Static intraspecific allometry of jaws and teeth in Cercopithecus aethiops

Adult static intraspecific allometry of jaw size and tooth area was evaluated in a sample of 100 Cercopithecus aethiops crania (50 male, 50 female). Tooth areas were calculated from mesiodistal and buccolingual measurements of all the teeth in both arcades and were scaled to four viscero-cranial measurements: bimaxillary breadth, maxillo-alveolar length, mandibular length and bigonial width. Allometric coefficients calculated for jaw dimensions alone indicate tighter viscerocranial integration in females than in males. A finding of note was that half of the variation in maxillo-alveolar length may be accounted for by variation in mandibular length: females are isometric, males negatively allometric.
A similar degree of allometric mosaicism was found when maxillary incisor size was scaled to maxillary length and width. In females, the relationship was negatively allometric, whilst incisor size in males was found to be unrelated to either. Negative allometry characterized the relationship of canine base area to jaw length in both sexes, with males additionally being positively allometric to mandibular width.
The scaling of postcanine tooth areas to jaw length was characterized by a dichotomous pattern: males showed significant mandibular integration whilst females showed only significant maxillary integration. Compensatory tooth size interaction between maxillary canine base area and the summed incisor and postcanine areas was suggested by the significant negative allometric relation between them.     

Tooth size and arcadal length correlates in man

Intra-arcadal mesiodistal and buccolingual tooth size correlations were evaluated in a sample of 125 caucasoids with ideal occlusion. Dental dimensions were corrected for arcade mength (as a measure of jaw size) by a series of regression analyses of each mesiodistal dimension on the sum of the mesiodistal dimensions within each arcade. Regression coefficients of tooth dimension on arcade length were calculated to gain an insight into the dimensional sensitivity of individual teeth to arcade length variation. The data presented here suggest a strong association between arcadal length (jaw size) dependence, and the dimensional stability of individual teeth. When corrected for arcade length, a definite pattern of tooth size correlation emerges: postcanine maxillary and mandibular teeth are negatively correlated to the anterior teeth and are positively correlated to one another. The hypothesis is developed that anterior and postcanine teeth should be viewed as two separate and negatively size-correlated units, beyond the boundaries of the four morphological tooth classes. Recognition of this basic dichotomous size arrangement within each jaw allows for a reassessment of some of the problems associated with hominid dental evolution.     

Sexual dimorphism of tooth size in anthropoids

We have examined the size of the canine and postcanine teeth of cebid and catarrhine primates in relation to each other, to jaw size and to body weight. We have found that the canine size of males is large enough to be limited by jaw shape and size. A large contribution of P4 to the postcanine row is associated with smaller canines in males. Neither factor seems to limit canine size in females. The females of a small number of species possess enlarged canines. Much of the variation of the postcanine row can be described by the ratio of the (nominal) crown areas of M1 to M3. This ratio is monomorphic which conforms with the general lack of dietary dimorphism in primates. A brief discussion of the evolution of canine size is offered with a new suggestion to account for canine reduction in male hominids.     

Interspecific and intraspecific relationships between tooth size and jaw size in primates

The association between mandibular robusticity, postcanine megadontia, and canine reduction in hominins has led to speculation that large and robust jaws might be required to spatially accommodate large canine and molar teeth in hominins and other primates. If so, then variations in mandibular form that are generally regarded as biomechanical adaptations to masticatory demands might instead be incidental effects of functional requirements of tooth support. While the association between large teeth and deep, robust jaws in hominins is well known, the relationship between tooth size and jaw size has not been systematically evaluated in a comparative sample of primates. We evaluate the relationships between molar tooth size, canine tooth size, and mandibular corpus and symphyseal dimensions in a sample of adult anthropoids in interspecific (n=84 species) and intraspecific (n=36 species) contexts. For intraspecific comparisons, tooth size and jaw size are correlated, but for a majority of species this is a function of sexual size dimorphism. Interspecific comparisons lend little direct support to the hypothesis that jaw breadth directly covaries with molar tooth breadth, but they do support the hypothesis that mandibular depth is associated with canine tooth size in males. The latter observation suggests that if there is a causal association between canine size and mandibular depth, it is subject to a threshold effect. In contrast, neither corpus nor symphyseal robusticity, measured as a shape index of breadth/height, are correlated with tooth size. Our results suggest that further studies of the relationship between tooth size and corpus morphology should focus on tooth root size and corpus bony architecture, and that species-specific factors should have a strong impact on such relationships.     

