Cranial Base Angulation Research Articles

Mandibular asymmetries in brazilian adolescents: prevalence and associated factors

Objectives : Estimate the prevalence of mandibular asymmetries in Brazilian adolescents and investigate the demographic and skeletal factors associated to the asymmetries. Methods : Cone beam computed tomography (CBCT) images from 376 individuals aged from 10 to 19 were analysed to investigate mandibular asymmetry categorized as relative mandibular symmetry, moderate asymmetry, and severe asymmetry. Exposure variables included sex, age, side of mandibular deviation, sagittal and vertical skeletal pattern of the individuals, and cranial base angulation. The chi-square test was used to evaluate the association among asymmetry and the exposure variables. Gross prevalence rations were estimated and adjusted by Poisson regression with robust variance. Significance level was established at 5%.

Cranial Shape Changes in Nonsyndromic Unilateral Lambdoid Synostosis after Open Posterior Vault Remodeling.

The purpose of this study was to quantify change in cranial morphology in patients with nonsyndromic unilateral lambdoid craniosynostosis (ULC) from presentation (t0), after open posterior switch-cranioplasty (t1), and at 2-year follow-up (t2). Volumetric, linear, and angular analysis were performed on computed tomographic scans at the three time points and against normal control subjects. Significance was set at P < 0.05. Twenty-two patients were included. ULC cranial vault asymmetry index was higher than in control subjects before surgery (6.22 ± 3.55) but decreased after surgery (3.00 ± 2.53) to become comparable with the normal asymmetry range present in the controls. After surgery, both diagonals increased, but more on the fused side. In the 2 years after surgery, both diagonals in patients with ULC grew proportionately, but the fused diagonal remained slightly shorter than the patent side. Total cranial volume was higher in patients with ULC than in control subjects after surgery but became comparable at t2. Cranial base angulation improved by t2 but did not approach normal, and ear position remained unchanged. The facial twist was higher than in controls at t0 and t1 but was comparable at t2. Coronal asymmetry improved with surgery but remained undercorrected at t2, with the greatest residual asymmetry at opisthion. Open-switch cranioplasty normalizes cranial vault asymmetry index by increasing the fused cranial diagonal more than the patent side and is stable at 2 years. Skull base twist does not normalize, but facial twist approaches normal. Technique improvement should focus on residual coronal asymmetry present at opisthion. Therapeutic, IV.

Employing Spherical Harmonics in Assessing the 3D Shape Variation and Evolutionary Potential of Human Sphenoidal Sinuses

The evolutionary potential and shape variation of the human sphenoidal sinus are unknown. Moreover, a consensus about the function or evolutionary forces that influence variation of paranasal sinuses among humans remains unestablished. One initial approach to address this lies in determining the covariance of sinus shape with surrounding morphology. The sphenoidal sinus is centrally located within the basicranium at the intersection of the three cranial fossae, and is adjacent to the synchondroses where primary cranial base angulation occurs. The angulation of the cranial base and its relative orientation with the face is a distinctive, derived trait in Homo sapiens and is important to our understanding of the evolution of our species. Yet, the shape of the sphenoidal sinus is highly variable and cannot be quantified with traditional landmarking methods. Originally developed in gravitational physics, spherical harmonics has been successfully leveraged in biological morphological studies to quantify and assess 3D shape variation of complex structures. This research will use spherical harmonics to for the first time quantify the 3D shape of the sphenoidal sinuses and assess their covariation with the sphenoid body. By demonstrating the utility of spherical harmonics for human morphometric research, we are opening up new ways for investigating biological and evolutionary questions of human anatomical features that to date have been difficult to evaluate.Here we preliminarily analyze the covariance of sphenoid sinus and basicranial shape. The sphenoidal sinuses of 120 human crania were segmented (Avizo) from CT scans. We quantified the three‐dimensional shape variation of sphenoidal sinuses using spherical harmonic analyses (SHARM, Matlab), producing coefficients comparable to traditional landmarks placed virtually on the basicranial surface. Landmarks were chosen that capture the general shape of the sphenoid body. Two‐Block Partial Least Squares (2B‐PLS) analyses revealed no significant covariation (p=0.59) between the shape of the sphenoidal sinus and its surrounding bony architecture. This indicates the establishment of sinus shape occurring independently of the surrounding bone. This is contrary to previous research, which has suggested that paranasal sinuses opportunistically pneumatize within the available space of their respective cranial bones. Future research will need to investigate this relationship further with additional sets of landmarks representing different developmental regions and functional matrices that interface with the sphenoid body. This research is also foundational to investigate to what extent mutual constraint among these traits may exist in the ability to respond to natural selection, i.e. evolvability.

