Midface Rejuvenation

40. Midface Rejuvenation


Sumeet Sorel Teotia, Sami U. Khan, Foad Nahai


The human “middle of the face,” often called midface, is a loosely applied anatomic term that mainly focuses on the soft transition from the lower eyelid inferiorly toward the rounder, upper cheek as it transitions into the lateral face, upper lip, and soft tissue of the nasal sidewall. Thus a midface problem arises when any anatomic component within this region begins the aging process.


HISTORY


In the early twentieth century, surgical procedures to address facial aging consisted of skin and subcutaneous facelifts. These interventions had no effect on the midface.


RENAISSANCE ERA (1970s)1


Early 1970s: Skoog2 described subsuperficial musculoaponeurotic system (sub-SMAS) dissection.


1976: Mitz and Peyronie3 defined SMAS.


Late 1970s: Focus changed to dissecting, dividing, and repositioning the SMAS.


These advances improved the appearance of the lower third of the face and neck, but not the midface.


DIFFERENT PLANES OF DISSECTION ERA (1980-1992)1


Craniofacial surgeons, like Tessier,4 introduced subperiosteal approaches to better reposition facial soft tissues.


“Mask lift”: subperiosteal dissection of the malar region, zygomatic arches, and orbital region


Soft tissues dissected and redraped over the facial skeleton to rejuvenate the face


1984: Psillakis5 attempted to reposition/elevate the soft tissues of the orbital and malar region by undermining the superficial temporofrontal fascia and fixing it to the aponeurosis of the temporalis.


1990: Hamra6 introduced the deep plane rhytidectomy, combining a Skoog-type sub-SMAS dissection over the zygomaticus musculature and medially to fully release the nasolabial fold. This allowed total release of the all SMAS attachments. The flap was advanced laterally and fixed to the superficial temporal fascia.


1992: Hamra7 refined his technique to improve midface rejuvenation with the “composite rhytidectomy.” Through a transblepharoplasty incision, the orbicularis oculi was undermined, and this plane was connected to the facelift dissection plane. This created a composite flap of orbicularis muscle, cheek fat, and platysma, which, when repositioned, addressed the three major areas of soft tissue ptosis.


1992: Barton8 provided a better understanding of the sub-SMAS plane and its relationship to the nasolabial fold. Anatomically, within the medial cheek the SMAS becomes the investing fascia of the zygomaticus major and minor.


Thus, simple SMAS manipulation does not significantly improve the appearance of the deepened nasolabial fold.


He recommended that, to address the fold, medial to the zygomaticus musculature the dissection must transition to skin-subcutaneous tissue plane to release the tethering effect of the SMAS.


1993: Owsley9 defined the malar fat pad as a “discrete area of bulky subcutaneous fat, which overlies the maxillary zygomatic region.” The fat pad is triangular in shape and has its base at the nasolabial fold. He advocated dissecting below the fat pad to completely mobilize it and then suspending it under tension to the subcutaneous fascia over the malar eminence with a vector perpendicular to the nasolabial crease (Fig. 40-1).



image

Fig. 40-1 Elevation and mobilization of the malar fat pad.


ADVANCED TECHNIQUES ERA (1992-1999)2


1992: Terino10 described his concept of addressing the “fourth plane.”


Advocated the use of alloplastic facial augmentation in conjunction with concepts of facial zonal anatomy to address volume loss in the midface


1993: Flowers11 describes the tear trough deformity and used alloplastic implants for volumetric correction.


1994: Coleman12 posed the question “Should we support and fill or should we excise and suspend?”


Popularized lipoinfiltration for soft tissue augmentation and lifting in the periorbital region through fat grafting


1994: Facial surgeons, including Fuente del Campo,13 Isse,14 and Ramirez,15 started to incorporate the endoscope into facial rejuvenation.


1995: Ramirez described six types of procedure combinations for rejuvenation of the upper and middle third of the face.


Types four through six addressed the midface and consisted of full open, full endoscopic, and biplanar combined procedures.


VECTORS AND VOLUME ERA (1999-PRESENT)1


Concepts of volume management of the midface and correct vector of elevation/pull


Little15,16 described a volumetric approach to midface rejuvenation, both in the subcutaneous and subperiosteal plane.


