Functional genioplasty in growing patients

www.sylvainchamberland.com
Functional Genioplasty in
Growing Patients
Edward H.Angle Society
41st Biennal Meeting
Pasadena
 
September 25-29, 2015
Langham Hotel

©sylvainchamberland.com
World Tour
•Angle East meeting, Paris, April 2014
•AAO, 114th Annual Session,  
New Orleans, April 2014
•UNC, Chapel Hill, June 2014
•SOBOR, Bruxelles, Jan. 2015
•18èmes JOF, Paris. Nov. 2015
•Alumni University of Montreal, Jan. 2016

©Dr Sylvain Chamberland
Scenario
L.-P.Tr June 94
Baseline
L.-P.Tr Jan 96, RPE HPHG, Intrusive arch
Progress
L.-P.Tr June 97, class I relationship
Final

•Unfavourable vertical growth
•A-P Chin deﬁciency
•Vertical excess of LAFH
•Lip incompetency
• How many of you would
recommend a genioplasty?
• What would happen if you
advance the chin in this 13
years old boy?
• What would happen if you do
not?

Inferior Border Osteotomy
•Isolated procedure or in combination with other maxillo-mandibular osteotomies
✦ Most common for AP deﬁciency or vertical excess
✓ Simultaneous advancement & vertical reduction
✦ Set back (usually not as successful because of aesthetic problems)
TRAUNER
R,
and
OBWEGESER
H.
The
surgical
correction
of
mandibular
prognathism
and
retrognathia
with
consideration
of
genioplasty.
II.
Operating
methods
for

microgenia
and
distoclusion.
Oral
Surg
Oral
Med
Oral
Pathol.
1957,
Sep;10(9):899-‐909.
Mortise & RF Wire Fixation Rigid Fixation

Functional Genioplasty
•Defined by Precious and Delaire
•Provide beneficial change in the lip function
•Helps to obtain lip competency at repose
Precious DS, Delaire J.Correction of anterior mandibular vertical excess: the functional genioplasty. Oral Surg Oral Med Oral Pathol. 1985
Mar;59(3):229-35.
Proffit WR, Phillips C. Adaptations in lip posture and pressure following orthognathic surgery.Am J Orthod 1988; 93:294-304

Alloplastic Chin Augmentation
•Alloplastic material does not integrates with bone
•May drift off the chin
•Muscle and soft tissue ➜ pressure  
➜ bone resorption underneath
•Do not permit vertical reduction
•May cause ptosis of the lower lip
•Poor aesthetic and functional outcome

•When ortho treatment has created md
incisor protrusion
•Improving relationship between the
chin and mandibular incisor
(Holdaway ratio)
✦ Might be beneﬁcial to avoid
mucogingival problem
✦ Would improve facial proﬁle
•One way to do that
✦ Advance the chin rather than
retracting the incisors
CaRo15y4m CaRo17y3m

CaRo15y4m CaRo17y3m

•Helpful when improvement in occlusion was achieved by tooth
movement with minimal or unfavourable md growth
K.D. 16y3m 05-04
K.D. 16y9m 12-04 K.D. 18y6m 09-06

Additional beneﬁts
•Facial appearance can be a serious psychosocial handicap, even
early in life
•Functional genioplasty
✦ Means to improve facial aesthetics
✦ Function
✦ Stability in conjunction with orthodontic treatment
McGregor FC. Facial disﬁgurement, problems and management of social interactions and implications for mental health.Aesthetic Plastic Surg 1990; 14:249-257.

Rationale for the study
•Number of publications on genioplasty
✦ Only a few have data for this procedure in adolescents
✦ No good recent data on bone remodeling following genioplasty in
growing and non-growing patients
✦ No study include follow-up of a control group who were evaluated as
potentially beneﬁting from genio but rejected it
•Optimum age has been somewhat controversial

Positive Psychosocial Reaction
•To improved facial appearance would suggest earlier treatment for
severely affected patient
•Concerns about possible negative effects on growth and decreased
stability would be the major reason for waiting until little or no
growth remained
McGregor FC. Facial disfigurement, problems and management of social interactions and implications for mental health.Aesthetic Plastic Surg 1990;
14:249-257.
Phillips C, Proffit WR. Psychosocial aspects of dentofacial deformity and its treatment. in Proffit WR,White RP Jr, Sarver DM (eds.), Contemporary
Treatment of Dentofacial Deformity. St Louis, Mosby, 2003.
Polido WD, de Clairefont RL, Bell WH. Bone resorption, stability, and soft-tissue changes following large chin advancements. J Oral Maxillofac Surg
1991; 49:251-6.