The chondrocranial key: Fetal and perinatal morphogenesis of the sphenoid bone in primates

The sphenoid bone articulates with multiple basicranial, facial, and calvarial bones, and in humans its synchondroses are known to contribute to elongation of the skull base and possibly to cranial base angulation. Its early development (embryological, early fetal) has frequently been studied in a comparative context. However, the perinatal events in morphogenesis of the sphenoid have been explored in very few primates. Using a cross-sectional age sample of non-human primates (n=39; 22 platyrrhines; 17 strepsirrhines), we used microcomputed tomographic (µCT) and histological methods to track age changes in the sphenoid bone. In the midline, the sphenoid expands its dimensions at three growth centers, including the sphenooccipital, intrasphenoidal (ISS) and presphenoseptal (PSept) synchondroses. Bilaterally, the alisphenoid is enlarged via appositional bone growth that radiates outward from cartilaginous parts of the alisphenoid during midfetal stages. The alisphenoid remains connected to the basitrabecular process of the basisphenoid via the alibasisphenoidal synchondrosis (ABS). Reactivity to proliferating cell-nuclear antigen is observed in all synchondroses, indicating active growth perinatally. Between mid-fetal and birth ages inSaguinus geoffroyi, all synchondroses decrease in the breadth of proliferating columns of chondrocytes. In most primates, the ABS is greatly diminished by birth, and is likely the earliest to fuse, although at least some cartilage may remain by at least one-month of age. Unlike humans, no non-human primate in our sample exhibits perinatal fusion of ISS. A dichotomy among primates is the orientation of the ABS, which is more rostrally directed in platyrrhines. Based on fetalSaguinus geoffroyispecimens, the ABS was initially oriented within a horizontal plane, and redirects inferiorly during late fetal and perinatal stages. These changes occur in tandem with forward orientation of the orbits in platyrrhines, combined with downward growth of the midface. Thus, we postulate that active growth centers direct the orientation of the midface and orbit before birth.

Variation and Covariation of Size and Shape of the Sphenoidal Sinus in H. sapiens

No consensus about the function or evolutionary forces that influence variation of paranasal sinuses among humans has been established. By establishing the covariance of sinus shape with surrounding morphology, researchers may better develop hypotheses about the potential for independent evolution in the sinuses. The sphenoidal sinuses are rarely studied, despite being centrally located within the basicranium, at the intersection of the three cranial fossae and adjacent to the synchondroses, the location of cranial base angulation. The angulation of the cranial base and its relative orientation with the face is a distinctive, derived trait in Homo sapiens and is important to our understanding of the evolution of our species, yet there are aspects of that anatomy (the sphenoidal sinuses) that have not yet been investigated for their variation and influence in this highly integrated region. Previous research has shown that cranial base angulation is correlated with sphenoidal sinus size variation. Yet, the covariance of size, shape, and orientation of the cranial fossae have not been explored, though these likely have a developmental and evolutionary relationship with the sphenoidal sinus. Here we analyze the covariance of size and shape in the sphenoid sinus with metrics of the cranial base captured using geometric morphometric techniques. Computed tomography (CT) scans of 45 adult human crania were digitally segmented for analysis. Cranial fossa shape was captured with landmarks, while sinus volume was measured from manual segmentation of CT images. Regression analyses were performed between the landmark data and the sinus volume data to assess their covariation. Using a separate sample, we will analyze the three-dimensional shape of the sphenoidal sinus (i.e., the volumetric apportionment) using spherical harmonic coefficients, and compare its variance to variation in the shape of the cranial fossae and anterior cranial base using Two Block Partial Least Squares (TB-PLS) analyses. Previous findings support the existence of a relationship between basicranial angulation and sinus volumetric variation, but not the lateral expansion or shape of the posterior brain. These findings suggest that the sphenoidal sinus may be influenced by the shape and relative position of anterior fossa. These relationships likely represent the influence of the soft tissue anatomy (including the brain, pituitary gland, and the internal epithelial tissues) on the dimensions of the sphenoid, and thus the trajectory of its pneumatization. We expect the morphology of the sinus to demonstrate similar relationships. These findings on the pattern of covariation inform the directions of future research on the evolution and development of the sphenoidal sinuses and basicranium.

