New materials of plesiacerathere (Perissodactyla, Rhinocerotidae) from the late Early Miocene of Northern China

As a member of Aceratheriinae, the genus Plesiaceratherium in Europe is widely distributed and highly diverse. However, only one species of Plesiaceratherium (i.e., P. gracile) exists in China with a discontinuous distribution range. Recently, we have discovered new materials of Plesiaceratherium in the lower layers of the Zhang'enbao Formation exposed in Miaoerling in Tongxin County, China. The new materials are well-preserved and can be separated from other Plesiaceratherium species by the following combination of features: the long and generally flat skull, with closed frontoparietal crests; the deep nasal notch at the level of P4; the high supraorbital margin, with its anterior margin at the level of the M1/M2 boundary; the medium-sized upper I1, with an oval abraded surface; the semi-molarized upper premolars with the protocone and hypocone joined by a lingual bridge; the strong constrictions of protocone on the upper molars; the absent buccal cingulum on upper cheek teeth; the cheek teeth are covered by cement on the buccal walls; the convex base of mandibular corpus; the inclined backward ramus; and the mandibular foramen above the teeth neck. Based on the combination of characteristics and phylogenetic analysis, we herein establish the new species as Plesiaceratherium tongxinense sp. nov. living in the late Early Miocene. Phylogenetic analysis reveals that P. tongxinense is in the basal position of the genus Plesiaceratherium, providing more detailed morphological characteristics of the plesiaceratheres.

Incidence of anatomical variations according to the International Frontal Sinus Anatomy Classification (IFAC) and their coincidence with radiological sings of opacification

BACKGROUND

The endonasal access to the frontal recess and sinus may be complicated by a variety of anatomical variations. Previous classifications of these variants were characterized by proper names or position information without anatomical reference. The IFAC is intended to simplify the classification of anatomical variations of the frontoethmoidal complex. The aim of this study was to analyse a representative number of sinus CT scans to assess the incidence of anatomical variations according to the IFAC and to compare the results with previous classifications. In addition, the coincidence of complex anatomical variations and radiological sings of opacification was investigated.

METHODOLOGY/PRINCIPAL

Two hundred and forty-nine sinus CT scans were analysed in multiplanar reconstructions. Exclusion criteria were previous operations on the paranasal sinuses, malignant diseases, and an insufficient image quality. All anatomical variants were analysed according to the IFAC criteria. In addition, the coincidence of radiological sings of opacification and the presence of anatomical variations of the frontal recess and sinus were investigated.

RESULTS

The analysis revealed Agger nasi cells in 95% of the CT scans. Supra agger cells (SACs) were detected in 49% and Supra agger frontal cells (SAFCs) in 25% of the data sets. Suprabulla cells (SBCs) were detected in 89% and Supra bulla frontal cells (SBFCs) in 27% of the scans. Supraorbital ethmoid cells (SECs) were detectable in 9% and interfrontal septal cells in 28% of the scans. Despite a partially strong narrowing of the frontal recess, no increased occurrence of radiological sings of opacification could be detected (p > 0.05).

CONCLUSIONS

Anatomical variations in the frontoethmoidal area are very common. According to the IFAC criteria, in 43% of the patients, cells could be detected with pneumatization to or into the frontal sinus. The IFAC is structured more clearly compared to previous classifications due to the anatomical aspect. It represents the most consistent classification regarding surgical planning. Further studies will demonstrate the scientific and clinical value of this classification.

Morphological variation in the anterior cranial fossa

The anterior cranial fossa is an important anatomical landmark in clinical orthodontics consisting of the frontal, ethmoid, and sphenoid bones. The relationships between these bones remain poorly understood. The purposes of the present study were to describe the morphological relationships among the three bones and to discuss the factors contributing to individual variations in adult skulls based on postnatal development. Skulls of 100 Indian adults and 18 Japanese juveniles were observed both macroscopically and using computed tomography images in the median sagittal plane. Three types of relationship were seen among the three bones in adult skulls: (a) a triangular border between ethmoid and sphenoid bones (ethmoid spine), (b) a straight or concave border between ethmoid and sphenoid bones, and (c) frontal bone lying between the ethmoid and sphenoid bones. In the juvenile skull, structures corresponding to those in adults were observed. These three bones comprise the anterior cranial base, each with differing developmental processes, and slight differences in these processes seem to be reflected in the morphological variations seen among adults.

Agreement between cranial and facial classification through clinical observation and anthropometric measurement among Envigado school children

BACKGROUND

To evaluate the agreement between cranial and facial classification obtained by clinical observation and anthropometric measurements among school children from the municipality of Envigado, Colombia.

METHODS

This cross-sectional study was carried out among 8-15-year-old children. Initially, an indirect clinical observation was made to determine the skull pattern (dolichocephalic, mesocephalic or brachycephalic), based on visual equivalence of right eurion- left eurion and glabella-opisthocranion anthropometric points, as well as the facial type (leptoprosopic, mesoprosopic and euryprosopic), according to the left and right zygomatic, nasion and gnation points. Following, a direct measurement was conducted with an anthropometer using the same landmarks for cranial width and length, as well as for facial width and height. Subsequently, both the facial index [euryprosopic (≤80.9%), mesoprosopic (between 81% - 93%) and leptoprosopic (≥93.1%)] and the cranial index [dolichocephalic (index ≤ 75.9%), mesocephalic (between 76% - 81%), and brachycephalic (≥81.1%)] were determined. Concordance between the indices obtained was calculated by direct and indirect measurement using the Kappa statistic.

RESULTS

A total of 313 students were enrolled; 172 (55%) were female and 141 (45%) male. The agreement between the direct and indirect facial index measurements was 0.189 (95% CI 0.117-0261), and the cranial index was 0.388 (95% CI 0.304-0.473), indicating poor concordance.

CONCLUSIONS

No agreement was observed between direct measurements conducted with an anthropometer and indirect measurements via visual evaluation. Therefore, the indirect visual classification method is not appropriate to calculate the cranial and facial indices.

Symmetry of external auditive meatus. A pilot study on human skulls

OBJECTIVES. To evaluate the perpendicularity of the line connecting external auditive meatus to the midsagital plane and the palatal suture as a midsagittal symmetry reference line. Setting and Sample Population - 62 randomly chosen human skulls from osteological collection (Vilnius University). MATERIAL AND METHODS. The skulls were photographed (Nikon 40 D, Nikkor lens 50 mm) from basal, frontobasal and frontal views. Photos were analysed with Adobe Photoshop CS5 (Adobe). The first line connected frontal points of external auditive meatus and the angle to the midsagittal plane was measured. The second line (the palatal suture) was compared to the median sagittal plane. Data was analysed with SPSS 17 (IBM). RESULTS. The mean value for the angles of the line between the external auditive meatus and the midsagittal plane in basal views was 90.12° (SD=1.48°) and in frontobasal 90.36° (SD=2.25°). No statistically significant differences were found between groups of age and sex. The inter-rater agreement for evaluation of the adequacy of palatal suture with the midsagital plane was high (Cohen's Kappa 0.702 (p<0.05)) as well as the coincidence of both lines in basal and frontobasal views (90.3% and 85.5% respectively). CONCLUSION. Considering the limits of this study the angle between external auditive meatus and midsagital skull plane has a characteristic fluctuating asymmetry. The congruence of palatal suture and midsagital plane is debatable.

