Cranial Length Research Articles

Diet, feeding behaviour and echidna beaks: a review of functional relationships within the tachyglossids

Echidnas are commonly known as ‘spiny ant-eaters’, but long-beaked echidnas (Zaglossus spp.) do not eat ants, whereas short-beaked echidnas (Tachyglossus aculeatus) eat other invertebrates as well as ants. The differences in skull morphology between short- and long-beaked echidnas are related to the differences in their diets, and I tested the hypothesis that there would be differences in beak length of short-beaked echidnas from populations with different diets. Published data on diet from echidnas from different parts of Australia show that echidnas from arid and semi-arid areas (subspecies acanthion) and Kangaroo Island (subspecies multiaculeatus) principally eat ants and termites, whereas the main dietary items of echidnas from south-eastern Australia (subspecies aculeatus) and Tasmania (subspecies setosus) are ants and scarab larvae. Using museum specimens and photographs I measured skull dimensions on echidnas from different parts of Australia: acanthion and multiaculeatus have narrower skulls and shorter beaks than aculeatus and setosus, with setosus being the only Australian subspecies where beak length exceeds cranium length. Australian short-beaked echidnas fall into two groups: aculeatus and setosus from the wetter east and south-east, which eat ant and scarab larvae, and the arid and semi-arid zone acanthion and multiaculeatus, with shorter, narrower skulls, and which eat ants and termites.

Highland vs. lowland craniometry in Andean South America: An Ecuadorian case study

Previous research on crania of pre-Columbian Peru has demonstrated a significant difference between coastal lowland and Andean highland populations in cranial length. This has not been examined for other Andean countries. In this study, we examined 14 colonial-era crania from the highland city of Cuenca, Ecuador, and compared them with pre-Columbian crania from lowland Ecuador, and highland and lowland Peru to see if the highland-lowland distinction held true for Ecuador. Eight craniometrics from 153 individuals were used in principal component analysis, indicating that the majority of the Cuenca crania were similar to other highland groups. Logistic regression analysis confirmed that 12 out of the 14 Cuenca individuals were native highlanders. These demonstrate that cranial morphology in Ecuador follows the same highland vs. lowland pattern as previously found in Peru. Even after Spanish colonialism, the Andes Mountains provided a barrier for migration and gene flow.

Dental-craniofacial Characteristics of Southern Vietnamese People with Well-balanced Face on Cephalometric Films and Its Comparison with Caucasians and Northern Vietnamese Population.

Objectives:The objective of this study was to evaluate the dental-craniofacial measurements of the Southern Vietnamese people aged 18 to 25 with well-balanced face on cephalometric films.Materials and Methods:This cross-sectional study included 60 cephalometric tracings of students (30 males, 30 females). The cephalometric measurements were made on 34 angles, 26 distances, and 4 ratios of skeletal, dental, and soft tissue cephalometric analysis. The mean and standard deviation (SD) of the dental-craniofacial measurements were calculated and compared among male and female subjects and with Caucasian and the Northern Vietnamese population.Results:Among the Southern Vietnamese cephalometric tracing samples, the majority of the linear measurements were smaller in female than in male, while the angular and ratio measurements showed no significant difference. When compared with Caucasians, the cranial fossa lengths, the vertical facial heights, the lengths of maxilla and mandible, and the facial convexity of the Southern Vietnamese people were significantly smaller (P < 0.01), while the upper and lower incisors protrusion, and lip protrusion were larger (P < 0.01). The maxillary and mandibular protrusions, and mandibular rotational patterns were similar between these two groups. When compared with the Northern Vietnamese population, the mandibular plane angle and the upper and lower incisor protrusion of the Southern Vietnamese people were significantly larger (P < 0.05).Conclusions:The dental-craniofacial measurements of the Southern Vietnamese people were different among male and female, and different than those of Caucasians and Northern Vietnamese population. Such differences should be taken into account when considering orthodontic and orthognathic treatment strategies.

Dentofacial and skeletal pattern in African descendants from southeastern Brazil: clinical prospective study.