Correlation Between Cranial Base Morphology and Skeletal Maloclusion in a Sample of Sudanese Orthodontic Patients

Objective: This study aimed to evaluate the relationship between the cranial base and jaw base in a sample of Sudanese orthodontic patients. Material and methods: one hundred and twenty lateral Cephalograms from university of Khartoum orthodontic department archive 60 males, 60 females, age 18.3 ± 4.3 years old, were classified into 3 sagittal malocclusion groups (40 individuals each) according to their ANB angle. A cephalometric analysis of the study variables of the cranial base (NSBa, N-S, S-Ba, N-Ba) and jaws bases (SNA, SNB, ANB, A-Co, Gn-Co) was carried out, the morphological characteristics of the cranial and jaw bases in the three groups were compared using One-way ANOVA test and Pearson’s coefficient correlation analysis. Results: Cranial base angle and cranial base lengths did not show significant differences between the main classes of malocclusion studied. However, jaw size was statistically significant different between the 3 groups, longer maxilla was found in Class II group and the mandible was longer in Class III group. Strong significant relation was found between SNA, SNB and NSBa in the three groups. Positive correlation was found between cranial base lengths and maxillary and mandibular lengths among the three groups. Conclusion: Cranial base angulation and lengths has no major role in developing malocclusion.

Racial Disparity Between Asian and Caucasian Crouzon Syndrome in Skull Morphology.

Racial disparity in pathological consequences in skull growth may impact the treatment plan for different patient populations. This study attempts to explore the differences between Asian and Caucasian cranial morphology in Crouzon syndrome. Ninety-one computed tomographic scans were included (Asian Crouzon syndrome, n = 12; Asian controls, n = 22; Caucasian Crouzon syndrome, n = 16; Caucasian controls, n = 41), and measured using Mimics and 3-matics software. The entire cranial base length was reduced 11.92 mm (P = 0.004) in Asian Crouzon patients, and 14.58 mm (P < 0.001) in Caucasian Crouzon patients, compared to respective controls. The cranial base angle on the facial side of basicranium was more narrowed in Crouzon syndrome in both races, with similar changes of degrees (9.61°, P = 0.002, in Asian Crouzon; 9.20°, P = 0.019, in Caucasian Crouzon). However, the intracranial side was statistically more narrowed only in the Asian group (9.86°, P = 0.003). Both Asian and Caucasian Crouzon patients developed reduced posterior fossa volume, by 15% (P = 0.034) and 17% (P = 0.004), respectively. However, Caucasian Crouzon patients developed a more shortened anterior and middle cranial base, than that of Asian patients. The separation of lateral pterygoids was only significantly increased in Caucasian patients (5.49°, P < 0.001). Crouzon syndrome causes a shortened, widened, and kyphotic cranial base across both races. It also restricts the development of the posterior cranial fossa. However, the skull malformation is not the same between populations: Asian Crouzon patients developed more narrowed cranial base angulation on the intracranial side of basicranium, while Caucasian Crouzon patients developed more widened lateral pterygoids.

Airway Development Relevant to Cranial Vault Suture Synostosis Subtype in Apert Syndrome

Introduction: Based on an established classification system of Apert syndrome subtypes, we aim to directly analyze the correlation between segmented airway volume changes and different skull suture synostosis, so as to provide individualized surgical planning for each subgroup of Apert patients. Methods: CT scans of 44 unoperated Apert syndrome and 53 controls were included and subgrouped as: type I. Bilateral coronal synostosis; type II. Pansynostosis; type III. Perpendicular combinations of cranial vault synostosis. CT scans were measured using Mimics and 3-matics software. Results: Type I developed a 41% ( P = .116) reduction in the nasal cavity, yet a normal sized pharyngeal airway. The reduced nasal airway was linked to the decreased cross sectional area ( r = 0.598, P = .001), vertical dimension ( r = 0.719, P &lt; .001), and narrower width ( r = 0.727, P &lt; .001). Type II developed proportionally reduced nasal airway and pharyngeal airway volumes (both 47%, P = .113 and P = .041), along with the proportionally restricted cross sectional areas at choana and condylion levels by 62 to 65%. This reduction is related to the cranial base length ( r = 0.712, P = .048), and also cranial base angulation ( r = 0.780, P = .023). Nasal and pharyngeal airway developed normal volume in type III. However, the cross sectional areas at the gonion level diminished by 74% ( P &lt; .001). Conclusion: Airway development is influenced by subtype of Apert suture synostosis. Type II pansynostosis Apert patients developed synchronous reduced nasal and pharyngeal airways, which is correlated with the slightly flattened cranial base. Type I bicoronal patients have a smaller nasal cavity, but normally sized hypopharynx. Yet, type III patients developed normal nasopharyngeal airway volume overall.

