Comparative microcomputed tomography and histological study of maxillary pneumatization in four species of new world monkeys: the perinatal period.

In anthropoid primates, it has been hypothesized that the magnitude of maxillary sinus growth is influenced by adjacent dental and soft tissue matrices. Relatively, little comparative evidence exists for the perinatal period when secondary pneumatization is at its earliest stages in some primates. Here, dental and midfacial variables were studied in a perinatal sample of four anthropoid primates, including three callitrichines (Leontopithecus, Saguinus, and Callithrix) and Saimiri boliviensis. In the latter species, the maxillary recess (the ontogenetic precursor to a "true" maxillary sinus) does not undergo secondary pneumatization. Using histological methods and micro-computed tomography, midfacial and dental dimensions and radiographic hydroxyapatite density of tooth cusps were measured. The distribution of osteoclasts and osteoblasts was also documented. Kruskal-Wallis's one-way analysis of variance tests indicates significant (P < 0.05) differences among groups for dental and midfacial measurements. In particular, the posterior maxillary dentition is relatively larger and more mineralized in Saimiri compared to the callitrichines. At posterior dental levels, Saimiri has the lowest palatonasal index [interdental (palatal) width/width of the nasal cavity] and highest bizygomatic-interorbital index. Distribution of osteoclasts indicates that the inferomedial surfaces of the orbits are resorptive in perinatal Saimiri, whereas, in all callitrichines, these surfaces are depository. Taken together, these findings suggest that pneumatization in Saimiri is suppressed by an inward growth trajectory of the orbits, relatively large posterior dentition, and a correspondingly compressed nasal region.

In vitro regulation of proliferation and differentiation within a postnatal growth plate of the cranial base by parathyroid hormone-related peptide (PTHrP).

Parathyroid hormone-related peptide (PTHrP) is known to be an important regulator of chondrocyte differentiation in embryonic growth plates, but little is known of its role in postnatal growth plates. The present study explores the role of PTHrP in regulating postnatal chondrocyte differentiation using a novel in vitro organ culture model based on the ethmoidal growth plate of the cranial base taken from the postnatal day 10 mouse. In vitro the ethmoidal growth plate continued to mineralize and the chondrocytes progressed to hypertrophy, as observed in vivo, but the proliferative zone was not maintained. Treatment with PTHrP inhibited mineralization and reduced alkaline phosphatase (ALP) activity in the hypertrophic zone in the ethmoidal growth plates grown ex vivo, and also increased the proliferation of non-hypertrophic chondrocytes. In addition, exogenous PTHrP reduced the expression of genes associated with terminal differentiation: type X collagen, Runx2, and ALP, as well as the PTH/PTHrP receptor (PPR). Activation of the protein kinase A pathway using 8-Br-cAMP mimicked some of these pro-proliferative/anti-differentiative effects of PTHrP. PTHrP and PPR were found to be expressed within the ethmoidal growth plate using semi-quantitative PCR, and in other cranial growth plates such as the spheno-occipital and pre-sphenoidal synchondroses. These results provide the first functional evidence that PTHrP regulates proliferation and differentiation within the postnatal, cranial growth plate. J. Cell. Physiol. 219: 688-697, 2009. (c) 2009 Wiley-Liss, Inc.

Rabbit olfactory stem cells. Isolation protocol and characterization.

PURPOSE: To describe a new technique for isolation of a mesenchymal stem cells (MSCs) population from the olfactory mucosa in rabbits. METHODS: Olfactory stem cells (OSCs) were retrieved from under the cribriform plate of the Ethmoid bone. Several assays were accomplished to characterize the cell population and attest its viability in vitro. The cells were submitted to flow cytometry with the antibodies CD34, CD45, CD73, CD79, CD90 and CD105 and also they were induced to differentiate in three lineages. Functional evaluation involved analysis of in vitro growth behavior, colony forming unit like fibroblasts (CFU-f) and cryopreservation response. Further transduction with Green Fluorescent Protein (GFP) was also performed. RESULTS: The OSCs showed mesenchymal features, as positive response to CD34, CD73 and CD90 antibodies and plasticity. Additionally, these cells have high proliferated rate, and they could be cultured through many passages and kept the ability to proliferate and differentiate after cryopreservation. The positive response to the transduction signalizes the possibility of cellular tracking in vivo. This is a desirable feature in case those cells are used for pre-clinical trials. CONCLUSION: The cells harvested were mesenchymal stem cells and the technique described is therefore efficient for rabbit olfactory stem cells isolation.

