Шаблоны LeoTheme для Joomla.
GavickPro Joomla шаблоны

Research Article

The Incidence of Temporomandibular Joint Structural Abnormalities in Orthodontic Pretreatment Patients

Jiaqiang Liu1 PH.D, Yi Jiang2 PH.D, Jing Mao3 MD, Yong Wu1 PH.D, Lixia Mao1 MD, Pan Ma4 PH.D, Lunguo Xia1 .D, Liangyan Sun1 MD, Jie Wang1 MD, Jinglei Zhao1 MD, Qinggang Dai1 MD, Bing Fang1* PH.D

1Department of Oral and Cranio-Maxillofacial, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi-Zao- Ju Road, Shanghai 200011, People’s Republic of China
2Department of Stomatology, Chinese PLA General Hospital, No. 28 Fuxing Road, Beijing 100853, People’s Republic of China
3Department of Gynaecology and Obstetrics, Shanghai 1st Maternity and Infant Hospital, 536 Changle Road, Shanghai 200040, People’s Republic of China
4Department of oral implantology, Beijing Stomatological Hospital of Capital Medical Univercity, Tian tan xi li 4, Beijing 100050, People’s Republic of China

*Corresponding author: Dr. Bing Fang, Department of Oral and Cranio-Maxillofacial, Ninth People’s Hospital, Shanghai Jiao Tong University School of Medicine, 639 Zhi-Zao-Ju Road, Shanghai 200011, People’s Republic of China, Tel: +86 21 23271699-5735; Email: braces_dr@hotmail.com

Submitted: 07-16-2015 Accepted: 09-30-2015  Published: 10-07-2015

Download PDF

_________________________________________________________________________________________________________________________

 

Article

 

Abstract

Objectives


Structural variations of the temporomandibular joint (TMJ) will affect orthodontic treatment. So we analyzed common issues of
TMJ structure among patients with different types of malocclusions.

Methods
312 orthodontic pretreatment patients were randomly selected as subjects. Conventional anteroposterior and lateral cephalometric radiographs, panoramic radiographs, TMJ magnetic resonance images were obtained and the subjects’ TMJ structures were assessed.

Results

Among all the 312 pretreatment patients, 206 patients (66.03%) presented with TMJ structural variations, and for male patient Class I patients, 72.97% of skeletal Class II patients, 64.04% of skeletal Class III patients. Horizontal analysis indicated that a varied TMJ structure was present in 78.18% of patients with mandibular deviation to the left, 60.87% of patients without mandibular deviation, 85.19% of patients with mandibular deviation to the right. Vertical analysis revealed that a varied TMJ structure was present in 77.12% of high-angle patients, 56.88% of average-angle patients, 70.59% of low-angle patients.

Conclusions

TMJ structural variations were present in a high proportion of orthodontic pretreatment patients. Although most of these patients did not present clinical symptoms, orthodontists should pay more attention to such potential risk.

Keywords: Orthodontic; Temporomandibular Joint; Malocclusion; Structural Variations

Introduction

Temporomandibular joint (TMJ) disorders constitute a common disease of the oral cavity that is encountered in clinical contexts [1-3]. Moreover, the normality of the TMJ structure is closely related to both occlusal function and orthodontic treatment. This topic has attracted increasing attention from dentists, including orthodontists [4,5]. The normality of the TMJ structure not only affects the development of orthodontic treatment plans but also plays an important role in determining the stability of orthodontic effects and can even influence decisions regarding whether to begin orthodontic treatment [6,7]. However, few domestic or international studies have examined the epidemiology of this disease, especially among the population of orthodontic pretreatment patients. Therefore, in this study, an epidemiological analysis of TMJ structural variations in orthodontic pretreatment patients was performed from multiple perspectives, thereby facilitating an exploration of the overall prevalence of these structural variations in the orthodontic patient population and in different gender groups. In addition, we also evaluated the correlations between TMJ structural variations and malocclusions from the sagittal, horizontal, and vertical directions, with the goal of providing reference data for developing orthodontic treatment programs for clinically treating patients with varied TMJ structures.

