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Biomedical subjects

A D'Addona

Publications and source records attributed to A D'Addona.

16 recordsLinked to original sources
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↗
PubMed1993

Electromyographic activity of human masticatory muscles in normal young people. Statistical evaluation of reference values for clinical applications.

Electromyographic activity of anterior temporal and masseter muscles was measured in 92 young healthy men and women with sound dentitions during rest position, contact in centric occlusion and clench. Male and female mean potentials were similar except in clench, where males had higher electromyographic levels. Mean pooled electromyographic potentials were 1.9 microV (TA) and 1.4 microV (MM) during rest position, 6.5 microV (TA) and 2.8 microV (MM) during contact in centric occlusion. Mean maximum voluntary clench potentials were 181.9 microV (TA) and 216.2 microV (MM) in men, 161.7 microV (TA) and 156.8 microV (MM) in women. Examined muscles were more asymmetric at low electromyographic activity (rest and centric occlusion) with the temporal muscle less asymmetrical than the masseter. In females temporal muscle activity tended to dominate at every contraction level, while in males masseter activity was stronger in clench, and temporal activity in centric occlusion and in rest position.

Adult↗
PubMed1993

Position and asymmetry of teeth in untreated dental arches.

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.

Adult↗
PubMed1993

ANB skeletal types correlated to facial morphology: Euclidean distance matrix analysis.

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.

Adolescent↗
PubMed1991

Reproducibility of electromyographic measures: a statistical analysis.

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.

Action Potentials↗
PubMed1991

Cephalometrics and facial shape: new thresholds by an overall approach to classic standards.

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.

Adolescent↗
PubMed1990

Benign cementoblastoma: review of the literature and report of a case at an unusual location.

Benign cementoblastoma is a rare odontogenic tumour localized in the jaws of young people. Benign cementoblastoma has characteristic radiologic and microscopic features and it appears to be fused to the tooth roots. The most important differential diagnosis is-with a benign osteoblastoma. The tumor should be enucleated and the teeth extracted. This case represents only the third reported case of a benign cementoblastoma associated with a third molar.

Diagnosis, Differential↗
PubMed1990

[Bone resorption and cytokines: the role of IL-1 beta, TNF and lymphotoxin].

Tumor necrosis factor (TNF) and interleukin-1 (IL-1) are soluble factors that play a pivotal role in acute and chronic inflammation. TNF is a 17 Kda protein mainly released by monocytes and macrophages and is a common mediator of toxic shock, cachexia and tumor necrosis. IL-1 was first described as a lymphocyte activating factor and it was then discovered that IL-1 has a number of other biological activities and that there are at least two major types of IL-1 (alpha and beta) which bind to the same receptor. Recently it has been shown that TNF and IL-1 beta have an important role in bone resorption.

Bone Resorption↗
PubMed1989

[Dentistry for the elderly patient. 2. Endodontic therapy].

By this contribution the Authors are pointing out that the increase of the average age of the Italian population has led to an increase of demand regarding preservative therapies. It is opportune for the stomatologists to be prepared to the request for services of that kind; in order to be fully qualified they must be aware of many problems that can be coped with, only if one has specific knowledge of the physiopathology of growing old. The dental organ as well is subject to the inexorable senile involution modifying the tissue it is consisting of, and the dentist cannot ignore these problems that are at the basis of the success of any preservative therapy.

Aged↗
PubMed1989

[Irrigant solutions].

After reviewing the various irrigation solutions, indications and chemical properties are described and stress laid on chloroform and chelating agents. Although these are not used as canal irrigants in the strict sense, their special features suggest that they might be included in this group of substances.

Chemical Phenomena↗
PubMedDate not supplied

Statistical evaluation of some mandibular reference positions in normal young people.

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.

Adolescent↗
PubMedDate not supplied

[Hemorrhagic syndromes in the dental patient].

This work considers how, in the field of stomatology, haemorrhagic phenomenous may occur which can even be serious, due to the blood coagulations defects. Only an accurate anamnesis can reveal the pathology and if it is necessary, to undertake to do specific tests and analysis. When the patient is suffered from haemorrhages, it is indispensable to associate with local therapy a general treatment prescribed by the haematologist. We underline the importance of the existence of specialized dental centers for the prevention and the treatment of oral pathologies in patients suffered from blood defects or in patients in anticoagulant therapy which cooperate with specialized haematologic centers. Even in our department, the patients with haemorrhagic diathesis are treated in collaboration with the specialist. We have shown through the presentation of two clinical cases the results who we have reached with the application of our pre-operation protocol.

Adult↗
PubMedDate not supplied

[Orthognathodontic therapy in handicapped patients].

This contribution aims to highlight the importance of orthognathic approach and therapy for the handicapped, with emphasis on the necessity for early intervention to prevent the orthognathic pathology becoming worse. Finally, depending on the condition of the patient, it is advisable to obtain his or her complete collaboration, whenever possible, in order to operate on an outpatient basis, thus avoiding hospitalisation and to give therapy under general anaesthesia.

Cleft Palate↗