Ethmoid roof radiology; analysis of lateral lamella of cribriform plate.

OBJECTIVE: We evaluated the extent of asymmetry evident in paranasal sinus computed tomography (CT) scans of Turkish patients without sinusitis in the ethmoid roof. Our data contribute to the body of knowledge on the subject. MATERIALS AND METHODS: We retrospectively studied multiplanar reformatted CT images of the paranasal sinus (1-mm sections) from 110 patients (50 male, 60 female). Ethmoid roof variations on either side were compared and the lateral lamellar length of the cribriform plate was measured. The results were scored using the Keros classification. RESULTS: The lateral lamella of the cribriform plate averaged 5.78 mm in height on the right side and 5.98 mm on the left. The most common Keros type was type 2 (67.72%), followed by type 3 (22.28%), and type 1 (10%). Keros asymmetry (≥ 0.01 mm, affecting either side) was apparent in all patients (48.2% right-sided and 51.8% left-sided). RESULTS: Preoperatively, paranasal sinus CT scans should be evaluated carefully to eliminate the possibility of life-threatening complications, including intracranial trauma, which may develop during endoscopic sinus surgery; the left and right sides of the ethmoid roof may differ in depth.

Relation of the ethmoidal cells to the floor of the anterior cranial fossa.

The shape of the anterior part of the anterior cranial fossa undergoes important changes in the postnatal life depending on the degree of pneumatisation of the ethmoid labyrinth and/or the frontal sinus. There exist three possibilities in these relations: 1) From the newborn period up to 9 years of age, in the majority of the cases the cribrous plate is situated at the level of the roof of the ethmoid labyrinth with the width of the ethmoid incisure corresponding to the width of the cribrous plate. 2) In the period from 9-35 years of age, in the majority of cases, the ethmoidal cells are partly or completely incorporated into the floor of the anterior cranial fossa with the width of the ethmoid incisure corresponding to the number of cells forming the floor of the anterior cranial fossa. 3) In the period from 35-80 years of age, the cribrous lamina is in the majority of cases lowered due to the intensive development of the frontal sinus. The medial wall of the ethmoid labyrinth consists of a thin bony strip, the width of which depends upon the degree of lowering of the cribrous plate. Adequate CT imaging may clarify the situation.

The ethmoid labyrinth: an anatomical and comparative radiological study.

After an osteologic description of the ethmoid labyrinth, the radiologic techniques which best display the ethmoidal cell topography, relationships and configuration are examined. On the basis of these observations it is concluded that standard radiographic tests cannot give a clear anatomic-radiologic representation of the ethmoid cells and that they must be supplemented with tomography.

Establishment of osteoblast culture from human ethmoidal sinus.

OBJECTIVE: Chronic sinusitis is characterized by persistent chronic inflammation of the sinus system and local expression and release of various cytokines, such as IL-1 beta, IL-4, IL-6, IL-8, TGF-beta and TNF-alpha are deeply involved in the pathogenesis of the disease. We hypothesized that not only the sinus mucosa-containing cells, such as epithelial cells and fibroblasts, but also osteoblasts, of which sinus bone structure consists, may contribute to this inflammatory network. This study evaluates the development and establishment of an osteoblasts culture system derived from human ethmoidal sinus as an initial step toward verifying this hypothesis. METHODS: Ethmoidal sinus bone was obtained from patients at the time of sinus surgery for chronic sinusitis and outgrowth cell sheets were obtained according to the explant-outgrowth cell culture technique. In order to examine the specific characteristics of osteoblasts in the obtained cells, four major features of osteoblasts (collagen type I, osteocalcin synthesis, alkaline phosphatase activity and extracellular matrix mineralization ability) were investigated at the third passage of the culture and productions of TGF-beta 1, which modulate osteoblast proliferation and maturation in an autocrine fashion, in the cultured medium was also investigated in time of culture up to 20 days. RESULTS: The cells obtained in our study clearly show collagen type I synthesis, osteocalcin synthesis, alkaline phosphatase activity and production of visible extracellular matrix mineralization. Production of TGF-beta 1 in the medium did not significantly different in time of culture up to 20 days. CONCLUSION: Our results, the first of their kind, indicate that osteoblast-like cells can be cultured from adult human ethmoidal sinus bones. It suggested that proliferation and maturation of the osteoblast were continuously modulated in an autocrine fashion by producing TGF-beta 1.

