Commissure Reconstruction
Microstomia
Problems:
1. Limited oral intake
2. articulation problems
3. difficulty inserting dental appliances
4. restricted access for routine oral hygiene
5. aesthetic concerns
Causes:
1. Burns – most common
a. most often occur in toddlers who chew on an electrical cord, resulting
in a high-voltage current that arcs via the saliva, injuring one of the
oral commissures.
2. scleroderma
3. Post tumor excision and lip reconstruction
4. congenital
a. Freeman-Sheldon syndrome
b. oro-palatal dysplasia
Management
Oral Appliances
 If a splint is used, it should generally be instituted within 2 weeks of the injury.
 most common device currently used is the microstomia prevention appliance.
 Device is widely available, is simple to use for physicians and patients, and does
not require intact dentition.
 its narrow profile minimizes drooling but those with circumferential lip burns will
need modification to provide vertical expansion
 For infants who will not keep the device in their mouths or are at risk of choking,
similar devices have been constructed that may be secured with elastic headbands
or alternatively with a molded face mask to hold the commissure hooks
CREST syndrome
1. Because of poor tissue healing, surgery is not advised for scleroderma patients
with microstomia
2. Isometric exercises, with or without devices that expand the oral aperture, can
prevent contracture and microstomia, particularly if instituted early in the disease
course.
Burns
1. majority of authors advocate conservative treatment for electric burns, allowing
spontaneous healing to occur, followed at a later stage by reconstructive
procedures,' because of the difficulty of assessing the degree of initial injury and
in order to minimize the loss of valuable normal tissue during early excision
2. Others recommend early debridernent and reconstruction. Hyslop maintains that if
electric burn of the mounth are seen and treated within the first 12H post burn,
there is a definite line of demarcation that allows immediate surgical tretament,
shortens healing time, and minimized the number of reconstructive procedures.
Secondary infection can he avoided if surgery is performed no later than 4 to 7
days post-injury.
3. mouth splints important
a. appliance is worn 24hrs a day for the first six months and 12hrs a day for
six more months.
Surgical options
Principles
1. reestablishing the intended location of the commissure,
2. excising the scar tissue
3. restore an adequate oral aperture
4. restore symmetry
5. re-establishing functional orbicularis oris sphincter

Orbicularis is step cut and rejoined thus effectively lengthened
Macrostomia


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Congenital cause
A lateral transverse orofacial cleft between the maxillary and mandibular
components of the first branchial arch.
caused by the failure of mesodermal migration or merging to obliterate the
embryonic grooves between the maxillary and mandibular swellings


1.
2.
3.
(prominences) during the fourth and fifth weeks of the embryonic phase of
gestation.
anatomical deformity includes
a. incomplete orbicularis oris ring on the side of the macrostomia with
bands of muscle parallel to the margins of the cleft
b. the upper lip orbicularis interdigitating and contiguous with the
zygomaticus
c. the lower lip orbicularis interdigitating and contiguous with risorius
Aims of surgery
accurate positioning without contractile scar of the oral commissure
reconstruction of a functional oral musculature
cheek skin closure with a minimal visible scar.
Positioning the commissure
 The midpoint of the upper lip is determined at a point between the two peaks of
Cupid’s bow.
 The length between the midpoint and the lateral end of the noncleft side is
transposed to the cleft side.
 In hemifacial microsomia, the reconstructed commissure should be positioned
slightly medially to provide balance to lesser facial tissue on the cleft side and the
reconstructed commissural position.
Orbicularis Repair
 orbicularis fibers of the upper lip are placed
anterior to those of the lower lip to simulate
the normal condition
 creates a normal contour
 sutured under adequate tension based on
where the commissure is going to be placed
 crucial in obtaining normal sphincter-like
function of the muscle
Skin Repair
 Straight line closure
o commissure of the mouth tends to be retracted inferolaterally due to
contracture (lateral migration)
o difficulty in adjusting the position of the commissure of the mouth.

Z Plasty
o Traditional method
o Z placed in line of nasolabial fold but fold difficult to ascertain in children
o Advantage of Z-plasty is that the position of the commissure of the mouth
can be adjusted to be the same as that on the unaffected side,
o Very visible scar especially with smiling

Double opposing Z plasty (Torkut PRS 1997)

W Plasy - Eguchi (Ann Plast Surg 2002)
o More effective than Z-plasty for scar outcome
o its effectiveness is not as great as that of Z-plasty when the aim is to
change the anatomic landmarks.