Development of the paratympanic pneumatic system of Japanese quail.

Avian heads are characterized as having two extensive air-filled systems lined with epithelia; the paranasal and paratympanic sinuses. Many diverticula derived from the paratympanic sinus system are known to reticulate with each other to form a single merged pneumatic space within the adult braincase. However, the development of these complex branching and reticulating epithelia has not been examined in detail. In this study, we describe the comprehensive developmental pattern of the paratympanic sinus and its associated soft tissues in a model bird, Japanese quail (Coturnix japonica). The data are derived from three-dimensional reconstructions based on histological sections and soft tissue enhanced micro-CT data. Those data provide the foundation of the complex hierarchical developmental pattern of the paratympanic sinus system. Moreover, associations with other tissues help establish key morphologies that identify each pneumatic entity. This study clarifies the developmental relationships of the ventral portions of the paratympanic sinus system, the siphoneal diverticulum and marginal sinus, based on the ligaments associated with the Eustachian tube. In addition, detailed histological pneumatic morphologies reveal hitherto unknown epithelial diversity, which may be indicative of equally complex developmental processes. We use the pneumatization of the quadrate as an example to support a close relationship with vascular growth and pneumatic epithelia invasion into ossified bone. We confirm pneumatic diverticula never enter into cartilages, possibly due to the absence of vasculature in these tissues. Lastly, we use the concept of a morphogenetic tree as a tool to help present the complex developmental pattern of the paratympanic sinus system and apply it toward inferring pneumatic morphologies in a nonavian theropod braincase.

Sinus hypoplasia in the cystic fibrosis rat resolves in the absence of chronic infection.

BACKGROUND: Sinus hypoplasia is a hallmark characteristic in cystic fibrosis (CF). Chronic rhinosinusitis (CRS) is nearly universal from a young age, impaired sinus development could be secondary to loss of the cystic fibrosis transmembrane conductance regulator (CFTR) or consequences of chronic infection during maturation. The objective of this study was to assess sinus development relative to overall growth in a novel CF animal model. METHODS: Sinus development was evaluated in CFTR-/- and CFTR+/+ rats at 3 stages of development: newborn; 3 weeks; and 16 weeks. Microcomputed tomography (microCT) scanning, cultures, and histology were performed. Three-dimensional sinus and skull volumes were quantified. RESULTS: At birth, sinus volumes were decreased in CFTR-/- rats compared with wild-type rats (mean ± SEM: 11.3 ± 0.85 mm3 vs 14.5 ± 0.73 mm3 ; p < 0.05), despite similar weights (8.4 ± 0.46 gm vs 8.3 ± 0.51 gm; p = 0.86). CF rat weights declined by 16 weeks (378.4 ± 10.6 gm vs 447.4 ± 15.9 gm; p < 0.05), sinus volume increased similar to wild-type rats (201.1 ± 3.77 gm vs 203.4 ± 7.13 gm; p = 0.8). The ratio of sinus volume to body weight indicates hypoplasia present at birth (1.37 ± 0.12 vs 1.78 ± 0.11; p < 0.05) and showed an increase compared with CFTR+/+ animals by 16 weeks (0.53 ± 0.02 vs 0.46 ± 0.02; p < 0.05). Rats did not develop histologic evidence of chronic infection. CONCLUSION: CF rat sinuses are smaller at birth, but develop volumes similar to wild-type rats with maturation. This suggests that loss of CFTR may confer sinus hypoplasia at birth, but normal development ensues without chronic sinus infection.

The effects of choanal atresia on development of the paranasal sinuses and turbinates.

PURPOSE: The objective of this study was to evaluate the volume of paranasal sinuses (PNS) and turbinate in patients with unilateral choanal atresia (CA). MATERIALS AND METHOD: Computed tomography images of PNS in 11 individuals with unilateral CA were evaluated retrospectively. Mucosal thickness and volume of the maxillary, frontal and sphenoidal sinuses were determined, in addition to the volume of the middle and inferior turbinate. The unaffected nasal side of patients was used as a control group for the measurements. The results comprised the measurements of the atresic side compared to those of the healthy side. RESULTS: There was no significant difference between the atresic and healthy side of the nose in patients with CA with respect to mucosal thickness and volume of the PNS (the maxillary, frontal and sphenoidal sinuses) and the middle and inferior turbinate (p > 0.050). CONCLUSION: The complete absence of nasal unilateral airflow had no effect on the development of the PNS and the middle and inferior turbinate. Moreover, mucosal thickness in the sinuses was similar to that in the control group.

