Soft tissue changes associated with double jaw surgery Alan C. Jensen, DDS, MS," Peter M. Sinclair, DDS, MSD, b and Larry M. Wolford, DDS c Dallas, Texas

The purpose of this study was to evaluate the amount, direction, and predictability of the soft tissue changes associated with simultaneous maxillary impaction and mandibular advancement surgery. The results suggested that the soft tissue responses were similar to those seen in single jaw procedures, with the exception of the changes seen in the nasolabial angle and in the area of the lower lip and chin. The type of soft tissue manipulation employed, in particular the use of the alar base cinch suture and V-Y closure techniques, were important factors in determining the response of the upper lip to the surgery, The maxillary soft tissues moved forward 90% of the hard tissue change and showed 20% shortening of the upper lip, with the changes in the nasolabial angle being due primarily to the degree of the maxillary rotation. A predictable progressive increase was seen in the horizontal movement of the mandibular soft tissues ranging from 73% of the hard tissue change at the lower lip to 100% at pogonion. The vertical movement of the mandibular soft tissue was greater than that of underlying hard tissues, particularly in the area of the lower lip as it was freed from the effects of the maxillary incisors. (AM J ORTHOO DENTOFAC 1992;101:266-75.)


I n the presurgical workup of any potential orthogn~fthic case, one of the prime concerns of both the orthodontist and the oral surgeon must be the final soft tissue p~ofile and the esthetic appearance of the patient. The relative anteroposterior positions of the nOse, lips, and chin must be evaluated, as must the vertical proportions of the soft tissue as well as the soft tissue contours, to produce the optimum postoperative profile. Initially, facial form was analyzed by various orthodontic investigators in attempts to relate the soft tissue profile to the underlying dentition. Researchers, who included Ricketts,1 Steiner,2 B urstone,3 and Holdaway, 4 soon recognized the need for, and therefore developed, cephalometric techniques to evaluate soft tissue that were separate from the established skeletal and dental analyses. Other investigators 51° have clearly demonstrated that, although the overlying soft tissue does not always reflect the underlying dentoskeletal pattern, there were some associations between the amount of tooth movement and the resultant soft tissue changes. The first surgical soft tissue studies were associated primarily with mandibular reduction procedures and atBased on a thesis by Alan C. Jensen submitted to the Department of Orthodontics, Baylor College of Dentistry, Baylor University, in partial fulfillment of the requirements for the degree of Master of Science. "Orthodontist, Salt Lake City, Utah. bAssociate Professor, University of North Carolina; formerly Associate Professor, Baylor College of Dentistry. ~Clinical Professor, Department of Oral and Maxillofacial Surgery, Baylor College of Dentistry. 8/1/26244


tempted to quantify the noticeable changes that occurred in the lower lip and chin in conjunction with the surgery. 1115It was reported that for each l mm of posterior mandibular skeletal movement, the soft tissue lip fell back 0.6 to 0.75 mm while the soft tissue chin moved posteriorly 0.9 to 1.0 m m . 16-17 Mandibular advancements have also been evaluated, and investigators have found that although the soft and hard tissue chins predictably advanced in a 1:1 ratio, the lower lip changes were more variable with soft/hard tissue ratios ranging from 0.38:1 to 0.75 : 1.17"8 The soft tissue changes associated with maxillary surgery have also been evaluated, and several investigators noted that as the maxilla was posteriorly displaced, the upper lip moved back, with ratios varying from 0.33 : 1 to 0.76: 1.19-22The wide range of soft tissue responses seen has been attributed to the type of soft tissue surgical manipulation employed. This is evident in the studies of soft tissue responses to maxillary advancement in which the early reports, which did not involve soft tissue manipulation, showed upper lip advancement ratios of from 0.4:1 to 0 . 8 2 : 1 . 23-27 In contrast, a more recent group of studies in which the V-Y closure technique and the alar base cinch suture procedure were employed demonstrated consistent soft/hard tissue ratios of approximately 0.9: 1.2~-3o Initial studies of the soft tissue responses to maxillary impaction noted that the nasal tip tended to turn up and that the nasolabial angle response was quite variable. 24,28 Simultaneously, other investigators 21'26

Volume 101

Number 3

Soft tissue changes associated with double jaw surgery 267

noted that although the upper lip tended to shorten by about 40% of the amount of incisor impaction, there was a tendency for the upper lip to also roll inward, creating a thinner and less esthetic vermillion border. More recent studies using the V-Y closure and alar base suture techniques have found minimal vermillion thinning and only about a 10% shortening of the upper lip. 28.29 To date, however, all this information has been collected from studies that have evaluated single jaw procedures carried out independently. When the clinician now wishes to predict the soft tissue responses to double jaw surgery, he is forced to use the single jaw data and attempt to extrapolate and correct them for bimaxillary surgery. As the data for soft tissue responses in bimaxillary surgery are extremely limited, it was the purpose of this study to analyze the soft tissue changes after simultaneous maxillary impaction and mandibular advancement with the objective of producing ratios that will allow for improved predictability of soft tissue responses in double jaw surgery cases.