Significant anatomic studies refined the complex anatomy of the midface/periorbital region.


Vectors of pull in rejuvenative surgery were reassessed, and a more vertically oriented direction of pull was advocated, especially for procedures addressing the midface.


PERTINENT ANATOMY


BASIC DEFINITION OF THE MIDFACE


Portion of the cheek medial to a line extending from the frontal process of the zygoma to the oral commissure and from the lower lid above to the nasolabial fold below17


Anatomically, the midface thus encompasses complex relationships of the lower lid, the nasolabial fold, the upper lip, and the malar eminence/cheek.


BASIC ANATOMY18,19


Skeleton


Main determinant of contour of the midface, although the thickness of the soft tissue component is important, especially with changes in aging


Serves as platform for attachment of the overlying ligaments and muscles, which support the midface soft tissues


Upper/outer prezygomatic portion: Overlies the body of the zygoma


Lower/medial portion: Overlies the maxilla; covers the vestibule of the oral cavity


Soft tissue


Suborbicularis oculi fat (SOOF)


Posterior to muscle


May require reduction, repositioning, or nothing


Temporal fat pad


Superior to zygoma between superficial and deep layers of temporal fascia


Malar fat pad


Main midface soft tissue structure


Triangular


Changes with age: Flattens, loses projection, loses volume, elongates, becomes narrower, and displaces inferiorly


Buccal fat pad


Superficial to the periosteum overlying the maxilla at the lateral buttress


Important support structure for the cheek mass


SMAS


Adipofascial layer superficial to the parotid fascia and mimetic muscles


Laterally anchored to the parotid fascia and at the osteocutaneous ligament of the zygoma and mandible


Midface elevation often achieved by elevating the SMAS in the midfacial region


Mainstay of SMAS facelift procedures for addressing facial aging in the midface region


Retaining ligaments


Midface retaining ligaments20 (Fig. 40-2)



image

Fig. 40-2 Retaining ligaments of the midface and orbit.


Orbicularis retaining ligament21


Zygomatic ligament


Upper masseteric ligament


Nasolabial fold (see Chapter 43)


Confluence of SMAS, dermis, and muscle fascia overlying muscles of facial expression


Complex facial anatomic structure


Prominence adds to aged appearance


Contributes to midface aging


Surgical correction is complex and controversial as to the ideal procedure.


Tear trough (see Chapter 37) (Fig. 40-3)



image

Fig. 40-3 Tear trough.


Also known as nasojugal groove


Prominence increases with age


Medial aspect of the lower eyelid


Becomes more prominent with loss of cheek volume and descent of midface structures; groove often accentuated by herniated orbital fat


Anatomic cause of groove is controversial.


Some surgeons think it is the prominence of the orbital rim after descent of the malar fat pad.


Probably is triangular confluence of the inferomedial orbicularis oculi, levator alaeque nasi, and levator labii superioris, which is located inferior to the orbital rim and becomes apparent with volume loss in this area.


Muscles


Orbicularis oculi


Most affected in midface lift procedures


Sphincteric muscle originating from the orbital bones and inserting into the soft tissues of the eyelids



TIP: Repositioning the lateral canthus and orbicularis oculi muscle, thus shortening the apparent length of the lower eyelid, is crucial to re-creating a youthful appearance of the periorbital region and midface.


Zygomaticus major: Important for smiling


Major anatomic landmark in dissection of midface procedures


Risorius: Important for smiling


Levator labii superioris


Orbicularis oris


Masseter


Skin


Blood supply18 (Fig. 40-4)



image

Fig. 40-4 Blood supply.


Mainly from branches of the external carotid artery


Significant anastomoses with the internal carotid artery system exist in the periorbital region


Facial artery


Internal maxillary artery


Infraorbital artery


Supplies the lower eyelid and midcheek


May be injured during subperiosteal midface dissection as it exits its foramen


Superficial temporal artery


Travels within the SMAS layer as it crosses the zygomatic arch


Protected in sub-SMAS dissection


Transverse facial artery


Supplies lateral canthal region


Innervation


Sensory: Branches of CN V2 (trigeminal)


Infraorbital nerve


Zygomaticofacial nerve


Posterior maxillary nerve


Motor: Zygomatic and buccal branches of facial nerve (CN VII)


Orbicularis oculi is predominantly supplied by zygomatic branches that mainly enter near inferior lateral aspect entering on the posterior aspect of the muscle.


