Biomedical subjects

V F Ferrario

Publications and source records attributed to V F Ferrario.

At least 19 recordsLinked to original sources

PubMed1999

Size and shape of the human first permanent molar: a Fourier analysis of the occlusal and equatorial outlines.

Form can be viewed as a combination of size and shape. Shape refers to the boundary outline independently from its orientation, relation to reference planes, and dimension (or size). Shape and its changes could be quantified by mathematical methods such as the Fourier series. In this investigation, Fourier analysis has been used to quantify the morphologic characteristics (size and shape) of the outline of the occlusal surface and maximum circumference (equator) in 259 normal, healthy human first permanent maxillary and mandibular molars and to assess the effect of sex. Large within-group variability was found in the Fourier coefficients. Both equatorial and occlusal molar areas were on average larger in male than in female homologous teeth, but the difference was statistically significant only for the equatorial areas. The mean ratios between equatorial and occlusal dental areas were independent from arch (maxillary and mandibular), side, or sex. Both equatorial and occlusal outlines of left and right homologous molars within sex and arch were similar, without size and shape differences. Similarly, no sex differences in shape were found in the comparison of homologous teeth. The method used in the present study could supply information about dental shape in both its entirety and local variations. In particular, the method is extremely sensitive to local variations in dental shape, and it could be usefully employed to compare single teeth to a standard.

Adolescent↗

PubMed1999

Three-dimensional dental arch curvature in human adolescents and adults.

The three-dimensional arrangement of dental cusps and incisal edges in human dentitions has been reported to fit the surface of a sphere (the curve of Monson), with a radius of about 4 inches in adults. The objective of the current study was to compare the three-dimensional curvature of the mandibular dental arch in healthy permanent dentitions of young adults and adolescents. The mandibular casts of 50 adults (aged 19 to 22 years) and 20 adolescents (aged 12 to 14 years) with highly selected sound dentitions that were free from temporomandibular joint problems were obtained. The three coordinates of cusp tips excluding the third molars were digitized with a three-dimensional digitizer, and used to derive a spherical model of the curvature of the occlusal surfaces. From the best interpolating sphere, the radii of the left and right curves of Spee (quasi-sagittal plane) and of molar curve of Wilson (frontal plane) were computed. Mandibular arch size (interdental distances) was also calculated. The occlusal curvature of the mandibular arch was not significantly influenced by sex, although a significant effect of age was found (Student t, P <.005). The radii of the overall sphere, right and left curves of Spee, and curve of Wilson in the molar area were about 101 mm in adults, and about 80 mm in adolescents. Arch size was not influenced by either sex or age. The different curvatures of the occlusal plane in adolescents and adults may be explained by a progressive rotation of the major axis of the teeth moving the occlusal plane toward a more buccal position. These dental movements should be performed in a frontal plane on an anteroposterior axis located next to the dental crown.

Adolescent↗

PubMed1999

Morphological variation analysis of the repeatability of soccer offensive schemes.

A landmark-based statistical method, morphological variation analysis, for the quantification of the repeatability in the arrangement of body segments during the execution of sport actions has recently been developed. A two-dimensional shape is produced and its morphology is studied. The method was used to measure the within-team variability of the relative positions of players during the execution of offensive schemes in soccer. Two junior soccer teams of different technical abilities (semi-professional vs. amateur), each playing two standardized offensive schemes of different difficulty (easier: throw-in; more difficult: wing attack) were filmed. Each scheme was repeated 25 (semi-professionals) or 10 (amateurs) times. For each repetition, the position of the players in a single significant frame was analysed using morphological variation analysis. The reproducibility of both schemes was higher among the semi-professionals than among the amateurs (two-way analysis of variance, P<0.005). The repeatability of the players' relative positions was related to the difficulty of the scheme and the technical level of the team. Among the amateurs, the throw-in was more reproducible than the wing attack (Student's t-test, P<0.005). The method not only allows the quantification of collective (team) coordination, but also the separation of the influence of individual players.

Adolescent↗

PubMed1999

Soft-tissue facial morphometry from 6 years to adulthood: a three-dimensional growth study using a new modeling.