Horizontal Reference Line (HRL)

Vertical Reference Line (VRL)


MATERIALS AND METHODS The sample used in this study consisted of 17 consecutive patients (15 females, 2 males) who were selected from the records of one surgeon (L. M. W.) and who met the following criteria: 1. The patients were nongrowing, and each had a diagnosis of vertical maxillary excess and mandibular deficiency. 2. Surgical treatment consisted of simultaneous LeFort I osteotomy with vertical maxillary impaction and bilateral sagittal split ramus osteotomy to advance the mandible. 3. No additional surgical procedures, such as genioplasty, rhinoplasty, or infraorbital augmentations, were performed. 4. The alar base cinch suture and the V-Y closure techniques were used in each case. 5. The patients had to have a natural dentition supporting the lips. 6. Records consisting of standardized lateral cephalograms that met the following criteria were available on all patients: (a) A preoperative radiograph taken within 1 week of surgery. (b) A postoperative radiograph taken a minimum of 9 months after surgery. (c) All radiographs taken in centric relation with lips in repose. (d) All hard and soft tissue landmarks clearly identifiable. The mean age of the sample at the time of surgery was 30 years 9 months, and the average follow-up period before the final records was 17.9 months. Each patient underwent a modified LeFort I procedure with the step osteotomy described

Fig. 1. Cephalometric landmarks digitized.

by Bennet and Wolford. 3~The maxillary segments were stabilized with rigid fixation consisting of Wurzburg or Champy miniplates and screws. 32The mandibular procedure consisted of a modified sagittal split osteotomy as described by Wolford et a1.,33 and fixation was achieved by the use of two or three bicortical lag screws on each side. For each patient the pretreatment and posttreatment lateral cephalometric headfilms were traced, and a total of 31 landmarks were identified (Fig. 1). These landmarks were then digitized with a backlit digitizing tablet (Hi-Pad Digitizing Tablet, Houston Instruments Inc., Austin, Texas) interfaced to a Data General minicomputer (Data General, Westboro, Mass.). A standard program (Analog Digital Systems, Albuquerque, N.M.) was used to collate the data and translate the X and Y coordinates into the desired angles and distances in relation to the horizontal reference line constructed 12° from the S-N line and the vertical reference line drawn through sella perpendicular to the horizontal reference line. These values were then transferred to a microcomputer (Heath/Ze. nith IBM compatible, Health Co., Benton Harbor, Mich.) for storage and later analysis by a standard statistical program (SYSTAT, Systat, Inc., Evanston, Ill.). A total of 47 cephalometric parameters were evaluated, consisting of 29 soft tissue measurements and 19 hard tissue measurements. Error analysis revealed that the mean combined error for the linear measurements was 0.17 mm with a standard deviation of 0.15 ram, whereas the angular measurements had a mean combined error of 0.28 ° and a 0.16 ° standard deviation. The overall mean, standard deviation, and range were calculated for each variable at both time periods. A positive


Am. J. Orthod. Dentofac. Orthop. March 1992

Jensen, Sinclair, and Wolford

Table I. Horizontal changes of maxillary hard and soft tissue landmarks Landmark

Mean +- SD (mm)


Range (mm)

Maxillary hard tissue A point Supradentale Maxillary incisor tip

+ 1.8 -+ 1.4 + 2 . 1 -!-- 1.8 + 1.9 +- 3.1

+ 0 . 2 to + 5 . 5 - 0 . 4 to + 5 . 9 - 2.5 to + 8.7

+ 1.2 + 1.3 + 2.0 + 1.5 +1.7

-0.4 0.0 -0.3 - 1.3 -2.4

Maxillary soft tissue


~- 1.8mm


/ _

/mm \ •

1.9mm'~' ' ~ - ~


'oo: ~ 78%

L o w e r nasal tip Subnasale Superior labial sulcus Labrale superius U p p e r stomion

--- 0.7 +- 0 . 8 -+ 1.6 +- 2.2 +-- 3.6

to to to to to

+2.4 +2.6 +4.7 +5.9 +11.2

+ = Anterior or inferior movement. - Posterior or superior m o v e m e n t s .


* Not Significantly Correlated Fig. 2. Percent horizontal maxillary soft tissue responses.

value was assigned to changes occurring in the anterior or inferior directions, whereas a negative value was assigned to changes occurring in the posterior or superior directions. The Pearson product' moment correlation coefficient was used to evaluate associations between parameters, with an r value of between 0.6 and 0.7 considered to represent a weak correlation, 0.7 to 0.8 a moderate correlation, and greater than 0.8 a strong correlation.

