Biomedical subjects

Chiarella Sforza

Publications and source records attributed to Chiarella Sforza.

47 records · Page 3Linked to original sources

PubMed2002

Three-dimensional analysis of active head and cervical spine range of motion: effect of age in healthy male subjects.

OBJECTIVE: To assess the effect of age on active head-cervical range of motion in healthy men. DESIGN: Three-dimensional cervical motion ranges and patterns were measured in 70 men. BACKGROUND: The effect of age on cervical range of motion is still discussed. METHOD: Twenty adolescent (mean age 16 year), 30 young adult (mean age 23 year), and 20 mid-aged (mean age 37 year) men performed maximal head and cervical spine flexion-extension, lateral bending, and axial rotation. Movements were detected using a digital optoelectronic instrument. Maximum head-cervical spine and thoracic motions were separated. RESULTS: Flexion and extension were larger in the adolescents and young adults (130-132 degrees ) than in the mid-aged men (117 degrees ). Thoracic movement increased as a function of age. Lateral bending was symmetric, associated with head-cervical rotation and extension, and larger in adolescents (85 degrees ) than in young (77 degrees ) and mid-aged adults (79 degrees ). Axial rotation was symmetric, associated with flexion-extension and lateral bending, and similar in the three age groups (respectively, 160 degrees, 155 degrees, 153 degrees ). CONCLUSIONS: Active head-cervical range of motion reduced between 15 and 45 years of age in men. Relevance The present data can be used as a reference for cervical range in motion in men between 15 and 45 years.

Adolescent↗

PubMed2002

Active range of motion of the head and cervical spine: a three-dimensional investigation in healthy young adults.

PURPOSE: To define reference values for head-cervical range of motion (ROM) in healthy young adults, to assess the effect of sex, and to quantify the separate contribution of other body districts. METHODS: Thirty women and 30 men performed maximal head and cervical spine flexion-extension, lateral bending, and axial rotation. Movements were detected using a digital optoelectronic instrument. Maximum head-cervical spine and thoracic motions were separated. RESULTS: Flexion and extension were performed mainly in the sagittal plane. The movement was larger in women (136 degrees) than in men (130 degrees). During flexion, both sexes moved the head-neck and the thorax in the same direction. During extension, men moved only the head-cervical spine, while women moved the two analyzed districts in the opposite directions. Lateral bending was nearly symmetric, associated with head-cervical rotation and extension, and larger in women (91 degrees) than in men (77 degrees). Adjunctive thoracic motion was limited in the sagittal and frontal planes, but larger in the horizontal plane (opposite motions of about 20 degrees). Head-neck rotation was symmetric, and associated with concomitant movements in both the sagittal and frontal planes. It was larger in women (162 degrees) than in men (155 degrees), and performed with limited adjunctive thoracic motions. CONCLUSIONS: The present values can be used as a first group of normative data for head-cervical ROM in young men and women.

Adult↗

PubMed2002

Cephalometric and in vivo measurements of maxillomandibular anteroposterior discrepancies: a preliminary regression study.

One of the aims of the present investigation was to assess three-dimensionally the anteroposterior discrepancy of dental bases using a noninvasive direct procedure. A second aim was to verify the relationship of three-dimensional soft-tissue measurement to the well-established two-dimensional cephalometric assessments of anteroposterior discrepancy. Dental and facial landmarks were directly digitized on 20 orthodontic and maxillofacial surgery patients aged 8 to 26 years using an electromagnetic three-dimensional computerized digitizer. The anteroposterior maxillomandibular discrepancy was measured by calculating the linear distances between the projections of subnasal and sublabial landmarks on the occlusal plane, subnasal and sublabial landmarks on Camper's plane, and insertion of maxillary and mandibular median labial frenula on the occlusal plane. From lateral cephalograms of the same patients, the following measurements were obtained: subspinale point-nasion-supramentale point (ANB) angle; corrected ANB angle that compensates for the position of the maxilla and rotation of the mandible relative to the cranial base; Wits appraisal; MM-Wits, linear distance between the projections of points A and B on the bisector of the palatal plane to mandibular plane angle; and soft-tissue Wits, linear distance between the projections of soft-tissue points A and B on the bisecting occlusal plane. The best two-dimensional vs three-dimensional linear regression (r = 0.91) was found between Wits appraisal and the linear distances between the projections of maxillary and mandibular median labial frenula on the occlusal plane (Wits = -1.05 x 3D measurement - 3.75). The three-dimensional evaluation of the sagittal discrepancy of the jaws directly performed in vivo may allow a more complete analysis of a patient's soft-tissue drape together with the underlying hard-tissue structure.