Static intraspecific maxillofacial allometry in the chacma baboon

Adult static intraspecific allometry of jaw size and tooth area was evaluated in a sample of 104 Papio ursinus crania (52 male, 52 female). Tooth areas were calculated from mesiodistal and buccolingual measurements of all the teeth in both arcades and were scaled to four viscerocranial measurements: bimaxillary width, maxillo-alveolar length, mandibular length and bigonial width. Craniodental allometric analyses indicate that larger animals will tend to have proportionately shorter and narrower lower jaws. From the log-transformed interspecific analyses between P. ursinus and C. aethiops we conclude that males and females within each species share a common exponential value for jaw length. Hence increased sexual dimorphism for muzzle length in P. ursinus is attributable to increased divergence between the male and female slopes. Post-canine area was found to be significantly correlated to maxillary length and to canine size only in females, with exponential values similar to those reported for the same bivariate regressions in C. aethiops. A hypothesis of nutritional equivalence is advanced to account for these observations. Canine base area and the area of P3 were the only tooth areas that scaled in a positively allometric fashion to jaw size--but only in males. Hence the existence of a canine complex is confirmed in the male Chacma baboon, the size of which is related to jaw length.     

Static intraspecific allometry of the dentition in Otoletnur crassicaudatus

Adult static intraspecific allometry of tooth size was evaluated in a sample of 66 Otolemur crassicaudatus (34 male, 32 female). Tooth areas were calculated from mesiodistal and buccolingual measurements of canines and postcanine teeth of both arcades and were scaled to four viscerocranial measurements: bimaxillary width; maxillo-alveolar length; mandibular length and bigonial width. Individual tooth crown areas were also scaled to total skull length, body length and body weight. From the log-transformed analyses it is concluded that postcanine tooth size was unrelated to body length or weight, and poorly correlated to skull length or jaw size. Although viscerocranial size appears to be independent of body size, these measures are well correlated to skull length. It is shown that the longer the skull, the shorter and narrower the maxilla, and the longer and broader the mandible. Canines are shown to scale negatively allometric to skull length, hence, large animals will have relatively small canines.     

Folivory, frugivory, and postcanine size in the cercopithecoidea revisited

At a given body mass, folivorous colobines have smaller postcanine teeth than frugivorous cercopithecines. This distinction is a notable exception to the general tendency for folivorous primates to have relatively larger postcanine tooth rows than closely related frugivores. The reason for this anomalous pattern is unclear, but one potential explanation is that the difference in facial size between these two subfamilies confounds the comparison-i.e., it may be that the large postcanine teeth of cercopithecines are a consequence of their large faces. The goal of this study was to test this hypothesis. Phylogenetic comparative methods were used to examine the relationships among postcanine area, facial size, and body mass in 29 anthropoid primates, including eight colobines and eight cercopithecines. Results indicate that there is a strong and highly significant partial correlation between postcanine area and facial size when body mass is held constant, which supports the hypothesis that facial size has an important influence on postcanine size. Moreover, colobines have larger postcanine teeth relative to facial size than cercopithecines. Surprisingly, when facial size is held constant, the partial correlation between postcanine area and body mass is weak and nonsignificant. These results suggest that facial size may be more appropriate than body mass for size-adjusting postcanine measurements in some contexts. A phylogenetic comparative test of the association between diet and relative postcanine size (scaled using facial size) confirms that folivorous anthropoids are characterized by relatively large postcanine teeth in comparison to closely related nonfolivores.     

Postcanine tooth size in female primates

The results of many allometric studies of postcanine tooth size in mammals have not corresponded to expectations of tooth size based on energy requirements and dental function. The purpose of this study is to investigate the relationship between postcanine occlusal surface area, body size, and the metabolic demands of pregnancy and lactation in female primates. Tooth and body sizes from 38 primate species were taken from the literature to test two hypotheses: 1) females should have relatively larger teeth than males in order to masticate additional food for the energetic costs of reproduction; 2) taxa with the largest neonatal size (a measure of average metabolic costs of pregnancy and lactation) should have females with a greater degree of relative dental enlargement. The results show that relatively large female teeth are not found consistently in primate species. Females have less occlusal surface area than expected on the basis of the male tooth and body size regression in 21% of the species, and there is no correlation between relative female tooth size and relative newborn size across higher primate taxa. The degree of female dental enlargement is most closely related to degree of sexual dimorphism in body weight. The correlation between degree of body weight dimorphism and relatively larger postcanine teeth in females than in males is 0.87 in the 38 species. Species that are monomorphic in weight tend to be monomorphic in tooth size even though females apparently require more food than males.(ABSTRACT TRUNCATED AT 250 WORDS)     

