A gross anatomical study of the styloid process of the temporal bone in Japanese cadavers

BACKGROUND

The incidence of an elongated styloid process (SP) and average length and diameter of SP have not been reported using Japanese cadavers. Data on the female-to-male ratio of an elongated SP vary. We calculated the average length and diameter of SP in Japanese cadavers and compared SP lengths between sexes.

MATERIALS AND METHODS

Twenty-seven sides (right and left of bodies) in males and 51 sides in females were analyzed. Measurements were obtained from the inferior external acoustic meatus to the distal tip of the SP. SP diameters at the proximal base, midpoint, and distal tip were measured. SP >30 mm was considered elongated. We used Welch's t-test for the statistical analysis. Fisher's exact two-tailed test was also performed to analyze the female-to-male elongation ratio. A p-value <0.05 was considered statistically significant.

RESULTS

SP elongation prevalence was 29.5% in our sample. The average full length was 27.04±7.88 mm overall; the average diameters were 5.41±1.77 mm at the proximal base and 2.21±1.22 mm at the distal tip. The average SP measurement was 26.81±5.92 mm in males and 27.16±8.79 mm in females (p=0.74). The female-to-male ratio of SP elongation was 1:2 (p=0.041). Females had longer full lengths of non-elongated SPs than males (p=0.004). Males had wider diameters at the proximal base of elongated SPs than females (p=0.017).

CONCLUSIONS

The average length of SP was 27.04 mm in the Japanese population and about 30% of the Japanese presented SP≥30 mm. Male had significantly higher rate than female among the SP≥30 mm, and female had significantly longer SPs than male among the SP<30 mm. Anatomically, the SP gets narrow as distally goes. Our anatomical findings would be beneficial to creating treatment plans, diagnosis, and surgery.

A Bilateral, Non-syndromic, Type III Second Branchial Arch Sinus in a Neonate: a Case Report

The incidence of a second branchial arch sinus accounts for 26-60% of all existing congenital malformations deriving from the branchial apparatus. They are most usually detected between 14 months and 7 years of age, while their incidence during neonatal period and infancy accounts for 0.06% of all cases. The aim of this case study is to emphasize three rare characteristic features: the manifestation during neonatal period, the bilateral localization and the ultrasonographic diagnostic documentation. A 25 days old girl was admitted by her parents due to the presence of mucoid excretion from two small openings found on the neck. These openings were found bilaterally, between the mid and lower third of the anterior border of sternocleidomastoid muscle. Diagnosis was confirmed via ultrasonography. The patient underwent elective surgery during early infancy and both branchial fistulas were excised. Patient's postoperative course was uneventful.

IN CONCLUSION

- in cases of a bilateral second branchial arch sinus, the branchio-oto-renal (BOR) or branchio-otic (BO) syndromes must be excluded; - ultrasound scan can be used for the thorough evaluation of the sinus anatomic course and the relationship with the adjacent anatomic structures; - rompt diagnosis and early therapeutic intervention, even during neonatal period, ensures an uneventful post-operation course.