The Predictability Precision of Superior Semicircular Canal Through Radiological Assessment and Microanatomical Dissection

The Comparison of the Right and Left Sigmoid Sinus Cross-Sectional Areas in Fetal Period and the Factors Affecting the Venous Dominance

OBJECTIVES

Skull base is an important and a challenging area for surgeons. Success in skull base surgery depends on various factors such as pre-operative evaluation, appropriate surgical technique, anesthesia duration, intraoperative neuromonitorization and wound care.

MATERIALS AND METHODS

This study was performed in the Anatomy dissection laboratory of M.U. Medical Faculty (Ethical committee approval number 2010-103). Twelve fetuses between 17-33 gestational weeks fixed with formaldehyde were enrolled to the study.

RESULTS

This study was planned to investigate the cross sectional areas of the sigmoid sinus in three levels to compare the right-left sides and the probable relationship among the levels in fetuses to further delineate the developmental factors on jugular foramen asymmetry. The cross-sectional measurements of sigmoid sinus lumen were done on 3 levels which are described as A1 level; sinodural angle, A2 level; the midpoint between the sinodural angle and endocranial orifice and A3 level as the entrance (endo-cranial orifice) of the jugular foramen. There is a strong positive correlation between left (L) A1 and L A2 and also the same for L A1 and right (R) A2. These strong and positive correlations are all valid between L A2-L A3, L A2-R A2, L A2-R A3, L A3-R A3, R A1-R A2.

CONCLUSION

Multicenter studies would be beneficial to investigate the topic with greater number of fetuses also on the different regions for genetic differences.

Morphometric properties of the facial nerve in fetal temporal bones

OBJECTIVES

The main aim of the study was to examine the development and course of the facial nerve within fetal temporal bones from an anatomical and neuro-otological perspective.

METHODS

The study was conducted on 32 temporal bones from obtained fetuses (7 females, 9 male), on a mean gestational age of 26.75 ± 4.36 (range, 20-34) weeks from the collection of the Anatomy Department of Medicine Faculty. All the measurements were collected with a digital image analysis software.

RESULTS

Neither male/female nor right/left significant differences were observed in relation with the algebraic data of the segment lengths and angles of the facial nerve (p > 0.05). Linear functions for meatal, labyrinthine, tympanic, and mastoid segment lengths of the facial nerve were calculated as: y = -1.206 + 0.200 × Age (weeks), y = -1.868 + 0.153 × Age (weeks), y = -2.327 + 0.325 × Age (weeks), and y = -1.507 + 0.246 × Age (weeks), respectively. In addition, linear functions for first and second genu angles were calculated as: y = 105.475-0.117 × Age (weeks) and y = 140.446-0.042 × Age (weeks), respectively.

CONCLUSION

The regression equations and the scatter plot with increment curve, representing the growth dynamics of the facial nerve can be used for estimating its lengths and for understanding its development. The data suggest that there is a dramatic change transition from fetal life to the gathered data of adulthood in the length of meatal and mastoid segments as well as in the second genu angle; in addition, there is a partial change in the length of labyrinthine and tympanic segments as well as in the first genu angle.