A recently introduced three-dimensional computerized system with landmark representation of the soft-tissue facial surface allows noninvasive and fast quantitative study of facial growth. The aims of the present investigation were (1) to quantify growth changes in soft-tissue facial morphology, (2) to evaluate sex differences in growth patterns, and (3) to provide reference data for selected angular and linear measurements that could be of interest for the objective analysis of maxillofacial surgery or orthodontic patients. The three-dimensional coordinates of 22 standardized facial landmarks were automatically collected by automated infrared photogrammetry using the three-dimensional facial morphometry method in a mixed longitudinal and cross-sectional study, in which 2023 examinations were obtained in 1348 healthy nonpatient subjects between 6 years of age and young adulthood. Selected parameters (angles, linear distances, and ratios) were calculated and averaged for age and sex. Male values were compared with female values by means of Student's t test. Within each age group, linear distances were significantly larger in boys than in girls (p < 0.05) with some exceptions coinciding with the earlier female growth spurt, whereas angular measurements did not show a corresponding sexual dimorphism. Linear distances in girls had almost reached adult dimensions in the 12-to-13-year-old age group, whereas in boys a large increase was still to occur. This was most evident in the middle third of the face, where both sexes showed almost the same dimension and amount of growth up to the age of 13, with significant differences afterward, boys being larger than girls. On the contrary, in the lower third of the face, significant differences occurred throughout the whole investigated period, boys being always larger than girls. The male versus female angular comparison reflected the differential timing in attainment of adult proportions. The three-dimensional facial morphometry method allowed the noninvasive evaluation of a large sample of nonpatient subjects, leading to the definition of three-dimensional normative data about facial soft tissues. The method could supplement more invasive radiographic evaluations, allowing frequent examinations of children and adolescents before and during treatment, as well as in the follow-up.

Adolescent↗

PubMed1998

Facial volume changes during normal human growth and development.

BACKGROUND: To describe normal soft tissue growth and development of the human face through volume changes and to assess the presence of sexual dimorphism. METHODS: Facial landmark identifications (2,023) were performed on 1,347 healthy Caucasian children and adolescents, ages 6-18 yr, and young adults, ages 19-32 yr. Three-dimensional coordinates of 22 facial landmarks were collected by automated infrared photogrammetry. Facial volumes and selected linear distances and ratios were calculated and averaged for age and sex. RESULTS: Whereas in females in the 14-15 age group, the face had almost completed its growth relative to the adult group, in males a large increase was still to occur, in general agreement with previous reports on craniofacial growth, which suggested a strong tendency in males for growth to continue for several years beyond that seen in females. The male vs. female comparison reflected the different growth patterns. On average, within each age group volumes were significantly larger in males than in females, with some exceptions in the 11-12 age group, where female growth velocity showed a spurt. Sexual dimorphism in facial volume did not appear in different parts of the face to the same extent: a large part of male facial volume preponderance occurred in the lower third of the face. CONCLUSIONS: From 6 yr of age to adulthood, facial soft tissues increased their volumes by >40%, with different growth patterns in boys and girls.

Adolescent↗

PubMed1998

Foot asymmetry in healthy adults: elliptic fourier analysis of standardized footprints.

The size and shape of paired structures differ in the left and right sides of the body. Shape characteristics should be analyzed separately from size to supply information about the normal variations of human organs. In the present study, the within-subject normal symmetry of footprint shape and size was analyzed from a mathematical standpoint. On the standardized left and right footprints of 46 healthy adults (23 women and 23 men; 19-26 years old), the outline of each foot excluding the toes was identified and its shape was quantified independently from size by the elliptic Fourier analysis. The symmetry in shape was quantified on an intra-subject basis by calculating a morphologic distance D between the mathematical reconstructions of the left and right footprints of each subject. Symmetry in size was assessed by the right-to-left area ratio and found to be very good for all subjects; it ranged from 0.948 to 1.049. The subjects were also grouped by sex, and mean values were calculated. Within-subject symmetry in the footprint shape appeared high, with morphologic distances ranging between 8.94 and 2.66 in men and between 7.15 and 3.09 in women. No consistent associations between footprint symmetry and age, body height and weight, or shoe size were found. On average, women had more symmetric size-standardized footprints than did men (women: mean 4.57, SD 1.14; men: mean 5.46, SD 1.7; p < 0.05). Mean size-independent shapes of male and female left and right footprints were also calculated. Together with the analysis of individual asymmetry, they could be used for the quantitative diagnosis of borderline patients.

Adult↗

PubMed1998

A three-dimensional computerized mesh diagram analysis and its application in soft tissue facial morphometry.

