRODUCTION

The objectives of this study were to clarify the characteristics of cranial-base morphology in adults with skeletal Class III malocclusion and investigate factors relating to the establishment of a skeletal Class III malocclusion.

METHODS

Initial lateral cephalograms of women were examined. Subjects with an ANB angle of 0° to 4°, normal overjet and overbite, and a Class I molar relationship were classified as Class I (n = 86). Those with an ANB angle less than -1°, a Wits appraisal less than 2 mm, a negative overjet, and a Class III molar relationship were the Class III group (n = 86) in this study. Angular, linear, and coordinate measurements were made. Multivariate analysis of variance and the Student t test were used to analyze significant differences between the 2 groups. Discriminant analysis, logistic regression analysis, and decision analysis were used to identify which cranial-base and maxillomandibular variables influenced the establishment of a skeletal Class III malocclusion.

RESULTS

The Class III group had smaller values for NSBa, SeSBa, FH-SSe, and FH-SBa. Sphenoidale and basion were more inferior and anterior than those of the Class I group. There was no difference in the anterior and posterior cranial-base lengths between the groups. Greater mandibular length was the first major characteristic in the Class III group, followed by smaller values for SeSBa and NSBa.

CONCLUSIONS

Cranial-base morphology in adults with a skeletal Class III malocclusion is different from that in a skeletal Class I malocclusion. Smaller cranial-base angles, steeper posterior cranial bases, more inferiorly positioned sphenoidale, and more anteriorly positioned basion are major characteristics of skeletal Class III malocclusions. These characteristics play important roles in the establishment of a skeletal Class III malocclusion.

Geometric morphometric analysis of craniofacial variation, ontogeny and modularity in a cross-sectional sample of modern humans

This investigation aimed to quantify craniofacial variation in a sample of modern humans. In all, 187 consecutive orthodontic patients were collected, of which 79 were male (mean age 13.3, SD 3.7, range 7.5-40.8) and 99 were female (mean age 12.3, SD 1.9, range 8.7-19.1). The male and female subgroups were tested for differences in mean shapes and ontogenetic trajectories, and shape variability was characterized using principal component analysis. The hypothesis of modularity was tested for six different modularity scenarios. The results showed that there were subtle but significant differences in the male and female Procrustes mean shapes. Males were significantly larger. Mild sexual ontogenetic allometric divergence was noted. Principal component analysis indicated that, of the four retained biologically interpretable components, the two most important sources of variability were (i) vertical shape variation (i.e. dolichofacial vs. brachyfacial growth patterns) and (ii) sagittal relationships (maxillary prognatism vs. mandibular retrognathism, and vice versa). The mandible and maxilla were found to constitute one module, independent of the skull base. Additionally, we were able to confirm the presence of an anterior and posterior craniofacial columnar module, separated by the pterygomaxillary plane, as proposed by Enlow. These modules can be further subdivided into four sub-modules, involving the posterior skull base, the ethmomaxillary complex, a pharyngeal module, and the anterior part of the jaws.

The effect of anatomic factors on tongue position variability during consonants

PURPOSE

This study sought to investigate the effect of palate morphology and anthropometric measures of the head on positional variability of the tongue during consonants.

METHOD

An electromagnetic tracking system was used to record tongue movements of 21 adults. Each talker produced a series of symmetrical VCV syllables containing one of the consonants /t, d, s, z, , t, k, g, j/ and corner vowels /i, a, u/. Distributions of x, y, and z coordinates at maximum tongue elevation were used to represent tongue position variability across contexts. Anthropometric palate and head measures were also obtained.

RESULTS

Positional variability of the tongue differed between the front (e.g., alveolar and post-alveolar) and back (velar) consonant groups. A correlational analysis showed that tongue position variability of the front consonants was explained, to a degree, by palate curvature and palate length. The variability of the back consonants was not explained by any structural measures.

CONCLUSION

Palate morphology needs to be taken into account when making observations regarding the extent of tongue position variability during consonants in research and in achieving clinical goals.

Lengths of the maxillary central incisor, the nasal bone, and the anterior cranial base in different skeletal malocclusions

OBJECTIVE

Based on the results of previous studies of osseous structures within the frontonasal field in patients with a known malformation in the frontonasal field, the aim of the present study was to clarify whether the same structures were malformed in patients with severe skeletal malocclusions.

MATERIAL AND METHODS

Incisor, nasal, and cranial base lengths were measured on lateral radiographs of adult patients with skeletal malocclusions, including open bite (n=35), mandibular overjet (n=56), maxillary overjet (n=31), deep bite (n=19), and compared with those of a control group with neutral occlusion and normal craniofacial morphology (n=39). Two-way ANOVA tests were used to evaluate differences in lengths between groups and gender.