Estimating age of harbor seals (Phoca vitulina) with incisor teeth and morphometrics

We compared annuli counts from sets of canine, postcanine, and incisor teeth from 450 subsistence-harvested harbor seals, submitted blind to a laboratory. Postcanine and incisor ages were highly correlated with canine age estimates ( r = 0.985 and r = 0.984, respectively), as were postcanine and incisor teeth ( r = 0.984). Age estimates from teeth of 23 known-aged seals were highly correlated; canine teeth r = 0.987; postcanine r = 0.996; incisor r = 0.992, although age for all tooth-types was underestimated for a 29-yr-old seal. Incisor estimates were variable; comparison of age estimates from two incisors/individual ( n = 42) was r = 0.992 if only high-quality age estimates were used and r = 0.705 if lower-quality estimates were used. Morphometrics and incisor-based ages of 164 live-captured seals were explored to derive a method of estimating ages of harbor seals when age estimates are needed immediately; 39 seals were of known age. Curvilinear length, mass, and axial girth were most predictive of age for females, and curvilinear length and mass for males (equations for morphometrically calculating ages are given). Morphometric-based age estimates were highly correlated with known ages ( r = 0.896) and incisor-based estimates ( r = 0.904) and discrepancies between known and morphometric-based ages were small for younger seals. Morphometric-based age estimates also accurately distinguished between young and mature individuals.     

Premaxillary-maxillary suture asymmetry in a juvenile Gorilla. Implications for understanding dentofacial growth and development

A specimen of juvenile gorilla was found that had the premaxillary-maxillary suture coursing between the lateral deciduous incisor and deciduous canine on one side of the jaw, but between the central and lateral deciduous incisors on the other; in the latter, the suture also separates the alveolus of the lateral deciduous incisor from the crypt of the growing successional lateral incisor. Rather than dismiss this exception to the traditional dictum of tooth identification--which is based on the position to teeth relative to this suture--as some inconsequential anomaly, an attempt is made to understand how this can occur within the confines of present understanding of dentofacial growth and development and developmental theory. An hypothesis relating tooth and tooth class identification is presented in the context of ectomesenchymally predifferentiated stem progenitors and subsequent tooth class proliferation.     

Size and shape of the mandibular condyle in primates

The relationships between the size of the articular surface of the mandibular condyle and masticatory muscle size, tooth size, diet, and biomechanical variables associated with mastication were studied by taking 12 measurements on skulls of 253 adult female anthropoid primates, including three to ten specimens from each of 32 species. In regressions of condylar length, width, or area against body weight, logarithmic transformations substantially improve the fit of the equations compared with untransformed data. There is a strong relationship between condylar measurements and body weight, with all correlations being .94 or higher. The slopes of the allometric regressions of length, width, and area of the condylar head indicate slight positive allometry with body size. Folivorous primates have smaller condyles than frugivorous primates, and colobines have smaller condyles than cebids, cercopithecines, or hominoids. When colobines are eliminated, the differences between frugivores and folivores are not significant. However, the two species with the relatively largest condyles are Pongo pygmaeus and Cercocebus torquatus, suggesting that there may be a relationship between unusually large condylar dimensions and the ability to crack hard nuts between the teeth. Cranial features having strong positive correlations with condylar dimensions include facial prognathism, maxillary incisor size, maxillary postcanine area, mandibular ramus breadth, and temporal fossa area. These data are interpreted as indicating that relatively large condyles are associated with relatively large masticatory muscles, relatively inefficient mandibular biomechanics, and a large dentition. These relationships support the growing evidence that the temporomandibular joint is a stress-bearing joint in normal function.     

