The presence of bacterial microcolonies on the maxillary sinus ciliary epithelium in healthy young individuals.

OBJECTIVE: The aim of this cross-sectional in vitro study was to evaluate the mucosal surfaces of healthy maxillary sinuses, explore different forms of bacterial microorganism colonies present on the mucous membrane, and determine a mucosal surface area they occupy. METHODS: Samples of the maxillary sinus mucosa were collected from 30 healthy patients (M = 11; F = 19). The material was obtained during the Le Fort I osteotomy performed during corrective jaw surgery. The morphological and morphometric analysis of sinus mucosa and bacterial film that was grown on it was performed using scanning electron microscopy (SEM) as well as imaging software. RESULTS: Scanning electron microscopy analysis showed the presence of different bacterium and bacteria-like structures in all the analyzed samples. In most cases, the bacterial film was mostly composed of diplococci-like and streptococci-like structures on the mucosa of the paranasal sinus. In any case, the mucous layer did not cover the whole lining of the evaluated sample. Each colony consists of more than 20 single bacterial cells, which has grown in aggregates. CONCLUSIONS: Under the conditions of normal homeostasis of the body, the maxillary sinuses present diverse bacterial colonization. The bacteria are dispersed or concentrated in single microcolonies of the biofilm on the border of the mucous covering the ciliary epithelium. There is no uniform layer of the biofilm covering the mucosa of the maxillary sinuses. Because the biofilm is detected on healthy individuals sinus mucosa, the clinical question if it may become pathogenic is unclear and require an explanation.

FGF and EDA pathways control initiation and branching of distinct subsets of developing nasal glands.

Hypertrophy, hyperplasia and altered mucus secretion from the respiratory submucosal glands (SMG) are characteristics of airway diseases such as cystic fibrosis, asthma and chronic bronchitis. More commonly, hyper-secretion of the nasal SMGs contributes to allergic rhinitis and upper airway infection. Considering the role of these glands in disease states, there is a significant dearth in understanding the molecular signals that regulate SMG development and patterning. Due to the imperative role of FGF signalling during the development of other branched structures, we investigated the role of Fgf10 during initiation and branching morphogenesis of murine nasal SMGs. Fgf10 is expressed in the mesenchyme around developing SMGs while expression of its receptor Fgfr2 is seen within glandular epithelial cells. In the Fgf10 null embryo, Steno's gland and the maxillary sinus gland were completely absent while other neighbouring nasal glands showed normal duct elongation but defective branching. Interestingly, the medial nasal glands were present in Fgf10 homozygotes but missing in Fgfr2b mutants, with expression of Fgf7 specifically expressed around these developing glands, indicating that Fgf7 might compensate for loss of Fgf10 in this group of glands. Intriguingly the lateral nasal glands were only mildly affected by loss of FGF signalling, while these glands were missing in Eda mutant mice, where the Steno's and maxillary sinus gland developed as normal. This analysis reveals that regulation of nasal gland development is complex with different subsets of glands being regulated by different signalling pathways. This analysis helps shed light on the nasal gland defects observed in patients with hypohidrotic ectodermal dysplasia (HED) (defect EDA pathway) and LADD syndrome (defect FGFR2b pathway).

[The staphylococcal enterotoxin burden determines the ultrastructure of ciliated epithelia and inflammatory changes in maxillary sinus mucosa of rabbits].

