Basal Skull Length Research Articles

Craniofacial morphology in Obstructive Sleep Apnea patients.

To evaluate the correlation between cephalometric skeletal parameters and Obstructive Sleep Apnea syndrome (OSAs) severity, in adult patients with OSAs. One hundred patients (94 males,6 females mean age 59,3) with diagnosis of OSAs were retrospectively enrolled. Each patient received Home Sleep Apnea Testing (HSAT) and latero-lateral radiograph. Eight cephalometric parameters (cranial deflection angle, saddle angle, articular angle, divergence angle, cranial base angle, skull base length, mandibular length, maxilla length) were analyzed and then related to Apnea/Hypopnea Index (AHI) and to the Oxygen Desaturation Index (ODI), recorded by HSAT. A Spearman's rho correlation test between cephalometric measurements and HSAT indices was performed. Statistical significance was set at p< 0.05. A negative statistically significant correlation was found between mandibular length (Condilion-Gnathion distance) and AHI (rho= -0,2022; p<0,05) and between maxilla length (Ans-Pns) and AHI (rho= -0,2984; p<0,01) and ODI (rho= -0,2443; p<0,05). A statistically significant correlation was also observed between the divergence angle (S-N^Go-Me) and AHI (rho=0,2263; p<0,05) and between cranial deflection angle (Fh^NBa) and AHI (rho=0,2212; p<0,05) and ODI (rho=0,1970; p<0,05). The OSAs severity may be related to certain predisposing features in craniofacial morphology, such as maxillary and mandibular length, divergence and cranial deflection. Key words:OSAs, Home Sleep Apnea Testing, AHI, ODI, Cephalometry, Airway.

The relationship between frontal sinus dimensions and skeletal malocclusion.

The aim of this retrospective research is to compare frontal sinus dimensions in skeletal Class I, skeletal Class II, and skeletal Class III individuals and to evaluate the relationship of these dimensions with anterior skull base length and some cephalometric values. In this research, we used lateral cephalometric radiographs of 60 people aged 17 to 25. In individuals with skeletal Class I malocclusion, skeletal Class II malocclusion due to mandibular insufficiency, and skeletal Class III malocclusion due to mandibular excess, measurements of frontal sinus length and height as well as S-N, Co-A and Co- Gn lengths, ANB0, FMA0, SN-GoGn0 angles values were performed. The length between the highest point and the lowest point of the frontal sinus was calculated as the height of the frontal sinus, and the length between the most anterior and the most posterior points of the frontal sinus was calculated as the length of the frontal sinus. The frontal sinus length and height were found to be higher in skeletal Class III individuals than in skeletal Class I and skeletal Class II individuals, however, there was no significant difference between skeletal Class I and Class II individuals. The increase in frontal sinus height and length correlated positively with the decrease in the ANB angle and the increase in the SN and Co-Gn lengths. The dimensions of the frontal sinus may be an indicator for the remaining mandibular growth potential.

A Gulliver Scaloposaurus (Therapsida, Therocephalia) from the Katberg Formation of South Africa and its implication for Lilliput assemblages during the Early Triassic recovery

‘Scaloposaurs’ represent a wastebasket taxon of small therocephalian therapsids once believed to be close to the evolutionary ancestry of mammals. The group is now thought to be made up of mostly paedomorphic or juvenile therocephalians belonging to various families. Here, a new large therocephalian is described from the Early Triassic Lystrosaurus declivis Assemblage Zone (AZ) on the farm Donald 207 (formerly ‘Fairydale’) in South Africa's Karoo Basin, an historic fossil locality. The new specimen consists of a mostly articulated skull and anterior postcranial skeleton, but with a slightly crushed rostrum, requiring micro-computed tomography (μCT) to virtually restore the diagnostic palate morphology. Apomorphic features including a bony maxillovomerine bridge, two small maxillary precanines, and at least eight or nine upper postcanines—are consistent with the genus Scaloposaurus. However, linear dimensions of the new specimen (basal skull length 110 mm) greatly exceed others, being 84% larger than the previous largest Scaloposaurus specimen. Our discovery of the largest Scaloposaurus reveals distinctive subadult morphology in the genus and underscores hypothesized plasticity in growth patterns of Permo-Triassic therapsids gleaned from histologic analysis. Nevertheless, mixed-age theriodont assemblages are occasionally documented in the Lystrosaurus declivis AZ, and fully-grown specimens continue to be remarkably rare in the recovery fauna following the Permo-Triassic mass extinction. Importantly, this interval has also been characterized by apparent short-term reductions in body sizes of fossil assemblages (Lilliput phenomena). These findings are consistent with our recent hypothesis that, unlike in preceding time intervals, juvenile excess mortality was relatively high during the Early Triassic extinction recovery.