Osseous Remodeling after
Genioplasty
•Martinez et al, JOMS 1999
✦ Better regeneration in the symphysis thickness in patient
younger than age 15 than in older non growing individuals
l 75% regeneration of the lingual gap; 92% regeneration of symphysis width
Par. Jo. 12Y 4M 12Y 5M 14Y 4M
Martinez,Turvey & Profﬁt, Osseous remodeling after inferior border osteotomy for chin augmentation: an indication for early surgery,
JOMS 1999, Oct;57(10);1175-80

Impact of genioplasty on mandibular growth
during puberty
•Frappier et al, Int. Orthod. 2010 & 2011
✦ Early genioplasty could improve mandibular growth direction
✦ Might increase nasal breathing because of improved lip function
•Weakness:
✦ Sample too small and diverse for broad generalization
✦ No control group + changes pregenio and immediate postgenio not
evaluated
Frapier L, Jaussent A,Yachouh J, Goudot P et al. Impact of genioplasty on mandibular growth during puberty, Int. Orthod. 2010, Dec;8(4);342-59
Frapier L, Picot M-C, Gonzales J, Massif L et al.Ventilatory disorders and facial growth: beneﬁts of early genioplasty. Int Orthod 2011; 9:20-41

Isolated Genioplasty
•Requires general anesthesia, but not overnight
hospitalization
•Day-op procedure
•Usually part of a larger orthognathic surgery plan because
medical insurance almost never cover the cost in an
isolated procedure
•Medical coverage is provided

Aim of the study
•Clarify the optimal time for functional genioplasty from evaluation of
✦ The pattern of bone remodeling at the chin
✦ The pattern of postsurgical stability in growing and non-growing
patients

Cephalometric Analysis
Time Point
• Experimental Group
✦ T1- 2-3 months prior to
genioplasty (10,11± 13,82
weeks)
✦ T2- 1 month post surgery
(4,57 ± 3,82 weeks)
✦ T3- 2 years post surgery
(111,04 ± 29,91 weeks) 
 
• Control Group
✦ T2- End of orthodontic
treatment
✓ Because there was no surgery, there was no T1
equivalent to the experimental group. For
consistency in the stats analysis, T2 data are
same as T1.
✦ T3- 2 years follow-up (117,42
± 27,34 weeks after T1)

Sample Characteristics
•Patient Sample
✦ Retrospective data (June 92-Dec. 15) from 54 patients who underwent isolated
advancement genioplasty to achieve lip competency as an adjunct to orthodontic
treatment
✓ Initial sample 59, 5 were excluded (missing rx)
•Control
✦ 23 patients with similar morphology who were offered genioplasty in conjunction with their
treatment but declined it
✦ 5 patients of the control group joined the surgery group because they accepted the
genioplasty 2 years or more after ortho tx

• Groups are similar relative to % of female
Age
10,00
14,80
19,60
24,40
29,20
34,00
Age
14,31
28,65
16,65
14,00
Group 1 (<15) 32% female
Group 2 (15-19) 44% female
Group 3 (>19y) 40% female
Group 4 Control 39% female
Group N % female
Gr 1 < 15yr 28 32 %
Gr 2 15-19 16 44 %
Gr 3 > 19 10 40 %
Gr 4 Control <15y 23 39 %

•Groups are similar and comparable regarding FMA and symphysis
thickness
FMA
25,00
28,40
31,80
35,20
38,60
42,00
FMA
31,97
34,76
32,46
34,06
Group 1 (<15)
Group 2 (15-19)
Group 3 (>19y)
Group 4 Control
Symphysis thickness
0,00
2,30
4,60
6,90
9,20
11,50
Age
8,84
7,998,14
8,39

•Experimental groups are similar and comparable relative to genial advancement and vertical
reduction
•Changes of control growth express horizontal and vertical growth in 2 years (T3T2)
Horizontal changes at Pg
∆Pg Horiz.
-1,00 0,67 2,33 4,00 5,67 7,33 9,00
2,67
5,25
5,88
6,45
Vertical change at Me
-9,20
-6,50
-3,80
-1,10
1,60
4,30
7,00
∆ Me vertical
-4,46
3,833,53
2,93
Group 1 (<15)
Group 2 (15-19)
Group 3 (>19y)
Group 4 Control

Surgical Procedure
•General anesthesia, H. E.-J.
•Technique:
✦ Describe by Precious, Armstrong & Morais
•Anterior and superior repositionning, slide into its new position
•Slice of bone might be removed prn to increase vertical reduction
•Wire osteosynthesis: 3 transosseous double strand 28 gauge SS
✦ (Only 5 had screw ﬁxation, none were removed)
Precious DS,Armstrong JE, Morais D.Anatomic placement of ﬁxation devices in genioplasty. Oral Surg Oral Med Oral Path 1992; 73:2-8.

