Jaw Length Research Articles

Sexual dimorphism in size and shape among populations of the lizard Sceloporus variabilis (Squamata: Phrynosomatidae)

Sexual dimorphism in lizards is determined by ecological and environmental factors. Broadly distributed species may show variation in patterns of sexual dimorphism toward either sex, as well as exhibiting variation in morphological dimensions. In the present study, sexual dimorphism in size and shape attributes was evaluated in three populations of the lizard Sceloporus variabilis from different environments in Mexico. We evaluated the size attributes of 10 morphological variables: snout-vent length (SVL), tibia length (TL), femur length (FeL), forearm length (FoL), interaxial distance (ID), head length (HL), head width (HW), head height (HH), jaw length (JL), and jaw width (JW). We also evaluated the attributes of shape (relative dimensions of the 10 morphological variables). In the size attribute, sexual dimorphism was found, with males being larger than females. In the case of shape, sexual dimorphism was found, with the females being larger in relative dimensions of ID and JW. Also, the males showed larger relative dimensions in TL, FeL and FoL. Differences were found between populations in the dimension of the variables analyzed in each sex. The pattern in size can be explained by sexual selection, where the males of each population maintain larger dimensions to compete for territory and access to females. In shape, females can be favored if they have larger relative ID and JW, as it promotes maintenance of clutch sizes, and use of microhabitats and different consumption of prey types than males. In the case of males, relative dimensions of TL, FeL and FoL may be functioning as important traits for escape from predators. The present study shows the importance of incorporating size and shape variables into analyses of sexual dimorphism among populations of a single species with a wide distribution. These types of studies help to identify the causes that promote sexual dimorphism, as well as the degree of difference among populations that inhabit different environments.

Prey Size and Feeding Rate Do Not Influence Trophic Morphology of Juvenile Water Snakes (Nerodia sipedon)

Gape-limited predators, such as snakes, might rely on phenotypic plasticity to cope with variation in prey size, but experimental studies have found mixed evidence for plasticity in snake head morphology. Our study sought to determine whether variation in prey size and feeding rate induce head size plasticity in Northern Water Snakes (Nerodia sipedon). We avoided limitations of previous studies by growing all neonates to a consistent final size (400 mm snout–vent length [SVL]), and uncoupling feeding rate and prey size as potential factors influencing head size through four feeding treatments: big–fast (one large prey item every week), big–slow (one large prey item every other week), small–fast (two small prey items every week), and small–slow (one small prey item every week). Snakes in fast treatments grew faster than snakes in slow treatments, but there were no strong effects of feeding rate or prey size treatments on multiple head size metrics. Females grew faster than males, however, and had longer jaw lengths at 400 mm SVL than did males. Unlike previous studies, our results do not support the presence of phenotypic plasticity in head size in N. sipedon, indicating that head size plasticity in snakes can be species and context specific.

Morphological variations and phylogenetic analysis of Oryzias nigrimas Kottelat, 1990 (Rice fish) from Lake Poso, Central Sulawesi, Indonesia

Abstract. Serdiati N, Arfiati D, Widodo MS, Lelono TJ, Ndobe S, Saranga R. 2020. Morphological variations and phylogenetic analysis of Oryzias nigrimas Kottelat, 1990 (Rice fish) from Lake Poso, Central Sulawesi, Indonesia. Biodiversitas 21: 882-888. Rice fish (Oryzias nigrimas Kottelat, 1990) is a well-studied species endemic to Lake Poso, Sulawesi and identified as scarce. This study aims to identify the Rice fish of Lake Poso, Central Sulawesi based on morphological characters (15 morphometric characters and 5 meristic counts) and phylogenetic analysis using maximum-likelihood (ML) method based on mtDNA, CO1 gene. Based on the morphological analysis, it was showed that the meristic counts show significantly different only on the lateral line scale. However, the morphometric measurements show significantly different characteristics on postorbital distance, body depth, and length of jaw. Our phylogenetic analysis also showed that our samples are indeed a species of O. nigrimas. We suggest that the endemicity of this Rice fish on Lake Poso is greatly influenced by the well-maintained genetic structure of the population.

Impact of temperature on bite force and bite endurance in the leopard iguana (Diplolaemus leopardinus) in the Andes Mountains.