Stereotaxis of mandibular nerve initial point of trigeminal ganglion in rats

OBJECTIVE

To acquire parameters for stereotaxis of the mandibular nerve initial point of the trigemenial ganglion (TG) and to test the accuracy of the acquired parameters for microinjection into the mandibular nerve initial point of TG in adult rats.

METHODS

Sprague-Dawley rats (260-270 g) were mounted onto a stereotaxic frame. The bregma was set as an anchor point and the three-dimensional parameters between the mandibular nerve initial point of the bilateral TGs and the bregma were measured in 25 rats. The accuracy of these parameters was tested using microinjection of Evans blue dye into the mandibular nerve initial point of the bilateral TGs in 30 rats and the injection sites were evaluated by dissection.

RESULTS

The three-dimensional parameters of the mandibular nerve initial point of the bilateral TGs were 3.5 ± 0.1 mm posterior and 3.6 ± 0.2 mm lateral to the bregma, and 12.0 ± 0.2 mm inferior to the skull surface. Accuracy for the microinjection of Evans blue dye into the mandibular nerve initial point of the bilateral TGs was 86.7% (52/60).

CONCLUSION

The acquired parameters served well for stereotaxis and microinjection of reagents into the mandibular nerve initial point of TG.

Reproducibility of facial soft tissue landmarks on facial images captured on a 3D camera

OBJECTIVE

Fast and non-invasive systems of the three-dimensional (3D) technology are a recent trend in orthodontics. The reproducibility of facial landmarks is important so that 3D facial measurements are accurate and may-be applied clinically. The aim of this study is to evaluate the reproducibility of facial soft tissue landmarks using a non-invasive stereo-photogrammetry 3D camera.

MATERIAL AND METHODS

Twenty-four soft tissue landmarks on 3D facial images captured using a VECTRA-3D dual module camera system for full face imaging (Canfield Scientific inc, Fairfield, NJ, USA) were viewed and analysed using Mirror software on 30 adult subjects (15 males and 15 females, in the age range of 20-25 years). The landmarks were identified, recorded and measured twice on each 3D facial image by one examiner after a 2-week interval. Intra-class correlations and paired t-test or Wilcoxon Rank test were performed for each landmark to assess intra-examiner reproducibility.

RESULTS

Intra-class correlation coefficients for all 24 landmarks ranged from 0.68 to 0.97, indicating moderate to high reliability and reproducibility of all facial soft tissue landmarks. Paired t-tests and Wilcoxon Rank test also revealed that there were no significant differences in all 24 facial soft tissue landmarks measurements (p = 0. 17 - 0.99).

CONCLUSION

The results indicated that the reproducibility of identification of landmarks by one operator on facial images captured using a VECTRA-3D camera was acceptable. This device may be useful in treatment planning and may provide accurate information in making clinical decisions. However, it is suggested that further studies on inter-examiner reproducibility should be undertaken.

Accuracy and benefits of 3D bone surface modelling: a comparison of two methods of surface data acquisition reconstructed by laser scanning and computed tomography outputs

The aim of this study is to compare two different methods of frontal bone surface model acquisition. Three dimensional models acquired by laser scanning were compared with models of the same bones acquired by virtual replicas reconstructed from a sequence of computed tomography (CT) images. The influence of volumetric CT data processing (namely thresholding), which immediately preceded the generation of the three-dimensional surface model, was also considered and explored in detail in one sample. Despite identifying certain areas where both models showed deviations across all samples, their conformity can be generally classified as satisfactory, and the differences can be regarded as minimal. The average deviation of registered surface models was 0.27 mm for 90% of the data, and its value was therefore very close to the resolution of the laser scanner used.

Cortical thickness parameters for endoscopic browlift fixation

BACKGROUND

Techniques for endoscopic browlift include bony fixation over the lateral frontal region and soft tissue fixation over the temporal region. Although bony fixation over the lateral frontal region is advocated universally, limited information exists about bicortical thickness in this area.

OBJECTIVES

The authors provide bicortical thickness measurements between the frontal midline and the most inferior temporal region to assist surgeons in identifying appropriate fixation planes.

METHODS

Bicortical thickness was measured in the hemicraniums of 13 female cadavers, along the coronal planes that travel through the anterior border of the mandibular condyles and at the junction of the posterior mandibular condyles and the external auditory meatuses. Measurements began at the midline and coursed laterally at 1-cm intervals.

RESULTS

Average cranial thickness along the frontal region ranged from 8.9 ± 2.4 mm to 6.4 ± 2.8 mm over the anterior coronal line and 8.8 ± 2.2 mm to 5.6 ± 1.8 mm over the posterior line. Average thickness along the temporal region ranged from 5.6 ± 2.8 mm to 2.8 mm ± 1.4 mm over the anterior coronal line and 5.1 ± 1.8 mm to 3.4 ± 1.4 mm over the posterior line. Minimum thickness was 3.7 mm and 1.3 mm over the frontal and temporal regions, respectively. There was no significant difference between left and right hemicranial thickness.

CONCLUSIONS

To avoid violation of the inner cortex during surgery, endoscopic browlift procedures should include measurement of cortical thickness at various fixation points. Bony fixation over the temporal region should be avoided. Minimal bicortical thickness was observed in the lateral frontal region.

The occurrence of phi in dento-facial beauty of fine art from antiquity through the Renaissance

External beauty is a complex construct that influences lives and may be impacted by dentists. Beauty is not easily quantified, but one cited anthropometric of beauty is the ratio phi, the number 1.618033(...). This study examined phi as a measure of female frontal facial beauty in classic Western art, using pre- Renaissance (N = 30), and Renaissance (N = 30) artwork. Four horizontal and five vertical ratios were determined in the works of art, which were then compared with the phi ratio. All horizontal ratios for both pre-Renaissance and Renaissance artwork were similar to each other, but did not contain the phi ratio (P < 0.001). Nevertheless, all vertical ratios for pre-Renaissance and Renaissance art-work did contain the phi ratio within their confidence intervals with the exception of the vertical ratio, "intereye point to soft tissue menton/ intereye point to stomion", that was found to be less than phi in the Renaissance group. The study provides evidence of the presence of the phi ratio in vertical aspect of females in artwork from pre-Renaissance through the Renaissance demonstrating consistent temporal preferences. Therefore, the phi ratio seems to be an important consideration in altering vertical facial dimensions in full mouth rehabilitation and reconstructive orthognathic surgery involving females.

[Applied anatomy of the fontanelles]

OBJECTIVE

To make a description of the anatomy of fontanelles and to update what is currently known about their applications.

METHOD

7 cadaveric heads, 2 dry skulls and 2 frontal bones of foetus were used, and 48 anterior fontanelles from paediatric patients with or without associated pathology were examined. Surgical cases and neurosonography were also used. All the structures were measured and subsequently analysed.

RESULTS

The size, structure and limits of the fontanelles were evidenced in the cadaveric head and skulls, as well as the evaluation of paediatric patients and the size of their fontanelles in different pathologies.

