Hilel Nathan

Mental Foramen and Mental Nerve: Changes with Age

In a study of 525 dry mandibles and dissections in 50 cadavers, the mental foramen (MF) was found: single in 94.67% of the cases and multiple in 5.33%. Its shape was round in 34.48% with an average diameter of 1.68 mm and oval in 65.52% with an average long diameter of 2.37 mm. In 43.66% the MF was located in front of the apex of the root of the second premolar. In children before tooth eruption, the MF is somewhat closer to the alveolar margin; during the eruption period, the MF descends to half way between the margins, and in adults with the teeth preserved, the MF is somewhat closer to the inferior border. With loss of teeth and bone resorption the MF moves upwards closer to the alveolar border. In extreme cases of resorption the MF and the adjacent part of the mandibular canal are open at the alveolar margin. In the dissections the findings were similar. The mental nerve emerged from the MF closer to or at the alveolar border, according to the degree of resorption. In extreme degrees of resorption, the mental nerve and the final part of the inferior alveolar nerve were found directly under the gums. In these cases, the vestibular grooves became very shallow, and the mucosa passed directly from the cheeks over the alveolar ridge. Practical implications of the changes of the MF and mental nerve are discussed.

Some Observations on the Posterior and Lateral Bridge of the Atlas

Six hundred and seventy-two atlas vertebrae of 6 population groups were examined for the presence of a posterior and/or lateral bridge. Of these, 174 (25.9%) presented with partial posterior bridge formation and 53 (7.9%) with a complete bridge. Twenty-six (3.8%) showed some form of lateral bridging. Although controversy exists as to the origin of atlas bridging, the findings of the present study show that aging could be a factor predisposing to complete bridge formation. The clinical significance of bridge formation is discussed with reference to their possible effect on normal vertebral artery function, particularly in rotation.

Jewish populations of the world: genetic likeness and differences

In six Jewish populations from Eastern, Central and Southern Europe, the Middle East, North Africa and Yemen, the frequencies of 30 genes from 13 loci were determined. The calculation of genetic distances between these populations as well as a cluster analysis were done. The gene frequencies of these six populations were computed together with those of 19 other Jewish populations of diverse countries described in the literature. Of the 19 populations, 22 alleles from 10 loci were checked. Gene frequencies in autochthonous, non-Jewish populations from these countries were also computed. All Jewish populations except Yemenites are concentrated in the same cluster, being closer one to another than to any of the non-Jewish groups. A similar picture is obtained when Jewish and non-Jewish populations from 19 countries are subjected to cluster analysis. The differences between the Jewish populations generally tend to bring them closer to the corresponding non-Jewish groups. The present data suggest that these differences cannot always be explained by admixture; other factors such as the effect of convergent adaptive processes must be considered.

Sublingual gland herniation through the mylohyoid muscle

A deficiency in the mylohyoid muscle, usually with a herniation of part of the sublingual gland and fat tissue through it, was present in 82 (27.3%) of 300 half-heads dissected. In 17 (11.3%) of the cadavers the condition was bilateral. The hiatus appeared as a transverse fissure between the fibers or as a broader round or oval opening. In some cases the herniation was found constricted at its base; in others the base was broad. The importance of these herniations for diagnostic and surgical purposes is stressed, and the possible factors in their development are analyzed.

Temperature Changes in the Different Parts of the Rabbit's Oviduct

THE BIOPROCESSES that bring about passage of a fertilized and dividing egg to its normal locus of implantation terminating in a normal intrauterine pregnancy take place in various anatomic portions of the oviduct. Lately researchers have concentrated on the various areas of the oviduct as having, at least hypothetically, different functions in the fertilization process, e.g. the fimbrial apparatus, which captâtes the egg, the ampulloisthmic area, which may be considered as the site of fertilization in the rabbit, and the uterotubal junction, which regulates the mechanism of transport of the egg through the oviduct. The oviduct is the site of intense metabolic activity, which may be related to the fluctuations of its vascularity. It is thus possible that an investigation of this vascularity will explain the differences in the volume of collected fluid in various parts of the oviduct, and even the difference in the chemical composition of this fluid. Markee, in 1932, first described changes in the vascularization of the uterus as being a function of the normal ovarian hormonal cycle. His findings were based upon direct observations of the blood vessels at various cycle times in rabbits, guinea pigs, and monkeys. Reynolds showed that one can

Hallux sesamoid bones. Anatomical observations with special reference to osteoarthritis and hallux valgus

SummaryThe normal characteristics of the hallux sesamoid bones were studied in 200 toes (100 dissections and 100 radiographs from patients with hallux valgus), and pathological changes were recorded. Normally each sesamoid articulated with a separate groove on the plantar surface of the first metatarsal head. A bony ridge on the head separated these grooves.Bipartite sesamoids were found in 4% of the toes. Osteoarthritic changes manifested by deformity, irregularity, lipping, cysts in the sesamoids and in the heads of the first metatarsal and erosions in the articular surfaces were present in 32% of the dissected toes. Fusion of the sesamoids was found in 6%. Ankylosis between the sesamoids and the head of the metatarsal was observed in 4%.In the toes affected by hallux valgus the sesamoids, together with the plantar pad and the tendon of the flexor hallucis brevis, were displaced laterally to a variable degree. In severe deformities the lateral sesamoid was dislocated lateral to the first metatarsal head and the medial sesamoid occupied the groove originally corresponding to the lateral sesamoid, while the metatarsal ridge separating the two sesamoids tended to disappear. Osteoarthritis of the metatarsophalangeal joint frequently accompanied hallux valgus.

The inguinal region: anatomic differences in men and women with reference to hernia formation.

Fifty inguinal regions were dissected in anatomic human adult specimens, of which 26 were males and 24 females. The comparison of anatomic variations in both sexes showed that the distance between the public tubercle and the internal ring was larger, and the rectus muscle significantly wider in females. The diameter of the internal ring was larger in males, however, with significant variability. No differences were found regarding the presence or absence of the conjoint tendon. The anatomic variations may explain the sex differences in hernia formation.

Thoracic sympathetic trunk compression by osteophytes associated with arthritis of the costovertebral joint. Anatomical and clinical considerations.

Hyperostosis (lipping) due to costovertebral arthritis was found frequently (84.3%) impinging on the sympathetic trunks (ganglia and cord), rami communicantes and roots of the splanchnic nerves on both sides of the spine in more than 1,000 dissecting room cadavers examined and 34 cadavers of adult and elderly people specially dissected. As a result of the compression, the affected sympathetic structures were angulated, deflected from their course, enlarged and often infiltrated with connective tissue. The possible symptoms which may result from this kind of compression are discussed.

Whorl patterns on fingertips: Their classification as based on the proportionality of their ulnar and radial ridge counts

Three categories of whorls—ulnar oriented (Wu), radial oriented (Wr) and symmetrical whorls (Ws)—are recognized by the proportional representation of their two ridge counts (RC). In the Wu the radial RC is greater, in the Wr the ulnar RC is greater, and in the Ws the two RCs are equal. These three categories of whorls are distinguished from one another by their frequencies, their distribution on individual fingers, and their mean ridge counts. The differences between Wu, Wr and Ws are analogous to those observed between the three other pattern types, namely, the ulnar loops, radial loops and arches.

The lienorenal ligament and the tail of the pancreas: a surgical anatomical study.

Only brief descriptions of the lienorenal ligament and the anatomical relationship between the tail of the pancreas and the hilus of the spleen have been reported in the literature. The anatomical variations in this region are of significant surgical importance. The lienorenal ligament was studied in 37 anatomical specimens. A classification of its variations is presented, and clinical-surgical applications are discussed.