Lower lid receives additional innervation from a buccal branch from the midcheek, which passes deep to the zygomaticus major.


Additional buccal branches extend medially.


In general, in midface surgery, injury to a distal branch rarely results in a noticeable deficit.


APPLIED ANATOMY


The midface is divided into an anterior and a lateral segment.


Anterior segment is called the midcheek.22


Midcheek is the portion of the midface on the anterior aspect of the face, extending from the lower eyelid caudally to the nasolabial groove and upper lip22 (Fig. 40-5, A).



image

Fig. 40-5 Subcutaneous compartments of the midcheek.


The aesthetically pleasing fullness of the youthful cheek is produced by the midcheek.


As a person ages, changes in the midcheek reveal that it comprises three distinct anatomic structures22 (Fig. 40-5, B).


1. Lid-cheek segment


2. Malar segment


3. Nasolabial segment


Understanding the influence of each of these structures and the changes affecting each during the aging process is important to adequately correct changes that occur over time.


As the aging process progresses and affects these three structures, the midcheek segments become separated by three cutaneous grooves.22


1. Palpebromalar groove: superolaterally


2. Nasojugal groove: Medially


3. Midcheek groove: Inferolaterally


These three grooves intersect to form an obliquely oriented Y.22


The midcheek groove runs essentially parallel to the nasolabial fold; cephalically, it extends into the nasojugal groove.


The palpebromalar groove extends laterally toward the lateral canthus at the cephalic limit of the midcheek.


Changes With Aging


Loss of skin elasticity from decreased collagen


Epidermal thinning and the development of rhytids


Loss of fat volume


Descent of soft tissues from attenuation of ligamentous structures, causing the development of prominent grooves and a gaunt look from volume loss


Changes in the skeletal support structure of the midface


Midface shape defined by specific shape and projection of the orbital bones, zygoma, and maxilla


May be the most influential factor creating individual variation of facial appearance


Studies have shown the changes in the bone structure of the midface with age.


Pessa et al23 suggested that age-related changes in bone structure led to posterior retrusion of the inferior orbital rim and the anterior maxilla.


Using facial CT scans to assess midface skeletal changes in male and female patients, Mendelson et al24 found that the angle between the anterior maxilla and the orbital floor decreased in both sexes over time.


Yet, in contrast to previous reports, Mendelson found that the inferior orbital rim remained relatively fixed. Thus, the retrusion of the anterior maxillary wall in relation to the fixed inferior orbital rim leads to the “negative vector” appearance of the lid-cheek junction, as described by Jelks et al.25


Shaw and Kahn26 also used CT evaluation to show significant decrease in the glabellar and maxillary angles with increasing age.


These studies all contrast the earlier notion that facial skeletal aging changes consisted of growth and expansion with advancing age.


Recent data intuitively make sense, because these skeletal structures serve as the foundation of the midface soft tissues and the site of attachment of the muscles of the lower lid and upper lip and the supporting/retaining ligaments of the midface.


Pessa et al23 and Mendelson et al24 showed greater changes in maxillary angles in males during aging. The posterior displacement of the anterior maxilla leads to loss of soft tissue support, which, in addition to soft tissue volume loss, accentuates the aging changes in the midface.


Skeletal support loss could explain the descent of the malar fat pad/soft tissues and their influence on deepening of the nasolabial fold, which is a fixed structure.


Midface Similarities With the Scalp


The topographic anatomy of the scalp has been described in five layers:


1. Skin


2. Subcutaneous tissue


3. Musculoaponeurotic layer


4. Loose areolar tissue


5. Fixed periosteum and deep fascia


Anatomic structure of the midface can be equated with that of the scalp22 (Fig. 40-6).


Nov 3, 2020 | Posted by in Aesthetic plastic surgery | Comments Off on Midface Rejuvenation

Full access? Get Clinical Tree

Get Clinical Tree app for offline access