Effects of annular cranial vault modification on the cranial base and face

Artificial modification of the cranial vault was practiced by a number of prehistoric and protohistoric populations, frequently during an infant's first year of life. We test the hypothesis that, in addition to its direct effects on the cranial vault, annular cranial vault modification has a significant indirect effect on cranial base and facial morphology. Two skeletal series from the Pacific Northwest Coast, which include both nonmodified and modified crania, were used: the Kwakiutl (62 nonmodified, 45 modified) and Nootka (28 nonmodified, 20 modified). Three-dimensional coordinates of 53 landmarks were obtained using a diagraph, and 36 landmarks were used to define nine finite elements in the cranial vault, cranial base, and face. Finite element scaling was used to compare average nonmodified and average modified crania, and the significance of the results were evaluated using a bootstrap test. Annular modification of the cranial vault produces significant effects on the morphology of the cranial base and face. Annular modification in the Kwakiutl resulted in restrictions of the cranial vault in the medial-lateral and superior-inferior dimensions and an increase in anterior-posterior growth. Similar dimensional changes are observed in the cranial base. The Kwakiutl face is increased anterior-posteriorly and reduced anterior-laterally to posterior-medially. Similar effects of modification are observed in the Nootka cranial vault and cranial base, though not in the face. These results demonstrate the developmental interdependence of the cranial vault, cranial base, and face.     

Genetic profile of pNOB8 from Sulfolobus: the first conjugative plasmid from an archaeon

Recently, children born small for gestational age (SGA) with a catch-up growth failure, have been selected for high dose growth hormone (GH) treatment. In order to gain greater insight concerning dentofacial growth and maturation of these patients, and to evaluate the possible effects of high does GH administration on facial structures, craniofacial growth and dental maturation were evaluated in short SGA persons. Seventy-seven cephalograms and orthopantomograms were available from 48 subjects, aged between 2 and 32 years. Craniofacial growth was assessed by calculating age- and gender-specific standard deviation scores (SDS) for eight linear and five angular measurements. Tooth formation was evaluated by means of a dental delay score (i.e. dental age minus chronological age). The SDS for craniofacial growth measurements for the lateral aspect showed a short anterior cranial base (-1.8 SDS), a small retropositioned mandible (< or = -1.7 SDS) and a small maxilla (-1.5 SDS); a high mandibular plane angle (+1.9 SDS) and a wide cranial base angle (+1 SDS). These findings result in a small retrognathic face with a relatively increased lower anterior face height (+1.7 SDS). In contrast to skeletal maturation, dental age was not delayed. The general growth retardation is, apparently, reflected to a differential extent within the craniofacial complex, while dental maturation appears to be a distinct process tightly linked to chronological age, and independent of general growth and bone age.     

Human fetal pituitary gland in holoprosencephaly and anencephaly

The normal prenatal development of the human pituitary gland and the gland-supporting sella turcica has recently been investigated. The sella turcica area constitutes a developmental boundary area in the cranial base. Posterior to the area the cranial base has developed close to the notochord, and anterior to the region the cranial base development is dependent chiefly on neural crest cell migrations. In the present study the sella turcica region was analyzed in two fetuses with holoprosencephaly (cyclopia and median cleft) and four fetuses with anencephaly combined with rachischisis in the neck region (GA 16-20 weeks). The sella turcica region was investigated radiologically and histologically. Adenohypohyseal gland tissue was localized by immunohistochemical hormonal marking. In both types of malformation an open craniopharyngeal canal was seen in the base of the sella turcica with adenohypophyseal glandular tissue located in the sella turcica, in the canal, and in the pharyngeal connective tissue at the external side of the cranial base. In conclusion, severe malformations of the pituitary gland occur in both holoprosencephaly, which is a polytopic field defect located anterior to the sella turcica, and in anencephaly associated with notochordal insufficiency posterior to the sella turcica. This might indicate that the sella turcica area, bounding different developmental fields, is involved in various craniofacial malformations. It is consequently recommended that examination of the pituitary gland should become a part of the routine autopsy of prenatal material when malformations in the face, brain, and cranial base occur.     