Adolescent↗

PubMed2002

Three-dimensional assessment of the reliability of a postural face-bow transfer.

STATEMENT OF PROBLEM: Incorrect 3-dimensional orientation of a dental cast may compromise the functional and esthetic result of prosthetic restorations. PURPOSE: This study assessed the reliability of a new method to transfer the 3-dimensional orientation of the occlusal plane with a postural face-bow. MATERIAL AND METHODS: The 3-dimensional position of the occlusal plane in 20 subjects (age 20 to 32 years) with a complete dentition in both arches was assessed with a postural face-bow. An irreversible hydrocolloid impression of the maxillary arch was made for each subject and poured in dental stone. The maxillary arch was mounted in an articulator with use of a postural face-bow. The 3-dimensional position of the occlusal plane was then measured and compared to the values obtained with the use of a previously certified, computerized, noninvasive instrument. This instrument digitizes the coordinates of dental and facial landmarks and then calculates the spatial position of the occlusal plane. For each subject, the direct assessment and the face-bow measurement were compared by calculating the absolute difference of the following: the inclination of the occlusal plane relative to the true vertical, frontal plane projection (angle alpha) and sagittal plane projection (angle beta); intercondylar distance; distance of the center of gravity of the anterior part of the maxillary arch to the midpoint of the intercondylar axis; and the maxillary right canine to right condylion distance. Descriptive statistics of the differences were calculated. RESULTS: The postural face-bow appeared reliable and compared well to the computerized assessment, with mean differences ranging from 2.5 degrees to 3 degrees. CONCLUSION: In the population tested, a postural face-bow reliably reproduced the spatial orientation of the occlusal plane relative to the true horizontal plane. This position was transferred to an articulator with limited errors.

Adult↗

PubMed2002

Relationship between the number of occlusal contacts and masticatory muscle activity in healthy young adults.

The electromyographic (EMG) potentials of left and right masseter and temporalis anterior muscles were recorded in 23 healthy young adults during: 1. a 3-second maximum voluntary clench (MVC) on cotton rolls positioned on the posterior teeth (standardized recording); and 2. a 3-second MVC in intercuspal position. EMG potentials recorded in intercuspal position were standardized as a percentage of the mean potentials of the standardized recording, and the EMG muscle activity was calculated. The number of occlusal contacts in intercuspal position was assessed by using eight microm thick shim stocks. Two groups of subjects with either 1. Less than ten occlusal contacts (11 subjects with "few contacts"); or 2. At least ten occlusal contacts (12 subjects with "many contacts") were selected. The MVC muscle activity in the "few contacts" group was significantly lower than that recorded in the "many contacts" group (p<0.005). In conclusion, the number of occlusal contacts and masticatory muscular function are significantly related, at least in young adults with a sound stomatognathic apparatus.

Adult↗

PubMed2002

Repeatability of mae-geri-keage in traditional karate: a three-dimensional analysis with black-belt karateka.