Variation in brain volume in nine populations and three taxa of the African striped mouse Rhabdomys.

Brain size can vary between populations in different environments because of different selection pressures on behaviours, such as learning and memory, related to spatial, social and environmental differences. We investigated the variation in total and broad-scale regional brain size in the murid rodent genus Rhabdomys from different environments. We assessed taxon-, population- and sex-level differences in total and regional brain volume in three populations each of three taxa (arid-occurring Rhabdomys pumilio and mesic-occurring Rhabdomys dilectus chakae and R. d. dilectus) originating across southern Africa. We μCT-scanned crania obtained from museums in South Africa and used digital software to create endocasts and extract total endocranium and regional volumes: olfactory bulb, anterior cerebrum, posterior cerebrum, cerebellum volume and petrosal volume. Total endocranial volume scaled with basal skull length and all-region volumes scaled with total endocranial volume. We found taxon-, and population-level differences in total endocranial volume. Relative anterior and posterior cerebrum volume did not differ significantly between taxa or populations, but relative cerebellum volume was larger in arid populations than mesic populations. Relative olfactory bulb volume was larger in mesic R. dilectus than in the R. pumilio, but petrosal lobule volume was larger in R. pumilio populations than in R. dilectus. Males had larger total endocranial volumes than females. Drivers of larger total endocranial volumes in R. pumilio are not immediately clear from our results. Environmental seasonality of food availability, cognitive buffering and locomotion may all correlate with total endocranial volume size, whereas the influence of sociality cannot be excluded. The environment and degree of semi-arboreality are likely driving variation in cerebellum, olfactory bulb and petrosal lobule volumes.

Tooth replacement in the non-mammalian cynodont Cynosaurus suppostus (Therapsida) from the late Permian of South Africa

ABSTRACT Five specimens of the late Permian cynodont Cynosaurus suppostus, inferred to represent an ontogenetic growth series, were imaged using X-ray microtomography in order to determine the pattern of tooth replacement for the species. Due to the small sample size, and damage to the rostrum in several specimens, replacement patterns of the incisors could not be accurately determined. Evidence supporting the presence of two maxillary canine loci in a juvenile Cynosaurus is presented. Replacement of the mandibular canines ceased at a basal skull length of ∼88 mm, whereas replacement of the maxillary canines ceased at a basal skull length of ∼90 mm. The final canine generation to erupt in both the maxillae and mandible had open-rooted apices. An alternating pattern of replacement is described for the maxillary and mandibular postcanine series. Postcanine replacement generations in the maxilla are seemingly separated by two tooth loci, whereas in the mandible replacement activity occurs at alternating loci. Cessation of replacement in the first maxillary postcanine locus (PC1) is synchronized with the eruption of the replacement tooth in the third locus (PC3). This cessation of replacement at PC1 results in a distal migration of the entire maxillary postcanine series. This pattern provides possible evidence for a finite number of replacement generations occurring at the active PC1. There appear to have been two replacement cycles per postcanine locus in Cynosaurus, which is a lower number of total replacements per postcanine locus than previously estimated for the Early Triassic basal cynodont Thrinaxodon liorhinus.

Tooth replacement patterns in the Early Triassic epicynodont Galesaurus planiceps (Therapsida, Cynodontia).

