Effectiveness of orthognathic surgery and the suitability with Vietnamese harmonious faces in class III malocclusion patients

JOURNAL OF MEDICAL RESEARCH

EFFECTIVENESS OF ORTHOGNATHIC SURGERY AND
THE SUITABILITY WITH VIETNAMESE HARMONIOUS
FACES IN CLASS III MALOCCLUSION PATIENTS
Nguyen Hoang Minh¹, Pham Hoang Tuan2, Hoang Thi Doi3,
Nguyen Thi Thu Phương1, Le Van Son1
¹ School of Odontostomatology, Hanoi Medical University
²Hanoi National Hospital of Odontostomatology
3
Hanoi Medical College
Class III malocclusion affects negatively on health, quality of life and psychology. Orthodontic and
orthognathic surgery is necessary for adult patients with skeletal class III malocclusion to achieve good
function and aesthetic. The subjects were 35 patients at Hanoi National Hospital of Odontostomatology,
Viet Duc University Hospital, and Hong Ngoc Hospital from April 2017 to September 2018. This was a
quasi-experimental study with self- comparison, 1 month, 6 months and 12 months follow up. Orthognathic surgery pushed maxilla forward and set back the mandible, corrected occlusion to skeletal class I
intermaxilla reduced mental prognathism, corrected cross bite, dental decompensation. The relationship
among upper and lower lips with nose and chin were aesthetically improved. Twenty patients, which
were followed up after 12 months, had stable post-operation results. In comparision with harmonious
facial index of Kinh ethnic in Vietnam, 80% patients achieved skeletal harmony, 85% patients achieved
dental harmony and 80% achieved soft tissue harmony, 100% patients had quality of life improved. The
more harmonious index patients acquired, the higher quality of life they achieved. In order to improve
surgical effectiveness, harmonious facial index is essential in planning and pre-surgical simulation.

Keywords: class III malocclusion, orthognathic surgery, harmonious faces

I. INTRODUCTION
Malocclusion is the incorrect dental
relation between teeth of two arches.
The rate of malocclusion is high, over
50% worldwide. In America and Asian

Corresponding author: Nguyen Hoang Minh,
School of Odontostomatology, Hanoi Medical
University
Email:
Received: 27/11/2018
Accepted: 15/03/2019

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countries, this rate can be as high as 70%
[1]. Class III malocclusion comprises a
high percentages in the population, up to
35% [2; 3]. Class III malocclusion is the
etiology of occlusal trauma, functional
decrease, and an increased risk of dental
diseases, facial aesthetic and psychological
problems [4]. Treatment for skeletal class III
malocclusion is quite necessary to improve
quality of life [5]. Most of adult patients
with skeletal malocclusion, especially
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JOURNAL OF MEDICAL RESEARCH
class III malocclusion, need a combination
of orthodontic and surgerical treatment
to achieve good outcomes in function
and aesthetic [6]. However, treatment for
skeletal malocclusion is always a challenge
for orthodontists and surgeons. Maxillary

Lefort I osteotomy and bilateral sagittal split
osteotomy ramus are commonly applied
worldwide, providing good outcome in
aesthetic and function in three dimensions,
as well as post operative stability [7; 8].
Domestic longitudinal studies on
orthognathic surgery for patients with
skeletal class III malocclusion is very
limited. The Vietnamese harmonious facial
index is an important factor in assessing
the effectiveness of surgery; hence, the
application of this index in orthognathic
surgery must be calculated. Thus, we
conducted this study with two objectives:
1. To evaluate the effectiveness and
stability of orthognathic surgery in class III
malocclusion patients.
2. To evaluate the suitability with the
Vietnamese harmonious facial index and
satisfaction in skeletal class III malocclusion
orthognathic patients.

II. Method
1. Subjects
Skeletal class III malocclusion patients
were treated with preoperative orthodontic
and orthognathic surgery in Hanoi (Hanoi
National Hospital of Odontostomatology,
Viet Duc University Hospital and Hong Ngoc
Hospital) from April 2017 to September

2018.

