Copyright © 2019 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
subjective amelioration in nasal breathing. Furthermore, the patients were divided into 2 groups according to preoperative NOSE percentage up to 50% (1st group) and more than 50%
(2nd group). It is aimed that the severity of nasal discomfort effect the postoperative levels of EPO. However, there was no statistical difference between first and second group in terms of pre- and postoperative change in EPO levels (1st group: preop-11.705.07, postop-11.086.31,P¼0.701 vs 2nd group: preop-11.144.85, postop-11.765.78,P¼0.702) which inferred that there was no correlation between the severity of subjective perception of nasal obstruction and EPO levels (Fig. 1).
N/L ratio was found to be increased in inflammatory diseases in many studies.12,13Although NSD is not an inflammatory condition, pre- and post-operative N/L ratio were also analyzed (2.020.96 vs 1.910.92, P¼0.54) and there was no statistically significant difference.
The main limitations of our study are the relatively small sample size and lack of objective assessment of nasal patency with rhinomanometry.
CONCLUSION
This is the first study in the literature which evaluated the relation- ship between NSD and EPO levels. There was no statistical difference found between the pre- and the postoperative 3rd month EPO and Hgb levels. However, there was no statistical difference found in EPO levels even in patients with severe nasal discomfort.
Study limitations could be paucity in the number of patients and lack of objective assessment of nasal patency.
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1. Keohane E, Smith L, Walenga J. Rodak’s hematology: clinical principles and applications New York City, NY: Elsevier Health Sciences; 2015:p 130
2. Heinicke K, Prommer N, Cajigal J, et al. Long-term exposure to intermittent hypoxia results in increased hemoglobin mass, reduced plasma volume, and elevated erythropoietin plasma levels in man.Eur J Appl Physiol2003;88:535–543
3. Hassanpour SE, Moosavizadeh SM, Fadaei Araghi M, et al. Pulmonary artery pressure in patients with markedly deviated septum candidate for septorhinoplasty.World J Plast Surg2014;3:119–121
4. Sykes JM, Kim JE, Shaye D, et al. The importance of the nasal septum in the deviated nose.Facial Plast Surg2011;27:413–421
5. Boyce J, Eccles R. Do chronic changes in nasal airflow have any physiological or pathological effect on the nose and paranasal sinuses? A systematic review.Clin Otolaryngol2006;31:15–19 6. Ko¨hler D, Dellweg D. Polycythemia. Dtsch Med Wochenschr
2010;135:2300–2303
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Blood Rev2013;27:41–53
8. Boyer L, Chaar V, Pelle G, et al. Effects of polycythemia on systemic endothelial function in chronic hypoxic lung disease.J Appl Physiol 2011;110:1196–1203
9. Sagit M, Korkmaz F, Kavugudurmaz M, et al. Impact of septoplasty on mean platelet volume levels in patients with marked nasal septal deviation.J Craniofac Surg2012;23:974–976
10. Ulu S, Ulu MS, Bucak A, et al. Evaluating the relationship between nasal obstruction and mean platelet volume by using acoustic rhinometry in patients with septum deviation.Rhinology2013;51:
249–252
11. Sahin MS, Kizilirmak D. Changes at mean platelet volume and platelet distribution width levels after septoplasty and its correlation with epworth sleepness scale.J Craniofac Surg2017;28:71–73
12. Oehadian A, Suryadinata H, Dewi S, et al. The role of neutrophyl lymphocyte count ratio as an inflammatory marker in systemic lupus erythematosus.Acta Med Indones2013;45:170–174
13. Olt S. Relationship between thyroid nodules and neutrophil/
lymphocyteratio.Acta Medica Mediterranea2015;31:725–727
Evaluation of the Spatial Position and Correlation of Mandibular Ramus in Skeletal Class III
Patients With Mandibular Asymmetry
Guan-Lin Qu, MS,Jing Xu, MS,and Qing Zhou, PhDy
Purpose: To evaluate the position and bilateral difference of mandibular ramus region, specifically the condyle, sigmoid notch, and mandibular angle in skeletal class III patients with mandibular asymmetry.
