Traits considered for sex estimation included the: ventral arc, subpubic
concavity, ischiopubic ramus ridge, greater sciatic notch, nuchal crest, mastoid processes, supraorbital margin, supraorbital ridge and mental eminence.
Patient selection criteria for vacuum extraction Good candidates Marginal candidates Poor candidates Multiparous Prim parous Protraction disorders 2nd stage Pregnancy at term Pregnancy is post term LGA fetus Wide subpubic
arch Average subpubic
arch Narrow subpubic
arch Good maternal Gestational diabetes Poor maternal compliance compliance Fetus in OA position Fetus in OP position Uncertain position of fetal head Arrest disorders Deflexion, asynclitism Abbreviations: LGA, large for gestational age; OA, occiput anterior; OP, occiput posterior.
They include (1) a narrow pelvis (even if the bones are more robust in males), (2) a narrow sciatic notch in males (~30[degrees]), (3) a narrow subpubic
angle, (4) absent or shallow pre-auricular sulcus (deep groove in females), (5) flat auricular area of the ilium (area of articulation with the sacrum), (6) larger symphyseal face in males, (7) flat medial portion of the ischiopubic ramus in males, (8) larger acetabulum in males, (9) shorter pubis in males, and (10) no ventral arc on the pubis (Stewart, 1968; Krogman & Iscan, 1986).
In this regard, it is similar to the calcaneal angle (Didia & Dimkpa, 1999) but is unlike the subpubic
angle (Nwoha, 1992), which has been shown to be sexually dimorphic in Nigerians.