Materials and Methods

The study subjects were 312 randomly selected patients who need orthodontic treatment, but have not received orthodontic treatment, from our department during the prior two years. These subjects included 98 males and 214 females and ranged from 10 to 55 years of age, with an average age of 21.17 years. Conventional anteroposterior and lateral cephalometric radiographs, as well as panoramic radiographs, were obtained for the study subjects. Bilateral magnetic resonance images of the subjects’ TMJs in both open and closed positions were acquired, and the subjects’ TMJ structures were assessed. The structure of the TMJs was evaluated. In this study, TMJ structural variations were mainly divided into disc displacement with reduction, disc displacement without reduction, medial disc displacement, lateral disc displacement, joint effusion, and other variations (condylar bone variations, morphological variations, etc.)

Diagnosing criteria

Normal structure of TMJ: In the lateral MRI images of a normal TMJ in the closed position, the articular disc is located at the 11 o’clock position relative to the condyle, with no anteroposterior displacement, bone resorption, joint effusion, or other variations. In the lateral MRI images in the open position, the articular disc is located at the top of the condyle, with no bone resorption, joint effusion, or other variations. Good condylar mobility was observed. In the anteroposterior MRI images of a normal TMJ, the articular disc is located at the top of the condyle, with no medial or lateral displacement and no bone resorption, joint effusion, or other variations.

Disc displacement with reduction: Lateral MRI images in the closed position, the articular disc is located in front of the condyle, with no other variations. In the open position, the articular disc is located at the top of the condyle, with no other variations. Good condylar mobility was observed. In the anteroposterior MRI images, the articular disc position is normal.

Disc displacement without reduction: Lateral MRI images in the closed position, the articular disc is located in front of the condyle, with no other variations. In the open position, the articular disc is also located in front of the condyle, with no other variations. Good condylar mobility was observed. In the anteroposterior MRI images, the articular disc position is normal.

Medial disc displacement: In the anteroposterior MRI images, the articular disc is located inside of the condyle.

Lateral disc displacement: In the anteroposterior MRI images, the articular disc is located outside of the condyle.

Joint effusion: In the MRI images, liquid could be detected.

The diagnosis of each patient was performed by at least three doctors without providing individual information of the patients. Statistics was performed by another doctor.

Results

MRI and X-ray imaging

Magnetic resonance imaging (MRI) can clearly reveal various structural variations of the TMJ [8,9], such as aberrations in the disc-condyle relationship, effusion, and bone variations. MRI is commonly used both domestically and internationally for examination of the TMJ. The complementary data provided by X-ray imaging can be utilized for cephalometric analyses that provide a relatively comprehensive understanding of the condition of this joint. (Figures 1-2)

Figure 1

anatomy fig 4.1
A. Lateral MRI images of a normal TMJ in the closed position. The articular disc is located at the 11 o’clock position relative to the condyle, with no anteroposterior displacement, bone resorption, joint effusion, or other variations.

B. Lateral MRI images of a normal TMJ in the open position. The articular disc is located at the top of the condyle, with no bone resorption, joint effusion, or other variations. Good condylar mobility was observed.

C. Anteroposterior MRI images of a normal TMJ. The articular disc is located at the top of the condyle, with no medial or lateral displacement and no bone resorption, joint effusion, or other variations.

 

anatomy fig 4.2

Figure 2. Conventional anteroposterior and lateral cephalometric radiographs and a panoramic radiograph. No significant variations in the position of the mandibular condylar process or the depicted bones were observed.

General analysis

This section focuses on general analyses of TMJ structural variations among the population of orthodontic pretreatment patients.

