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Form differences between biological structures can be evaluated using several approaches. When landmark data are available, a recently proposed method (euclidean-distance matrix analysis) seems to be able to differentiate between size and shape differences. This method also localizes those areas which differ most between the two structures. We have applied it to analyze the sexual dimorphism in dental arch form in a sample of 50 men and 45 women. Subjects ranged in age between 20 and 27 years, and had sound dentitions. Fourteen landmarks, corresponding to the centers of gravity (centroids) of the occlusal surfaces of all permanent teeth (right second molar to left second molar), were individualized on the dental casts of subjects. All the possible linear distances between pairs of teeth were computed, thus creating four mean form matrices (one for each arch within sex). Gender differences were tested by using euclidean-distance matrix analysis. No significant differences were demonstrated in the shape of arches, while male arches proved to be slightly bigger than female arches.

Form differences between biological structures can be evaluated using several approaches. A recently proposed method (Euclidean distance matrix analysis; EDMA) seems to be able to differentiate between size and shape differences. Here it has been applied to study the asymmetry of mandibular and maxillary arches in 50 men and 45 women with sound dentitions. The centres of gravity (centroids) of the occlusal surfaces of all permanent teeth (right second molar to left second molar) were individualized on the dental casts of subjects. The form of the right and left maxillary and mandibular hemi-arches was separately assessed by calculating all the possible linear distances between pairs of teeth within arch and side. Side differences were tested by EDMA. In men, the maxillary and the mandibular arches were both symmetrical (i.e. there were no significant differences in size or shape between the left and right hemi-arches). In women, the mandibular arch was symmetrical, but in the maxillary arch the two antimeres had a significantly different shape. No size differences were found between the left and right female hemi-arches.

Pretreatment lateral skull radiographs of 145 patients aged 7 to 20 years are classified according to an ANB-angle reading corrected for the position of the maxilla and rotation of the jaw. The Euclidean distance matrix analysis is applied to compare the overall facial morphology between Classes I and II. This method differentiates between size and shape and localizes those areas that differ the most. Statistically significant different facial morphologies were demonstrated in the 32 patients aged 15 years or more. The younger patients with skeletal Classes I and II did not possess these different morphological characteristics. The results show that standard cephalometric classification criteria do not always correlate to actual differences in the overall facial morphology.

The position and asymmetry of all permanent teeth (right second molar to left second molar) were studied in 50 men and 45 women aged 20 to 27 years with sound dentitions. The centers of gravity of the occlusal surfaces of teeth were individualized on dental casts. The maxillary arch distances between homologous teeth were all larger than the mandibular arch distances regardless of gender. Arches in women were found to be significantly smaller than arches in men. On average, arches were symmetric with mean indexes ranging from 0.28% to 4.57%. Results demonstrated that a certain degree of morphological asymmetry may be considered a normal finding.

A model of human neonatal ovary is presented, derived from morphometric, evaluations carried out on left ovaries removed from five full-term neonates with a 46, XX karyotype, free from malformations of the genital apparatus. According to this model, the gonad can be represented by a triaxial ellipsoid with a central medullary core surrounded by a cortical stratum of constant thickness. The germinal population, consisting of follicles and primitive cortical tissue, occupies the cortex, intermingled with the interstitium or stroma. In the cortex it is then possible to describe an outer layer formed by primitive cortical tissue, and an inner portion occupied by follicles. The primary and secondary follicles fill the portion near the medulla and the primordial ones are contained in the middle and outer zones. Since the variability observed among ovaries is slight, we can propose a mean model of neonatal ovary in which the spatial relationships among the different components, the total number of follicles and their position in the cortex can be calculated.

Mandibular border movements were studied in a group of 74 healthy young men and women with sound dentitions and class I molar relationships. Movements were directly performed by the subjects and recorded with a mandibular kinesiograph, and slopes of the first millimeters of motion in the anterior and lateral guidances were calculated. In anterior guidance, the sagittal plane slope was steeper in men than in women, whereas the horizontal plane slope showed no gender differences. In the lateral guidances, frontal plane slopes were steeper in men than in women, with no side differences. The horizontal plane slope presented no side or sex differences. Most of the subjects demonstrated asymmetric guidances for both protrusive and the laterotrusive movements. These findings suggest that criteria for defining the norm should include asymptomatic asymmetry instead of strict morphologic symmetric appearance.

