scholarly journals Evaluation of facial soft tissue thickness in asymmetric mandibular deformities after orthognathic surgery

Author(s):  
Luo Huang ◽  
Zhicong Li ◽  
Jing Yan ◽  
Lunqiu Chen ◽  
Zheng-guo Piao

Abstract Objectives The purpose of this study was to compare differences in facial soft tissue thickness in three-dimensional (3D) images before and after orthognathic surgery in patients with skeletal Class III malocclusion and to obtain a better understanding of the relationship between hard and soft tissue changes after surgery. Materials and method The present retrospective study included 31 patients with skeletal Class III malocclusion with mandibular chin deviation greater than 4 mm who had undergone cone-beam computed tomography before and 6 months after surgery. Seven bilateral points were established. Measurements were taken from software-generated multiplanar reconstructions. The predictor variables were timing (pre- and postoperatively) and side (deviated vs. nondedicated). A regression model and correlation analysis were conducted for statistical analysis. Results The difference of bilateral facial soft tissue thickness was statistically significantly different between deviated and nondeviated sides (P < 0.05), with lower values observed on the deviated side. The soft tissue thickness has become nearly symmetric at local regions of the lower thirds of the face after orthognathic surgery. However, most measurements showed a negative correlation between changes in soft tissue thickness and changes in bone tissues. Conclusions Skeletal Class III malocclusion with facial asymmetry is accompanied by differences in soft tissue thickness when comparing Dev and N-Dev sides of the posterior region of the mandible, where soft tissues are thinner on the Dev side. Soft tissue thickness can compensate for or camouflage the underlying asymmetric mandible. In addition, the asymmetric soft tissue thickness on the lower third of the face can be partially improved by orthognathic surgery, but the amount of soft tissue thickness change is not consistent with that of hard tissue positional change.

2018 ◽  
Vol 10 (1) ◽  
pp. 1-8
Author(s):  
Daniele Gibelli ◽  
Matteo Zago ◽  
Annalisa Cappella ◽  
Claudia Dolci ◽  
Chiarella Sforza

Background: The anatomical assessment of the arrangement of facial soft tissues has important applications in different fields from orthodontics to plastic surgery. One of the issues concerns the relationship between facial soft tissue thickness and skeletal class. Literature mainly deals with adult populations, whereas very few studies have been focused on children. Objective: This study aims at investigating the relationship between midline facial soft tissue thickness and skeletal classes in Italian pre-treatment orthodontic child patients. Methods: Lateral cephalometric X-ray films were obtained from 220 healthy Caucasoid children (91 males and 129 females), aged between 6 and 18 years (Class I: 41 males and 70 females; Class II: 18 males and 25 females; Class III: 32 males and 34 females). All the films were digitized and 14 soft tissue thicknesses were measured on the midface; in addition, the skeletal class was assessed according to the corrected ANB angle (ANBc). Differences in facial soft tissue thickness according to sex and skeletal class were assessed through two-way ANOVA test (p<0.01). Results: Statistically significant differences according to sex were found for labrale superius, stomion and labrale inferius, with thicker soft tissues in males than in females (p<0.01). Only measurements at labrale superius and gnathion showed statistically significant differences according to skeletal class, with thicker soft tissues in Class III children and thinner ones in Class II children (p<0.01). Conclusion: The limited number of investigations, as well as the differences in protocols, renders the comparison of results from different studies difficult, suggesting further investigations to enlighten this complex and debated anatomical issue.


2018 ◽  
Vol 8 (2) ◽  
pp. 22-28
Author(s):  
Ravi Kumar Mahto ◽  
Dashrath Kafle ◽  
Pankaj Kumar Singh ◽  
Sonika Khanal ◽  
Siddhartha Khanal