3D Evaluation of the Relationship between Different Vertical Growth Patterns and Cranial Base Angulations

Objective This study aimed to compare cranial base angulations in subjects with high-angle, low-angle, and normal-angle vertical growth patterns using cone beam computed tomography (CBCT). Design This study is a retrospective clinical research. Settings This study was carried out at the Dentistry Faculty of Eskisehir Osmangazi University. Participants According to skeletal vertical face growth patterns, 78 subjects (48 females and 30 males, average age: 13.19 ± 1.73 years) were divided equally into three groups: high angle, low angle, and normal angle groups. Main Outcome Measures Cephalometric images were derived from CBCT, and patients were classified according to the SN-GoGn angle (sella-nasion, gonion gnathion angle). Sagittal, axial, and coronal cranial base angulations were measured in three-dimensional (3D) CBCT images. Data were analyzed using the Kolmogorov-Smirnov normality, Kruskal-Wallis, and Mann-Whitney U statistical tests. Results There were statistically significant differences between the low-angle and high-angle groups according to sagittal cranial base angulation parameters ( p = 0.01). Conversely, there were no statistically significant differences between vertical facial growth patterns according to coronal and axial cranial angle variables ( p > 0.05). Conclusion According to the study results, there were no effects of cranial base angulations in two planes (coronal and axial) on different vertical skeletal growth patterns. In the sagittal cranial base angulation parameter, the high-angle group showed greater angulation values than the low-angle group. CBCT may be helpful for evaluating, diagnosing, and predicting 3D cranial base differences.

Assessing Facial Asymmetry in Postoperative Patients With Unilateral Coronal Craniosynostosis.

Despite surgical correction of unilateral craniosynostosis (ULC), complex cranial base angulation can result in partial reversion to preoperative deformity with growth and time. Using 3-dimensional imaging, dysmorphic facial features of ULC in school-age patients were quantified and related to how they contribute to overall facial asymmetry and patient-reported outcomes. Children who underwent surgical correction of ULC were recruited from Yale University and Children's Hospital of Philadelphia. The 3D photographs were analyzed utilizing a Procrustes analysis of shape. Pearson's correlation was used to determine dysmorphic features' impact on overall asymmetry. Patients were stratified into "moderate" and "severe" asymmetry. Finally, asymmetry was correlated to patient-reported outcome scores. Statistical analysis was performed with SPSS-25 with P < 0.05 as statistically significant. Twenty-one patients were included with average age at analysis of 12.3 years. Fifty-seven percent of patients had right-sided fusion. The overall Procrustes analysis indicated a root mean square difference of 2.21 mm. Pearson's correlation indicated that the facial middle 3rd (P ≤ 0.001), orbital dystopia (P < 0.001), chin point deviation (P = 0.011), and nasal root angulation (P = 0.019) contributed most to overall asymmetry. Patients in the severe asymmetry cohort had greater facial middle-third asymmetry (P < 0.001) and orbital dystopia (P < 0.001). Asymmetry did not correlate with patient-reported outcomes. Patients with ULC have persistent facial asymmetry at school-age with the greatest levels of asymmetry in the facial middle-third, orbit, and nasal root. Beyond the cranial dysmorphology, initial skull base angulation in unilateral coronal craniosynostosis manifests in long-term mid and lower-third facial asymmetry.

Where does the cranial base flexion take place in humans?

The modern human has the most flexed cranial base among all living animals. The flexure allowed a larger cranial volume to accommodate a greater brain. Spheno-occipitalis synchondrosis (SOS) has been largely responsible for cranial base flexion, between the sphenoid and the Pars basilaris of the occipital bone. The objective of this work is to evaluate the real place of skull base flexure. Analysis based on 50 magnetic resonance imaging from normal adult subjects were used to evaluate normal place for cranial base angulation (CBA). The vertex of the cranial base angle in all individuals occurred intrinsically in the sphenoid bone. In humans, cranial base flexure had a specific pre-chordal origin, rather than in the transition between pre-chordal and chordal plates and occurred in the inner sphenoidal bone.

