Summary of: A comparative anthropometric study of the position of the mental foramen in three populations.

METHOD: The position of the mental foramen was recorded in relation to the mandibular teeth and anatomical landmarks on the mandible in 76 Chinese, 46 European and 33 Indian skulls of known or calculated age at death. One way analysis of variance (ANOVA) with Tukey's test was used to compare the means of the three groups. RESULTS: The length of Indian mandibles was significantly smaller than that of Chinese (p <0.001) and European (p <0.05), but there was no significant difference between European and Chinese mandibles (p >0.05). The distance from the symphysis menti to the mental foramen was not significant in European and Indian mandibles (p >0.05), though the latter were significantly smaller than the Chinese (p <0.001). The distance from the mental foramen to the posterior border of the ramus of the mandible was significantly larger in Chinese and European skulls compared to that of Indian (p <0.01), there being no significant difference between European and Chinese (p >0.05). There was no significant difference in the relative position of the mental foramen (distance from symphysis menti to the mental foramen divided by the length of the mandible) between the Chinese and Indian mandibles (p >0.05) but there was a significant smaller difference between the European and both Chinese and Indian (p <0.001). The modal position of the foramen in the Chinese was in line with the long axis of the second premolar, while the European and Indian between the first and second premolar. CONCLUSION: The notion that the mental foramen lies between the first and second premolars can no longer be accepted. Population differences occur and preoperative radiographs are mandatory.

Factors affecting the variation in the adult temporomandibular joint of archaeological human populations.

To elucidate factors that may affect the variation in the bony components of temporomandibular joint (TMJ), a preliminary study was conducted on the temporal articular surface of the TMJ of 30 skulls from Iron Age and medieval populations from Lithuania and a mixed Neolithic and Bronze Age population from the Central Elbe-Saale region (CESR). Using three-dimensional (3D) photos of the skulls, length and width measurements of the TMJ were obtained and compared with external skull measurements. Distinct, random variation between the TMJ values from opposite sides of the cranium were identified as fluctuating asymmetry. ANOVA results suggest significant differences in the length of the TMJ between the population of the CESR and the two Lithuanian populations, but not between the two Lithuanian populations. Environmental factors, including geography, may be responsible for the variation in the TMJ form.

Growth pattern of the maxillary sinus in the miniature pig (Sus scrofa).

The biological role of the paranasal sinuses is obscure, can be elucidated through a cross-sectional growth study of the maxillary sinus in miniature pigs. The maxillary sinus area was obtained from lateral cephalograms of left skull halves of 103 female miniature pigs of known ages, from newborn to 24 months. Out of several nonlinear models, the growth of the maxillary sinus was best described with the Gompertz model. The first derivative of the Gompertz curve revealed an increase in the growth rates of the maxillary sinus until 4 months, after which sinus growth slowed down. The eruption of the permanent molars did not seem to have a significant influence on this growth pattern. Furthermore, growth in maxillary sinus size in the miniature pig does not follow growth in skull size closely, which showed the highest growth rates in newborn animals. In addition, a correlation analysis revealed that the relationship between maxillary sinus area and different characteristics of the masticatory apparatus (including linear cranial dimensions, and the dry weight of the masseter and zygomatico-mandibularis muscles) were influenced greatly by skull size. These results suggest that the existence of pneumatic cavities within the mammalian skull is not satisfactorily explained solely by an architectural theory. Epigenetic factors are likely to influence the final shape of the maxillary sinus.

Isometric scaling of maxillary sinus volume in hominoids.

Previous hypotheses of maxillary sinus size evolution have proposed one or more changes in the volume of the structure across hominoid phylogeny. These hypotheses have been used subsequently to support the phylogenetic placement of fossil taxa relative to the living Hominoidea. The null hypothesis, that no change in sinus volume independent of size has occurred in ape evolution, is evaluated here by scaling analysis. Mixed sex samples of adult dry crania for the extant ape genera were examined by computer tomography imaging and the volume of the maxillary sinus was obtained. Sinus volume was then regressed, using both least squares and reduced major axis models, against cranial size variables. The results clearly demonstrate that the null hypothesis of no change in relative sinus volume cannot be rejected; thus, there is no support for hypotheses that maxillary sinus volume, independent of cranial size, has changed in the course of hominoid evolution. This result, in turn, has implications for the phylogenetic placement of fossil taxa and highlights the need for the careful delineation of character states in studies of hominoid systematics.

