Morphometric and Topographic Features of Stylomastoid Foramen and its Clinical Significance in Facial Nerve Block.

Objective This study aims to determine the topographic localization of the stylomastoid foramen (SF) and its morphometric relationship with the surrounding bony landmarks. Design A descriptive anatomical study. Setting Anatomy Laboratory of the Faculty of Medicine. Participants Measurements were performed on 53 dry temporal bones. Main Outcome Measures On the inferior and lateral aspects of photographic images, lines and angles were defined. The most lateral end of the SF (SF1) and the transverse medial-lateral line that passes through the upper end of the anterior border of mastoid process (line 1) were used as reference points for topographic evaluation. The upper end of the anterior border of mastoid process (A) and the tip of mastoid process (B) were considered in defining angles. The dates about SF were evaluated using the ImageJ 1.46r software and digital caliper. Results SF1 was classified into three different types based on its topographical localization, stated as Type 1, Type 2, and Type 3. In Type 1, SF1 was located anterior to line 1 (54.7%). SF1 was located posterior to line 1 in Type 2 (34.0%). SF1 was located just over line 1 in Type 3 (11.3%). We also detected angular variations between these types in the inferior and lateral aspects. Conclusion The recommended angles of application are 30 degrees on the horizontal plane and 55 degrees on the sagittal plane for Type 1 when point B is considered. A needle length below 10 mm is more suitable to minimize the potential complications of the nerve block.

Hair Whorl Direction: The Association with Handedness, Footedness, and Eyedness.

Hair whorl direction and handedness were stated to have a common genetic basis in the random recessive model. This study was carried out with a total of 317 healthy young males. The association between hair whorl swirling direction and handedness, footedness and eyedness were assessed. The direction of hair whorl was clockwise at a rate of 76.7%, and counter clock wise at a rate of 23.3%. There was no significant association between hair whorl direction and handedness, footedness, and eyedness (p > .05). The results indicate that hair whorl swirling direction is not an evident marker of functional laterality.

Effect of formaldehyde inhalation on rat livers: a light and electron microscopic study.

It is well known that formaldehyde (FA) is cytotoxic and potentially carcinogenic. Although the individual effects of this reactant on cells has been investigated, the cytotoxicity exerted by the coexistence of FA is poorly understood. The aim of this study was to investigate the effects of FA on the liver in rats, by light and electron microscopic level. We used 18 Wistar albino rats divided into three groups, exposed to 0 (control), 19.7 ppm FA gas for a total of 4 weeks, 8 h/day, 5 days a week (subacute) and 20.3 parts per million (ppm) FA gas for a total of 13 weeks, 8 h/day, 5 days a week (subchronic). After the completion of the exposure period, they were sacrificed by decapitation and their liver tissue samples were taken in order to be processed for light and electron microscopic studies. Light microscopic evaluation of liver tissue samples of FA-exposed rats revealed enlarged sinusoids filled with blood and mononuclear cell infiltration in the portal areas and around the central veins. In addition, some of the hepatocytes showed loss of cytoplasm, and some had a hyperchromatic nucleus. The cells of FA-exposed livers, on the other hand, showed an electron-lucent ground-cytoplasm and a hypertrophy of the smooth-surfaced endoplasmic reticulum. In conclusion, we observed that exposure FA caused diverse histopathological changes indicating the destruction in the liver tissue and this destruction has direct relationship with the length of the exposure period.

Assessment of visualization of structures in the middle ear via Tos modified canal wall-up mastoidectomy versus classic canal wall-up and canal wall-down mastoidectomies.

OBJECTIVE: The aim of this prospective study is to evaluate the differences in the ability to view structures in the middle ear between Tos modified canal wall-up mastoidectomy and classic canal wall-up (CWU) and canal wall-down (CWD) mastoidectomies. METHODS: Eighteen temporal bones of 10 cadaver heads were used. Six bones were randomly selected for each surgical technique (Tos' technique, CWU and CWD mastoidectomies) and fixed on an operating table. In the Tos' technique: (1) transmeatal posterior tympanotomy with drilling of the supero-posterior bony annulus, (2) transmeatal atticotomy with preservation of the bony bridge and (3) cortical mastoidectomy were performed. In the classic CWU mastoidectomy, cortical mastoidectomy and posterior atticotympanotomy (facial recess approach) were performed. Incus and posterior half of the tympanic membrane were removed from all temporal bones. An independent specialist performing otologic surgery evaluated all of the temporal bones and approved the proper extent of dissections. Two another independent observers blinded to the purpose of the study were asked to point five anatomic structures and locations (sinus tympani, anterior attic, posterior crus, lateral attic and the Eustachian tube orifice) in two different sessions. Observers were allowed to rotate the operating table as it has been done during otologic surgery, and the line of view for the observers was both transmastoid and transcanal. The ability to view these structures was recorded as "correct/visible" or "incorrect/invisible". These records were also verified after removing the posterior and superior walls of the outer ear canal in temporal bones of the Tos and CWU groups at the end of the study. RESULTS: Significant differences were found in the ability to view middle ear structures between the Tos' technique and CWU mastoidectomy as well as between CWU and CWD mastoidectomies, with the Tos' and CWD techniques almost equally showing superiority to CWU (p<.0001). Of the five locations, sinus tympani and anterior attic were observed more frequently with the Tos' technique versus CWU (p=.001). Sinus tympani (p<.005), anterior attic (p=.001) and posterior crus (p<.05) were observed more frequently with CWD versus CWU. There was no significant difference in the ability to observe lateral attic and the Eustachian tube orifice among the three techniques. In addition, there was no significant difference in the ability to visualize all the five locations between the Tos' and CWD technique. CONCLUSIONS: Statistical analysis showed good reproducibility of this randomised, blinded study. Tos' modified CWU mastoidectomy, in which most part of the canal wall is intact, showed similar advantage of the CWD in viewing structures in the middle ear. The Tos' technique and CWD mastoidectomy provided better visualization of sinus tympani and anterior attic that are the most frequent places of residual cholesteatoma in the classic CWU mastoidectomy.