OBJECTIVE: To investigate the ultrastructure of ciliated epithelia and inflammatory changes upon repeated exposure to staphylococcal enterotoxin A (SEA) of different concentrations in the maxillary sinus mucosa of rabbits. METHODS: The rabbits were randomly divided into 2 groups (24 rabbits per group): low-dose SEA group and high-dose SEA group. The low-dose SEA group and high-dose SEA group received daily injections of 0.6 ng of SEA (2 ml) and 60 ng of SEA (2 ml) into the left maxillary sinus of rabbits for 28 days, respectively. Concurrent treatment of the right maxillary sinus with normal saline was used as control. Six rabbits chosen randomly in two groups were examined by computed tomography (CT) scans and then sacrificed to obtain the sinus mucosa from the two-side of maxillary sinuses for histological assessment on days 3, 7, 14 and 28. To characterize the inflammatory changes of the sinus mucosa examined using light microscope, hematoxylin and eosin (HE) and toluidine blue staining was performed. Scanning and transmission electron microscopy were performed to observe ultrastructure of ciliated epithelia in the maxillary sinus mucosa. SPSS 13.0 software was used to analyze the data. RESULTS: On days 14 and 28, CT images showed opacification of the left maxillary sinus in the high-dose SEA group. The percentage of epithelial disruption was (22.73 ± 5.72) % and (30.79 ± 4.30)% in the high-dose SEA group respectively, and were significantly greater than those in the low-dose SEA group (5.12% ± 1.98% and 5.38% ± 1.64%, q value was 10.079 and 19.132) and control group (4.08% ± 1.29% and 4.81% ± 1.62%, q value was 11.016 and 19.592, respectively, all P < 0.01). The subepithelial thickness in the high-dose SEA group was (113.34 ± 14.81)µm and (120.86 ± 12.35) µm respectively, and were significantly different from those of the low-dose SEA group [(71.08 ± 10.39)µm and (81.63 ± 9.32)µm, q value was 8.090 and 8.782] and control group [(37.45 ± 7.67)µm and (38.79 ± 7.68)µm, q value was 15.759 and 19.541, all P < 0.01]. Viewed under the electron microscope, loss of cilia was observed, a few compound cilia and cytoplasmic protrusion were found, an obvious stretching of the endoplasmic reticulum and an obvious turgescence of the mitochondria was also observed. However, in the low-dose SEA group on days 14 and 28, CT scan of the left maxillary sinus showed transparency; light microscopy observations of the maxillary sinus mucosa showed the number of eosinophils was markedly increased as compared with the high-dose SEA and control groups, the differences were significant (q value was 5.871 and 6.766 on day 14, and q value was 7.572 and 8.970 on day 28, respectively, all P < 0.05). But no significant differences were observed in epithelial disruption between the low-dose SEA and the control groups on days 14 and 28 (q value was 1.512 and 0.859 respectively, all P > 0.05); inordinate array and adhesion of cilia was observed, but cilia loss, compound cilia, cytoplasmic protrusions, mitochondrial swelling and endoplasmic reticulum stretching were not found. CONCLUSIONS: SEA may induce allergic inflammation of the sinus mucosa without damaging the structure of ciliated epithelia at low concentration. Whereas SEA impairs the structure of mitochondria and endoplasmic reticulum in ciliated epithelial cells at high concentration, and results in cilia loss and epithelial disruption, which may be one of the main reasons to induce acute sinusitis.

Ultrastructural study by backscattered electron imaging and elemental microanalysis of bone-to-biomaterial interface and mineral degradation of porcine xenografts used in maxillary sinus floor elevation.

OBJECTIVES: The aim of this study was to carry out an ultrastructural study of the biomaterial-to-bone interface and biomaterial mineral degradation in retrieved bone biopsies following maxillary sinus augmentation using collagenized porcine xenografts (Osteobiol(®) Mp3) in 15 clinical cases. MATERIALS AND METHODS: Nine months after sinus lifting, bone cores were harvested from the maxillary sinus. The specimens were processed for observation under a scanning electron microscope with backscattered electron imaging (SEM-BSE). In addition, chemical analysis and elemental mapping of the mineral composition were generated using a microanalytical system based on energy-dispersive X-ray spectrometry (EDX). RESULTS: No clinical complications were evident during surgery. Scanning electron microscopy revealed that newly formed bone had become closely attached to the xenograft. Statistical analysis showed a significantly high Ca/P ratio in the biomaterial (2.46 ± 0.16) and at the bone interface (2.00 ± 0.48) compared to bone (1.97 ± 0.36), which suggests that there may be a gradual diffusion of Ca ions from the biomaterial into the newly forming bone at the interface as part of the biomaterial's resorption process. EDX analysis of the residual porcine biomaterial at different points showed some particle categories with different mean ratios of Ca/P according to size, pointing to different stages of the resorption process. CONCLUSIONS: The biomaterial proved to be biocompatible, bioreabsorbable and osteoconductive when used as a bone substitute for maxillary sinus elevation. SEM-BSE revealed that newly formed bone had become closely attached to the xenografts. EDX analysis monitored the resorption process of the porcine bone xenograft. Elemental mapping showed that there was a gradual diffusion of Ca ions from the biomaterial to the newly forming bone at the interface.