• Dehiscence over the roots secondary to
root prominence, lip incompetency and
muscular hyperactivity of the chin
• Surgical tips
✦ Raise full thickness ﬂap over the roots to fully
expose the buccal plate until the coronal portion
of the crest can be seen
✦ Closure of the muscular plane (mentalis
muscle) will leave some void ﬁlled by blood clot
✦ This will allow bone apposition over the roots
down to the advanced genial segment that will
remodel (if lip competency has been achieved by the osteotomy
design and movement)

Cephalometric Data
Magniﬁcation calibrated for both scanned argentic ﬁlm and digital rx
•X-Y cranial base coordinate constructed through sella with the x-
axis at SN-7°
•Symphysis thickness measured between ACP-PCP 4 mm below
the apex of /1
•Vertical chin height: perpendicular distance from MP to lower
incisor tip
•Remodeling above the chin: at B & symphysis thickness increase
•Remodeling in the area of inferior border: ∆ of the notch at
posterior limit of osteotomy cut (PGP to MP)

Recommendation for genioplasty
•For all subject
•Following Precious &
Delaire’s guidelines
✦ Clinical evaluation of the
prominence and vertical
position of the soft tissue
chin relative to the lips and
midface

Problems with Strain on Lip Closure
•Flattening of anterior surface of the chin due to active contraction of
labiomental muscles to achieve lip closure
•Periosteal tension. Absence of muscular balance
•Alveolar bone thinning ➜ root prominence ➜ gingival recession

Cephalometric Data
•A-P chin deficiency
✦ Assessed by /1-APg
•Vertical excess
✦ Assessed by mandibular dental height (male 39,9± 2,7; female 38,9 ± 2,4
mm)
•Most patients had both A-P chin deficiency and excessive mandibular anterior
dental height
✦ While a few had primarily A-P chin deficiency or vertical excess.

Cephalometric Data
•A-P chin deﬁciency
✦ Assessed by /1-APg
✓ 72 % of the pre-surgical and control patients had
prominence > 1 mm
Baseline : /1-APg (°)
Group N Mean S-D Range
Group 1 (< 15yr) 28 3.01 1.49 0.4 to 5.3
Group 2 (15-19) 16 3.67 1.74 -1,2 to 6.5
Group 3 (> 19) 10 2.73 1.90 -0.3 to 5.6
Group 4 (control) 23 3.18 1.56 1.0 to 5.8

Cephalometric Data
•Vertical excess
✦ Assessed by mandibular dental height (male 39,9± 2,7; female 38,9 ±
2,4 mm)
✓ 70 % of pre-surgical and controls patients, this distance was > 43 mm
Baseline : ADH
Group N Mean S-D Range
Group 1 (< 15yr) 28 44.88 2.67 37.1 to 50,7
Group 2 (15-19) 16 45.92 3.27 40.1 to51.1
Group 3 (> 19) 10 48.00 4.76 36.9 to 53.1
Group 4 (control) 23 43.90 2.39 39.5 to 49.6

Statistical Analysis
•Distribution of the sample was evaluated and judged close enough
to normal to use mean, s-d, and range as descriptive statistics
•Design of the study involved comparison between 3 age groups
who underwent genioplasty (gr 1, 2, 3) and comparison of the
youngest group (gr 1) to an age-matched control group (gr 4) with
the same characteristics

•For both comparison
✦ Changes scores between time points were analysed with
multivariate ANCOVA, where gender effect was evaluated as a
covariate
✦ Although gender did not contribute to the differences, we kept
this effect in the model to adjust the conclusion for gender

•One-sample T tests
✦ Evaluate the chance that data for each sample point was different from 0
•Pairwise comparisons with Bonferroni adjustments for multiple comparison
was use to evaluate the change between time points
✦ Unlike the Tukey adjustment, the Bonferroni method does not need
correction because of the unbalanced sample size groups
✦ IBM SPSS Statistics version 21

Method error
•15 cephalograms re-digitized (5 patients X 3 cephs)
✦ 41 variables X 3 time points X 5 patients = 615
✦ Coefficient of fidelity = 0,99968
•Symphysis thickness and PGP
✦ Coefficient of fidelity = 0,92306
• No significant difference between initial and re-digitized tracing
• SAS 9.4 (SAS Institute Inc.)
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Change at Surgery
•Typical change after 
functional genioplasty
• Isn't this a nicer outcome?
• What would be the  
long-term beneﬁt from  
14y 7m to adulthood?