44

2. Study method
Quasi-experimental study with self comparison before operation (T0) and after
operation at point in time 1 month (T1), 6
months (T6) and 12 months (T12) follow up;
sample size: N=34 (p = 0.722 in sample size
formula). At the moment, 35 patients have
been followed up for 1 month, 32 patients
have been followed up for 6 months and
20 patients have been followed up for 12
months. Other patients are still followed up.
Before operation, all patients were
examined, took cephalometric Xrays. All
patients were operated with maxillary Lefort
I osteotomy and bilateral sagittal split ramus
osteotomy.
Following
and
evaluating
the
effectiveness
and
stability
of
orthognathic surgery in class III
malocclusion patients
Result assessment after 1 month (T1),

6 months (T6) and 12 months (T12):
clinical examination, cephalometric index
measurement, (skeletal, dental and soft
tissue index).
Evaluating the effectiveness of surgery is
evaluation the changes in facial index before
and after surgery by comparing skeletal,
dental and soft tissue index in preoperation
(T0) and 1 month postoperation (T1).
Evaluating the stability of surgery is
evaluation the changes in facial index
through time after surgery by comparing
skeletal, dental and soft tissue index
in 1 month postoperation (T1) and 6
month postoperation (T6) and 12 month
postoperation (T12).

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Assessment of the suitability with
Vietnamese harmonious facial index in
skeletal class III malocclusion patients
Assess the suitability with Vietnamese
harmonious facial index is assess the
suitability between postoperation facial
index and Vietnamese harmonious facial
index by comparing patients’ cephalometric
indexs after 12 month postoperation with

Vietnamese Kinh Ethnic harmonious facial
index in National Research in School of
Odonto & Stomatology – Hanoi Medical
University.
Assessment of patient satisfaction
after orthognathic surgery correcting
class III malocclusion. Orthognathic
Quality of Life Questionnaire (OQLQ) was
used to evaluate patients’ quality of life and
satisfaction [9]. Average index: ≤ 2: good
quality of life; 2-3: moderate quality of life; ≥
3: poor quality of life.
3. Data analysis
Continuous variables were skeletal,
dental and soft tissue index (SNA, SNB,
ANB angle, A-V, B-V, Pg-V, Wits, over jet,
over bite, U1-SN, Is-V, L1-MP, Ii-V, Li-E, LsE, Cm - Sn – Ls angle, Li - B' - Pg' angle, Ns
- Sn - Pg’ angle) measured in Cephalometric
X – rays which were analysed with SPSS

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16.0 software. If the variables achieved
normal distribution, pair T - test was used.
If the variables cannot achieved normal
distribution, non-parametric test (Wilcoxon
signed rank test) was used.
4. Ethical Considerations
This study belongs to National research
of School of Odonto & Stomatology –

Hanoi Medical University, which had been
approved this study according to Decision
No. 202/HĐĐĐĐHYHN, signed on October
20th 2016.

III. Results
1. Clinical and X-ray characteristics
of class III malocclusion orthognathic
patients
1.1. Clinical characteristics
There were 14 male patients (40%); 21
female patients (60%) in the study with 100
% concave profile. There were twenty one
long facial cases (60%) and 14 mesofacial
cases (40%). No short facial case were
observed.
The average overjet was -4 ± 2.16 mm
and the average overbite was 1.49 ± 0.66
mm.
1.2. X-ray characteristics

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Table 1. Skeletal – dental – soft tissue index on cephalometric by gender
Index

X

± XD

P
(Male – Female)

Male (N = 14)

Female (N = 21)

SNA (degree)

82.59 ± 4.54

79.78 ± 2.83

> 0.05

SNB (degree)

87.69 ± 4.43

83.17 ± 2.87

< 0.01

ANB (degree)

-5.09 ± 3.22

-3.39 ± 1.76

> 0.05

Wits (mm)

-11.90 ± 4.58

-9.83 ± 2.68

> 0.05

U1 - SN (degree)

114.05 ± 9.55

108.13 ± 8.07

> 0.05

L1 - MP (degree)

85.05 ± 11.13

88.13 ± 6.73

> 0.05

Li - E (mm)

4.38 ± 1.27

3.12 ± 0.75

< 0.01

Ls - E (mm)

-2.81 ± 2.19

-3.17 ± 1.31

> 0.05

Cm - Sn - Ls (degree)

73.37 ± 12.30

87.66 ± 13.18

< 0.01

Li - B’ - Pg’ (degree)

147.10 ± 10.29

146.10 ± 11.61

> 0.05

Ns - Sn - Pg’ (degree)

186.43 ± 2.90

184.78 ± 3.56

> 0.05

Comment: Small SNA, large SNB , negative ANB, negative Wits
Maxillary retrognathism,
mandibular prognathism. Small Ls – E
retrognathic upper lip, large Li – E
prognathic
lower lip. Acute nasolabial angle (Cm – Sn – Ls). Obtuse labiomental angle (Li – B’ – Pg’).
Large facial angle (Ns – Sn – Pg’) featured for concave profile. The differences of SNB, Li-E,
Cm-Sn-Ls were statistically significant between males and females.
2. Effectiveness and stability after orthognathic surgery in class III malocclusion
patients
2.1. Skeletal, dental and soft tissue index in 1 month postoperation

