Evaluation of condyle position in patients with Angle Class I, II, and III malocclusion using cone-beam computed tomography panoramic reconstructions

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https://doi.org/10.1007/s11282-018-0326-z ORIGINAL ARTICLE

Evaluation of condyle position in patients with Angle Class I, II, and III malocclusion using cone-beam computed tomography panoramic reconstructions

Aslıhan Akbulut¹ · Delal Dara Kılınç²

Received: 20 November 2017 / Accepted: 10 January 2018

Abstract

Objectives This study was performed to compare the positions of the right and left condyles between male and female patients with different Angle malocclusions using cone-beam computed tomography (CBCT) panoramic reconstructions.

Methods The CBCT images of 60 patients (age of 18–37 years) were retrospectively evaluated. The patients were divided according to their Angle malocclusion classifications (Angle Classes I, II, and III). The condyle-to-eminence, condyle-to- fossa, and condyle-to-meatus distances were measured digitally using i-CAT software.

Results The left and right condyle-to-fossa distances were the most variable parameters among the Angle classes. The right condyle-to-eminence and right condyle-to-fossa distances were significantly different among the classes. Male patients seemed to have a greater condyle-to-fossa distance on the right side in both the Class I and III groups. The mean distance from the condyle to eminence, condyle to fossa, and condyle to meatus on the right side was the greatest in the Angle Class II group.

Conclusions In all three types of malocclusion (Angle Classes I, II, and III), the condyles on both the right and left sides were not exactly symmetric or centrally located within the glenoid fossa. This work emphasizes the differences in the condyle position between male and female patients. Furthermore, the symmetry and centricity of the condyles are not dependent on the patient’s sex or type of malocclusion.

Keywords Condyle position · Temporomandibular joint · Panoramic · CBCT · Ricketts

Introduction

The temporomandibular joint (TMJ) must be considered when planning orthodontic, prosthetic, or surgical treatment [1]. Optimal positioning of the condyles in the glenoid fossa is one of the most important indications of a functional and well-balanced dentofacial relationship [2, 3].

In addition to the clinician’s proficiency, clear imaging support is an essential parameter for a correct diagnosis [4].

Various techniques of radiographic imaging of the TMJ have

been suggested for diagnosing pathologies of the TMJ and related tissues. Such techniques include axially corrected tomograms, conventional computed tomography (CT), and cone-beam CT (CBCT) [5, 6]. Ricketts [7] was the first to suggest the use of tomographic measurements for assessment of the condylar position on transcranial radiographs.

Conventional CT images are obtained in the supine position; therefore, errors may occur when evaluating the position of the condyles in the fossa because of the position of the patient, while the radiograph is being taken. In contrast, CBCT images are obtained in an upright position, which is an advantage over conventional CT images [5]. CT imaging allows the researcher to clearly visualize the relevant structures with no superimposition of related tissues [8, 9]

and to determine the real dimensions of the structures that are being analyzed with theoretically zero distortion [10, 11]. Moreover, the hard tissues of the TMJ can be optimally examined by CBCT images [5] with 87.5–96.0% sensitiv- ity in determining the presence of surface degeneration [3].

* Delal Dara Kılınç

[email protected]; [email protected]

1 Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Istanbul Medipol University, Atatürk Blv. No.

27, Unkapanı, Fatih, 34083 Istanbul, Turkey

2 Department of Orthodontics, Faculty of Dentistry, Istanbul Medipol University, Atatürk Blv. No. 27, Unkapanı, Fatih, 34083 Istanbul, Turkey

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A relationship has been found between the functional loading of the TMJ and the joint morphology [7, 8]. Previ- ous studies have shown that the shape of the condyle and glenoid fossa can differ in various types of malocclusions [12–16]. A spatial change of the condyle in the glenoid fossa may result in disc derangements [17, 18]. In contrast, some other studies have shown no significant correlation between the TMJ morphology and type of malocclusion [17, 19–21].

The presence of asymmetry in the shape, size, and condylar position of the same subject’s left and right TMJ has been suggested [17, 22, 23]. Furthermore, the position of the condyles may naturally differ within the same individual [5].

The purpose of this study was to evaluate and compare the positions of the right and left condyles in the glenoid fossa between male and female patients with malocclusions of different Angle classes using CBCT images of the TMJ.

Materials and methods

The ethics committee of Istanbul Medipol University approved this retrospective study (Approval Number: 211- 23/06/2017). The CBCT images of the study were selected from the digital archive of the Istanbul Medipol University, Faculty of Dentistry, Department of Oral and Maxillofacial Radiology.

