Effects of tensile forces on the expression of type III collagen in rat interparietal suture

The aim was to investigate the direct contribution of mechanically induced stress to synthesized type III collagen in the interparietal suture. Twenty 4-week-old male rats were used as experimental animals. An activated expansion spring was placed across the interparietal suture. After expansion, the parietal bones including the suture were dissected and immunostained for type I and III collagens. Also, a three-dimensional model of the interparietal suture was developed to analyze stress during expansion. The localization of type III collagen in the suture was dependent upon the duration of expansion. Although the control suture exhibited no or little reactivity for type III collagen, it was observed as early as 15 h of expansion in the cambial layers, and was distributed throughout the suture at 50 h of expansion. The time-dependent distribution of type III collagen was fully consistent with that of tensile stresses calculated by the use of a three-dimensional finite-element model. It was concluded that the increases in tensile stress are associated with the synthesis of type III collagen in the suture.

Changes in the biomechanical properties of the rat interparietal suture incident to continuous tensile force application

This study was designed to investigate the relation between the biomechanical behaviour of rat interparietal sutures and expansion forces placed on them. Thirty-five 4-week-old rats were divided into four groups, a control group and three experimental groups subjected to mechanical expansion of the interparietal sutures with a tensile force for 15, 30 and 50 h. After expansion, the parietal bones, including the interparietal suture, were dissected as specimens for tensile tests. Under tension, the relaxed stress-strain plots in the control group could be better fitted by a power of 2.00, and the relaxed moduli were 0.64 and 4.51 MPa at the lower and the higher applied strains, respectively. An initial fall in the relaxed moduli at 15 h of expansion was followed by an increase over time. It is therefore suggested that the biomechanical behaviour of the interparietal sutures is influenced by the duration of an external force.

Calcified falx meningioma

A totally calcified mid third falcine meningioma in an elderly male patient is presented. An uneventful enmasse excision was performed. Advantages of positioning on ipsilateral side for paramedian extracerebral lesions are highlighted.

Hypertrophic osteoarthropathy in a child with nasopharyngeal carcinoma

We report a 13-year-old boy with nasopharyngeal carcinoma, skull metastases and hypertrophic osteoarthropathy. Although the metastases and the primary tumour responded well to chemotherapy, hypertrophic osteoarthropathy persisted during follow-up.

Spontaneously infected cephalohematoma: case report and review of the literature

Spontaneously infected cephalohematomas are rare occurrences; only five cases have been reported previously. Uninfected cephalohematomas are common and usually resolve without treatment. However, physicians should be aware that cephalohematomas are potential sites for infection and may require aspiration for diagnosis and treatment. Untreated infected cephalohematomas may lead to osteomyelitis, epidural abscess, or subdural empyema. We present a case of a spontaneously infected cephalohematoma with an associated osteomyelitis which was successfully managed with drainage and long-term antibiotics. A review of the literature is also presented.

Extradural meningioma in the left fronto-temporo-parietal region

A case of a 47-year-old male patient who presented with a history of complaints of headache, vertigo and an expanding painful swelling on the left side of the head over the last year is reported. The lump was 15 x 15 cm and protruded 1-3 centimeters. Neurological examination revealed the presence of a mild right hemiparesis with right central facial palsy. Plain skull X-ray film demonstrates a heterogeneous bone thickening in the left fronto-temporo-parietal region with a small osteolytic focus and spotted shadows. Computed tomography scan of the skull showed that a major part of the squamas of the frontal and temporal bones were transformed into spiculoform structures turned outwards and inwards. Thus the bone appeared thickened overall. There were no alterations in the cerebral structures. The tumour was completely removed. It was located extradurally and through the bones extended to the soft tissues under the skin. The histological findings showed a meningioma with hemorrhages and necroses and the presence of lipids containing xanthochromic cells. After a surgical extirpation of the tumour a reduction of the neurological symptomatology and subjective complaints was observed.

Bone induction using autogenous bone mixed with demineralised bone matrices

The aim of the present study was to examine the healing of endochondral (EC) autogenous bone grafts in the presence of demineralised bone matrix prepared from intramembranous bone (DBMIM), or prepared from endochondral bone (DBMEC) using quantitative analysis. Thirty bone defects were created on the parietal bone of fifteen New Zealand White rabbits. In the experimental groups, five defects were grafted with EC bone, five defects were grafted with EC bone mixed with DBMIM (EC-DBMIM) and six defects were grafted with EC bone mixed with DBMEC (EC-DBMEC). In the control groups, ten defects were left empty (passive control) and four defects were grafted with rabbit skin collagen (positive control). They were all sacrificed at day fourteen post grafting, and the defects were prepared for histological analysis. Serial sections were cut across the whole defect. Quantitative analysis was performed on 152 sections of the experimental groups by image analysis. Four hundred and fourteen per cent more new bone was formed in defects grafted with composite EC-DBMIM than those grafted with EC bone alone (p < 0.001). Eighty-five per cent more new bone was formed in defects grafted with composite EC-DBMEC than those grafted with EC bone alone (p < 0.001). No bone was formed in either passive or positive controls. In conclusion, DBM, especially DBMIM, have extremely high osteoinductive properties and greatly enhance the integration of EC bone grafts with defects created in IM bone.