In ectotherms, temperature exerts a strong influence on the performance of physiological and ecological traits. One approach to understanding the impact of rising temperatures on animals and their ability to cope with climate change is to quantify variation in thermal-sensitive traits. Here, we examined the thermal biology, temperature dependence and thermal plasticity of bite force (endurance and magnitude) in Diplolaemus leopardinus, an aggressive and territorial lizard endemic to Mendoza province, Argentina. Our results indicate that this lizard behaves like a moderate thermoregulator that uses the rocks of its environment as the main heat source. Bite endurance was not influenced by head morphometry and body temperature, whereas bite force was influenced by head length and jaw length, and exhibited thermal dependence. Before thermal acclimation treatments, the maximum bite force for D. leopardinus occurred at the lowest body temperature and fell sharply with increasing body temperature. After acclimation treatments, lizards acclimated at higher temperatures exhibited greater bite force. Bite force showed phenotypic plasticity, which reveals that leopard iguanas are able to maintain (and even improve) their bite force under a rising-temperature scenario.

Anatomical similarity between the Sost-knockout mouse and sclerosteosis in humans.

Sclerosteosis, a rare autosomal recessive genetic disorder caused by a mutation of the Sost gene, manifests in the facial skeleton by gigantism, facial distortion, mandibular prognathism, cranial nerve palsy, and, in extreme cases, compression of the medulla oblongata. Mice lacking sclerostin reflect some symptoms of sclerosteosis, but this is the first report of the effect on the facial skeleton. We used geometric morphometrics (GMM) to analyze the deformations of the murine facial skeleton from the wild‐type to the Sost gene knockout. Landmark coordinates were obtained by surface reconstructions from micro‐computed tomography. Centroid size, principal component scores in shape space and form space, and asymmetry were computed by the standard GMM formulas, and dental and skeletal jaw lengths were examined as ratios. We show here that, compared to wild type controls, mice lacking Sost have larger centroid size (effect size, p‐value: 4.59, <.001), higher mean asymmetry (1.14, .065), dental and skeletal mandibular prognathism (1.36, .010 and 5.92, <.001), a smaller foramen magnum (−1.71, .015), and calvaria that are more highly curved (form space p = 4.09, .002; shape space p = 12.82, .002). These features of mice lacking sclerostin largely correspond to the changes of the facial skeleton observed in sclerosteosis. This alignment further supports claims that the Sost gene plays a fundamental role in bony facial development in rodents and humans alike.

Phenotypic diversity in an endangered freshwater fish Squalius microlepis (Actinopterygii, Leuciscidae).

Squalius microlepis was examined from recent and historical collections within the known range of the species with special emphasis on intraspecific variability and variations, and compared to its closest relative species S. tenellus (in total, 193 specimens; 33 absolute and 52 proportional measurements and ratios, and 12 counts including vertebrae). Squalius tenellus was perfectly differentiated in all statistical analyses and can be diagnosed by 76–95 (vs. 64–80) scales in lateral series, 68–83 (vs. 58–77) lateral-line scales, (17)18–20 (vs. 13–16(17)) scales above lateral line, and (7)8–10 (vs. 4–7) scales below lateral line. Squalius microlepis was morphologically heterogeneous, with two phenotypes readily distinguishable (phenotype 1 corresponding to S. microlepis s. str. as defined by its lectotype) by a combination of many characters; those contributing most to the discrimination were number of gill rakers, length of lower jaw (% interorbital width), and head length (% SL). Only phenotype 1 was found in the Ričina-Prološko Blato-Vrljika karst system; most of the specimens from the lower Matica and the Tihaljina-Trebižat karst system were identified as phenotype 2; the sample from karstic poljes near Vrgorac contained both phenotype 1 and 2, and individuals of intermediate morphology. As very limited molecular data exist on the two phenotypes of S. microlepis, we refrain from any taxonomic conclusions until new molecular approaches (and new markers) are used. We also report on a dramatic reduction of the area of distribution and abundance of S. microlepis in recent years.

