Determination of dimensions and angles of mandible in the fetal period.

The aim of the present study was to determine the dimensions of the mandible during the fetal period, the relationship between the growth rates of the angle of the mandible and the dimensions of the mandible. Furthermore the angle of union of the two halves of the body of the mandible on the horizontal mandibular plane, which was not described elsewhere, is explored in this study. One hundred and sixty-one human fetuses (83 males and 78 females) without any cranio-facial or mandibular asymmetry, external pathology or anomaly and aged between 9 and 40 weeks of gestation were used in the study. Cases were stratified into four groups according to their developmental ages, that is, first trimester, second trimester, third trimester, and term fetuses. Cranio-facial parameters in addition to bi-condylar, bi-gonial, bi-mental tubercular, condyle-gonion, gonion-mental tubercle, condyle-mental tubercle, gonion-pogonion distances were measured. The degree of the angle of the mandible, angle of union of the two halves of the body of the mandible and sagittal length of the base of the mandible were calculated. The means of the parameters with respect to gestational weeks and groups were computed. While there were no sex differences in any of the parameters (P>0.05) there were very significant relationships between gestational age and parameters (P<0.001). The mean degree of the angle of the mandible during the fetal period was 122+/-8 degrees . The mean alpha angle of the base of the mandible was 65+/-8 degrees . None of these angles varied significantly throughout the fetal period. Height of the ramus of the mandible increased more than the length of the body of the mandible and bi-gonial distance in the first and second trimesters while in the third trimester and term period they increased at the same rate. Comparisons of groups for the ratio of the transverse to the sagittal lengths of the mandible revealed significant differences between first and second trimesters with term group (P<0.05). Accordingly, bi-gonial distance of the mandible increased more during the third trimester and term time than the first and second trimesters, compared with the sagittal length of the mandible. The morphometric features and architectural changes observed in the mandible do not totally occur during the fetal period but continue later in childhood and adulthood.

Accessibility of calf perforating veins from the superficial posterior compartment: an anatomic dissection study.

OBJECTIVES: to determine the anatomic location of medial perforating veins (PVs) and their course within the compartments of the leg. MATERIALS AND METHODS: the lower extremity veins of 15 cadavers were filled with coloured latex solution. Medial PVs between the ankle and the knee were dissected out. RESULTS: in total 95 direct PVs (mean 6.3 per extremity, range 3-9) were identified and classifed as Cockett I, II, or III, proximal and distal paratibial and Boyd. Cockett PVs were present in more than half of the cases, of which the majority (except Cockett I) were located in the superficial posterior compartment. Whereas the vast majority of Cockett PVs originate from the posterior arch vein, the other perforators originate from the greater saphenous vein. CONCLUSIONS: only 62% of all PVs pass through the superficial posterior compartment. As a result, during subfascial endoscopic perforating vein surgery (SEPS), at least one third of patients require a paratibial fasciotomy in order to reach and ligate the PVs.