The synovial plicae in the knee joint.

OBJECTIVE: To investigate and evaluate the prevalence of 4 kinds of synovial plicae named according to patella, which are inferior, medial, lateral and superior. METHODS: We evaluated plicae in 318 knee arthroscopies through video records, obtained from January 1994 to December 2002 in the Arthroscopy Unit, Department of Orthopedic Surgery, Faculty of Medicine, Trakya University, Edirne, Turkey. In addition, we also investigated plicae in 7 bilateral knee cadavers. RESULTS: In the arthroscopic evaluation, the prevalence of infrapatellar synovial plica was 194 (61%), mediopatellar plica was 302 (95%), lateral patellar plica was 66 (20.7%) and suprapatellar plica was 184 (57.8%). We found that there were 8 (57%) infrapatellar synovial plicae, 13 (92%) mediopatellar plicae, 7 (50%) lateral patellar plicae and 6 (42%) suprapatellar plicae in 14 cadaveric knees. CONCLUSION: We observed a high prevalence of lateral plicae and mediopatellar plicae on the cadavers and the people with arthroscopic diagnosis, and believe our results can contribute to knee anatomy and surgery.

The extensor indicis et medii communis.

The aim of this study was to examine the existence of the extensor indicis et medii communis in detail. Thirty-one randomly selected adult cadavers (62 upper extremities) were examined for this project (22 males and 9 females between the ages 38 and 87). The muscle was observed in 3 of 62 hands, an incidence of 4.8%. One was in the right and the other two were in the left hands. Mean length and width of the muscle belly were 4.5 +/- 0.8 and 0.8 +/- 0.3 mm, respectively. Although the muscle did not have a junctura tendinum attachment between its two tendons, in one hand, the tendon to the index finger gave a thin slip to the tendon of the extensor digitorum communis for the same finger. Knowledge of variant muscle may be important when one is assessing the traumatized or diseased hand.

Anatomical dimensions of anterior bundle of ulnar collateral ligament and its role in elbow stability.

OBJECTIVE: To study the anatomical dimensions of the anterior bundle of ulnar collateral ligament and its role in elbow instability. METHODS: We studied 20 elbows of 10 cadavers. Anterior bundle of ulnar collateral ligament was dissected in all elbows and its anatomical length and width were measured. After measuring it, we assessed the role of the anterior bundle of ulnar collateral ligament in the medial elbow joint stability, with the capsule, the radial head and anterior bundle of ulnar collateral ligament being cut. RESULTS: The mean right length of the anterior bundle of ulnar collateral ligament was 21.10 +/- 6.29 mm and the mean left length was 21.70 +/- 5.31 mm. The mean right width of the anterior bundle of ulnar collateral ligament was 12.70 +/- 2.79 mm and the mean left width was 13.90 +/- 2.37 mm. Anterior bundle of ulnar collateral ligament was found to be the main stabilizer of the valgus stress. The anterior capsule and the radial head also make contributions to this stability. However, when anterior bundle of ulnar collateral ligament is cut, the radial head and the anterior capsule fails to maintain the stability against valgus stress. CONCLUSIONS: The anatomical dimensions of the anterior bundle of ulnar collateral ligament are important for a surgeon when graft is used in reconstructing this ligament. Our study is an initiator of this topic and we believe that with larger series, more reliable anatomical measurements can be obtained. We also showed that the anterior bundle of ulnar collateral ligament is the main medial stabilizer of the elbow joint.

Vortex veins: anatomic investigations on human eyes.

The aim of this study was to determine number of ocular vortex veins, their scleral coordinates, and their relationship with nearby extraocular muscles. Sixty intact cadaver orbits having no history of eye or orbital disorders during life were carefully dissected under stereomicroscopic magnification to expose vortex veins and their exit sites from the eyeball. The number of vortex veins per eye varied from four to eight. Eyes having four (35%) or five (30%) vortex veins were observed most frequently. Three eyes (5%) had eight vortex veins. Although the incidence of the vortex veins was variable, there was at least one vein in each quadrant of the sclera. Knowledge of the approximate location of the vortex vein exit sites is very important for surgeons because damage to these veins during eye surgery could produce potential complications, especially choroidal detachment.

Muscular bridge between the inferior oblique and inferior rectus muscles.

PURPOSE: In this study, we aimed to investigate the muscular bridge between the inferior oblique (IO) and inferior rectus (IR) muscles of the eye. DESIGN: Cohort study. METHODS: The orbits of sixty intact cadavers with no history of eye muscle or orbital disorders during life were carefully dissected to expose the muscular bridge between the IO and IR muscles. Numbers of the bridges, their length and width were recorded. RESULTS: We observed muscular bridge between IO and IR muscles in 6.6% of 60 orbits. They originated from the lateral side of the IR muscle, and joined to posteromedial side of the IO muscle. Mean length and width were 14.2 +/- 6.3 and 1.3 +/- 0.2 mm, respectively. CONCLUSIONS: Muscular bridges were found in 6.6% of orbits dissected. We conclude that muscular bridges are important due to potential cause of failed IO or IR muscles surgery. In this respect, before surgery of the extraocular muscles, the muscular bridges should be kept in mind and demonstrated by computed tomography or magnetic resonance imaging in transverse, sagittal, and coronal planes.