RESULTS Horizontal maxillary hard and soft tissue changes (Table I and Fig. 2) The hard tissue maxillary landmarks (A point, supradentale, upper incisal edge) moved anteriorly an average of 2.0 mm, with a range of 1.8 to 2.1 mm. The corresponding soft tissue landmarks (nasal tip, subnasale, superior labial sulcus, labrale superius, upper lip stomion) showed a gradual increase in response from a minimum of 1.2 m m of advancement at the nasal tip to a maximum of 1.7 mm at upper lip stomion. The only exception was at the superior labial sulcus, which demonstrated 2.0 m m of anterior change. The strongest correlations (Table II) were found between the anterior movement of the upper incisal edge and the three parameters representing the soft tissue upper lip: labrale superius r = 0.81, superior labial sulcus r = 0.78, and upper lip stomion r = 0.75. Thus the ratios (Table III) for the upper lip soft tissue response to maxillary advancement were 1 : 1 at superior labial sulcus, 0.8:1 at labrale superius, and 0.9:1 at upper lip stomion.

It was also noted that the amount of horizontal advancement of the maxilla correlated to the degree of upper lip shortening, with 2.0 mm of maxillary advancement at supradentale producing a 0.6 mm superior movement of labrale superius with a moderate correlation of r = 0.78 and a resultant 0.38:1 ratio. The upper lip length (subnasale to upper lip stomion) was shortened by an average of 0.8 mm and was weakly correlated (r = - 0 . 6 5 ) to the 1.8 m m of advancement at A point to produce a 0.44:1 ratio.

Angular maxillary soft-tissue changes (Table IV) Associations were also found between the amount of maxillary hard tissue advancement and the changes that occurred in the nasolabial angle. A mean increase of 1.2 ° was seen in the nasolabial angle, and this change was weakly correlated to both the 1.8 mm of advancement at A point (r = 0.61) and the 1.9 m m forward movement of the upper incisor (r -- 0.62) (Table II). In fact, the strongest correlations were seen between the rotational change of the anterior maxilla and the angulation of the philtrum (r = 0.75) and between the upper incisor angulation and the changes in nasolabial angle (r = - 0 . 6 8 ) . Although the nasolabial angle increased by an average of 0.65 ° for every 1 mm of maxillary advancement, it should be noted that there was a wide variety in the responses seen (range, - 7 . 9 ° to +9.7°); half of the patients showed increases, whereas the other half showed reductions after surgery. The angulation of the nasal dorsum to the horizontal reference line decreased by a mean of 2.6 ° as the nasal tip was raised during surgery. This change was weakly correlated to the amount of forward movement of the upper incisor (r = - 0 . 6 3 ) and produced a ratio of 1.37 ° of upturn of the nasal dorsum for every 1 mm of upper incisor advancement.

Soft tissue changes associated with double jaw surgery

Volume ]01 Number 3




o.,, o.. Io.,, o.. o.. 0.,, ~ii


o.~, o.o, o.,, !o.,, o.,, o.,, o.,J ~-il



Io.9, o.,, o.,~ o,, ~i~i

.o.~ ii!ii{

o.~, o.o,

0.62 0.81 0.M 0.1~ ~ i i


0.70 0.8~ 0.94 0.9~ ~

0. 6-POINT


0.74 0.90 0.97 0.9~



0.71 0.90 0.97 0.N

~!i !i~!i!o.. ~:~o.,, ~iio.





o.,, ,.,, ,., -1

o.o, o.09 o,,o,, ,.o,o,,o,~

~'::."il ~iloo7 ~{o,,



,.0, o.. o.. o.9,




!o.,, o.. o.. o.


o.. o.. o.. o.. o.

B!! o.. !~!~:i;o..




0.7( 0.3~ "0.01 ,0.73 0.7( 0,~ -0.0~


0.64 "0.~ "0.61 0.~ 0.741"0.6~ .0.67



@ FI~!I


Table II. Coefficients of simple correlations between soft tissue and hard tissue changes


o.7~ o.3, 1.0 0.79 0.~







0.09 0.0:



0.48 0,01 1.26 1.55 ~.":iil



0.42 0,72 1.1 1.3~ ~



0.37 0.63 0.96 1.2 i~i~!




o.3, o.,,o.. ,.o ;@





0.2t 0,10 018




0.82 1.12








0.80 1.09

13, 1 .








0.27 ~[~i

1,13 1.5 0.73 1.0


1.34 t.78 I).091 .19


1.64 2,19 1,09!I,4~


1.48 1.07 ~.g~ Jl.31

!~i °."

~!; Fii ~ ~! ~i ~i............. ~il~i ;:~!ii i~!!i '. i~!~~il ii!i~i~i:iiii~~ii: i !i!i~i~i i i{~:~'~,.~ilf~i .~ ,i~.~:~!i


0,g0 ),09 0.77


0.83 !0.63 0.71 I . ~

1,4 ~.40 3.73 4,50 ~!!~ ~.21 3.42 4.21 ~:i~{i

1.27 1.79 2.3~ 1.10 158



Table III. Soft/hard tissue ratios of significant correlations





Jensen, Sinclair, and Wolford

Am. J. Orthod. Dentofac. Orthop. March 1992

Table V. Vertical changes for maxillary hard and soft tissue landmarks Landmarks

Mean +- SD (mm)

Range (ram)