S12-14 SESSION 12: FACIOCRANIOSYNOSTOSIS – PART II THE CLASSIFICATION OF APERT SYNDROME, BASED ON CRANIAL VAULT SUTURE SYNOSTOSIS ------DIFFERENT CRANIAL BASE ANGULATIONS AND AIRWAY COMPROMISE

Introduction: Apert syndrome patients are different in clinical pathology, including obstructive sleep apnea, cleft palate and mental deficiency. These functional deficiencies may be due to anatomic deformities, which may be caused by different forms of associated suture fusion. Therefore, a classification system of Apert syndrome based on the type of craniosynostosis pattern might be helpful in determining treatment choices. Methods: CT scans of 31 unoperated Apert syndrome and 51 controls were included and subgrouped as: class I. Bilateral coronal synostosis; class II. Pansynostosis; class III. Perpendicular combination synostosis: a. unilateral coronal and metopic synostosis; b. sagittal with bilateral/unilateral lambdoid synostosis; c. others. Results: Class I, bilateral coronal synostosis is the most common (55%) subtype. The cranial base angulation of class I was normal, however, the cranial base angulation on the cranium side of the skull in class II (N-S-BA) increased 12.16 degrees (p=0.006), while the facial side cranial base angle (N-SO-BA) of class III-a decreased 4.31 degrees (p=0.035) over time. The external cranial base linear measurements of class I showed more evident reduction in anterior craniofacial structures than posterior, while other subtypes developed more severe shortening in the posterior aspects. Conclusion: Bicoronal synostosis is the most common subtype of Apert syndrome with the normalized cranial base angulation. Combined pansynostosis patients have flatter cranial base, while the combined unilateral coronal synostosis have a kyphotic cranial base. Class I have more significant nasopharyngeal airway compromise in a vertical direction, while class II and class III have more limited oropharyngeal space.

Classification of Subtypes of Apert Syndrome, Based on the Type of Vault Suture Synostosis.

Apert syndrome patients are different in clinical pathology, including obstructive sleep apnea, cleft palate, and mental deficiency. These functional deficiencies may be due to anatomic deformities, which may be caused by different forms of associated suture fusion. Therefore, a classification system of Apert syndrome based on the type of craniosynostosis pattern might be helpful in determining treatment choices. CT scans of 31 unoperated Apert syndrome and 51 controls were included and subgrouped as: class I. Bilateral coronal synostosis; class II. Pansynostosis; and class III. Perpendicular combination synostosis: a. unilateral coronal and metopic synostosis; b. sagittal with bilateral/unilateral lambdoid synostosis; and c. others. Class I is the most common (55%) subtype. The cranial base angulation of class I was normal; however, the cranial base angulation on the cranium side of the skull in class II increased 12.16 degrees (P = 0.006), whereas the facial side cranial base angle of class IIIa decreased 4.31 degrees (P = 0.035) over time. The external cranial base linear measurements of class I showed more evident reduction in anterior craniofacial structures than posterior, whereas other subtypes developed more severe shortening in the posterior aspects. Bicoronal synostosis is the most common subtype of Apert syndrome with the normalized cranial base angulation. Combined pansynostosis patients have flatter cranial base, whereas the combined unilateral coronal synostosis have a kyphotic cranial base. Class I has more significant nasopharyngeal airway compromise in a vertical direction, whereas classes II and III have more limited oropharyngeal space.

Farklı Maloklüzyonlar ile Kafa Tabanı Açılanmaları Arasındaki İlişkinin Üç Boyutlu Değerlendirilmesi

Aim: This study aimed to evaluate the cranial base angulations in patients with different malocclusions by using cone-beam computed tomography (CBCT). Material-Methods: According to anteroposterior malocclusions, CBCT images of subjects (135 female, 98 male, average age: 13,05±1,79 ) were divided into three groups ; Class I, Class II and Class III. Cephalometric images were obtained from CBCT and patients were classified according to ANB angle. Sagittal, axial and coronal cranial base angulations were measured in three dimensional CBCT images. Cranial base angulation with different anteroposterior malocclusions were analyzed with the Kruskal-Wallis statistical test. Results: Sagittal cranial base measurements showed no significant differences between Class I, II and III groups (p>0.05). Also there were no significant differences between anteroposterior malocclusion groups according to coronal and axial cranial angle variables (p>0.05). Conclusion: According to the results, there were no effect of cranial base angulations in three planes (sagittal, coronal and axial) on different anteroposterior skeletal malocclusions. CBCT may be helpful for detecting and diagnosing morphological differences in anterior and posterior cranial base.