Tooth crown heights, tooth wear, sexual dimorphism and jaw growth in hominoids

The aim of this review is to bring together data that link tooth morphology with tooth function and tooth growth: We aim to show how the microanatomy of hominoid teeth is providing evidence about rates of tooth growth that are likely to be a consequence of both masticatory strategy and social behaviour. First, we present data about incisor and molar tooth wear in wild short chimpanzees that demonstrate how crown heights are likely to be related to relative tooth use in a broad sense. Following this we review recent studies that describe the microanatomy of hominoid tooth enamel and show how these studies are providing evidence about tooth crown formation times in hominoids, as well as improving estimates for the age at death of certain juvenile fossil hominids. Next, we outline what is known about the mechanisms of tooth growth in the sexually dimorphic canine teeth of chimpanzees and compare these patterns of growth with tooth growth patterns in the canines of three fossil hominids from Laetoli, Tanzania. Finally, we discuss how selection pressures that operate to increase or reduce the size of anterior teeth interact with jaw size. We argue that the space available to grow developing teeth in the mandibles of juvenile hominoids is determined by the growth patterns of the mandibles, which in turn reflect masticatory strategy. The consequences of selection pressure to grow large or small anterior teeth are likely to be reflected in the times at which these teeth are able to emerge into occlusion.     

Relationship between canine dimorphism and mandibular morphology in the hamadryas baboon and the Japanese monkey

To examine morphological interrelationships between canine size and mandibular corpus shape, inter-sex comparisons were made in the hamadryas baboon and the Japanese monkey, known to display extreme and moderate canine dimorphism, respectively. Results of adult comparisons showed that all mandibular dimensions were significantly larger in the males than in the females in both species. In the hamadryas baboon, the males also exhibited a higher ratio of anterior to posterior corpus height than the females. This sex difference in corpus shape was not significant in the Japanese monkey, indicating lack of involvement of canine dimorphism. Analysis of mandibular growth patterns in the hamadryas baboon demonstrated that significant sexual size difference did not occur before incisor eruption, and that the anteriorly high corpus of the adult male mandible was associated with a rapidly increasing symphyseal height after incisor eruption. It was also shown that the female canine started to erupt shortly after incisor eruption, while the forming male canine continued to stay near the mandibular base and developed further in size until eruption. The relative positions of the incisors kept shifting upwards even after eruption in the males, while they hardly changed in the females. It is therefore suggested that the prolonged development and size increase of the male canine is accompanied by further enlargement of the symphysis, resulting in the higher anterior corpus of the adult males compared to the adult females. The results thus indicate the importance of understanding the spatial relationships of the developing teeth in interpreting mandibular morphology.     

Size, shape and structural versatility of the skull of the subterranean rodent Ctenomys (Rodentia, Caviomorpha): functional and morphological analysis

Morphological analysis of the skull of the subterranean rodent Ctenomys , a highly speciose genus which uses both claws and teeth when digging, shows that for a broad range of species size, scaling was associated with both variation and maintenance of shape. Our results show that the angle of incisor procumbency (AIP), a character largely viewed as an adaptation to digging with teeth, is highly variable. We found a non-significant relationship between AIP and basicranial axis (basioccipital + basisphenoid) length, a measure of overall skull size. Accordingly, both small and large Ctenomys species possess either high or low AIP. A significant relationship between AIP and diastema length, given the rostral allometry seen in Ctenomys , suggests that hypermorphosis to a certain extent influences AIP. However, the roots of the incisor are lateral to those of the cheek teeth and their position may thus shift freely. This observation supports the notion that skull structural design, and to a certain extent rostral allometry, underlies variation in AIP. On the other hand, the positive allometry of incisor width and thickness indicates that, in larger species, proportionately powerful incisors are able to resist greater bending forces. We found that the out-lever arm of the jaw adductor muscles scales with positive allometry against basicranial axis length. However, we found an isometric relationship between in- and out-lever arms. In this case, conservation of skull proportions, regardless of variation in size, is a feature possibly related to the maintenance of an effective tooth digging capability. Functional and ecological data are discussed when assessing the implications of size and shape variation in the skull of Ctenomys .  © 2003 The Linnean Society of London. Biological Journal of the Linnean Society , 2003, 78 , 85−96.     