Ultrastructural study by backscattered electron imaging and elemental microanalysis of biomaterial-to-bone interface and mineral degradation of bovine xenografts in maxillary sinus floor elevation.

OBJECTIVES: The aim of this study was to perform an ultrastructural study of the bone-to-biomaterial interface and biomaterial mineral degradation in retrieved bone biopsies following maxillary sinus augmentation using bovine xenografts (Endobon(®)) in 15 clinical cases. MATERIALS AND METHODS: Nine months after sinus lifting, bone cores were harvested from the maxillary sinus. The specimens were processed for observation under a scanning electron microscope with backscattered electron imaging (SEM-BSE). In addition, chemical analysis and elemental mapping of the mineral composition were generated using a microanalytical system based on energy-dispersive X-ray spectrometry (EDX). RESULTS: No clinical complications occurred during surgery. Scanning electron microscopy revealed that newly formed bone was closely attached to the xenograft. Elemental analysis showed a significantly high Ca/P ratio in the residual biomaterials (3.031 ± 0.104) compared with the interface (2.908 ± 0.115) and new bone (2.889 ± 0.113), which suggests that there may be a gradual diffusion of Ca ions from the biomaterial into the newly forming bone at the interface as part of the biomaterial's resorption process. EDX analysis of the residual bovine biomaterial showed particle categories with different mean Ca/P ratios according to size, pointing to different stages of the resorption process. CONCLUSIONS: The biomaterial proved to be biocompatible and osteoconductive when used as a bone substitute for maxillary sinus elevation. The grafting material used is not a completely resorbable material over the time period covered by this study.

[Observation on ultrastructure of maxillary sinus mucosa in experimental acute sinusitis].

OBJECTIVE: To observe ultrastructure of maxillary sinus mucosa of experimental acute sinusitis in rabbits. METHOD: Twenty-five rabbits were randomly divided into experimental group (20 rabbits) and blank control group (5 rabbits). We established a rhinogenic model of experimental acute sinusitis in experimental group. Five rabbits chosen randomly in experimental group were sacrificed and dissected after 1, 2, 3, and 4 weeks, and the tissue (0.3 cm x 0.3 cm) of sinus mucosa were prepared for visualization by transmission electron microscope (TEM). Animals in blank control group were sacrificed after 1 week. RESULT: Under the transmission electron microscope, in the blank control group, cilia of maxillary sinus mucosa lined up in order without ciliary loss, no stretched endoplasmic reticulum or turgescent mitochondria was observed. However, in the experimental group, inordinate array and loss of cilia was observed, a few compound cilia and cytoplasmic protrusion were also found. Both endoplasmic reticulum and mitochondria were swelling, and the lymphocytes were infiltrating with fibroblast proliferation in the submucosa. There was statistically significant difference between the experimental group and the blank control group (P < 0.05). In the experimental group, the number of compound cilia increased from 1 to 4 weeks, and the amount of compound cilia of the mucosa at 3 and 4 weeks was significantly higher than that at 1 week (P < 0.05). Swelling of mitochondria and endoplasmic reticulum was severe at 2 weeks and abated gradually with time, the results at 2 weeks were different from those of experimental group at 4 weeks (P < 0.05). CONCLUSION: The obstruction of nasal sinuses and the bacterial infection might lead to ultrastructural changes of maxillary sinus mucosa, and these ultrastructural changes were believed to the important processes of pathological changes in acute sinusitis.

Microscopic study of certain age-related structural changes of maxillary sinus lining epithelium in albino rats.

Mucociliary clearance is essential to maintain the defense function of the maxillary sinus; however, no literatures described the age changes in its lining epithelium. Therefore, the current work sought to describe the morphological postnatal age-related changes of maxillary sinus lining epithelium in rats using light, transmission, and scanning electron microscopes. Eighteen albino rats were divided into six groups according to their ages: 2-week-old, 1-month-old, 2-month-old, 3-month-old, adults, and senile rats. One-month-old-rats' group was the first to have recognizable maxillary sinus cavities that were lined by either single flat cellular layer or two distinct epithelial layers. These cells were devoid of microvilli and cilia, none of them showed evidence of differentiation into identifiable cell types. In 2- and 3-month-old rats, the mucosa of maxillary sinus started to be lined with pseudostratified epithelium with apparent increase in both microvilli and cilia. The first indication of goblet cell differentiation was observed in 3-month-old-rats. In the adult rats, the sinuses became completely lined by mature respiratory epithelium. However, in senile rats the epithelium exhibited polyps with clumped cilia and some areas of stratification and desquamation. Goblet cells were scanty and degenerating. The impaired mucociliary components (epithelium, cilia, and goblet cells' mucus) found in young and old ages of the current work might be correlated to human to explain predisposition of rhino-sinusitis in these age groups.

