Quantitative site of the related structures for approach of blocking the facial nerve

Fu WANG; Congru QI; Guojun YANG; Zhihong CHEN

ABSTRACT

BACKGROUND:

The blocking treatment can improve the clinic symptom of facial spasm. But the site, depth and the angle of puncturing point are very difficult to be defined, which will seriously infect the curative effect.

OBJECTIVE:

To study the applied anatomy of the related structures of facial muscle for blocking the facial nerve, and to provide anatomical bases for accurate puncturing point and preventing complications.

DESIGN:

An observation study based on cadavers and making the mimic puncture and measuring the correlative structures with anatomical method.

SETTING:

Department of anatomy in a medical college.

PARTICIPANTS:

Totally 28 adult male cadavers(56 sides) were used and the correlative index were measured.

METHODS:

The blocking point was located at the convergent point of the interior edge of cartilage of the external acoustic canal, the anterior fringe of mastoid processes and the posterior fringe of mandible ramus, the needle must be thrust vertically to the median sagittal plane. The puncturing needle stopped until it was barred. A longitudinal incision was made from the puncturing point to mandibula angle, and skin, superficial fascia were cut separately. Then carotid superficial fascia was cut from the posterior fringe of parotidean. The facial nerve trunk and the posterior auricular artery were preserved in site. A blunt isolation was made along its incision. Jugular glomus was appeared. Then the correlative index were measured and dealt with statistics method.MAIN OUTCOME

MEASURES:

The puncturing point, angle and depth,the distance between facial nerve trunk and puncturing point, the position relationship between facial nerve and puncturing needle and the distance relationship between facial nerve and principal structures adjacent to it.

RESULTS:

The blocking point was located at the convergent point of the interior edge of the external acoustic canal, the anterior fringe of mastoid processes and the posterior fringe of mandible ramus, the needle must be thrust vertically to the median sagittal plane. On the left side, the puncturing depth was (19.91 ± 0.09) mm, On the right side, the puncturing depth was(19.28±0. 10) mm.

CONCLUSION:

The experimental study could provide accurate puncturing point, angle and depth for blocking the facial nerve and bring the blocking treatment into full play.