Materials and Methods: 3D-CT images were performed in 50 patients with skeletal class III malocclusion. According to the severity of mandibular asymmetry, 22 cases were included in the control group and 28 cases were included in the symmetry group.
The 3D landmarks were measured relative to 6 reference planes and the outcomes among different groups were compared.
Results:There are significant differences in the position of man- dibular ramus region between both sides in the asymmetry group.
The position of condyle was more posterior and internal on the deviated side; and the positions of sigmoid notch and gonion were more posterior, superior, and lateral on the deviated side. Further- more, the degree of mandibular asymmetry was more highly correlated with the height of ramus and the position of mandibular angle than it was with the height of condyle and the position of sigmoid notch.
Conclusion:When evaluating mandibular asymmetry and making surgical plans, the position of mandibular ramus should be taken into consideration.
Key Words:Mandibular asymmetry, mandibular ramus, skeletal class III malocclusion, 3-dimension
S
ymmetric face is considered healthy and attractive.1As people pay more attention to their appearances due to the influence of social media, they are pursuing a better-looking face, in which case, a more symmetric face. Statistically, facial asymmetry has accounted for 25% of orthodontic chief complaint in patients who seek for orthodontic treatments.2 Severt and Proffit showed that facial asymmetry usually occurs in the lower third because ofFrom theDepartment of 1st Orthodontics; andyDepartment of Oral and Maxillofacial Surgery, School of Stomatology, China Medical Univer- sity, Shenyang, China.
Received January 4, 2019.
Accepted for publication February 18, 2019.
Address correspondence and reprint requests to Qing Zhou, PhD, Depart- ment of Oral and Maxillofacial Surgery, School of Stomatology, China Medical University, Shenyang 110002, Liaoning Province, China;
E-mail: [email protected] The authors report no conflicts of interest.
Supplemental digital contents are available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www.jcraniofa- cialsurgery.com).
Copyright#2019 by Mutaz B. Habal, MD ISSN: 1049-2275
DOI: 10.1097/SCS.0000000000005570
The Journal of Craniofacial Surgery Volume 30, Number 5, July 2019 Brief Clinical Studies
#2019 Mutaz B. Habal, MD
e439
Copyright © 2019 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
the character that mandible can move.3 – 5Asymmetry in the lower third of the face often leads to skeletal partial jaw deformity.
Mandibular asymmetry is the main clinical manifestation of partial jaw deformity. It not only affects the appearance of the patients’
facial features but is often accompanied by malocclusion which can cause the temporomandibular joint diseases over a long time.6 Therefore, mandibular asymmetry has received increasing attention from orthodontists and orthopedists.
Accurate treatment undoubtedly depends on accurate diagnosis.
In the past, the measurement and analysis of regions with craniofacial asymmetry were usually performed on 2-dimensional (2D) diagnos- tic tools. As a result, some issues such as distortion, magnification, and superimposition could not be overcome.7,8However, 3-dimen- sional (3D) evaluations can clearly and accurately observe the degree of mandibular deviation which can be used for quantitative diagnosis and analysis of partial jaw deformity.9,10 The measurement and evaluation of the 3-dimensional shape of the mandibular bone are one of the important methods for the diagnosis and treatment design of skeletal mandibular asymmetry.
Many previous studies have demonstrated that there are differ- ences in mandibular morphology between both sides of mandible in patients with facial deformity. These studies have found out that the correlation between the change of mandibular morphology and the degree of mandibular deviation.11But only a few studies focused on spacial position of mandibular ramus region. The main purpose of our study is to investigate by using 3D evaluation, whether there could be any difference found in the position of mandibular ramus region including condyle, sigmoid notch and mandibular angle in skeletal class III patients, either with and without mandibular deviation; and whether there is correlation between the position of mandibular ramus region and the degree of mandibular deviation.
METHODS Subjects and Data Acquisition
This study was a retrospective investigation, which consisted of 50 skeletal class III patients with mandibular asymmetry at the affiliated stomatological hospital of China Medical University in Shengyang, China, from August 2015 to October 2017. All the patients received orthognathic surgery and 3D-CT images were obtained before presurgical orthodontics for the purpose of oper- ative design, thus being used in this study. This study was reviewed and approved by the Ethics Committee of China Medical University Dental Hospital.