Experimental study on histological changes in the sinus membrane following sinus lift.

UNLABELLED: The aim of this study is to assess the histological changes in the sinus mucosa adjacent to the alloplastic material used for subantral augmentation. MATERIALS AND METHODS: The study included ten sheep and a dog. The first group of five sheep underwent a sinus lift procedure, using PerioGlas as an augmentation material; the second similar group of sheep was the control group. The dog underwent a sinus lift procedure, with PerioGlas augmentation, after the sinus membrane was intentionally perforated and two implants were placed in the same operative step. RESULTS: Scanning electron microscopy (SEM) of the sinus mucosa in the control group revealed cells without cilia between goblet cells. The cilia were uniformly arranged in sections in the same direction. Changes occurred in the sinus mucosa after grafting, such as drastic reduction of ciliated cells, which seemed to be replaced by goblet cells. In all sheep undergoing grafting, generalized fibrosis was found in the mucosal area that came into contact with PerioGlas. In two of the sheep in which grafting was performed, mucoid cysts with pseudo stratified ciliated epithelium were present. Even when the sinus mucosa was perforated (in the dog), the inflammatory process developed in the mucosa did not prevent the integration of the graft and implants. In conclusion, following the sinus lift procedure, changes occur in the sinus membrane to adapt to the new situation, without the appearance of chronic or acute suppurative processes.

[Structure of maxillary sinus mucous membrane under normal conditions and in odontogenic perforative sinusitis].

Methods of light, electron microscopy and immunohistochemistry were used to study the samples of maxillary sinus (MS) mucous membrane (MM) under normal conditions and in odontogenic sinusitis. To study the normal structure, the samples were obtained at autopsy from 26 human corpses 12-24 hours after death. Electron microscopic and immunohistochemical study was performed on biopsies of grossly morphologically unchanged MS MM, obtained during the operations for retention cysts in 6 patients. MS MM in perforative sinusitis was studied using the biopsies obtained from 43 patients. The material is broken into 4 groups depending on perforative sinusitis duration. Under normal conditions, MS MM is lined with a pseudostratified columnar ciliated epithelium. Degenerative changes of ciliated epithelial cells were already detected at short time intervals after MS perforations and become apparent due to reduction of specific volume of mitochondria and, rough endoplasmic reticulum, and increase of nuclear-cytoplasmic ratio. In the globlet cells, the reduction of nuclear-cytoplasmic ratio was associated with the disturbance of the secretory product release. At time intervals exceeding 3 months, epithelium underwent metaplasia into simple cuboidal and stratified squamous keratinized, while in MS MM lamina propria, cellular infiltration was increased. CD4+ cell content in sinus MM gradually increased, while at late periods after perforation occurrence it decreased. Low CD4+ cell count within the epithelium and the absence of muromidase on the surface of MS MM was detected. With the increase of the time interval since MS perforation, the number of CD8+ and CD20+ cells in MS MM was found to increase.

The maxillary sinus after total laryngectomy: an electron microscopic study.