Le Fort I型截骨术定位平面的应用解剖学研究

目的：研究Le Fort I型截骨术与上颌牙根尖的关系,为临床合理制订截骨平面提供解剖学依据。方法：选择上颌牙槽清晰或出土后仍有牙保留的颅骨,在颅骨梨状孔下缘至上颌结节作一连线作为模拟Le Fort I型术式截骨水平,以上颌牙槽缘为标志,用游标卡尺测量每侧上颌各牙的牙槽缘至上述模拟截骨水平的距离及牙槽缘至各牙根尖端的长度,然后计算出上颌各牙根尖至Le Fort I型术式截骨线的距离。结果：上颌各牙相对的牙槽缘至Le FortI型术式截骨线的距离,从中切牙至第二磨牙逐渐缩小,右侧中切牙为21．09±1．53mm,左侧中切牙为20．96±1．64mm,右侧第二磨牙为14．94±1．52mm,左侧第二磨牙为14．95±1．59mm;上颌各牙根尖至Le Fort I型术式截骨水平的距离,从中切牙至第二磨牙也逐渐缩小,而两侧尖牙牙根尖距离Le Fort I型术式截骨线的距离右侧为4．49±1．74mm,左侧为4．69±2．14mm,第二磨牙牙根尖距离Le Fort I型术式截骨线的距离右侧为4．65±1．63mm,左侧为4．49±1．89,两侧尖牙牙根尖和第二磨牙牙根尖至Le Fort I型术式截骨水平的距离均比较接近。结论：上颌各牙根尖至LeFortI型术式截骨线的距离均在4mm以上,根据前牙中尖牙牙根尖的位置和后牙中第二磨牙牙根尖的位置,Le Fort I型术式截骨线水平在13、23（3｜3）根尖及27、27（7｜7）根尖上方4mm以上,按此平面作截骨水平较为安全,不易损伤牙根。     

Modularity in the mammalian dentition: mice and monkeys share a common dental genetic architecture

The concept of modularity provides a useful tool for exploring the relationship between genotype and phenotype. Here, we use quantitative genetics to identify modularity within the mammalian dentition, connecting the genetics of organogenesis to the genetics of population-level variation for a phenotype well represented in the fossil record. We estimated the correlations between dental traits owing to the shared additive effects of genes (pleiotropy) and compared the pleiotropic relationships among homologous traits in two evolutionary distant taxa-mice and baboons. We find that in both mice and baboons, who shared a common ancestor >65 Ma, incisor size variation is genetically independent of molar size variation. Furthermore, baboon premolars show independent genetic variation from incisors, suggesting that a modular genetic architecture separates incisors from these posterior teeth as well. Such genetic independence between modules provides an explanation for the extensive diversity of incisor size variation seen throughout mammalian evolution-variation uncorrelated with equivalent levels of postcanine tooth size variation. The modularity identified here is supported by the odontogenic homeobox code proposed for the patterning of the rodent dentition. The baboon postcanine pattern of incomplete pleiotropy is also consistent with predictions from the morphogenetic field model.     

沟牙田鼠的形态特征及分类地位探讨

沟牙田鼠是分布于中国四川西部和甘肃南部的一种罕见小型啮齿动物,迄今标本收藏甚少,种、属地位存在异议,有人认为应并入田鼠属。我们根据四川九寨沟自然保护区采到的16号不同年龄、性别的沟牙田鼠,就其牙齿形态和成年雄性的阴茎结构与其它田鼠类作了比较,发现其成体和幼体在M³和M₃形态上有很大不同。其他重要区别包括：上门齿宽大;下门齿外露部分很短,下门齿总长仅及下颌长的77％左右,远比其他田鼠小;M齿环呈圆弧形或豆形亦很特殊;成年雄性的阴茎骨近支烧瓶状,远支基部膨大与田鼠类差别很大。结果表明：沟牙田鼠属是有别于田鼠属的有效属。     

The functional morphology of the anterior masticatory apparatus in tree‐gouging marmosets (cebidae,primates)