Sixteen specimens of the Early Triassic cynodont Galesaurus planiceps (including eight that were scanned using micro-computed tomography) representing different ontogenetic stages were assembled to study the dental replacement in the species. The growth series shows that the incisors and postcanines continue to develop and replace, even in the largest (presumably oldest) specimen. In contrast, replacement of the canines ceased with the attainment of skeletal maturity, at a basal skull length of ~90 mm, suggesting that Galesaurus had a finite number of canine replacement cycles. Additionally, the functional canine root morphology of these larger specimens showed a tendency to be open-rooted, a condition not previously reported in Mesozoic theriodonts. An alternating pattern of tooth replacement was documented in the maxillary and mandibular postcanine series. Both postcanine series increased in tooth number as the skull lengthened, with the mandibular postcanine series containing more teeth than the maxillary series. In the maxilla, the first postcanine is consistently the smallest tooth, showing a proportional reduction in size as skull length increased. The longer retention of a tooth in this first locus is a key difference between Galesaurus and Thrinaxodon, in which the mesial-most postcanines are lost after replacement. This difference has contributed to the lengthening of the postcanine series in Galesaurus, as teeth continued to be added to the distal end of the tooth row through ontogeny. Overall, there are considerable differences between Galesaurus and Thrinaxodon relating to the replacement and development of their teeth.

Retrognathic maxilla in individuals born with oral clefts is due to intrinsic factors and not only due to early surgical treatment

To determine if the skeletal form of individuals born with oral clefts was associated with maxillary position. Lateral cephalometric radiographs of 90 individuals 8 to 12 years old born with or without cleft lip and palate paired by age and sex were used. Skull base length, cranial base angle, cranial deflection angle, and maxillary skeletal length and position were studied. Also, mandibular skeletal length and position, lower anterior facial height, and dental position were defined. Individuals were divided into three groups: 30 individuals born with cleft lip and palate with Class III malocclusion (UCLP Class III), 30 individuals born with cleft lip and palate with Class I malocclusion (UCLP Class I), and 30 individuals born without cleft lip and palate with Class III malocclusion (non-cleft Class III). When comparing the UCLP Class III group with the UCLP Class I group, there were differences in maxillary position (P < .001) and mandibular position (P = .004) found. No differences were found when comparing the UCLP Class III group with the non-cleft Class III group. There are intrinsic factors that affect craniofacial morphology of individuals born with cleft lip and palate.

The paleobiology and paleoecology of South African Lystrosaurus.

Lystrosaurus was one of the few tetrapods to survive the end-Permian mass extinction (EPME), the most catastrophic biotic crisis in Phanerozoic history. The significant increased abundance of this genus during the post-extinction Early Triassic recovery period has made Lystrosaurus an iconic survivor taxon globally and ideal for studying changes in growth dynamics during a mass extinction. There is potential evidence of a Lilliput effect in Lystrosaurus in South Africa as the two Triassic species that became highly abundant after the EPME are relatively smaller than the two Permian species. In order to test this hypothesis a detailed examination of the body size and life history of Permo-Triassic Lystrosaurus is required. In this study, the basal skull length and growth patterns of the four South African Lystrosaurus species from the Karoo Basin, L. maccaigi, L. curvatus, L. murrayi and L. declivis, were examined using cranial measurements and bone histology. The basal skull length measurements show that the Triassic species are smaller than the Permian species and supports previous studies. The osteohistology examination of all four species reveal rapidly forming fibrolamellar bone tissues during early to mid-ontogeny. Growth marks are common in L. maccaigi and L. curvatus, but rare and inconsistent in the purely Triassic L. murrayi and L. declivis. The inconsistency of the growth marks in these latter two taxa suggests the presence of developmental plasticity. This feature may have been advantageous in allowing these species to alter their growth patterns in response to environmental cues in the post-extinction Early Triassic climate. An overall transition to slower forming parallel-fibered bone is observed in the largest individuals of L. maccaigi, but absent from the limb bones of the other species. The absence of such bone tissue or outer circumferential lamellae in L. curvatus, L. murrayi and L. declivis indicates that even the largest collected specimens do not represent fully grown individuals. Although L. murrayi and L. declivis are smaller in size, the lack of a growth asymptote in the largest specimens indicates that adult individuals would have been notably larger and may have been similar in size to large L. maccaigi and L. curvatus when fully grown. Thus, the previously described Lilliput effect, recognized by some authors in the Karoo fossil record (such as the therocephalian Moschorhinus kitchingi), may be a product of high juvenile excess mortality in the Triassic rather than a strict “dwarfing” of Lystrosaurus species. The lifestyle of Lystrosaurus was also re-examined. Although previous studies have proposed an aquatic lifestyle for the genus, the similar morphology and bone microanatomy to several other large terrestrial Permo-Triassic dicynodonts supports a fully terrestrial mode of life.