Cranial Base Angulation: Examining Congruence of Interior and Exterior Measurements

Variation in the degree of basicranial flexion plays an important role in the analysis of hominin fossil remains. This variation in the angulation of the cranial base (CBA) is informative of clade distinctions throughout primates, and other mammals, and is informative of both developmental and phylogenetic processes. This is due to its putative covariance with traits such as encephalization and body size. Estimation of the CBA has been traditionally derived from endocranial landmarks. However, more recent analyses suggest that the CBA may be derived from ectocranial landmarks as well. The relative ease of obtaining ectocranial landmarks makes this method especially attractive when considering the time and cost of obtaining endocranial landmark data. To date there has been no comparison of these methods to determine whether or not they are reflecting the same mean angles and variance. This study assesses concordance among the four endocranial techniques and among four ectocranial techniques, and then compares endocranial and ectocranial methods for measuring the CBA.All CBAs are extracted from a sample of 48 tamarins (Saguinus oedipus). Midsagittal radiographs are used to identify four internal landmarks, from which four planes are drawn: clivial, sella, pre‐sphenoid, and sphenoid. Each endocranial angle is calculated from the plane intersections using ImageJ. Seven three‐dimensional ectocranial landmarks are captured using a MicroScribe G2. A total of four CBAs are calculated using a vector‐based method that is then corroborated by CBA extraction using trigonometric methods. All extracted angles are converted to radians prior to statistical analysis. CBA comparisons are performed in R using a Brown‐Forsythe test. Results show no significant difference among the individual variances captured by the four endocranial methods, nor was there a difference between the vector‐based and trigonometric‐based calculations using ectocranial landmarks. However, comparisons among the individual ectocranial methods show significant differences in the variance captured between all but two of these methods. Results also indicate that the variance captured by endocranial CBAs derived from the sella, clivial, and pre‐sphenoid planes is statistically equivalent to that of the ectocranial CBAs derived from the basion, opisthion, spheno‐basion, and prosthion. Morphological dimensions and orientation of the ectocranial and endocranial landmarks are responding to different local factors; internal morphology is influenced by the brain and meninges, while the external morphology is responding to muscle attachments, spacing for soft tissue structures, and interfacing with the vertebral column. Despite these differential influences on morphology, it is possible that the position of the face relative to the neurocranium is overriding these factors. These results are not unexpected as they corroborate the leading hypothesis explaining the variation in the CBA, the spatial packing hypothesis, which has been empirically shown to demonstrate covariation between the CBA, brain size, and facial orientation (kyphosis).

Isolated frontosphenoidal synostosis: a rare cause of synostotic frontal plagiocephaly

Unilateral fusion of the frontoparietal suture is the most common cause of synostotic frontal plagiocephaly. Localized fusion of the frontosphenoidal suture is rare but can lead to a similar, but subtly distinct, phenotype. A retrospective chart review of the authors' craniofacial database was performed. Patients with isolated frontosphenoidal synostosis on CT imaging were included. Demographic data, as well as the clinical and radiographic findings, were recorded. Three patients were identified. All patients were female and none had an identifiable syndrome. Head circumference was normal in each patient. The mean age at presentation was 4.8 months (range 2.0-9.8 months); 2 fusions were on the right side. Frontal flattening and recession of the supraorbital rim on the fused side were consistent physical findings. No patient had appreciable facial angulation or orbital dystopia, and 2 patients had anterior displacement of the ipsilateral ear. All 3 patients were initially misdiagnosed with unilateral coronal synostosis, and CT imaging at a mean age of 5.4 months (range 2.1-10.8 months) was required to secure the correct diagnosis. Computed tomography findings included patency of the frontoparietal suture, minor to no anterior cranial base angulation, and vertical flattening of the orbit without sphenoid wing elevation on the fused side. One patient underwent CT scanning at 2.1 months of age, which demonstrated a narrow, but patent, frontosphenoidal suture. The patient's condition was assumed to be a deformational process, and she underwent 6 months of unsuccessful helmet therapy. A repeat CT scan obtained at 10.7 months of age demonstrated the synostosis. All 3 patients underwent fronto-orbital correction at mean age of 12.1 months (range 7.8-16.1 months). The mean duration of postoperative follow-up was 11.7 months (range 1.9-23.9 months). Isolated frontosphenoidal synostosis should be considered in the differential diagnosis of atypical frontal plagiocephaly.