The inclusion criteria of study objects were as follows:
(1) The age was more than 18 years old,
(2) ANB<08and an Angle class III molar relationship, (3) The frontal radiograph images showed that there was no
apparent asymmetry in the upper and middle third of the face, (4) No systemic disease, no previous TMJ or orthognathic surgery,
no cleft lip or palate, and no history of facial trauma.
All the study objects were divided into 2 groups which were based on the degree of menton (Me) point shifting from the midsagittal plane (MSP) of face. Machida reported that if Me point deviated from the midsagittal plane more than 4 mm can be classified as mandibular asymmetry.12Similarly, some other studies on facial asymmetry used the same classified criterion between the symmetry and asymmetry groups. Therefore, in this study, patients whose Me point deviated from MSP more than 4 mm were included in the asymmetry group, and patients whose Me point deviated from MSP less than 4 mm were included in the control group. In the asymmetry group, the ‘‘deviated
side’’ was considered as the side of Me point shifting from MSP, and the
‘‘contralateral side’’ referred to the other side except the deviated side.
Image Reconstruction and Analysis
All scans were obtained using a 3-dimensional computed tom- ography scanner (Toshiba Corporation, Tokyo, Japan) at 120 kV tube voltage, 300 mA tube current, woxel size of 0.4 mm, and field of view of 21.119.2 cm. A 20s’ scan was imposed on the patients in the supine position with teeth in intercuspal position.13In order to prevent head deflection; the medial axis of face is consistent with the longitudinal axis of the CT scan. The 3D images were stored in digital images and communication in medicine (DICOM) files and exported to the Mimics software program (Version 17.0, Materi- alise, Leuven, Belgium) to reconstruct a 3D hard-tissue surface model for analysis.
Reference Points and Planes
The reference points on the 3D images were defined as follows (Table 1-SDC, http://links.lww.com/SCS/A505 and Figs. 1a–c and 2a):
The reference planes on the 3D images were defined as follows (Table 2-SDC, http://links.lww.com/SCS/A505 and Fig. 2b and c):
The definitions of the measurements were defined as follows (Table 3-SDC, http://links.lww.com/SCS/A505).
Statistical Analysis
All statistical analyses were performed using a statistical analysis program (SPSS20.0, Chicago, IL). The differences of both sides in each group were calculated by pairedttest. Com- parisons between the 2 groups were performed by using the independentttest. In the control group, there was no statistical
FIGURE 1.A. Po, Porion; Go, Gonion; N, Nasion; Or, Orbitale; Me, Menton. B.
Ba, Basion. C. Co_sup, Superior pole of condyle; Co_ant, Anterior pole of condyle; Co_med, Medial pole of condyle; Co_lat, Lateral pole of condyle.
FIGURE 2.A. Co_pos, Posterior pole of condyle; Cop, Coronoid process; Sn, Sigmoid notch. B. MSP: Midsagittal plane, the plane perpendicular to the FH plane and including N and Ba; FH plane: The plane including both Or and right Po; CP: coronal reference plane, the plane perpendicular to the FH plane and the MSP and including the right Po. C. HPC, horizontal plane of condyle, the plane passing through the Co_ant, Co_med and Co_lat; SPC: Sagittal plane of condyle, the plane passing through the Co_sup, Co_ant and Co_pos; CPC:
Coronal plane of condyle, the plane passing through the Co_sup, Co_lat and Co_med.
Brief Clinical Studies The Journal of Craniofacial Surgery Volume 30, Number 5, July 2019
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#2019 Mutaz B. Habal, MDCopyright © 2019 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
difference between the measured values of both sides of the mandibular ramus (Table 4-SDC, http://links.lww.com/SCS/
A505). So we could compare the mean value of the left and right side in the control group to each side in the asymmetry group respectively. The relationship between the position of mandibular ramus and the degree of mandibular deviation was assessed by Pearson’s correlation analysis. For all the statistical analyses, the level of significance was set to 0.05.