Among all 312 orthodontic patients, a varied TMJ structure was present in 206 patients, which accounted for 66.03% of the total patient population. As far as the 206 patients with varied TMJ structures are concerned, 141 patients (68.45%) had bilateral TMJ variations; 176 patients (85.44%) had a varied left TMJ structure, including 35 patients with unilateral left TMJ variations; and 171 patients (83.01%) had a varied right TMJ structure, including 30 patients with unilateral right TMJ variations.

Among the 176 patients with a varied left TMJ structure, medial articular disc displacement was the most common issue, and lateral articular disc displacement was the least common issue, and for the 171 patients with a varied right TMJ structure, joint effusion was the most common issue, and disc displacement with reduction was the least common issue.

The TMJ structural variations in orthodontic pretreatment patients of different genders are indicated in Figure 3. Among all 98 examined male patients, 57 patients (58.16%) had varied TMJ structures. Among all 214 examined female patients, 149 patients (69.63%) had varied TMJ structures. The fourfold table test revealed that p=0.047, indicating that the difference between genders was significant.

anatomy fig 4.3

Figure 3. The incidence of TMJ structural variations in orthodontic pretreatment patients of different genders.

Sagittal analysis

This section focuses on analyses of the relationship between the TMJ and the sagittal maxillary and mandibular positions. In lateral cephalometric radiographs, ANB angles between 0-5 degrees, greater than 5 degrees, and less than 0 degrees are defined as skeletal Class I, skeletal Class II, and skeletal Class III.

An analysis of the TMJ structural variations in populations of orthodontic pretreatment patients with malocclusions with different ANB angles is presented in Figure 4. Among all 312 orthodontic patients, there were 112 skeletal Class I patients, among whom, 68 patients (60.71%) had varied TMJ structures; 111 skeletal Class II patients, among whom, 81 patients (72.97%) had varied TMJ structures; and 89 skeletal Class III patients, among whom, 57 patients (64.04%) had varied TMJ structures. The fourfold table test indicated that p=0.052 for skeletal Class I vs skeletal Class II, p=0.629 for skeletal Class I vs skeletal Class III, and p=0.175 for skeletal Class II vs skeletal Class III.

anatomy fig 4.4

Figure 4. The incidence of TMJ structural variations in orthodontic pretreatment patients with different types of sagittal skeletal malocclusions.

Among all 112 skeletal Class I patients, 68 patients (60.71%) had varied TMJ structures; 40 patients (35.71%) had bilateral variations; 55 patients (49.11%) had left TMJ variations, including 15 patients with unilateral left TMJ variations; and 53 patients (47.32%) had right TMJ variations, including 13 patients with unilateral right TMJ variations.

Among all 111 skeletal Class II patients, 81 patients (72.97%) had varied TMJ structures; 61 patients (54.95%) had bilateral variations; 70 patients (63.06%) had left TMJ variations, including nine patients with unilateral left TMJ variations; and 72 patients (64.86%) had right TMJ variations, including 11 patients with unilateral right TMJ variations.

Among all 89 skeletal Class III patients, 57 patients (64.04%) had varied TMJ structures; 40 patients (44.94%) had bilateral variations; 51 patients (57.30%) had left TMJ variations, including 11 patients with unilateral left TMJ variations; and 46 patients (51.69%) had right TMJ variations, including six patients with unilateral right TMJ variations.

Horizontal analysis

This section focuses on analyses of the relationship between the TMJ structure and the horizontal maxillary and mandibular positions. Mandibular deviation to the left was defined as a left-side bias of more than 2 mm in the mandibular position. Mandibular deviations of 2 mm or less were regarded as normal mandibular positioning, whereas mandibular deviation to the right was defined as a rightside bias of more than 2 mm in the mandibular positioning.