Influence of craniofacial morphology on primate paranasal pneumatization.

In order to test the hypothesis that variation in the maxillary sinus volume (MSV) of anthropoid primates is related to skull architecture, a mixed sex sample of adult primate crania covering Hominoidea, Cercopithecoidea and Ceboidea was examined using CT scans. MSV was regressed against basicranial length, using reduced major axis analysis. 2 distinct scaling patterns emerged: while a large MSV seems to be a primitive condition of Anthropoidea, it is clearly reduced in Cercopithecoidea. Although some correlations exist between MSV and different indices of the facial skeleton, they are relatively weak and differed among the 3 groups. A full appreciation of epigenetic factors and the relation of the paranasal sinuses to different cranial components is necessary to highlight the biological role of skull pneumatization.

A longitudinal study of the growth pattern of the maxillary sinus in the pig-tailed macaque (Macaca nemestrina).

The ontogeny of sexual dimorphism in maxillary sinus size in a nonhuman primate was studied longitudinally for a period of 8 years in 25 female and 25 male Macaca nemestrina via lateral cephalograms. The maxillary sinus was traced and its area digitized. The growth of female maxillary sinuses was described with a Gompertz model; the best fit to the male data was obtained by the logistic model. Growth curves and confidence intervals revealed that the sinuses grew in a similar fashion for 3-4 years in both sexes. After this, female sinuses achieved a plateau in their development while male sinuses continued to grow. Confidence intervals suggested that size dimorphism appeared at the age of 6.3 years. Lowess regression indicated growth spurts in both sexes. Females experienced an earlier and smaller spurt than males. Sexual dimorphism in maxillary sinus size seems to represent a combination of differences in velocity and length of growth. This study indicates that growth of the maxillary sinus follows closely the growth in body size. Nevertheless, due to the variation in sinus size in Macaca, it is questionable if body size is the main determinant of maxillary sinus size. It is suggested that Macaca, with its wide geographic range and different environments, is an especially appropriate genus to use to test hypotheses about the evolution of skull pneumatization in primates.

Growth pattern of the maxillary sinus in the Japanese macaque (Macaca fuscata): reflections on the structural role of the paranasal sinuses.

To investigate the claim that the primate paranasal sinuses possess not a functional but a structural role associated with the skull architecture (Blaney, 1990), the relationship between the maxillary sinus and the skull architecture was studied ontogenetically in 30 skulls of male and female Japanese macaques (Macaca fuscata). Coronal CT scan series and computerised 3-dimensional images served to evaluate the maxillary sinus. The definitive hemispherical shape of the sinus was already achieved after the completion of the primary dentition. Sinus volume increased with a trend indicating positive allometry. When compared with an ontogenetic data set of orang-utan (Koppe et al. 1995), however, the growth rate of the maxillary sinus of M. fuscata was significantly less. The maxillary sinus both of male and female macaques enlarged according to a common growth pattern. However, no sexual dimorphism could be established for the maxillary sinus size. Although the volume of the right maxillary sinus was normally bigger than that of the left side, the results suggested that asymmetry in maxillary sinus volume is related neither to skull size nor sex. Whereas a correlation analysis showed close relationships between the maxillary sinus volume and external cranial dimensions, the partial correlation coefficients revealed that these relationships were highly influenced by skull size. Although it cannot be ruled out that the paranasal sinuses are to some extent linked to the skull architecture, this study does not support a solely structural role for these air cavities.

The course of the mandibular canal in the growing miniature pig.