RESULTS
Analysis in Composition of Age and Gender
The 28 patients in the asymmetry group with an average age of 20.9 years (18–31) and 22 patients in the control group with a mean age of 23.1 years (18–34) were included in this study. There was no statistically significant difference between both groups with respect to age by independent samplettest (P¼0.249). 18 males and 10 females were included in the asymmetry group, and 13 males and 9 females were included in the control group. There was no statisti- cally significant difference between both groups in regard to gender byx2test (P¼0.707).
Comparison of Bilateral Measurements in Each Group
As regards the morphology of mandibular ramus region, in the asymmetry group, the height of condyle and ramus on the deviated side was shorter than it was on the contralateral side, and the height of coracoid on the deviated side was longer than it was on the contralateral side. There were no differences between both sides in the control group. In addition, between both sides in the asymmetry group; we found that the position of the condyle was more poster- iorly and internally on the deviated side and the position of the sigmoid notch was more posterior, superior and lateral on the deviated side; furthermore, the position of the mandibular angle was more posterior, superior and lateral on the deviated side.
Whereas there were no positional differences of condyle, sigmoid notch and mandibular angle between both sides in the control group (Table 4-SDC, http://links.lww.com/SCS/A505).
Differences Between Both Sides in Asymmetry Group and the Average of Both Sides in Control Group
The differences between each mandibular ramus in the asym- metry group and the average value of both sides in the control group were compared. And the results indicated that there was a statisti- cally significant difference in the height of condyle, coracoid and mandibular ramus. And in relation to 3D position, there was a significant difference in mandibular angle and sigmoid notch (Table 5-SDC, http://links.lww.com/SCS/A505).
Correlation Between the Bilateral Difference of Asymmetry Group and the Degree of Me Deviation
Correlations between bilateral differences (deviated side minus contralateral side) in measurements of mandibular ramus and the degree of mandibular deviation were analyzed. The results showed a significant correlation between mandibular deviation and the position of mandibular ramus including mandibular angle and sigmoid notch. There was also significant correlation between coronal position of condyle and mandibular deviation, whereas there was no significant correlation between sagittal or horizontal
position of condyle and mandibular deviation (Table 6-SDC, http://
links.lww.com/SCS/A505).
DISCUSSION
The main objective of this study was to examine if there is any difference between both sides in the 3D position of mandibular ramus region, in particular, the condyle, sigmoid notch and man- dibular angle in skeletal class III patients with mandibular asym- metry. We also wanted to make sure there is a correlation between mandibular deviation and the position of condyle, sigmoid notch, and mandibular angle.
There are many causes for mandibular asymmetry. In summary, it can be divided into congenital genetic factors and acquired environmental factors. If the embryo encounters obstacles during development and produces genetic defects, it can lead to cranio- facial asymmetry. Facial asymmetry usually occurs in the lower third of the face. Most scholars believe that congenital genetic factors are rarely relative, and the main causes of mandibular asymmetry are acquired environmental factors.14
Acquired environmental factors include occlusion interference, unilateral chewing habits, malocclusion, temporomandibular joint disorders, and condylar trauma. The most common causes are occlusion interference and temporomandibular joint disorders. If there is occlusion interference in the intercuspal position, the baroreceptors on the periodontal ligament are stimulated. As the signal returns to the central nervous system, it affects the contrac- tion of masticatory muscles and results in a functional malocclu- sion. As time goes on, the shape of condyle transforms adaptively and the mandibular asymmetry exacerbates from functional to skeletal gradually.15The main structure of the mandibular ramus site is composed of condyle, ramus, coracoids, and mandibular angle. Condyle is an important part of temporomandibular joint and it is the center of mandibular growth and reconstruction. The structural and functional abnormalities of condyle can cause the change of mandibular morphology.