The intrinsic morphology of the mandibular curve of Spee (i.e. independent from reference planes) was studied in 50 men and 45 women with sound dentitions. Left and right curves were reconstructed by a second-order quadratic interpolation of buccal cusp tips. Gender differences were found in both sides, while side differences were found only in the male sample. Male and female curves had similar concavities, but the position of the interpolating second-order quadratic curve relative to the dental arch was significantly different. The right and left male sides showed different concavities, the right-hand side being flatter than the left. Male curves appeared larger than female ones, and the left-hand side was significantly larger than the right regardless of gender. The reported second-order quadratic curves could be used as reference for prosthetic and orthodontic reconstructions.

Mandibular rest position, swallowing occlusal position, and maximum opening were evaluated in a sample of healthy young adults (52 male, 27 female) using a mandibular kinesiograph. It was found that males have a significantly greater vertical dimension of rest than do females, while there were no gender differences in the maximum opening. Most of the subjects had a swallowing occlusal position that coincided with or was very near to the position of maximum intercuspation. Reported data allow the definition of a three-dimensional normal range of variability of maxillomandibular positions during the functional tests most frequently used.

The profiles of 83 healthy young adults were traced from right-side photographs, and then digitized with an image analyzer; each profile thus consisted of a series of coordinates. A dedicated computer program using Fourier analysis resulted in an equation of a curve that interpolated all profile points. By means of cluster analysis, profile equations were divided; two clusters each were found for male and female subjects. A mean profile was calculated for each of the clusters, so that four mean profiles were obtained. These profiles were compared with esthetic parameters found in literature; the results showed that the conventional parameters could sometimes give misleading information for orthodontic and craniofacial orthopedic treatment plans.

The masseter, temporalis anterior and digastric anterior muscles of five volunteers have been investigated by means of surface electromyography. Each muscle was tested by three operators at different times and under three distinct conditions of intermaxillary relationship: resting, with no occlusal contact (physiological rest position); occlusion in centric occlusion (C.O.) without clenching force; and maximum voluntary clench. In all the trials the BIO-PAK system (Bio-Research Associates Inc., Milwaukee, WI, USA) was used. Measurements were made in two consecutive experimental trials separated by an interval of about 15 days. In the first trial the operators had minimal instrumental experience, while in the second trial the same operators had minimal instrumental experience, while in the second trial the same operators had performed at least 30 measurements each. The data have been analysed by a factorial variance analysis, particularly with a view to comparing the variability between operators for each volunteer subject. The analysis revealed statistically significant differences only in the first experimental trial, due to the operators' lack of experience. The study demonstrates that the electromyographic system and protocol used allow good reproducibility of measurements. Furthermore, they have potential applications in both clinics and research.

A morphometric analysis, based on mathematical evaluations and stereological methods, has been used to study five left neonatal ovaries, removed from full-term neonates with a 46,XX karyotype free from malformations of the genital apparatus. Each ovary was completely cut obtaining serial sections and one 1-micron-thick section every 1,000 microns was examined. Ovarian length ranged from 9 to 17 mm (mean 13 mm), width from 3.5 to 7 mm (mean 5.7 mm), thickness from 2.5 to 5 mm (mean 4 mm), and volume from 82.23 to 198.3 mm3 (mean 125.88 mm3). In the ovarian cortex, primitive cortical tissue accounted for 10-20% of the total volume, follicles for 10-25% and interstitium for 35-45%; 10-30% of the organ consisted of inner medulla. The total follicle number ranged from 130,000 to 385,000 per ovary, with an average of 266,000 with 95% being represented by primordial follicles. In all ovaries examined follicular growth was still in process, with follicles at different stages of development.

Pretreatment lateral skull radiographs were studied to analyze the characteristics of facial morphology. Standard cephalometric measurements were compared with those provided by a Fourier description of the overall morphology. Skull patterns were divided into hyperdivergent, neutral, and hypodivergent groups (1) according to the standard thresholds of facial height ratio and (2) according to the mathematical distance between their Fourier coefficients and the Fourier coefficients of three reference plots. Linear regression analysis showed that all the Fourier variables were significantly correlated. The standard thresholds of normality used to classify patients as normal, hyperdivergent, or hypodivergent did not correlate with each other. Fourier analysis resulted in new thresholds of normality that are more accurate than previous norms developed by standard cephalometric measurements. These new thresholds take into account the overall morphologic characteristics of the patient and each separate measurement is strictly correlated with the others.