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Table 2. Skeletal, dental and soft tissue index 1 month posoperation (T1) in
comparision with preoperation (T0)
Index

T0 (N = 35)

T1 (N = 35)

P
(T0 – T1)

X

SD

X

SD

SNA (degree)

80.90

3.82

84.19

3.37

< 0.001

A - V (mm)

60.50

5.34

64.10

5.17

< 0.001

SNB (degree)

84.97

4.17

81.56

3.66

< 0.001

B - V (mm)

65.41

7.79

60.75

7.75

< 0.001

Pg - V (mm)

66.27

9.32

61.47

9.20

< 0.001

ANB (degree)

-4.07

2.55

2.61

1.51

< 0.001

Wits (mm)

-10.66

3.65

0.04

2.71

< 0.001

Overjet (mm)

-4.00

2.16

2.43

0.66

< 0.001

Overbite (mm)

1.49

0.66

1.66

0.54

> 0.05

U1 - SN (degree)

110.50

9.05

105.50

9.64

< 0.001

Is - V (mm)

67.20

7.34

69.87

6.93

< 0.001

L1 - MP (degree)

86.90

8.74

97.03

4.66

< 0.001

Ii - V (mm)

71.43

8.02

66.96

6.95

< 0.001

Li - E (mm)

3.62

1.16

1.85

0.88

< 0.001

Ls - E (mm)

-3.03

1.69

0.13

0.79

< 0.001

Cm - Sn - Ls (degree)

81.94

14.51

92.56

4.29

< 0.001

Li - B’ - Pg’ (degree)

146.50

10.96

134.19

5.23

< 0.001

Ns - Sn - Pg’ (degree)

185.44

3.37

164.95

2.62

< 0.001

Comment: Forward movement of the maxilla (SNA, A-V increased), backward movement
of the mandible, prognathic chin reduced (SNB, B-V, Pg-V reduced). Class I intermaxillary
relationship was achieved, cross bite was corrected. Forward movement of upper incisors
(Is-V increased), backward movement of lower incisors (Ii-V decreased). Increased angle
between lower incisors and mandibular plane (L1-MP), decreased angle between upper
incisors and cranial plane (U1-SN). Forward movement of upper lip (Ls-E increased),
backward movement of lower lip (Li-E decreased), facial angle decreased (Ns-Sn-Pg’).
Nasolabial angle was larger (Cm-Sn-Ls increased) and labiomental angle was smaller (Li – B’
– Pg’ decreased) in comparision with pre-surgery index. Above changings were statistically
significant (p < 0.05). Overbite changing is not statistically significant (p > 0.05).

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2.2. Skeletal, dental and soft tissue index in 6 month postoperation
Table 3. Skeletal, dental and soft tissue index in 6 month postoperation (T6) in
comparision with 1 month postoperation (T1)
T1 (N = 32)

T6 (N = 32)

X

SD

X

SD

P
(T1 - T6)

SNA (degree)

82.99

3.25

82.83

2.64

> 0.05

A - V (mm)

63.67

5.19

62.94

4.66

> 0.05

SNB (degree)

80.42

3.53

81.42

3.15

< 0.01

B - V (mm)

60.37

7.94

62.60

7.20

< 0.001

Pg - V (mm)

61.13

9.47

63.17

8.50

< 0.01

ANB (degree)

2.56

1.54

1.41

1.19

< 0.01

Overjet (mm)

2.44

0.67

2.00

0.36

< 0.01

Overbite (mm)

1.62

0.55

1.56

0.50

> 0.05

U1 - SN (degree)

105.10

9.79

106.54

8.57

> 0.05

Is - V (mm)

69.33

7.01

69.01

6.38

> 0.05

L1 - MP (degree)

96.85

4.81

95.89

3.13

> 0.05

Ii - V (mm)

66.43

7.03

66.76

6.37

> 0.05

Li - E (mm)

1.84

0.90

1.34

1.61

< 0.05

Ls - E (mm)

0.13

0.81

-0.12

1.54

> 0.05

Cm - Sn - Ls (degree)

92.30

4.26

96.36

4.60

< 0.001

Li - B’ - Pg’ (degree)

133.89

5.33

129.22

4.51

< 0.01

Ns - Sn - Pg’ (degree)

