"Keystone" approach for intracranial nasofrontal dermoid sinuses

Nasofrontal dermoid sinus tracts that extend intracranially through the foramen cecum or ethmoid can be difficult to completely resect. Complete extirpation of nasofrontal dermoid sinus cysts is essential for effective treatment of this problem to minimize the chance of recurrence. The authors describe a new technique based on parasagittal osteotomies through the supraorbital bar, or bandeau, that ensures that the resection of the nasofrontal dermoid sinus cysts is complete. This technique also limits the size of the external nasal incision and enhances the surgeon's exposure of the anterior cranial base for resection of intradural extension. This approach also enhances exposure for the direct repair of the dura and the cranial vault.     

Hierarchical nature of morphological integration and modularity in the human posterior face

Morphological integration and modularity are important points of intersection between evolution and the development of organismal form. Identification and quantification of integration are also of increasing paleoanthropological interest. In this study, the "posterior face," i.e., the mandibular ramus and its integration with the associated midline and lateral basicranium, is analyzed in lateral radiographs of 144 adult humans from three different geographic regions. The null hypothesis of homogenously pervasive morphological integration among "posterior-face" components is tested with Procrustes geometric morphometrics, partial least squares, and singular warps analysis. The results reveal statistically significant differences in integration. Only loose integrative relationships are found between midline and lateral components of the basicranium, which may indicate the presence of at least two different basicranial modules. This modularity can be interpreted in terms of spatiotemporal dissociation in the development of those basicranial structures, and gives support to hypotheses of independent phylogenetic modifications at the lateral and midline basicranium in humans. In addition, morphological integration was statistically significantly stronger between the middle cranial fossa and the mandibular ramus than between the ramus and the midline cranial base. This finding confirms previous hypotheses of a "petroso-mandibular unit," which could be a developmental consequence of well-known phylogenetic modifications in coronal topology of the posterior face and base in hominoid evolution, related to middle cranial fossa expansion. This unit could be involved in later evolutionary tendencies in the hominid craniofacial system.     

Development of the supraorbital and mandibular lateral line canals in the cichlid,Archocentrus nigrofasciatus

The development of two of the cranial lateral line canals is described in the cichlid, Archocentrus nigrofasciatus. Four stages of canal morphogenesis are defined based on histological analysis of the supraorbital and mandibular canals. "Canal enclosure" and "canal ossification" are defined as two discrete stages in lateral line canal development, which differ in duration, an observation that has interesting implications for the ontogeny of lateral line function. Canal diameter in the vicinity of individual neuromasts begins to increase before ossification of the canal roof in each canal segment; this increase in canal diameter is accompanied by an increase in canal neuromast size. The mandibular canal generally develops later than the supraorbital canal in this species, but in both of these canals development of the different canal segments contained within a single dermal bone is asynchronous. These observations suggest that a dynamic process requiring integration and interaction among different tissues, in both space and time, underlies the development of the cranial lateral line canal system. The supraorbital and mandibular canals appear to demonstrate a "one-component" pattern of development in Archocentrus nigrofasciatus, where the walls of each canal segment grow up from the underlying dermal bone and then fuse to form the bony canal roof. This is contrary to numerous published reports that describe a "two-component" pattern of development in teleosts where the bony canal ossifies separately and then fuses with an underlying dermal bone. A survey of the literature in which lateral line canal development is described using histological analysis suggests that the occurrence of two different patterns of canal morphogenesis ("one-component" and "two-component") may be due to phylogenetic variation in the pattern of the development of the lateral line canals.     

Skull base tumors: a comprehensive review of transfacial swing osteotomy approaches

Numerous techniques have been proposed for the resection of skull base tumors, each one unique with regard to the region exposed and degree of technical complexity. This study describes the use of transfacial swing osteotomies in accessing lesions located at various levels of the cranial base. Eight patients who underwent transfacial swings for exposure and resection of cranial base lesions between 1996 and 2002 were studied. The mandible was the choice when wide exposure of nasopharyngeal and midline skull base tumors was necessary, especially when they involved the infratemporal fossa. The midfacial swing osteotomy was an option when access to the entire clivus was necessary. An orbital swing approach was used to access large orbital tumors lying inferior to the optic nerve and posterior to the globe, a region that is often difficult to visualize. Gross total tumor excision was possible in all patients. Six patients achieved disease control and two had recurrences. The complications of cerebrospinal fluid leak, infection, hematoma, or cranial nerve damage did not occur. After surgery, some patients experienced temporary symptoms caused by local swelling. The aesthetic result was considered good. Transfacial swing osteotomies provide a wide exposure to tumors that occur in the central skull base area. Excellent knowledge of the detailed anatomy of this region is paramount to the success of this surgery. The team concept is essential; it is built around the craniofacial surgeon and an experienced skull base neurosurgeon.     