Tuberculous osteitis of the cranium: a case report

A 3-year old male presented with a 12-month history of painless scalp swellings associated with cough, fever and night sweats. Physical examination showed tender, fluctuant, pulsatile right frontotemporal and temporoparietal masses. Skull radiographs showed osteolytic skull lesions in the frontal and temporal bones. Microscopy of drained caseous material and histology of biopsies from the affected bone edges confirmed tuberculous osteitis. Though there was an initial response to antituberculous agents, the child died after 5 weeks from hepatic failure. Tuberculosis of the skull bones though rare, may become more common with the recent upsurge of tuberculosis worldwide. A high index of suspicion is necessary for early diagnosis and treatment.

Bone augmentation by recombinant human BMP-2 and collagen on adult rat parietal bone

A composite of recombinant human bone morphogenetic protein-2 (rhBMP-2) and collagen was implanted beneath the cranial periosteum of 10-month-old rats to observe bone development and absorbent change of carrier collagen. The rhBMP-2/collagen onlay implant resulted in active bone formation and the augmented bone was connected directly with the original bone, whereas the collagen alone resulted in neither bone nor cartilage. The ossification process in the rhBMP-2/collagen occurred directly through bone formation, similar to intramembranous ossification. The carrier collagen fibers were found in the woven bone and were completely absorbed at 8 weeks in the presence of rhBMP-2, while the collagen alone implant remained encapsulated by a thin, fibrous connective tissue. Our results indicate that rhBMP-2/collagen is an effective material as a biological onlay implant, showing osteoinductive properties and being completely replaced by new bone. Carrier collagen not only plays a role in rhBMP-2 delivery, but also provides a cell anchorage for cell differentiation and remains as an artificial matrix in woven bone.

Giant cavernous hemangioma of the scalp

In this article, a quite rare giant cavernous hemangioma located in right frontoparietal region of a 16 year-old boy is presented. Cavernous hemangiomas are commonly seen in extremities, neck, face and sometimes scalp, cutaneous or subcutaneous in localization. Giant cavernous hemangioma in the right frontoparietal region have been seen in two cases so far. In this article, we discussed the differential diagnosis, characteristics and therapy methods of giant cavernous hemangioma of the scalp.

Intracranial osteosarcomas: report of four cases and review of the literature

Four cases of intracranial osteosarcoma are reported. In three cases the tumors were primary neoplasms arising from the sellar region, base of the occiput and the parieto-occipital area. One case represented osteosarcoma metastatic to the cerebellum, a site not previously described, from a primary tumor at the femur. In addition, the current literature on intracranial osteosarcoma is reviewed.

Bilambdoid and posterior sagittal synostosis: the Mercedes Benz syndrome

A consistent pattern of craniosynostosis in the sagittal and bilateral lambdoid sutures is described in three patients. The external cranial ridging associated with fusion of these sutures produces a characteristic triradiate, or "Mercedes Benz," appearance to the posterior skull. Locally marked growth restriction is evident in the posterior fossa with compensatory secondary expansion of the anterior fossa manifesting a degree of frontal bossing which mimics bicoronal synostosis. Although this appearance could lead to inadvertent surgery in the frontal region, attention to the occipital region with wide early suture excision and vault shaping is indicated.

Regional variations in the progression of bone loss in two different mouse osteopenia models

Differences in trabecular and cortical bone loss have been demonstrated clinically, but differences in bone loss at different skeletal sites remain unclear. We examined regional variations in bone loss histomorphometrically in two strains of mice in which osteopenia progresses spontaneously: tiptoe-walking Yoshimura (twy) mice (from 4 to 37 weeks of age) and senescent ICR mice (from 4 to 88 weeks of age). Morphometrical measurements were obtained to investigate the changes with age in trabecular bone area and anterior cortical bone width in the lumbar vertebral body, trabecular bone area in the tibia, bone area in the parietal bone, and the cortical index in the humerus. Results showed that, in twy mice, trabecular turnover was higher than in ICR mice, and bone loss progressed in the following order: tibial trabecular bone, lumbar trabecular bone, parietal bone, lumbar anterior cortical bone, and the humerus. In ICR mice, bone formation declined after 60 weeks. Bone loss progressed in tibial trabecular bone and the parietal bone at 60 weeks of age, followed by lumbar trabecular bone, lumbar anterior cortical bone, and the humerus at 88 weeks of age. Bone loss varied at each site and between the two mouse strains, with different bone turnover rates. The findings of the present study indicate that special attention should be paid to regional variations in the progression of bone loss associated with differences in pathologic features.