The morphology of condyle and mandibular ramus in patients with mandibular asymmetry has been assessed in previous studies.16The results of this study showed that the condyle and mandibular ramus on the deviated side were shorter than contralateral side in asymmetry group, and they were in correspondence with previous results.17 Although the results of this study showed that the coracoid of the deviated side was longer than the contralateral side, the coracoid does not participate in the chewing movement. Also, there is no evidence that there is a relationship between coracoid and mandibular devi- ation. Isberg believed that coracoid is affected by the traction of temporalis, and the long term tension of temporalis of the deviated side may cause the coracoid become longer on the deviated side.18
The functional differences of muscles can adapt to the skeletal units of the craniofacial complex.19 – 21And the morphology of the mandibular angle might transform in spatial position due to the difference existed in muscular activity between the deviated side and the contralateral side.22But the 3D position of the mandibular angle in patients with mandibular asymmetry has not been examined in previous studies. In this study, we found that the position of mandibular angle of asymmetry group was located more posteriorly, superiorly and laterally on the deviated side in com- parison to the contralateral side. The study also showed significant differences in 3-dimension spatial position of sigmoid notch and condyle in patients of asymmetry group. The position of condyle was located more posteriorly and internally on the deviated side, and the position of sigmoid notch was located more posteriorly, superiorly and laterally on the deviated side. In addition, this study showed that there is a significant correlation between the position of mandibular ramus and mandibular deviation.
The Journal of Craniofacial Surgery Volume 30, Number 5, July 2019 Brief Clinical Studies
#2019 Mutaz B. Habal, MD
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Copyright © 2019 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The results of this study showed that bilateral discrepancy in the height of condyle, ramus, and coracoid; the coronal position of condyle head, the position of gonion and the position of sigmoid notch are significantly in connection with the degree of mandibular deviation. But the degree of bilateral difference in the position of condylar head is not higher than the sigmoid notch and mandibular angle. Some studies have shown that different parts of mandible have different growth rates.23 Condyle is the growth center of mandible, and the growth of condyle and mandibular ramus lasted for the longest time. The growth of mandibular body and chin region stopped earlier. Therefore, doctors should think about the discrepancies and characteristics in 3D spatial position of the condyle, sigmoid notch and mandibular angle regions, and take these variations into account during evaluating mandibular asym- metry and making surgical plans for the sake of acquire optimal post-surgical appearances in the patients of mandibular asymmetry.
CONCLUSIONS
This retrospective study found that:
(1) Mandibular asymmetry is related to the position of condyle, mandibular angle, and sigmoid notch.
(2) The degree of asymmetry was more highly correlated with the height of ramus and the position of mandibular angle than it was with the position of the sigmoid notch and the condyle.
Therefore, the position of mandibular ramus region should be considered in evaluating mandibular asymmetry and making treatment plans.
ACKNOWLEDGMENTS
The authors gratefully thank Professor Ming-Liang Yang and Dr Guang-Qi Yan, for sharing their experience during the study process.
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Presentation, Management, and Outcome of Lingual Thyroglossal Duct Cyst in
Pediatric and Adult Populations
Wei Li, MD, Yi-peng Ren, MD, Yue-yi Shi, MS, Lei Zhang, MD, and Rong-fa Bu, MD
Abstract: Lingual thyroglossal duct cysts (LTDCs) are rare congenital anomalies of the neck. The authors described the
From the Department of Oral and Maxillofacial Surgery, Chinese PLA General Hospital, Beijing, China.
Received January 12, 2019.
Accepted for publication February 19, 2019.
Address correspondence and reprint requests to Rong-fa Bu, MD, Department of Oral and Maxillofacial Surgery, Chinese PLA General Hospital. No. 28, Fuxing Road, Haidian District, Beijing 100853, China; E-mail: [email protected]
This work was supported by the National Natural Science Foundation of China (No. 81760200), and the Natural Science Foundation of Inner Mongolia (No. 2017MS0326).
The authors report no conflicts of interest.
Supplemental digital contents are available for this article. Direct URL citations appear in the printed text and are provided in the HTML and PDF versions of this article on the journal’s Web site (www.jcraniofa- cialsurgery.com).
Copyright#2019 by Mutaz B. Habal, MD ISSN: 1049-2275
DOI: 10.1097/SCS.0000000000005522
Brief Clinical Studies The Journal of Craniofacial Surgery Volume 30, Number 5, July 2019
