مقاله دکتر همت پور (nasolabial soft tissue changes after bimaxillary surgery…)

Frontal-view nasolabial soft tissue alterations after bimaxillary orthognathic surgery in Class III patients

Abstract

Introduction The aim of this before–after clinical trial was to evaluate nasolabial soft tissue changes in the frontal
plane after bimaxillary surgery. Methods A total of 20 skeletal Class III Iranian patients needing bimaxillary Le Fort I osteotomy plus mandibular setback surgery were enrolled in this trial. Patients underwent 4.02 ± ۱.۰۲ mm of maxillary advancement (Le Fort I osteotomy, 4.33 ± ۱.۲۱ mm in men, 3.81 ± ۰.۸۶ mm in women) and 7.13 ± ۱.۷۴ mm of mandibular setback (intraoral vertical ramus osteotomy, 7.71 ± ۲.۳۳ mm in men, and 6.74 ± ۱.۱۶ mmin women). Data were acquired via 2D frontal photographs. We compared pretreatment baseline (T1), preoperative postorthodontic treatment (T2), and postoperative (T3) anthropometric measurements using repeated- measures ANOVA and Bonferroni tests (a = 0.05). Result The 20 patients (12 men, 8 women) were aged 21.85 ± ۱.۷۵ years. Between T1 and T2, nasal width, cutaneous upper labial heights increased overall; cutaneous lower labial height decreased (P\0.05). Between T2 and T3, nasal width, widths of the philtrum and mouth, cutaneous upper-lip height, vermilion height of the lower lip,
lateral upper-lip height increased; the upper-lip vermilion height and cutaneous lower lip height decreased (P\0.05). The changes ranged between 0.5 and 5 mm. Conclusion The applied orthognathic surgery procedures might widen the alar base and mouth width. It might increase the lateral upper-lip height, vermilion height of the lower lip, and cutaneous and overall upper-lip heights while reducing upper-lip vermilion height and shortening the overall lower-lip height. Keywords Orthognathic surgery  Maxillary advancement  Le Fort I osteotomy  Mandibular setback  Intraoral vertical ramus osteotomy
Zusammenfassung Einleitung Ziel dieser klinischen Vorher-nachher-Studie war es, die nasolabialen Weichteilvera¨nderungen in der frontalen Ebene nach bimaxilla¨rem Eingriff zu evaluieren. Methoden Insgesamt 20 iranische Klasse-III-Patienten, bei denen eine kombinierte Le-Fort-I-Osteotomie und Unterkieferru ¨ckverlagerungindiziert war, wurden in die Studie aufgenommen. Erreicht wurden eine Oberkiefervorverlagerung von 4,02 ± ۱,۰۲ mm (Le-Fort-I-Osteotomie, 4,33 ± ۱,۲۱ mm bei den ma¨nnlichen, 3,81 ± ۰,۸۶ mm bei den weiblichen Patienten) und eine Unterkieferru¨ckverlagerung von 7,13 ± ۱,۷۴ mm (vertikale Osteotomie des Ramus, 7,71 ± ۲,۳۳ mm bei den ma¨nnlichen und 6,74 ± ۱,۱۶ mm bei den weiblichen   Patienten). U¨ ber 2-D frontale Fotografien wurden Daten erhoben. Verglichen wurde mittels ANOVA (Analysis of Variance) fu¨r wiederholte Messungen und dem Bonferroni-Test (a = 0,05) Daten jeweils zu den Zeitpunkten Baseline (T1), pra¨operative postkieferorthopa¨dische Behandlung (T2) und postoperativ (T3). Ergebnis Die Patienten (12 Ma¨nner, 8 Frauen) waren zwischen 21,85 ± ۱,۷۵ Jahre alt. Zwischen T1 und T2 erho¨hten sich die Nasenbreite und die kutanen Oberlippenho¨hen insgesamt, die kutane Unterlippenho¨he verringerte sich (p\0,05).Zwischen T2 und T3 erho¨hten sich dieNasenbreite, die Breite von PhiltrumundMund spalte, die kutaneHo¨he der Oberlippe, die Ho¨he des Unterlippenrots und die seitliche
Oberlippenho¨he, dagegen verringerten sich die Ho¨he des Oberlippenrots und die kutane Unterlippenho¨he (p\0,05).
Das Ausmaß der Vera¨nderungen lag zwischen 0,5 und 5 mm. Schlussfolgerung Mittels der durchgefu¨hrten Eingriffe der
orthognathen Chirurgie verbreiterten sich die Nasenbasis und die Mundspalte. Zudem vergro¨ßerten sich die laterale Oberlippenho¨he, die Ho¨he des Unterlippenrots sowie die kutane und die Gesamtho¨he der Oberlippe, wa¨hrend die
Ho¨he des Oberlippenrots und die Gesamtho¨he der Unterlippe abnahmen. Schlu¨sselwo¨rter Kieferorthopa¨dische Chirurgie  Oberkiefervorverlagerung  Le-Fort-I-Osteotomie  Unterkieferru¨ckverlagerung  vertikale Osteotomie des
Ramus