Skull Sizes and Proportions in Western Palearctic Wood Mice (Sylvaemus, Muridae, Rodentia) from Eastern Europe: 1. Interspecific Variability

Craniometric features (measurements, indexes) in several species of the genus Sylvaemus (S. sylvaticus, S. flavicollis, and S. uralensis from Eastern Europe and some adjacent territories, as well as S. ponticus and S. witherbyi from the Caucasus) have been studied using multivariate statistical analysis. For the first time, craniometric characters of the genus Sylvaemus are considered in relation to the feeding ecology of species. A total of 614 skulls were studied. Based on original material, discriminant keys have been developed using skull measurements. The keys appear to be suitable for the diagnostics of the studied Sylvaemus species, including sibling ones. The largest skulls are shown to be characteristic of S.flavicollis, and the smallest ones, of S. uralensis. Cluster analysis of the absolute measurements of the skull cumulative selection has revealed the greatest isolation of S. flavicollis and the similarity of coexisting but phylogenetically remote S. ponticus and S. witherbyi. Factor analysis showed that, within the genus Sylvaemus, the general sizes are less essential than the characters related to food smashing (the length of the lower jaw and rostrum, the width of the occipital part of the skull), and possibly also to the thickness of the incisors. Comparative analyses of the relative skull measurements (the indexes related to the food preferences of the animals, granivory or folivory) allow us to conclude that the food adaptations to granivory in the structure of the skull and teeth increase in the series S. uralensis–S. sylvaticus–S. witherbyi–S. flavicollis–S. ponticus. The cranial evolution in species within the genus Sylvaemus is suggested to have been directed to increased adaptations in the mechanisms in seed peeling and processing.

Comparative morphology and trophic ecology in a population of the polymorphic lizard Sceloporus minor (Squamata: Phrynosomatidae) from central Mexico.

Polymorphism among individuals of the same population has generally been linked to alternative reproductive tactics, where different morphs can exhibit differences in their morphological, ecological, and behavioral attributes. These differences may result in a divergence in diet between morphs due to differential exploitation of habitat, morphological differences that influence prey selection, or differential energy expenditure that results in different nutritional needs. The present study analyzes the morphology (morphometry and body mass) and diet of red and yellow male morphs in a population (El Enzuelado) of the lizard Sceloporus minor from central Mexico. No differences between morphs were found for any of the morphometric variables analyzed (snout-vent length, tail length, jaw length, jaw width, head length, head width, head height, tibia length, femur length, forearm length and ventral patch length). In both morphs, allometric growth was observed in all body features analyzed, as well as in morphometric features of the head across seasons. Analysis of stomach contents showed that the diet of red males was composed of 12 categories of prey, while that of yellow males was composed of 10 categories; those categories of diet not shared between morphs (e.g., Isoptera, Psocoptera) were consumed by their respective morph in very low proportions. Categories of diet with the highest values of food importance for both groups were Coleoptera, Orthoptera, and leaves; a similar pattern was seen across seasons. This, in turn, is reflected in low niche breadth values for each morph and a very high niche overlap. There were no significant differences between morphs overall, or between morphs per season, in the weight and volume of stomach contents or in the number of prey items found in stomachs; however, differences in these variables across all males (independent of morph) were recorded between seasons. Likewise, no significant correlations were found between body size (snout-vent length) and the volume of stomach contents for either morph or between lizard mandibular dimensions and the volume of stomach contents for red morph males. For the yellow morph, prey volume unexpectedly decreased significantly with jaw size rather than increasing as expected. Overall, this study adds new information about the morphology and feeding of males in this species, and suggests that in this population, color morphs lack the morphological and ecological differences found in some other species of polymorphic lizard.

Re-examination of the effects of food abundance on jaw plasticity in purple sea urchins

Morphological plasticity is a critical mechanism that animals use to cope with variations in resource availability. During periods of food scarcity, sea urchins demonstrate an increase in jaw length relative to test diameter. This trait is thought to be reversible and adaptive by yielding an increase in feeding efficiency. We directly tested the hypotheses that (1) there are reversible shifts in jaw length to test diameter ratios with food abundance in individual urchins, and (2) these shifts alter feeding efficiency. Purple sea urchins, Strongylocentrotus purpuratus, were collected and placed in either high or low food treatments for 3 months, after which treatments were switched for two additional months in La Jolla, CA (32.8674°N, 117.2530°W). Measurements of jaw length to test diameter ratios were significantly higher in low compared to high food urchins, but this was due to test growth in the high food treatments. Ratios of low food urchins did not change following a switch to high food conditions, indicating that this trait is not reversible within the time frame of this study. Relatively longer jaws were also not correlated with increased feeding efficiency. We argue that jaw length plasticity is not adaptive and is simply a consequence of exposure to high food availability, as both jaw and test growth halt when food is scarce.