Maxillary hard tissue

1% 3.3mm 17

A point


Supradentale Upper incisal edge First molar tip

- 3 . 5 +- 2.5 - 3.2 -- 2.7 - 2 . 2 --_ 1.6

--_ 2.1

- 8 . 3 to - 0 . 5 - 7 . 8 to - 0 . 2 - 8.9 to + 0.6 - 6 . 1 to + 0 . 1

Posterior nasal spine

- 1.1 + 2.3

- 6 . 5 to + 1.5

L o w e r nasal tip Subnasale Superior labial sulcus

-0.7 -0.6 -0.6

± 0.8 _+ 0.6 --_ 0.9

- 2 . 3 to + 0 . 8 - 1 . 4 to + 0 . 8 - 2 . 1 to + 0 . 6

Labrale superius Upper lip stomion

- 0 . 8 + 1.1 - 1.2 _ 1,5

- 2 . 5 to + 0 . 8 - 3.7 to + 1.6

Upper lip length (SN-ULS)



Maxillary soft tissue

--_ 1.9


+ = Anterior or inferior movements. - = Posterior or superior movements.





No Significant Correlations

3. Percent vertical maxillary soft tissue responses.

Table IV. Angular changes for selected hard and

soft tissue parameters Landmark

J Mean ± SD (degrees)

Nasal dorsum to H R L Coiumella to H R L Philtrum to H R L Nasolabial angle Occlusal plane to H R L Mandibular plane to H R L Anterior maxilla to H R L


-2.6 + 1.4 +0.1 + 1.2 -2.2 - 2.4 -0.1

± --_ _ _+ ± ± ±

1.5 2.5 7.2 6.4 6.5 3.1 7.7

Range (degrees) -5.3 - 3.5 -12.7 -7.9 - 19.2 - 9.0 - 17.5

to to to to to to to

+0.4 + 4.6 +11.9 +9.7 + 8.1 + 3.8 + 14.0

Horizontal reference line.

+ = Increase in angulation. - = Decrease in angulation.

Vertical maxillary hard and sof tissue changes

(Table V and Fig. 3) The vertical impaction of the anterior maxilla (A point, supradentale, upper incisal edge) averaged 3.4 ram, with a range of 3.2 to 3.5 mm. Most of the corresponding maxillary soft tissue landmarks (lower nasal tip, subnasale, superior labial sulcus, labrale superius) showed a uniform 0.6 to 0.8 mm of superior change with a mean of 0.7 mm, The only exception was upper lip stomion, which moved superiorly by 1.2 ram. Therefore upper lip stomion moved superiorly an average of 0.4 mm more than labrale superius, effectively reducing the vermilion thickness of the upper lip. The strongest correlations to the vertical maxillary impaction were seen between A point and lower nasal

tip (r = 0.84), superior labial sulcus (r = 0.79), and subnasale (r = 0.74), as well as between supradentale and superior labial sulcus (r = 0.82) (Table iI). Thus the ratio of soft tissue change to hard tissue change at A point was 0.21:1 for lower nasal tip and 0.18:1 for both superior labial sulcus and subnasale, whereas the superior labial sulcus to supradentale ratio was 0.17 : 1 (Table lII). Moderate correlations were also noted between the vertical maxillary impaction and the vertical changes of the mandibular soft tissues. The upper incisor impaction showed correlations to inferior labial sulcus (r = 0.78) and soft tissue pogonion (r = 0.72). Although these correlations were an incidental finding occurring as a result of mandibular autorotation, it is interesting to note that the mandibular soft tissue moved superiorly approximately the same amount as the maxillary impaction (i.e., a 1:1 ratio). The 2.6 ° uptum seen in the nasal dorsum was found to be correlated to the degree of maxillary incisor impaction (r = 0.72) producing a ratio of 0.81 ° of nasal dorsum flattening to each 1 mm of incisal edge impaction. Mandibular hard and soft tissue changes (Table Vl

and Fig. 4) The mandibular hard tissue landmarks demonstrated a gradual increase in the amount of anterior movement ranging from 6.5 mm at the mandibular incisal tip to 9.9 mm at pogonion reflecting the upward and forward rotation of the mandible that occurred as a result of the maxillary impaction. The accompanying soft tissue landmarks also exhibited a gradual increase in their

Volume 101 Number 3

Soft tissue changes associated with double jaw surgery 271 tt---.-~ 6.5m m ....-..,=__~ 42%*

1 lO%

.I7 % W -%




_J * -- Not Significantly Correlated

Fig. 4. Percent horizontal mandibular soft tissue responses.