ABSTRACTObjective: The aim of this study was to evaluate characteristics of African-Brazilians young adults with excellent dental occlusion, including bimaxillary protrusion; compare them to European-American Caucasian standards, and determine whether there is sexual dimorphism in the display of this phenotype. Methods: Lateral cephalometric radiographs were obtained from 43 African-Brazilians within military personnel (28 males and 15 females, average age 22.4 ± 3.4 years) with normal occlusion, selected from a group of 394 volunteers. Thirty-one angular and linear measurements were evaluated. Student’s t-test for independent samples was used to compare results with those established by European-American standards, previously described in the literature. Results: Considering the dentoalveolar pattern, seven angular and six linear measurements showed statistically significant differences (p< 0.001) when compared to Caucasian cephalometric standards. African-Brazilians’ subjects showed lower cranial base angle (SNAr = 119.87 ± 5.66º) and anterior cranial base length (SN-distance = 68.63 ± 4.50 mm) (p< 0.001). The maxilla (SNA = 88.51 ± 3.23º) and the mandible (SNB = 85.06 ± 3.24º) were protruded in relation to the SN line (p< 0.001). Sexual dimorphism was significant for L1.NB (degrees) (p< 0.01), and interincisal angle (U1.L1) (p< 0.05). Conclusion: African-Brazilian young adults presented differences regarding dental and craniofacial characteristics, when compared to European-American norms. It can be stated that Caucasian cephalometric norms should not be applied to African-Brazilian faces.

A descriptive morphometric approach to the skull in Red fox (Vulpes vulpes) of Egypt

Craniofacial anatomy is essential to understand the locative relationships of organs in specific region of each species. This study was aimed to investigate morphometric parameters of the skull of the Red fox of Egypt. Thirteen skulls of about 2.5-4 years-old male Red fox were carefully processed using standard method. Altogether, 29 different osteometric measurements including 7 different indices were estimated. The average total length and width of the skull in the Red fox were 17.64 ± 2.68 cm and 8.73 ± 1.76 cm, respectively, with cephalic index of 49.27 ± 3.42. The cranial length of the Red fox’s skull was about two-fold of its width, with cranial capacity of 49.54 ± 3.75 cc, as well as cranial and basal indices were 49.87 ± 3.96 and 30.97 ± 2.33, respectively. The foramen magnum width was higher than its height, with foramen magnum index of 71.52 ± 3.86. The cranial length of the Red fox’s skull was higher than the facial length, with facial index of 62.70 ± 4.01. The orbital length was higher than the orbital width, and the interorbital distance was wider caudally and narrower in the middle, with orbital capacity and orbital index of 9.34 ± 0.17 cc and 97.87 ± 5.22, respectively. In conclusion, measured osteometric parameters of the Red fox’s skull will provide baseline anatomy information on the skull morphometry, which is necessary for comparative anatomy and clinical veterinary practice. The findings reported here will assist other clinical studies conducting on the Red fox’s head.

Возрастные изменения головного указателя и размеров таламусов у мезоцефалов

Objective: to identify the pattern of age-related changes in the cerebral index and to determine the dynamics of trans-verse and longitudinal thalamic dimensions in mesocephalians according to magnetic resonance imaging. Material and methods. The data of magnetic resonance imaging of the brain of 78 people (37 men and 41 women) were analyzed. Depending on the age, all the subjects were divided into two groups. Group I consisted of 43 people (21 men and 22 women) of the first period of adulthood (29.19±0.73 years), group II - 35 people (16 men and 19 women) of senile age (78.97 ± 0.61 years). The cranial width index and cranial length index were calculated from the outermost protruding points on the axial section in 3D reconstruction mode. Morphometric examination of the thalamus included determining its linear dimensions in the axial plane: transverse (distances from the most distant medial and lateral points) and longitudinal (distances from the most distant anterior and posterior points). Results. Analysis of head index values revealed their statistically significant prevalence in men compared to women in the first period of adulthood (p&lt;0.01). In old age, there were no sex differences, but there was a tendency for the values of the head index to prevail in men compared to women (p&gt;0.05). Transverse and longitudinal dimensions of the thalamus in both hemispheres were found to be predominant in both males and females in the first period of adulthood in comparison with old age (p&lt;0,01). When comparing the thalamic dimensions of the right and left hemispheres, both in the first period of adulthood and in senile age, no statistically significant differences in parameters were found, but there was a tendency for their predominance in the left thalamus (p&gt;0.05). Conclusion. The results obtained in this study add to the information available in the scientific literature on age-related changes in the cerebral index as well as on the morphometric characteristics of the thalamus in both sexes during the first period of adulthood and in old age, making it possible to implement a personified approach in medical practice as well as to use these data in further clinical and basic research.