CONCLUSION

Owing to their anatomical characteristics, fontanelles are a true window to the inside of the skull, which determines their multiple clinical and surgical applications.

Anatomical consideration of the anterior and lateral cutaneous nerves in the scalp

To better understand the anatomic location of scalp nerves involved in various neurosurgical procedures, including awake surgery and neuropathic pain control, a total of 30 anterolateral scalp cutaneous nerves were examined in Korean adult cadavers. The dissection was performed from the distal to the proximal aspects of the nerve. Considering the external bony landmarks, each reference point was defined for all measurements. The supraorbital nerve arose from the supraorbital notch or supraorbital foramen 29 mm lateral to the midline (range, 25-33 mm) and 5 mm below the supraorbital upper margin (range, 4-6 mm). The supratrochlear nerve exited from the orbital rim 16 mm lateral to the midline (range, 12-21 mm) and 7 mm below the supraorbital upper margin (range, 6-9 mm). The zygomaticotemporal nerve pierced the deep temporalis fascia 10 mm posterior to the frontozygomatic suture (range, 7-13 mm) and 22 mm above the upper margin of the zygomatic arch (range, 15-27 mm). In addition, three types of zygomaticotemporal nerve branches were found. Considering the superficial temporal artery, the auriculotemporal nerve was mostly located superficial or posterior to the artery (80%). There were no significant differences between the right and left sides or based on gender (P>0.05). These data can be applied to many neurosurgical diagnostic or therapeutic procedures related to anterolateral scalp cutaneous nerve.

Temporal miniplates in the frontozygomatic area--an anatomical study

PURPOSE

The advantages of rigid fixation over wire osteosynthesis are well established for the management of facial trauma. Miniplates in the frontozygomatic area are traditionally applied to the lateral face of the orbital rim, but with some undesirable effects, such as palpability, visibility, and risk of penetration into the anterior cranial fossa. The aim of this study was to perform an anatomical study to validate the use of miniplates on the temporal face of the frontozygomatic region.

METHODS

Osseous thickness measurements were performed in 30 skulls, on four points above and four below the suture, at 3-mm intervals, perpendicular to the bone surface.

RESULTS

There is enough bone thickness to apply the screws, ranging between 4 and 6.5 mm. The first hole over the frontozygomatic suture should receive the smallest screws and the other areas can receive screws up to 6 mm. All drillings are made from the temporal fossa to the orbit, and its contents should therefore be protected during the perforations. At the measured points there is no risk of anterior cranial fossa penetration.

CONCLUSION

This study suggests that it is possible to use miniplates at the temporal aspect of the frontozygomatic suture.

Validity of the frontolateral approach as a minimally invasive corridor for olfactory groove meningiomas

BACKGROUND

Several approaches are described for olfactory groove meningiomas (OGMs) varying from a very wide bifrontal craniotomy to minimally invasive endoscopic techniques. The goal of this study was to evaluate the results of the frontolateral approach for olfactory groove meningioma. Pitfalls related to this corridor will be described. The impact of tumor size and encasement of the anterior cerebral artery complex on the degree of tumor removal will be described on the basis of experience with 18 cases.

METHODS

Eighteen patients with OGM underwent microsurgical removal using the frontolateral approach. A retrospective study was conducted by analyzing clinical data, neuroimaging studies, operative findings, clinical outcome, and degree of tumor removal.

FINDINGS

The patients were classified into group A with tumor size less than 4 cm in diameter (7 out of 18 cases, 38.9%) and group B with tumor size more than 4 cm in diameter (11 out of 18 cases, 61.1%). CSF rhinorrhea was observed in three patients (16.7%). Postoperative left frontal intracerebral hematoma occurred in one patient (5.6%) belonging to group A. In another patient (5.6%) belonging to group B, marked right frontal lobe swelling was evident after dural opening, which necessitated partial right frontal pole resection. Total tumor removal (Simpson grade 1 and 2) was achieved in 14 out of 18 patients (77.8%), while subtotal removal (Simpson grade 3 and 4) was achieved in 4 patients (22.2%). In the 14 patients in whom total removal was achieved, 7 belonged to group A (all 7 patients of group A with 100% removal), while the remaining 7 patients belonged to group B (7 out of 11 patients, 63.6% removal; one of them had anterior cerebral artery complex encasement). The four patients in whom subtotal removal was achieved belonged to group B; three of them showed anterior cerebral artery complex encasement, and one elderly patient had non-extensive paranasal sinus involvement. One patient (5.6%) in group B died from cerebral infarction after subtotal tumor removal with anterior cerebral artery injury during its dissection from the tumor capsule.

CONCLUSION

The frontolateral approach has the advantages of both the pterional and conventional bifrontal approaches. The frontolateral approach allows quick and minimally invasive access to OGMs less than 4 cm in diameter, and also to tumors more than 4 cm in diameter without encasement of the anterior cerebral artery complex. Tumor size more than 4 cm in diameter and encasement of the anterior cerebral artery complex are limiting factors for the frontolateral approach if radical tumor removal is considered.

Is eyebrow approach suitable for ruptured anterior circulation aneurysms on early stage: a prospective study at a single institute

OBJECTIVE

A prospective study was underway to evaluate the outcome of eyebrow keyhole approach for ruptured anterior circulation aneurysms on early stage.

METHODS

In the past 4 years, 88 patients with ruptured anterior circulation aneurysms, were operated on early stage by an experienced neurosurgical team through eyebrow craniotomy. The clinical data were analyzed.

RESULTS

Patients with Hunt and Hess Grade I-II (85.2%) or III (14.8%) were selected for eyebrow approach on early stage. All aneurysms were small (20.5%) or middle (79.5%) in size. All but seven (92.0%) aneurysms were clipped successfully. The opening of frontal sinus occurred in 11(12.5%) cases through eyebrow approach. Of all, 78 (88.6%) patients achieved favorable outcomes.

CONCLUSIONS

Eyebrow keyhole approach for ruptured anterior circulation aneurysms on early stage might be in particular selected according to the Hunt and Hess Scale, the projection of aneurysm, the length of M1 segment, the location of cerebral hematoma, the size and complexity of aneurysm, as well as the preference and experience of the neurosurgical team.

Angular photogrammetric analysis of the soft tissue facial profile of Turkish adults

One of the most important components of orthodontic diagnosis and treatment planning is the evaluation of the patient's soft tissue profile. The aim of this study was to develop angular photogrammetric standards for Class I Anatolian Turkish males and females. A random sample of 100 Turkish individuals (46 males and 54 females; ages 19-25 years) was obtained. The photographic set-up consisted of a tripod that held a 35 mm camera and a primary flash. The camera was used in its manual position and photographic records were taken of the subjects in natural head posture. The photographic records, 35 mm slide format, were digitized and analyzed using the Quick Ceph Image software program for Windows. Twelve measurements were digitally analyzed on each photograph. For statistical evaluation a Student's t-test was performed and the reliability of the method was analyzed. The results were compared with reported norms of facial aesthetics. The nasofrontal (G-N-Prn), nasal (Cm-Sn/N-Prn), vertical nasal (N-Prn/TV), and nasal dorsum (N-Mn-Prn) angles showed statistically insignificant gender differences (P>0.05). The nasolabial angle (Cm-Sn-Ls) demonstrated large variability. Gender differences were present in the mentolabial (Li-Sm-Pg) and cervicomental (G-Pg/C-Me) angles. The mentolabial angle showed a high method error and large variability. Facial (G-Sn-Pg) and total facial (G-Prn-Pg) convexity angles were similar, while Cm-Sn-Ls angle range was larger compared with other angles. The mean values obtained from this sample can be used for comparison with records of subjects with the same characteristics and following the same photogrammetric technique. Angular photogrammetric profile analysis can provide the orthodontist with a way of determining problems associated with various soft tissue segments of the face.

