xRead - May 2023

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C. Nduka et al.

difficult to discern. Gently pushing upon the upper lip in an upward and backward direction should clearly demonstrate the location of the fold (Figure 1). If the fold is mal positioned, it is invariably sited too laterally, therefore if in doubt, the fold should be placed more medially. Paletz et al. examined the shape of the normal smile in the non-paralysed face by analysing consistent reference points on the subjects lips, alar bases and nasolabial folds. 9 They found that in all subjects, the alar base, nasolabial fold, mid-upper lip and oral commissure all move in a supra lateral direction on smiling. The greatest movement, as expected, was measured at the commissure, but interest ingly the average movement was only 14 mm (range 7 e 22 mm). Another important point was that there is significant upward movement at the alar base, as well as the upper lip, which emphasises the importance of a vertical vector at these sites. They note that insertion at the commissure alone will result in a sagging appearance of the upper lip, a common stigmata of static suspensions. Another relevant finding of importance for accurate tendon insertion is that the supra-lateral movement observed at the nasola bial fold is less than that seen at the oral commissure and upper lip. There is evidence that the nasolabial fold moves passively on smiling as the muscular insertions are medial to it. If reanimation is therefore performed by insertion of the muscle primarily to the fold then smiling will result in an increase in the fold-vermillion distance, which is undesir able. Finally, Peletz et al. noted that whereas there was significant variability in the magnitude of the motion on corresponding sides of the face, the actual direction of movement was extremely symmetrical. This once again reinforces the importance of pre-operative smile analysis, ideally with pictures taken before facial paralysis (which may distort and exaggerate the normal side).

base to the corner of the mouth without the interposition of either fascia lata or tendon material. This avoids the need to overcorrect at the time of surgery in order to counteract the inevitable stretching that occurs in the non vascularized graft. Furthermore, the contour deformity that follows the Gillies technique and its modifications 4,8 is avoided due to lengthening the tendon at the expense of the posterior portion by anterior rotation of the temporalis. The lengthening observed indeed represents a true increase in muscle length with a cadaveric study showing an average 4 cm lengthening of the temporalis muscle being achieved using this technique. 6 In addition, the line of pull is under the zygomatic arch, posterior to the plane of the cheek. This reproduces the vector on the normal side and thus avoids a contour defect in the cheek. Finally, the tethering that is seen in the subcutaneous passage of a free flap or fascia lata can be avoided through the creation of a gliding plane achieved by passing directly through Bichat’s fat pad to the nasolabial fold. Since the first publication of the LTM, it has become clear from the correspondence from a number of surgeons that certain technical issues need particular attention to detail. This paper highlights important technical stages of the LTM which have been refined over the last 10 years. The critical steps for success are (a) pre-operative smile anal ysis, (b) avoidance of temporal hollowing, (c) accurate tendon insertion to the lip, and (d) adjunctive procedures.

Materials and methods

To date 116 LTM procedures have been performed by the senior author (D.L.) the various aetiologies of facial palsy within this study group are illustrated within Graph 1.

Aetiology of facial palsy within the study group

3%

Acoustic neuroma Congenital Trauma Others Infective Parotid Tumour Cholestatoma

6% 5%

37%

8%

14%

27%

Aetiologies of facial palsy within the cohort.

Graph 1

Unfortunately as of yet there is no accepted method for objectively appraising both the function and aesthetic outcomes following facial reanimation surgery. Critical appraisal of the results of these procedures has led us to focus on the following points to achieve an aesthetic smile.

Pre-operative smile analysis: the importance of the key-points for muscular insertion

Careful evaluation of the patient will help to determine the preferential sites of temporalis insertion and the patient should be examined in both a sitting and supine position to locate the nasolabial fold. Locating the nasolabial fold is usually straightforward, however in young patients or those with long-standing complete palsy the fold may be more

Figure 1 The affected side will lack a defined nasolabial fold. The anatomical position of the nasolabial fold can be demonstrated however by gentle upwards pressure on the upper lip.