Although all genera of Callitrichinae feed on tree exudates, marmosets (Callithrix and Cebuella) use specialized anterior teeth to gouge holes in trees and actively stimulate exudate flow. Behavioral studies demonstrate that marmosets use large jaw gapes but do not appear to generate large bite forces (relative to maximal ability) during gouging. Nonetheless, the anterior teeth of marmosets likely experience different loads during gouging compared to nongouging platyrrhines. We use histological data from sectioned teeth, μCTs of jaws and teeth, and in vitro tests of symphyseal strength to compare the anterior masticatory apparatus in Callithrix to nongouging tamarins (Saguinus) and other cebids. We test the hypotheses that (1) marmoset anterior teeth are adapted to accommodate relatively high stresses linked to dissipating gouging forces and (2) the mandibular symphysis does not provide increased load resistance ability compared with closely related nongouging platyrrhines. Differences in decussation between Callithrix and Saguinus are greatest in the anterior teeth, suggesting an increased load resistance ability specifically in incisor and canine enamel of Callithrix. Callithrix lower incisor crowns are labiolingually thicker suggesting increased bending resistance in this plane and improved wedging ability compared with Saguinus. Anterior tooth roots are larger relative to symphyseal bone volume in Callithrix. Anterior tooth root surface areas also are larger in marmosets for their symphyseal volume, but it remains unclear whether this relative increase is an adaptation for dissipating dental stresses versus a growth‐related byproduct of relatively elongated incisors. Finally, simulated jaw loading suggests a reduced ability to withstand external forces in the Callithrix symphysis. The contrast between increased load resistance ability in the anterior dentition versus relatively reduced symphyseal strength (1) suggests a complex loading environment during gouging, (2) highlights the possibility of distinct loading patterns in the anterior teeth versus the symphysis, and (3) points to a potential mosaic pattern of dentofacial adaptations to tree gouging. J. Morphol., 2011. © 2011 Wiley‐Liss, Inc.     

Metrical dental analysis on golden monkey (Rhinopithecus roxellana)

Dental variation in the Chinese golden monkey (Rhinopithecus roxellana) is here evaluated by univariate, bivariate, and multivariate analyses. Allometric analyses indicate that canines and P3s are positively, but other dimensions negatively scaled to mandible and maxilla, and to body size. With the exception of the mesiodistal dimensions of I₁ and M₃, and the buccolingual dimension of P₄, mandibular dental variables show similar scaling relative to body size. Analysis of residuals shows that males have significantly larger canine, P³ and buccolingual dimensions of the postcanine teeth (M² and M³) than females. A significant difference in shape between the sexes is found in the buccolingual dimension of the upper teeth, but not in the mandible. Unlike the situation in some other species, female golden monkeys do not exhibit relatively larger postcanine teeth than males. In fact, the reverse is true, expecially for M²s and M³s. The fact that most of the dental variables show low negative allometry to body size might be related a cold environment that has led to the development of larger body size with reduced energy loss. When the raw data are examined by Discriminant Function Analysis the sexes are clearly distinguishable.     

Eating with a saw for a jaw: Functional morphology of the jaws and tooth‐whorl in Helicoprion davisii

The recent reexamination of a tooth‐whorl fossil of Helicoprion containing intact jaws shows that the symphyseal tooth‐whorl occupies the entire length of Meckel's cartilage. Here, we use the morphology of the jaws and tooth‐whorl to reconstruct the jaw musculature and develop a biomechanical model of the feeding mechanism in these early Permian predators. The jaw muscles may have generated large bite‐forces; however, the mechanics of the jaws and whorl suggest that Helicoprion was better equipped for feeding on soft‐bodied prey. Hard shelled prey would tend to slip anteriorly from the closing jaws due to the curvature of the tooth‐whorl, lack of cuspate teeth on the palatoquadrate (PQ), and resistance of the prey. When feeding on soft‐bodied prey, deformation of the prey traps prey tissue between the two halves of the PQ and the whorl. The curvature of the tooth‐whorl and position of the exposed teeth relative to the jaw joint results in multiple tooth functions from anterior to posterior tooth that aid in feeding on soft‐bodied prey. Posterior teeth cut and push prey deeper into the oral cavity, while middle teeth pierce and cut, and anterior teeth hook and drag more of the prey into the mouth. Furthermore, the anterior‐posterior edges of the teeth facilitate prey cutting with jaw closure and jaw depression. The paths traveled by each tooth during jaw depression are reminiscent of curved pathways used with slashing weaponry such as swords and knifes. Thus, the jaws and tooth‐whorl may have formed a multifunctional tool for capturing, processing, and transporting prey by cyclic opening and closing of the lower jaw in a sawing fashion. J. Morphol. 276:47–64, 2015. © 2014 Wiley Periodicals, Inc.