Lateral subcutaneous brow lift and interbrow muscle resection: clinical experience and anatomic studies

The authors report consistent improvement in 65 patients with lateral brow ptosis by using a lateral subcutaneous brow lift at the temporal hairline. In 48 of these patients, vertical glabellar wrinkles were improved by the direct excision of procerus, corrugator, and orbicularis muscles through 3-mm medial brow incisions. Anatomic dissections in 10 cadavers and examinations of 50 skulls were used to study the location of the supraorbital and supratrochlear nerves. Dissections revealed that the supratrochlear nerve was never closer than 1.6 cm to the midline at the level of the supraorbital ridge. In no dissection was a supratrochlear foramen noted. Lateral subcutaneous brow lift was consistently successful in elevating the lateral brow. In no patient was nerve damage to the supraorbital nerve noted. In most patients, the temporal hairline was improved by excising a triangle of balding scalp. Through 3-mm medial brow incisions, the interbrow musculature can be excised by using a small rongeur in an area 3.2 cm wide without risk of nerve damage, improving vertical glabellar wrinkles.     

The craniofacial skeleton in anencephalic human fetuses. I. Cranial floor

Twelve anencephalic and four normal fetuses 26 to 40 weeks gestational age were compared by anatomic, radiographic and histologic methods in order to gain information concerning morphogenesis. In the anencephalics, alterations located within the body of the sphenoid bone led to a reduced cranial floor angle and a more vertical clivus. The reduced lateral extension of the lesser and greater wings of the sphenoid constricted the anterior and middle cranial fossae respectively. The posterior cranial fossa tended to have an increased transverse dimension related to the supraoccipital and exoccipital bone orientation. The increased anterior and inferior position of the lateral end of the petrous temporal ridge was positively correlated with the degree of dorsal schisis in the anencephalics. Alterations in the size, form, or duration of the neural functional matrix are suggested as the cause of changes in the cranial floor.     

Unilateral exophthalmos caused by an anterior ethmoidal meningoencephalocele.

A case of unilateral enophthalmos in a 1-year-old child is presented. This was caused by a meningoencephalocele that originated in the anterior cranial fossa and protruded into the orbit through a bony defect at the junction of the frontal and ethmoid bones at the site of the anterior ethmoid canal. This meningoencephalocele was reduced, and the dura was repaired with a temporalis fascia graft. A split calvarial bone graft was inserted into the floor of the orbit, and lateral canthal ligament elevation completed the operative correction.     

Growth changes in measurements of upper facial positioning

Growth changes in the position of the midline upper face are examined for samples of Pan troglodytes, Gorilla gorilla, and modern humans. Horizontal and vertical distances between nasion and the anterior end of the cribriform plate are plotted against stage of dental development. Kendall's nonparametric correlations between facial positioning and stage of dental development are tested for significance. In African apes, the upper face becomes more projecting and positioned higher relative to the anterior cranial base. The extent of this horizontal and vertical separation reflects primarily facial size. In modern humans, the upper face becomes more projecting but is relatively stable in its vertical position. Comparison of Pan and modern human crania in the youngest dental age category indicates that the upper face of modern humans is positioned lower early in postnatal life. The position of the upper face (glabella) relative to the anterior and posterior cranial base is presented for several fossil hominid crania. The fossil crania are similar to Pan and modern humans in facial projection relative to the anterior cranial base. However, glabella is positioned low in the fossil crania. Total facial projection (relative to hormion) for Sts 5 is similar to the mean for Gorilla. Fossil Homo and robust australopithecine crania display very projecting upper faces. We suggest that the upper face of Homo is projecting due to the length of the anterior cranial fossa, while robust australopithecines possess a thick frontal bone.     

Interspecific perspective on mechanical and nonmechanical models of primate circumorbital morphology.

Linear dimensions and angular orientations of the browridge, postorbital bar, and postorbital septum were obtained from a representative series of primates and compared with variables associated with several nonmechanical and biomechanical/mechanical models put forward to explain the form and function of the circumorbital region. Analyses of the results indicate that face size is the primary determinant of variation in primate circumorbital morphology. Anteroposterior browridge thickness is correlated with neural-orbital disjunction among anthropoid primates, but not among prosimians. This difference appears related to differences in the construction of the upper face and anterior cranial fossa between prosimians and anthropoids. Little support is demonstrated for the anterior dental loading model of browridge development. Mediolateral postorbital bar width and (to a lesser degree) browridge height are correlated with neurofacial torsion during mastication and variation in masticatory muscle size. These analyses further suggest that since circumorbital structures (especially the browridges) are located the farthest away from the chewing apparatus, they are least affected by masticatory stresses.     