Sixty CBCT images of 60 patients that had been taken for other dental purposes were retrospectively evaluated.

The patients were divided into 3 groups of 20 patients each.

Their dental malocclusions were classified according to the Angle classification system (Angle Classes I, II, and III) by an orthodontist with 10 years of clinical experience. The patients were aged 18–37 years, had full permanent denti- tion, were not undergoing orthodontic treatment when the CBCT images were taken, had no TMJ disorders, had no history of TMJ trauma, had no craniofacial deformities, had no parafunctional habits, did not have a one-sided chewing habit, and had no systemic diseases.

The CBCT images were taken with an i-CAT 17–19 Imaging System (Imaging Sciences International, Inc., Hatfield, PA, USA). Every CBCT image was taken using

a strict, standardized scanning protocol. The patients were seated in a vertical position on the CBCT machine and stabi- lized with a head support, strap, and chin cup. The occlusal plane was horizontal, and the patients were monitored to ensure that they remained motionless throughout the dura- tion of scanning (14.7 s). All volumes were acquired at 120 kVp and 20.27 mAs using a 16- × 6-cm field of view and 0.25 voxel. The kV and mA parameters were automati- cally determined from scout views obtained with the i-CAT 17–19 Imaging System. The measurements were evaluated by panoramic reconstruction of CBCT images of the right and left condyle regions. The CBCT images were clear and symmetrical, and none were distorted or blurred. The software within the i-CAT 17–19 Imaging System was used to measure all parameters in this study.

All constructions and measurements were performed on a 24-inch in-plane switching panel color-active matrix thin-film-transistor liquid-crystal display (U2410 LCD monitor; Dell, Round Rock, TX, USA) with a resolution of 1920 × 1200 at 60 Hz and 0.27- × 0.27-mm pixel pitch.

All tomographic images were examined in a dark room using the same notebook (Intel^® Core™2 Duo CPU E6400, 2.13 GHz, 2 MB, GeForce GTX 470, 24-inch TFT LCD monitor, 3 GB memory, Windows XP Professional operat- ing system; Intel Corporation, Santa Clara, CA, USA). The images were taken by the same technician under the same conditions, while the patient’s head position was oriented in the Frankfort horizontal plane. The images were taken at centric occlusion in maximum dental intercuspation.

To obtain panoramic reconstructions, the reference contour lines were determined by selecting the maxilla and man- dible from the manual curve settings option. By clicking on the contour line, the anterior point was centered on the midline, with two adjacent points on either side near the anterior point. The points were placed a few teeth away from the anterior center. The next two points were brought closer together to show the molar teeth and the condyles. This is how a panoramic curve is traced on CBCT images.

The positions of the condyles in the fossa were analyzed using the method described by Ricketts in the previous studies [7, 24] (Fig. 1). The anatomical landmarks determined

Fig. 1 Measured distances according to Ricketts

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for this method and the distances measured using these landmarks to perform the calculations are shown in Table 1.

Notably, patients with spatial variations in these reference structures were excluded from the study.

A researcher with 10 years of experience (A.A.) performed the digital measurements using the i-CAT software.

(Fig. 2). In the first stage, the researcher performed ten ran- dom measurements until the method was mastered. After the researcher had calibrated the method, 60 measurements were performed in 6 days (10 on each day) to eliminate fatigue error. The same researcher evaluated 20 randomly selected images 1 week apart to achieve reliability of the measurements.

Statistical analysis

Data processing and statistical analysis were performed using IBM SPSS Statistics 22 (IBM SPSS Statistics V23; IBM Corp., Armonk, NY, USA). Conformity of the

parameters to a normal distribution was evaluated by the Shapiro–Wilk test. In addition to performing a descriptive statistical analysis (mean, standard deviation, and fre- quency), one-way analysis of variance was used to evaluate quantitative data and parameters showing a normal distribution, and Tukey’s honestly significant difference test was used to determine the differential group. Student’s t test was used for intergroup comparisons of parameters with a normal distribution. The paired-sample t test was used to compare quantitative data with a normal distribution between the left and right sides. The Chi-square test was used to compare qualitative data.

