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Biomedical subjects

M C Madeira

Publications and source records attributed to M C Madeira.

At least 37 records · Page 2Linked to original sources
PubMed1977

Split-line patterns of the mandible following masseterectomy in adult and growing monkeys.

Architectural changes of the mandibular ramus following masseterectomy were analyzed by means of the split-line technique in both adult and growing monkeys. The right masseter muscle was resected in ten tufted capuchin monkeys (Cebus apella) and they were sacrificed following a 12-month period. Along with modifications in the shape of the mandible, the masseterectomy induced structural changes as revealed by alterations in the split-line patterns. These changes were much more evident in the adult animals. In growing monkeys, intrinsic forces determine an architecture of mandibular growth, represented by the direction of the splits. This is not influenced by the lack of mechanical factors like muscle action. Conversely, the final fibrous architecture of the bone in the adult monkey may be modified by extrinsic mechanical factors.

Age Factors↗
PubMed1977

[The clivus-sphenoidale angle in children (postnatal flexion of the cranial base)].

The clivus-sphenoidale angle of Landzert expresses the flexion of the cranial base in sagittal direction. In previous studies the same authors verified that the clivus-sphenoidale does not change between the 4th and 9th month of fetal life, with an average value of 127.58 degrees, and that in the adult the angle measures 113.95 degrees. To analyse the variations of the opening of this angle in an age span intermediary to those studied before, 89 human skulls were used belonging to both sexes and varying in age from 2 months extrauterine life to 8 years. The angle was traced and measured upon lateral X-rays taken from all skulls. The distribution of average values according to age is found in tables 1 and 2. For statistical evaluation of data, regression analysis and comparison of averages were used. At hand of the results, it is possible to conclude that: 1) there is a significant reduction of the clivus-sphenoidale angle after birth, that is, from 2 months extrauterine life to 18 months. 2) There is no difference in the average values of the angle between 2 and 8 years of age. 3) Growth of the brain and upright posture seem to be the factors most responsible for the post-natal flexion of the cranial base. 4) The angles show great individual differences in all age groups studied.

Age Factors↗
PubMed1976

Direction of the mental canal in human mandibles.

The direction of the mental canal was calculated in the horizontal and vertical planes with a view to aiding anaesthetic techniques. Based on our data, it is advisable to give the following approximate inclinations to the needle when penetrating the mental canal in anaesthetic procedures: 55 degrees postero-anteriorly in relation to a horizontal plane and 40 degrees latero-medially in relation to a horizontal line tangent to the body of the mandible at the level of the mental foramen.

Adult↗
PubMed1975

Anatomical data on the intracranial venous drainage of the tufted capuchin, Cebus apella Linnaeus, 1758.

The venous channels responsible for the intracranial drainage were dissected in a series of 25 male and female adult tufted or brown capuchin monkeys (Cebus apella). It was found that Cebus have a venous arrangement fundamentally the same as in man, differing only in that: 1. the monkey has no inferior sagittal sinus, spenoparietal sinus, and emissary parietal and condylar veins; 2. the occipital sinus is not in connection with other sinuses; 3. there are a spenopetrosal sinus, a petrosquamous sinus, and an unpaired inferior cerebellar vein; 4. besides the internal jugular vein, there is additional intracranial drainage through the petrosquamous sinus and the postglenoid vein; 5. the superficial middle cerebral vein opens into the petrosquamous sinus; 6. the lingual and facial veins are not tributaries of the internal jugular vein; 7. there is a bilateral uniform division of the superior sagittal sinus at the confluence of the sinuses to drain equally into both transverse sinuses; 8. the vascular pattern appears to be quite stable; anatomical variations appear to be few and unimportant.

Animals↗