Nasal breathing is completely ceased after total laryngectomy. This results in some structural changes in the nasal mucosa, which has been described in numerous studies. This study investigates the changes that appear in the paranasal sinus mucosa. Eight patients who had undergone total laryngectomy at least 1-year ago were enrolled. Under general anesthesia, maxillary sinuses were examined with an endoscope inserted through canine fossa. 1-2 mm mucosal tissues for biopsy were taken from posterior wall of the maxillary sinus. Specimens were evaluated under an electron microscope. Control tissues for biopsy were obtained from two patients who had been operated for other reasons and analyzed under transmission electron microscopy. Results showed that in the control specimens, the epithelial cells appeared normal under transmission electron microscopy. Samples taken from two larygectomees in their first postoperative year were also completely normal. Samples from other larygectomees demonstrated ciliary loss, abundant degenerative vacuoles in ciliated epithelial cells and detachments in the interepithelial junctional complexes. The intracellular respiratory mechanisms such as the mitochondria, golgi complex and endoplasmic reticulum cisternae, and the integrity of the cellular or the nuclear membrane were spared. We conclude that the cessation of nasal breathing resulted in degenerative changes that could be reversible in the transmission electron microscopic examination of maxillary sinus mucosa. These changes emerged after 2 years following total laryngectomy. Nevertheless, these changes did not have any negative influence on the clinical outcome in this group of patients.

Back-scattered electron imaging and elemental microanalysis of retrieved bone tissue following maxillary sinus floor augmentation with calcium sulphate.

OBJECTIVES: To investigate the presence and composition of residual bone graft substitute material in bone biopsies from the maxillary sinus of human subjects, following augmentation with calcium sulphate (CaS). MATERIAL AND METHODS: Bone cores were harvested from the maxillary sinus of patients who had undergone a sinus lift procedure using CaS G170 granules 4 months after the initial surgery. Samples from seven patients, which contained residual biomaterial particles, were examined by field emission scanning electron microscopy and energy dispersive X-ray spectroscopy was used to determine the composition of the remaining bone graft substitute material. RESULTS: Residual graft material occurred in isolated areas surrounded by bone and consisted of individual particles up to 1 mm in length and smaller spherical granules. On the basis of 187 separate point analyses, the residual material was divided into three categories (A, B and C) consisting of: A, mainly CaS (S/P atomic% ratio > or =2.41); B, a heterogeneous mixture of CaS and calcium phosphate (S/P=0.11-2.4) and C, mainly calcium phosphate (S/P< or =0.11; C), which had a mean Ca : P ratio of 1.63+/-0.2, consistent with Ca-deficient hydroxyapatite. Linescans and elemental maps showed that type C material was present in areas which appeared dense and surrounded, or were adjacent to, more granular CaS-containing material, and also occurred as spherical particles. The latter could be disintegrating calcium phosphate in the final stages of the resorption process. CONCLUSIONS: CaS resorption in the human maxillary sinus is accompanied by CaP precipitation which may contribute to its biocompatibility and rapid replacement by bone.

Histologic changes in the maxillary sinus membrane after sinus membrane elevation and the simultaneous insertion of dental implants without the use of grafting materials.

OBJECTIVE: The aim of this study was to evaluate the histologic changes in the maxillary sinus membrane after sinus membrane elevation and the simultaneous insertion of dental implants without additional grafting material. STUDY DESIGN: In 6 mongrel dogs, bilateral edentulated flat alveolar ridges were created in the maxilla. After 3 months of healing, an implant was unilaterally placed in the maxillary sinus in such a way that it protruded 5 mm into the maxillary sinus after sinus membrane elevation. On the opposite side, the maxillary sinus was left untreated as a control site. The animals were killed 6 months after surgery. The maxillary sinus mucosa was examined using light microscopy and scanning and transmission electronic microscopy. RESULTS: There were no morphologic or ultrastructural differences in the sinus membrane between groups. CONCLUSION: The results indicate that the surgical procedure by which implants are inserted into the sinus cavity by elevating the sinus membrane without adding any graft material appears to have little influence on the histologic characteristics of the sinus membrane.

Bone changes after maxillary sinus surgery: an experimental scanning electron microscopy study.

AIMS: The purpose of this study was to explore the pathogenic role of bone in sinus surgery, and to determine whether mucosal disease after sinus surgery may be induced by underlying disease within the bone. MATERIAL AND METHODS: Twenty-five rabbits were divided into five groups. In group one, wide surgical removal of the maxillary sinus mucosa and creation of a nasoantral window were undertaken. In group two, only nasoantral window creation was undertaken. In group three, the mucosa of the anterior maxillary sinus was removed. In group four, a strip of mucosa around the ostium was removed. Group five was used as a control. RESULTS: After three months, in the groups which had undergone wide surgical removal, the medial sinus walls were observed to be retracted and the inner curtain of the bone disturbed, with alteration of the haversian canal system and osteoclastic bone resorption. CONCLUSIONS: After radical sinus surgery, electron microscopic changes were observed in the bony walls, similar to those changes seen in osteomyelitis.

