Development of the paranasal air sinuses in a South African Population utilising three dimensional (3D) reconstructed models

The anatomy of the paranasal air sinuses (PAS) may vary in form and size across populations, and between the sexes and age (Yun et al., 2011). This study aimed to estimate the volumes of the PAS within a South African population using the latest available radiological techniques. Computerized tomography scans (n=480) were reviewed from the Pietermaritzburg and Durban public and private sector hospitals (KwaZulu-Natal, South Africa). The sample consisted of 276 males, 204 females, with age range 1-25 yrs, representing the two main population groups (black African and white). The age range was divided into eight, three-year cohorts viz. 1-3; 4-6; 7-9; 10-12; 13-15; 16-18; 19-21; 22-25. These scans were processed by axial manual segmentation of the air sinuses using a 3D Slicer Program (http://www.slicer.org) to construct a three dimensional (3D) volume model of each PAS bilaterally, with 3840 3D models developed. Maximum (max.) to minimum (min.) volumes for each PAS was as follows for ages: maxillary [max: 31563.3 mm3(R), 32062.3 mm3(L); min: 49.4 mm3(R), 25.4 mm3(L)], frontal [max: 22908.6 mm3(R), 21289.0 mm3(L); min: 50.6 mm3(R), 30.2 mm3(L)], sphenoid [max: 15844.6 mm3 (R), 15433.7 mm3(L); min: 6.3 mm3(R), 7.3 mm3(L)] and ethmoid [max: 14327.5 mm3(R), 13162.0 mm3(L); min: 18.9 mm3(R), 12.6 mm3(L)]. This demonstrated that the maxillary was the largest and the ethmoid the smallest PAS at full growth. At 1-3 years of age, the maxillary air sinus was the largest and the sphenoid air sinus was the smallest. Growth of the air sinuses correlated positively with age. Mean volumes appear to be larger on the left side at full growth, although not statistically significant. Sexual dimorphism was statistically significant for the right frontal sinus. Regarding population groups, notable volume differences were observed in the maxillary sinus bilaterally and left sphenoid sinuses unilaterally. There appeared to be four distinct periods in which the growth of the PAS changed. From ages 1 to 7 years there was a gradual increase with a peak increase from 7 to 9 years, continually increasing in growth rapidly, reaching a maximum by 16 to 18 years of age followed by a plateau thereafter. This study presented data of the PAS of the South African populations using 3D reconstructed models. It is apparent that a study consisting of a large sample of 3D models of the PAS has not been fully reported. In particular, the volume of the ethmoid air sinus from 1 to 25 years of age was documented, which was not fully described. The study confirmed differences in terms of the paranasal air sinuses’ size across populations, particularly the maxillary and sphenoid air sinuses, and sex differences viz. the right frontal air sinus

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Development of the ethmoid in Caluromys philander (Didelphidae, Marsupialia) with a discussion on the homology of the turbinal elements in marsupials.

Homology of turbinals, or scroll bones, of the mammalian ethmoid bone is poorly known and complicated by a varied terminology. Positionally, there are two main types of ossified adult turbinals known as endoturbinals and ectoturbinals, and their cartilaginous precursors are called ethmoturbinals and frontoturbinals, respectively. Endoturbinals are considered to be serially homologous due to similarity in their developmental patterns. Consequently, endoturbinals from mammals with differing numbers of elements cannot be individually homogenized. In this study, the development of the ethmoid of Caluromys philander, the bare-tailed woolly opossum, is described based on serial sections of six pouchlings ranging in age from 20 to 84 days postnatal (PND-84), and computed tomography images of an adult skull. I found that four ethmoturbinals initially develop as seen in PND-20 and PND-30 individuals but by PND-64 an interturbinal (corresponding to endoturbinal III in adults) is present between ethmoturbinals II and III. This developmental pattern is identical to that of Monodelphis domestica, the gray short-tailed opossum, and is probably also present in the marsupials Didelphis marsupialis, and Thylacinus cynocephalus based on work of previous authors. These data suggest that endoturbinal III has a developmental pattern that differs from other endoturbinals, and the name interturbinal should be retained for the adult structure in recognition of this difference. These results may prove useful for homologizing this individual turbinal element across marsupials, the majority of which have five endoturbinals as adults. This might also explain the presumed placental ancestral condition of four endoturbinals if the marsupial interturbinal is lost.