•Typical change after 
functional genioplasty
Change at Surgery
Follow-up 2 y
LPTr 160800
Follow-up 15 y
LPTr 030713

13y4m 14y7m
~ 2 month post genio
~ Follow up 2 years ~ Follow up 15 years
pre genio

Change at Surgery
•The changes were highly signiﬁcant (< .0001)
•No signiﬁcant differences between the 3 groups
•Mean advancement 6,1 ± 2,2 mm; vertical reduction 3,3 ± 2,5 mm
Horizontal Change at Pg
Gr 1 (<15 y)
Gr 2 (15-19 y)
Gr 3 (>19 y)
0,0 1,0 2,0 3,0 4,0 5,0 6,0 7,0 8,0 9,0 10,0
5,25
5,88
6,45
Gr 1 (<15 y) Gr 2 (15-19 y) Gr 3 (>19 y)
Vertical Change at Me
(mm)
0,0
1,0
2,0
3,0
4,0
5,0
6,0
7,0
Gr 1 (<15 y) Gr 2 (15-19 y) Gr 3 (>19 y)
3,833,53
2,93

Symphysis Thickness Changes
•Signiﬁcant increase for the 3 groups
•Slight but signiﬁcant decrease for Controls
•T1-T3
✦ Gr 1 = 3,44 ± 2,51 (p < .001)
✦ Gr 2 = 2,15 ± 1,88 (p < .001)
✦ Gr 3 = 1,04 ± 1, 16 (p = .027)
✦ Gr 4 = -0,44 ± 0,67 (p = .004)
•Pairwise comparison (bonf. adjust.) Gr 1 ≠ Gr 3 (p =.024) (Gr 2 ≠ Gr 1 or Gr3)
1,29
1,11
2,4
T3T2
T3T1
-2,0 -1,0 0,0 1,0 2,0 3,0 4,0 5,0 6,0 7,0
-0,44
-0,44
1,04
1,11
2,15
2,06
3,44
3,24
Gr 1 (<15)
Gr 2 (15-19)
Gr 3 (>19y)
Gr 4 (Controls)

•Youngest group
✦ 39%: ≥2 to <4 mm increase
✦ 28%: ≥4 mm increase
✦ ≥2 to ≥4: Gr 1 ≠ Gr 3 (p=.011)
•Gr 2
•Gr 3
✦ No patients > 4 mm change
•Gr 4 Controls:
✦ 30% = > -1 mm decrease (and 39% = -1 to 0)
better
remodeling
Two-thirds
{

Pg Change in Coordinate Position
•Combination of growth and surface  
remodeling at or near the chin
•T2-T3
✦ Signiﬁcant change from 0
✓ Gr 1 & Gr 4
✦ But change Gr 1 ≠ Gr 4
✦ Non Sig. for Gr 2 & Gr 3

Me Change in Coordinate Position
•Combination of growth and surface remodeling 
at or near the chin
•T2-T3
✦ Vertical growth of Gr 1 similar to Gr 4
✓ Gr 1, Gr 2, Gr 4 (Controls)
✦ Non Sig. change for Gr 3

Vertical dentoalveolar
Change in Coordinate Position
•T2-T3
✓ Gr 1, Gr 2, Gr 3, Gr 4
✦ Change of Gr 1 ≠ Gr 2, Gr 3 & Gr 4
•Vertical change at Me was balanced  
by posterior facial growth
✦ FMA change is non Sig. for any Gr

Pairwise Comparison Between Groups
•Confirms significant difference 
in symphysis thickness change  
Gr 1 (<15y) vs G3 (>19 y)
•Confirms that remodeling  
in Gr 1 (<15y) is different from  
remodeling in Gr 3 (>19 y) 
and Gr 4 (controls)

What could explain bone remodeling?
•Is it:
✦ The amount of genial advancement?
✦ The vertical dentoalveolar growth?
✦ The total face height growth?
✦ The Age at surgery?

★But R2 is low (7%, 10% and 16%)
• Amount of genial advancement (T1-T2). r = 0.264; p = .028
• Vertical dentoalveolar growth (∆ADH). r = 0.316; p = .011
• Age at surgery. r = -0.396; p = 0.002
Correlations
•3 Variables signiﬁcantly correlated to postsurgical change in
symphysis thickness (outcome at T3)

Regression:
Dependent variable: Symphysis thickness
•If the predictor variable change of 1 standard deviation, the dependent variable
increase of the Coefﬁcient Beta (s.-d.)
• Ranking the predictor variable
✦ Genial advancement (∆Pg horiz) St. co. ß = 0,264; p= 0.057
✦ Vertical dentoalveolar growth (∆ ADH) St. co. ß = 0,272; p= 0.049
✦Age at surgery St. co. ß = -0,332; p= 0.032
✦ The younger the age at surgery and the better the dentoalveolar growth, the
more the symphysis will increase in thickness due to bone apposition
Genial
advancement =
Not a determinant