Assessment of Gender Dimorphism Using Cephalometry in Iranian Population

Abstract&#x0D; Cephalic indices is useful for evaluating racial and gender differences. In this study, we aimed to asses Gender Dimorphism Using cephalometry in the Iranian Population. Different variables like cranial length (CL), cranial width (CW), and cranial height (CH) were measured and cranial index (CI), cranial capacity (CC), and brain weight of 400 Iranian volunteers were calculated. Data were analyzed by means of SPSS 22.0.&#x0D; There were significant differences in the mean value of all nasofacial parameters (P&lt;0.05). The highest sensitivity and specificity to predict the gender dimorphism were related to FL and FW (0.990 and 0.97) and (0.970 and 0.94), respectively. Considering the differences between male and female cranial structures, can be useful in forensic medicine and designing neurosurgical and ergonomic instruments in addition, to distinguish and discover the gender of the humans related to the many years ago.

Interrater and Intrarater Reliability of Cranial Anthropometric Measurements in Infants with Positional Plagiocephaly.

(1) Background: anthropometric measurements with calipers are used to objectify cranial asymmetry in positional plagiocephaly but there is controversy regarding the reliability of different methodologies. Purpose: to analyze the interrater and intrarater reliability of direct anthropometric measurements with caliper on defined craniofacial references in infants with positional plagiocephaly. (2) Methods: 62 subjects (<28 weeks), with a difference of at least 5 mm between cranial diagonal diameters. Maximal cranial circumference, length and width and diagonal cranial diameters were measured. Intrarater (2 measurements) and interrater (2 raters) reliability was analyzed. (3) Results: intra- and interrater reliability of the maximal cranial length and width and right cranial diagonal was excellent: intraclass correlation coefficient (ICC) > 0.9. Intrarater and interrater reliability for the left cranial diagonal was excellent: ICC > 0.9 and difference in agreement in the Bland-Altman plot 0.0 mm, respectively. Intrarater and interrater reliability for the maximal cranial circumference was good: differences in agreement in Bland-Altman plots: intra: −0.03 cm; inter: −0.12 cm. (4) Conclusions: anthropometric measurements in a sample of infants with moderate positional plagiocephaly have shown excellent intra- and interrater reliability for maximal cranial length, maximal cranial width, and right and left cranial diagonals, and good intra- and interrater reliability in maximal cranial circumference measurement.

An anatomical study of the dorsal and ventral nasal conchal bullae and middle nasal conchae in normal Shetland ponies: Computed tomographic anatomical and morphometric findings.

Equine paranasal sinuses are susceptible to inflammation. Insufficient drainage through the nasal passages and meatus may lead to the accumulation of inspissated purulent discharge. Particularly in ponies, these anatomical structures are suspected to be relatively small. To date, there are no reports consideringthe morphology of nasal conchal bullaein small horse breeds such as Shetland ponies. The aim of the present study was to evaluatethe size of the conchal bullae and the medial nasal conchae of Shetland ponies and their relation to the skull dimension using computed tomography. Reconstructed images of healthy adult heads of Shetland ponies were used. Linear skull measurements as well as two cranial indices of the head dimensions were taken. Length, width and height of the dorsal and ventral conchal bullae and the medial nasal conchae were measured in relation to the skull and compared with the data of skulls of large breed horses. The anatomical proportions of pony heads were characterized by a smaller cranial index and a greater nasal index than those of large breed horses. Shetland ponies showed a longer cranial length compared with the nasal length. Heads are consistently smaller, and the relationship of the bullae to the head length was also smaller than those measured in large breed horses. A negative correlation between the head and bullae size was found. In conclusion, this study suggests that Shetland ponies have distinguishing proportions of the head. These findings are relevant for clinical examinationand surgical treatment of equine sinus diseasein those breeds.