A modified computerized mesh diagram analysis that allows rapid and independent quantifications of soft tissue facial size and shape in the three-dimensional space is presented. Normal references are provided, and the application of the method is also exemplified by the analysis of two maxillofacial surgical patients. The Three-Dimensional Facial Morphometry method has been used for the collection of the x, y, z coordinates of 22 soft tissue landmarks in 50 men and 50 women (all healthy young white adults). The method detects the three-dimensional coordinates of retroreflective, wireless markers positioned on selected facial landmarks with two charge-coupled device cameras, working in the infrared field. The midpoint between the right and left tragus landmarks served as the origin of the coordinate axes, and the landmark coordinates were rotated, setting the intercantheal line horizontal on both the frontal and the horizontal planes, and the Camper's plane inclined at -7.5 degrees on the sagittal plane. A standardized mesh of equidistant horizontal (dimension: half the upper face width), vertical (half the vertical projection of upper face height), and anteroposterior (half the horizontal projection of upper face depth) lines was consequently constructed. The lattice was replicated on the entire face and comprised 84 parallelepipeds. Both male and female reference meshes had a harmonious and symmetric appearance, with gender differences in facial size but not in facial shape. The standard normal reference was superimposed on the patient's tracing, and the global (size plus shape) difference was then evaluated by the calculation of the relevant displacement vectors for each soft tissue landmark. A global difference factor was calculated as the sum of the modules of all the displacement vectors. Consequently, a size normalization was performed, and the shape difference (size-standardized) was then evaluated by the calculation of new relevant displacement vectors for each landmark, as well as a shape--global difference vectors.

Adult↗

PubMed1998

Quantitative analysis of penile ultrasonographic shape during the erectile cycle: a new diagnostic tool for erectile dysfunction? Repeatability of the method and preliminary results.

Penile modifications during erection interest not only penile length and circumference, but also its size and shape. In this investigation, the size and shape repeatability of a single standardized ultrasonographic image of penis during flaccidity and erection was quantified in a group of 19 patients complaining of erectile dysfunction. The penis of each patient was placed in the dorsal position and scanned by a 10 MHz linear ultrasonographic probe at the site of maximal corporeal size: (1) during flaccidity; (2) after an intracorporeal injection of 10 micrograms alprostadil; and (3) after a genital stimulation. Each scan was repeated three times for each patient and printed. On each print the outline of the tunica albuginea was drawn, digitized, and mathematically reconstructed by Fourier series that allow a separate quantification of the size and shape differences. Reliability of the tunica albuginea outline and repeatability of probe positioning were separately assessed within patient and functional phase, and found to be good. The actual examinations of two impotence patients performed using the described method are also given. The shape of the corpora cavernosa may be potentially indicative of the homogeneous function of the tunica albuginea, and it may be of use in patients' follow up.

Adult↗

PubMed1998

Preliminary evaluation of an electromagnetic three-dimensional digitizer in facial anthropometry.

OBJECTIVE: In this investigation, the precision of a commercial three-dimensional digitizer in the detection of facial landmarks in human adults was assessed. METHODS: Fifty landmarks were identified and marked on the faces of five men, on five women, and on a stone cast of the face of one man. For each subject, the three-dimensional coordinates of the landmarks were obtained twice using an electromagnetic three-dimensional digitizer, and the duplicate digitizations were superimposed using common orientations and centers of gravity. Metric differences between homologous landmarks were assessed, and Dahlberg's error was computed. RESULTS: For both men and women, the error was 1.05% of the nasion-midtragion distance, while for the cast, it was 0.9%. When the duplicate digitizations were used to mathematically reconstruct the faces, and several distances, angles, volumes, and surfaces were computed, more than 80% of the measurements had coefficients of variation lower than 1%. CONCLUSIONS: The digitizer can assess the coordinates of facial landmarks with sufficient precision, and reliable measurements can be obtained.

Adult↗

PubMed1998

Quantitative description of the morphology of the human palate by a mathematical equation.

OBJECTIVE: To derive a three-dimensional mathematical description of normal human hard tissue palatal size and shape. METHODS: The maxillary dental casts of 30 adolescents free from respiratory problems, who had a complete (28 teeth) permanent sound dentition with normal occlusion, were studied. The x, y, z coordinates of several standardized palatal and dental landmarks were obtained with a computerized three-dimensional digitizer. Palatal landmarks were used to derive a mathematical equation of palatal shape in the frontal and sagittal planes. Palatal width, length, frontal and sagittal heights, and sagittal slope, as well as dental arch transverse and anteroposterior dimensions, were computed. RESULTS: Neither the size nor the shape of the palate was significantly influenced by gender. Only the intercanine distance was larger (p < .025) in males than in females. CONCLUSIONS: Data collected in the present investigation could represent a first database for the quantitative description of normal human palatal morphology in subjects with a complete permanent dentition.