165.17

2.63

166.59

2.62

< 0.001

Index

Comment: Changing in maxillary index (SNA, A - V) was not statistically significant (p
> 0.05). Forward movement of mandible and chin (SNB, B-V, Pg-V increased) (p < 0.05).
Reduction of ANB angle was statistically significant, class I intermaxillary relationship. Overjet
was statistically significantly decreased (p < 0.05), changing in overbite and dental index
(U1 - SN, Is - V, L1 - MP, Ii - V) were not statistically significant (p > 0.05). Upper and lower
lips were set back E-line. Facial angle (Ns - Sn - Pg’) was increased. Larger nasolabial angle
(Cm - Sn - Ls increased), smaller labiomental angle (Li - B' - Pg' decreased) in comparision
with pre-surgery. Those changings were statistically significant (p < 0.05).

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2.3. Skeletal, dental and soft tissue index in 12 month postoperation
Table 4. Skeletal, dental and soft tissue index in 12month postoperation (T12) in
comparision with 6 month postoperation (T6)
T6 (N = 20)

T12 (N = 20)

X

SD

X

SD

P
(T6 - T12)

SNA (degree)

82,83

2,99

82,71

3,36

> 0,05

A - V (mm)

63,81

4,75

63,65

4,89

> 0,05

SNB (degree)

81,44

3,55

81,66

3,82

> 0,05

B - V (mm)

63,33

7,67

63,48

6,53

> 0,05

Pg - V (mm)

63,79

9,10

63,94

8,66

> 0,05

ANB (degree)

1,39

1,18

1,05

1,02

> 0,05

Overjet (mm)

2,05

0,39

2,10

0,31

> 0,05

Overbite (mm)

1,55

0,51

1,60

0,50

> 0,05

U1 - SN (degree)

107,29

9,62

107,44

8,67

> 0,05

Is - V (mm)

69,78

6,81

69,91

6,74

> 0,05

L1 - MP (degree)

95,11

3,43

94,82

3,73

> 0,05

Ii - V (mm)

67,59

6,78

67,23

6,52

> 0,05

Li - E (mm)

1,46

1,80

1,47

2,23

> 0,05

Ls - E (mm)

-0,03

1,75

-0,18

1,81

> 0,05

Cm - Sn - Ls (degree)

94,04

3,52

94,22

4,02

> 0,05

Li - B’ - Pg’ (degree)

132,47

4,31

133,79

7,87

> 0,05

Ns - Sn - Pg’ (degree)

166,72

2,88

167,43

3,55

> 0,05

Index

Comment: Skeletal, dental and soft tissue index in 12 month postoperation was similar to
6 month postoperation index (p > 0.05).
3. The suitability with Vietnamese harmonious facial index and satisfaction in skeletal
class III malocclusion orthognathic patients
3.1. The suitable rate with Vietnamese harmonious facial index

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Figure 1. Suitable rate with Vietnamese harmonious facial index
Comment: Among 20 patients got 12 month postoperative following up, there were 16
cases having harmonious skeletal index (80%), 17 cases having harmonious dental index
(85%) and 16 cases having harmonious soft tissue index (80%). Four cases that did not
achieve the harmonious skeletal, also fail to achieve the harmonious soft tissue index.
3.2. Quality of life changing after surgery

Figure 2. Quality of life changing after surgery
Comment: There was no good quality of life case before surgery. Quality of life was
improved after surgery, there were 17 cases having good quality of life (85%), 3 cases having
moderate quality of life (15%) and there was no case having poor quality of life.
3.3. The suitability between quality of life (QoL) and harmonious face after surgery

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Figure 3. Quality of life and harmonious face
Comment: 100% cases had good quality of life in group harmonious face achieved. Among
4 cases that could not achieve the harmonious face, there were 3 patients having moderate
quality of life and 1 patient having good quality of life. The relation between harmonious face
and quality of life was statistically significant (p < 0.01).

IV. Discussion

1. Clinical and X-ray characteristics in
skeletal class III orthognathic patients


In our study, proportion of females
(60%) was higher than males (40%) due to
the fact that females are more concerned
about aesthetic than males. Index measured
on cephalometrics suggested retrognathism
maxilla, prognathism mandible, dental
compensation (lingual inclination of lower
incisors, labial inclination of upper incisors),
retrognathism upper lip and prognathism
lower lip, acute nasolabial angle, obtuse
labiomental angle, large facial angle.
These results were appropriate with studies
conducted by Aydemir [7], Le Tuan Hung
[10], I-Ming Tsai [11]. Remarkablely negative
ANB and Wits, which suggested large
deviation in anterior-posterior dimension
between maxilla and mandible. These
are characteristics of patients who need
orthognathic surgery.
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2. Effectiveness and
orthognathic surgery
malocclusion