Morphological differences between species of the sea bass genus Lateolabrax (Teleostei, Perciformes), with particular emphasis on growth-related changes.

Morphological differences, including growth-related changes, were examined in three morphologically similar East Asian sea bass species, Lateolabraxjaponicus, L.maculatus and L.latus. In many cases, body measurements indicated specific patterns of growth-related proportional changes. Lateolabraxlatus differed from the other two species in having greater body depth, caudal peduncle depth, caudal peduncle anterior depth, snout length, and upper and lower jaw length proportions. In particular, scatter plots for caudal peduncle anterior depth relative to standard length (SL) in that species indicated complete separation from those of the other two species, being a new key character for identification. Comparisons of L.japonicus and L.maculatus revealed considerable proportional differences in many length-measured characters, including fin lengths (first and second dorsal, caudal and pelvic), snout length, post-orbital preopercular width (POPW) and post-orbital length. In particular, snout length (SNL) and POPW proportions of the former were greater and smaller for specimens >200 and ≤ 200 mm SL, respectively. Because the scatter plots of these proportions for the two species did not overlap each other in either size range, identification of the species was possible using a combination of the two characters. In addition, scatter plots of the POPW / SNL proportion (%) of L.japonicus and L.maculatus were almost completely separated throughout the entire size range examined (border level 90%), a further aid to identification. The numbers of pored lateral line scales and scales above the lateral line tended to increase and decrease with growth, respectively, in L.japonicus, whereas scales below the lateral line and gill raker numbers tended to increase with growth in L.maculatus. Because the ranges of these meristic characters may therefore vary with specimen size, they are unsuitable for use as key characters. Accordingly, a new key is proposed for the genus Lateolabrax.

Superficial, suprahyoid, and infrahyoid neck musculature in naked mole-rats (Heterocephalus glaber): Relative size and potential contributions to independent movement of the lower incisors.

Naked mole-rats (Heterocephalus glaber) are fossorial, eusocial rodents that exhibit the unusual capability of moving their lower incisors independently in lateral and rostroventral directions. The evolution of this trait would presumably also involve concurrent alterations in neck musculature to support and control movements of the lower incisors. In order to assess morphological adaptations that might facilitate these movements, we performed detailed dissections of the neck musculature of adult naked mole-rats. In addition to characterizing attachment sites of superficial, suprahyoid, and infrahyoid musculature, we also quantified muscle mass and mandibular features thought to be associated with gape (condyle height, condyle length, and jaw length). Based on muscle attachment sites, the platysma myoides may contribute to lateral movement of the lower incisor and hemi-mandible in naked mole-rats. The large digastric muscle is likely to be a main contributor to rostroventral movement of each lower incisor. The geniohyoid and mylohyoid muscles also likely contribute to rostroventral movements of the lower incisors, and the mylohyoid may also produce lateral spreading of the hemi-mandibles. The transverse mandibular (intermandibularis) muscle likely serves to reposition the lower incisors back to a midline orientation following a movement.

The subterranean Aenigmachanna gollum, a new genus and species of snakehead (Teleostei: Channidae) from Kerala, South India.

Aenigmachanna gollum, new genus and species, is described from Kerala, South India. It is the first subterranean species of the family Channidae. It has numerous derived and unique characters, separating it from both the Asian Channa Scopoli and the African Parachanna Teugels Daget. Uniquely among channids, A. gollum has a very slender (maximum body depth only 11.1-11.3% SL), eel-like body (head length 20.8-21.6% SL), large mouth (jaw length 60.4-61.1 % HL), 43-44 anal-fin rays, 83-85 scales in a lateral series, an unusual colour pattern and it lacks pored lateral-line scales on the body and body buoyancy. In addition, it is distinguished by its DNA barcode sequence, which is 15.8-24.2% divergent from other species of the family Channidae. Morphological modifications usually associated with a subterranean life, such as reduction of eyes and enhancement of non-visual senses (taste, smell, mechanosensory systems) are absent in A. gollum. However, it shares with subterranean fishes a slight reduction of its pigmentation in comparison to epigean channids.