Miniature pigs are extensively used as laboratory animals in studies concerning craniofacial growth and adaptation. However, in contrast to the vast amount of literature regarding the overall growth pattern of the pig's mandible, little is known about the internal structures of the mandible such as the mandibular canal. In order to investigate the position of the mandibular canal (MC) and the thickness of its buccal and lingual walls, a cross-sectional study was performed on female miniature pigs MINI-LEWE covering the period from newborn to adult. The position of the MC was analyzed at bony segments that were obtained by cutting the drys mandibles interdentally. At each segment a central point of the MC was defined and its relation to the buccal and lingual margin of the mandible was measured. Located at the lower part of the mandibular corpus, the MC runs in the form of an arch within the sagittal plane in anterior direction, getting enlarged into the form of an ampulla in the molar and premolar region. Whereas during the primary dentition the biggest size of the MC was found behind the third deciduous molar, during the secondary dentition the biggest size of the MC was seen in the region of the first and second permanent molar. With regard the buccolingual aspect, the central point of the MC was found mainly in the center of the mandibular corpus. Between the 2nd and 5th month as well as at the beginning of the 18th month the thickest canal wall existed on the buccal side. In the period of the eruption of the succedaneous teeth, however, the lingual wall was thicker than the buccal wall. Results suggest that the definite course of the MC achieves relatively early in the miniature pig with the completion of the primary dentition. There were no major changes of the position of the MC in the postnatal period suggesting that the age factor has only a minor effect on the location of the MC.

The relationship between the palatal form and the maxillary sinus in orang-utan.

The relationship between the palatal form and the maxillary sinus was studied in 40 skulls of male and female Bornean orangutans (Pongo satyrus borneensis) ontogenetically. Univariate analyses of the measurements of the palate and the maxillary sinus showed that the sexual dimorphism appeared earlier in palatal length than in the maxillary sinus volume. Bivariate statistical analyses, including correlation and linear regression analyses, revealed close relationships between the characteristics of the palate and the maxillary sinus for both the growth period and the adult status. Partial correlation coefficients showed, however, that these relations were highly influenced by the skull size. Except significant correlations between the maxillary sinus width and the palatal volume in the adult status, all partial correlation coefficients were clearly below the Pearson's correlation coefficients. In contrast to the situation in humans, this study suggests that under physiological conditions the influence of the palatal form on the maxillary sinus size in the orang-utan is very small. Alterations of the craniofacial morphology during the evolution of the hominids, such as facial reduction and decrease of the maxillary sinus size, are considered important factors which led to changes of the relations between the palatal form and the maxillary sinus.

Growth pattern of the maxillary sinus in orang-utan based on measurements of CT scans.

The postnatal growth of the maxillary sinus was analyzed in 20 male and 20 female skulls of orang-utan (Pongo satyrus borneensis) in 5 age steps. Coronal CT scans were carried out of all skulls using a computed tomograph Siemens SOMATOM DR. The distances between the CT scans were always 4 mm. The outline of the maxillary sinus was surrounded on the CT scans with a planimeter and then the volumes were calculated. Using a growth model introduced by Fanghänel (1974), growth functions for the volume measurements for male and female animals were calculated separately. The growth curves showed a particular course, which was characterized by a quick rise until the age of 15 years. After the age of 20 years the curves for females orang-utan became gradually flat. At the age of 21 to 23 years the confidence intervals of the growth curves for male and female orang-utan began to drift apart, indicating the appearance of a sexual dimorphism. Using the basicranial length as an indicator of skull size, it becomes evident, that the sexual difference in the maxillary sinus' volume is probably based on the fact, that the maxillary sinus' volume of the male orang-utan increases further on following a common growth pattern.

Course of patients diagnosed as having schizophrenia during first episode occurring under age 18 years.

Of 118 child and adolescent schizophrenic patients (ICD-9: 295.x; mean onset age 16.0 years), 97 (82.2%) could be completely investigated at follow-up (mean interval 7.4 years; mean age 23.1 years). At follow-up 30% of the patients were semi-dependent or dependent, 72% still required psychiatric treatment, 44% were at least moderately impaired with regard to educational/occupational functions and 58% with regard to social functions; 73% had experienced at least one further schizophrenic episode. Comparison with schizophrenia beginning in adulthood showed that the impairment in social function was much greater in the younger group of patients. These results support the belief that schizophrenic psychoses starting in adolescence have a worse outcome than those beginning in adulthood. The most efficient indicators for a worse outcome were long duration of inpatient treatment at first admission, a high number of symptoms and low social competence at discharge.