Analysis of nasal cavity morphology and nasolabial development of the normal Han ethnic people under age of 12.

OBJECTIVE: This study aims to establish the three-dimensional (3D) reconstruction model of nasal cavity for China's Han ethnic population (0-12 years) by laser scanning and photogrammetry, and thus to elucidate the developmental mechanism of nasal cavity morphology and nasolabial region. PATIENTS AND METHODS: A total of 260 normal people of the Han ethnic aged 0-12 were recruited as subjects, among whom 60 were scanned for nasal cavity morphology in order to get reconstructed models with the computer engineering software. Photogrammetry was performed for the remaining 200 subjects to measure the 7 parameters that reflect vertically or horizontally the anatomical features of the nasolabial region. RESULTS: The interior morphology of nasal cavity was accurately established by 3D laser scanning and photogrammetry with the optimal morphology of nasal cavity simulated through 3D reconstruction. Development of nasal cavity and nasolabial region was also analyzed. CONCLUSIONS: The 3D laser scanning analysis is the ideal method to analyze the interior morphology of nasal cavity by reconstructing the normal interior morphology of nasal cavity and quantitatively analyze the change of nasal cavity morphology with age. Photogrammetry can be applied to conduct the morphological measurement for the nasolabial region and, thus, assessing the development of the nasolabial region with age, which provides information for choosing the timing and options of surgery in treating harelip and nasal deformity.

Orbital fractures in children.

In children, differences in the properties and proportions of bone in the craniofacial skeleton and the lack of development of the paranasal sinuses result in orbital fractures that present differently from those in adults. Facial growth may be disturbed by such injuries and also by surgical intervention, which should therefore be as conservative as possible. However, urgent operation is needed to prevent irreversible changes when fractures of the orbital floor involve entrapped muscle. We present an approach to such injuries.

Three-dimensional morphometric analysis of paranasal sinuses and mastoid air cell system using computed tomography in pediatric population.

OBJECTIVES: To evaluate the volumetric relationship between the mastoid air cell (MAC) and paranasal sinus (PNS) in the pediatric population using three-dimensional reconstruction and the analysis technique of CT. STUDY DESIGN: Retrospective cross-sectional study was conducted at a university-based, secondary referral hospital. METHODS: PNS CT imaging data of 62 children (40 boys and 22 girls; mean age=13.4 ± 4.0 years) was reconstructed to the three-dimensional model with the surface-rendering algorithm (lower threshold of -1024 HU and upper threshold of -318 HU), and subsequently measuring the volume of the three PNSs (frontal, maxillary and sphenoid) and MAC. Hierarchical linear regression analysis was used to control the effect of age. RESULTS: Controlling the effect of age, no significant linear regression relationship was found between the volume of MAC and PNSs. It was observed that PNSs and MAC showed a significant linear relationship with age. The regression slopes of PNSs were larger than that of MAC, especially the growth of maxillary and sphenoid sinuses was faster and larger than that of the frontal sinus and MAC. As the coefficient of determination was extremely small, the aging process itself could not effectively explain the volume variation of PNSs and MAC. CONCLUSION: No interaction was observed in the pneumatization of the three PNSs (frontal, maxillary, and sphenoid) and MAC. It was found that the growths of PNSs and MAC are influenced by age. Further, maxillary and sphenoid sinuses tend to grow faster and become larger than the frontal sinus and mastoid air cell system. Thus, it is verified that environmental factors could be involved in the postnatal pneumatization process of the PNSs and MAC, which might influence MAC to a greater extent than the PNSs.

Microanatomical variation of the nasal capsular cartilage in newborn primates.