Remodeling Changes of the
Notch
•Remodeling of the symphysis involves
✦ Bone apposition above the repositioned chin
✓ With changes leading up to and beyond B point
✓ Removal of bone adjacent to the notch in the lower border

Remodeling Changes
of the Notch
•T2-T3
✦ Signiﬁcant change for Gr 1 & Gr 2
✓ Reduction of the notch 1,17 & 0,62 mm  
respectively
✦ Non Sig. change for Adult (Gr 3) & Controls

Typical Remodeling Pattern
Young Patients
•Greatest symphysis thickness increase (3,24 ± 2,68 mm (p = .000))
•Greatest remodeling at the notch (1,17 ± 1,29 (p =.000)) & bone apposition at B (1,06 ± 1,33
mm (p = .000))

Correlation:
Dependent variable: PGP_MP at T3
• ∆ ADH_change T3T2 r = 0.311; p = 0.012
• ∆ PGP_change T3T2 r = 0.322; p = 0.009
• Age at surgery r = -0.331; p = 0.008
★ Signiﬁcantly correlated to the outcome of inferior border remodeling at T3
★ But R2 is low (~10%)

Regression:
Dependent variable: PGP_MP at T3
•Predictor variable
✦Dentoalveolar growth change (∆ ADH) St. co. ß = 0,272; p= 0.049
• Change of 1 standard deviation of the dentoalveolar growth will change the dependent variable of 0.272 standard deviation.
✦ The greater the dentoalveolar growth, the more the notch on the inferior
border will be remodelled
✦ Neither the amount of genial advancement (∆Pg) nor the age at surgery were
signiﬁcant predictors of the outcome
✦ The decreased incisors eruption after genioplasty in older adolescent and adults
is the primary reason for better remodeling in young patients

Therefore
•The age at genioplasty, which affects the amount of incisor eruption
afterward, does make a difference in the extent of both bone
apposition and remodeling
•More apposition and remodeling in patients under age 15, less in
late adolescents and still less in adults

Stability of the Surgical Repositioning
•Postsurgical changes are due to
✦ Combination of mandibular growth & surface  
remodeling near the chin
•Gr 1 vs Gr control
✦ Mean AP change after genio of Gr 1 is less than Controls  
(i.e. slightly more stable) but the difference is small and non sig. (p =
0,09)
✦ Vertical change is similar Gr 1 vs Controls

Therefore
•Forward and downward growth at the chin was not signiﬁcantly
affected by genioplasty
•Changes in chin position were maintained in growing patients

Data from this study shows
•Amount of new bone formation after
genioplasty
•Extent of remodeling around the
repositioned chin
✦ Greater in patients still in mid-
adolescence than in late adolescents
and adults
♀ 14y6m
♂ 31y8m
♀ 16y3m

♂HuPi 17y 2m T3 Sept 2005♂HuPi 14y 7m postgenio T2 Feb 2003
Data from this study
•Conﬁrm and extend reports by Martinez et al (JOMS1999)
✦ Better healing in patients younger than age 15

Remodeling
•Our study support other findings
✦Bone remodeling at the inferior border of the proximal segment between the distal
point of the osteotomy cut and the advanced distal segment
✦Gr 1 and Gr 2:
✓ Significant reduction of this notch (1,2 ± 1,3 mm; 0,6 ± 0,9 mm)
✦Gr 3:
✓ Modest non-significant reduction (0,3 ± 1,0 mm)
Polido WD, de Clairefont RL, Bell WH. Bone resorption, stability, and soft-tissue changes following large chin advancements. J Oral Maxillofac Surg 1991; 49:251-6 
Davis WH, Davis CL, Daly BW,Taylor C. Long-term bony and soft tissue stability following advancement genioplasty. J Oral Maxillofac Surg 1988; 46:731-5.
Tulasne JF.The overlapping bone flap genioplasty. J Craniomaxillofac Surg 1987; 15:214-21.
Precious DS, Cardoso AB, Cardoso MC, Doucet JC. Cost comparison of genioplasty: when indicated, wire osteosynthesis is more cost effective than plate and screw fixation. Oral
Maxillofac Surg 2013, posted on web site Nov 23.
Park HS, Ellis E, Fonseca RJ, Reynolds ST, Mayo KH.A retrospective study of advancement genioplasty. Oral Surg Oral Med Oral Path 1989; 67:481-9.
Polido WD, Bell WH. Long-term osseous and soft tissue changes after large chin advancements. J Craniomaxillofac Surg 1993; 21:54-9.