Introduction

Facial appearance can affect patients’ emotional well-being and their quality of life [16, 23, 30]. The soft tissue profile strongly affects a patient’s perception after orthognathic surgery [7]. Although occlusal and functional improvement is essential in orthognathic surgery, most patients are more concerned about alterations in facial proportions, nose and lips, and the facial contour [7]. Therefore, the patient’s appearance is a key aim of orthodontic treatment and orthognathic surgery [23], and treatment planning depends on skeletal relationships and functional occlusion as well as
soft tissue adaptations [23, 34]. The treatment of moderate to severe Class III malocclusions frequently requires a combination of orthodontic and orthognathic surgical procedures. Bimaxillary surgery is being done more frequently because of its more favorable facial aesthetic outcome [23]. In most cases, the aims of such procedures are to correct the dental malocclusion,
improve facial appearance, and harmonize the facial profile [10, 14, 17, 23, 34]. Therefore, it is important that the clinician is able to predict soft tissue changes resulting from alterations in the hard tissue. Many studies have attempted to evaluate the relationship between hard tissue surgery and the effects it leaves on overlying soft tissues [10, 14, 17, 23, 27, 34]. By changing skeletal tissues, orthognathic surgery can modify facial soft tissue contours. It can therefore enhance facial attractiveness. However, the influence of skeletal surgery on soft tissue profiles is not easy to predict [7, 19]. Although the literature is replete with studies that employed lateral cephalometry for soft tissue analysis, that method cannot provide information on what occurs in the frontal aspect, which is especially important when assessing changes in the nose and lips [35]. Patients view themselves in the mirror and can find it difficult to relate to information presented solely as profile analysis [35]. Moreover, soft tissue landmarks in cephalometry are not as readily reproducible as those of skeletal landmarks, a factor that can reduce the reliability of cephalometry in soft tissue assessment [7, 9, 10]. Other methods of soft tissue analysis include three-dimensional (3D) reconstruction and evaluation (e.g., computerized tomography [CT], cone-beam CT [CBCT], and 3D surface scanning technologies such as laser scanning), Moire topography, photocephalometry, stereophotogrammetry, photography, and anthropometry [3, 24, 25, 36]. Anthropometry is an objective technique for quantifying facial morphology to evaluate facial harmony and predict soft tissue modification in response to skeletal changes [12, 18, 35]. Unlike isolated mandibular setback surgery that results in more predictable soft tissue responses [10, 20, 23], bimaxillary surgery might cause more complicated soft tissue alteration patterns [10, 14, 23]. Therefore, an assessment of bimaxillary orthognathic surgical outcome on facial and lateral anthropometric measurements is worthwhile, especially as patients’ ethnic backgrounds may play a role in soft tissue changes that follow skeletal alterations. Most previous studies evaluated the outcomes of either mandibular setback or maxillary advancement, not both. The paucity of studies on bimaxillary surgery is an obvious justification for addressing this issue. Moreover, the results after bimaxillary surgery are controversial, and there is a shortage of evidence concerning soft tissue changes in the frontal view. Finally, there has been no study on postoperative changes in Iranians published to date. We therefore conducted this before-andafter clinical trial to evaluate the results of preoperative orthodontic treatment as well as bimaxillary orthognathic surgery on profile and frontal soft tissue measurements in subjects presenting a severe skeletal Class III malocclusion.