The level of statistical significance used for the tests was p < 0.05. Intrarater reliability was evaluated by the intraclass coefficient (ICC). The images were evaluated 1 week apart by the same researcher. The results were found to be reliable (p < 0.05). G*Power analysis was used for a priori power analysis, which showed that a minimum of 18 samples was needed in each group with a power of 0.80 and α value of

Table 1 Reference points and measured distances in the sagittal plane

Points

Chs. Most superior point of the condylar head in the sagittal view

Gfd. Deepest point in the glenoid fossa

Chp. Most posterior point of the condylar head in the sagittal view Pap. Most anterior point of the anatomical portion

Cae. Most anterior point of the condylar head looking toward the eminence Epc. Most posterior point of the posterior eminence wall looking toward

the condylar head Measured distances (Fig. 2)

Chs–Gfd Superior distance, from Chs to Gfd (condyle to fossa) Chp–Pap Posterior distance, from Chp to Pap (condyle to meatus) Cae–Epc Anterior distance, from Cae to Epc (condyle to eminence)

Fig. 2 Cone-beam computed tomography image showing the measured structures and distances

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0.05. Data from preliminary studies were used as the basis of the power analysis.

Results

The mean age of the 60 patients in this study was 22.07 ± 5.47 years. The 60 patients comprised 24 (40%) males and 36 (60%) females. The descriptive statistics of sex and age among patients with Angle Class I, II, and III malocclusions are shown in Table 2. There was no statistically significant difference in the mean age among the Angle classes (p > 0.05). There was also no statistically significant difference in the sex distribution among the Angle classes (p > 0.05).

The mean distance from the right condyle to eminence was the greatest in patients with Angle Class I malocclusion, while that on the left side was greatest in patients with Angle Class II malocclusion. The mean distance from the right condyle to fossa was the greatest in patients with Angle Class II malocclusion, while that on the left side was the greatest in patients with Angle Class II malocclusion. The mean distance from the right condyle to meatus was the greatest in patients with Angle Class II malocclusion, while that on the left side was the greatest in patients with Angle Class II malocclusion (Table 3).

There was no significant difference in the mean distance from the condyle to the eminence on the right and left sides among the Angle classes (p > 0.05) (Table 4). However, the mean distance from the condyle to the fossa on the right and left sides was significantly different among the Angle classes (p = 0.021, p < 0.05). Paired comparisons showed that the mean distance from the right condyle to fossa was significantly greater in patients with Angle Class II than III malocclusion (p = 0.017, p < 0.05). In contrast, there was no statistically significant difference in the distance from the right condyle to fossa between the other classes (p > 0.05).

In addition, there was no statistically significant difference in the distance from the left condyle to fossa among the Angle classes (p > 0.05). Finally, there was no statistically significant difference in the distance from the condyle to the meatus on the right and left sides among the Angle classes (p > 0.05).

Table 5 shows that in male patients; there was a statistically significant difference in the mean distance from the right condyle to eminence among the Angle classes (p = 0.026, p < 0.05). Paired comparisons showed that the

Table 2 Evaluation of age and sex among the classes

Data are present as mean ± standard deviation or n (%)

1 One-way analysis of variance

2 Chi-square test

Class I Class II Class III p

Age (years) 22.15 ± 5.69 21.90 ± 5.17 22.15 ± 5.82 0.987¹ Sex

Male 9 (45%) 6 (30%) 9 (45%) 0.535²

Female 11 (55%) 14 (70%) 11 (55%)

Table 3 Distances from condyle to meatus, condyle to fossa, and condyle to eminence: right and left condyle parameters among the classes

Data are presented as mean ± standard deviation and minimum–maximum R right, L left

Class I Class II Class III

Condyle to eminence (mm)

R 1.34–4.79 2.53 ± 0.84 1.28–4.37 2.35 ± 0.79 1.26–3.40 2.06 ± 0.60 L 1.12–3.85 2.21 ± 0.76 1.03–3.90 2.36 ± 0.80 1.25–3.41 1.97 ± 0.59 Condyle to fossa (mm)

R 1.27–3.91 2.63 ± 0.74 0.91–3.76 2.84 ± 0.67 1.02–3.50 2.21 ± 0.70 L 1.50–4.87 2.93 ± 0.97 1.25–5.71 3.00 ± 1.01 1.42–3.78 2.36 ± 0.69 Condyle to meatus (mm)

R 2.40–8.73 5.93 ± 1.42 3.24–8.00 6.09 ± 1.26 2.79–8.99 5.84 ± 1.77 L 3.26–9.01 6.03 ± 1.52 4.48–8.98 6.58 ± 1.32 4.39–9.74 6.34 ± 1.49 Table 4 Right and left condyle-to-meatus, condyle-to-fossa, and condyle-to-eminence parameters among the classes