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.

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).

[Configuration of ethmoid roof in children 0-14 years of age]. / Siebbeindachkonfiguration bei Kindern im Alter von 0 bis 14 Jahren.

BACKGROUND: Knowledge of the unique anatomy of the nose, paranasal sinuses and skull base, particular concerning dangerously low positioned or deep lying cribriform plates is most important, as functional endoscopic sinus surgery has become an increasingly popular procedure for the management of pediatric sinus disease. OBJECTIVES AND METHODS: In addition to Keros who studied the ethmoidal roof and cribriform plate in 450 adult specimen and divided them into 3 groups, retrospective analysis in 272 patients between 0 and 14 years was performed by means of coronal CT scans of the paranasal sinuses with a slice thickness of 2 mm. Measurements were carried out in the frontal, middle and dorsal section of the ethmoid. RESULTS: The depth and width of the fossa olfactoria were significantly less in patients aged 0 - 12 months than in other age groups (p < 0.001). Among the other age groups, beginning at 2 years no differences were found: 14.2 % presented with type I according to Keros, 70.6 % with Keros II and 15.2 % with Keros III. The prevalence of asymmetric position of the ethmoidal roof was 15 % (41 patients). The height of the ethmoidal sinuses consistently increased over the years from 5 - 7 mm to 15 - 20 mm. CONCLUSION: The current data may serve as a reference for evaluation of normal and abnormal development of the roof of the ethmoid and may be of great value in diagnostic and therapeutic management of pediatric sinus disease. Our data obviously show that the classification into the 3 types of positions of the ethmoid roof and cribriform plate according to Keros is possible in children from the second year of life.

[Development of the spheno-ethmoid paranasal sinus system using axial computerized tomography imaging]. / Die Entwicklung des spheno-ethmoidalen Nasennebenhöhlensystems in der axialen computertomographischen Darstellung.

BACKGROUND: Exact knowledge of age- and sex-related development of the paranasal sinuses is essential to assess their role in infantile diseases in the midface region. Moreover it helps to minimize the risk in case of therapeutic intervention. METHODS/PATIENTS: On the basis of more than 5600 axial computed tomographic images (CT images) we evaluated the sex-related size (width and length) and evidence of the different sinuses from birth to age 25 focussing on the central part of the paranasal sinuses, the ethmoidal cells, and the sphenoidal sinuses. RESULTS/CONCLUSIONS: The sphenoethmoidal complex is of special interest in early ages since it is already completely developed in newborns (ethmoidal cells: 94% for both sexes) or at least shows a rapid development during the first decade. After age 8, both sinuses are almost regularly represented on CT with identical percentages as an indication of common origin. This is confirmed by only slight differences in size between the two sexes (ethmoidal cells: 5,7 - 10,1%: sphenoid sinuses: 5,4-9,7%) after termination of expansion and by similar periods of expansion (ethmoid cells: until age 10, female, to 14, male and female in length; sphenoidal sinuses: until age 14, female, to 15, male and female) which partly differ from the other sinuses. However, the difference between male and female sinuses is statistically significant primarily at later ages (age 25: length of sphenoidal sinuses: p < 0.0001/width of ethmoidal cells: p = 0.0117/length of ethmoidal cells: p = 0.0072). The definitive size of the ethmoidal cells (male: width 16.4 mm x length 40.7 mm: female: 14.9 mm x 38.5 mm) agrees with the results obtained from anatomic and radiologic studies. In contrast, we found substantial variability in both directions (up to 214%) for the sphenoidal sinuses. Since on almost 60-70% of the CT images the intersphenoidal septum was not represented, we can provide more detailed data about the whole sphenoidal complex (male: width 31.0 mm x length 24.5 mm; female: 29.4 mm x 26.9 mm). In conclusion, our findings agree with the data from other studies using different methods. Moreover we can determine size of the different sinuses at any time between birth and age 25 for both sexes. The ethmoidal cells and the sphenoidal sinuses are highly significant in early infantile paranasal sinus diseases.