Giant olfactory groove meningioma: ophthalmological and cognitive outcome after bifrontal microsurgical approach

OBJECT

Olfactory groove meningiomas arise in the midline along the dura of the cribriform plate and may reach a large size before producing symptoms. We conducted a retrospective study of patients with these lesions focused on pre- and post-operative investigations for ophthalmological, personality and cognitive disturbances.

METHODS

The authors reviewed 36 patients with giant olfactory groove meningiomas surgically treated via a bifrontal approach. Ophthalmological evaluation included visual acuity, fundoscopy and visual fields while psychological evaluation included a Mini-Mental State Examination. Data was collected before, 1 and 12 months after surgery. Formal pre- and post-operative ophthalmological examinations discovered visual deficits in 55.5% of the patients. Within the first month after surgery, improvement of visual acuity and of visual field deficits was observed. In post-operative neuropsychological testing, higher mental functions showed improvement. The most frequent post-operative complication was persistent rhinorrhoea in two patients.

CONCLUSIONS

Results at longest follow up indicate that cognitive changes and visual deficits will improve in patients with giant olfactory groove meningiomas after a bifrontal approach, without additional neurological deficits.

Persistent metopic suture can mimic the skull fractures in the emergency setting?

Metopism is partially or totally persisting suture extending from the nasion to the anterior angle of the bregma. The time of physiological closure of the metopic suture varies from birth to 8 years of age. Widely accepted closuring time is approximated at 2 years of age. Although formerly reported skull studies mentioned the persistent metopic suture, it is extremely rare in clinical practice. We presented a trauma case of 43 years of age who was demonstrated radiologically to have a persisting suture. Persistent metopic suture may be misdiagnosed as a vertical traumatic skull fracture extending in the mid-line in head trauma patients. Therefore the surgeon should be aware of this anatomical condition in the primary and secondary surveillance of the traumatized patient and during surgical intervention including especially frontal craniotomy. Reconstructed tomography scan demonstrating sutural closuring status may provide additional informative value in the diagnostic sequence superior to plain X-ray in the emergency setting.

A fourth hominin skull from Dmanisi, Georgia

Newly discovered Homo remains, stone artifacts, and animal fossils from Dmanisi, Republic of Georgia, provide a basis for better understanding patterns of hominin evolution and behavior in Eurasia ca. 1.77 million years ago. Here we describe a fourth skull that is nearly complete, lacking all but one of its teeth at the time of death. Both the maxillae and the mandible exhibit extensive bone loss due to resorption. This individual is similar to others from the site but supplies information about variation in brain size and craniofacial anatomy within the Dmanisi paleodeme. Although this assemblage presents numerous primitive characters, the Dmanisi skulls are best accommodated within the species H. erectus. On anatomical grounds, it is argued that the relatively small-brained and lightly built Dmanisi hominins may be ancestral to African and Far Eastern branches of H. erectus showing more derived morphology.

Inheritance of sutural pattern at the pterion in rhesus monkey skulls

Five of the bones that characteristically comprise the cranial vault articulate on the lateral aspect of the skull at or near the cephalometric landmark referred to as the pterion. The pattern of articulation in the sutures associated with these bones varies among and within primate species and has been used as a criterion for classification in taxonomic studies, as well as in archeological and forensic studies. Within species, the sutural patterns found within the region of the pterion have remarkable consistency, which lead to the hypothesis that these patterns have a genetic basis. Sutural pattern variations were investigated at the pterion in 422 skulls from 66 rhesus monkey families with known genealogies from the long-standing colony on Cayo Santiago. Four specific types of articulation patterns were recorded. The results demonstrated that the most common suture pattern at the pterion of Cayo Santiago rhesus monkeys (86%; similar to that seen in some other anthropoid species but not humans and some apes) was characterized by an articulation between the temporal bone and parietal bone. Articulation between the sphenoid and parietal bones (type SP) accounted for 14% of the specimens and was concentrated in a dozen families. Mothers with the SP phenotype had a high incidence of offspring with SP phenotypes. Most non-SP mothers having SP offspring had siblings or family members from previous generations with the SP type. This is the first study to examine variation in sutural patterns at the pterion in pedigrees. Variation of sutural patterns shows familial aggregation, suggesting that this variation is heritable. Future work will be focused on defining the inheritance patterns of variation at the pterion, with the ultimate objective of identifying the specific genes involved and their mechanism of action.

The endoscopic supraorbital approach to tumors of the middle cranial base

BACKGROUND

Access to tumors of the middle cranial base has traditionally required wide surgical exposures via open craniotomies. These open techniques often require the use of potentially disfiguring skin incisions and are often associated with a significant degree of brain retraction and potential morbidity. We report our experience with the use of a minimally invasive supraorbital endoscopic approach through the eyebrow for excision of middle cranial base tumors in 2 cases.

METHODS

We describe 2 patients with large-sized middle cranial fossa tumors (a medial sphenoid wing meningioma measuring 6 x 4 cm and a recurrent right cavernous sinus meningioma measuring 4 x 3.5 cm) that were entirely removed via a fully endoscopic supraorbital approach using a 1.5-cm keyhole craniotomy.

CONCLUSION

These cases demonstrate how the application of endoscopic techniques to surgery of the middle cranial base can eliminate the need for traditional open techniques without compromising surgical success.

Surgical exposure of lateral orbital lesions using a coronal scalp flap and lateral orbitozygomatic approach: clinical experience

BACKGROUND

The lateral extraconal compartment is a typical localization of intra-orbital tumours. With the exception of anterior lesions, which can be reached by a transconjuntival route, most of these tumours are currently approached through the classic lateral orbitotomy originally described by Kronlein. We present here our experience in the management of lateral orbital lesions, using a coronal skin flap, followed by subfascial dissection of the temporalis muscle. The procedure was intended to overcome the potential drawbacks associated with the classic transtemporal approach.

METHODS

The approach was used in eleven patients harbouring bone lesions of the lateral orbital wall or intra-orbital lesion of the lateral extra-ocular compartment. The postoperative results were assessed using a simple cosmetic outcome scale, which evalutated the temporalis muscle trophism and the function of the frontotemporal branch of the facial nerve.

RESULTS

All lesions were satisfactorily exposed. The subfascial dissection of the temporalis muscle is a key manoeuvre which, at the same time, abolishes the risk of injury to the frontotemporal branch of the facial nerve and provides a wide exposure of the lateral orbital wall. The cosmetic outcome was excellent in 9 patients and good in 2 patients.

CONCLUSIONS

The reported technique is a convenient surgical option to approach lateral intra-orbital lesions, with a minimal cosmetic impact.