Introduction: Variations in facial soft tissue thickness have been established previously by studies conducted in different population. Hence, it is essential to obtain facial soft tissue thickness measurement data specific to a population and develop individual standards. The objective of this research is to obtain facial soft tissue thickness data of Nepalese adult male and female subjects seeking orthodontic treatment with different sagittal skeletal malocclusion and evaluate variations in facial soft tissue thickness. Materials & Method: Facial soft tissue thicknesses was measured manually on ninety pretreatment lateral cephalogram at eleven points (Glabella, Nasion, Rhinion, Subnasale, Labrale superius, Stomion, Labrale inferius, Labiomentale, Pogonion,Gnathion and Menton). One-way Analysis of variances [one-way ANOVA] followed by Least significant difference (LSD) post hoc test was used to determine difference in facial soft tissue thickness measurements among three sagittal skeletal group for both sexes. In addition, Student’s t-test was used to find difference in facial soft tissue thickness between the male and female subjects in each skeletal Class. Result: Statistically significant differences were found at points Rhinion, Subnasale, Labrale superius, Stomion and Gnathion in males and at Subnasale, Labrale superius, Stomion and Labrale inferius in females while comparing facial soft tissue thickness among three sagittal skeletal classes. Also, it was observed that mean facial soft tissue thickness was greater for males as compared to female subjects with significant differences at Subnasale, Labrale superius, and Labrale inferius in each skeletal Class. Conclusion: Facial soft tissue thickness varies considerably among different population group, sex and sagittal relationship of jaws.


2011 ◽  
Vol 139 (7-8) ◽  
pp. 439-445
Author(s):  
Tatjana Tanic ◽  
Zorica Blazej ◽  
Vladimir Mitic

Introduction. Orthodontic treatment of dento-skeletal anomalies is generally based on the correction of teeth and jaws relationship, while it is expected that soft facial tissue spontaneously adapts to therapeutically achieved relationship and to accompany hard tissue changes. Objective. To establish facial soft tissue thickness conditioning by the presence of dento-skeletal anomalies. Methods. The study was performed at the Dental Clinic of Nis, and involved the analysis of cephalometric rendgenograms in 121 patients, aged 12-18 years, with no previous orthodontical treatment. According to dento-skeletal relationship between teeth and jaws the patients were divided into four groups; class I (control group), class II of division 1, class II of division 2 and class III. The standard analysis of dento-skeletal profile was done according to Steiner and soft tissue profile according to Burstone was done in all. Results. The patients of class II/1 had a significantly thinner upper lip (t=2.650; p<0.05) and thinner upper lip sulcus (t=1.999; p<0.05). The patients of class II/2 had a significantly thicker upper lip (t=2.912; p<0.01), while those of class III had a significantly thinner lower lip (t=3.900; p<0.001). Conclusion. The thickness of facial soft tissue considerably influences facial profile appearance in persons with a dento-skeletal anomaly. Not only do soft tissues adapt to the existing jaws relationship, but can also camouflage present anomalies.


2010 ◽  
Vol 63 (7-8) ◽  
pp. 470-474
Author(s):  
Maja Stosic ◽  
Mirjana Janosevic ◽  
Mirjana Buric ◽  
Gordana Filipovic

The aim of the research was to determine the characteristics of soft tissue in persons with class III malocclusion, through the analysis of profile X-rays. The research was carried out on fifty profile X-rays of people with class III malocclusion (eighteen males and thirty two females, from the age of fifteen to twenty five). Linear and angular parameters were analyzed by Burston?s and Steiner?s method. The increased soft tissue thickness in subspinal region in both genders had a partial compensatory effect. The reduced upper and lower lip thickness in females created more harmonious profile in relation to males, in whom lip thickness shows great individual variations. The increased soft tissue thickness in supramental region in males emphasized the abnormality in relation to females.


2021 ◽  
pp. 1-14
Author(s):  
Wenjie Xu ◽  
Hao Tan ◽  
Xuehuan Meng ◽  
Ye Ming ◽  
Tao Wang ◽  
...  