Investigations on the growth pattern of the maxillary sinus in Japanese human fetuses.

The growth pattern of the maxillary sinus was analyzed using 18 human fetuses of both sexes between 9 and 21 weeks of age postconception. The paraffin embedded specimens were cut in series in the frontal and the transversal plane, respectively. The inner surface of the maxillary sinuses was redrawn and surrounded with a digitizer and then the volumes were calculated. A correlation analysis as well as a simple linear regression analysis between the values of the maxillary sinus, different linear values of the nasal cavity and the crown-rump length (CRL) served to prove possible growth relations. The maxillary sinus' Anlage was already identifiable in the 29.8 mm (CRL) fetus. From this first appearance, the maxillary sinus expands not only in posterior direction but also in anterior direction from 11 weeks onwards. The maxillary sinus volume increased from 0.0008 mm3 at the age of 9 weeks to more than 9 mm3 at the age of 21 weeks. The results of the statistical analysis indicated, that the relationship between the maxillary sinus' Anlage and the nasal cavity were strongly influenced by the body size (CRL). This study suggests, that the growth of the maxillary sinus follows special regularities in the early fetal development.

Morphometric studies on the facial skeleton of humans and pongids based on CT-scans.

The changes of the skull, which we can observe during the anthropogenesis, are reflected especially in the different skull proportions. We carried out metric measurements at the median level on 10 adult skulls each of humans, chimpanzees and gorillas as well as 11 skulls of orangutans. All skulls were scanned with a CT at the median level. We measured the lines and angles of the scans and the means and the standard deviations were calculated. We carried out a correlation analysis to observe the relation of their characteristics. We showed that there is a relation between the length of the skull base and the facial length in all species. From the results of the correlation analysis, we can also conclude that a relation exists between the degree of prognathism and the different length measurements of the facial skeleton. We also found a bending of the facial skeleton in relation to the cranial base towards the ventral side, also known as klinorhynchy, in all observed species. The highest degree of klinorhynchy was found in humans and the lowest in orangutans. We will discuss the different definition of the term klinorhynchy and its importance in the evolution of the hominoids.

On the postnatal growth of the canalis mandibulae in the miniature pig.

The shape and the growth of the canalis mandibulae in female miniature pigs, MINI-LEWE, were analysed in 11 postnatal age steps. The lower jaw halves were cut frontally in a defined position and the heights and widths of the canalis mandibulae were measured. Changes in the shape of the canalis mandibulae in the frontal saw cuts were observed with regard to the dentition. After the eruption of the deciduous teeth there was no further change in shape. Growth curves of the mandibular canal's measures reached a peak during the eruption of the deciduous teeth and the first molar, decreasing significantly afterwards. A close correlation was observed between the measures of canal height and canal width. On the other hand there was only a slight correlation with the external measures of the mandible, which suggests that there are different growth processes.

[Prevalence and follow-up of psychiatric disorders in childhood and adolescence. Results of a prospective epidemiologic longitudinal study from ages 8-18 years]. / Prävalenz und Verlauf psychischer Störungen im Kindes- und Jugendalter. Ergebnisse einer prospektiven epidemiologischen Längsschnittstudie von 8-18 Jahren.

In a prospective longitudinal epidemiological study with assessments at age 8, 13 and 18 the prevalence rate for psychiatric disorders remained constant at about 16%. The sex ratio for severe disorders was male dominated even in adolescence, which was a consequence of the high rate of unsocialized disturbances of conduct in boys. Persistence of psychiatric disorders between age 13 and 18 was about 50%, as had previously been the case between age 8 and 13. One child in four suffered from a psychiatric disorder for at least 10 years. In childhood, conduct disorders had a very poor prognosis and emotional disorders a very good one. In adolescence, the course of disorders depended on an interaction between diagnosis and gender. Boys with unsocialized disturbances and girls with emotional problems had a poor prognosis.