Adaptive downsizing in the piscivorous cyprinid fish, Opsariichthys uncirostris, facilitates rapid establishment after introduction to a small-scale habitat in Japan

The three-lips (Opsariichthys uncirostris) is a piscivorous cyprinid fish native to the Biwa Lake, central Japan. A recent unintentional introduction of the species has led to its invasion of a novel, small-scale habitat (the Futatsu River) composed of a few riverine stretches connected by irrigation ditches. Comparative observations of fish samples from both habitats provide evidence of disparities in the fish’s size at maturity between the two habitats, with fish in the Futatsu River reaching maturity at smaller body sizes. Achieving a large body size at maturation requires a larger habitat offering a sufficient supply of food. Principle component analysis of body-surface morphometric characteristics revealed that the two populations show differences in both their body shape and growth rates. In the Futatsu River, the growth rates of upper jaw length, lower jaw length, eye diameter, predorsal length, and tail length were accelerated, while the growth rates of head depth, body depth, and tail depth were decelerated, leading to the acquisition of a distinctly slender body. It is plausible that small-scale habitats with less abundant food supplies favor sexual maturation at smaller body sizes and that slender bodies improve swimming performance, thus making such disproportional downsizing a consequence of adaptation to a novel environment. Whether this change is due to phenotypic plasticity or rapid evolution remains unknown.

Meristic and Morphometric Variations of Barred Spiny EEL Macrognathus pancalus Populations from Bangladeshi Freshwaters: An Insight Into Landmark-Based Truss Network System

Abstract The present research focuses to examine the meristic and landmark-based morphometric variations of barred spiny eel Macrognathus pancalus from four populations namely Dhakuria beel, Jessore (DBJ); Bohnni boar, Gopalgonj (BBG); the Arial kha river, Madaripur (AKRM) and the Nabaganga river, Jhenidah (NRJ) in Bangladeshi freshwaters. Six meristic counts were compared among four populations and significant differences were observed in number of caudal fin rays and number of pelvic fin rays in all meristic characters. The truss protocol was used in the present study based on six general morphometrics and fifteen truss measurements. Univariate statistics showed that five (standard length (SL), upper jaw length (UJL), lower jaw length (LJL), head depth (HD) and inter orbital (IO)) of six morphometric and eleven truss networks (viz. 2-3, 3-4, 5-6, 6-7, 7-8, 1-8, 2-8, 3-8, 3-7, 4-7 and 5-7) among fifteen truss measurements differed significantly. Cannonical discriminate function analyses were conducted among samples and the populations were fully intermingled. Pooled within-group correlation showed morphometric and landmark measurements; the first discriminant function (DF) accounted for 79%, the second DF accounted for 15.9% and third DF accounted for 5.1% of group variability. An euclidian dendrogram was prepared based on morphometric and truss measurements in four populations, where two clusters were mainly formed, in which first cluster formed by NRJ population was fully separated, and the second cluster was formed by two populations of AKRM and DBJ. Additionally, a subcluster BBG was formed with AKRM. On the basis of morphometric and truss measurements, 68.8%, 83.6%, 55.6% and 80% of original grouped cases were correctly classified in NRJ, AKRM, DBJ and BBG, respectively. These results specify the presence of different stocks of fish from four aquatic habitats. This study is highly significant for proper conservation and effective management of M. pancalus populations as well as for the scientific community for further research.

Masticatory Apparatus Performance and Functional Morphology in the Extremely Large Mice from Gough Island.