[Anatomic and endoscopic studies of the anterior ethmoid]. / Etude anatomique et endoscopique de l'ethmoïde antérieur.

Introduction of present-day sinonasal endoscopy and progress in endonasal surgery under endoscopic guidance of endoscopy provide for anatomical exploration of the anterior part of the ethmoid bone, which is the crosspoint of the facial sinus draining paths. We propose to present here a simple and logical scheme of the topographical anatomy of the ethmoid bone. Classification of the ethmoidal cells allows to define the structures, whereby appropriate nomenclature may be adopted and certain confusions avoided. Thus, each cell within particular cell groups acquires a specific designation based on its draining paths and location in relation to basal lamellae. Endoscopic analysis also deserves being described in some length, since the panoramic view afforded by currently used optics modifies the image ans requires that the observer develop an "endoscopic eye". We draw attention to the endoscopic anatomical fine points in the crucial area of the bullar "circus". These landmarks come in as necessary guides in surgical practice.

Rabbit olfactory stem cells. Isolation protocol and characterization

PURPOSE: To describe a new technique for isolation of a mesenchymal stem cells (MSCs) population from the olfactory mucosa in rabbits. METHODS: Olfactory stem cells (OSCs) were retrieved from under the cribriform plate of the Ethmoid bone. Several assays were accomplished to characterize the cell population and attest its viability in vitro. The cells were submitted to flow cytometry with the antibodies CD34, CD45, CD73, CD79, CD90 and CD105 and also they were induced to differentiate in three lineages. Functional evaluation involved analysis of in vitro growth behavior, colony forming unit like fibroblasts (CFU-f) and cryopreservation response. Further transduction with Green Fluorescent Protein (GFP) was also performed. RESULTS: The OSCs showed mesenchymal features, as positive response to CD34, CD73 and CD90 antibodies and plasticity. Additionally, these cells have high proliferated rate, and they could be cultured through many passages and kept the ability to proliferate and differentiate after cryopreservation. The positive response to the transduction signalizes the possibility of cellular tracking in vivo. This is a desirable feature in case those cells are used for pre-clinical trials. CONCLUSION: The cells harvested were mesenchymal stem cells and the technique described is therefore efficient for rabbit olfactory stem cells isolation.

Sphenoid sinus: an anatomic and endoscopic study in Asian cadavers.

An anatomic and endoscopic study of 48 cadaveric heads (96 sphenoid sinuses) was undertaken to describe the anatomy of the sphenoid sinus in Asians. Sellar type of sphenoid sinus is the most common, present in 53 out of 96 sides (55%). Forty-five of the 48 heads had a dominant sphenoid cavity, of which 11 contained vital structures from both sides of the sphenoid sinus. The incidence of accessory septae, carotid artery, optic nerve, maxillary nerve, and vidian nerve bulges were 70.8%, 67.7%, 69.8%, 61.5%, and 64.6%, respectively. There is a significantly higher number of overriding ethmoid sinuses in Asian cadavers (46/96 sides) compared to western studies (P < 0.0005). Seven (15%) of these 46 sides were also Onodi positive. The rest of the overriding ethmoid cells were Onodi negative. Surgeons should be aware of the significantly higher number of overriding posterior ethmoid cells in Asian populations during functional endoscopic sinus surgery (FESS). The optic nerve is at risk during FESS surgery if the sphenoid sinus is sought behind the deepest point of these posterior ethmoid cells. These overriding posterior ethmoid cells may also confuse the unwary surgeon that he has entered the sphenoid sinus where in fact he is still operating in the posterior ethmoid cells.

The bulla ethmoidalis: lamella or a true cell?