RESULTS

Statistically shorter maxillary central incisor length was found in the open bite group (p<0.05), the mandibular overjet group (p<0.001), and in the deep bite group (p<0.001) compared to the controls. Nasal bone length was shorter in the maxillary overjet group compared to controls (p<0.05).

CONCLUSIONS

The lengths of the maxillary central incisor and nasal bone, both parameters located in the frontonasal field, are affected in different skeletal malocclusions. The present findings, especially the deviation of the upper incisor length in different skeletal malocclusions, are considered relevant for orthodontic diagnostics and treatment.

Permutation method for evaluating topographic craniofacial correlations

INTRODUCTION

Correlations between cephalometric measurements are frequently assumed to represent biologic associations. However, a significant portion of such correlations might arise from purely geometric dependencies, when measurements share common landmarks. Analytic calculation of this topographic component is difficult. The purpose of this study was to propose a permutation method for evaluating the topographic component of cephalometric correlations.

METHODS

The method consisted of creating a virtual sample of cephalometric tracings (landmark configurations) from the original biologic sample under investigation. Each novel landmark configuration was constructed by assigning coordinates to the cephalometric points; the coordinates of each point were taken randomly from the original sample, each from a potentially different subject. Correlation analysis was performed separately on both samples and the results compared. Biologic meaning was ascribed only when there was a significant difference in correlation values between the samples. Confidence intervals for assessing statistical significance were calculated by using a randomization approach. The method was tested on a sample of 170 radiographs to evaluate the correlation between cranial base angle (NSBa) and angles SNA and SNB, as well as between ANB angle and the Wits appraisal.

RESULTS

No biologic association was found between ANB and Wits, or between NSBa and SNA. The biologic correlation between NSBa and SNB was statistically significant but low (r(2) = 12%).

CONCLUSIONS

Topographic associations between cephalometric measurements are ubiquitous and difficult to assess. The proposed method enables evaluation of their relative strength without the need for analytic solutions.

Morphological integration between the cranial base and the face in children and adults

The primary aim of the present study was to assess morphological covariation between the face and the basicranium (midline and lateral), and to evaluate patterns of integration at two specific developmental stages. A group of 71 children (6-10 years) was compared with a group of 71 adults (20-35 years). Lateral cephalometric radiographs were digitized and a total of 28 landmarks were placed on three areas; the midline cranial base, the lateral cranial base and the face. Geometric morphometric methods were applied and partial least squares analysis was used to evaluate correlation between the three shape blocks. Morphological integration was tested both with and without removing the effect of allometry. In children, mainly the midline and, to a lesser extent, the lateral cranial base were moderately correlated to the face. In adults, the correlation between the face and the midline cranial base, which ceases development earlier than the lateral base, was reduced. However, the lateral cranial base retained and even strengthened its correlation to the face. This suggests that the duration of common developmental timing is an important factor that influences integration between craniofacial structures. However, despite the apparent switch of primary roles between the cranial bases during development, the patterns of integration remained stable, thereby supporting the role of genetics over function in the establishment and development of craniofacial shape.

Quantification of cranial base growth during pubertal growth

OBJECTIVE

To quantify longitudinal cranial base growth from prepubertal through postpubertal stages of development, as defined by biological indicators of individual skeletal maturity (cervical vertebral maturation - CVM) method and to determine if there is sexual dimorphism resulting from cranial base growth.

DESIGN

A longitudinal cephalometric study.

SETTING

The Dental School of Paulista University, Brazil.

PARTICIPANTS

36 subjects (21 females, 15 males) who were part of a longitudinal growth study and exhibited normal facial and normal vertical growth patterns.

METHODS

Growth maturation of cervical vertebrae stages was assessed by two examiners independently. Cranial base measurements were carried out by one individual and repeated after one month. The growth increments over time were assessed with the one-way repeated-measures analysis of variance and post hoc Tukey multiple comparisions.

RESULTS

There were no significant gender differences. There was a significant increase in all cephalometric measures between the different time points. Ba-Na showed the greatest amount of growth (mean change=2.8 mm). From T2-T3, the greatest amount of growth was found for Se-Na (mean change=3.4 mm) and the lowest for CC-Na (mean change=1.4 mm). Comparing overall changes (T1-T3) all the measurements showed statistically significantly increases (P<0.05). For all comparisons of between-stage changes the cranial base grew more than 2.0 mm during the pubertal growth.

CONCLUSIONS

Linear variables of cranial base showed significant growth during pubertal stages (pre-peak, peak and post-peak). No significant differences.