Since their arrival approximately 200 years ago, the house mice (Mus musculus) on Gough Island (GI) rapidly increased in size to become the largest wild house mice on record. Along with this extreme increase in body size, GI mice adopted a predatory diet, consuming significant quantities of seabird chicks and eggs. We studied this natural experiment to determine how evolution of extreme size and a novel diet impacted masticatory apparatus performance and functional morphology in these mice. We measured maximum bite force and jaw opening (i.e., gape) along with several musculoskeletal dimensions functionally linked to these performance measurements to test the hypotheses that GI mice evolved larger bite forces and jaw gapes as part of their extreme increase in size and/or novel diet. GI mice can bite more forcefully and open their jaws wider than a representative mainland strain of house mice. Similarly, GI mice have musculoskeletal features of the masticatory apparatus that are absolutely larger than WSB mice. However, when considered relative to body size or jaw length, as a relevant mechanical standard, GI mice show reduced performance, suggesting a size-related decrease in these abilities. Correspondingly, most musculoskeletal features are not relatively larger in GI mice. Incisor biting leverage and condylar dimensions are exceptions, suggesting relative increases in biting efficiency and condylar rotation in GI mice. Based on these results, we hypothesize that evolutionary enhancements in masticatory performance are correlated with the extreme increase in body size and associated musculoskeletal phenotypes in Gough Island mice. Anat Rec, 2019. © 2018 American Association for Anatomy.

Evolution of Sexual Dimorphism in Tube Blennies (Teleostei: Chaenopsidae).

SynopsisThe study of sexual differences provides insights into selective factors operating on males and females, especially for clades exhibiting varied levels of dimorphism. Sexual differences in morphology and coloration (melanophores) were compiled for 66 of the 89 species of tube blennies (Blenniiformes, Chaenopsidae) from the systematic literature and examination of preserved specimens. Chaenopsids include essentially monomorphic species and those in which males and females differ in as many as 17 morphological and 14 coloration features. While the sexes of most species differ in coloration (at least at the time of breeding), they are morphologically similar in Acanthemblemaria, Hemiemblemaria, and Lucayablennius. While other genera exhibit an intermediate level of dimorphism, species of Coralliozetus, Cirriemblemaria, and Emblemaria are dramatically dimorphic. Character maps on a phylogenetic hypothesis indicate that this extreme level of dimorphism evolved independently in these genera. A complex history of evolution is implied by examination of jaw length with both increases and decreases in one or both sexes leading to either dimorphism or monomorphism. Several features related to shelter defense are monomorphic in species where both sexes inhabit shelters, but dimorphic where only males occupy shelters. Other dimorphic features increase the conspicuousness of male courtship and aggressive displays.

Regression models of individual cephalometric indicators used in the method of E.P. Harvold

Many scientific studies have shown the superiority of the Harvold method when performing linear measurements for both the upper and lower jaw. The purpose of the work is to construct and analyze the regression models of teleroentgenographic indices used in the method of E.P. Harvold young men and women with normal occlusion close to orthognathic bite and harmonic face. The analysis of lateral teleroentgenograms of 38 young men (aged from 17 to 21) and 55 young women (aged from 16 to 20 years) with normal occlusion close to orthognathic bite and harmonic face, obtained using the Veraviewepocs 3D device, Morita (Japan), was performed according to the techniques of R.M. Ricketts, C.J. Burstone, E.P. Harvold. In the course of the study, all the indicators of the above methods, were divided into three groups: 1 – metric characteristics of the skull, which usually do not change during surgical and orthodontic treatment; 2 – indicators of the tooth-jaw system that allow people with already formed bone skeleton to change the width, length, angles and position of the bones of the upper and lower jaws; 3 – indicators that characterize the position of each individual tooth relative to each other, to the bony cranial structures and face profile. In the licensed package “Statistica 6.0”, regression models were constructed for the following parameters included in the second group, depending on the parameters of the first group: ANS-Сond (maxillary length in the Harvold method described as TM-ANS), Pog-Cond (mandibular length in the E.P. Harvold method is indicated as TM-PGN), Max-Mand – (difference in jaw lengths); as well as the index included in the third group, depending on the indicators of the first and second groups – Ap1uAp1l-DOP (angle Ap1uAp1l-DOP). In the young men, all three possible reliable models of teleroentgenographic parameters were constructed using the E.P. Harvold method, which were included in the second group, depending on the indicators of the first group (R2 = from 0.616 to 0.940), and in young women only the length of the upper and lower jaws (R2=0.857 and 0.792). In both young men and women, all models of the second group of models built according to the indicators of the first group included the distance P-PTV. Up to two models for young men and one model for young women included the distance Pt-N. Also, one model for young men and women included the angle of the cranial tilt (POr-NBa). Only young women have models for the front length of the skull base (N-CC). As for young men and women, we also built a reliable model of the third group indicator, depending on the indicators of the first and second groups (the angle Ap1uAp1l-DOP) (respectively, R2=0.626 and R2=0.584). And in young men and women, the size of the distance A-B is included to the constructed regression equations. In addition, in young men, the regression equation includes the value of the distance P-PTV; while in young women - the angles of the ANS-Xi-PM, MeGo-NPog and N-CF-A, as well as the difference in jaw lengths Max-Mand.