Table VI. Horizontal changes of mandibular hard and soft tissue landmarks

I Mean ± SD (mm )

Range (mm )

Mandibular incisor tip Infradentale

+ 6.5 ± 2.6 + 7 . 4 ± 3.4

+ 2.0 to + 11.3 + 3.9 to + 14.0

B point Pogonion

+ 8 . 4 ± 4.2 + 9 . 9 ± 5.0

+ 3 . 6 to + 1 6 . 1 + 3 . 5 to + 1 9 . 1

L o w e r stomion Labrale inferius Inferior labial sulcus

+ 3 . 1 ± 3.7 + 5 . 3 ± 3.1 + 8 . 2 ± 4.2

- 2 . 5 to + 1 0 . 4 + 1.3 to + 11.7 + 3 . 6 to + 16.8

Pogonion soft tissue

+ 10.1 -*- 4.8

+ 5.4 to + 20.4

Landmark Mandibular hard tissue

Table VII. Vertical changes of mandibular hard and soft tissue landmarks Landmark

I Mean ± SD (mm )

Range (mm )

Mandibular hard tissue

Mandibular soft tissue

L o w e r incisal edge

- 3.8 ± 3.0

- 9.7 to + 1.2



± 2,6

- 8 . 4 to + 0 . 9

B point Pogonion

-2.6 -2.9

± 2.5 ± 2.7

- 6 . 6 to + 1 . 0 - 7 . 1 to + 1 . 0

L o w e r lip stomion Labrale inferius

-4.3 -5.7

± 3.8 ± 4.2

-ll.2to +2.2 - 14.0 to - 0 . 1

Inferior labial sulcus Pogonion soft tissue

-2.8 -3.8

± 3.8 ± 3.1

- 9 . 9 to + 5 . 1 - 1 0 . 4 to + 1 . 4

Mandibular soft tissue

+ = Anterior or inferior m o v e m e n t s . -

Fig, 5. Percent vertical mandibular soft tissue responses.

= Posterior or superior m o v e m e n t s .

mean anterior movement from 3.1 mm at lower lip stomion to 10.1 m m at soft tissue pogonion. Strong correlations were found between virtually all the hard and soft tissue landmarks ranging from r = 0.81 to r = 0.98 (Table II). The only exception was for lower lip stomion that demonstrated weak correlations to the mandibular hard tissue landmarks ranging from r = 0.62 to r = 0.74. This difference might be attributed to the freeing of the lower lip previously trapped by the protrusive upper incisors. Thus the soft/hard tissue ratios increased from 0.48:1 between lower lip stomion and lower incisor, through 0.72:1 for labrale inferius to infradentale, and 0.98:1 for inferior labial sulcus to B point to 1 : 1 for soft to hard tissue pogonion (Table III). Vertical mandibular hard and soft tissue movements (Table VII and Fig. 5) The mandibular hard tissue landmarks (lower incisal edge, infradentale, B point and pogonion) moved superiorly an average of 3.1 mm, with a range from 2.6 to 3.8 mm. The lower incisal edge moved vertically the greatest amount, 3.8 mm, and showed a strong

+ = Anterior or inferior m o v e m e n t s . - = Posterior or superior m o v e m e n t s .

correlation with the 4.3 mm vertical movement of lower lip stomion (r = 0.81, ratio = 1.13 to 1) and to the 5.7 mm movement of labrale inferius (r = 0.82, ratio = 1.5:1) (Tables II and III). Similarly infradentale, which underwent a 3.2 mm vertical move, was also strongly correlated to the changes at lower stomion (r = 0.78, ratio = 1.34:1) and to labrale inferius (r = 0.80, ratio = 1.78:1). These ratios reflecting greater vertical movement of the soft tissues than the underlying hard tissues are also probably due to the previously mentioned upward and backwards rotation of the lower lip as it was freed from the upper incisor. The 2.6 mm upward movement at B point was correlated (r = 0.79) with the 2.8 mm movement of inferior labial sulcus with a soft/hard tissue ratio of 1.08: 1. Similarly the 2.9 mm upward change in pogonion was correlated (r = 0.89) with 3.8 mm elevation of soft tissue pogonion to produce a 1.31 : 1 ratio. Soft tissue thicknesses (Table VIII) The upper lip thinned an average of - 0 . 6 mm at the superior labial sulcus and - 1.5 mm at labrale superius when the maxilla was impacted an average of


Jensen, Sinclair, and Wolford

Am. J. Orthod. Dentofac. Orthop. March 1992

Table VIII. Soft tissue thickness changes Measurement

Mean +- SD (ram)

Superior labial sulcus Labrale superius Labrale inferius Inferior labial sulcus Pogonion soft tissue Menton soft tissue

- 0 . 6 +_ 1.5 - 1 . 5 --- 2.0 - 3 . 9 +-- 1.9 - 0 . 2 +_ 1.0 + 0 . 4 _+ 0.9 + 0 . 2 -2-- 1.3

Range (ram) - 3 . 8 to - 5 . 0 to - 7 . 8 to - 2 . 1 to - 1 . 5 to -l.6to

+ 1.6 +1.3 -0.2 +1.7 +1.7 +2.6

+ = Thickened. - = Thinned.