The breakdown of nasal capsule cartilage precedes secondary pneumatic expansion of the paranasal sinuses. Recent work indicates the nasal capsule of monkeys undergoes different ontogenetic transformations regionally (i.e., ossification, persistence as cartilage, or resorption). This study assesses nasal capsule morphology at the perinatal age in a taxonomically broad sample of non-human primates. Using traditional histochemical methods, osteopontin immunohistochemistry and tartrate-resistant acid phosphatase procedure, the cartilage of the lateral nasal wall (LNC) was studied. At birth, matrix properties differ between portions of the LNC that ultimately form elements of the ethmoid bone and regions of the LNC that have no postnatal (descendant) structure. The extent of cartilage that remains in the paranasal parts of the LNC varies among species. It is fragmented in species with the greatest extent of maxillary and/or frontal pneumatic expansion. Conversely, greater continuity of the LNC is noted in newborns of species that lack maxillary and/or frontal sinuses as adults. Chondroclasts occur adjacent to elements of the ethmoid bone, along the margin of the nasal tectum, and/or along islands of cartilage that bear no signs of ossification. Chondroclasts are prevalent along remnants of the paranasal LNC in tamarin species (Leontopithecus, Saguinus), which have extensive frontal and maxillary bone pneumatization. Taken together, the morphological observations indicate that the localized loss of cartilage might be considered a critical event at the onset of secondary pneumatization, facilitated by rapid recruitment of chondro-/osteoclasts, possibly occurring simultaneously in cartilage and bone.

[Preliminary study on normal aerification of paranasal sinuses in children].

OBJECTIVE: To explore the normal aerification of paranasal sinuses in Chinese children with magnetic resonance imaging. METHODS: Two hundred and eighty Chinese children aged from 17 days to 14 years without any symptoms related to sinusitis were statistically analyzed in MRI features, including counting the number of paranasal sinus pneumatization and the maximum axial and sagittal area of the left maxillary. RESULTS: The pneumatization rate of maxillary sinus was 85% in children aged from 0 to 1 years. Until 3 years the pneumatization rate of maxillary sinus was 95% and there was no significant difference in boys and girls (χ(2) = 0.741, P = 0.389). The pneumatization rate of maxillary sinus reached 100% after 4 years old. The pneumatization rate of ethmoid sinus was 100% in this study. The pneumatization rate of sphenoid sinus was 0 within 1 year old, 49% within 4 years old and 100% after 7 years old. There was no significant difference in boys and girls on the pneumatization rate of sphenoid sinus (χ(2) = 2.452, P = 0.117). The pneumatization rate of frontal sinus was 0 within 5 years old, 62% within 9 years old and 95% after 10 years old. There was no significant difference in boys and girls on the pneumatization rate of frontal sinus (χ(2) = 0.124, P = 0.724). The axial and sagittal maximum area of maxillary sinus was (689.28 ± 221.79) and (659.76 ± 263.31) mm(2) in girls and (668.13 ± 206.38) and (638.60 ± 207.67) mm(2) in boys. The differences were significant (t = -19.78, P < 0.001; t = -19.89, P < 0.001). CONCLUSION: The study of the development and normal aerification of paranasal sinuses of children can help radiologist make correct diagnosis of paranasal sinuses in children.

Paranasal sinus development in children: A magnetic resonance imaging analysis.

BACKGROUND: The anatomy of the paranasal sinus is significantly different between adults and children, and surgeons must be aware of these differences to safely perform pediatric functional endoscopic sinus surgery. The purpose of this study was to determine the normal dimensions of the paranasal sinuses during development using magnetic resonance imaging (MRI) data compiled from the largest cohort to date. METHODS: The records of 2025 children, aged 0-18 years, who underwent cranial MRI, were examined retrospectively and 1452 patients with no history of sinus disease were included in the study. Coronal, axial, and sagittal images were used to measure the dimensions of the frontal, maxillary, ethmoid, and sphenoid sinuses, and the sinus volume index was measured. Patients were divided into 10 cohorts based on their age at the time of the scan. RESULTS: No difference between left and right one-dimensional measurements and volume indexes for the maxillary, sphenoid, ethmoid, and frontal sinuses was observed in any age group. Initial signs of pneumatization were observed at birth for the maxillary and ethmoid sinuses, at 9 months for sphenoid sinus, and after the age of 5 years for the frontal sinus. CONCLUSION: These results will help physicians correlate the clinical and radiographic findings of pediatric patients who are being evaluated for sinus disease and potential surgical intervention. Knowledge of the variations in the size of the paranasal sinuses is essential for determining the significance of incidental findings.