Early bone formation in human bone grafts treated with platelet-rich plasma: preliminary histomorphometric results.

The aim of this study was to evaluate the effect of platelet-rich plasma (PRP) on early and late bone healing after autogenous maxillary sinus grafting. Eleven patients were subjected to sinus augmentation with particulated autogenous bone bilaterally with the addition of PRP in one side. Platelet counts in baseline whole blood and PRP were registered. Biopsies were taken in the grafted bone of the sinus area with trephine at 3 months (nine patients) and simultaneously a micro-implant was installed in the same region. The micro-implants with surrounding bone were retrieved by biopsy at 6 months (seven patients). Undecalcified cut and ground sections were histomorphometrically analysed. Quantification of new and old bone in all biopsies was performed. The results of this histological study showed that significantly more new bone was formed at PRP-treated sites compared to controls after 3 months of healing. After 6 months, this effect could no longer be observed. This is in accordance with previous studies showing that PRP has a rather low regenerative capacity but may influence the early phase of bone healing. The additional value of PRP in autogenous bone grafts in the maxillary sinus is questionable.

Rehabilitation of surgically traumatized paranasal sinus mucosa using retinoic acid.

BACKGROUND: Paranasal sinus mucosa that regenerates after surgical stripping is characterized by sparse, dysmorphic cilia. Although such dysfunctional mucosal changes are thought to be irreversible, the potential rehabilitation of deciliated mucosa by topical therapies has not been explored. This study evaluated the effect of topical retinoic acid (RA) in rehabilitating deciliated sinus mucosa that has regenerated after surgical stripping. METHODS: Twelve New Zealand rabbits underwent bilateral maxillary sinus mucosal stripping and were allowed to remucosalize for 10 days. In the first treatment arm (n = 6), 0.01% RA was applied to the regenerated mucosa of the left maxillary sinus and an aqueous control was placed contralaterally. In the second treatment arm, the regenerated mucosa was surgically restripped bilaterally before applying RA and control. After 14 additional days, mucosa was harvested and examined by scanning electron microscopy for ciliary density, orientation, and morphology. RESULTS: In the first treatment arm, no significant differences in ciliary density, orientation, or morphology were noted between RA-treated sinuses and controls. In the second arm, RA-treated sinuses showed improved ciliary density, morphology, and orientation compared with controls. CONCLUSION: RA does not appear to significantly enhance ciliogenesis when applied after mucosal regeneration has occurred. However, if deciliated mucosa is restripped and allowed to regenerate in the presence of RA, ciliary ultrastructural features may be enhanced. RA may have therapeutic value in rehabilitating deciliated sinus mucosa when applied before mucociliary differentiation of regenerating mucosa.

A histologic and histomorphometric evaluation of anorganic bovine bone retrieved 9 years after a sinus augmentation procedure.

BACKGROUND: Anorganic bovine bone (ABB) has been shown to have osteoconductive properties and no inflammatory or adverse responses as grafting materials used in sinus augmentation procedures. Despite these successful results, histologic data in humans over the long-term period are scarce. The purpose of this study was to analyze the histomorphometric data 9 years after surgery in a case of maxillary sinus augmentation using ABB. METHODS: The histologic evaluation was performed in five different thin sections of the specimen, comparing histomorphometric measures for newly formed bone, marrow spaces, biomaterial particles remnants, and number of osteocytes embedded in both trabecular bone and bone tissue near the ABB. The investigation was carried out by means of scanning electron microscopy and brightfield and circularly polarized light microscopy. RESULTS: We observed a mean amount of newly formed bone of 46.0% +/- 4.67%, ABB remnants of 16.0% +/- 5.89%, and marrow spaces of 38.0% +/- 8.93%. The osteocyte index was 4.43 for bone around ABB and 3.27 in the trabecular bone at a distance from the particles. CONCLUSIONS: After 9 years, the tissue pattern appeared composed by residual ABB particles in close contact to the newly formed bone. The bone mineralized matrix around the ABB had collagen fibers randomly oriented and more osteocytes embedded. The results demonstrate both a high level of osteoconductivity and a "biomimetic" behavior over the long term.