In-plane ultrasound-guided peribulbar block in the dog: an anatomical cadaver study

ObjectiveTo describe a novel in-plane ultrasound (U/S)-guided temporal approach to peribulbar block in dogs. Study DesignProspective experimental cadaver study. AnimalsA group of 10 Beagle cadavers. MethodsAfter describing the U/S anatomy, peribulbar injection was performed bilaterally in 10 thawed Beagle cadavers by two randomly assigned operators. A 5–8 MHz microconvex U/S probe was positioned caudal to the orbital ligament in the longitudinal plane. Using an in-plane technique, methylene blue dye was injected in five dogs (10 eyes total), while methylene blue dye and iohexol contrast mixture (50:50) were injected in the remaining five dogs. Injection volume was 0.2 mL cm−1 of cranial length. A computed tomography (CT) scan was performed on dogs injected with dye and contrast to identify spread of contrast. Dissection to visualize dye spread in the orbit was performed in all dogs. Injection success was defined as spread of contrast into the peribulbar space. The pattern of distribution of contrast-dye was also assessed. Comparisons between operator and bilateral injections were assessed using a Student t test (p < 0.05). All other data are reported as number (n/N) and percentage (%). ResultsPeribulbar spread was noted in 19/20 injections (95%) on dissection. CT imaging (five dogs) illustrated peribulbar contrast spread in 9/10 injections (90%), with mixed peribulbar/retrobulbar spread for the remaining injection. Contrast was present at the rostral alar foramen in 4/10 (40%) injections, orbital fissure in 5/10 (50%), oval foramen in 1/10 (10%), maxillary nerve in 3/10 (30%) and intracranial in 5/10 (50%). Coverage of the maxillary nerve was noted on 3/20 (15%) injections on dissection. No further dye spread was noted. Conclusions and clinical relevanceThis technique demonstrated peribulbar spread of injectate in 100% of injections for the 10 canine cadavers studied. Further studies are required to evaluate this technique clinically.

Ocular echobiometry and head measurements in Jersey cattle from different age groups.

A longitudinal study was conducted to identify the morphological development of eyes and head of Jersey cattle at different ages. A total of 48 healthy Jersey cattle, 1 to 58months of age, were included in the study. Ophthalmologic examinations were performed to identify healthy cattle to form the age groups: GI (1- to 11-month-old), GII (16- to 24-month-old) and GIII (25- to 58-month-old). The animals were physically restrained and examined by transcorneal ultrasound of both eyes; the axial length (AxL), corneal thickness (CO), lenticular thickness (L), depth of the anterior (AC) and vitreous (VC) chambers were evaluated. The cranial measurements obtained included the total, cranial, and nasal lengths and widths. Subsequently, the cephalic index (CI) was calculated. The AxL (GI: 2.83cm; GII: 3.16cm; GIII: 3.24cm), AC (GI: 0.44cm; GII: 0.53cm; GIII: 0.53cm), L (GI: 0.88cm; GII: 1.01cm; GIII: 1.04cm) and VC (GI: 1.44cm; GII: 1.55cm; GIII: 1.59cm) increased (p≤.001) according to age, but the CO (GI: 0.07cm; GII: 0.08cm; GIII: 0.08cm) (p>.05) did not. The total length (GI: 30.83cm; GII: 43.29cm; GIII: 44.15cm), cranial length (GI: 18.11cm; GII: 23.82cm; GIII: 22.69cm), nasal length (GI: 12.72cm; GII: 19.47cm; GIII: 21.46cm) and nasal width (GI: 26.22cm; GII: 33.82cm; GIII: 34.00cm) increased (p<.001), and the CI (GI: 85.66cm; GII: 78.15cm; GIII: 77.02cm) decreased (p<.001). The AxL correlated positively (p<.001) with the cranial length and width and negatively with the CI (p>.05). The ocular biometry of Jersey cattle correlates with their cranial measurements at different ages. With increasing age, the eyes and the head grow, establishing growth curves similar to those of other mammals.