To study the incidence of calcification of the stylohyoid ligament, 286 orthopantomographs were analyzed. All patients had no symptoms. The total incidence of calcification was noted to be high, at 84.4%. The number and the length of calcifications increased with age, and there was no relationship to sex or mandibular size. The phenomenon is often evident bilaterally. The variety of results reported in the references depends on different criteria in radiographic evaluation and in patient selection.

Mandibular kinesiography measures and records the plot of jaw movements in the three spatial planes; this technique not only offers to investigators information about the dynamics of chewing, but also opens important prospects of quantifying dysfunction. At present, chewing patterns are compared on a qualitative basis only, and their morphologic analysis is not accurate. It is therefore necessary to use suitable mathematical algorithms that can manage the data supplied by modern image analyzers without losing the large amount of information they contain. A mathematical model that, by using a Fourier description of the plots of jaw movements, analyzes and characterizes different chewing classes has been developed. As an example of the possible applications, the variability of the exclusively morphologic aspect of the frontal plane plots of the chewing cycle of some subjects under standard conditions was studied and quantified. A morphologic distance between the Fourier coefficients that characterize each plot and the coefficients of a reference plot was also calculated. On these bases it will be possible to define and measure a "normal" chewing cycle under standard conditions and to make an eventual diagnosis of dysfunctional chewing based on a true morphoquantitative evaluation. Moreover, by deepening the analysis of the more occlusal part of the cycle, the model could aid in the identification of unapparent malocclusions.

The sizes and numbers of subcutaneous adipose-tissue fat cells were determined in obese patients, some of whom had undergone severe weight reduction induced by a jejuno-ileal bypass operation, and others a moderate thinning by a reducing diet, for comparison with those in normals. The size-class distribution of the fat cells suggests a morphoquantitative, dynamic interpretation of the two known forms of obesity, one being of moderate degree and called hypertrophic, the other more severe and called hyperplastic. The hypertrophic obese condition is characterized by a bimodal size-distribution curve of the adipocytes, similar to the curve in normal individuals. In both the normal and the hypertrophic obese, ponderal variations displace this curve forwards or backwards without altering its shape. By contrast, the hyperplastic obese shows a flat size-distribution curve without discernible modes. The smallest size-class of fat cells are the most sensitive to weight-reduction process and hypotrophize so much that they can no longer be recognized as adipocytes in histological sections; thus the size-distribution curve for hyperplastic obese individuals losing weight changes in shape from uniform to bimodal. The relationship which expresses the mean fat cell diameter as a function simultaneously of the initial weight and of ponderal variation was also studied, and tested by multiple regression analysis.

Motor and sensory nerve conduction velocity was determined bilaterally, evry 4 h, in 6 healthy volunteers. A circadian rhythm was demonstrated in 18 nerves out of 24. A rhythm for both motor and sensory groups could also be determined. The two rhythms differ significantly.

A new stereological approach to the study of liver regeneration in the rat is described. The method employs a morphometric model consisting of number and size, as well as surface and volume fractions of hepatocytes, their nuclei, cytoplasm, and their relation to the sinusoidal bed. With this technique, it was found that 8 hr after partial hepatectomy, the number of nuclei increased as did the nucleus/cytoplasm ratio, suggesting an early hyperplastic phase. These data, which have not been reported in other studies, underline the importance of evaluating the complex phenomenon of liver regeneration using a stereological approach, which is more representative of all morphometric changes occurring inside and outside the hepatocyte.