BACKGROUND: The anterior ethmoidal region, including the bulla ethmoidalis, is the most common area addressed during functional endoscopic sinus surgery. Therefore, a detailed understanding of the bulla is essential for safe and effective surgery. HYPOTHESIS: Based on a review of historical articles on sinus anatomy and review of the current understanding of sinonasal embryology, it is suggested that the ethmoidal bulla is a "lamella" structure rather than a "cell," as it is widely accepted to be. OBJECTIVE: To analyze the anatomic conformation and nature of the ethmoidal bulla. METHODS: Detailed gross anatomic sagittal dissection of 14 sinonasal complexes with special attention to the ethmoidal bulla and surrounding structures and pneumatization tracts. RESULTS: The ethmoidal bulla consisted of a distinct bony lamella in all cases. The degree of development and pneumatization was variable, ranging from a rudimentary torus to a relatively well-pneumatized "bulla"-like structure. A pneumatization tract originating from the retrobullar recess was present in all specimens. This pneumatization excavated into the lamella, creating the bulla-like appearance as viewed from the middle meatus. However, the bulla was not a discrete individual ethmoid cell as it did not have a complete or discrete posterior bony wall. Rather, the posterior wall of this pneumatization tract was formed by the basal lamella. CONCLUSION: The ethmoidal bulla lacks a distinct posterior wall and therefore is not a separate cell but rather a bony lamella with an air space behind it. From an anatomic perspective, bulla is perhaps not the best term for this structure.

A comparative radioautographic study of chondrocytic proliferation in nasal septal cartilage of the 5-day-old rat, rabbit, guinea pig and beagle.

Growth sites within the cartilaginous nasal septa of four different species of animals (5-day-old rats, rabbits, guinea pigs and beagles) were identified by monitoring cellular proliferation radioautographically. A statistical analysis (MANOVA) was employed. It showed that, of the six combinations compared (rat-beagle, rat-guinea pig, rat-rabbit, beagle-guinea pig, beagle-rabbit, and guinea pig-rabbit), in only one (beagle-guinea pig) was there any similarity in growth pattern. The other five combinations all were significantly different. Since no particular areas emerged, with any consistency, as common growth sites within any of the four kinds of septa, it was concluded that the nasal septum might well play a passive role in midfacial growth, rather than an active role as previously thought.

Bone-constructing cells from ethmoid bone may have multilineage differentiation potential: preliminary report.

OBJECTIVE: In order to investigate multilineage differentiation in human cultured cells from ethmoid bone, we conducted a morphological study to examine adipogenic and chondrogenic differentiation. MATERIAL AND METHODS: After reaching confluence, cells underwent terminal adipogenic differentiation by treatment with 100 microM indomethacin, 0.5 mM 1-methyl-3-isobutylxanthine, 1 microM dexamethasone (DEX), 10 microg/ml insulin and 0.3% dimethylsulfoxide in a medium supplemented with 10% fetal bovine serum. Chondrogenic differentiation was attempted by centrifuging a pelleted micromass using transforming growth factor-beta3 (TGF-beta3), DEX, ascorbic acid (AA), pyruvate acid, proline, glucose and (ITS)-plus. RESULTS: The cultured cells displayed adipocyte but not chondrogenic lineage under these conditions. Considering the possibility that some differentiation potential may be lost with in vitro culture but maintained using another chondrogenic differentiation medium containing TGF-beta1, it is possible that cultured cells may have multilineage potential, including chondrogenic differentiation ability. CONCLUSIONS: These morphological abilities of human cultured cells may indicate the possibility of the existence of mesenchymal stem cells in sinus bone. If mesenchymal stem cells exist in ethmoid bone, they may play an important role in future research on the regulation mechanisms of human bone tissue.

Experimental study of the frontal sinus development on Goettingen miniature pigs.

According to the literature, the development of the frontal sinus cavity is a result of the active immigration of cells from the ethmoidal complex into the os frontale. This migration theory is in contrast to the operative outcome of Apert's syndrome patients, after fronto-orbital advancement. When a fronto-orbital advancement at the age of a few months is performed in these patients while the frontal suture is yet closed, a sinus developed even the distance between nasal root and frontal bone bing up to 2 cm. In order to study the development of the frontal sinus, an animal study on 12 five-week-old infant Goettingen minipigs (GMP) was conducted, which did not have any clinical or histological signs of a frontal sinus development to investigate the development of the frontal sinus in "orthotopically" transplanted frontal bone with an open frontal suture. A comparison was made to a control group. The macro- and microscopical comparison with a control group revealed that the orthotopical transplants in the occipital bone developed epithelium-lined sinus, beginning from the thirty-fifth week. Based on these histomorphological results, a development scheme for the genesis of the sinus frontalis as a model were drawn.