Eyebrow Surgery: The Supraciliary Craniotomy: Technical Note

OBJECTIVE:

Many approaches have been recommended for the surgical treatment of anterior and middle cranial fossa lesions. The frontobasal approach and its many modifications have been proposed and developed for such situated lesions. An alternative approach is the frontolateral craniotomy through a supraciliary skin incision.

METHODS:

This minimally invasive technique, a 2.5 × 3.0 cm craniotomy, just above the eyebrow through a supraciliary incision, is a simple but elegant modification of the traditional approach to the anterior cranial fossa.

RESULTS:

A step-by-step description of the approach is offered in this report to facilitate a clear understanding of the lesions treatable with this minimally invasive technique.

CONCLUSION:

The supraciliary frontolateral keyhole craniotomy is a minimally invasive cosmetic approach that provides excellent exposure to a variety of intracranial lesions. This approach cannot be used for all intracranial pathologies, but is recommended for many anterior and middle cranial fossa lesions.

Patterning of geographic variation in Middle Pleistocene Homo frontal bone morphology

A quantitative assessment of the frontal bone morphology of a sample of Middle Pleistocene hominins was undertaken in order to address questions regarding their population structure and evolutionary history. Outline tracings of the frontal bones of forty-seven fossil crania were obtained, and size-standardized measurements were then computed using an Elliptical Fourier analysis of these tracings. Principal component scores of the Fourier harmonic amplitudes were derived and served as a quantitative representation of the morphology of the frontal bone. Morphological, geographical, and temporal distance matrices were then constructed between each pair of fossils. A partial Mantel matrix correlation test was performed between morphological and geographical distance matrices, controlling for temporal distance, in order to determine if the pattern of geographical differentiation in features of the frontal bone of mid-Pleistocene Homo followed that of an isolation-by-distance model of population structure. The results of the partial Mantel tests indicate that the overall patterning of differentiation in the features of the frontal bone cannot best be explained by a population structure shaped by isolation-by-distance. Additionally, various aspects of the frontal bone quantified here follow different patterns of geographical differentiation, suggesting that a mosaic pattern of evolution holds true for characters within one cranial region and not just for those between regions.

The role of the superciliary approach in the surgical management of intracranial neoplasms

OBJECTIVE

The authors present and evaluate the experiences with 76 frontolateral keyhole craniotomies performed for supratentorial intracranial tumors via superciliary skin incisions.

METHOD

The exploration is a modification of the generally used pterional approach. Out of a series of 302 cases operated on with frontolateral keyhole craniotomies via superciliary skin incisions, 76 had various tumors at the frontal base, intra-, supra-, parasellar and intraorbital regions. The operations were carried out through a approximately 2.5 x 3 cm frontolateral miniaturized craniotomy following a skin incision at the upper edge of the eyebrow.

CONCLUSION

Despite the small size of craniotomy the superciliary approach is a suitable technique for resection of skull base tumors in the anterior fossa, orbit, sellar, parasellar and suprasellar regions. The exploration allows enough room for intracranial surgical manipulation with maximal protection of normal brain, vessel and nerve structures. The presented patients did not have any craniotomy-related complication.

Taxonomic status of purported primate frontal bones from the Eocene Pondaung Formation of Myanmar

Two isolated cranial fragments from the late middle Eocene Pondaung Formation of central Myanmar have previously been interpreted as frontal bones of the amphipithecid primate Amphipithecus mogaungensis. Aside from a few maxillary fragments, these specimens provide the only potential source of information currently available regarding the cranial anatomy of Amphipithecidae. Were this taxonomic attribution correct, these specimens would indicate that amphipithecids retained numerous primitive skull features, including the absence of a postorbital septum, the retention of a voluminous olfactory chamber, and strong separation between the forebrain and the orbital fossa. However, several anatomical details observable on these specimens are incompatible with their attribution to any primate and strongly suggest that they cannot be ascribed to Mammalia. Particularly problematic in this regard are the extreme thickness of the dermal bone, the odd structure of the alleged "frontal trigon," and the mediolateral orientation and uniquely robust construction of the descending process of the frontal bone (which partially segregates the orbital and temporal fossae). Because these isolated elements can no longer be attributed to Amphipithecus, the anatomical, phylogenetic, and behavioral inferences regarding amphipithecid paleobiology that have been drawn from these specimens can no longer be sustained.

Description, new reconstruction, comparative anatomy, and classification of the Sterkfontein Stw 53 cranium, with discussions about the taxonomy of other southern African early Homo remains

Specimen Stw 53 was recovered in 1976 from Member 5 of the Sterkfontein Formation. Since its incomplete initial description and comparison, the partial cranium has figured prominently in discussions about the systematics of early Homo. Despite publication of a preliminary reconstruction in 1985, Stw 53 has yet to be compared comprehensively to other Plio-Pleistocene fossils or assessed systematically. In this paper, we report on a new reconstruction of this specimen and provide a detailed description and comparison of its morphology. Our reconstruction differs in important respects from the earlier one, especially in terms of neurocranial length, breadth, and height. However, given that Stw 53 exhibits extensive damage, these dimensions are most likely prone to much error in reconstruction. In areas of well-preserved bone, Stw 53 shares many cranial features with Homo habilis, and we propose retaining it within this species. We also consider the affinities of dental remains from Sterkfontein Member 5, along with those from Swartkrans and Drimolen previously assigned to Homo. We find evidence for sympatry of H. habilis and Australopithecus robustus and possibly Plio-Pleistocene Homo sapiens sensu lato in Sterkfontein Member 5. At Swartkrans and Drimolen, we find evidence of H. habilis. We also compare the morphologies of Stw 53 and SK 847 and find compelling evidence to assign the latter specimen to H. habilis, as has been proposed.

Deformation of the human brain induced by mild acceleration

Rapid deformation of brain matter caused by skull acceleration is most likely the cause of concussion, as well as more severe traumatic brain injury (TBI). The inability to measure deformation directly has led to disagreement and confusion about the biomechanics of concussion and TBI. In the present study, brain deformation in human volunteers was measured directly during mild, but rapid, deceleration of the head (20-30 m/sec2 peak, approximately 40 msec duration), using an imaging technique originally developed to measure cardiac deformation. Magnetic resonance image sequences with imposed "tag" lines were obtained at high frame rates by repeating the deceleration and acquiring a subset of image data each repetition. Displacements of points on tag lines were used to estimate the Lagrangian strain tensor field. Qualitative (visual) and quantitative (strain) results illustrate clearly the deformation of brain matter due to occipital deceleration. Strains of 0.02-0.05 were typical during these events (0.05 strain corresponds roughly to a 5% change in the dimension of a local tissue element). Notably, compression in frontal regions and stretching in posterior regions were observed. The motion of the brain appears constrained by structures at the frontal base of the skull; it must pull away from such constraints before it can compress against the occipital bone. This mechanism is consistent with observations of contrecoup injury in occipital impact.