[Study of the degree of pneumatization of the viscerocranium in man and pongidae]. / Untersuchungen zum Pneumatisationsgrad des Viscerocranium beim Menschen und bei den Pongiden.

The volumes of the paranasal sinuses of 41 adult skulls of humans, gorillas, chimpanzees and orangutans, were examined with use of a Computertomograph type SOMATOM DR. The percentage distribution of the volumes of the different paranasal sinuses showed that the maxillary sinus always had the greatest volume. The maxillary sinus of the humans showed the smallest volume percentage in comparison with the pongids. The typical differences between humans and pongids were observed in the ethmoidal cells and the sphenoidal sinus. The ethmoidal cells of the gorilla and the orangutan have to be defined as rudimentary. Those of the humans come to more than 20% of the total volume of the paranasal sinuses of all hominoids. Differing from the humans, the sphenoidal sinus of the pongids pneumatizes almost the whole sphenoid bone. This volume percentage of the pongids is twice as high as that of the humans. In addition, an index was calculated from the volume of the facial skeleton volume and the total volume of the paranasal sinuses and defined as the degree of pneumatization. We found that the gorilla has the highest degree of pneumatization followed by the chimpanzee, the orangutan, and the humans. The lowest degree of pneumatization of the humans may be related to the reduction of the jaws.

[The morphology of the palatine arch of pongids]. / Beitrag zur Morphologie des Gaumengewölbes der Pongiden.

With the help of frontal cuts through casts of skulls of Pongids we demonstrated the postnatal development of the form of the hard palate. The form of the hard palate is similar to a semicircle in the frontal cut. In the Chimpanzee the palatal form in the frontal cut ist not as semicircular as in the other great apes and is similar to the palatal form of humans in the molar region. The differences between Pongo pygmaeus and the african apes consists in the fact, that the palate of the Pongo pygmaeus has a stronger vault in the canine region than the palate of the Gorilla and Chimpanzee.

[Functional morphology of the maxillo-mandibular apparatus in the miniature swine MINI-LEWE. 10. Dentition]. / Funktionelle Morphologie des maxillo-mandibulären Apparates beim Miniaturschwein MINI-LEWE. 10. Zahndurchbruch.

In the miniature pig MINI-LEWE the canines and 3rd incisors are already present at birth. Deciduous dentition is completed by the age of 3 months, and the denture consists of 28 teeth. The "replacement milk teeth" (Stehlin 1899) appear between the age of 6 and 8 months. Eruption of the permanent teeth (44 teeth altogether) is not yet over by the 24th month of life.

[Functional morphology of the maxillo-mandibular apparatus in the miniature swine MINI-LEWE. 11. Discussion of the findings of the metric studies and dentition (conclusion)]. / Funktionelle Morphologie des maxillo-mandibulären Apparates beim Miniaturschwein MINI-LEWE. II. Besprechung der Befunde über metrische Untersuchungen und Zahndurchbruch (Schluss).

The graphs showing the dimensions and angles of the skull and jaw indicate that postnatal development trends are basically uniform. Comparison with the Vietnamese miniature pig shows that the miniature pig MINI-LEWE has a longer skull. Postnatal skull growth is accompanied by a distinct shift in proportions. The sequence of dentition if broadly identical to that of the domestic pig and the Pitmann-Moore miniature pig.

[The functional morphology of the maxillomandibular apparatus of the miniature swine MINI-LEWE. 9. Metric studies of the skull and mandible]. / Funktionelle Morphologie des maxillo-mandibulären Apparates beim Miniaturschwein MINI-LEWE. 9. Metrische Untersuchungen am Schädel und Unterkiefer.

Skull and jaw growth are described mathematically as a dynamic process. Graphs of the growth process show that basically the rate of growth decreases monotonically with increasing age. The maximum rate of growth was recorded at the time of eruption of the deciduous dentition during the first 4 months of life. As expected, the changes in the measured angles were greatest during the first 3 or 4 months after birth.