An analysis of the TMJ structural variations in populations of orthodontic pretreatment patients with different types of mandibular deviations is presented in Figure 5. Among all 312 examined orthodontic patients, 55 patients had mandibular deviation to the left, and 43 of these patients (78.18%) had structural TMJ variations. There were 230 patients without mandibular deviation, and 140 of these patients (60.87%) had structural TMJ variations. There were 27 patients with mandibular deviation to the right, and 23 of these patients (85.19%) had structural TMJ variations. The fourfold table analysis revealed that p=0.016 for mandibular deviation to the left vs no mandibular deviation, p=0.452 for mandibular deviation to the left vs mandibular deviation to the right, and p=0.013 for no mandibular deviation vs mandibular deviation to the right.

anatomy fig 4.5

Figure 5. The incidence of TMJ structural variations in orthodontic pretreatment patients with different types of horizontal skeletal malocclusions.

Among all 55 patients with mandibular deviation to the left, 43 patients (78.18%) had TMJ structural variations; 28 patients (50.91%) had bilateral variations; 39 patients (70.91%) had left TMJ variations, including 11 patients with unilateral left TMJ variations; and 34 patients (61.82%) had right TMJ variations, including 6 patients with unilateral right TMJ variations.

Among all 230 patients without mandibular deviation, 140 patients (60.87%) had TMJ structural variations; 93 patients (40.43%) had bilateral variations; 119 patients (51.74%) had left TMJ variations, including 26 patients with unilateral left TMJ variations; and 114 patients (49.57%) had right TMJ variations, including 21 patients with unilateral right TMJ variations.

Among all 27 patients with mandibular deviation to the right, 23 patients (85.19%) had TMJ structural variations; 18 patients (66.67%) had bilateral variations; 18 patients (66.67%) had left TMJ variations, including no cases of patients with unilateral left TMJ variations; and 23 patients (85.19%) had right TMJ variations, including 5 patients with unilateral right TMJ variations.

Vertical analysis

This section focuses on analyses of the relationship between the TMJ structure and the vertical maxillary and mandibular positions. In these analyses, angles between the mandibular plane (MP) and the Frankfort horizontal (FH) of greater than 32 degrees, between 22 and 32 degrees (inclusive), and less than 22 degrees were regarded as high angles, average angles, and low angles, respectively.

An analysis of the TMJ structural variations in populations of orthodontic pretreatment patients with different MP angles is presented in Figure 6. Among all 312 examined orthodontic patients, there were 118 high-angle patients, and 91 of these patients (77.12%) had TMJ structural variations. There were 160 average-angle patients, and 91 of these patients (56.88%) had TMJ structural variations. There were 34 low-angle patients, and 24 of these patients (70.59%) had TMJ structural variations. The fourfold table analysis indicated that p<0.001 for high angle vs average angle, p=0.434 for high angle vs low angle, and p=0.139 for average angle vs low angle.

anatomy fig 4.6

Figure 6. The incidence of TMJ structural variations in orthodontic pretreatment patients with different types of vertical skeletal malocclusions.

Among all 118 high-angle patients, 91 patients (77.12%) had TMJ structural variations; 66 patients (55.93%) had bilateral  variations; 79 patients (66.95%) had left TMJ variations, including  13 patients with unilateral left TMJ variations; and 78 patients (66.10%) had right TMJ variations, including 12 patients with unilateral right TMJ variations.

Among all 160 average-angle patients, 91 patients (56.88%) had TMJ structural variations; 60 patients (37.50%) had bilateral variations; 79 patients (49.38%) had left TMJ variations, including 19 patients with unilateral left TMJ variations; and 72 patients (45.00%) had right TMJ variations, including 12 patients with unilateral right TMJ variations.

Among all 34 low-angle patients, 24 patients (70.59%) had TMJ structural variations; 17 patients (50.00%) had bilateral variations; 18 patients (52.94%) had left TMJ variations, including 1 patient with a unilateral left TMJ variations; and 23 patients (67.65%) had right TMJ variations, including 6 patients with unilateral right TMJ variations.