stability after

in class III

1 month postoperation, our study
observed forward movement of the maxilla,
backward movement of the mandible and
intermaxillary relationship was changed
from class III (preoperation) to class I.
Overjet was increased to positive average
value, cross bite was corrected. The angle
between lower incisors and mandibular plane
was increased, the angle between maxillary
incisors and basal plane was decreased,
dental decompensation was achieved
(palatal inclination of upper incisors and
labial inclination of lower incisors), dental
esthetic was improved. Soft tissue was also
changed: forward movement of upper lip,
backward movement of lower lip, decreasing
facial angle, increasing nasolabial angle
as well as decreasing labiomental angle
in comparion with preoperation. These
changes significantly improved facial
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aesthetic, the relationship between upper
lip and nose, lower lip and chin. Our result
was appropriate with studies conducted by
Ghassemi, Le Tan Hung, I-Ming Tsai [8; 10;

11].
At 6 month postoperation, the maxilla was
stable. The mandible was unstable, which
moved forward, reducing overjet. However,
the intermaxillary relationship was still class
I, and positive overjet value remained.
Ghassemi, Le Tan Hung and I-Ming Tsai also
observed unstable mandible after surgery
[8; 10; 11]. This unstable condition was
due to traction of muscle underneath the
mandible, excessive backward movement
of the condyle in fossa, changing in
direction and force of the masseter muscle
and pterygoid muscle, which caused a force
pulling the gonial upward and forward [12].
About soft tisse, higher esthetic relationship
among nose, lips and chin was achieved
(less acute nasolabial angle and less
obtuse labiomental angle), which may be
due to completely disappearance of swollen
situation in comparision with 1-month after
surgery. 20 patients who had been followed
up 12 months had stable skeletal, dental
and soft tissue index. Other patients will be
followed up till 12-month after surgery.
3. The suitability with Vietnamese
harmonious facial index and satisfaction
in skeletal class III malocclusion
orthognathic patients
Among the 20 patients who completed

12-month follow-up, there were 16 cases
having harmonious skeletal index (80%),
17 cases having harmonious dental index
(85%) and 16 cases having har monious
52

soft tissue index (80%). Patients who
had harmonious skeletal index also had
harmonious soft tisse index. Thus, skeletal
index is important, which need to achieved
in planning to help creating harmonious
soft tissue index because it is difficult
to predict accurately soft tissue index
while planning. Dental decompensation,
less acute nasolabial angle, less obtuse
labiomental angle, decreasing facial angle
helps improving facial esthetic significantly.
After surgery, the quality of life had been
raised, and patients were satisfied with their
facial changing, which was similar to studies
of Wee [13]. The more harmonious index
achieved, the better quality of life those
patients acquired. Therefore, harmonious
facial index should be applied in planning
and preoperative simulation to increase
surgical effectiveness and patient’s quality
of life.

V. Conclusion
Maxillary Lefort I osteotomy and bilateral

sagittal split ramus osteotomy were efficient
in correcting skeletal class III malocclusion.
After surgery, the maxilla moved forward,
the mandible moved backward, class I
intermaxillary relationship was achieved,
as well as backward movement of chin,
correction of cross bite and dental
decompensation (palatal inclination of
upper inciors and labial inclination of lower
incisors), thus esthetic was significantly
improved. Forward movement of upper lip,
backward movement of lower lip, decrease
of facial angle, increase of nasolabial angle
as well as decrease of labiomental angle,
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harmonious relationship among nose,
lips and chin were successfully achieved
after surgery. 6-month postoperation, the
mandible was unstable and moved forward.
12-month postoperation, outcomes of 20
patients being followed up were stable.

After surgery, the quality of life had
been raised, and patients were satisfied with
their facial changing. The more harmonious
index achieved, the better quality of
life those patients acquired. Therefore,

harmonious facial index should be applied
in planning and preoperative simulation to
increase surgical effectiveness.

Acknowledgment
We would like to express our sincere
gratitude to volunteers for their participation
in our study, as well as Hanoi National
Hospital of Odontostomatology, Viet Duc
Hospital, Hong Ngoc Hospital, School of
Odonto & Stomatology – Hanoi Medical
University, Assoc.Prof. PhD. Truong Manh
Dung – head of National Research project,
Assoc.Prof. PhD. Vo Truong Nhu Ngoc.

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JMR 118 E4 (2) - 2019