Growth
•Control group has signiﬁcant resorption at B point (0,4 ± 0,6
mm; p = .007)
✦ Symphysis thickness decrease (0,44 ± 0,67 mm; p = .004)
•Consistent with the usual pattern of growth
✦ Chin more prominent by resorption above Pg extending upward toward + above B
point
Marshall SD, Low LE, Holton NE, Franciscus RG et al. Chin development as a result of differential jaw growth.
Am J Orthod Dentofac Orthop 2011; 139:456-64
Our data
B →
Gr 1: 1,06 ± 1,33
Gr 2: 0,85 ± 1,14
Gr 3: 0,69 ± 1,00
Gr Control
← B
Gr C: -0,36 ± 0,58

Remodeling
•All 3 age group had similar bone apposition at B point (0,7 to 1,0 mm)
✦ Like Park et al 1989, Shaughnessy et al 2006, Precious et al 1992 & 2013
•Bony angles above repositioned chin became rounded, rough edge
became smooth.

Remodeling
•Shaughnessy et al suggested that autogenous bone grafts from the
iliac crest placed above the repositioned distal  
segment were responsible for the improved  
contours
•None of our patients received a graft
•All had signiﬁcant bone apposition at B point
•Bone grafting is questionable particularly form a donor site like iliac
crest that requires invasive surgery
Shaughnessy S, Mobarak KA, Hogevold HE, Espeland L. Long-term skeletal and soft-tissue responses after advancement genioplasty.Am J Orthod Dentofac Orthop 2006; 130:8-17.
AJODO 2006; 130:8-17

Skeletal vs Chronological Age
•Would it make a difference?
✦ Recent review of methods to establish peak growth at adolescence
concluded that chronological age is better (Mellion et al, AJODO 2013)
✓ Group younger than 15 years might had some relatively mature girls
✓ Age-15-19 group might had some relatively immature boys
✦ That would have minimized rather than augmented the differences
observed
Mellion ZJ, Behrents RG, Johnston LE. The pattern of facial skeletal growth and its relationship to various common indexes of maturation.
Am J Orthod Dentofacial Orthop 2013;143:845–854.

Remodeling
•Increased remodeling of the facial alveolar bone above osteotomy
site
✦ Bone apposition at B point (0,7 to 1,0 mm)
✓ Permits better bone support for the lower incisors
‣ May help preventing mucogingival problems buccal to lower
incisors or bone dehiscence
‣ This help to explain the thickening of the symphysis thickness
during follow up

Follow-up 2 years
AML030806AML240304
End of ortho
AML030314
Follow-up 10 years
Post Genio
LPTr210998
Follow-up 2 years
LPTr160800
End of ortho
LPTr060697
Follow-up 15 years
LPTr160513
Control
Gr 1 (< 15y)

Growth
•No evidence support a negative effect on mandibular growth from
genioplasty
✦ Whether done early or late adolescence
•FMA decrease during normal growth
✦ Same as in younger genioplasty patients and controls
•Once lower canines are erupted (~ 12-13 y)
✦ No problem to do a genioplasty

•Change, or lack of it, in typical control patient
•Lip incompetency persist, facial convexity persist, bone resorption occurs at B, symphysis thickness decrease

•Change, or lack of it, in typical control patient
•Lip incompetency persist, facial convexity persist, bone resorption occurs at B, symphysis thickness decrease
AML030314
Follow-up 10 years

Stability
•Previous study reported that genioplasty is the most stable orthognathic
surgery procedure
✦ Tulasne, using different surgical procedure, reported greater relapse (40%) in younger patient
✦ Martinez et al reported greater relapse (16%) but not clinically nor statistically sig.
Davis WH, Davis CL, Daly BW,Taylor C. Long-term bony and soft tissue stability following advancement genioplasty. J Oral Maxillofac Surg 1988; 46:731-5.
Shaughnessy S, Mobarak KA, Hogevold HE, Espeland L. Long-term skeletal and soft-tissue responses after advancement genioplasty.Am J Orthod Dentofac Orthop 2006; 130:8-17.
Erbe C, Mulié RM, Ruf S.Advancement genioplasty in Class I patients: predictability and stability of facial profile changes. Int J Oral Maxillofac Surg 2011; 40:1258-62.
Tulasne JF.The overlapping bone flap genioplasty. J Craniomaxillofac Surg 1987; 15:214-21
Martinez JT,Turvey TA, Proffit WR. Osseous remodeling after inferior border osteotomy for chin augmentation: an indication for early surgery. J Oral Maxillofac Surg 1999; 57:1175-80, discussion 1181.

Stability
•Relapse at Pg can be estimated by Pg to N perp-FH
✓ Gr 1: -0,48 mm (7%)
✓ Gr 2: -0,86 mm (14,7%)
✓ Gr 3: -0,24 mm (4,7%)
✦ Relapse T2T3 is not signiﬁcant for any group (p > .235 Anova Gr * Time)
✦ Relapse is similar between group, (p > .176 Anova Time * Gr)

Stability
•Our findings do not support greater relapse at Pg for younger
growing patients
•91% had wire fixation
•Better post-surgical stability with more costly bone screws and
plates may not be a consideration
Precious DS, Cardoso AB, Cardoso MC, Doucet JC. Cost comparison of genioplasty: when indicated, wire osteosynthesis is more cost effective than plate and screw fixation. Oral
Maxillofac Surg 2013, posted on web site Nov 23.