A new large cynodont from the Late Permian (Lopingian) of the South African Karoo Basin and its phylogenetic significance

AbstractThe Karoo Basin of South Africa has the best global record of Lopingian (Late Permian) non-mammaliaform cynodonts, currently represented by five species. We describe Vetusodon elikhulu gen. et sp. nov., documented by four specimens from the Daptocephalus Assemblage Zone. With a basal skull length of ~18 cm, it is the largest Lopingian cynodont and is also larger than Induan representatives of the group. Vetusodon elikhulu has a cranial morphology that departs notably from that previously documented for Permo-Triassic cynodonts. It features a short and extremely wide snout, resembling that of the contemporaneous therocephalian Moschorhinus, and has large incisors and canines that contrast with the small unicusped postcanines, suggesting a more important role of the anterior dentition for feeding. The dentary is extremely long and robust, with the posterior margin located closer to the craniomandibular joint than in other Lopingian and Induan cynodonts (e.g. Thrinaxodon). The secondary palate morphology of V. elikhulu is unique, being short and incomplete and with the posterior portion of the maxilla partly covering the vomer. A phylogenetic analysis suggests that V. elikhulu is the sister taxon of Eucynodontia and thus the most derived of the Lopingian to Induan cynodonts yet discovered.

Original Research. Correlation Between Cranial Base Morphology And Various Types Of Skeletal Anomalies

Abstract Background: Previous studies regarding various types of malocclusions have found correlations between the angle of the base of the skull and prognathism. Aim of the study: This cephalometric study sought to investigate the function of the cranium base angle in different types of malocclusion on a group of Romanian subjects. Materials and methods: Forty-four cephalometric radiographs were selected from patients referred to orthodontic treatment. The cephalometric records were digitized, and with the CorelDRAW Graphics Suite X5 software 22 landmarks have been marked on each radiograph. A number of linear and angular variables were calculated. Results: The angle of the base of the skull was found to be higher in Class II Division 1 subjects compared to the Class I group. The cranial base lengths, N-S and S-Ba, were significantly larger in both categories of Class II malocclusion than in Class I patients, but measurements were comparable in Class I and Class III. The SNA angle showed no considerable variation between Class I subjects and the other groups. SNA-SNP was significantly increased above Class I values in Class II Division1 and Class II Division 2 groups. No significant dissimilarities were observed for these lengths between Class I and Class III patients. Conclusions: The angle of the cranium base (S-N-Ba, S-N-Ar) does not have a major role in the progression of malocclusion. In Angle Class II malocclusion the SNA angle is increased, and SNB is increased in malocclusion Class III. The anterior skull base length is increased in Class II anomalies. The length of the maxillary bone base is increased in Class II malocclusions type; in Class III type of malocclusion the length of the mandible bone is increased.

Cranial Ontogeny of the Early Triassic Basal Cynodont Galesaurus planiceps.

Ontogenetic changes in the skull and mandible of thirty-one specimens of Galesaurus planiceps, a basal non-mammaliaform cynodont from the Early Triassic of South Africa, are documented. The qualitative survey indicated eight changes in the craniomandibular apparatus occurred during growth, dividing the sample into three ontogenetic stages: juvenile, subadult, and adult. Changes in the temporal region, zygomatic arch, occiput, and mandible occurred during the transition from the subadult to adult stage at a basal skull length of 90 mm. At least four morphological and allometric differences divided the adult specimens into two morphs, indicating the presence of sexual dimorphism in Galesaurus. Differences include extensive lateral flaring of the zygomatic arches in the "male" morph resulting in a more anterior orientation of the orbits, and a narrower snout in the "female". This is the first record of sexual dimorphism in a basal cynodont, and the first time it is quantitatively documented in a non-mammaliaform cynodont. An ontogenetic comparison between Galesaurus and the more derived basal cynodont Thrinaxodon revealed differences in the timing and extent of sagittal crest development. In Galesaurus, the posterior sagittal crest, located behind the parietal foramen, developed relatively later in ontogeny, and the anterior sagittal crest rarely formed suggesting the anterior fibres of the temporalis were less developed than in Thrinaxodon. In contrast, craniomandibular features related to the masseters became more developed during the ontogeny of Galesaurus. The development of the adductor musculature appears to be one of the main factors influencing skull growth in these basal non-mammaliaform cynodonts. Anat Rec, 300:353-381, 2017. © 2016 Wiley Periodicals, Inc.