Materials and methods

This prospective before-and-after clinical trial was performed in 20 skeletal Class III Iranian patients (Caucasians) who underwent bimaxillary Le Fort I osteotomy plus mandibular setback surgery by one surgeon from 2011 to 2013. The protocol ethics were approved by the Research Committee of the Islamic Azad University, in accordance with the Helsinki declaration. Patients signed written consent forms.

Sample

Included were all patients who needed orthognathic surgery (based on the malocclusions, SNA and ANB angles, and diagnosis of severe Class III cases according to McNamara and Wits analyses) and underwent a combined single-piece Le Fort I osteotomy and advancement with rigid fixation as well as intraoral vertical ramus osteotomy. Patients with a cleft lip or palates or other congenital craniofacial anomalies, vertical problems, facial asymmetries, or lip cants were excluded. All patients had undergone orthodontic treatment prior to surgery to enable a proper reverse overjet for the surgical phase. There were 8 women and 12 men in our study cohort. Their average age was 21.85 ± ۱.۷۶ years (range 19–۲۵ years; 22.13 ± ۱.۶۴ years in men and 21.67 ± ۱.۸۷ years in women). All patients presented a bilateral full-cusp Class III relationship. Fourteen of the patients underwent non-extraction orthodontic treatment, five had their maxillary first premolars extracted, and one underwent extraction of the maxillary first premolars and mandibular second premolars. The average extent of reverse overjet was 7.0 ± ۲.۱۲ mm at the end of the orthodontic phase. All extraction and non-extraction orthodontic treatments included maxillary expansion. The average maxillary expansion in the second premolar width and molar width areas was 3.4 ± ۱.۲ and 2.5 ± ۱.۳ mm, respectively. The decision to or not to extract was made by evaluating the incisor inclination and dentoskeletal discrepancy. All patients had undergone 4.02 ± ۱.۰۲ mm of maxillary advancement without any bone grafts (4.33 ± ۱.۲۱ mm in men and 3.81 ± ۰.۸۶ mm in women). The plate shapes were straight-3 holes in piriform rims (anterior), and L-type-4 holes in the buttress area (posterior),
in a combination with nasal alar cinch and V–Y. The patients underwent 7.13 ± ۱.۷۴ mm of mandibular setback (7.71 ± ۲.۳۳ mm in men and 6.74 ± ۱.۱۶ mm in women). The mandibular setback technique we applied was intraoral vertical ramus osteotomy, as none of the patients wanted to undergo subcondylar osteotomy because of its potential complications. In the first phase (pretreatment), 16 patients were lip competent and four were lip incompetent, the latter presenting 3, 2, 1, and 1 mm lip incompetence. They had anterior open bites of 2, 2, 1, and 1 mm. By the second phase (between orthodontic treatment and surgery), all patients had become lip incompetent. Since all patients were free of any vertical anomalies (as an inclusion criterion), in the third phase (after surgery), all patients were lip competent and presented a normal overbite (2–۳ mm). Patients’ SNA and SNB angles at the start of treatment were 73 ± ۲ and 85 ± ۲, respectively. Their clinical characteristics included a concave profile, paranasal deficiency, negative lip step, and chin prominence. No additional surgical procedure was performed.