Volumetric study in the development of paranasal sinuses by CT imaging in Asian: a pilot study.

BACKGROUND AND OBJECTIVES: The volume of the air cavities in the paranasal sinuses is not only the simplest, but also the most important index for paranasal sinus evaluation. However, few volumetric studies have been performed in all age groups. The purpose of the current study was to outline the normal development of paranasal sinuses in all age groups, and to determine normal adult volumetric values by means of computed tomographic (CT) scan of paranasal sinus using volumetric procedures. MATERIALS AND METHODS: A prospective volumetric CT study was conducted with 260 patients (520 sides) <25 years of age by means of three-dimensional reconstruction. RESULTS: The frontal sinuses began to pneumatize at 2 years of age, exhibited a faster growth pattern between 6 and 19 years of age, and the mean volume after full growth was 3.46±0.78 cm(3). The maxillary sinuses were pneumatized at birth in all cases, exhibited a monomodal growth pattern increasing until 15 years of age, and the mean volume after full growth was 14.83±1.36 cm(3). The floor of the sinus was the same level as the floor of the nasal cavity was between 7 and 15 years of age. The ethmoid sinuses exhibited a faster initial tendency to increase until 7 years of age, were completed by 15-16 years of age, and the mean volume after full growth was 4.51±0.92 cm(3). The sphenoid sinuses exhibited a growth spurt between 6 and 10 years of age, were completed by 15 years of age, and the mean volume after full growth was 3.47±0.93 cm(3). CONCLUSION: The results of this study are presented to provide the basis for an objective normal volume of sinus development and for studies involving diseases of the sinuses.

[Comparison of the nasal sinus development of children with or without sinusitis in Yunnan province].

OBJECTIVE: To investigate the nasal sinus development and discuss the relation between sinusitis and nasal development. METHOD: One thousand seven hundred and five healthy children and 1424 children with sinusitis were selected randomly. All children underwent naso sinus computer tomography. Sagittal, coronal and transverse diameters of all sinuses were measured and statistically analyzed. RESULT: The measured sinus diameters of children with sinusitis were longer than that of healthy children (P < 0.01). Pearson analyses revealed a low correlation of age and the history of sinusitis (P < 0.01), and no correlation of gender and the history of sinusitis. There was moderate to high consistency between clinical diagnosis and nasal CT results about sinusitis (P < 0.01). CONCLUSION: These results demonstrated that the differences of sinus development exist between the healthy children and children with sinusitis, and the sinus development in children with sinusitis were better than that of healthy children.

Fate of the nasal capsular cartilages in prenatal and perinatal tamarins (Saguinus geoffroyi) and extent of secondary pneumatization of maxillary and frontal sinuses.

Development of the nasal capsule cartilages was studied in seven Geoffroy's tamarins (Saguinus geoffroyi), including one fetus, five neonates and one infant. Four additional postnatal specimens of the genus were studied (one 5-month-old and three adults) to determine the magnitude of postnatal expansion of the paranasal sinuses. Alcian blue histochemistry and osteopontin immunohistochemistry were employed in selected subadult specimens to characterize cartilage matrix. The fetal S. geoffroyi possesses a continuous nasal capsule, including a zona anularis; the primordial maxillary sinuses are surrounded by cartilage. Secondary pneumatization is in progress in all older specimens, which have sinuses that are more than twofold larger compared to that of the fetus. Results indicate that extensive ossification of the middle part of the nasal capsule (pars intermedia) is occurring in the perinatal timeframe, forming portions of the ethmoid bone. Anteriorly, the nasal capsule comprises isolated fragments in perinatal specimens, which are fewer and smaller in the infant and in a 5-month-old S. midas, and nearby multinucleate cells suggest that osteoclasts break apart these initially continuous elements. Fragments of the pars intermedia and the tectum nasi are found transiently between mucosa and the sites of secondary pneumatization. The maxillary sinus mucosa is highly vascular in most perinatal specimens. Histochemical and immunohistochemical findings show that cartilage of endochondral bones and non-ossifying parts are distinct in the perinatal time period. These results indicate that breakdown of the capsular cartilage precedes secondary pneumatization as previously suggested. There are portions of the cartilage of the recessus maxillaris and tectum nasi that transiently block mucosa from interfacing directly with bone. Vascularization may play a role in the breakdown of cartilages as well as the onset of secondary pneumatization. Since cartilage has the capacity to produce substances that trigger angiogenesis and bone resorption, further detailed characterization of the cartilage bordering sites of secondary pneumatization is merited.