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.

Craniofacial morphology in down syndrome: a systematic review and meta-analysis.

The aim of this study was to evaluate the craniofacial cephalometric characteristics of individuals with Down syndrome (DS), comparing them with healthy subjects. An electronic search was made in Pubmed, Embase, Lilacs, Scopus, Medline and Web of Science without imposing limitations on publication date or language. Studies were selecting following the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) statement. The PECO acronym was applied as follows: P (population), individuals with DS; E, (exposition) diagnosis of DS; C (comparison), individuals without DS; O (outcomes) craniofacial characteristics based on cephalometric measurements. Independent reviewers performed data extraction and assessed the methodological quality of the articles using the Newcastle–Ottawa Quality-Assessment-scale. Seven case–control studies were included in meta-analysis. Given the variability of the cephalometric measurements used, only those that had been reported in at least three or more works could be included. Anterior cranial base length (SN), posterior cranial base length (SBa), total cranial base length (BaN), effective length of the maxilla (CoA), sagittal relationship between subspinale and supramentale (ANB), anterior facial height (NMe), and posterior facial height (SGo) values were significantly lower in the DS population than among control subjects. No significant differences were found in sagittal position of subspinale relative to cranial base (SNA) and sagittal position of supramentale relative to cranial base (SNB). Summarizing, individuals with DS present a shorter and flatter cranial base than the general population, an upper jaw of reduced sagittal dimension, as well as a tendency toward prognatic profile, with the medium third of the face flattened and a reduced anterior and posterior facial heights.

The role of postnatal estrogen deficiency on cranium dimensions.

The aim of this study was investigate the cranium dimensions of adult female rats, who suffered estrogen deficiency during the prepubertal stage, to assess the impact of estrogen deficiency on craniofacial morphology. Twenty-two female Wistar rats were divided into ovariectomy (OVX) (n = 11) and sham-operated control (n = 11) groups. Bilateral ovariectomy were performed in both groups at 21 days old (prepubertal stage), and rats were euthanized at an age of 63 days (post-pubertal stage). Micro-CT scans were performed with rat skulls, and the cranium morphometric landmark measurements were taken in the dorsal, lateral, and ventral view positions. Differences in measurements between the OVX and sham control groups were assessed using t test with an established alpha error of 5%. The measures of the rats' skull showed that the inter-zygomatic arch width and anterior cranial base length were significantly larger in OVX group (p = 0.020 and p = 0.050, respectively), whereas the length of parietal bone was significantly higher in the sham group (p = 0.026). For the remaining measurements no significant differences between groups were detected (p > 0.05). This study provides evidence that ovariectomized rats had alterations in cranial bone dimensions, demonstrating that estrogens during puberty are important for skull morphology. To understand the role of estrogen on the postnatal cranium development will impact the clinical diagnose and therapy during childhood and adolescence.

Anteroposterior length of the maxillary complex and its relationship with the anterior cranial base.

To use both absolute anteroposterior maxillary complex length (APMCL) and relative APMCL to investigate the relationship between the maxillary complex, its individual bony segments, and their association to the anterior cranial base. In addition, the relationship between length and position of the maxillary complex was analyzed. Sixty human skulls were analyzed using cone beam computed tomography. The maxillary complex length was measured between anterior and posterior nasal spine (ans-pns), and the average was used as the cut-off to identify a high- and a low-length group based on absolute APMCL. The length ratio between the maxillary complex and the anterior cranial base (ans-pns/SN) was used to identify the two groups based on relative APMCL. The anterior cranial base length and the lengths of the maxillary complex bones were compared between the high- and low-length groups. Based on absolute APMCL, individuals with shorter maxillary complex had shorter anterior cranial base (P = .003), representing normal proportions. Based on relative APMCL, individuals with shorter maxillary complex had longer anterior cranial base and vice versa (P = .014), indicating disproportions. Individuals with shorter maxillary complex exhibited shorter maxilla (Δ = -1.5 mm, P = .014). When skeletal deformity of the midface is suspected, individual disproportions in the anteroposterior length of the maxillary complex in relation to the anterior cranial base (relative measurements) should be assessed through radiological imaging. A shorter maxillary complex may be associated with a shorter maxilla, and not with a shorter premaxilla or palatine bone.