Polymorphism of skull proportions in large African barbs Barbus intermedius sensu Banister (Cyprinidae) from Lakes Awasa and Langano (Rift Valley, Ethiopia)

After performing principal component analysis (PCA) of 13 characters (indices) of skulls of large African barbs (Barbus intermedius complex sensu Banister, 1973) from Lakes Awasa and Langano (Ethiopia) distributions of individuals in coordinates BL and PC1 were studied where BL is the basal skull length and PC1 is the first principal component. It is shown that in both the lakes there are groups of barbs whose individual ontogenetic trajectories are situated within separated ontogenetic channels. Separation of the channels is by far less distinct than that of the channels of generalized and specialized forms of barbs from Lake Tana and not correlated with differences in external traits. It is suggested that the revealed polymorphism is connected with food resource partitioning and might serve as a prerequisite of further divergence of sympatric forms of large African barbs.

Ontogeny of the Early Triassic Cynodont Thrinaxodon liorhinus (Therapsida): Cranial Morphology.

The cranial morphology of 68 Thrinaxodon liorhinus specimens, ranging in size from 30 to 96 mm in basal skull length, is investigated using both qualitative and quantitative analyses. From this comprehensive survey, we determined that nine cranial features, including five in the temporal region, separated the sample into four ontogenetic stages. A bivariate analysis of 60 specimens indicated that the skull generally increased in size isometrically, with the exception of four regions. The orbit had negative allometry, a result consistent with other ontogenetic studies of tetrapods, whereas the length of the snout, palate, and temporal region showed positive allometry. The last trend had strong positive allometry indicating that during ontogeny the length of the sagittal crest increased at a much faster rate than the rest of the skull. The large number of changes in the temporal region of the skull of Thrinaxodon may indicate a greater development of the posterior fibres of the temporalis musculature from an early ontogenetic stage. For example, the posterior sagittal crest developed much earlier in ontogeny than the anterior crest that formed in adults, and bone was deposited dorsally creating a unified posterior sagittal crest rather than having a suture that spanned the entire depth of the skull roof. In combination with the isometric height of the zygomatic arch and the almost complete absence of the zygomatic arch angulation, these ontogenetic changes suggest that there was greater development of the temporalis relative to the masseter muscles, indicating a strong posterodorsal movement of the mandible in Thrinaxodon.

Gender Dimorphism of Crania in Young Jordanian Adults: Discriminant Function Analysis Approach for Gender Prediction

Background: Determination of gender using craniofacial characteristics, though made common worldwide, Jordan is still lacking of such investigation. The aim of this study was to develop a gender determination technique for young Jordanian adult population using osteometric data, from c ephalometric images, and discrimina nt function analysis. Methods: A total of 146 randomly selected digital lateral cephalometric radiographs of fully dentate young adult patients were used in the investigation; 47 patients were males and 99 were females. For each lateral cephalometric radiograph 19 craniofacial skeletal landmarks were digitized by one observer using a customized analysis created in Viewbox 4-Cephalometric Software subroutines. Utilizing the digitized landmarks, 18 measurements that comprised 14 linear, three angular and one proportional parameters were carried out. Results: The results demonstrated that, with the exception of the Menton to Gonion distance, i.e. the length of the mandibular body, the mean values of all other parameters of male subjects were statistically significantly larger (P &lt; 0.05) than those for females. Mastoid height was found to be the best single predictor of gender and can provide an accuracy rate of 82.2%. The stepwise method revealed four dimensions (mastoid height, mastoid width, glabella to supraglabellare-nasion distance, and the length of skull base) were found to form the best combination of parameters most precisely to depict the best possible prediction, raising the classification accuracy up to 87.7%. Conclusions: A discriminant function equation specific for Jordanian population has been derived from cranio-mandibular variables. The equation can now be used for a calculable and more precise prediction of gender of Jordanian young adult population. J Curr Surg. 2014;4(3):76-85 doi: http://dx.doi.org/10.14740/jcs241w

