This document summarizes a clinical study that evaluated changes to perioral soft tissues after orthognathic surgery using 3D CT scans. 10 patients who underwent jaw surgery had pre-and post-operative 3D CT scans 12 months after surgery. Measurements of the nasolabial angle, mentolabial angle, and lip width were compared. The results showed that maxillary advancement increased the nasolabial angle by 1.81 degrees per 1mm of movement, while setback decreased it by 2.73 degrees per 1mm. Mandibular advancement decreased the mentolabial angle on average while setback also decreased it. There was no significant change in lip width for most procedures. The study concluded

1. An Evaluation of Perioral Soft Tissue
Changes after Orthognathic Surgery Using
3D CT Scan- A clinical study.
PRESENTED BY
DR. RAHUL TIWARI
REG. NO. - 14085029
FINAL YEAR MDS
DEPT. OF ORAL & MAXILLOFACIAL SURGERY
SIBAR INSTITUTE OF DENTAL SCIENCES
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2. CONTENTS
 INTRODUCTION
 AIMS & OBJECTIVES
 MATERIAL & METHODS
 RESULTS
 DISCUSSION
 CONCLUSION
 REFERENCES
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3. INTRODUCTION
 Facial appearance especially perioral soft tissues is an important factor in
interrelationships between humans, and it affects social and psychological
development.
 Orthognathic surgery has the objective of correcting skeletal discrepancies, as well as
altering the facial balance, to achieve results in patient who have severe disharmony of
jaws.
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4. AIM & OBJECTIVES
 To Evaluate Perioral Soft Tissue Changes after Orthognathic Surgery using the 3D CT
Scan.
 1. Assessment of changes associated with Nasolabial angle.
2. Assessment of changes associated with Mentolabial angle.
3. Assessment of changes associated with Lip width.
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5. MATERIALS AND METHODS
 10 cases presenting to department of OMFS in SIDS
 Patient requiring Orthognathic surgeries will be enrolled requiring 1 jaw or 2
jaw surgeries
 Pre and post operative 3D computerized tomography scan was taken after 12
months with same references points to evaluate the changes associated with
bony movements due to surgery.
 Pre and post-operative facial measurements are taken to evaluate the
soft tissues of face both on computerized tomography & patients.
 The data will be tabulated for mean changes and statistical analysis will
be done.
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6. INCLUSION & EXCLUSION CRITERIA
 Maxillary prognathism and retrognathism
 Mandibular prognathism and retrognathism
 Facial asymmetry
 Systematically ill patients
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7. PARAMETERS
 Lip width- Distance between cheilion of the one side and the other side.
 Nasolabial angle- Angle constructed among columella lobular junction, Sn, and UL.
 Mentolabial angle- Angle constructed among LL, B, and Pog.
 Reference: Jung YJ, Kim MJ, Baek SH: Hard and Soft tissue changes after correction of mandibular prognathism and facial asymmetry by mandibular setback
surgery: three dimensional analysis using computerized tomography. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 107:763, 2009
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8. REFERENCE POINTS-PERIORAL
MEASUREMENTS
S.No
.
Parameter
1 Right Chelion- Rt.Ch
2 Left Chelion- Lt.Ch
3 Lower Lip-ll
4 Upper Lip-ul
5 Soft Tissue Pogonion- Pog .
6
Soft Tissue B Point- B
7
SUBNASALE- Sn
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9. PRE & POST 3DCT IMAGES
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10. PRE & POST 3DCT IMAGES
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11. RESULTS & OBSERVATIONS
S.No.
LE
FORT
LE
FORT
AMO AMO BSSO BSSO SAO
GENIO
Pre op
NLA
(°)
Post
op
NLA
(°)
Pre op
MLA
(°)
Post
op
MLA
(°)
Pre op
LW
(mm.)
Post
op LW
(mm.)
Adv
Set
back
Set
back
Adv
Set
back
Adv
Set
back
Adv
1 - 2mm - 2mm - - - 2mm 119.5° 109.6° 131.5° 106.9° 43.0 40.8
2 4mm - - - 4mm - - - 108.3° 113.9° 155.2° 139.9° 45.0 44.6
3 - - - 5mm - - - - 122.2° 123.1° 113.3° 132.6° 45.2 44.6
4 - 3mm - - - 2mm - - 101.0° 96.7° 133.3° 119.1° 50.4 48.2
5 - 3mm - - - 2mm - - 103.5° 99.4° 152.0° 131.8° 44.3 41.9
6 5mm - - - 6mm - 3mm - 112.3° 123.0° 138.9° 130.8° 36.9 39.9
7 - - - - 4mm - - - 108.1° 108.6° 156.6° 133.1° 42.3 46.4
8 - - 2mm - - - 2mm - 106.5° 100.7° 128.9° 113.5° 46.5 44.7
9 - - - 8mm - - - - 117.9° 118.9° 100.1° 131.3° 46.0 49.3
10 - 3mm - 4mm - - - - 129.3° 117.8° 106.9° 117.0° 42.9 47.5
Total 2 4 3 4 3 2 2 1
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12. RESULTS – NASOLABIAL ANGLE
 In total two patients have underwent maxillary advancement of 4 mm and 5mm in
which the nasolabial angle has increased by 5.6° and 10.7° respectively. So the mean
advancement in the maxilla was 4.5mm and the mean difference was 8.15°.