Imaging

As routine clinical procedures, standardized lateral cephalograms and panoramic radiographs, in addition to standardized frontal and profile photographs (EOS 5D Mark II, Canon) were taken immediately before treatment, immediately after the completion of the orthodontic preoperative phase (entailing the leveling, alignment and decompensating phases, which took 1–۲ years), and again 7.0 ± ۱.۰۲ months after surgery. A professional photographer expert in orthodontic photography took all the truesize patient photographs of the patients in natural head position (NHP) with the soft tissue at rest. The camera was vertically aligned with the patients’ Frankfort planes. The new image taken in each session was later overlapped on that patient’s previous image(s). If the borders and components in the upper one-third of the face’s images from the two sessions did not match perfectly, another image was taken in the same session. Magnification of the standardized cephalograms was verified as true-size by measuring the image on the cephalostat ruler.

Measurement of the extent of surgical displacement

A single experienced surgeon carried out every surgical intervention. Cephalometric measurements taken on pretreatment and postoperative digitized cephalograms were used to measure the extent of jaw displacement after surgery. The digitized tracings were superimposed in reference to the sella-nasion line and on natural cranial structures. The horizontal distances between the baseline A and B points with the postoperative A and B points were measured as was the extent of the jaws’ advancement and setback (Fig. 1).

Anthropometric photographic measurements

Profile digital photographs were verified as being true sized, by superimposing them on the true-size lateral cephalographs. In frontal photographs, this was confirmed by comparing the clinical intercanthal width with that measured on the image. All measurements were taken by a single examiner. Digitized lateral cephalograms superimposed on the profile

photograph were evaluated once at baseline before surgery (T1) and once 7.0 ± ۱.۰۲ months after surgery (T3). On them, the N–SN distance was measured at 0.1 mm accuracy; also the angle measurements ‘columella Inclination, nasolabial, and labiomental’ were measured at 0.5
accuracy. The frontal photographs were evaluated before therapy (T1), after completion of the preoperative phase (T2), and after surgery (T3). On the frontal photographs, anthropometric nasolabial measurements between the landmarks ‘alare (Al), crista philtri (Cph), cheilion (Ch), sub nasion (Sn), labiale superius (Ls), stomion superius (Stms), stomion inferius (Stmi), labial inferius (Li), sublabial (Sl), and subalare (Sbal)’ (Fig. 2; Table 1) were recorded as described by Farkas [11].

Tab. 1 Linear anthropometric measurements Tab. 1 Lineare anthropometrische Messungen Definition Measurement
Nasal width Al–Al Width of the philtrum Cph–Cph Width of the mouth Ch–Ch Cutaneous upper lip height Sn–Ls Vermilion height of upper lip Ls–Stms Overall upper lip height Sn–Stms Vermilion height of lower lip Stmi–Li Cutaneous lower lip height Li–Sl Overall lower labial height Stmi–Sl Lateral upper lip height (right) Sbal–Ls (right) Lateral upper lip height (left) Sbal–Ls (left) Al alare, Cph crista philtri, Ch cheilion, Sn sub nasion, Ls labiale superius, Stms stomion superius, Stmi stomion inferius, Li labial inferius, Sl sublabial, Sbal subalare

Statistical analysis and method error

The reproducibility of our measurements was determined by selecting 10 random photographs and having the same examiner repeat the measurements one month after the initial measuring procedure. We observed no significant errors when the repeated measurements were subjected to paired t test. The sample size was based on the study of Altug-Atac et al. [1]. Due to the great uniformity of our inter-individual and intra-individual data, the present cohort size (n = 20 9 3) yielded post hoc test power above 99 % for most parameters. A one-way repeated-measures analysis of variance (ANOVA) and Bonferroni post hoc tests were used to assess soft tissue anthropometric changes on the frontal view. The paired t test was used for comparison of measurements on the profile photographs superimposed on lateral cephalographs. The level of significance was set at 0.05.