Why I don't like rigid fixation for a
genioplasty
Poor contact between distal
& proximal segment
Screw Embed
Lu.Mo.010710 Lu.Mo.130212
Bone formation over superior
portion of fixation device and
resorption in area of inferior
portion of fixation device
Resorptive zone
Apposition zone
Externalization of
the fixation
Poor remodeling between
distal & proximal segment
540$ Can

Externalization of ﬁxation device
•Resorption of the buccal surface  
of the distal fragment
•Source of discomfort
Precious, D. S, Cardoso A.B., Cardoso M.C.A.C., Doucet J-C. "Cost Comparison of Genioplasty: When Indicated, Wire Osteosynthesis Is
More Cost Eﬀective Than Plate and Screw Fixation." Oral Maxillofac Surg 18, no. 4 (2013): doi:10.1007/s10006-013-0437-y

Courtesy Dr Dany Morais
Why do I prefer osteosynthesis?
Resorptive
zone
De.Le060608
De.Le130410
Resorptive zone (R)
Apposition
zone (A)
Improved contact
between proximal and
distal segment
Precious D., Armstrong J., Morais D., Anatomic placement of fixation device in genioplasty, OOO 1992,; 73-2-8
Precious, D. S, Cardoso A.B., Cardoso M.C.A.C., Doucet J-C. "Cost Comparison of Genioplasty: When Indicated, Wire Osteosynthesis Is More
Cost Effective Than Plate and Screw Fixation." Oral Maxillofac Surg 18, no. 4 (2013): doi:10.1007/s10006-013-0437-y
Complete coverage of fixation wires
by bone and smooth labial cortical
bone of anterior mandible
5$ Can

•On average old adolescent
✦ Significant ∆ Symphysis thickness: 2,06
± 1,24 (p = .000)
✦ Significant bone apposition at B
✓ ∆ B horizontal: 2,13 ± 1,92 mm (p = .
000)
✓ ∆ BPg to MP: 0,85 ± 1,14 mm (p = .
009)
✦ Significant remodeling of the notch on
the inferior border
✓ ∆PGP to MP: 0,62 ± 0,88 mm (p = .
013)
♂GaBo T1 July 08 17y 1m
♂GaBo T2 August 08 17y 2m
♂GaBo T2 August 10 19y 2m

•On average adults shows,
✦ Signiﬁcant increase of symphysis
thickness: 1,11 ± 1,02 mm (p = .011)
✦ Small, but n.s. bone apposition at B
✓ ∆ B horizontal: 1,9 ± 1,42 mm (p =
.004)
✓ ∆ BPg to MP: 0,69 ± 1,00 mm (n.s)
✦ A few if any bone remodeling at the
inferior border
✓ ∆PGP to MP: 0,30 ± 1,00 mm (n.s.)

Beneﬁts of Functional Genoplasty
•Increased symphysis thickness
•Bone apposition at B point
•Remodeling at the inferior border
•Better bone apposition and remodeling is observed in younger
patients than adults

Beneﬁts of Functional Genioplasty
•Improved facial proportions
•Improved smile aesthetics and display of the incisors
•Lip competency in function and repose
•Decrease muscular periosteal tension above the chin and bone
apposition at B point

•Genial advancement and vertical reduction move up the lower lip along
with the chin eliminating the display of the lower teeth when smiling
Initial Follow up 2 y in retention
Proﬃt, William R., and Raymond P. White, Jr. "Combined Surgical-orthodontic Treatment: How Did It Evolve and What Are the Best
Practices Now?" AJODO 147, no. 5 (2015): doi:10.1016/j.ajodo.2015.02.009.

Functional Genioplasty
•When indications for such a genioplasty are recognized
✦ Early surgical correction (< age 15)) produces a better outcome
in terms of bone remodeling
✦ This is related to greater vertical growth of the dentoalveolar
process in younger patients
✦ There is no difference in post-surgical stability in younger and
older patients

Further study
•Soft tissue changes relative to hard tissue changes
•Long term change and stability.
✦ Patients are currently recalled and we have 24 patients at T4 (4 to 10
years post genio) so far.

