TECHNIQUE FOR PRESERVATION OF THE TEMPORAL BRANCHES OF THE FACIAL NERVE DURING FACE-LIFT OPERATIONS. By RAUL LOEB

Transcription

1 TECHNIQUE FOR PRESERVATION OF THE TEMPORAL BRANCHES OF THE FACIAL NERVE DURING FACE-LIFT OPERATIONS By RAUL LOEB Plastic Surgery Department, Escola PauIista de Medicina, S~o Paulo, Brazil IN general, papers dealing with face-lifting operations do not emphasise adequately techniques for avoiding accidental paralysis of the frontal muscles during undermining. In most of the techniques described, extreme care is advised in order not to cut the rami of the facial nerve but few authors have explained their exact methods in the temporal and zygomatic regions where some surgeons advocate a supra-fascial dissection while others prefer a sub-fascial one. Gonzalez-Ulloa (1962) states that" when passing from the forehead to the temporal region, it is important to change from the supra-periosteal level to a supra-aponeurotic one" and Pangrnan and Wallace (1961) say that "the incision in the temporal area is carried down to include the superficial fascia ". The necessary tension to which the flap needs to be submitted in the temporal area, makes us favour the inclusion of the superficial fascia in its thickness. Consequently in the temporal region we perform a sub-fascial undermining and elevate a flap with good blood supply in order to avoid any necrosis about the suture line. It is our opinion that the extent of the undermining can be generous in the cheek but in the temporal and zygomatic regions, every care must be taken where the temporal ramus of the seventh nerve becomes more superficial next to the temporal process of the zygoma. At the same time, while excessive temporal undermining is dangerous, too little dissection will interfere with the necessary mobilisation of the flap. Sufficient dissection must be carried out in order to allow the surgeon to free the superficial fascia where it fuses with the temporal fascia at the level of the zygomatic arch otherwise the flap will remain anchored to the zygoma, jeopardising the ideal skin and scalp tension in the temporal region. Temporal undermining should only be performed with a precise understanding of the course of the frontal branch of the seventh nerve and the insertions and distributions of the superficial fascia and the zygomatic orbital artery. Anatomical Relations of the Frontal Branch.--The course of the seventh nerve has been analysed by several authors, particularly by McCormack et al. (1954) and Davis et al. (1956) who performed an exhaustive study of the surgical anatomy of the superficial branches, and the relations of the temporal ramus to the superficial fascia. The superficial fascia unites the frontalis and occipitalis muscles extending laterally towards the mastoid and parotideo-masseteric regions, covering in its course the temporal fossa. Cranial to the zygomatic arch the superficial fascia fuses with the temporal fascia. This fusion is usually solid and as Rouvi~re (1959) describes, a thick connective tissue links one aponeurosis to the other. Paturet (1951) also refers to the strong fixation of the superficial aponeurosis to the zygomatic arch and to the temporal fascia. With this basic anatomical data, dissection of 24 unfixed facial halves has been carried out in order to study better the temporal and zygomatic regions, observing with special attention the temporal branches of the seventh nerve and their relation to the superficial fascia and the zygomatic orbital artery. 390

2 FIG. I Schematic drawing showing the approximate level where the temporal and superficial fascias fuse (dotted line). The frontal ramus of the facial nerve usually runs to the forehead muscles following the anterior third of this fusion line. ( ;"/ FIG. 2 Fig. 2.--Lines of incision. FIG. 3 Fig. 3..win the temporal region the undermining is performed between the superficial and temporal fascias.

3 392 BRITISH JOURNAL OF PLASTIC SURGERY ~\~ FASCIA ~ ~ ~ ~MP.~L,5SUPERFICiALIS FIG. 4 The zygomatic orbital artery severed and tied. FASCIA TEMPGRALJS FIG. 5 FIG. 6 Fig. 5.--A supra-fascial elevation of the flap is performed in the zygomatic region. Fig. 6.--Below the zygoma a supra-fascial dissection is performed as far as the anterior border of the fascia parotideo-masseterica.

4 TEMPORAL BRANCHES OF THE FACIAL NERVE 393 Passing from the sub-fascial course of the main temporal branch in the parotideomasseteric region to a supra-fascial one in the zygomatic region, the frontal branch of the seventh nerve will emerge to penetrate the frontal muscles. This emergent course is usually located near the lateral border of the orbit, next to the anterior third of the fusion line of the superficial and temporal fascias. This fusion line assumes an ascending direction at the anterior end of the zygomatic arch (Fig. I). The frontal ramus of the seventh nerve is generally followed very closely by the terminal portion of the zygomatic orbital artery. Preservation of the Frontal Branch.--Since 1962 the following surgical technique has been used in some 4o0 cases and no accidental paralysis of the frontal muscles has been observed. FIo. 7 The fusion line between the superficial and temporal fascia is partially detached along the arch of the zygoma. The incision is shown in Figure 2. On the temporal region it is deepened to the temporal fascia and thereafter undermining proceeds by digital pressure. On account of the fusion of the temporal and superficial fascia, digital dissection is limited anteriorly, next to the temporal border of the frontal process of the zygoma and inferiorly, along the upper border of the zygomatic arch (Fig. 3)- Approximately at the posterior end of the zygomatic arch, the zygomatic orbital branch of the superficial temporal artery is usually severed and tied. The superficial fascia is now divided and the undermining in the parotid-masseteric region begun (Fig. 4). By digital pressure upwards and inwards following a loose supra-fascial cleavage plane, the elevation of the flap is slightly extended in the zygomatic region (Fig. 5)- The supra-fascial undermining proceeds in the zygomatic and buccal regions with blunt-edged scissors, downwards and inwards as far as the anterior border of the fascia covering the parotid and masseteric muscle. A bridge now separates the regions above and below the zygomatic arch. This bridge represents an aponeurotic neuro-vascular bundle in whose upper border runs the zygomatic orbital artery. Close to the orbit the frontal branch of the seventh nerve will traverse the bridge (Fig. 6).

5 394 BRITISH JOURNAL OF PLASTIC SURGERY The fusion line between the superficial fascia and the temporal fascia is freed along the arch for a distance usually of one and a half inches measured from the posterior end of the zygoma (Fig. 7). The distal portion of the zygomatic orbital artery is a helpful landmark on account of its proximity to the frontal branch of the facial nerve. Close to the orbit the zygomatic orbital artery should not be severed again. (If this should happen, profuse bleeding occurs and the frontal branch has most probably been severed.) SUMMARY The anatomical relations of the frontal branch of the facial nerve are outlined and a reliable technique for avoiding its severance during face-lift operations is described. REFERENCES DAVIS, R. A., ANSON, B. J., B~OINGER, J. M. and KURTH, L. R. E. (I956). Surgical anatomy of the facial nerve and parotid gland upon a study of 35o cervico facial halves. Surgery Gynec. Obstet. xo2, 385. GONZALEZ-ULLOA, M. (r962). Facial wrinkles. Integral elimination. Plastic reconstr. Surg. 29, 658. McCORMACK, L. J., CAULDWZLL, E. W. and ANSON, B. J. (I945). The surgical anatomy of the facial nerve ; with special reference to the parotid gland. Surgery Gynec. Obstet. 80, 620. PANGMAN, W. J. and WALLACE, R. M. (I96I). Cosmetic surgery of the face and neck. Plastic reconstr. Surg. ~7, 544. PATURET~ G. (1951). " Trait~ d'anatomie Humaine ". Tome I. Paris : Masson. ROUVIERE~ H. (I959). " Anat. Humana Descriptiva Topogr~ifica ". Tome I. Madrid.