Biomedical subjects

V F Ferrario

Publications and source records attributed to V F Ferrario.

At least 19 recordsLinked to original sources

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

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↗

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↗

PubMed1997

The relationship between facial 3-D morphometry and the perception of attractiveness in children.

The aim of this investigation was to determine whether attractive children differ in their three-dimensional facial characteristics from nonattractive children of the same age, race, and sex. The facial characteristics of 36 boys and 44 girls aged 8 to 9 years were investigated. Frontal and profile photographs were analyzed independently by 21 judges, and, for each view, four groups were obtained: attractive boys, nonattractive boys, attractive girls, and nonattractive girls. For each child, the three-dimensional coordinates of 16 standardized soft tissue facial landmarks were automatically collected using an infrared system and used to calculate several three-dimensional angles, linear distances, and linear distance ratios. Mean values were computed in the eight groups, and attractive and nonattractive children were compared within sex and view. Most children received a different esthetic evaluation in the separate frontal and profile assessments; concordance in both attractive and nonattractive groups was only 50%. Moreover, three-dimensional facial morphometry was not able to separate attractive and nonattractive children.

Adult↗

PubMed1996

Occlusion and center of foot pressure variation: is there a relationship?

The influences of head and body posture on the mandibular rest position, the range of functional movements, and the initial tooth contact have been documented. In this investigation, the modifications of the position of the center of foot pressure during natural standing were studied in 30 women. The subjects were divided into three groups: healthy women (control), women with an asymmetric (unilateral) Angle class II malocclusion, and women with temporomandibular disorders. Data were acquired in 30-second trials by use of a force plate that allowed a separate assessment of each foot while the subjects maintained different dental positions: rest position; centric occlusion; maximum clench; occlusion on two cotton rolls placed on the mandibular teeth distal to the canines; and maximum clench on two cotton rolls. Bivariate analysis was used to compute the mean values and relevant variability for the center of foot pressure location during each trial. The results demonstrated that the modifications of foot center of pressure were not influenced by temporomandibular disorders and asymmetric malocclusion or by different dental positions.

Adult↗

PubMed1996

Temporomandibular joint dysfunction and flat lateral guidances: a clinical association.

Temporomandibular joint alterations have been associated with abnormal mandibular movements in the open/close cycles and in the laterotrusive border movements. The quantitative analysis of these movements could allow a better or earlier diagnosis for patients and offer some insight into the pathophysiology of the disorder. Maximum opening and mandibular laterotrusive border movements were studied and measured in a group of 165 patients with a considerable lateral deviation (equal to or greater than 5mm) in maximum opening. Movements were directly performed by the patients and recorded with a mandibular kinesiography. The slope of the lateral guidance (frontal plane projection) was measured in the first millimeters of motion and started from the maximum intercuspal position. On average, slopes were significantly flatter on the same side with the opening deviation. These slopes were significantly flatter than previously published physiologic ranges, whereas contralateral slopes were similar to normal references. The results may be explained by a correlation between the insufficient lateral protection and a temporomandibular mandibular joint dysfunction (ipsilateral low mobility).

Adult↗

PubMed1996

Assessment of facial form modifications in orthodontics: proposal of a modified computerized mesh diagram analysis.

A modified computerized mesh diagram analysis enables rapid, easy, and independent quantifications of facial size, shape, and head position. A lateral cephalometric radiograph is traced, positioned in natural head position (NHP) according to the NHP registered on a lateral photograph, and superimposed by the standard grid of rectangles determined by the patient's upper face height and face depth. The patient's tracing is compared with a reference tracing of a norm. The two tracings are registered at nasion in NHP, and the size difference of the patient's mesh rectangles from the norm is quantified by a size normalization. The shape discrepancies are evaluated by calculating relevant displacement vectors for each cephalometric landmark, and a global difference factor. This computerized method provides a rapid graphic evaluation of the patient's sagittal and vertical discrepancies and can also be applied to determine the effects of orthodontic therapy and/or growth on the skeletal and dental relationships in a single patient.

Adolescent↗

PubMed1996

Facial three-dimensional morphometry.