Racial Disparity of Crouzon Syndrome in Skull and Orbit Morphology, and Their Spatial Relationships

BACKGROUND: Racial disparity in pathological consequences in skull and orbit growth may impact the treatment plan for different patient populations. This study explores skull anatomy for potential differences between Asian and Caucasian cranial morphology in Crouzon syndrome. METHOD: Ninety-one computed tomographic scans were included (Asian Crouzon, n = 12; Asian controls, n = 22; Caucasian Crouzon, n = 16; Caucasian controls, n = 41), and measured using Mimics and 3-matics software. Unique cephalometric measurements related to the orbit were designed. RESULTS: 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 with 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). The orbital roof anteroposterior length of Caucasian Crouzon syndrome patients was shortened by 4.03 mm (P = 0.009) compared with Caucasian controls. However, this dimension in Asian patients developed normally. The orbital anteroposterior floor length significantly reduced in both Asian and Caucasian Crouzon syndrome patients, to a similar extent. The medial horizontal angle of single orbit was narrower in Asian patients, compared with Asian controls (19.24°; P = 0.002), yet only insignificantly reduced in Caucasian patients. The visual axes of Caucasian Crouzon syndrome patients had more inferior rotation, by 5.21° (P = 0.005) than in Caucasian controls but did not achieve a statistically significant difference in other comparison pairs. A widened ethmoid sinus is the major shortening in the restricted orbit cone angle in Asian Crouzon syndrome patients, while statistically significant widening of the sphenoid is noted only in Caucasian patients. CONCLUSION: The influence of Crouzon syndrome on cranial and orbital malformation is race influenced. Asian Crouzon patients developed more kyphotic basicranium evaluated intracranially, whereas Caucasian Crouzon patients developed more widened lateral pterygoid bones. The unaffected orbital roof length and shortened orbital floor in Asian Crouzon syndrome patients indicates the Lefort III osteotomy probably is more beneficial in this group of patients than in monobloc advancement.

Using regression tree analysis to determine size class intervals and sexual dimorphism in the Morelet's crocodile Crocodylus moreletii

Assignment of Morelet's crocodile Crocodylus moreletii individuals into size groups or classes based on ecological and morphological similarities has not yet been associated with species‐specific ontogeny related changes. Age or size of first reproductive behavior is not precisely known for C. moreletii, but differences in allometric patterns and relative cranial size between juveniles and adults might be used as an indicator of sexual maturity. In this study, a regression tree analysis was used to investigate the relationship between age and body size in 1266 crocodiles by using both simple and generalized linear models, with gender and origin (captivity or wild) as factors. Total length (TL), snout–vent length (SVL) and cranial length (CL) were used as predictor variables and the logarithm of body mass as the response variable. Four length intervals with well‐defined thresholds (514, 899 and 1497 mm of TL) were established using all three predictors (TL, SVL and CL). Relationship between SVL and TL was described, and a strong positive relationship (r2 = 0.98), unaffected by crocodile gender, was observed. The observed CL–TL and CL–SVL relationships were also positive but significantly different between males and females (p &lt; 0.001) and length interval classes (p = 0.01). These results suggest that our estimated size thresholds seem to correspond to important ontogenetic changes in C. moreletii and that sexual maturity is closely related to size in this species, where sexual dimorphism in body length occurs, particularly in large individuals (size group IV).

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.

Sex determination by basion-nasospinale length and cranial base length in dry human skull bones - A morphometric study

Sex determination by basion-nasospinale length and cranial base length in dry human skull bones - A morphometric study