Sphenoid shortening and the evolution of modern human cranial shape

Crania of 'anatomically modern' Homo sapiens from the Holocene and Upper Pleistocene epochs differ from those of other Homo taxa, including Neanderthals, by only a few features. These include a globular braincase, a vertical forehead, a dimunitive browridge, a canine fossa and a pronounced chin. Humans are also unique among mammals in lacking facial projection: the face of the adult H. sapiens lies almost entirely beneath the anterior cranial fossa, whereas the face in all other adult mammals, including Neanderthals, projects to some extent in front of the braincase. Here I use radiographs and computed tomography to show that many of these unique human features stem partly from a single, ontogenetically early reduction in the length of the sphenoid, the central bone of the cranial base from which the face grows forward. Sphenoid reduction, through its effects on facial projection and cranial shape, may account for the apparently rapid evolution of modern human cranial form, and suggests that Neanderthals and other archaic Homo should be excluded from H. sapiens.     

Reconstruction of upper cranial and cranial base defects utilizing the scalping flap

Reconstruction of midfacial defects by means of a scalping flap has been widely practiced and described in the literature. The advantages of the flap are familiar to surgeons who perform extirpations and reconstruction of the head and neck and include contiguous availability, simplicity of application, and a robust and redundant blood supply. Despite these merits, the flap has not been widely used for reconstructions of large anterior cranial defects or defects of the cranial base. A retrospective review of 11 patients who underwent reconstructions between 1990 and 1995 was performed. In each case, a reconstruction of a large anterior cranial or cranial base defect was carried out. The resulting soft-tissue defect was restored via the scalping flap. In six cases, this was carried out in a single procedure. In five cases, flap division and insetting were carried out in a subsequent procedure, following a 1- to 2-week delay. In all cases, the extirpation and reconstruction were well tolerated, and the average time of hospitalization was 5.9 days and ranged from 3 to 11 days. No major surgical complications occurred. One of 11 patients had a minor complication not requiring surgical intervention. There was one recurrence of a cranial base tumor approximately 2 years following the initial resection and reconstruction. In all cases, the final aesthetic and functional results were acceptable to excellent. Follow-up ranged from 11 months to 5 years. In conclusion, the scalping flap can be effectively utilized for soft-tissue coverage in the reconstruction of anterior cranial and cranial base defects. Use of this simple and versatile flap in craniofacial reconstruction is well tolerated and is associated with a low morbidity, a good aesthetic result, and a short hospital stay.     

Comparative study of craniofacial morphology in Japanese and Australian aboriginal populations

A metric study of 71 Japanese and 106 Australian aboriginal precontemporary crania was undertaken using direct measurements and cephalograms. Compared with Australian aboriginals, the Japanese are characterized by smaller cranial length, cranial base length, nasal floor length, palatal length, mandibular dimensions (except symphysis height), facial depth, posterior face height, and facial profile angle and larger cranial breadth and height, maxillary breadth, palatal breadth, anterior face height, and occlusal and mandibular plane angles. These differences confirm the previously described brachycephalic tendency in aboriginals and the dolichocephalic form in the Japanese. The differences are also consistent with the expected functional differences between the Australian aboriginal hunter-gatherer group masticating more resistant food with larger, more anteriorly located, more powerful masseter muscles and the Japanese group masticating less resistant food with correspondingly less robust masticatory musculature. The results highlight the differences in craniofacial morphology between groups with different genetic backgrounds subjected to significantly different environmental influences.     

Complications of craniofacial surgery for tumors involving the anterior cranial base

OBJECTIVE: To evaluate the risk factors for postoperative complications among patients undergoing craniofacial resection for the treatment of anterior cranial base tumors, a retrospective analysis of patients treated in University of Tokyo Hospital between September 1987 and November 1996 was conducted. METHODS: Twenty-nine patients underwent 33 craniofacial resections for tumors involving the anterior cranial base. Twenty-three of the 29 patients had malignant tumors and 6 patients had benign tumors. Anterior craniofacial resection was performed using a combination of intracranial and extracranial approaches. Radiotherapy and neoadjuvant chemotherapy were administrated to some patients. RESULTS: Severe intracranial infections were more common among patients who underwent partial frontal lobectomies (P < 0.03). These infections occurred only in patients who had been treated previously with a craniotomy (P < 0.02) and a total radiation dose of > or =60 Gy (P = 0.06). Neither management of the extracranial structures nor methods of reconstruction of the cranial base showed significant correlation with major postoperative complications. CONCLUSION: Compared with previous reports, craniofacial resection has become a relatively safe and effective procedure for the treatment of tumors involving the anterior cranial base. However, additional care should be taken with patients who have experienced a previous craniotomy, frontal lobe involvement, or radiotherapy with a total dose of > or =60 Gy.     