In karate, performance also depends on a correct body shape, and the repeatability of standardized movements conditions the effectiveness of techniques. The execution of mae-geri-keage (frontal snap kick) was studied in 13 karateka (1st-5th dan). The 3D trajectories of 13 body landmarks were analyzed by an optoelectronic instrument while each karateka performed 10 repetitions of the movement. For each karateka and repetition, the standard deviations of the spatial coordinates x, y, z for each landmark were computed. A total standard deviation of the single participant was also calculated. Two experienced karateka performed with the best repeatability (smaller standard deviation) while executing the studied kick. Generally, the best repeatability was observed in the horizontal plane. The lower variability was observed in hips and head. Ankle and knee of the dominant limb had the worse. The method could detect athletes particularly gifted for the discipline. Moreover, it could help in the identification of those parts of body that do not repeat the movement with the desired precision.

Achievement↗

PubMed2002

Three-dimensional hard tissue palatal size and shape: a 10-year longitudinal evaluation in healthy adults.

A 10-year longitudinal evaluation of the morphology (size and shape) of hard tissue palate was performed in 6 female and 6 male healthy adults (mean age at the second evaluation was 33 years, SD = 2.2). All subjects had a complete permanent dentition, including the second molars, and were free from respiratory problems. Palatal landmarks were digitized with a computerized 3D instrument, and their coordinates were used to derive a mathematical model of palatal form. Palatal shape (size-independent) was assessed by a fourth-grade polynomial in the sagittal and frontal plane projections. Palatal dimensions in the frontal and sagittal planes were computed and compared between the 2 evaluations by paired Student t tests. A great variability was observed, and no significant modifications in size were found (P > .05 for all variables). No variations in shape were observed. Sex had no significant effect for any variable (Student t for independent samples, P > .05). This study showed that in healthy subjects, hard tissue palatal morphology does not seem to change between the third and the fourth decades of life.

Adult↗

PubMed2002

Neuromuscular evaluation of post-orthodontic stability: an experimental protocol.

To prevent relapse after orthodontic treatment, retention is often considered indispensable. Soft tissues are thought to have a significant influence on dental movements. To quantify the influence of masticatory muscles on post-treatment relapse, and in an attempt to avoid unnecessary procedures, 2 male orthodontic patients (13 and 30 years old at debonding) were followed up. The patients completed 2 years of fixed orthodontic treatment and received no post-orthodontic retention. After 1 week and again after 6 months, alginate impressions of dental arches and a surface electromyographic (EMG) assessment of the masseter and temporalis muscles during maximum voluntary clenching were performed. The younger patient received surface EMG monitoring once a month for the first 6 months and at the 1-year follow-up appointment. Arch dimensions and the 3-dimensional inclination of the facial axis of the clinical crown (FACC) were measured using a computerized digitizer. Symmetry in muscular contraction was measured by the percentage overlapping coefficient (POC), and potential lateral displacing components were assessed by the torque coefficient (TC). At the 6-month follow-up, no clinical modifications were observed. Quantitative evaluation assessed that arch dimensions had changed slightly (up to 1 mm). While the adolescent patient had no modifications in FACC inclinations, the 30-year-old patient showed significant alterations (up to 18 degrees). In all examinations of the adolescent patient, POC was higher than 86% and TC was lower than 10%. In the adult, POC was inside the normal range, while all TCs were higher than 10.5%. The larger TC measured in the adult may explain the larger modifications in the 3-dimensional position of his dental crowns. In conclusion, a surface EMG assessment may help in the detection of patients who might need post-orthodontic retention.

Adolescent↗

PubMed2002

Elliptic Fourier analysis of facial profiles during growth and development.