3.4 mm and advanced an average of 2.0 mm. The mandibular soft tissues showed minimal changes with the exception of labrale inferius, which showed an average reduction of 3.9 mm and again was reflective only of the changes in lower lip shape after its release from under the influence of the maxillary incisors. No significant correlations were noted between the changes in soft tissue thickness and any of the surgical changes (Table II). However, a moderate correlation (r = 0.77) was noted between the 0.2 mm of reduction seen in the tissue thicknesses of the lower lip and its initial presurgical thickness of 11.3 mm. When the sample was brokendown into subsets with thin lips (n = 7, x = 10.2 mm, range 9.0 to 11.5 mm) and thick lips (n = 10, x = 12.2 mm, range 11.6 to 13.0 mm), it was noted that although the thin-lip group exhibited insignificant changes, the thick-lip group showed an average of 1 mm of soft tissue thinning, reflecting a 0.13 mm thinning of the lip for each 1 mm of mandibular advancement. DISCUSSION Overall, the data from this study suggested that when simultaneous two jaw surgery was performed to correct vertical maxillary excess and mandibular deficiency, there was a tendency for the soft tissue responses to be similar to those seen in single jaw procedures with the exception of the changes seen in the nasolabial angle and the vertical movement of the lower lip and chin. With an average 2 mm advancement and 3.4 mm impaction of the maxilla, there was a tendency for the base of the nose (subnasale and nasal tip) to advance about two thirds of the amount of anterior movement of A point, whereas the free end of the upper lip showed a change that averaged about 90% of the maxillary advancement (Fig. 2). However, the responses of the base of the nose and the subnasale area after surgery have historically been quite unpredictable 26'27'3° and once again did not show any strong correlations to the hard tissue changes in this study. This may be due in

part to variations in amount of occlusal plane rotation that occurred during surgery and the alar base manipulation or surgical handling of the anterior nasal spine. With regard to the upper lip changes, the maxillary soft tissue studies can be divided into two groups: (1) those using surgical soft tissue manipulation (i.e., alar base cinch suture and V-Y closure) and (2) those without any soft tissue-altering procedures. The 90% anterior upper lip movement seen in this study was similar to the findings of other studies in the first group that also showed a 70% to 90% upper lip response. 29'3° In comparison, the second group of older studies in which no soft tissue manipulation was done found that the anterior soft tissue changes ranged from 40% to 60% of the hard tissue changes. ~7,23'25The difference between the two groups demonstrates the importance of determining the surgical technique to be used by the surgeon, so that an accurate prediction tracing can be produced. For example, if the surgeon is using an alar base cinch suture to prevent an increase in alar base width, 34 the clinician should plan on approximately 80% to 90% forward movement of the upper lip. However, if the nose is already narrow, the alar base suture may not be desirable. In this case a more conservative upper lip change in the range of 60% should be used in the prediction tracing. An additional factor complicating the upper lip prediction is the effect of rotational changes in the maxilla. A strong correlation (r = 0.89) was noted between the occlusal plane rotation and the horizontal changes in the maxillary incisor position, which, in combination with the correlation (r = 0.70) seen directly between the amount of maxillary rotation and upper lip response, suggests a significant interaction. It appears that as the occlusal plane is rotated upward and forward and the upper incisor is flared, additional support is created for the upper lip, thereby altering the soft tissue response ratio. Therefore if an occlusal plane rotation is to be carried out as part of the surgical treatment plan, the clinician needs to be aware of the differential horizontal movements that will occur between A point and the maxillary incisal edge and should plan the predicted upper lip movement accordingly. The data from this study also suggested that changes in the angulation of the philtrum had the greatest influence on the nasolabial angle (r = 0.92). Although the mean change for the philtrum was only 0.1 °, there was a mean reduction of 5.6 ° in the nasolabial angle in the cases in which the maxilla and hence the philtrum rotated downward and backward and a mean increase of 6.5 ° in the nasolabial angle where the maxilla was rotated upward and forward (r = 0.75) (Fig. 6). Overall, it appeared that there was an increase of 0.65 ° in the nasolabial angle for each 1 mm of maxillary

Volume 101 Number 3

advancement. The nasal dorsum demonstrated an elevation (flattening) of 1.3 ° for each 1 mm of maxillary advancement and an elevation of 0.81 ° for each 1 mm of maxillary impaction. These changes were consistent with the findings of other researchers and confirmed their suggestions that the angular changes in maxillary hard tissue landmarks had considerable influence on the final soft tissue responses. 19.21,23,26They also imply that in future studies upper incisal angulation should be carefully evaluated to see whether it can provide correlations of even greater clinical significance for the upper lip. The vertical movements of the nose and upper lip were moderately predictable (r = 0.74 to 0.84) and exhibited a uniform superior movement of 20% of the corresponding maxillary hard tissue change (Fig. 3). The only exception was at upper lip stomion, which moved superiorly 38% of the amount of upper incisor impaction and did not appear to be correlated with the hard tissue change. This additional vertical movement of stomion, which has been reported in other studies 2°'2j'26'27 and results in thinning of the vermilion border of the upper lip, has been attributed to the soft tissue surgical technique employed. 21'~8It was thought that the use of the V-Y closure and the alar base cinch suture would minimize this change, but, unlike the findings of Schendel and Williamson, 28 these procedures appeared to have little effect in this study. Thus a careful assessment of the likely vertical changes in the upper lip is critical when one is planning for the correct amount of incisor exposure at rest in vertical maxillary impaction cases. For example, if a patient has 6 mm of upper incisor exposure and a toothto-lip relationship of 3ram is desired, then taking into account the expected 20% shortening of the soft tissues, a 4 mm maxillary impaction will be required. If, however, a maxillary advancement is also required, then the likelihood that the upper lip will usually shorten by 0.3 8 mm for each 1 mm of maxillary advancement may increase the amount of vertical impaction required. The changes seen in the anteroposterior positions of mandibular soft tissues showed strong correlations to the underlying hard tissues with the soft/hard tissue ratio showing a progressive increase from 42% at lower lip stomion up to 100% at soft tissue pogonion (Fig. 4). The 1 : 1 ratio of changes seen with the soft tissues of the labiomental fold and chin are similar to reports by other researchers and probably represent the tight attachment of these tissues to their underlying skeletal bases. ~7,18Although previous reports have stressed the unpredictability of the lower lip changes, 16-18this study, for the first time, showed significant correlations (r = 0.81 to 0.90) at labrale inferius with a 0.72:1 soft/hard tissue ratio. As the mandible was advanced and rotated upward

