Horsley does not open the antrum but lifts the orbital contents, including the periosteum, follows the nerve along the canal by means of sharp-pointed bone forceps, and thus follows it up to the foramen rotundum, where it is evulsed as above. (See [Fig. 399].)
Luecke years ago devised a method of lateral approach, attacking the ganglion and the nerve from the temporal region. An incision is made from the external angle of the orbit straight downward in the direction of the molar teeth, where it is met by another extending from the middle root of the zygoma, downward and forward. Through these incisions the zygoma is exposed and divided. Thus an osteoplastic flap is formed which is laid up over the temporal region, the divided piece of bone being raised with the overlying skin and not detached. This exposes the temporal and zygomatic fossæ. The temporal muscle is then drawn backward with a hook, the fatty tissue which fills these fossæ cleaned out, and the nerve sought for in the sphenomaxillary fossa, where both it and Meckel’s ganglion may be extirpated. The flap is then turned down and fastened in place ([Fig. 400]).
Fig. 399
Branches of the inferior maxillary nerve which most concern the surgeon: a, auriculo-temporal; b, inf. dental; c, buccal. (Marion.)
Fig. 400
Exposure of Meckel’s and the Gasserian ganglia by temporary resection of the zygoma; Luecke’s method. (Marion.)
The inferior dental, or third division of the fifth nerve, may be reached in several ways: Its terminal portion where it escapes at the mental foramen; its upper portion by an incision two inches along the lower border of the jaw and above the angle, the masseter muscle being separated from the jaw, and the ascending ramus opened with a ³⁄₄-inch trephine at a point 1¹⁄₄ inches above the angle, its upper edge ¹⁄₄ inch below the sigmoid notch. The nerve is here exposed before it enters the canal. The lingual nerve may also be found resting upon the internal pterygoid muscle. A ligature tied around each nerve, for traction purposes, permits easy tracing of their trunks to the foramen ovale, where, after vigorous stretching, they are divided. They should then be traced downward and at least one inch of their trunks removed.