Analytical evaluation of complex anterior approaches to the cranial base: an anatomic study

OBJECTIVE: The purpose of the present study was to evaluate the anatomic areas of the cranial base exposed by different complex anterior approaches. METHODS: Using 20 embalmed cadaveric heads, we executed five different anterior approaches, i.e., Le Fort 1 approach with splitting or down-fracturing of the hard palate, extended maxillectomy, median mandibulotomy with glossotomy, and mandibular swing transcervical approach. Each approach was performed a minimum of three times. The areas of the intra- and extracranial cranial base exposed by each approach were analytically examined by using a numerical grading system to assess the exposure of major anatomic and neurovascular structures. RESULTS: Good exposure of the midline compartment of the cranial base was provided by the median mandibulotomy with glossotomy and by the Le Fort 1 approach with splitting of the hard palate, whereas the mandibular swing transcervical and extended maxillectomy approaches provided good exposure of the lateral compartment of the cranial base. CONCLUSION: Use of the numerical grading system allowed quantification of the exposure afforded by each approach, with respect to the different compartments (midline and lateral) of the intra- and extracranial cranial base, highlighting the differences among the approaches examined.     

Decision model for the acute treatment of mania

The authors present a case of foreign body retention, following car accident, localized on superior medial corner of the right orbit. The traumatic impact, involving endo-orbital structures, owing to the peculiar direction of the foreign body, caused a fracture in the anterior cranial base and laceration of the dura madre. As the anatomical structures involved did not concern only the MaxilloFacial district, the choice of the protocol to be applied to the patient was taken in accordance with the neurosurgical équipe. An intra cranial surgical approach has allowed to remove, by retrograding the foreign body on its trajectory path, in order not to injure further the already damaged structures involved. Then the tissues have been reconstructed; in particular, the anterior cranial base was restored through the use of pericranial strip. This technique is the elective surgical treatment in lesions of such small entity, as it is able to grant a solid support to the overhanging cerebral parenchyma. Besides, this reconstruction technique provides a complete protecting isolation of the ocular globe from compressive and pulsative phenomena, due to the neurocranial adjacent structures. With this technique, after a 8 month's follow-up. The patient has obtained optimum functional and aesthetic results.     

Metopic synostosis: in favour of a "simplified" surgical treatment

Metopic synostosis is a relatively simple form of craniosynostosis, resulting from premature fusion of the metopic suture. In this pathology different degrees of dysmorphia of the anterior cranial fossa and the presence of associated anomalies of the skull might enable specific subgroups to be identified. Since most functional and cosmetic anomalies benefit from early surgical treatment, over the last few years neurosurgeons have been forced to elaborate less drastic, but nonetheless effective, surgical techniques. In the present report we analyze the surgical results obtained in a series of 62 infants with trigonocephaly operated on within their 1st year of life. Patients were subdivided into two groups (group I: 8 patients; group II: 54 patients) according to the specific dysmorphic characteristics of the frontal bone and anterior cranial fossa, and the presence of compensatory deformities affecting the anterior cranial base and temporo-parietal region. All the patients were treated using one of two relatively simple surgical techniques (procedure A: inversion of two hemifrontal bone flaps--48 cases; procedure B: the "shell" operation--14 cases). Both surgical procedures appeared to be effective, allowing adequate functional and cosmetic correction of the cranial deformity. In patients operated on following procedure B surgical time and blood loss were dramatically reduced. Long-term outcomes were satisfactory in all cases, irrespective of the surgical technique used. In the group II patients, however, progressive normalization of the interorbital distance was constantly observed, suggesting a different degree of stenotic involvement at the level of the anterior cranial base in these patients.     