 Hence 1mm forward movement of maxilla forward there is increase in the
nasolabial angle by 1.81°
 A total of five patients have underwent maxillary setback of 2mm to 3mm in which the
nasolabial angle has decreased by 4.1 to 11.5° respectively. So the mean setback in the
maxilla was 2.6mm and the mean difference was 7.12°.
 Hence 1mm movement of maxilla setback there is decrease in the nasolabial angle
by 2.73°
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13. RESULTS – MENTOLABIAL ANGLE & LIP
WIDTH
 In six patients three patients have underwent mandibular advancement of 2mm
to 8mm. In three patients mentolabial angle was decreased by 7.6° and in other
three patients mentolabial angle increase by 3.6°
 Four patient have underwent mandibular setback of 2mm to 9mm in which
mentolabial angle decreased by 3.27°with 1mm mandibular backward
movement
 There was a significant relationship of lip width change only in the
maxillary setback and mandibular advancement surgery when operated
together.
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14. DISCUSSION
 Our study showed a significant correlation between the amount of maxillary advancement and
nasolabial angle with increase in nasolabial angle by 1.81° after 1mm advancement of maxilla.
 Patrick J Louis found decrease in nasolabial angle by 5° after maxillary advancement of 8 ±2.5 mm.
 Takahiro Shoji also found increase in the nasolabial angle after maxillary advancement by Le-Fort I
osteotomy which is similar to our study.
 The conventional thought of changes in Nasolabial angle after surgery is changing because of
underlying factors which should be considered before prediction.
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Reference: Shoji T, Toshitaka M, Masayuki T, Kazuki A, Tsuchida Y. The stability of an alar cinch suture after Le Fort I and mandibular
osteotomies in Japanese patients with Class III malocclusions. Br J Oral Maxillofac Surg. 2012:50;361–364

15. LIMITATIONS
 Our study sample size was limited to 10 patients in single center.
 The study was not confined to single procedure
 It didn’t considered morphological factors and ageing changes.
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16. CONCLUSION
 1. The amount of maxillary advancement and setback plays a role in the postsurgical
increase and decrease in nasolabial angle respectively.
 2. The amount of mandibular advancement and setback plays a role in the post-surgical
increase and decrease in mentolabial angle respectively.
 3. There is no significant relationship found in the difference on lip width according to the
movement of jaws for surgery.
 4. Following maxillomandibular advancements and setbacks facial soft tissues appear to
respond more as they adapt with increase in time period.
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17. REFERENCES
 Jung YJ, Kim MJ, Baek SH: Hard and Soft tissue changes after correction of
mandibular prognathism and facial asymmetry by mandibular setback surgery: three
dimensional analysis using computerized tomography. Oral Surg Oral Med Oral
Pathol Oral Radiol Endod 107:763, 2009
 Lim YK, Chu EH, Lee DY, et al: three- dimensional evaluation of soft tissues changes
gradients after mandibular setback surgery in skeletal class III malocclusion. Angle
orthod 80:896,2010
 Mc Cance AM, Moss JP, Fright WR, et al: a three dimensional analysis of soft and
hard tissue changes following bi maxillary orthognathic surgery in skeletal class III
patients. Br. J Oral Maxillofac Surg 30:305,1992
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18. REFERENCES
 Honrado CP, Lee S, Bloomquist DS, et al: quantitative assessment of nasal changes after maxilla
mandibular surgery using a 3-dimensional digital imaging system. Arch Facial Plast Surg
8:26,2006
 Altman JI, Oeltjen JC: nasal deformities associated with orthognathic surgery: analysis,
prevention, and correction. J Craniofac Surg 18:734, 2007
 Betts NJ, Vig KW, Vig P, et al: changes in the nasal and labial soft tissues after surgical
repositioning of the maxilla, Int J Adult Orthodon Orthognath surg 8:7, 1993.
 Park SB, Yoon JK, Kim YT, et al: the evaluation of the nasal morphologic changes after
bimaxillary surgery in skeletal class III malocclusion by using superimposition of cone-beam
tomography (CBCT) volumes. J Cranio maxilla fac surg in press, available online 2 july, 2011.
Doi:10.1016/J.jcms.2011.05.008.
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