Result

The measurements at each time point and differences between them are demonstrated in Tables 2 and 3, respectively. According to the repeated-measures ANOVA and paired t test, most of the changes measured between the intervals were highly significant except for the changes

Tab. 2 Measurements (in cm) before orthodontic treatment (T1), after orthodontic treatment
(T2), and after orthognathic surgery and postoperative orthodontic treatment (T3)

Tab. 2 Messwerte (cm) vor (T1) und nach (T2) kieferorthopa¨discher Behandlung sowie nach orthognather chirurgischer Intervention und postoperativer kieferorthopa¨discher Behandlung (T3)

Tab. 3 Discrepancies between measurements (in cm) recorded at T2 and T1, between T3 and T2 and between T3 and T1. The P values are calculated using the Bonferroni post hoc test, following the ANOVA, results of which are presented in Table 2

Tab. 3 Diskrepanzen (in cm) zwischen den bei T2 und T1 bei T3 und T2 sowie zwischen den bei T3 und T1 bestimmten Messwerten. Die p-Werte wurden mit dem Post-hoc-Test nach Bonferroni im Anschluss an die ANOVA (Ergebnisse in Tab. 2) berechnet

Fig. 3 The average measurements (in cm) and their 95 % confidence intervals at each time point. *ANOVA’s P\0.05; ***P\0.001 Abb. 3 Durchschnittliche Messwerte (cm) und entsprechende 95 %- Konfidenzintervalle zu den verschiedenen Zeitpunkten. *ANOVA-p-Wert\0,05; ***p\0,001

in Stmi–Li and N–Sn (Fig. 3; Tables 2, 3). The Bonferroni test indicated that soft tissue anthropometric changes after orthodontic treatment were negligible, apart from the Al– Al measurement. However, the postoperative changes became obvious when compared to the initial baseline measurements or those taken after orthodontic treatment (Table 3). In the preoperative orthodontic phase, the width of the nose, height of the cutaneous upper lip, and height of the upper lip were significantly increased, while the height of the cutaneous lower lip was significantly decreased. After surgery, the nose width, philtrum width, width of the mouth, height of the cutaneous upper lip, vermilion height of the lower lip, height of the upper lip, and height of the lateral upper lip were significantly increased, but the vermilion height of the upper lip, and heights of the lower lip and cutaneous lower lip were significantly decreased

Discussion

This study performed on Caucasians from the Middle East region shows that alar width increased after orthognathic surgery. Maxillary forward and upward movement by the aid of Le Fort I osteotomy generally widens the alar base [24, 29, 32]. This sort of disfigurement might be more serious for Asians, who usually present a wider alar base and lower columellar height than Caucasians [6, 13, 24]. After surgery, all our measurements changed significantly compared to those taken before or after orthodontic treatment. Alar width increase might have resulted from damage to the alar base

supporting muscle attachments. Such alar widening has been reported [7, 24, 28, 36] even after making alar-cinch suture [28]. Maxillary posterior impaction without maxillary advancement may minimize alar widening [7]. In the present study, we observed significant upper lip changes including lengthening of cutaneous upper labial height and overall upper labial height, and a shorter vermilion upper-lip height, as mentioned in previous studies [5, 21, 22, 27, 35]. Some authors reported increases in total upper lip height, but failed to show changes in the vertical relation between the upper lip’s vermilion and cutaneous fraction [27]. Baik and Kim [2] observed no significant changes in mouth or philtrum width. The upper lip is attached to the anterior nasal spine. This may explain why that region follows the skeletal shift [34]. In this study, significant lower-lip changes included a shorter cutaneous lower labial height and longer vermilion height of the lower lip, in line with previous studies [21, 22]. This may be explained by the fact that the lower lip’s relaxation after the tension caused by the lower teeth and alveolar bone has been eliminated via the mandibular setback, which eventually eliminates lip incompetence and enables a better lip seal. After surgical treatment, lateral upper lip height (right and left) increased significantly. This
is similar to published results [4]. Some maintain that the increase in mouth width might be the artifact of a decrease in bigonial width [7]. In the current study, we observed elongated lip length, consistent with some other studies [10, 33], but unlike another that reported a negligible change in mouth width [7].