Discussion

Temporomandibular disorders (TMDs) are common diseases affecting the oral and maxillofacial regions. TMDs are not a single condition but are instead a general term for a group of diseases with identical or similar clinical symptoms. The etiology of these diseases is not fully understood, and they are currently considered multifactorial diseases [10,11]. TMDs typically present with pain in the TMJ and/or masticatory muscles; mandibular movement variations and dysfunction; and clicking, cracking, or other joint noises, among other symptoms. To date, the vast majority of studies have demonstrated that orthodontic treatment is unrelated to the occurrence of TMD, neither causing nor aggravating these disorders. Although certain patients have reportedly experienced joint discomfort and other symptoms during the course of orthodontic treatment, there is a lack of evidence-based medical research to specifically validate this phenomenon. In addition, many orthodontic patients are in a high-risk age group for TMDs, which have high  incidence rates among individuals who are 20-30 years of age. The aforementioned factors greatly contribute to uncertainty in the study of the correlation between TMD and orthodontic treatment. Therefore, it is critical for orthodontists to fully understand the incidences and types of TMDs that may be involved in a case prior to performing orthodontic treatment. In addition, TMJ changes during the course of treatment should be closely monitored.

The results of this study also indicate that MRI techniques can excellently visualize the anatomical structure of the TMJ and can be utilized to generate accurate diagnoses. At present, MRI is widely used in clinical practice [12]. When supplemented by X-ray imaging and clinical examination, MRI can provide a relatively comprehensive understanding of the condition of a patient’s TMJ structure.

The study results indicate that approximately two-thirds of orthodontic pretreatment patients present with variations in TMJ structure. However, in most of these patients, these variations do not produce clinical symptoms but simply represent a potential risk. Nearly 70% of all 206 examined patients with TMJ structural variations presented with bilateral variations. Therefore, when patients seek clinical treatment for unilateral TMJ pain, unilateral popping of the TMJ, or other symptoms, a high level of vigilance should be employed in examining the health status of the TMJ on the asymptomatic side. The left and right TMJ exhibit relatively similar incidence rates of structural variations. However, there are slight differences in the types of variations that occur at the left and right TMJ. Gender also significantly influenced the TMJ structure. Our results revealed that the prevalence of structural TMJ variations was 69.63% among the female patients but only 58.16% among the male patients; this difference was statistically significant. Therefore, in a clinical context, greater attention should be devoted to TMJ problems in female patients than in male patients. With respect to the sagittal analysis results, among all 312 examined orthodontic patients, TMJ structural variations occurred in 60.71% of skeletal Class I patients, 72.97% of skeletal Class II patients, and 64.04% of skeletal Class III patients. In patients of all three skeletal classes, rates of the TMJ structural variations were relatively similar between the left and right side. In addition, all classes of patients mainly presented with bilateral variations. However, there were slight differences in the types of structural variations exhibited by patients of each skeletal class; specific information regarding these differences is provided in the results section of this paper. Horizontal analysis results for all 312 examined patients indicated that 78.81% of patients with mandibular deviation to the left, 60.87% of patients without mandibular deviation, and 85.19% of patients with mandibular deviation to the right had varied TMJ structures. Patients
without mandibular deviation have significantly lower risks of TMJ structural variations than do patients with mandibular deviations. However, there is no significant difference in TMJ structural variations between patients with mandibular deviations to the left and patients with mandibular deviations to the right. Therefore, in a clinical context, vigilance must be devoted to monitoring TMJ structural problems in patients with mandibular deviations. Regardless of whether no mandibular deviation, mandibular deviation to the left, or mandibular deviation to the right was present, the patients mostly presented with simultaneous, bilateral TMJ structural variations. However, patients with different mandibular deviation statuses exhibited slightly different types of TMJ structural variations; the specific differences are presented in the results section of this paper. Vertical analyses of all 312 examined patients revealed that 77.12% of high-angle patients, 56.88% of average-angle patients, and 70.59% of low-angle patients had varied TMJ structures. Thus, relative to average-angle patients, high-angle patients have a significantly higher risk of TMJ structural variations. Therefore, particular attention must be devoted to potential variations in the TMJ structures of high-angle patients. High-, average-, and low-angle patients all mainly presented with simultaneous, bilateral TMJ structural variations. However, these patients exhibited slightly different types of structural variations; the specific differences are presented in the results section of this paper.