The quantitative analysis of facial soft tissues is of overwhelming importance for orthodontic patients. To assess the normal age-related variations in shape, soft tissue facial profiles were studied in 96 healthy male children 3 to 11 years of age and 16 young men (age 18). Standardized left-side photographs were taken of each subject, and facial profiles were traced between trichion and cervical point. The line joining the 2 landmarks was set as the baseline, and each outline was automatically digitized and mathematically reconstructed by a 30-harmonic elliptic Fourier series expansion. The same soft tissue profile was traced and digitized from the Bolton standards of comparable age. All profiles were standardized to the same area, and shape modifications were quantified by calculating the morphologic distance between the Fourier reconstructions of each facial profile and of (1) the 18-year-old Bolton standard (MD-18) and (2) the age-related Bolton standard. Descriptive statistics were computed for each age class. On average, MD-18 was 7.23 at 3 years of age, increased between 6 and 9 years of age, and decreased hereafter, reaching 6.86 at 18 years of age. Within-group variability peaked at 8 years of age, and was minimal at 6 and 18 years of age. The current soft tissue child profiles seemed different from the profile obtained from the Bolton standards.

Adolescent↗

PubMed2000

A direct in vivo measurement of the three-dimensional orientation of the occlusal plane and of the sagittal discrepancy of the jaws.

The aim of the present investigation was to three dimensionally assess craniofacial relationships in vivo. Specifically, by using a non-invasive direct technique, the following measurements were made: 1) natural head position relative to the ground; 2) orientation of the occlusal plane relative to the subject's intrinsic facial planes; and 3) anteroposterior discrepancy of the dental bases, taking into consideration all the facial hard- and soft-tissue structures. Several dental and soft-tissue facial landmarks were directly digitized from 24 adult healthy volunteers with Angle Class I occlusions by means of an electromagnetic three-dimensional computerized digitizer. In natural head position, the three-dimensional orientation of Camper's, occlusal, and mandibular planes were measured along with the anteroposterior maxillo-mandibular discrepancies. In the frontal plane projection, all the measured planes appeared about horizontal. In the lateral plane projection, on average, Camper's plane deviated from the true horizontal by approximately 18 degrees (in a 'head flexed' direction). The occlusal plane deviated from the same horizontal by about 14 degrees, while the mandibular plane had a steeper inclination (about 30 degrees ); both planes were significantly correlated to Camper's plane. The measurements of anteroposterior jaw discrepancy revealed a wide range of sagittal relationships in the analyzed subjects. The method was found to be repeatable and fast. This direct three-dimensional in vivo assessment of the orientation of occlusal plane relative to the other facial planes could allow for a more comprehensive analysis of maxillo-mandibular sagittal discrepancies.

Journal Article↗

PubMedDate not supplied

Neuromuscular patterns of finger movements during piano playing. Definition of an experimental protocol.

Body movements require the activity of muscles fired by their motor neurons, controlled and coordinated according to central motor patterns modulated by the sensory feedback. The direct analysis of movements and forces produced by muscular activity can provide useful information into anatomical details of difficult observation. For instance, the analysis of movement trajectories can be used to obtain some insight into the underlying neuromuscular processes. Piano playing is a learned ability which links natural hand and finger movements in a complex and well-codified pattern. In the present study, the repeatability of finger movements was assessed in pianists of different experience. Five pianists (two females, 9, 23 years; three males, 24, 39, 70 years; all professionals) played nine two-octave C-major scales at 80, 112 and 160 bpm. The three-dimensional coordinates of their right hand fingers were digitized by a motion analyzer. For each pianist, data from each of the three repetition performed at the same velocity were aligned on the time of onset of the first C keypress (thumb), and a coefficient of superimposition was computed. Significant (analysis of variance, p < 0.001) differences were found between pianists and velocities, with a significant pianist x velocity interaction. The oldest man (a well-known concert player) was the less repeatable (mean superimposition 65.8%, SD 17), the 39-y-old man (a piano teacher) was the most repeatable (mean superimposition 81.4%, SD 8.1). In both of them, the thumb was the most repeatable finger; in the girl, the fifth and fourth fingers scored the best repeatability. The fastest scales were the less repeatable in the 70 and 24-y-old men, and the most repeatable in the 39-y-old man and 23-y-old woman. Even a simple and basic piano exercise can be performed with different movement patterns, without a direct relationship to the pianist experience. Apparently, repeatability was lower in concert pianists than in teachers and learners.

Adult↗