Limitations and advantages

This study was limited by some factors. Soft tissue can swell immediately after surgery, which is why it is advisable to wait for a minimum of 6 months to a year after surgery before assessing any changes [8, 24, 29]. Most of the working groups addressing the response of nasolabial soft-tissue to skeletal alterations in the nose after orthognathic surgery utilized lateral cephalometric radiographs, which cannot capture changes in the frontal view [15, 16, 24, 31]. On the other hand, our method is also limited by factors such as errors caused by head posture [24]. Soft tissue changes can be more accurately assessed in 3D. However, we did not have 3D surface scanning technology available, and taking CTs or CBCTs merely for research purposes is unethical (unjustified X-ray exposure) [16, 26]. It should be noted that the frontal and lateral landmarks examined in this 2D research might still be clinically important, as they reflect what is usually crucial for the patient: to look better in the mirror [35]. Besides, 3D methodology is also problematic because of the overwhelming amount of data and difficulty in superimposing before- and after-surgery images because of the complexity
of the structures and head position, factors that would raise
the likelihood of error and reduce the reproducibility [24, 25]. Many 3D studies have reported changes in landmarks in three dimensions while neglecting the effects of such changes in the frontal perspective. That is less relevant to the major goal of orthognathic surgery which is to make patients more attractive in the frontal aspect. As another limitation, the extraction/non-extraction treatment protocols could have impaired our cohort’s uniformity and reduced the reliability. However, the homogeneity was confirmed by high statistical power and very significant results. Moreover, including both treatment protocols improves the generalizability of our findings. Finally, it might be argued that since there are numerous factors involved, 100 % accuracy in predicting the outcome of surgery is not possible. Nonetheless, even imperfect prognoses are still useful, as such approximations are the basis of all the empirical sciences.

Conclusion

Within the limitations of this study, we have shown that bimaxillary orthognathic surgery in class III cases can widen the alar base and mouth width. It might also increase slightly the vermilion height of the lower lip while shortening the upper lip’s vermilion height, and increasing the cutaneous and overall upper labial heights. In addition, it might increase the lateral upper lip height and reduce the overall lower labial height. These findings imply that in the frontal view, almost every nasolabial parts undergo changes measuring about 5 mm or less. These side effects of bimaxillary surgical correction of Class III patients might be tolerable by patients with fuller and narrower lips and thinner noses; however, they might be less favorable for those with already broad noses or lips and for those with thinner lips (shorter lip heights). Clinicians should notify patients regarding the possibility of such changes before deciding for the treatment plan. Future studies are warranted to assess whether these frontal-view changes can affect the perception of beauty in the eye of laypeople and orthodontic patients, and if so, positively or negatively. Author contributions and acknowledgments S. Hemmatpour conceived, designed, mentored the study, and performed orthodontic treatments. F. Kadkhodaei-Oliadarani did the cephalometric and photographic analyses, wrote the thesis, and prepared Fig. 1. A. Hasani mentored the thesis. V. Rakhshan designed and performed the statistical analyses, hand-drew Fig. 2, and drafted/revised the paper. Authors wish to express their sincere gratitude to Prof. Mesgarzadeh
for performing the surgeries.

Compliance with ethical guidelines
Conflict of interest S. Hemmatpour, F. Kadkhodaei-Oliadarani, A. Hasani, and V. Rakhshan declare that they have no competing interests.