Three-dimensional facial morphometry was investigated in a sample of 40 men and 40 women, with a new noninvasive computerized method. Subjects ranged in age between 19 and 32 years, had sound dentitions, and no craniocervical disorders. For each subject, 16 cutaneous facial landmarks were automatically collected by a system consisting of two infrared camera coupled device (CCD) cameras, real time hardware for the recognition of markers, and software for the three-dimensional reconstruction of landmarks' x, y, z coordinates. From these landmarks, 15 linear and 10 angular measurements, and four linear distance ratios were computed and averaged for sex. For all angular values, both samples showed a narrow variability and no significant gender differences were demonstrated. Conversely, all the linear measurements were significantly higher in men than in women. The highest intersample variability was observed for the measurements of facial height (prevalent vertical dimension), and the lowest for the measurements of facial depth (prevalent horizontal dimension). The proportions of upper and lower face height relative to the anterior face height showed a significant sex difference. Mean values were in good agreement with literature data collected with traditional methods. The described method allowed the direct and noninvasive calculation of three-dimensional linear and angular measurements that would be usefully applied in clinics as a supplement to the classic x-ray cephalometric analyses.

Adult↗

PubMed1996

Shape of the human corpus callosum in childhood. Elliptic Fourier analysis on midsagittal magnetic resonance scans.

RATIONALE AND OBJECTIVES: The authors previously investigated the midsagittal magnetic resonance images of neurologically intact adults, and analyzed the shape of corpus callosum from a mathematic standpoint. Significant effects of age were demonstrated, without significant sex differences. In the current study, the same mathematic method was applied to analyze the sex and age shape differences of the human corpus callosum in childhood. METHODS: On the midsagittal magnetic resonance images of 84 neurologically intact children (39 boys, 45 girls, aged 4 months to 15 years) the outline of the corpus callosum was identified. Its shape was quantified using elliptic Fourier analysis, which allows for global evaluation of the shape of organs identified by their outlines independently from size, spatial orientation, and relationship to reference planes. Subjects were grouped by sex and age. RESULTS: The shape of the corpus callosum within age and sex classes in childhood was more homogeneous than in adulthood. A significant effect of age was demonstrated by the analysis of variance; however, no significant sex differences were found. CONCLUSIONS: Corpus callosum shape in midsagittal magnetic resonance images was strongly influenced by central nervous system development and aging, but the influence of sex was not sufficient to be detected by current standard magnetic resonance imaging technology, and by the available sample sizes. The current investigation supplies data on the normal callosal shape in the first two decades of life, thus completing previous analysis.

Adolescent↗

PubMed1996

Open-close movements in the human temporomandibular joint: does a pure rotation around the intercondylar hinge axis exist?

Mandibular movements near the maximum intercuspal position were analysed for the location of the mean instantaneous centre of curvature of the interincisal point path. Measurements were performed using a kinesiograph in 28 healthy young adults with sound dentitions and free from temporomandibular joint disorders. The subjects performed habitual open-close cycles at different speeds; opening movements starting from the centric relation occlusion were also analysed. In none of the 28 subjects was the interincisal point path derived from pure rotation movements performed around the intercondylar axis, not even in the first millimetres of motion. Translation and rotation were always combined, and the position of the centre of curvature changed during the motion, showing different characteristics in the open and close movements; these patterns were also dependent upon motion speed. The results show that the hinge axis theory cannot explain the mandibular movements because a pure rotation did not occur around the intercondylar axis.

Adult↗

PubMed1996

Fourier analysis of cephalometric shapes.

Craniofacial growth and development involve both size and shape variations. Shape variations can be assessed independently from size using mathematical methods such as the Fourier series. A method for the reconstruction of outlines starting from selected landmarks and for their Fourier analysis has been developed and applied to analyze the age differences in shape in the tracings of the Bolton standards (lateral view) from 1 to 18 years of age. The size-independent shape of the Bolton standard at 18 years was larger at the chin, at the gonion, and in the anterior cranial base than the shape at 1 year of age. Conversely, the younger shape was larger in the middle part of face, corresponding roughly to the maxillary bone, than the older shape. When standardized for size, growth thus seemed to modify craniofacial shape with progressive lengthening and narrowing. This shape effect was largely overwhelmed by the very evident size increments, and it could be measured only using the proper mathematical methods.

Adolescent↗

PubMed1996

Effect of growth and development on human soft tissue facial shape: a Fourier analysis.

Size plays a distorting role in the estimation of facial morphology, because it can mask more subtle shape differences. The conventional metric approach provides adequate quantitative information about size only, ignoring the problems of shape definition. Mathematical methods, such as the Fourier series, allow a correct quantitative analysis of shape and its changes. Methods to reconstruct outlines, starting from selected landmarks, and to allow Fourier analysis of these outlines have been developed. These techniques were applied to analyze the age and gender variations in shape of the soft tissue facial contour (frontal plane projection) in a group of 144 healthy children, aged 6 to 7 years and 9 to 10 years. The mean contours differed for both size and shape; Fourier analysis corrected for the size discrepancy and separated the contributions of size and shape to the global morphology. In particular, the sine component (asymmetry) of the soft tissue facial contour was influenced by both age and gender.

Cephalometry↗