Inflammation of paranasal sinuses: the clinical pattern is age-dependent.

Acute rhinosinusitis (ARS) represents a common disorder, associated with consistent morbidity as well as with a large prescription of antibiotics. ARS has a significant impact on clinical practice; it usually presents with respiratory complaints persisting longer than 10 days and showing no signs of improvement. Throughout the evaluation of 256 pediatric patients (152 males and 135 females, aged between 2 and 15 yr), with ARS confirmed by nasal endoscopy, we have been able to provide evidence that age has a significant influence on clinical patterns in children with ARS.

Clinical presentation of acute rhinosinusitis in children reflects paranasal sinus development.

BACKGROUND: Acute rhinosinusitis (ARS) usually presents with respiratory symptoms that persist for more than 10 days without improving. The aim of the study was to establish whether age may have any influence on the clinical presentation during childhood. METHODS: This prospective study evaluated 287 consecutive children (152 males and 135 females, aged between 2 and 15 years), in whom mild-moderate ARS was clinically suspected. Nasal endoscopy was performed in all of them to confirm the diagnosis. RESULTS: Endoscopy confirmed clinical diagnosis of ARS in 256 patients (89.2%). The age has shown to have significant influence on the clinical presentation pattern. CONCLUSIONS: This study provides evidence that age significantly influences the clinical presentation in children with mild-moderate ARS.

The delta F508 mutation in cystic fibrosis and impact on sinus development.

BACKGROUND: Cystic fibrosis (CF) patients often have widespread inflammatory paranasal sinus disease with an increased incidence of frontal, maxillary, and sphenoid hypoplasia. The most common genetic defect in CF is the delta F508 mutation. The effect of specific CF genotypes on phenotypic sinus development and infections is not well understood. The purpose of this study was to determine whether the homozygous delta F508 mutation is associated with an increased incidence of sinus hypoplasia when compared with other mutations. METHODS: This study is a retrospective review of all adult patients seen at our CF center from 1996 to 2005. Patients > or =18 years old with a CF diagnosis using genetic and sweat chloride testing and sinus CT scans were included. Frontal sinus aplasia/hypoplasia and maxillary and sphenoid sinus hypoplasia were documented using published criteria. Data collected included patient demographics, genetic mutations, and prior sinus surgeries. RESULTS: Forty-five patients were identified with an average age of 32 years (range, 18-48 years). Thirty-one patients had prior sinus surgeries. Delta F508 homozygotes (n = 25) had a significantly increased frequency of underdeveloped frontal (98%), maxillary (70%), and sphenoid (100%) sinuses (p < 0.001) when compared with other mutations (69, 8, and 50%, respectively). CONCLUSION: CF patients homozygous for the delta F508 mutation have a greater incidence of hypoplastic or underdeveloped sinuses. Whether this is secondary to an increased frequency of sinus infections or a phenotypic expression of the genetic mutation itself remains an area for further investigation.

Pediatric functional endoscopic sinus surgery: frequently asked questions.

Pediatric endoscopic sinus surgery is a controversial procedure that has evolved considerably over the past 2 decades. We present a current review of the literature regarding the treatment of children with refractory sinusitis with a focus on the use of endoscopic sinus surgery. Preoperative evaluation, surgical technique, postoperative care, and unusual applications are discussed.

O papel das variantes anatômicas do complexo ostiomeatal na rinossinusite crônica / The role of osteomeatal complex anatomical variations in chronic rhinosinusitis

A tomografia computadorizada constitui, hoje, o método de escolha para a avaliação dos seios paranasais e fossas nasais e de suas variações anatômicas. Postula-se que essas variações possam obstruir as vias de drenagem de muco, predispondo à rinossinusite crônica. Contudo, esse conceito é ainda controverso e a simples presença da variação anatômica não estabelece necessariamente a etiologia da rinossinusite. Dos três subtipos de concha média bolhosa, a variante bulbosa é a única que parece ter forte associação com a geração de sintomas. As dimensões da variação e a sua associação com a obliteração das vias de drenagem do complexo ostiomeatal parecem ser também muito importantes. Sinais tomográficos de doença sinusal do mesmo lado da variação anatômica reforçam a possibilidade de que esta interfira com o processo de drenagem de muco. A tomografia computadorizada permite estudo detalhado das variações anatômicas e é método indispensável na determinação da conduta e no planejamento de estratégias cirúrgicas. A análise tomográfica deve basear-se na identificação das variações, definição de suas dimensões e sua associação com obliteração dos óstios de drenagem e alterações tomográficas sinusais ipsilaterais.