Ontogeny of the Early Triassic cynodont Thrinaxodon liorhinus (Therapsida): dental morphology and replacement

ABSTRACT Here for the first time we use micro-computed tomography (μCT) scanning techniques to study dental replacement in the Early Triassic cynodont Thrinaxodon liorhinus. We analyzed five specimens ranging 37–87 mm in skull length using μCT scanning, which were supplemented by detailed anatomical analysis of 48 specimens with a basal skull length of 30–96 mm. Our results indicate that lower postcanines are more numerous and present a more complex morphology than the upper postcanines, even in the same individual; only the lower postcanines have more than three sectorial cusps and a cingular collar on the lingual margin. Complexity of the postcanines increases from the smallest individual to specimens with a skull length of 75 mm, but complexity decreases in larger specimens. Our results confirm the alternate replacement of the postcanines and the posterior migration of the postcanine series (including the loss without replacement of the anterior-most postcanines). Observations point to a posterior-to-anterior replacement wave in lower postcanines, but the evidence is not clear-cut for the upper series. The virtual extraction of functional and replacement teeth permitted us to conclude that in most of the cases the upper canines were replaced anteriorly, whereas lower canines were replaced posteriorly. The presence of two simultaneous replacements of the upper canine tooth was observed in two small juveniles, suggesting a higher rate of canine replacement at a younger age. Incisors also had a sequential replacement pattern, and more replacement teeth were present in medium-sized individuals.

Pride Diaries: Sex, Brain Size and Sociality in the African Lion (Panthera leo) and Cougar (Puma concolor)

The purpose of this study was to examine if differences in social life histories correspond to intraspecific variation in total or regional brain volumes in the African lion (Panthera leo) and cougar (Puma concolor). African lions live in gregarious prides usually consisting of related adult females, their dependent offspring, and a coalition of immigrant males. Upon reaching maturity, male lions enter a nomadic and often, solitary phase in their lives, whereas females are mainly philopatric and highly social throughout their lives. In contrast, the social life history does not differ between male and female cougars; both are solitary. Three-dimensional virtual endocasts were created using computed tomography from the skulls of 14 adult African lions (8 male, 6 female) and 14 cougars (7 male, 7 female). Endocranial volume and basal skull length were highly correlated in African lions (r = 0.59, p < 0.05) and in cougars (r = 0.67, p < 0.01). Analyses of total endocranial volume relative to skull length revealed no sex differences in either African lions or cougars. However, relative anterior cerebrum volume comprised primarily of frontal cortex and surface area was significantly greater in female African lions than males, while relative posterior cerebrum volume and surface area was greater in males than females. These differences were specific to the neocortex and were not found in the solitary cougar, suggesting that social life history is linked to sex-specific neocortical patterns in these species. We further hypothesize that increased frontal cortical volume in female lions is related to the need for greater inhibitory control in the presence of a dominant male aggressor.

Distribution and diversity patterns of Triassic cynodonts (Therapsida, Cynodontia) in Gondwana

Cynodonts are an important component of Triassic tetrapod faunas and are frequently one of the dominant groups. A summary of their record during the Triassic of Gondwana is presented. Cynodonts are represented by 63 species/57 genera in Gondwana with diversification peaks occurring during the Late Anisian (particularly in Africa) and the Carnian of South America and India. Data on the number of faunas of each age and the duration (in millions of years) estimated for these faunas were integrated with cynodont generic diversity values. One of the most important turnovers in cynodonts occurred at the Late Olenekian–Anisian, involving changes in two directions: a) the record of complex bucco-lingually expanded (gomphodont) postcanines, with traversodontid cynodonts already representing an important group at the end of the Anisian; b) the record, particularly during the Anisian, of significantly large-sized cynodonts (e.g. Cynognathus and Diademodon with basal skull length between 30 to 40 cm). Considering that the global maximum peak of cynodont diversity is during the Norian–Rhaetian, the diversity of Gondwanan cynodonts for that time, eight taxa, is remarkably low.