Histological evaluation of maxillary sinus mucosa after functional endoscopic sinus surgery.

BACKGROUND: This study was performed to evaluate the histological changes of the maxillary sinus mucosa of patients with chronic rhinosinusitis (CRS) after functional endoscopic sinus surgery (FESS). METHODS: In a cohort study, biopsy specimens were collected from the maxillary sinus of patients submitted for FESS. One year after surgery, patients were clinically reassessed. Patients showing recurrence of disease (group 1) required a revision surgery, through which a second biopsy specimen was collected. Patients showing a favorable clinical response (group 2) were submitted to an outpatient maxillary biopsy through the previous opened middle meatus antrostomy. Biopsy material from four cadavers was used as control. The histological and electron microscope findings were analyzed. RESULTS: At the initial surgery, patients presented many histopathological alterations, such as an inflammatory process infiltrating the submucosa, atypical respiratory epithelium with an important increase in goblet cells, metaplasia, or mixed epithelium. Group 1 patients persisted with the same alterations 1 year later, but ciliary dysmorphy was more accentuated. Group 2 patients presented a predominantly pseudostratified epithelium, but some areas contained an increased number of goblet cells and a reduction in the number of ciliated cells. CONCLUSION: Recovery of the maxillary sinus mucosa of patients with CRS, observed by electron and light microscopy, was incomplete 1 year after endoscopic surgery, even in nonsymptomatic patients; nevertheless, these alterations were more important in symptomatic patients than in asymptomatic patients.

Histologic and ultrastructural analysis of regenerated bone in maxillary sinus augmentation using a porcine bone-derived biomaterial.

BACKGROUND: The purpose of the present study was the histologic and ultrastructural evaluation of a biomaterial composed of cortical pig bone in the form of granules. METHODS: After maxillary sinus augmentation using this biomaterial, 10 specimens were retrieved after 5 months in 10 patients using this biomaterial. The specimens were processed to be observed under light microscopy (LM) and transmission electron microscopy (TEM). Histomorphometric measurements were presented by means +/- standard deviations. RESULTS: LM showed that most of the particles were surrounded by newly formed bone. In some areas, the osteoid matrix was present; however, mainly compact bone was present at the interface. There was no evidence of an acute inflammatory infiltrate. The newly formed bone was 36% +/- 2.8% and marrow spaces were 38% +/- 1.6%, whereas residual grafted material was 31% +/- 1.6%. Under TEM, all phases of bone formation (osteoid matrix, woven, and lamellar bone) were observed in proximity with the biomaterial particles. The bone-biomaterial interface showed a close contact between the porcine bone particles and the surrounding bone that had mainly features of mature bone with numerous osteocytes. A lamina limitans was sometimes present at this interface. CONCLUSIONS: According to our knowledge, this is the first study presenting data on TEM of a porcine bone-derived biomaterial used in sinus augmentation procedures in humans. Our findings show that this is a biocompatible biomaterial that can be used for maxillary sinus augmentation procedures without interfering with the normal reparative bone processes.

Submucosal glands and goblet cells in maxillary sinus surgery: an experimental study in rabbits.

HYPOTHESIS: After sinus surgery poor ciliary activity and disorders in mucus production can lead to an increase in postoperative complications. PURPOSE OF THIS STUDY: To evaluate the changes in the ultrastructure of submucosal glands (SG) and goblet cells (GC) after partial or wide surgical removal of maxillary sinus mucosa (MSM). METHODS: Twenty New Zealand White rabbits were divided in two groups of 10 animals. In group A, the mucosa of the right maxillary sinus (MS) was removed. In contrast, in group B only a strip the mucosa around the ostium was removed. After three months the sinus were opened and the mucosa studied by light-, and scanning- and transmision electron microscopy. RESULTS: After three months in group A all right MS were infected with purulent secretions, and the density of SG with a mean value of 10.4 per mm, standard deviation (SD) 3.36 and GC 81.81 per mm (SD: 3.82). However, in group B the SG were 52.3 per mm (SD: 4.5) and GC 4.45 per mm (SD: 1.23). These results were statistically significant (p < 0.001). Histopathological findings showed in group A, after three months, SG with a fewer number of microvilli in the glandular lumen.