Craniofacial and dental characteristics of Silver-Russell syndrome

We found significant differences in a craniometric, cephalometric, and dental study of 19 Silver-Russell syndrome patients (13 without growth hormone treatment) with appropriate controls. Although head circumference was normal for age, head length was increased, while cranial and facial widths and facial heights were reduced. Posterior facial height, posterior cranial base length, cranial base height, and mandibular body size were significantly smaller than in healthy children of the same height. Articulatory speech disorders were common. Enamel defects pointed to an early prenatal insult. Delayed dental age and small mandibular and cranial base dimensions support the possibility of physiological growth hormone deficiency in many Silver-Russell syndrome children; however, facial soft tissue structures were strikingly different from those observed in classical growth hormone deficiency.     

Transnasal endoscopic excision of midline nasal dermoid from the anterior cranial base

We recommend that every patient with a midline nasal dermoid be evaluated preoperatively by fine-cut CT scan, in the axial and coronal planes, using both bone and soft-tissue algorithms. Because of CT limitations for assessing soft tissue at the cranial base, a complementary thin-section, high-resolution, multiplanar MRI scan should be considered. Transnasal endoscopic excision of midline nasal dermoid should be used if the dermoid is located within the nasal cavity, and there is minimal or no cutaneous involvement. This approach can be combined with a short vertical midline lenticular excision of a cutaneous punctum. Vertical cutaneous excision should be limited; the best location is the nasal tip. Vertical nasal scars over the bony pyramid invariably widen no matter what intradermal suture is used. Endoscopic removal should be considered even if preoperative radiologic studies show extension to the anterior cranial fossa. Endoscopic excision could also be used to resect a dermoid extending between the dural leaves of anterior fossa. However, a combined intra-extracranial approach is necessary if the dermoid is in the falx cerebri. We agree with other authors that frozen sectioning the superior margin of the specimen should be done to ensure that there is no intracranial extension. Valsalva maneuver during endoscopic visualization of the cranial base is a valuable means of ruling out a cerebral spinal fluid leak.     

The clinical assessment of attachment in children under five

Dural arteriovenous malformations (AVMs) are considered to be acquired lesions that develop secondary to venous obstruction, which sometimes happens in head trauma. However, there has been a report of an anterior cranial fossa dural AVM that occurred independently of a history of head trauma, and there has been speculation that these malformations are congenital. The authors recount their experience with a patient who had an anterior cranial fossa dural AVM that was discovered incidentally. The lesion was fed by the bilateral anterior ethmoidal arteries and drained into the superior sagittal sinus via frontal cortical veins. The patient had a history of severe head trauma that had occurred 30 years earlier. This is the first case report in which a previous head trauma is strongly believed to be the cause of an anterior cranial fossa dural AVM. The authors postulate that anterior cranial fossa dural AVMs can develop secondary to a head trauma.     

Surgery of the anterior skull base

Inflammatory disease of the frontal, ethmoid, and sphenoid paranasal sinuses may extend to the adjacent anterior skull base and then intracranially. The potential for this serious complication of sinus disease must be recognized by the primary otolaryngologist-head and neck surgeon, and alternative management strategies must be taken once it is diagnosed. Topics discussed in this article include cranial anatomy, surgical techniques and variations, complications, and special considerations.     

Pyogenic liver abscesses: a comparison of older and younger patients

The purpose of the present study was to analyze the morphology of the sella turcica in children born with myelomeningocele. Profile radiographs from 16 children (nine females and seven males) born with myelomeningocele were analysed. The contour of the anterior wall of the sella turcica in myelomeningocele patients, instead of following the normal cranio-caudal direction, was always in an obliquely antero-posterior direction. The sella turcica thus appeared broad cranially with a diverging anterior wall, or with both diverging anterior and posterior walls. This appearance gave and impression of a wide sella turcica in myelomeningocele with less depth than normal. The investigation has drawn attention to the fact that congenital malformations in the axial skeleton, even though, as in the case of myelomeningocele, they are located far from the cranial base, may have manifested themselves in the cranial base as well. The pathogenetic relationship between these manifestations is to be found in the early embryonic structure, the notochord. With the concept of embryological developmental fields, defined as areas with a common developmental origin, such as the notochordal field involved in myelomeningocele, new ways seem to be emerging for an improvement of aetiologically based diagnosis and treatment.     