Endoscopic pedicled nasoseptal flap reconstruction for pediatric skull base defects

A prospective study of endoscopic expanded endonasal approaches (EEA) with nasoseptal flap reconstructions revealed anecdotal evidence of less available relative septal length in pediatric patients. Our goal is to use radioanatomic analysis of computed tomography (CT) scans to determine limitations of the nasoseptal flap in pediatric skull base reconstruction and to describe clinical outcomes after using the nasoseptal flap in six pediatric patients. Six pediatric patients who underwent EEA with nasoseptal flap reconstruction were prospectively analyzed for flap coverage and postoperative cerebrospinal fluid (CSF) leak. Fifty maxillofacial CTs of individuals <18 years of age and 10 adult images underwent radioanatomic analysis. Measurements included potential nasoseptal flap dimensions and dimensions required to reconstruct an anterior skull base defect, a trans-sellar defect, and a transclival defect. Measurements were compared to determine if flap size would be sufficient to cover independent EEA defects within different age groups. Two out of three patients <14 years of age had inadequate flap coverage; one had a postoperative CSF leak. Patients >14 years of age had adequate flap coverage. Average potential flap length is less than average anterior skull base length until age 9 years to 10 years, and less than average trans-sellar defect length until age 6 years to 7 years. Septal growth is most rapid between 10 years and 13 years. : The pedicled nasoseptal flap may not be a viable option for EEA reconstruction in children <10 years of age. This flap is a reliable option in patients >14 years of age, as their septums are comparable to adults. Patients 10 years to 13 years of age require careful consideration of facial analysis and preoperative radioanatomic evaluation on an individual basis. Laryngoscope, 2009.

Sexual Dimorphism in Skulls of the Lowland European Bison,Bison Bonasus Bonasus

The research was conducted on 600 (311 male and 289 female) European bison skulls of the Lowland line collected between 1967 and 2006. The specimens came from the bison breeding centre in Białowieza (n = 67) and from the free-ranging population of the Polish part of the Białowieza Forest (n = 533). Two indices best differentiating male and female skulls were selected: one being the quotient of the orbital breadth EctEct and the length of the splanchnocranium StP, the second being the quotient of the neurocranium length BSt and the basal skull length BP. Using these indices we constructed an equation which produced negative values for females and positive values for males; 223 (74%) of the male skulls produced positive values consistent with sex, and 82 (26%) produced negative values, indicating female features. Those features were present mainly in skulls of young males (< 4 years old). 230 (80%) of the female skulls had shapes typical of the female sex, whereas 59 (20%) displayed male features.

Three‐dimensional sonography of prenatal skull base development

To explore longitudinally the development of the fetal skull base using three-dimensional (3D) sonography. Serial 3D sonographic measurements of anterior skull base length, posterior cranial fossa length and skull base angle were made in 126 normal singleton pregnancies at 18-34 weeks of gestation. In a sub-study of 22 pregnancies, intraobserver variability was determined. Regression analysis for repeated measurements was performed by means of the random coefficients model. Results from an earlier publication on brain volume were extended to the total patient cohort. Measurements were technically successful in 69-94% of cases. The coefficient of variation for differences between repeated tests within women was 3.5-7.6% and between repeated analyses of the same recorded volume it was 3.0-5.1%. A statistically significant gestational age-related increase was established for both the anterior skull base length and the posterior cranial fossa length and the skull base angle showed a small but significant flexion of about 6 degrees . A higher increment in posterior cranial fossa length relative to anterior skull base angle was established. A significant quadratic relationship could be established for both anterior skull base length (P < 0.0001) and posterior cranial fossa length (P < 0.0001) but not for skull base angle, relative to brain volume. The reproducibility was acceptable for all fetal skull base measurements. The more pronounced growth in posterior cranial fossa length relative to anterior skull base length is influenced by brain growth. The small flexion of the skull base angle, however, may be caused by other factors. Published by John Wiley & Sons, Ltd.