In this relation the authors present preliminary morpho-quantitative data on the fibres of sciatic nerves of normal albino rats, compared with those of animals treated endoperitoneally with 20 and 40 mg of atrazine. This compound (2 chloro - 4 ethylamino - 6 isopropyl amino-S-triazine) is largely used in agriculture, and recently was suspected to be neurotoxic in man. In order to evaluate its action on the peripheral and central nervous systems, and other organs, a morphological, morpho-quantitative and physiological investigation was planned on groups of untreated and treated albino rats. Our data are concerned with both unmyelinated and myelinated fibres. The areas, the shapes (and their distribution spectra), the perimeter and the possible anisothropy (as a sectioning plane index) of unmyelinated axons were evaluated. These parameters were compared in the groups (treated and untreated) by the usual statistical tests. The axonal and total areas, the thickness of the myelin sheath and the number of myelin lamellae of myelinated fibres were analysed, and the related distribution histograms were carried out. A comparison in the three groups was also made in this case. All the data, particularly those resulting from comparison among the groups, are discussed in terms of the possible neurotoxic action of atrazine.

Rectal temperatures were measured automatically every 10 min for part or most of two menstrual cycles in ten clinically healthy young women, 20-30 years of age, with a wearable instrument, the Polychronor. Occasional malfunction of the instrumentation resulted in corresponding gaps in the series. Data were examined by chronograms, plexograms, and chronobiologic serial sections computed with the fit of a 24-hr period, population-mean cosinor, and linear-nonlinear least-squares analyses. Single cosinor-derived circadian parameters were next fitted with a cosine curve of a period equal to the number of days of the corresponding intermenstruum. Second-order infradian inferential statistics were calculated next; the first day of menstruation was used as acrophase reference. A population-mean cosinor at the intermenstrual period yields a temperature acrophase of -279 degrees, with the 95% confidence interval extending from -254 degrees to -312 degrees. Since the intermenstruum differs in different subjects and/or in different menstrual cycles of a given woman, this acrophase corresponds to different time intervals from the first day of menstruation in different cases. This acrophase thus indicates the relative timing within the menstrual cycle of overall high rectal temperatures. On four subjects in four stages of their menstrual cycle, plasma was also obtained at 2-hr intervals around the clock. Ten hormones were determined. The sparse endocrine sampling along the menstrual cycle notwithstanding, a circatrigintan rhythm in all hormones investigated was demonstrated for a woman 26 years of age. At the period corresponding to the intermenstrual interval, the acrophases for T3, cortisol, FSH, testosterone, DHEA-S, T4, and LH occurred before the circatrigintan rectal temperature acrophase, whereas the acrophases for prolactin, estradiol, and progesterone occurred near or shortly after the rectal temperature acrophase. Whereas earlier circatrigintan mapping of adult women had been summarized on a group basis, this study allows individualized circatrigintan rhythm assessment. Circatrigintan, like circadian and circannual, acrophase and amplitude relations do not necessarily imply causal relations, yet they are an indispensable quantitative reference standard for the study of basic mechanisms and for diagnosis and intervention, including endeavors in planned parenthood that might take into account the organism's dynamics with multiple frequencies.

There is strong evidence in the literature for a correlation between the two parts of the red nucleus, magnocellular and parvocellular, and different functions. Unfortunately in the cat, the species most studied both physiologically and anatomically, there are no morphological criteria distinguishing the two portions. With quantitative techniques applied to Nissl preparations the neuronal population of the Red Nucleus has been studied in serial sections along the rostrocaudal axis of the mesencephalon of the cat. Statistical analysis of the data revealed a horizontal plane dividing the two portions of the nucleus with a high statistical significance level. This plane lies between the caudal two-thirds and the rostral third of the nucleus. Although in the model two portions can be distinguished, it is not possible to assign to either a single type of neuron, whether or considered in terms of shape or size.

Circadian rhythmicity of the structural morphometric model of thyroid has been studied in 36 Wistar rats kept in LD 12:12. The parameters evaluated are: a. the volume fraction occupied by: 1. follicle epithelium, 2. colloid, 3. interstitium at 6 time points in 24h; b. the follicle size distribution; c. the number of follicles per unit tissue volume. The circadian rhythms of mean follicular diameter and of follicular cavity mean diameter have been demonstrated (p less than 0.03 and p less than 0.01 respectively) and show overlapping acrophases of -120 degrees (-64 degrees/-176 degrees) and -108 degrees (-99 degrees/-116 degrees). The synchronization between rhythms, shown for mean follicular diameter and for follicular cavity mean diameter, suggests a rhythmical pulsation of the whole follicle, while the thickness of the follicular epithelium does not undergo a statistically significant periodic variation.