The relation between facial prognathism and cervical posture in skeletal class I Iraqi adult sample

Background: Biologic mechanisms of the form-function interaction are one of important component of orthodontic diagnosis. The purpose of this study is to search for the statistical associations between natural postural and craniofacial morphologic variables of the head. Materials and methods: The sample comprised natural head posture (NHP) cephalograms of 90 subjects, aged 18 to 25 years. Interpretation of the facial structure was made by using both intracranial and the extra-cranial reference lines in AutoCAD computer program. Results The measures of anteroposterior maxillary position, SNA showed a low negative correlations with the anterior cranial base angulation to true vertical (SN.Ver) and with the cranio-cervical position of the head (SN.OPT),(SN.CVT) The measures of anteroposterior mandibular position, SNB and SNPog, both showed moderate correlations with the anterior cranial base angulation to true vertical (SN.Ver) and with the cranio-cervical position of the head (SN.OPT),(SN.CVT) . Conclusion Regarding the correlations between the variables indicating the degree of facial prognathism in the NHP, and the postural variables of the cervical column, it can be argued that in subjects with forward cervical inclination, a relative decrease in facial prognathism is expected.

Spatial packing, cranial base angulation, and craniofacial shape variation in the mammalian skull: testing a new model using mice

The hypothesis that variation in craniofacial shape within and among species is influenced by spatial packing has a long history in comparative anatomy, particularly in terms of primates. This study develops and tests three alternative models of spatial packing to address how and to what extent the cranial base angle is influenced by variation in brain and facial size. The models are tested using mouse strains with different mutations affecting craniofacial growth. Although mice have distinctive crania with small brains, long faces, and retroflexed cranial bases, the results of the study indicate that the mouse cranial base flexes to accommodate larger brain size relative to cranial base length. In addition, the mouse cranial base also extends, but to a lesser degree, to accommodate larger face size relative to cranial base length. In addition, interactions between brain size, face size, and the widths and lengths of the components of the cranial base account for a large percentage of variation in cranial base angle. The results illustrate the degree to which the cranial base is centrally embedded within the covariation structure of the craniofacial complex as a whole.

Cranial Base Angulation in Brazilian Patients Seeking Orthodontic Treatment

The relationship between cranial base flexion and facial prognathism has been of interest to orthodontists, orthognathic maxillofacial surgeons, and plastic surgeons. This study aimed to identify the cranial base flexion of adults with anteroposterior skeletal disharmony. Because the sample was representing a mixed racial population, the authors performed an investigation to confirm an association with other researches performed in different parts of the world. The results revealed an increase in the cranial base flexion in cases diagnosed as class II skeletal pattern and reduction in the group with class III skeletal pattern. These findings suggested that the characteristics of the Brazilian cases did not differ from some other studies despite various influences of different ethnicities in that population.

Thin-plate Spline Analysis of Craniofacial Growth in Class I and Class II Subjects

To compare the craniofacial growth characteristics of untreated subjects with Class II division 1 malocclusion with those of subjects with normal (Class I) occlusion from the prepubertal through the postpubertal stages of development. The Class II division 1 sample consisted of 17 subjects (11 boys and six girls). The Class I sample also consisted of 17 subjects (13 boys and four girls). Three craniofacial regions (cranial base, maxilla, and mandible) were analyzed on the lateral cephalograms of the subjects in both groups by means of thin-plate spline analysis at T1 (prepubertal) and T2 (postpubertal). Both cross-sectional and longitudinal comparisons were performed on both size and shape differences between the two groups. The results showed an increased cranial base angulation as a morphological feature of Class II malocclusion at the prepubertal developmental phase. Maxillary changes in either shape or size were not significant. Subjects with Class II malocclusion exhibited a significant deficiency in the size of the mandible at the completion of active craniofacial growth as compared with Class I subjects. A significant deficiency in the size of the mandible became apparent in Class II subjects during the circumpubertal period and it was still present at the completion of active craniofacial growth.