Cranial anatomy of the spade-headed amphisbaenianDiplometopon zarudnyi (Squamata, amphisbaenia) based on high-resolution X-ray computed tomography

The skull of the trogonophid amphisbaenian Diplometopon zarudnyi is described from high-resolution X-ray computed tomographic (HRXCT) imagery of a whole museum specimen preserved in ETOH. The skull was digitally resliced and disarticulated into individual elements, producing novel visualizations that allow detailed morphological analysis of its three-dimensionally complex structure. The prefrontal and jugal are absent in Diplometopon. The septomaxilla is present but hidden entirely from superficial view. In contrast to previous studies, we recognize a splenial fused to the compound bone of the mandible and a squamosal fused to the otic-occipital complex. Comparison of Diplometopon to the two other amphisbaenians previously described in comparable detail, Rhineura hatcherii and Amphisbaena alba, reveals a mosaic of cranial similarities and differences. Both Diplometopon and Rhineura exhibit a craniofacial angulation and expanded rostral blade related to use of the head as a digging tool, but the detailed architecture of these features is quite different. Additionally, whereas the snout of Rhineura exhibits a high degree of sculpturing and sensory innervation, this is not the case in Diplometopon. Unlike in Rhineura and Amphisbaena, the cranial elements of Diplometopon do not exhibit an extensive degree of overlap or complex interlocking sutures; instead, most of the cranial elements lie in loose apposition to each other. The degree to which this mosaic of features reflects functional demands, shared ancestry, and/or convergence is unclear in the absence of a stable hypothesis of amphisbaenian phylogeny.

Supraorbital eyebrow minicraniotomy for anterior circulation aneurysms

BACKGROUND

We report our experience with the minimally invasive supraorbital approach to aneurysms of the ipsilateral anterior cerebral circulation.

METHODS

A prospective review of all patients who underwent operations to clip aneurysms in Newcastle between 1993 and 2002.

RESULTS

Fifty-six aneurysms were clipped via minicraniotomy in 47 patients. Six patients presented with acute subarachnoid hemorrhage (SAH), 40 patients were admitted for elective clipping, and 1 patient presented with an SAH, had the responsible aneurysm clipped and was readmitted later for elective clipping of a further aneurysm. Bilateral supraorbital craniotomies were performed in 3 patients. In 6 patients, multiple aneurysms were clipped via a single craniotomy. All aneurysms were well visualized with the microscope. Endoscopic assistance was not found necessary. All were successfully clipped. Two aneurysms ruptured while being clipped. There was no direct mortality from surgery. One patient died later from a separate posterior circulation aneurysm. One patient had a significant long-term deficit but remained independent, and 1 had 3 seizures over the 12 months after surgery. This represents a 4% morbidity at 1 year.

CONCLUSION

Selected anterior cerebral circulation aneurysms can be clipped with low morbidity, using an ipsilateral minicraniotomy preserving the orbital rim, and without using an endoscope. The types of aneurysm selection criteria and operative equipment used are described.

A note on the morphology of the metopic suture in the human skull

The metopic suture of 24 adult skulls investigated showed recognisable varied morphological patterns. The metopic suture resembled wavy lines and was sometimes highly convoluted, especially in the superior part of the frontal bone. The mean suture length was computed as 123.1 mm (SD = 5.307) and the mean fractal dimension was 1.17 (SD = 0.076). Visual inspection of the morphological character of the metopic sutures revealed complex variation in their course between the nasion and the bregma. Comparison of the fractal dimensions indicated a two-fold increase in complexity between the anterior half of the suture terminating in the nasion (FD = 1.10) and the second half of the suture beginning in the bregma (FD = 1.21). The Mann-Whitney test confirmed the statistical significance of the differences in the fractal dimensions calculated. The variety and complexity of the interdigitations in the anterior and posterior part of the suture point to possible alterations to local strains, which occur during the growth of the braincase.

Msx2 and Twist cooperatively control the development of the neural crest-derived skeletogenic mesenchyme of the murine skull vault

The flat bones of the vertebrate skull vault develop from two migratory mesenchymal cell populations, the cranial neural crest and paraxial mesoderm. At the onset of skull vault development, these mesenchymal cells emigrate from their sites of origin to positions between the ectoderm and the developing cerebral hemispheres. There they combine, proliferate and differentiate along an osteogenic pathway. Anomalies in skull vault development are relatively common in humans. One such anomaly is familial calvarial foramina, persistent unossified areas within the skull vault. Mutations in MSX2 and TWIST are known to cause calvarial foramina in humans. Little is known of the cellular and developmental processes underlying this defect. Neither is it known whether MSX2 and TWIST function in the same or distinct pathways. We trace the origin of the calvarial foramen defect in Msx2 mutant mice to a group of skeletogenic mesenchyme cells that compose the frontal bone rudiment. We show that this cell population is reduced not because of apoptosis or deficient migration of neural crest-derived precursor cells, but because of defects in its differentiation and proliferation. We demonstrate, in addition, that heterozygous loss of Twist function causes a foramen in the skull vault similar to that caused by loss of Msx2 function. Both the quantity and proliferation of the frontal bone skeletogenic mesenchyme are reduced in Msx2-Twist double mutants compared with individual mutants. Thus Msx2 and Twist cooperate in the control of the differentiation and proliferation of skeletogenic mesenchyme. Molecular epistasis analysis suggests that Msx2 and Twist do not act in tandem to control osteoblast differentiation, but function at the same epistatic level.

[Morphometric characteristics and correlation interdependence of the lacrimal sac fossa and nasolacrimal canal in cerebral and facial parts of the skull of various shape]

Morphometric characteristics of lacrimal sac fossa (LSF) and nasolacrimal canal (NLC) were studied in 105 macerated skulls of humans of mature age. Extreme shape variants were detected for LSF and NLC inferior foramen. The peculiarities of topographic-anatomical relations of NLC with the neighboring structures of nasal cavity were established. Morphometric characteristics of LSF and NLC were found to be largely determined by the shapes of facial part of the skull, nasal cavity and orbit, and to a lesser extent by the shape of cerebral part of the skull. Some variants of LSF and NLC topographic-anatomical localization were found to exist that could predispose to spreading of an inflammatory process from the adjoining areas. Correlation analysis of morphogenetic relations of LSF and NLC has demonstrated significant dependence of only some dimensions in each of the skull shape variants.

[Coronal approach. Surgical technique]

Many indications in maxillo-facial surgery require a coronal approach. We recall the main anatomic features and describe the surgical technique.

The pterion in Turkish male skulls

This study was conducted to determine the location and type of pterion in Turkish males. The importance of the pterion is its relation to the middle meningeal artery, Broca's motor speech area on the left side, and surgical interventions relating to pathologies of the sphenoid ridge and optic canal. Specific measurements were taken on both sides of 26 Turkish human male skulls, none of which showed any obvious pathology or trauma. The sphenoparietal type of pterion was the most common (96% right side, 79% left side), followed by the frontotemporal (4% right side, 17% left side), and finally the epipteric type (4% left side only). The distances on the right and left sides respectively from the center of the pterion to the frontozygomatic suture were 3.30+/-0.40 cm and 3.44+/-0.39 cm, to the zygomatic arch 4.05+/-0.39 cm and 3.85+/-0.25 cm, to the optic canal 4.39+/-0.40 cm and 4.36+/-0.40 cm, and to the sphenoid ridge 1.40+/-0.33 cm and 1.48+/-0.32 cm. The thickness of the skull at the center of the pterion was 0.41+/-0.14 cm and 0.39+/-0.12 cm on the right and left sides respectively. These findings should be of use in surgical approaches and interventions via the pterion.