References

۱. Altug-Atac AT, Bolatoglu H, Memikoglu UT (2008) Facial soft
tissue profile following bimaxillary orthognathic surgery. Angle
Orthod 78(1):50–۵۷

۲. Baik HS, Kim SY (2010) Facial soft-tissue changes in skeletal
Class III orthognathic surgery patients analyzed with 3-dimensional
laser scanning. Am J Orthod Dentofacial Orthop 138(2):
۱۶۷–۱۷۸

۳. Blockhaus M, Kochel J, Hartmann J et al (2014) Three-dimensional
investigation of facial surface asymmetries in skeletal
malocclusion patients before and after orthodontic treatment
combined with orthognathic surgery. J Orofac Orthop 75(2):
۸۵–۹۵

۴. Brooks BW, Buschang PH, Bates JD et al (2001) Predicting
upper lip response to 4-piece maxillary LeFort I osteotomy. Am J
Orthod Dentofacial Orthop 120(2):124–۱۳۳

۵. Chew MT (2005) Soft and hard tissue changes after bimaxillary
surgery in Chinese Class III patients. Angle Orthod 75(6):
۹۵۹–۹۶۳

۶. Choe KS, Yalamanchili HR, Litner JA et al (2006) The Korean
American woman’s nose: an in-depth nasal photogrammatic
analysis. Archives of facial plastic surgery 8(5):319–۳۲۳

۷. Choi JW, Lee JY, Oh T-S et al (2014) Frontal soft tissue analysis
using a 3 dimensional camera following two-jaw rotational
orthognathic surgery in skeletal class III patients. J Craniomaxillofac
Surg 42(3):220–۲۲۶

۸. Chung C, Lee Y, Park KH et al (2008) Nasal changes after surgical
correction of skeletal Class III malocclusion in Koreans.
Angle Orthod 78(3):427–۴۳۲

۹. Donatsky O, Bjørn-Jørgensen J, Hermund NU et al (2009)
Accuracy of combined maxillary and mandibular repositioning
and of soft tissue prediction in relation to maxillary antero-

superior repositioning combined with mandibular set back A
computerized cephalometric evaluation of the immediate postsurgical
outcome using the TIOPS planning system. J Craniomaxillofac
Surg 37(5):279–۲۸۴

۱۰. Enacar A, Taner T, Toroglu S (1999) Analysis of soft tissue
profile changes associated with mandibular setback and doublejaw
surgeries. Int J Adult Orthodon Orthognath Surg 14(1):27–۳۵

۱۱. Farkas LG (1994) Anthropometry of the head and face. Raven Pr,
New York, NY

۱۲. Farkas LG, Hreczko TA, Kolar JC et al (1985) Vertical and
horizontal proportions of the face in young adult North American
Caucasians: revision of neoclassical canons. Plast Reconstr Surg
۷۵(۳):۳۲۸–۳۳۸

۱۳. Farkas LG, Katic MJ, Forrest CR et al (2005) International
anthropometric study of facial morphology in various ethnic
groups/races. J Craniofac Surg 16(4):615–۶۴۶

۱۴. Jensen AC, Sinclair PM, Wolford LM (1992) Soft tissue changes
associated with double jaw surgery. Am J Orthod Dentofacial
Orthop 101(3):266–۲۷۵

۱۵. Kang EH, Park SB, Kim JR (2000) Nose changes after maxillary
advancement surgery in skeletal Class III malocclusion. Korean J
Orthod 30(5):657–۶۶۸

۱۶. Khosravanifard B, Rakhshan V, Raeesi E (2013) Factors influencing
attractiveness of soft tissue profile. Oral Surg Oral Med
Oral Pathol Oral Radiol 115(1):29–۳۷

۱۷. Ko EW-C, Huang CS, Chen YR (2009) Characteristics and corrective
outcome of face asymmetry by orthognathic surgery.
J Oral Maxillofac Surg 67(10):2201–۲۲۰۹

۱۸. Kolar JC, Salter EM (1997) Craniofacial anthropometry: practical
measurement of the head and face for clinical, surgical, and
research use. Charles C. Thomas Publisher, Springfield

۱۹. Legan HL, Burstone CJ (1980) Soft tissue cephalometric analysis
for orthognathic surgery. J Oral Surg 38(10):744–۷۵۱

۲۰. Lim Y-K, Chu E-H, Lee D-Y et al (2010) Three-dimensional
evaluation of soft tissue change gradients after mandibular setback
surgery in skeletal Class III malocclusion. Angle Orthod
۸۰(۵):۸۹۶–۹۰۳