Variations of the ethmoid labyrinth and sphenoid sinus and CT imaging.

Three hundred macerated and partly isolated postmortem mid-facial bones were studied for the development, variations and dimensions of the structures of the nasal cavity. On 184 axial CT scans of bones (102 male, 82 female) from patients ranging in age from 1 to 90 years old, the dimensions of the ethmoid labyrinth and sphenoid sinus were studied in detail in order to determine which anatomic situation might be unsafe during clinical endoscopic interventions. Six anatomic variations were identified. Most unsafe for surgery seemed to be the following types: type III, in which the anterior diameter of the ethmoid labyrinth was large and the posterior ethmoid and sphenoid diameters were relatively narrow; type V, in which both ethmoid dimensions were large and the sphenoid diameter was narrow: type VI, in which the ethmoid labyrinth had an "hour-glass" shape. Present findings indicate that CT orientation before any endoscopic intervention might help to avoid serious complications.

Development of the ostiomeatal unit in childhood: a radiological study.

The role of surgery in the management of sinus disease is in a state of evolution. With the advent of the endoscope, functional sinus surgery has become a reality. This type of surgery is recently being utilized as a therapeutic modality for sinus disease in children. The sinus surgeon should be aware of the differences between adult and pediatric sinus anatomy. This study utilizes the CT scanner to chart the anatomy and development of the ostiomeatal unit area in childhood, from the age of one through 16. This study may provide a more comprehensive understanding of the ostiomeatal unit in the pediatric population.

Paranasal sinuses in pediatric patients by MRI: normal development and preliminary findings in disease.

A two-part study using medium field strength magnetic resonance imaging (MRI) was designed to describe the normal paranasal sinus development and to provide preliminary criteria for clinical sinus disease. In part I of the study the paranasal sinuses were retrospectively evaluated in 80 infants and children aged 0-17 years undergoing brain MRI for indications both unrelated and related to sinus disease. We developed MRI criteria for independent grading of paranasal sinus development and 'anatomical' sinus disease, i.e., disease as seen by the radiologist. We quantified the variability in extent of sinus pneumatization (a measure of sinus development) in infants and young children. Part II of the study was a double-blind prospective study in 21 patients to correlate 'anatomical' disease with 'clinical' sinus disease. In this limited preliminary study, clinical sinus disease was only seen in the patients with moderate or severe anatomical disease (sensitivity 100%; specificity 100%).

Significance of opacification of the maxillary and ethmoid sinuses in infants.

To evaluate the incidence and significance of radiographic sinus opacification in infants, we performed computed tomography (CT) of the maxillary and ethmoid sinuses in conjunction with routine cranial CT in 100 infants from birth to 12 months of age. CT was performed for indications other than sinusitis. Prospective concurrent clinical history was obtained and physical examination of the upper respiratory tract was performed. Of 100 infants, 16 had hypoplasia of the maxillary sinuses; 81% (13/16) of these were less than 2 months of age. The antra showed progressive increase in size during the first year of life. Of the 100 infants, 70 had CT sinus opacification, including 67% of those without historical or physical evidence of upper respiratory tract infection. There was a positive correlation of CT findings between the maxillary and ethmoid sinuses in 80% of the infants older than 2 months of age but in only 49% of the younger infants. Radiographic sinus opacification in infants is of uncertain significance and is not diagnostic of upper respiratory tract infection, much less of sinusitis.