Adolescent↗

PubMed1998

Reliability of soft tissue references for anteroposterior measurement of dental bases.

The aims of the present investigation were to devise a new anteroposterior measurement of maxillomandibular discrepancies that would consider both hard and soft tissue contributions, and to verify the correlation of this measurement to a well-established linear assessment of anteroposterior discrepancy. On the pretreatment lateral cephalographs of 300 orthodontic patients (162 males, 138 females) aged between 6 and 50 years, the Wits appraisal and a new "soft tissue" Wits appraisal (linear distance between the projections of soft tissue A and B points on the bisecting occlusal plane) were measured. In the analyzed sample, the former was more variable than the latter. The two measurements were significantly correlated to each other without sex- or age-characteristic patterns. From the correlation, reference values for the new measurement were estimated and found to be between -1.9 mm and 5.4 mm for individuals with a normal occlusion. The new measurement could allow a more careful evaluation of the soft tissue drape together with the underlying hard tissue structure.

Adolescent↗

PubMed1997

Statistical evaluation of Monson's sphere in healthy permanent dentitions in man.

The three-dimensional curvature of the mandibular dental arch was studied in 20 men and 20 women with sound dentitions and free from temporomandibular joint problems. The x, y, z coordinates of cusp tips of all but the third molars were obtained with a three-dimensional digitizer, and used to derive a spherical model of the curvature of the occlusal surfaces. From the best interpolating sphere the radii of the left and right curves of Spee (quasi-sagittal plane) and of the canine and molar curves of Wilson (frontal plane) were computed. The occlusal curvature of the mandibular arch was not significantly influenced by gender, even if, on average, all the computed variables were larger in men than women. The radii of the overall sphere, right and left curves of Spee, and curve of Wilson in the molar area were about 105 mm in men, and about 100 mm in women. A relatively large intrasample variability in arch curvature was found. The mean sphere radius in men was very close to the classical value of 4 in, confirming Monson's observations, but the relatively large intrasample variability prevented any definitive determination of a sexual dimorphism in the three- dimensional characteristics of occlusal curvature.

Adult↗

PubMed1997

A size-standardized analysis of soft tissue facial profile during growth.

A method for the quantitative and qualitative analysis of the facial soft tissue profile has been developed and applied to analyze the age differences in lateral cephalograms for the annual Bolton standards from ages 1 to 18 years. To standardize for different facial sizes, profiles were traced in polar coordinates without modifications of facial shape. Most of the soft tissue landmarks showed progressive modifications from birth to 18 years of age. Soft tissue nasion and lower lip had a steep change between 2 and 3 years of life, pronasale between 3 and 5 years of life, A', upper lip, and stomion between 4 and 5 years of life. Hereafter, all these landmarks but N' had several minor modifications progressing toward the adult value. Soft tissue nasion did not modify significantly after 2 years of age. Conversely, changes in the relative positions of B' and Pg' were more scattered in the analyzed period. Age-related size differences were more linear than shape modifications, with gradual increments from 1 to 18 years of age. The method allowed a simple and rapid quantitative evaluation of soft tissue profiles during facial growth. An approximate evaluation of the soft tissue thickness at nose, lips, and chin was also possible. No particular mathematical knowledge was required at any step of the analysis. Results were in good agreement with the well-known patterns of normal growth and development, thus confirming the practical possibilities of the method.

Adolescent↗

PubMed1997

A three-dimensional non-invasive study of head flexion and extension in young non-patient subjects.

Head flexion and extension movements near the natural head position (NHP) were analysed for the location of the mean instantaneous centre of rotation (ICR). Forty-six healthy young adults (30 women and 16 men) with sound dentitions, free from cranio-cervical disorders, performed habitual movements that were automatically detected and measured by an infrared three-dimensional motion analyser. ICR and curvature radius were calculated for each movement and subject. In both extension and flexion, ICR position changed during the motion. The movement was symmetrical in all subjects. No gender or flexion/extension differences were found for both ICR position and relevant curvature radius. On average, ICR relative to NHP soft-tissue nasion was located at about 150% of the soft-tissue nasion-right tragus distance, with an angle of about 220 degrees relative to the true horizontal. Results suggest that head flexion or extension is always performed with a combination of rotation (atlanto-occipital joint) and translation (cervical spine) even in the first degrees of motion. Moreover, NHP at rest seems to be some degree more flexed and anterior than head position during movements. These relative positions and their muscular determinants could also influence mandibular posture at rest and during functional movements.