OBJECTIVE: To investigate three-dimensional soft tissue changes of lips and related jaw changes in patients with skeletal class III malocclusion and facial asymmetry using cone-beam computerized tomography (CBCT). METHOD: This study included 46 CBCT scans of patients with aforementioned character before (T1) and 6–12 months after orthognathic surgery (T2). Subjects were divided into 2 groups according to two types of orthognathic surgery namely, the one-jaw surgery group who underwent bilateral sagittal splint ramus osteotomy (BSSRO) and the two-jaw surgery group who underwent Le Fort I osteotomy and BSSRO. Mimics 19.0 software are used for model reconstruction, landmark location and three-dimensional cephalometric analysis. Descriptive statistics and correlation analyses are used to investigate jaw hard tissue and lip soft tissue changes. RESULTS: In one-jaw group, the mandible shows changes in contour and position (p <  0.05), and the surgery causes changes of lip structure on the deviated side. While in two-jaw group, jaws only show changes in spatial position, and surgery changes contour of bilateral lips and nasolabial angle (p <  0.05). At the same time, lip symmetry increases significantly in both groups postoperatively. CONCLUSIONS: Orthognathic surgery can improve lip aesthetics in patients with skeletal class III malocclusion and facial asymmetry. However, changes induced by two surgical approaches are different. Surgeons should have a clear acquaintance with this difference to deal with different situations.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0245760
Author(s):  
Ryan M. Campbell ◽  
Gabriel Vinas ◽  
Maciej Henneberg

In modern humans, facial soft tissue thicknesses have been shown to covary with craniometric dimensions. However, to date it has not been confirmed whether these relationships are shared with non-human apes. In this study, we analyze these relationships in chimpanzees (Pan troglodytes) with the aim of producing regression models for approximating facial soft tissue thicknesses in Plio-Pleistocene hominids. Using CT scans of 19 subjects, 637 soft tissue, and 349 craniometric measurements, statistically significant multiple regression models were established for 26 points on the face and head. Examination of regression model validity resulted in minimal differences between observed and predicted soft tissue thickness values. Assessment of interspecies compatibility using a bonobo (Pan paniscus) and modern human subject resulted in minimal differences for the bonobo but large differences for the modern human. These results clearly show that (1) soft tissue thicknesses covary with craniometric dimensions in P. troglodytes, (2) confirms that such covariation is uniformly present in both extant Homo and Pan species, and (3) suggests that chimp-derived regression models have interspecies compatibility with hominids who have similar craniometric dimensions to P. troglodytes. As the craniometric dimensions of early hominids, such as South African australopithecines, are more similar to P. troglodytes than those of H. sapiens, chimpanzee-derived regression models may be used for approximating their craniofacial anatomy. It is hoped that the results of the present study and the reference dataset for facial soft tissue thicknesses of chimpanzees it provides will encourage further research into this topic.


2021 ◽  
Author(s):  
Ryan Miles Campbell ◽  
Gabriel Vinas ◽  
Maciej Henneberg

In modern humans, facial soft tissue thicknesses have been shown to covary with craniometric dimensions. However, to date it has not been confirmed whether these relationships are shared with non-human apes. In this study, we analyze these relationships in chimpanzees ( Pan troglodytes ) with the aim of producing regression models for approximating facial soft tissue thicknesses in Plio-Pleistocene hominid individuals. Using CT scans of 19 subjects, 637 soft tissue, and 349 craniometric measurements, statistically significant multiple regression models were established for 26 points on the face and head. Examination of regression model validity resulted in minimal differences between observed and predicted soft tissue thickness values. Assessment of interspecies compatibility using a bonobo ( Pan paniscus ) and modern human  (Homo sapiens ) subject resulted in minimal differences for the bonobo but large differences for the modern human. These results clearly show that (1) soft tissue thicknesses covary with craniometric dimensions in  P. troglodytes , (2) confirms that such covariation is uniformly present in both extant  Homo  and  Pan  species, and (3) suggests that chimp-derived regression models have interspecies compatibility with hominids who have similar craniometric dimensions to  P. troglodytes . As the craniometric dimensions of early hominids, such as South African australopithecines, are more similar to  P. troglodytes  than those of  H. sapiens , chimpanzee-derived regression models may be used for approximating their craniofacial anatomy. It is hoped that the results of the present study and the reference dataset for facial soft tissue thicknesses of chimpanzees it provides will encourage further research into this topic.


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