Indications and Techniques for Palatal Spacer Grafts



Indications and Techniques for Palatal Spacer Grafts


Dev Vibhakar

Erez Dayan

Michael J. Yaremchuk





DEFINITION



  • Retraction of the lower eyelid is a consequence of various surgical and medical conditions affecting the periorbital and midface region.


  • Craniofacial trauma, tumors, facial paralysis, thyroid eye disease, and cosmetic blepharoplasty can alter the position of the normal lower eyelid.


  • The clinical manifestation of this is inferior scleral show, lagophthalmos, and exposure keratitis. This can lead to dry eye syndrome, ocular discomfort, excessive tearing, photophobia, and blurred vision, as well as a cosmetically unappealing sad-eyed appearance.1


  • Placement of a graft of palatal mucosa between the tarsal plate and lower lid retractors can elevate the lower lid margin.2,3


ANATOMY



  • The normal lower eyelid lies at or just above the inferior corneal limbus.


  • It is tethered medially and laterally by the canthal tendons.


  • The lateral canthal angle is approximately 4.1 degrees or 1.2 mm higher than the medial canthal angle.


  • It is considered a trilamellar structure—the anterior lamella (skin and orbicularis oculi muscle), the middle lamella (orbital septum), and the posterior lamella (lower eyelid retractors and conjunctiva (FIG 1A).






    FIG 1 • A. Lower eyelid anatomy demonstrating the anterior lamella (skin and orbicularis oculi muscle), the middle lamella (orbital septum), and the posterior lamella (lower eyelid retractors and conjunctiva).


  • The hard palate is composed of keratinized stratified squamous epithelium.


  • There is no sex difference in mucosal thickness, and it increases with greater distance from the marginal gingiva, the mucosa being thinnest near the first molar.


  • The bones of the hard palate are the palatine processes of the maxilla anteriorly and the horizontal plates of the palatine bones posteriorly.


  • The greater palatine neurovascular bundles emerge bilaterally from the greater palatine foramina most commonly found medial to the upper second molar.


  • They pass anteriorly along grooves in the palate to enter the incisive foramina (FIG 1B).


PATHOGENESIS



  • Lower lid retraction can result from shortening of any of the lower eyelid lamella.


  • This results in vertical contracture of the lower lid and is most commonly seen because of trauma or aggressive lower lid blepharoplasty.


  • Patients with thyroid eye disease have a relative lower eyelid deficiency due to its inferior displacement caused by globe prominence.


  • When lower lid malposition is caused by middle and posterior lamella inadequacy, grafts of palatal mucosa placed beneath the tarsal plate provide increase height and stiffness to support and elevate the lower lid margin (FIG 2).







FIG 1 (Continued) • B. Relevant palatal neurovascular anatomy for donor-site harvest.






FIG 2 • A,B. Lower lid malposition secondary to vertical contracture of scarred septum. C-E. Hard palate mucosal graft used as a spacer between the lower tarsal plate and the recessed conjunctiva, lower eyelid retractors, and orbital septum.



PATIENT HISTORY AND PHYSICAL FINDINGS



  • The underlying cause (previous surgery, metabolic disease, trauma, skeletal morphology) of lower eyelid retraction is determined.


  • A thorough ophthalmologic examination is performed.


  • Measuring the inferior scleral show assesses the degree of lower lid displacement.


  • The status of the lower lid lamellae, skeletal morphology, and cheek prominence is assessed.


  • Deficiencies of the middle and posterior lamellae are indications for the use of spacer grafts.


SURGICAL MANAGEMENT


Preoperative Planning

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Nov 12, 2019 | Posted by in Aesthetic plastic surgery | Comments Off on Indications and Techniques for Palatal Spacer Grafts

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