Familial osteoma of the cranial vault

A case of solitary osteoma of the parietal skull is described in a mother and her 12-year-old son. There were no other craniofacial or dysmorphic features and there was no history of previous cranial trauma or inflammatory process and no radiographic evidence of other skeletal lesions in both patients. Family history was otherwise unremarkable. Gardner syndrome was ruled out by excluding other associated clinical abnormalities and by family history. The clinical and radiological features of the patients' osteomas were different from those of Albright hereditary osteodystrophy, fibrodysplasia ossificans progressiva, progressive osseous heteroplasia and familial ectopic ossification. To the author's knowledge this is the first case of the familial presentation of osteomas.

Arterialized occipitoparietal osteocutaneous flap

We treated a case of postoperative osteomyelitis and epidural abscess in the left temporal and parietal region. The scalp and skull defect following debridement was reconstructed immediately with an arterialized occipitoparietal osteocutaneous flap that was supplied proximally by the occipital artery and distally by the superficial temporal artery. This method is one of the alternative methods for small to moderately sized skull and scalp defects in the temporal, parietal, and occipital areas without available superficial temporal artery.

Intracranial chondroma arising from the cranial vault: CT and MR appearance

A case of intracranial chondroma arising from the right parietal bone in a 37-year-old woman is presented. CT and MRI findings as well as the differential diagnosis of the lesion are discussed.

The auriculomastoid fasciocutaneous island flap: a new flap for orofacial reconstruction

PURPOSE

Various designs for previously reported postauricular skin flaps have the disadvantages of being two-stage procedures, providing a limited pedicle, or requiring microvascular anastomoses. To overcome such problems, a new auriculomastoid fasciocutaneous (AMFC) island flap for orofacial reconstruction has been developed. This article presents the technique and reports the clinical results.

PATIENTS AND METHODS

A long ipsilateral AMFC island flap pedicled by the parietotemporal fascia and based on the parietal branches of the superficial temporal artery, the occipital artery, and the postauricular artery was designed. Twenty-five of these island flaps were used to reconstruct intraoral or external facial defects.

RESULTS

The fasciocutaneous flap could be extended to reach any orofacial defect as a single or compound design in a one-stage subcutaneous procedure. Compound types of AMFC island flaps, including scalp, parietal bone, or the parietotemporal fascia were performed successfully based on single vessels. The flap has the characteristics of providing thin and pliable skin, a good color match to the face, and restored sensitivity. The donor defect is designed to be closed directly and concealed behind the ear without ear deformity.

CONCLUSIONS

This flap is very useful in orofacial reconstruction because the skin quality equals that of the radial forearm flap, without the need for microvascular anastomoses, with many additional advantages and various modifications of design.

Respiratory mechanics in the open chest: effects of parietal pleurae

To understand how the parietal pleurae affect the mechanical behavior of the human respiratory system after the chest wall is opened by median sternotomy, we studied 18 anesthetized/paralyzed patients immediately before coronary artery bypass grafting surgery. Elastances and resistances of the total respiratory system (ETr, Rrs) were calculated from measurements of airway pressure and flow during mechanical ventilation in the frequency and tidal volume ranges of normal breathing. Elastances and resistances of the lungs (EL, RL), chest wall (Ecw, Rcw) were also estimated from measurements of esophageal pressure. Data were collected in the closed chest, after median sternotomy with the parietal pleurae intact and after the left parietal pleura was opened for internal mammary artery harvest. After sternotomy with pleurae intact (n = 14), Ers did not change but Rrs decreased (p < 0.05). Ecw (including the contribution of the pleurae) was higher than in the closed chest (p < 0.05) while EL and RL were lower (p < 0.05); Rcw did not change. Opening the left pleura (n = 10) decreased Ers (p < 0.05), but Rrs did not change. We conclude that the chest wall/pleurae compartment offers significant impedance to lung expansion after sternotomy and rib retraction, unless one pleura is opened.

Use of a fibrillar polylactic acid homopolymer in sheep cranial defects

Guided tissue regeneration has been shown to permit osteoconduction in otherwise nonhealing cranial defects. The relative importance of preventing the prolapse of soft tissue versus the infiltration of individual connective tissue cells has not been determined. A fibrillar form of polylactic acid (PLA) was tested in 13-mm-diameter defects in the parietal bones of 12 sheep. The polymer was hypothesized to prevent the prolapse of dura and periosteum but allow entrance of individual cells. Control defects in the same sheep were either filled with autogenous bone shavings or left unfilled. The animals were killed at times ranging from 6 to 25 weeks and the defects examined grossly, radiologically, and histologically. The autogenous bone-filled defects were spanned by trabeculated bone by 6 weeks. The unfilled defects demonstrated prolapse of soft tissues into the defect; however, progressive centripetal bone growth was evident. The fibrillar PLA-filled defects were occupied by a full-thickness mixture of fibrous tissue interspersed with PLA. After 19 weeks, small "fingers" of bone were seen to minimally infiltrate the fibrous tissue. Although separation of the dura and periosteum was maintained by the fibrillar PLA, invasion of fibrous tissue restricted osteoconduction.

Unusual lytic intraosseous meningioma

Lytic intraosseous meningiomas are rare. This unusual case presented a diagnostic and treatment challenge.