四川自贡大山铺孙氏鳄属(Sunosuchus)一新种

记述了在四川自贡大山铺发现的孙氏鳄一新种———蜀南孙氏鳄 (Sunosuchusshunanensissp .nov .)。新种窄长的吻部 ,小的颅顶平台 ,额骨沿中线具一纵嵴 ,一对裂隙状的前腭孔位于眶下孔之前方 ,方骨腹面的嵴B特别发育等 ,与孙氏鳄的其他种很相似 ,但新种的吻部特别窄长 ,为吻后部长度的 3倍 ,上颌凹特别发育 ,颅顶平台短而宽 ,颞间部宽度大于眶间部宽度 ,泪骨在眼眶前缘处隆起成嵴 ,下颞孔小 ,呈裂隙状 ,鳞骨侧缘不增厚 ,也无附着上耳盖的沟嵴状构造 ,基枕骨侧缘和外枕骨内腹缘具一明显的隆嵴等 ,与孙氏鳄的其他种有明显区别     

中国原大羚化石的再研究

在研究新发现化石材料及对已有标本重新观察的基础上,讨论中国晚中新世至早上新世原大羚(?Protoryx)的系统分类位置。依据头骨、角心和牙齿等方面所具有的独特性状,建议把发现于中国北方曾归入?Protoryx的种类从旧大陆同时代或时代稍早的Protoryx Major, 1891中分出,另立2个新属:以?Protoryx yushensis Teilhard&Trassaert,1938为属型种的华北羚(Huabeitragus gen．nov．)和以?Protoryx shansiensis Bohlin,1935为属型种的粗壮羚(Macro- tragus gen．nov．)。华北羚体型中等大小,头骨窄长,颅轴与面轴夹角近直角,弯曲发生在角前的额部,眶上孔小,分开远,脑颅部短窄,间顶骨长方形,基枕骨方形,没有中纵沟或中嵴,角心长而纤细,基部靠近,向上分散度大,基部横断面近三角形,具前棱。Macrotragus头骨大而粗壮,其弯曲发生在角心基部之间的额面,弯曲度大于直角;角基之间的额中缝隆起呈脊;脸部宽;眶前窝浅;眶下孔后缘位于P3之上。眼眶向头骨两侧突出不明显,其前缘位于M3后缘之后;脑颅部短宽,呈简状,背面稍凸;枕面高、呈半圆形;基枕部为长方形或梯形,具中纵沟和弱的中纵脊;卵圆孔大,面向侧方;角心大而粗壮,内外侧扁,无棱,基部紧靠,向上的分散度小,基部横切面为椭圆形。无角后窝。前臼齿列退化。这两个属之间的主要不同在于前者的个体较小;角心较细弱,向上分散度大(前面观),具前棱,基部横切面呈次三角形;头骨窄,其弯曲位置靠前,弯曲接近90°;脑颅部窄;枕面平,为低矮的长方形;基枕部呈方形,面平,无中纵沟和中纵脊,前、后节结不发育和卵圆孔相对小等。在系统位置上,它们可能属于山羊亚科(Caprinae)。     

Radical forehead remodeling for craniostenosis

A normal forehead has two parts, shaped differently: (1) the lower part (corresponding to the supraorbital rim and glabellar area) set at a steep angle to the nose; (2) the upper part, sloping gently backward. To reproduce this normal anatomy in cases of cranostenosis affecting the frontal area, we found it essential to mobilize and reshape a supraorbital bar of bone and to transfer a suitable piece of the cranial vault in one piece to make a new upper forehead. By this method we have treated 18 patients with oxycephaly since 1973, with good results. We have also operated on babies with craniostenosis to try to solve simultaneously the functional and the cosmetic problems. In faciocraniostenosis, there are dominant malformations at the base of the skull, but an isolated frontal advancement of two cm has produced gratifying early results.     

An analysis of Le Fort I maxillary advancement in cleft lip and palate patients.

We present a series of 24 consecutive cleft lip and palate patients aged 16 to 46 years (mean age 27 years) who underwent Le Fort I maxillary advancement by the senior author over the past 8 years. Two groups, one of 12 patients with wire fixation and one of 12 patients with miniplate fixation, were evaluated. Each group had 10 unilateral and 2 bilateral clefts. All patients were grafted with autogenous bone (8 cranial, 14 iliac, and 2 mandibular). Horizontal advancement was 3 mm to 2 cm (with a mean of 7.8 mm). Vertical movement ranged from a shortening of 5 mm to a lengthening of 1.3 cm (mean 2.3 mm of lengthening). The amount and timing of relapse were compared in both the horizontal and vertical dimensions. The plated group was more stable in both the horizontal and vertical dimensions (p < 0.05). No significant skeletal relapses occurred after the first year. Statistically significant dental relapse occurred only in the wired group. Three patients developed transverse collapse of the small maxillary cleft segment, and four developed incisor angulation to compensate for maxillary skeletal relapse. The presence of a pharyngeal flap at the time of advancement appeared to increase relapse in both horizontal and vertical dimensions (p < 0.03), but there were too few patients (7 of 24) with pharyngeal flaps to prove this conclusively. We also concluded that pterygomandibular grafting is not necessary to achieve excellent results using miniplate fixation; autogenous grafting of the anterior maxillary osteotomy alone provides the necessary stability.     