Transverse glabellar flap for obliteration/isolation of the nasofrontal duct from the anterior cranial base

Management of fractures involving the nasofrontal duct region of the frontal sinus has focused on preserving function when possible or obliterating the sinus and duct when fracture patterns potentiate ductal obstruction and possible transcranial seeding of bacteria. When frontal sinus preservation is in doubt, controversy surrounds the use of cranialization versus obliteration, and the method of obliteration. Perioperative and late postoperative infections are uncommon, but their occurrence jeopardizes an often complex reconstruction and can be life threatening. This paper describes the design and indications for a pedicled transverse glabellar muscle flap for obliteration of the nasofrontal duct, thereby isolating the anterior cranial base from the aerodigestive system. This vascularized muscle flap utilizes the corrugator supercilii and procerus muscles, which are introduced into the sinus via a small, surgically created window in the superomedial orbital wall without disturbing the central facial aesthetic contours. Six patients with comminuted fractures at the nasofrontal duct level associated with displaced posterior frontal sinus fractures have been treated with the transverse glabellar flap. Follow-up ranges from 8 to 30 months. There have been no early or late postoperative complications. The transverse glabellar flap is a reliable and versatile method of partitioning the upper aerodigestive tract from the anterior cranial base with vascularized tissue, thus minimizing the risk of infectious complications. The resulting donor site deformity is more acceptable than that seen with the traditional pedicled galeal frontalis flap.     

Implementation of guidelines for No-CPR orders by a general medicine unit in a teaching hospital

Improvements in reconstruction of the skull base have made craniofacial surgery safe. Reconstruction of the anterior skull base must provide a seal between the cranial cavity and upper respiratory tract, as well as offer structural support for the brain. A wide variety of local flaps have been designed. The choice of flap in individual cases depends on the location and size of the defect. We report a reconstructive technique for the anterior skull base with vertical median forehead flaps which we used to treat two patients, one patient with adenocarcinoma and the other with leiomyosarcoma. Both were lesions of the ethmoid sinuses and nasal cavity.     

Magnetic resonance images and histology of the spheno-occipital synchondrosis in young monkeys (Macaca fuscata)

Magnetic resonance images and the histology of spheno-occipital synchondrosis were examined in young monkeys in order to compare the magnetic resonance images with their histologic observations. In serial magnetics resonance images of posterior cranial base, the spheno-occipital synchondrosis showed a low signal zone with unclear boundaries, running through the posterior cranial base perpendicularly to the clivus. The zone was always interposed between nonsignal zones. These observations were the same as those in young juvenile human beings. The histologic sections also revealed that the low signal zone was really the spheno-occipital synchondrosis, which consisted of hyaline cartilage and that the nonsignal zones were bone tissues. The chondroblasts in the spheno-occipital synchondrosis were arranged bipolarly. Intense alkaline phosphatase activity was located in the areas along the bone. Tetracycline labeling was also noticed in the bone formed in the endochondral ossification. These results suggest that magnetic resonance imaging enables us to observe the spheno-occipital synchondrosis in the posterior cranial base and also to elucidate its influences on the growth of maxilla and mandible in the future.     

Hemifacial dismasking flap for anterior skull base tumor--technical note

A new approach to malignant tumor in the anterior skull base using a hemifacial dismasking flap is described. A bicoronal incision is extended unilaterally down to the neck, degloving the craniofacial tissue to widely expose the skeleton underneath, allowing easy resection of an extensive tumor without postoperative scarring of the face. This method has been used successfully on five patients.     

Anterior and middle cranial fossa in traumatic brain injury: Relevant neuroanatomy and neuropathology in the study of neuropsychological outcome.

The frontal and temporal lobe regions of the brain have a high vulnerability to injury as a consequence of cerebral trauma. One reason for this selective vulnerability is how the frontal and temporal regions are situated in the anterior and cranial fossa of the skull. These concavities of the skull base cup the frontal and temporal lobes which create surface areas of contact between the dura, brain, and skull where mechanical deformation injures the brain. In particular, the sphenoid ridge and the free-edge of the tentorium cerebelli are uniquely situated to facilitate injury to the posterior base of the frontal lobe and the anterior pole and medial surface area of the temporal lobe. Three-dimensional image reconstruction with computerized tomography and magnetic resonance imaging are used to demonstrate the vulnerability of these regions. How neuropsychological deficits result from damage to these areas is reviewed and discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)