References

 References

1.Abrahamsson C, Henrikson T, Nilner M, Sunzel B, Bondemark L et al. TMD before and after correction of dentofacial deformities by orthodontic and orthognathic treatment. Int J Oral Maxillofac Surg. 2013, 42(6): 752-758.

2.Amaral Rde O, Damasceno NN, de Souza LA, Devito KL. Magnetic resonance images of patients with temporomandibular disorders: Prevalence and correlation between disk morphology and displacement. Eur J Radiol. 2013, 82(6): 990-994.

3.Badel T, Marotti M, Pavicin IS, Basić-Kes V. Temporomandibular disorders and occlusion. Acta Clin Croat. 2012, 51(3): 419-424.

4.Galhardo AP, da Costa Leite C, Gebrim EM, Gomes RL, Mukai MK et al. The correlation of research diagnostic criteria for temporomandibular disorders and magnetic resonance imaging: a study of diagnostic accuracy. Oral Surg Oral Med Oral Pathol Oral Radiol. 2013, 115(2): 277-284.

5.Imanimoghaddam M, Heravi F, Madani AS, Mohammadi A, Maruzi P. Evaluation of the relationship between vertical facial height and the morphology of the temporomandibular joint in skeletal class 3 patients. J Calif Dent Assoc. 2012, 40(11): 871-876.

6.Koh KJ, Park HN, Kim KA.Relationship between anterior disc displacement with/without reduction and effusion in temporomandibular disorder patients using magnetic resonance imaging.Imaging Sci Dent. 2013, 43(4):245-251.

7.Kuroda S, Kuroda Y, Tomita Y, Tanaka E. Long-term stability of conservative orthodontic treatment in a patient with rheumatoid arthritis and severe condylar resorption. Am J Orthod Dentofacial Orthop. 2012, 141(3): 352-362.

8.Murphy MK, MacBarb RF, Wong ME, Athanasiou KA.Temporomandibular disorders: a review of etiology, clinical management, and tissue engineering strategies.Int J Oral Maxillofac Implants. 2013, 28(6):393-414.

9.Nelson G, Ahn HW, Jeong SH, Kim JS, Kim SH, Chung KR. Three-dimensional retraction of anterior teeth with orthodontic miniplates in patients with temporomandibular disorder. Am J Orthod Dentofacial Orthop. 2012, 142(5): 720-726.

10. Savakkanavar MB, Sridhar S, Dinesh D, Girish KS, Ramesh GC. Association of temporomandibular joint dysfunction, condylar position and dental malocclusions in Davangere population. J Contemp Dent Pract. 2012, 13(4): 528-533.

11.Sharma S, Gupta DS, Pal US, Jurel SK. Etiological factors of temporomandibular joint disorders. Natl J Maxillofac Surg. 2011, 2(2): 116-119.

12.Weiler RM, Santos FM, Kulic MA, De Souza Lima MP, Pardini SR et al. Prevalence of signs and symptoms of temporomandibular dysfunction in female adolescent athletes and non-athletes. Int J Pediatr Otorhinolaryngol. 2013, 77(4): 519-524.

Cite this article: Fang B. The Incidence of Temporomandibular Joint Structural Abnormalities in Orthodontic Pretreatment Patients . J J Anatomy. 2015, 1(1): 004.

Contact Us:
9600 GREAT HILLS
TRAIL # 150 W
AUSTIN, TEXAS
78759 ( TRAVIS COUNTY)
E-mail : info@jacobspublishers.com
Phone : 512-400-0398