Using craniofacial characteristics to predict optimum airway pressure in obstructive sleep apnea treatment

IntroductionManual titration is the gold standard to determinate optimal continuous positive airway pressure, and the prediction of the optimal pressure is important to avoid delays in prescribing a continuous positive airway pressure treatment. ObjectiveTo verify whether anthropometric, polysomnographic, cephalometric, and upper airway clinical assessments can predict the optimal continuous positive airway pressure setting for obstructive sleep apnea patients. MethodsFifty men between 25 and 65 years, with body mass indexes of less than or equal to 35kg/m2 were selected. All patients had baseline polysomnography followed by cephalometric and otolaryngological clinical assessments. On a second night, titration polysomnography was carried out to establish the optimal pressure. ResultsThe average age of the patients was 43±12.3 years, with a mean body mass index of 27.1±3.4kg/m2 and an apnea–hypopnea index of 17.8±10.5 events per hour. Smaller mandibular length (p=0.03), smaller atlas–jaw distance (p=0.03), and the presence of a Mallampati III and IV (p=0.02) were predictors for higher continuous positive airway pressure. The formula for the optimal continuous positive airway pressure was: 17.244−(0.133×jaw length)+(0.969×Mallampati III and IV classification)−(0.926×atlas–jaw distance). ConclusionIn a sample of male patients with mild-to-moderate obstructive sleep apnea, the optimal continuous positive airway pressure was predicted using the mandibular length, atlas–jaw distance and Mallampati classification.

Plectranthias kamii Randll, 1980 (Perciformes: Serranidae) collected from Bitung, North Sulawesi: first record from the Southwest Pacific Ocean

Three specimens of the serranid fish (Serranidae), Plectranthias kamii Randall, 1980 were collected from fish market, Bitung, North Sulawesi on May and June 2010. Some morphological characters P. kamii is closely related to P. sheni, P. megalophthalmus, P. retrofasciatus, P. rubrifasciatus, P. knappi, P. helenae, P. pelicieri, P. jothyi, P. retrofasciatus and P. randalli in sharing of body width, upper jaw length, pelvic spine length and orbit diameter. Meristic count characters of P. kamii differ from P. sheni, P. pilicieri, P. megalophthalmus, P. retrofasciatus and P. rubrifasciatus in having more numerous dorsal spine (18 vs. 15–17) and below lateral line (33–34 vs. 29–33) and differ from P. megalophthalmus and P. rubrifasciatus in having more numerous pored scales in lateral line (13 vs. 14–15) and shorter of anal spine. The present anthiine fish collected from Bitung, Indonesia was described as new record and bringing the total number of species of this genus known in Indonesia to seven.

Three-dimensional study of the upper airway in different skeletal Class II malocclusion patterns.

To characterize upper airway volume and morphology in patients with different skeletal patterns of Class II malocclusion compared to Class I. A total of 197 individuals who had cone-beam computed tomography were allocated into groups according to ANB, SNA, and SNB angles (Class I, Class II maxillary protrusion, Class II mandibular retrusion), each subdivided into hypodivergent, normal, and hyperdivergent. Nasopharynx (NP), oropharynx (OP), and hypopharynx (HP) were assessed with three-dimensional image reconstruction software. Intergroup comparison did not detect significant differences in volume and morphology of NP, OP, and HP. The males displayed larger OP and HP volume than the females. Positive correlations between age and NP, OP, HP volume and between craniocervical angle and OP and HP volume were observed. Linear regression analysis detected a tendency for OP and HP volume to increase as maxillary and mandibular length increased. Upper airway volume and morphology were similar in different skeletal patterns of Class II malocclusion. Actual upper and lower jaw lengths were more closely related to upper airway volume and morphology than the angles that reflected their position relative to the cranial base.