Stability / Lower Incisors
• Unpaired T Test
✦ FMIA change n.s. for any groups
• Unvariate ANOVA
✦ No sig. diff. between any groups
• Therefore, we cannot
conclude that incisors stability
beneﬁts from genioplasty
0,80$
1,04$
0,72$
)0,61$
)4,50$
)4,00$
)3,50$
)3,00$
)2,50$
)2,00$
)1,50$
)1,00$
)0,50$
0,00$
0,50$
1,00$
1,50$
2,00$
2,50$
3,00$
3,50$
4,00$
4,50$
5,00$
Mean%
∆FMIA%T2,T3%
Group$1$(<$15$y)$
Group$2$(15)19)$
Group$3(>19)$
Group$4$(Control)$
Tendency to proclination in Gr 4

Surgical Tx planning
/1-APg
Md1-APO(mm) 1.5 1.0
ADH_Md1MP(mm)44.6 39.9
N-A-Pg (°) 6.4 4.5
Md1-APO(mm) 4.3 1.0
N-A-Pg(°) 13.3 4.5
/1-APg
Md1-APO(mm) 1.7 1.0
N-A-Pg(°) 4.8 4.5
OutcomeVTOPre surgery

Clinical Soft Tissue Evaluation
Lip incompetency
at repose
Pinching the mentalis
muscle brings the
lips together

Clinical Soft Tissue Evaluation
Mentalis
Vertical excess
}
} } Vertical
excess

• How many cases have you
ﬁnished with such a
proﬁle?
• Isn’t this a better
outcome?
MaLa 13 y Sept.10 MaLa 13 y 4 m January 11

• And the beneﬁt
long-term?
MaLa 13 y Sept.10 MaLa 13 y 4 m January 11 MaLa 15 y 5 m Feb. 13

• Class I occlusion achieved
• Lip strain persist
• Chin projection deﬁcient
• LFH slightly excessive
♂HuPi 12y 4m pre-ortho ♂HuPi 14y 6m postortho T1 Feb 2003
Lip incompetency

• Genioplasty
• 29 days post surgery
• Lip competency achieved
♂HuPi 14y 7m postgenio T2 Feb 2003
29 days post surgery
♂HuPi 14y 6m postortho T1 Feb 2003
Lip incompetency

• Profile benefits
from
genioplasty
• Significant
bone
remodeling at
and near the
chin
♂HuPi 14y 7m postgenio T2 Feb 2003
29 days post surgery
♂HuPi 14y 6m postortho T1 Feb 2003
Lip incompetency
♂HuPi 17y 2m T3 Sept 2005
30 months into retention
Lip competency

KiLe250511 11y8m KiLe160913 14y KiLe091213 14y2m

CaLe280313 Ti
16y 2m T1
CaLe220413 T2
16y 3m T1
CaLe211113 Follow up 7 months
16y 9m Prog 7 months

h
MC Si 07-91 16y 7m MC Si 04-93 18y 5m MC Si 08-93 18y 8m MC Si 04-95 20y 4m

• Young adult
✦ Bone apposition at B
✦ Good bone remodeling at the inferior border
SéRh 04-99 22y 9m 09-99 23y 2m 09-01 25y 1m
01-07 30y 6m
Follow up 7 years post genio

♀KaBo Feb 02 initial
♀31y 7m Feb 02 initial
♀KaBo Feb 04 Progress
♀33y 7m Feb 04 PreGenio
• Class I
• Bimaxillary protrusion
• Lip incompetency

♀KaBo Feb 02 initial
♀31y 7m Feb 02 initial
• 3 months
post genio
• Improved
facial
aesthetics 
& 
Lip
competency 
at repose 
3 months postgenio
1 month postgenio
3 months postgenio

♀33y 7m Feb 04 PreGenio 3 months postgenio
1 month postgenio
3 months postgenio
KaBo June 06 2y post genio
• Follow up 2 y
• Some bone
apposition at
B point
• Inferior
border notch
remain

3 months postgenio
1 month postgenio
3 months postgenio
• Follow up 7 y
• Beneﬁts from
genioplasty
are obvious
• Notch on the
inferior
border remain 
KaBo May 13 7y post genio

• What would happen if you
recommend a genioplasty to
achieve lip competency?
GeAu 29y 4 m May 08 GeAu May10

• Advancement and
vertical reduction
help to achieve
✦ Lip competency
at repose
GeAu 29y 4 m May 08 GeAu May10 GeAu June10

• Bone apposition
occurred
• Overbite improved
• Improved smile
display
• She's happy!
GeAu 29y 4 m May 08GeAu May10 GeAu June10
Initial Follow up 2 y in retention
GeAu Jan13

Thank you
Dr William Profﬁt
my son Pier-Eric Chamberland
www.slideshare.net/sylvainchamberland
www.sylvainchamberland.com
A special thank you to
and my wife Carole for her support

Functional genioplasty in growing patients

Functional genioplasty in growing patients

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