Radiologic changes in the aging nasal cavity.

BACKGROUND: With an aging population, it is important to understand age-related anatomic changes in the nasal cavity and cribriform plate (CP) that may have clinical implications. METHODOLOGY: Computed tomography (CT) scans obtained for non-rhinologic conditions were divided into a young cohort (N=35, 18-34 years old) and an older adult cohort (N=32, 80-99 years old). Intranasal airspace volumes and bony anatomy of the CP were manually segmented using OsiriX software. The CP was assessed for mean Hounsfield Units (HU) and percentage of olfactory foramina. Deformation based morphometry (DBM) was then performed on the same cohort and correlated with manual measurements. RESULTS: Individual nasal cavity volumes increased 17-75% with age. Regression analysis of all scans revealed age to be the predominant variable influencing intranasal volume differences when controlling for sex and head size. Mean HU of the CP negatively correlated with age. No age-related differences in bone stenosis of olfactory foramina were identified. Automated DBM measurements of intranasal volumes, as well as CP and zygoma mean HU correlated with manual measurements. CONCLUSION: Older subjects have a global increase in intranasal volumes and diffuse bone density loss in the CP. The clinical impact of age-related anatomic changes in the nasal cavity and CP requires further investigation.

Temporal Progression of Craniofacial Dysmorphology in Unilateral Coronal Synostosis: A Mechanistic Hypothesis.

AIM: This study chronicles skull base and face development in nonsyndromic unilateral coronal synostosis (UCS) during infancy, to characterize the mechanistic progression of facial dysmorphology. METHODS: Computed tomography scans from 51 subjects were reviewed (26 UCS, 25 controls) and data were reconstructed. Patients were stratified into 5 age groups. A series of measurements were taken from the reconstructions. RESULTS: All patients had a unilaterally fused coronal suture at the time of analysis. Asymmetry of the sphenoid wings was present across all age groups. The sphenoid wing ipsilateral to the fused suture consistently had a more acute angle from the midline. At 19 days of age, ipsilateral nasal root and cribriform plate deviation are noted, as well as increased contralateral zygoma antero-posterior length. Patients younger than 2 months also had elongated posterior cranial bases. At 2 to 3 months of age, the cranial base widens in the anterior portion of the middle cranial fossa with an increased ipsilateral pterion to sella distance. The most delayed change observed was the increase in contralateral orbital rim angle at 7 to 12 months of age compared to normal. CONCLUSION: After suture fusion, sphenoid wing changes are among the earliest restructural malformations to take place. This suggests that the cascade of dysmorphology in UCS originates in the cranial vault, then progresses to the skull base, and lastly to the facial structures. Ipsilateral orbital changes are early facial changes in UCS that begin before 2 months of age. This is then followed by changes in the contralateral face later in development.

Distinct requirements for wnt9a and irf6 in extension and integration mechanisms during zebrafish palate morphogenesis.

Development of the palate in vertebrates involves cranial neural crest migration, convergence of facial prominences and extension of the cartilaginous framework. Dysregulation of palatogenesis results in orofacial clefts, which represent the most common structural birth defects. Detailed analysis of zebrafish palatogenesis revealed distinct mechanisms of palatal morphogenesis: extension, proliferation and integration. We show that wnt9a is required for palatal extension, wherein the chondrocytes form a proliferative front, undergo morphological change and intercalate to form the ethmoid plate. Meanwhile, irf6 is required specifically for integration of facial prominences along a V-shaped seam. This work presents a mechanistic analysis of palate morphogenesis in a clinically relevant context.

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.

Growth and Development at the Sphenoethmoidal Junction in Perinatal Primates.

Integration of the sphenoid and ethmoid bones during early postnatal development is poorly described in the literature. A uniquely prolonged patency of sphenoethmoidal synchondrosis or prespheno-septal synchondrosis (PSept) has been attributed to humans. However, the sphenoethmoidal junction has not been studied using a comparative primate sample. Here, we examined development of the sphenoethmoidal interface using ontogenetic samples of Old and New World monkeys, strepsirrhine primates (lemurs and lorises), and a comparative sample of other mammals. Specimens ranging from late fetal to 1 month postnatal age were studied using histology, immunohistochemistry, and micro-computed tomography methods. Our results demonstrate that humans are not unique in anterior cranial base growth at PSept, as it is patent in all newborn primates. We found two distinctions within our sample. First, nearly all primates exhibit an earlier breakdown of the nasal capsule cartilage that abuts the orbitosphenoid when compared to nonprimates. This may facilitate earlier postnatal integration of the basicranium and midface and may enhance morphological plasticity in the region. Second, the PSept exhibits a basic dichotomy between strepsirrhines and monkeys. In strepsirrhines, the PSept has proliferating chondrocytes that are primarily oriented in a longitudinal plane, as in other mammals. In contrast, monkeys have a convex anterior end of the presphenoid with a radial boundary of cartilaginous growth at PSept. Our findings suggest that the PSept acts as a "pacemaker" of longitudinal facial growth in mammals with relatively long snouts, but may also contribute to facial height and produce a relatively taller midface in anthropoid primates. Anat Rec, 300:2115-2137, 2017. © 2017 Wiley Periodicals, Inc.

