SURGICAL REPAIR OF THE UNILATERALLY CLEFT LIP

TECHNICAL BASIS


Normal Upper Lip

    *The high points of Cupid's bow are symetrical and situated along the horizontal axis.
    *The two philtral crests are parallel and equal in size.
    *The axis of symetry is perpendicular to the arc.
    *The cutaneomucuous lines ( A3-B4 ) are symetrical and of the same length.

Cleft Lip

    *The cleft is localized on the philtral column ( left ), and the medial side is hypotrophied.
    *Cupid's bow is lopsided, the left high point is split ( along 4 & 4' ) and is situated higher than its equivalent on the healthy side.
    *The axis of symetry is skewed towards the cleft side.
    *The wing of the nose is spread out.
    *The cutaneomucuous lines remain of the same length but are not symetrical.



 

A priory the plasty of such an anomaly can be remedied through the excision of the cleft
and of the distrophic tissues fringing it ( hatched areas in figs. 1a & 1b ).


Figure 1

Nevertheless the final result is not satisfactory , the arc is still not horizontal and the labial asymetry is still present : the cupidal tip ( 4') remains high. Suppressing this flaw has meaning only if the requirement to achieve facial symetry is taken into account.

 


Therefore rendering both sides of the of the lip symetrical requires lowering the cupidal tip on the cleft side to the point where it becomes level with the corresponding healthy side.
The solutions devised to this end are illustrated on the above canvas where the main reference points of the lip are takento be in the condition described above.
We will use the terms "medial side" and "lateral side" to refer to the two segments of the lip parted by the cleft.
Figure 2

 


Lowering the cupidal tip on the cleft side from a height "h" corresponding to
the denivellation can be achieved one of two ways:

Figure 3

*The first type of artifice transforms a curvilinear incision
-drawn from one extremity of the philtral crest to the other-into a rectilinear incision.
A slice of philtral tissue is then excised thereby exerting traction on the free end
of the lip ( hatched area 3a).

 

*The second type of artifice consists of cutting through the philtrum transversally,
the traction applied to the free end of the lip on the medial side
brings the arc to the horizontal position and results
in a triangularly shaped loss of tissue ( fig.4b).
The incision's length (5-x) corresponds to height (h).

Figure 4




                     

  In fact, the focus is on making the scar resulting from the surgery
     as unnoticeable as possible by hiding the philtral notch.

                    Figure 5

                                                 

The latter can be:
  *Single and distal, and present a right or reduced angle with the axis of symetry (5a-5b), or
  *Single and beneath the collumella, or
  *Double: the philtrum is notched starting from the the extremities of the philtral crest (5d).



 

Regardless of the procedure used, the gain in labial height comes at the cost of some amount of philtral tissue, which in turn will eventually have to be compensated for at the expense of the lateral side. In other words, getting the arc to lie along a horizontal axis takes precedence over allowances madeto correct the labial cleft. Therefore one ought to first concentrate on the philtrum prior to moving on to the lateral side the remodelling of whichis a function of what has been attained at the medial level.

These two distinct steps will be sketched out in a series of drawings which will present the methods used to bring Cupid's bow to lie horizontally.

 




Let us go back to figure 4;

*As a result of the excision of a crescent shaped area of philtral tissue,
the traction exerted on the free end of the medial side transforms the section slice from curvilinear to rectilinear thereby bringing Cupid's bow to lie along the horizontal axis. At this point the same procedure is also carried out on the lateral side to join the two sections. This method was devised by Rose & Thompson.

*One ought to bear in mind that the sacrifice of tissue made necessary by this procedure results in a narrowing of the philtrum.
*The second possible inconvenient is attributable to the rectilinear outline of the scar and the fact that it can retract following the surgery.


Let us go back to figure 5;

*The philtral notch (5-x) is made starting from the cupidal tip, the traction exerted on the free end of the medial side allows for the arc to be positionned horizontally. This leads to a loss of tissue (5-x-5) which is triangularly shaped and will eventually be filled in using a flap of tissue of the same dimensions cut out from the lateral side.

                                       

*Starting from point 4" a triangular flap (4"-5- 6) corresponding to the loss of philtral tissue is outlined. The delineation of the flap requires the excision of the tissue area located above it (hatched area in figure 5c). The flap is then freed and mobilized around its base (4"-6) until it is positionned into the philtrum.
*This principle of plasty is known as the triangular flap of rotation method, the original procedure is the work of Tennison .




Let us go back to figure 6b;

*The philtral notch is perpendicular to the axis of symetry.
The loss of tissue takes the shape of a right angle and
its hypotenuse represents the lip's deficit in height.

 



Starting from point 4' a right rectangular flap is drawn.
Its dimensions are equivalent to those of the area of philtral loss, and its mobilization
and repositionning obviously require a sacrifice of tissue (hatched area ).
This method developped by Lemesurier is a variant of Tennison's,
here the difference lies with with the complexity of the flap's outline and
the amount of labial tissue sacrificed.


* Making two cuts instead of one reduces the size of philtral tissue loss to the point where the scars resulting from the surgery are little noticeable. The length of each cut -at an angle with the vertical- does not exceed half  the deficit in height of the lip.

* Preparation of the two flaps necessitates the excision of a relatively more extended area of tissue.
This procedure devised by Skoog is in fact a variant of the triangular flap of rotation method;


*An incision is made beneath the columella and allows for the lowering of tip (4').

*The loss of tissue is compensated for by a flap cut into the lateral side by performing a transversal  counter-incision below the nostril.
*The lateral flap is then mobilized and forwarded into the area of tissue loss below the columella.

The advantage -among others- of this plasty devised by R. Millard and known as the " flap of advancement " method lies with the fact that it exploits the lateral side without incurring any sacrifice of tissue.


At the conclusion of this overview of the technical basis of the unilateral labial pasty
emphasis should be placed on the following points:

*The first step requires setting Cupid's bow along the horizontal axis.
*This procedure necessarily creates a loss of philtral tissue which is to be filled in from the previously modelled lateral side.
*Compensating for the sacrifice of philtral tissue requires a loss of tissue from the lateral side to the exception of the plasty relying on the flap of advancement method.

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