Currently, computed tomography is the method of choice for assessment of paranasal sinuses, nasal fossae and their anatomical variations. Presumably, these variations may induce osteal obstruction, preventing mucus drainage and predisposing to chronic rhinosinusitis. However, this concept is still controversial and the presence of any anatomic variation does not necessarily establish an etiology for rhinosinusitis. Among three subtypes of concha bullosa, just the bulbous type seems to be strongly associated with symptoms. Size and obliteration of osteomeatal complex drainage pathways may be relevant as well. Variations and tomographic signs of sinusal disease occurring on the same side reinforce the likelihood of interference with the mucus drainage process. Computed tomography offers detailed study of anatomical variations and is an invaluable tool for managing clinical decisions and planning surgical strategies. Imaging assessment must be based on identification of variants, definition of their dimensions, as well as on their association with obstruction of drainage ostia and tomographic signs of sinus disease.

Ontogeny and homology of the paranasal sinuses in Platyrrhini (Mammalia: Primates).

The identity and taxonomic distribution of paranasal sinuses among living platyrrhines has remained a contentious issue (e.g., Cave [1967] Am J Phys Anthropol 26:277-288 vs. Hershkovitz [1977] Chicago: University of Chicago Press) largely because the ontogenetic data required for their detection and identification (e.g., Cave [1967]; Maier [2000] Cambridge, UK: Cambridge University Press, 99-132.) were not attainable without sacrificing valuable juvenile and subadult specimens. Non-invasive computed tomography (CT) scanning of ontogenetic series of skulls for 10 platyrrhine genera demonstrates the presence of maxillary and ethmoid sinuses, as well as homologs of the human sphenoid and frontal sinuses. Differences in the latter two sinuses between platyrrhines and hominoids highlight the need for early developmental data in establishing sinus homology. In particular, the identification of homologous recesses in the cartilaginous nasal capsule, from which sinuses later develop, emerges as the critical step. This developmental approach also reveals that the anterior and posterior ethmoid sinuses are each sets of serial homologs, a point which reconciles previous difficulties in establishing sinus homologies across mammalian orders (e.g., Paulli [1900] Gegenbaurs Morphol Jahrb 28:147-178, 179-251, 483-564).

Atmospheric pressure as a force that fills developing bones with marrow and air.

Many theories try to explain the existence and function of paranasal sinuses. This paper is an attempt to correlate process of paranasal sinus development in human with bone pneumatization processes in animals. It is here proposed that this mechanism starts in utero and continues after birth. During endochondral development, a solid hyaline cartilage model transforms into long bones. Central chondrocytes hypertrophy and their lacunae become confluent. Dissolving of the cartilage intercellular matrix forms a primitive marrow cavity. It is soon invaded by the periostal bud. Once circulation is established in the developing bone, the dissolved hyaline matrix can be slowly washed away from the bone cavity. Circulation in the bone cavity can develop slight subatmospheric pressures, similar to negative interstitial pressures in subcutaneous tissues. The amniotic fluid conducts atmospheric pressure to the fetal body. The pressure is trying to fill enlarging bone cavities through the existing vascular openings, or to create new openings. Bone walls of developing paranasal bones are to weak to resist the pressure gradient on their walls. New openings form on the weakest spots allowing airway mucosa to form initial paranasal sinuses. The enlarging cavities of long bones that are remote from the body surface and airway also develop a slightly subatmospheric pressure that fills them with cellular elements. These elements enter bone through the feeding vessels and form bone marrow. During after birth skeletal growth, bone remodeling shapes paranasal sinuses in a process of slow evolution that do not require measurable pressure gradients. When two sinuses come in vicinity, their growth rate declines, since the remaining thin and fragile bone lamella between them does not retract anymore.