Anuran postnasal wall homology: an experimental extirpation study.

The nasal placode was extirpated unilaterally in Gosner stage 18-20 embryos of Rana sylvatica, R. palustris and R. pipiens, in order to test alternative proposed schemes of homology for the ethmoidal attachment of the palatoquadrate in anurans and urodeles. Absence of the nasal sac has no pronounced effect on the formation of larval chondrocranial structures. In contrast, in metamorphosed animals the lamina orbitonasalis and inferior prenasal process are the only nasal capsule structures present on the operated side. The medial nasal branch of the deep ophthalmic nerve passes forward over the dorsal surface of the lamina orbitonasalis, rather than through an orbitonasal foramen. Comparison with previous experimental work on urodeles supports the traditional homology of the anuran lamina orbitonasalis with the antorbital process of urodeles and other vertebrates.

Description of the chondrocranium and osteogenesis of the Chacoan burrowing frog, Chacophrys pierotti (Anura: Leptodactylidae).

The larval chondrocranium of the large-headed leptodactylid frog, Chacophrys pierotti (Ceratophryinae), is described in detail. Descriptions include the ontogeny of the chondrocranium and osteogenesis of the cranial skeleton. The chondrocranium of C. pierotti is profoundly different from the chondrocrania previously described for the other genera of the Ceratophryinae (Ceratophrys and Lepidobatrachus). The chondrocranium of Chacophrys is longer than wide and not particularly robust or laterally expanded; that of Ceratophrys is very robust, whereas the chondrocranium of Lepidobatrachus is widely expanded laterally. These differences are particularly apparent in the elements associated with the jaw (i.e., suprarostral, infrarostral, Meckel's cartilage, palatoquadrate, cornua trabeculae), which are robust in Ceratophrys and thin and elongate in Lepidobatrachus. Unlike Ceratophrys and Lepidobatrachus, which possess highly specialized carnivorous larva, the chondrocranium of Chacophrys more closely resembles the typical microphagous herbivore morphology characteristic of other leptodactylid frogs for which the chondrocrania are known. These data suggest that Chacophrys is the basal taxon within the monophyletic Ceratophryinae. The ontogeny of the chondrocranium of Chacophrys, as well as the cranial ossification sequence, do not differ greatly from those described for Ceratophrys. Detailed descriptions of the ontogeny of the chondrocranium and the bony skeleton are needed for additional taxa within the Ceratophryinae (especially Lepidobatrachus). Such descriptive ontogenetic studies promise new insight into the phylogeny and morphological evolution of this remarkable group of large-headed frogs.

Evaluation of the result of surgery on cleft lip and palate and skeletal growth determinants of the cranial base.

In evaluating the results of surgery on cleft lip and palate, the growth determinants have to be taken into consideration. The goal should be that the dentoalveolar conditions coincide with the growth tendencies at the base of the skull upon termination of growth. If there is a tendency at the cranial base to class III, most likely it will not be possible to achieve a dentoalveolar angle class I without osteotomies.

Experimental unilateral coronal synostosis in rabbits.

Immobilization of the coronal suture was produced unilaterally in 9-day-old rabbits to determine its effect on subsequent craniofacial development. The suture was immobilized unilaterally by the topical application of methylcyanoacrylate adhesive. Subsequent growth effects on the cranial vault, base, and facial skeleton were assessed by serial radiographic cephalometry. Unilateral coronal suture immobilization resulted in significantly decreased bone growth at the coronal suture (mean 0.95 mm +/- 0.35 SE) when compared to sham-treated control animals (mean 5.06 mm +/- 0.20 SE). Frontonasal suture bone growth contralateral to the immobilized half of the coronal suture, however, was significantly increased. The anterior cranial base became significantly shortened, and orbital asymmetry developed. The pattern of induced abnormalities simulates unilateral coronal synostosis in humans.

Surgery of the lateral nasal wall and ethmoid: effects on sinonasal growth: an experimental study in rabbits.