滇东中泥盆统的节甲鱼类化石

本文记述了节甲鱼类中称为北极鱼类的三个新属种:Exutaspis megista,Kunmingolepislucaowanensis,Yangaspis jinningensis,化石分别采自武定海口组(广义),海口和晋宁的海口组。代表我国中泥盆世该类化石鱼类的首次记述。     

The extended trapezius musculocutaneous flap for cranio-orbital facial reconstruction

The use of the extended posterior trapezius muscle skin flap for cranio-orbital facial reconstruction is presented. Its enormous arc of rotation allows it to reliably reconstruct massive defects of the upper face with the orbit at the center of the defect; i.e., this flap will reach well beyond the supraorbital rim and across the midline. Its application for the immediate reconstruction of massive deformities following resection of tumors of the orbit and cranial base appears justified and helps avoid the major morbidity normally associated with such resections.     

Function of the mammalian postorbital bar

Complete postorbital bars, bony arches that encompass the lateral aspect of the eye and form part of a circular orbit, have evolved homoplastically multiple times during mammalian evolution. Numerous functional hypotheses have been advanced for postorbital bars, the most promising being that postorbital bars function to stiffen the lateral orbit in taxa that have significant angular deviation between the temporal fossa and the bony orbit. Without a stiff lateral orbit the anterior temporalis muscle and fascia potentially would pull on the postorbital ligament, deform the orbit, and cause disruption of oculomotor precision. Morphometric data were collected on 1,329 specimens of 324 taxa from 16 orders of extant eutherian and metatherian mammals in order to test whether the orientation of the orbit relative to the temporal fossa is correlated with the replacement of the postorbital ligament with bone. The allometric and ecological influences on orbit orientation across mammals are also explored. The morphometric results corroborate the hypothesis: Shifts in orbit orientation relative to the temporal fossa are correlated with the size of the postorbital processes, which replace the ligament. The allometric and ecological factors that influence orbit orientation vary across taxa. Postorbital bars stiffen the lateral orbital wall. Muscle pulleys, ligaments, and other connective tissue attach to the lateral orbital wall, including the postorbital bar. Without a stiff lateral orbit, deformation due to temporalis contraction would displace soft tissues contributing to normal oculomotor function.     

Bending but not breaking the supraorbital bar

Surgical bending or contouring of the supraorbital bar may cause inadvertent fractures during craniofacial surgery. Wires may be placed in the bony segments themselves to facilitate reshaping with the Tessier rib bender. The wires are especially helpful in stabilizing the more acute curve at the lateral orbital rim.     

Frontal sinus fractures: guidelines to management

The appropriate management of frontal sinus fractures is controversial. Experience with 78 frontal sinus fractures over a 9-year period was reviewed, and the fractures were classified into anterior wall, anterobasilar, and frontal skull fracture extensions. The presence of a concomitant CSF leak or an air-fluid level in the sinus was a diagnostic clue of posterior wall involvement. Ablation or obliteration of the fractured frontal sinus is not necessary. Primary reconstruction of the sinus and nasofrontal duct drainage constitute the preferred treatment. "Cranialization" of a severely damaged sinus is performed by excision of the posterior wall plugging of the nasofrontal duct and reconstruction of the anterior wall. Reconstruction of the anterior wall with primary bone grafting may be necessary in selected patients.     

Meningeal arteries in rhesus macaques (Macaca mulatta): implications for vascular evolution in anthropoids.

The branching patterns of meningeal arteries are reported for 200 endocast hemispheres representing rhesus monkeys (Macaca mulatta) of known cranial capacity. We detect five basic patterns for the branching of the anterior division of the middle meningeal artery and its relationship with the anterior meningeal artery. These results confirm and elaborate trends published for much smaller samples that were based on direct dissections of rhesus monkey arterial patterns. The most common pattern is that in which the anterior meningeal artery dominates the blood supply above the rostral part of the middle cranial fossa. Analysis of cranial capacities reveals that presence of this pattern on both sides of endocasts is associated with increased cranial capacity. When studied in light of published reports of anatomical dissections of cranial arteries in apes and human embryological data, the anterior meningeal artery in rhesus monkeys appears to be a possible homologue of the lacrimal meningeal artery in apes and the anterior branch of the middle meningeal artery in humans. This finding provides a step towards understanding cranial vasculature homologies that may be useful for accurately scoring the branching patterns of the meningeal arteries in monkeys, apes, and humans.