Prenatal Organization and Morphogenesis of the Sphenofrontal Suture in Humans

OBJECTIVE

The aim of this study was to describe the prenatal structure and morphogenesis of the sphenofrontal suture.

METHODS

Eleven human specimens, two embryos and nine fetuses, were prepared for light microscopy study of the sphenofrontal suture. Ten-micrometer sections were made with the microtome in the sagittal plane from the midline to the sphenoidal fontanelle.

RESULTS

At the end of the fetal period, the sphenofrontal suture had a five-layer structure like the cranial sutures, and was formed by two different morphogenetic unities. The orbitosphenofrontal suture was formed between the membranous ossification of the orbital part of the frontal bone and the endochondral ossification of the lesser wing of the sphenoid bone, i.e. the ala orbitalis. In the early stage, a transient sphenoethmoidal cartilage was inserted between these two ossifications. The second unit, the lateral sphenofrontal suture, was formed between the frontal bone and the greater wing of the sphenoid, and the ossification was membranous in this portion. It is formed like the cranial suture, directly from the mesenchyme.

CONCLUSION

The sphenofrontal suture is a typical fibrous suture arising from two morphogenetic unities.

Angular photogrammetric analysis of the soft tissue facial profile

All medical specialties interested in improving facial appearance need to measure the face to quantify the desired facial changes. The purpose of this investigation was to obtain objective average measurements of the soft tissue facial profile to use them as a guide for aesthetic treatment goals. The analysis of the soft tissue facial profile from photographic records provides information on the morphology of the profile and its relationship with the underlying dentoskeletal tissues. In this investigation the soft tissue facial profile of a young adult European Caucasian population (212 individual, 50 males and 162 females, 18-20 years of age) was studied by means of standardized photographic records taken in the natural head position (NHP). Angular measurements were analysed digitally. Sexual dimorphism was found for several angles: nasofrontal (G-N-Prn: P < 0.01), vertical nasal (Cm-Sn/N-Prn: P < 0.01), nasal (N-Prn/TV: P < 0.01), nasal dorsum (N-Mn-Prn: P < 0.05), and mandibular contour (C-Me/G-Pg: P < 0.01). Wide individual variations in nasolabial and mentolabial angles were also observed.

Electronic removal of encrustations inside the Steinheim cranium reveals paranasal sinus features and deformations, and provides a revised endocranial volume estimate

Features in the endocranium, as revealed by computed tomography (CT) scans of largely complete mid-Pleistocene crania, have helped elucidate unexpected affinities in the genus Homo. Because of its extensive encrustations and deformations, it has been difficult to repeat such analyses with the Steinheim cranium. Here, we present several advances in the analysis of this Homo heidelbergensis cranium by applying filter algorithms and image editing techniques to its CT scan. First, we show how the encrustations have been removed electronically, revealing interesting peculiarities, particularly the many directions of the deformations. Second, we point out similarities and differences between the frontal and sphenoidal sinuses of the Steinheim, Petralona, and Broken Hill (Kabwe) crania. Third, we assess the extent of the endocranial deformations and, fourth, their implications for our estimation of the braincase volume.

Longitudinal cephalometric standards for the neurocranium in Norwegians from 6 to 21 years of age

The purpose of this study was to establish and describe normative cephalometric standards of the neurocranium (theca cranii and cranial base) for Norwegian males and females from 6 to 21 years of age using lateral cephalograms. The subjects included 35 males and 37 females from the Oslo University Growth Archive with lateral cephalograms taken every third year from 6 to 21 years of age. The total number of lateral cephalograms was 194 from males and 200 from females. All subjects were Caucasian, all had normal occlusion and no apparent facial disharmony, and none had undergone orthodontic therapy. Nineteen measurements and three indices of the neurocranium were analysed longitudinally. Comparisons between the various parameters in the neurocranium of males and females in each age group were performed using the Student's t-test. The size of the neurocranium of females was smaller than that of males throughout the observation period and the differences increased with age, particularly the diameter of the neurocranium (n-l), length of the neurocranium (n-opc), anterior cranial base length (n-s), and posterior cranial base length (s-ba). The cephalometric standards of the neurocranium established in this study can be used as a reference material in investigations of individuals with various craniofacial aberrations and syndromes.

Morphological affinities of the Sal'a 1 frontal bone

The human frontal bone from Sal'a, Slovak Republic, has previously entered into discussions of the morphological patterns of Central European Neandertals and the origins of early modern humans in that region. A morphological reassessment of its supraorbital region and a morphometric analysis of its overall proportions indicate that it falls well within expected ranges of variation of Late Pleistocene Neandertals and is separate from European earlier Upper Paleolithic early modern human crania. It is similar to the Qafzeh-Skhul sample in some metrical and supraorbital robusticity measures, but it contrasts with them in mid-sagittal curvature and supraorbital torus morphology. In the context of its probable oxygen isotope stage 5 age based on inferred biostratigraphic associations, it should not be employed directly for arguments relating to the emergence of modern humans in Central Europe.

Biomechanical properties of high-density polyethylene for pterional prosthesis

The pterional approach is the most popular surgical technique in aneurysm and skull base tumor removal. Reconstruction of the temporal contour deformity due to craniotomy requires graft implantation. Porous high-density polyethylene (PHDPE) as a craniofacial and pterional implant material recently became available. However, material properties of the pterional implant are not yet known. In order to measure the biomechanical properties of PHDPE, we implemented the tensile test, the three-point bending test and the water displacement method for density measurement. Elastic modulus varies from 227 to 307MPa. Density range is 0.68 and 0.7 depending on the size of pores. The data can be used to study the character of the porous high-density polyethylene implant, how it resists stress or fatigue in combination with conventional plating systems.

A new skull of early Homo from Dmanisi, Georgia

Another hominid skull has been recovered at Dmanisi (Republic of Georgia) from the same strata in which hominid remains have been reported previously. The Dmanisi site dated to approximately 1.75 million years ago has now produced craniofacial portions of several hominid individuals, along with many well-preserved animal fossils and quantities of stone artifacts. Although there are certain anatomical differences among the Dmanisi specimens, the hominids do not clearly represent more than one taxon. We assign the new skull provisionally to Homo erectus (=ergaster). The Dmanisi specimens are the most primitive and small-brained fossils to be grouped with this species or any taxon linked unequivocally with genus Homo and also the ones most similar to the presumed habilis-like stem. We suggest that the ancestors of the Dmanisi population dispersed from Africa before the emergence of humans identified broadly with the H. erectus grade.

Influence of particle size of autogenous bone grafts on the early stages of bone regeneration: a histologic and stereologic study in rabbit calvarium

PURPOSE

The aim of this study was to investigate the influence of particle size of autogenous bone grafts on the early stages of bone regeneration.

