Craniofacial Muscles

278 A.O. Grobbelaar and A.C.S. Woollard
lid in clinic to evaluate the required mass. The aim is to achieve approximation of
the lids to within 2–4 mm with the lightest possible weight which is then sutured in
a supratarsal position approximately 4 mm from the lid margin to reduce the possibility
of extrusion (Misra et al. 2000 ) . It is important to stress the need to avoid
inadvertent injury to the levator as this will result in ptosis. Sometimes the weights
have to be adjusted at a secondary procedure to fi ne tune lid approximation. More
recently, there has been some interest in platinum chains which allow better contouring
along the lid margin (Berghaus et al. 2003 ) . Lengthening of the levator has
a similar effect in lowering the upper lid but with the advantage of no arti fi cial prosthesis
or unaesthetic contour deformity that accompanies a gold weight. It is usually
performed by the interposition of a segment of temporalis fascia equal to the gap in
the orbital fi ssure during forced closure (Piggot et al. 1995 ) . It is possible to implant
a dynamic device to assist closure. A palpebral spring can be inserted between the
superior orbital rim and the upper lid margin. This is loaded by the opening action
of the levator and actively closes the eye as the muscle relaxes. Its advantage is that
it works even when the patient is lying down, but results are highly dependent on
the skill and experience of the surgeon (Levine and Shapiro 2000 ) .
The lower lid can be used to provide greater inferior support. Krastinova
described the insertion of an ellipse of conchal cartilage to improve the contour of a
paralyzed lower eyelid (Krastinova et al. 2002 ) . It is important to crush the cartilage
to reduce the incidence of extrusion through the subciliary incision. A McLaughlin’s
lateral tarsorrhaphy procedure provides static support by “double-breasting” the
lateral canthus through resection of the posterior lamella of the upper lid and a corresponding
portion of the anterior lamella of the lower lid (McLaughlin 1952 ) . This
raises the lower lid, narrowing the aperture of the eye and effectively lowering the
upper lid. It is a simple and effective procedure, especially useful in the elderly
where it also improves any ectropion of the lower lid. However, it can give the
appearance of a smaller eye and interfere with lateral gaze. The lower lid tension
can be augmented by a fascial or palmaris sling. This can be tunneled through the
lower lid and fi xed to the medial canthal ligament and the lateral supraorbital margin.
It is vital that the position of the sling relative to the lid margin does not exacerbate
or create ectropion (too low) or entropion (too high). A canthopexy alone
tends to loosen with time and therefore provides insuf fi cient support in facial palsy
cases. Where there is laxity of the medial canthal ligament and ectropion, it can be
addressed with a medial canthopexy or medial tarsal strip and suture fi xation to the
deep periosteum (McLaughlin 1951 ; Lee et al. 2004 ; Collin 1993 ) . This can also
help to address epiphora.
Gilles described a dynamic eyelid closure where by a pedicled transfer of a slip
of the temporalis muscle is turned over and extended across the upper and lower
eyelids via fascial strips to the medial canthal ligament (Gillies 1934 ) . The action of
chewing then causes blinking and lubrication of the cornea. Alternatively the muscle
can be used exclusively for the upper lid as it constitutes the main action of eye
closure, and the lower lid supported with a simple sling. Patients frequently complain
of a bulge at the lateral border of the orbit, a slit-like eye, and of the irritation
caused by eye closure whilst eating. More recently Terzis has reported a free