۲۱. Marsan G, Cura N, Emekli U (2009) Soft and hard tissue changes
after bimaxillary surgery in Turkish female Class III patients.
J Craniomaxillofac Surg 37(1):8–۱۷

۲۲. Mars¸an G, Oztas¸ E, Kuvat SV et al (2009) Changes in soft tissue
profile after mandibular setback surgery in Class III subjects. Int J
Oral Maxillofac Surg 38(3):236–۲۴۰

۲۳. Oh K-M, Seo S-K, Park J-E et al (2013) Post-operative soft tissue
changes in patients with mandibular prognathism after bimaxillary
surgery. J Craniomaxillofac Surg 41(3):204–۲۱۱

۲۴. Park S-B, Yoon J-K, Kim Y-I et al (2012) The evaluation of the
nasal morphologic changes after bimaxillary surgery in skeletal
class III maloccusion by using the superimposition of cone-beam
computed tomography (CBCT) volumes. J Craniomaxillofac
Surg 40(4):e87–e92

۲۵. Park SH, Yu HS, Kim KD et al (2006) A proposal for a new
analysis of craniofacial morphology by 3-dimensional computed
tomography. Am J Orthod Dentofacial Orthop 129(5):600.e623–
۶۳۴

۲۶. Rakhshan V (2015) Meta-analysis of observational studies on the
most commonly missing permanent dentition (excluding the third
molars) in non-syndromic dental patients or randomly-selected
subjects, and the factors affecting the observed rates. J Clin
Pediatr Dent 39(3):199–۲۰۷

۲۷. Raschke GF, Rieger UM, Peisker A et al (2015) Morphologic
outcome of bimaxillary surgery—an anthropometric appraisal.
Med Oral Patol Oral Cir Bucal 20(1):e103–e110

۲۸. Rauso R, Tartaro G, Tozzi U et al (2011) Nasolabial changes
after maxillary advancement. J Craniofac Surg 22(3):809–۸۱۲

۲۹. Rosen HM (1988) Lip-nasal aesthetics following Le Fort I
osteotomy. Plast Reconstr Surg 81(2):171–۱۸۲

۳۰. Rustemeyer J, Gregersen J (2012) Quality of life in orthognathic
surgery patients: post-surgical improvements in aesthetics and
self-confidence. J Craniomaxillofac Surg 40(5):400–۴۰۴

۳۱. Ryckman MS, Harrison S, Oliver D et al (2010) Soft-tissue
changes after maxillomandibular advancement surgery assessed
with cone-beam computed tomography. Am J Orthod Dentofacial
Orthop 137(4 Suppl):S86–S93

۳۲. Sarver DM, Weissman SM (1991) Long-term soft tissue response
to LeFort I maxillary superior repositioning. Angle Orthod
۶۱(۴):۲۶۷–۲۷۶

۳۳. Sforza C, Peretta R, Grandi G et al (2007) Soft tissue facial
volumes and shape in skeletal Class III patients before and after
orthognathic surgery treatment. J Plast Reconstr Aesthet Surg
۶۰(۲):۱۳۰–۱۳۸

۳۴. Soncul M, Bamber MA (2004) Evaluation of facial soft tissue
changes with optical surface scan after surgical correction of
Class III deformities. J Oral Maxillofac Surg 62(11):1331–۱۳۴۰

۳۵. Vasudavan S, Jayaratne YS, Padwa BL (2012) Nasolabial soft
tissue changes after Le Fort I advancement. J Oral Maxillofac
Surg Off J Am Assoc Oral Maxillofac Surg 70(4):e270–e277

۳۶. Yamada T, Mishima K, Moritani N et al (2010) Nasolabial
morphologic changes after a Le Fort I osteotomy: a three-dimensional
anthropometric study. J Craniofac Surg 21(4):1089–
۱۰۹۵