MATERIALS AND METHODS

Bicortical skull bone defects were prepared in 15 rabbits (4 in each rabbit). Two defects were filled at random with either small (0.5 to 2 mm3) or large (10 mm3) autogenous bone particles. In addition, 1 defect was left unfilled (control defect). All defects were covered bicortically by expanded polytetrafluoroethylene membranes. The animals were divided randomly into 3 groups and sacrificed after 1, 2, and 4 weeks, respectively. Histologic and stereologic evaluations were performed after the sections were blinded.

RESULTS

No significant differences in total vessel surface area could be identified among the 3 groups. The total volume of newly formed bone in defects with small particles was larger and more mature compared to defects with large particles after 2 and 4 weeks. Furthermore, the resorption of small particles was more pronounced after 4 weeks, documenting a higher level of bone substitution compared to large particles.

DISCUSSION

The early stages of bone regeneration were influenced by the particle site of autogenous bone grafts.

CONCLUSION

The present study indicated that particles of 0.5 to 2 mm3 in size should be preferred to particles of 10 mm3 in size for bone grafting.

The morphology of the European miocene hominid frontal bone: functional, developmental and phylogenetic considerations

This paper re-interprets the morphology of fossil and extant hominid frontal bones in light of development, functional and phylogenetic considerations. It is argued that the suggested inclusion of Hispanopithecus and Ankarapithecus as members of the Ponginae (which has partly been based on frontal bone morphology) remains problematic as their similarity with other members of the Ponginae is likely the result of distinct developmental processes resulting in Hispanopithecus and Ankarapithecus sharing an anatomical analogy with this subfamily. Whether this can be used to argue against their inclusion within the Ponginae remains debatable, as we still do not appreciate degrees of developmental variability within and between taxa, nor their phylogenetic significance in closely related taxa. The frontal bone morphology as observed in Hispanopithecus and Ankarapithecus, however, suggests that they share a sister-group relationship. In terms of the Homininae, Graecopithecus is supported as a likely member of this subfamily, while Dryopithecus is considered as a primitive member of the Hominidae.

Bony orbital distances among the Filipino population

Six hundred and seventy seven radiographs were selected from the logs of films taken in a major hospital in Metro Manila, Philippines over the course of the previous year. Two hundred and eighty-eight female and 389 male, healthy Filipinos between the ages of birth and twenty years were selected based on the availability of a modified Waters' projection and lateral skull film taken at the same time. Measurements for the lateral orbital wall were made at the site of the suture on the medial surface of the zygomatic bone. The medial orbital wall measurement was the distance between the dacrya using a correction factor formula of CF = D-d/D where D is the target film distance and d is the object film distance (1). The actual bony measurements were calculated. The data was gathered and plotted according to sex and in age in years. Graphs were generated using SAS over a graph software. Lines were smooth using cubic spline technique developed by Reinsch with the smoothest value of 75 (2). The mean plus two, four, and six standard deviations were included in each of the curves.

Craniofacial anthropometry in a Turkish population

OBJECTIVE

To present norms and demonstrate the anthropometric variations in fronto-occipital circumference, inner and outer canthal distances, near and distant [far] anatomical interpupillary distance, canthal index, and circumference-interorbital index across age and sex in urban Turkish subjects.

PARTICIPANTS

Three thousand four hundred forty-eight subjects (1852 male, 1596 female) aged 7 to 40 years were included in this study.

METHODS

Three age groups were studied: children aged 7 to 15 years, young adults aged 16 to 25 years, and adults aged 26 to 40 years. Mean values for each measured parameter were determined at each age between 7 and 25 years. Subjects were also divided into nine age subgroups to observe the change of each parameter with advancing age.

RESULTS

The fronto-occipital circumference and outer canthal distance of males was significantly (p <.001) wider than females in all age groups. The near and distant interpupillary distances of male subjects were, on average, wider than the female subjects with greater differences with advancing age. Across all subjects aged 7 to 40 years, the mean of all measured parameters and calculated indexes of men and boys was significantly different from girls and women (p <.001). The mean for interpupillary distances in our study in both sexes were found to be similar to Arabian, Hong Kong, and British children; larger than those of Chinese, Black, Indian, and Caucasians; and smaller than those of Mexican children and a mixed European population.

CONCLUSION

This study clearly shows the anthropometric variation for fronto-occipital circumference, inner canthal distance, outer canthal distance, near and distant interpupillary distance, canthal index, and circumference-interorbital index with age. These developmental data and the normal values of these measurements in healthy subjects are useful for dysmorphologists in the early identification of some craniofacial syndromes, hyper- and hypotelorism, and congenital or posttraumatic telecanthus and of planning surgical intervention. We suggest that the comparison of craniofacial dimensions of a patient must be performed with normal standards specific for age as well as sex and race.

Superficial surgical landmarks for the frontal sinus

OBJECT

There is a lack of reports in the literature that contain descriptions of superficial anatomical landmarks for the identification of the internally located frontal sinus. Neurosurgeons must often enter the cranium through the frontal bone and knowledge of the frontal sinus is essential to minimize complications.

METHODS

Seventy adult cadaveric frontal sinuses were evaluated. Measurements included both the lateral and superior extent of the frontal sinus in reference to a midpupillary line, and the superior extent of the frontal sinus from the nasion. Frontal sinuses were found bilaterally in all specimens. The mean height of the frontal sinus superior to the nasion was 2.8 cm. In 71.4% and 74.3% of specimens the lateral extent of the frontal sinus was found to be medial to the left and right midpupillary line, respectively. Distances superior to a plane drawn through the supraorbital ridges at a midpupillary line included a mean of 2.5 mm for the left side and 1.8 mm for the right side.

CONCLUSIONS

Of 70 sinuses, none extended more than 5 mm lateral to a midpupillary line. At this same midpupillary line and at a plane drawn through the supraorbital ridges, the frontal sinus was never higher than 12 mm. Finally, in the midline the frontal sinus never reached more than 4 cm above the nasion. These measurements will assist surgeons who must manipulate the frontal bone.

The frontotemporal peripheral nerves. Topographic variations of the supraorbital, supratrochlear and auriculotemporal nerves and their possible clinical significance

The peripheral topography of the supraorbital (SON) and supratrochlear (STN) nerves and the superficial temporal branch of the auriculotemporal nerve (ATN) was investigated in 10 cadavers. The aim was to define the optimal locations for anaesthetic nerve blocks, as well as to help surgeons prevent nerve injuries. Specific measurements on the nerve "exits" in relation to defined landmarks are presented. The variability of the supraorbital notches and peripheral branching of the dissected nerves suggests several methods for anaesthetic blocks in cases of surgical and clinical head pain. The optimum injection site for a selective SON block is 20-30 mm from the midline (range 15-33 mm); reinjection at 30-50 mm from the midline might complete inefficient nerve block. For selective SON block the distance between the main SON and STN branches (mean 15.3 mm) should also be considered. The ATN is best blocked at a point located at the level with and 10-15 mm (range 8-20 mm) anterior to the upper origin of the helix. Separate exits for the medial and lateral SON branches were observed in eight of the 20 nerves examined. Twenty of the 28 exits were foraminae completed by bony or connective tissue. In many cases both the SON and STN ascended close to the associated artery: in six cases a tissue band covered the nerve and vessel at the orbital exit. Some of the observed structures associated with the nerve might be pain-generators, however the present study does not provide any evidence for such a hypothesis.