Soft tissue changes associated with double jaw surgery


Fig. 6. Changes in the nasolabial angle resulting from surgical anterior maxillary rotation.

and forward in this study, the soft tissue landmarks overlying the lower incisor, B point, and pogonion moved superiorly more than their underlying hard tissues. The slightly greater than 1:1 ratios seen in the soft tissue movements over B point and the chin (1.1:1 and 1.2: l, respectively, Fig. 5) were in contrast to other studies that have shown soft tissue responses in the 0.8 to 0.93 range but did not evaluate the particular surgical combination used in this study. 16'17'21 The changes seen in the lower lip can be explained by its release from the influence of the upper incisor producing a rotation up and back around the inferior labial sulcus. As a result, lower lip stomion moved superiorly 110% of the surgical change and labrale inferius moved 150% of the surgical change. With the exception of some recent data from Proffit and Phillips, 35 which also show lower lip soft tissue ratios greater than 1 : 1, there is little information in the literature regarding lower lip changes, and it is not clear whether these findings should be confined to cases with lower lip entrapment or are generally applicable to double jaw surgery cases. In general, on the basis of the data from this study, a clinician conducting soft tissue prediction for a combined maxillary impaction and mandibular advancement might find the following guidelines useful. As the


Jensen, Sinclair, a n d Wolfe, re1

maxilla is impacted and advanced, _the upper lip will advance 90% of the underlying hard tissue change and m o v e superiorly 20% o f the hard tissue m o v e m e n t . In addition, the nasolabial angle will change by an a m o u n t equal to about 60% of the rotation of the anterior maxilia. As the mandible is advanced, the lower soft tissues will advance in a graduated fashion, ranging f r o m 72% at the l o w e r lip to 100% at soft tissue pogonion. Vertically, the mandibular soft tissue will m o v e superiorly approximately 120% o f the hard tissue changes with the exception of the l o w e r lip, which may s h o w up to 150% of the hard tissue change.

CONCLUSIONS l. Overall, the soft tissue responses to simultaneous two j a w surgery w e r e similar to those seen in single j a w procedures with the exception of the changes in the nasolabial angle and in the area of the l o w e r lip and chin. 2. The type o f surgical soft tissue manipulation e m p l o y e d was an important factor in the determination o f the upper lip r e s p o n s e to the maxillary i m p a c t i o n and advancement. 3. Ch~inges in the nasolabial angle angle w e r e primarily due to rotational changes of the underlying hard tissues rather than to their anteroposterior or vertical movements. 4. The maxillary soft tissues m o v e d forward 90% o f the hard tissue c h a n g e and showed a 20% shortening o f the upper lip. 5. There was a predictable progressive increase in the horizontal m o v e m e n t o f the mandibular soft tissues, ranging f r o m 72% o f the hard tissue change at the l o w e r lip to 100% at pogonion, 6. The mandibular soft tissues m o v e d superiorly by greater amounts than their underlying hard tissues, particularly in the area o f the l o w e r lip as it was freed f r o m the effects of the m a x i l l a r y incisors.

REFERENCES 1. Ricketts RM. Planningtreatmentonthebasisofthe facialpattern and an estimate of its growth. Angle Orthod 1957;27:14-37. 2. Steiner CC. Cephalometrics in clinical practice. Angle Orthod 1959;8-29. 3. Burstone CJ. Lip posture and its significance in treatment planning. AM J ORTHOD1967;53:262-84. 4, Holdaway RA. A soft tissue cephalometric analysis and its use in orthodontic treatment planning. Part I. AM J ORTHOD 1983;84:1-28. 5. Downs WB. Analysis of the dentofacial profile. Angle Orthod 1956;26:191-212. 6. Subtelny JD. A longitudinal study of soft tissue facial structures. AM J ORTHOD1959;45:481-507. 7. Rudee DA. Proportional profile changes concurrent with orthodontic therapy. AM J ORTHOD1964;50:421-33.