OBJECTIVE: To assess the impact of lateral nasal wall surgery on sinonasal growth METHODS: Twenty young New Zealand White rabbits, 6 weeks of age, were included in this experimental study. Surgery was performed on two groups of ten animals each (series I and II). Entrance to the left nasal cavity is achieved through the nasal dorsum via mobilization and rotation of the left nasal bone. Series I: partial resection of the lateral nasal wall (including the ostium to the maxillary sinus) on the left side. Series II: partial resection of the lateral nasal wall and anterior ethmoid. Follow-up period was 20 weeks. Twenty rabbits served as controls. RESULTS: In series I, all skulls have grown normally. In series II the nasal dorsum has also developed symmetrically. Snout length and growth of upper jaw are normal; there is no malocclusion. Three skulls show a slight deviation of the nasal dorsum (two to the left, one to the right). Morphometric measurements of 20 points on the skulls show no significant difference between the control group and the experimental series I and II. CONCLUSION: This experimental study demonstrates that visually controlled partial resection of the bony sinonasal wall, with or without resection of the anterior ethmoid does not affect later development of nose and upper jaw on condition that eventually underlying cartilage is preserved. Contradictory results from other experimental studies, previously published and concerning negative effects of sinus surgery, might be attributed to surgical traumatization of intranasal cartilage structures, in particular, the upper lateral cartilages.

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.

Development of the cribriform plate and of the lamina mediana.

The development of the cribriform plate and lamina mediana was studied in macerated isolated ethmoid bones in specimens from late fetal life to the stage of its final shape (60 specimens). From fetal life to the first year of age, the ethmoid bone consisted of two separate symmetrical halves which had joined together by the end of the first year. Each half of the future ethmoid bone incorporated the superior, middle and occasionally also the supreme nasal concha. The ossification of the cribriform plate started in the new-born where it initially displayed a vertical position but became horizontal in the course of the first year. At the end of the first year both halves of the ethmoid bone had been united by the formation of the crista galli, lamina mediana and complete ossification of the cribriform plate. The lamina mediana reached its final shape by ten years of age. Each half of the ethmoid bone displayed furrows for the fila olfactoria in the region of the superior and occasionally also of the anterior part of the middle nasal concha. The furrows run in a postero-anterior direction. In the course of our investigations we found three cases where all three nasal conchae formed a unique block thus proving the common origin of these structures from the cartilaginous nasal capsule.

[Organization of the bone system of the nasal septum and its homologues. V]. / Organizacja zrebu kostnego przegrody nosa oraz jej homologów.V.

The aim of these anatomo-comparative investigations was the differentiation and systematization of the osseous nasal septum and vomer complex in rhesus monkeys (Catarrhina). ). The material consisted of 66 monkey heads: 52 of the fixed in formaline solution and 14 naturally macerated. The methodology was described elsewhere (part--1). The nasal osseous system philogenetically was presented in rhesuses only by alar bone. As lower--secondary part of septum emerges the typical parasphenoid complex. The alar bone in monkeys is homologous monominal elements (septal and subnasal bones) in pairhoofed mammals, birds, fishes and amphibians. It proves that in rhesuses as others Craniota the "mesoethmoid" and "ethmoidal bone" do not exist. In the skull of these monkeys the axially palate system was proved. This system does not dominate in the mechanics of the splanchnocranium.

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.

Development of the ethmoidal structures of the endocranium in Discoglossus pictus (Anura: Discoglossidae).

We use histological techniques and computer-aided three-dimensional reconstructions made from serial histological sections to describe the ontogeny of the ethmoidal endocranium of discoglossid frog Discoglossus pictus. We identify a pattern of development for the suprarostral cartilage that differs from previous findings and probably represents the ancestral anuran pattern. The nasal cartilages, including the inferior prenasal cartilage, are de novo adult structures. The only larva-derived structures of the adult nasal capsules are the posterior aspects of the solum nasi and septum nasi. We also identify patterns of development for the ethmoid plate and postnasal wall that occur during early in ontogenesis. These patterns are associated with development events during metamorphic climax. The pattern of timing of chondrification of the anterior nasal cartilages more closely coincides with that of the neobatrachian species than that recorded for the pelobatid frog Spea. In addition, this study supports a sister taxon relationship between Discoglossus and Alytes.

[The size of the ethmoidal labyrinth in children of various ages]. / Razmer reshetchatogo labirinta u detei razlichnogo vozrasta.

The length, height and width of the ethmoidal labyrinth have been measured in children from birth up to 16 years of age (125 osseous total preparations). Coefficients of the regressive equations have been estimated (the sixth degree polynomial) in order to calculate the prognosticated dimentions. The data obtained can be used in surgery.