Adult↗

PubMed1997

Effect of growth and development on cephalometric shapes in orthodontic patients: a Fourier analysis.

The age- and gender-related shape variations of the craniofacial skeleton in skeletal Class I children were quantified using a Fourier analysis on the pre-treatment lateral head films of 122 orthodontic patients (age range 7-15 years), who were subdivided into six groups for sex and age (2-year intervals). Seven landmarks representative of the maxillo-mandibular sagittal and vertical relationship were identified and digitized. The contiguous landmarks were connected by segments, the form was normalized with respect to its orientation and size, and a Fourier analysis of the contour was performed. Mean values of the cosine and sine coefficients of the first six harmonics in the sex and age classes were computed. The size-standardized outlines of the oldest boys were narrower and longer than the outlines of the youngest boys (differences at gonion, menton, sella and nasion). Shape differences between mean plots in girls were negligible. In the youngest patients, girls had a larger size-independent shape in the mandibular region; their shape was narrower (anterior-posterior direction) and longer (vertical direction) than male shape. In the oldest patients, boys had a larger size-independent shape at gonion, and a narrower shape at articulare and pogonion than girls. Size increased from the youngest to the oldest boys; size differences were not conspicuous in girls. Within an age class, male size was always larger than female. Fourier analysis allowed a global evaluation of the cephalometric forms, with separate quantifications of the age- and gender-related differences in size and shape.

Adolescent↗

PubMed1997

Asymmetry of normal mandibular condylar shape.

Morphological studies of the facial skeleton in human beings are usually made from radiographs (frontal and lateral projections and orthopantomographs). The conventional linear and angular measurements provide quantitative information only about size, and fail to define the shape and form of the skeletal features and their variations. Mathematical methods such as the Fourier series allow a correct quantitative analysis of the shape and its variations. The outlines of the mandibular condyles in the orthopantomographs of 20 men and 20 women (mean age 29 years) were traced and digitized. All subjects had a good dentition, no temporomandibular joint problems, and were referred to a dental surgery for periodontal problems. A Fourier analysis of the outlines was performed. Fourier coefficients and reconstructed outlines were compared to analyze the condylar symmetry of shape on an intra- and intersubject basis. A significant condylar asymmetry for shape as distinct from size was found on an intrasubject basis, i.e. the left and right condyles of a single individual had a different shape with a large interindividual variability. Conversely, the mean condyle shape of the male and female groups was symmetric.

Adolescent↗

PubMed1997

Three-dimensional study of growth and development of the nose.

OBJECTIVE: The aim of this study was to describe normal nasal growth in a large sample of boys and girls from 6 to 14 years of age, to compare nasal development at 14 years of age with its adult dimensions, and to evaluate differences in growth patterns between males and females. DESIGN: Growth and development of the nose were analyzed through the three-dimensional facial morphometry method. One thousand thirteen examinations were performed on 402 children between 6 and 14 years of age and on 101 adults. Three-dimensional coordinates of five nasal landmarks were collected. Eleven parameters including nasal volume and external surface were calculated and averaged for age and sex. RESULTS: Volume, surface, and linear distances were larger in males than in females, with the exception of the 11-to-12 age group, where a sharp female growth spurt was present. In males, the growth spurt was broader, and continued to 13 years of age at a nearly steady rate. Statistically significant gender differences could be found both in the adult group and before the adolescent growth spurt. CONCLUSIONS: Our findings are in general agreement with previous reports on craniofacial growth, which suggested a strong tendency in males for growth to continue for several years beyond that seen in females.

Adolescent↗

PubMed1997

Size and shape of soft-tissue facial profile: effects of age, gender, and skeletal class.

OBJECTIVE: A method for the quantitative and qualitative analysis of the facial soft-tissue profile has been developed, and applied to analyze the pretreatment lateral head films of 240 orthodontic patients aged 8 to 14 years. METHODS: Patients were subdivided for sex, age, and skeletal class. To standardize for different facial sizes, soft-tissue profiles from nasion to pogonion were traced in polar coordinates without modifications of facial shape, and standardized for an equal skeletal vertical dimension. RESULTS: The method allowed a simple and rapid quantitative evaluation of soft-tissue profiles during facial growth. An approximate evaluation of the soft-tissue thickness at nose, lips, and chin was also possible. No particular mathematical knowledge was required at any step of the analysis. CONCLUSIONS: Facial soft-tissue size and shape were influenced by age and sex, and to a minor extent by skeletal class.

Adolescent↗