Am. J. Orthod. Dentofac. Orthop. March 1992

8. Bloom LA. Perioral profile changes in orthodontic treatment. AM J ORTHOD1961;47:371-9. 9. Hershey HG. Incisor tooth retraction and subsequent profile change in postadolescence female patients. AM J ORTHOO 1972;61:45-54. 10. Jacobs JD. Vertical lip changes from maxillaryincisorretraction. AM J ORTHOD1978;74:396-404. 11. Knowles CC. Changes in the profile following surgical reduction of mandibular prognathism. Br J Plast Surg 1965;18:432-4. 12. Aaronson SA. A cephalometric investigation of the surgical correction of mandibular prognathism. Angle Orthod 1967;37: 251-6. 13. Fromm B, Lundberg M. The soft tissue facial profile before and after surgical correction of Mandibular Protrusion. Acta Odontol Scand 1970;28:157-77. 14. Hamula W. Surgical alteration of muscle attachments to enhance esthetics and denture stability, AM J ORTHOD1970;57:327-67. 15. Bjork N, Eliasson S, Wictorin L. Changes in facial profile after surgical treatment of mandibular protrusion. Scan J Plast Reconstr Surg 1971;5:41-6. 16. Hershey HG, Smith LH. Soft tissue profile change associated with surgical correction of the prognathic mandible. AM J ORTROD 1974;65:485-502. 17. Lines PA, Steinhauser WW. Soft tissue changes in relationship to movement of hard structures in orthognathic surgery: a preliminary report. J Oral Surg 1974;32:891-6. 18. Quast DC, Biggerstaff RH, Haley JV. The short-term and longterm soft tissue profile changes in accompanying mandibular advancement surgery. AM J ORTHOD1983;84:29-36. 19. Bell WH, Dann JJ, III. Correction of dentofacial deformities by surgery in the anterior part of the jaws: a study of stability and soft tissue changes. AM J ORTHOD1973;64:162-87. 20. Schendel SA, Eisenfeld JH, Bell WH, Epker BN. Superior repositioning of the maxilla: stability and soft tissue osseous relations. AM J ORTHOD1976;70:663-74. 21. Radney JR, Jacobs JD. Soft tissue changes associated with surgical total maxillary intrusion. AM J ORTHOD1981 ;80:191-212. 22. Nadkarni PG. Soft tissue profile changes associated with orthognathic surgery for bimaxillary protrusion. J Oral Maxillofac Surg 1986;44:851-4. 23. Dann JJ, III, Fonesca RJ, Bell WH. Soft tissue changes associated with total maxillary advancement: a preliminary study. J Oral Surg 1976;34:19-23. 24. Freihofer HPM. The lip profile after correction of retromaxillism in cleft and non-cleft patients. J Maxillofac Surg 1976;4:13641. 25. Araujo A, Schendel SA, Wolford LM, Epker BN. Total maxillary advancement with and without bone grafting. J Oral Surg 1978;36:849-58. 26. Mansour S, Burstone C, Legan H. An evaluation of soft tissue changes resulting from LeFort II maxillary surgery. AMJ ORTHOD 1983;84:37-47. 27. Rosen HM. Lip-nasal aesthetics following LeFort I osteotomy. Plast Reconstr Surg 1988;81:171-9. 28. Scfiendel SA, Williamson LW. Muscle reorientation following superior repositioning of the maxilla. J Oral Maxillofac Surg 1983;41:235-40. 29. Wolford LM, Hilliard FW, Dugan DJ. Surgical treatment objective: a systematic approach to the prediction tracing. St. Louis: CV Mosby, 1985. 30. Carlotti AE, Aschaffenburg PH, Schendel SA. Facial Changes Associated with Surgical Advancement of the lip and Maxilla. J Oral Maxillofac Surg 1986;44:593-6.

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Soft tissue changes associated with double jaw surgery

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31. Bennett MA, Wolford LM. The maxillary step osteotomy and Steinmanpin stabilization.J Oral MaxillofacSurg 1985;43:30711. 32. ChampyM, Lodde JP, Schmitt R, Jaeger JH, Muster D. Mandibular osteosynthesisby miniaturescrewed plates via a buccal approach. J Maxillofac Surg 1978;6:14-21. 33. Wolford LM, Bennett MA, Rafferty CG. Modificationof the mandibularramus sagittal split osteotomy. Oral Surg Oral Med Oral Pathol 1987;64:146-55. 34. GuymonM, CrosbyDR, WolfordLM. The alar basecinch suture to control nasal width in maxillary osteotomies. Int J Adult Orthod Orthognath Surg 1988;3:89-96.


35. Proffit WR, Phillips C. Adaptationsin lip posture and pressure followingorthognathicsurgery. AMJ ORTHODDENTOFACO~THOP 1988;93:294-302.

Reprint requests to: Dr. Peter M. Sinclair Department of Orthodontics School of Dentistry Universityof North Carolina Chapel Hill, NC 27599-7450

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Soft tissue changes associated with double jaw surgery.

The purpose of this study was to evaluate the amount, direction, and predictability of the soft tissue changes associated with simultaneous maxillary ...
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