Data are presented as mean ± standard deviation

*p < 0.05, one-way analysis of variance

Class I Class II Class III p

Right 2.53 ± 0.84 2.35 ± 0.79 2.06 ± 0.60 0.150 Left 2.21 ± 0.76 2.36 ± 0.80 1.97 ± 0.59 0.246 Condyle to fossa (mm)

Right 2.63 ± 0.74 2.84 ± 0.67 2.21 ± 0.70 0.021*

Left 2.93 ± 0.97 3.00 ± 1.01 2.36 ± 0.69 0.53 Condyle to meatus (mm)

Right 5.93 ± 1.42 6.09 ± 1.26 5.84 ± 1.77 0.863 Left 6.03 ± 1.52 6.58 ± 1.32 6.34 ± 1.49 0.494

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mean distance from the right condyle to eminence was significantly greater in Angle Class I than III (p = 0.020, p < 0.05). However, there was no statistically significant difference in the mean distance from the right condyle to eminence between the other Angle classes (p > 0.05). Fur- thermore, there was no statistically significant difference in the mean distance from the left condyle to eminence among the Angle classes (p > 0.05). In addition, there was no statistically significant difference in the mean distance from the condyle to fossa or condyle to meatus on the right and left sides among the classes (p > 0.05). In female patients, there was no statistically significant difference in the mean distance from the condyle to eminence, condyle to fossa, or condyle to meatus on the right and left sides among the classes (p > 0.05). In contrast, there was a statistically significant difference in the mean distance from the right condyle to fossa among the classes (p = 0.018, p < 0.05). Paired comparisons showed that the mean distance from the right condyle to fossa was significantly greater in Class II than III samples (p = 0.014, p < 0.05). There was no statistically significant difference in the mean distance from the right condyle to fossa between the other classes (p > 0.05).

Table 6 shows that in Class I samples, there was no statistically significant difference in the mean distance from

the condyle to eminence on the right and left sides between males and females (p > 0.05). The mean distance from the right condyle to fossa was significantly greater in male than female patients (p = 0.037, p < 0.05). There was no statistically significant difference in the mean distance from the left condyle to fossa between males and females (p > 0.05).

Finally, in Class I samples, there was no statistically significant difference in the mean distance from the right condyle to meatus between males and females (p > 0.05). The mean distance from the left condyle to meatus was significantly greater in males than females (p = 0.018, p < 0.05). In Class II samples, there was no significant difference in the mean distance from the condyle to eminence, condyle to fossa, or

Table 5 Evaluation of right and left condyle-to-eminence, condyle- to-fossa, and condyle-to-meatus parameters among classes in males and females separately

*p < 0.05, one-way analysis of variance

Sex Class I Class II Class III p

Male

Right 2.84 ± 0.92 2.39 ± 0.41 1.96 ± 0.31 0.026*

Left 2.46 ± 0.61 2.42 ± 0.67 2.29 ± 0.54 0.827 Condyle to fossa (mm)

Right 3.00 ± 0.66 3.17 ± 0.43 2.61 ± 0.63 0.192 Left 3.27 ± 0.91 3.32 ± 0.81 2.67 ± 0.75 0.229 Condyle to meatus (mm)

Right 6.49 ± 1.09 6.87 ± 0.50 6.21 ± 1.91 0.667 Left 6.89 ± 1.40 7.07 ± 1.16 6.74 ± 1.46 0.897 Female

Right 2.27 ± 0.71 2.34 ± 0.92 2.15 ± 0.77 0.843 Left 2.00 ± 0.83 2.33 ± 0.87 1.71 ± 0.52 0.150 Condyle to fossa (mm)

Right 2.32 ± 0.68 2.71 ± 0.72 1.89 ± 0.60 0.018*

Left 2.65 ± 0.97 2.87 ± 1.08 2.10 ± 0.55 0.122 Condyle to meatus (mm)

Right 5.47 ± 1.54 5.76 ± 1.36 5.53 ± 1.68 0.881 Left 5.34 ± 1.27 6.37 ± 1.37 6.02 ± 1.50 0.192

Table 6 Assessment of right and left condyle-to-meatus, condyle- to-fossa, and condyle-to-eminence parameters separately in classes between males and females

*p < 0.05, Student’s t test

Class Sex p

Male Female

Class I

Right 2.84 ± 0.92 2.27 ± 0.71 0.136

Left 2.46 ± 0.61 2.00 ± 0.83 0.188

Condyle to fossa (mm)

Right 3.00 ± 0.66 2.32 ± 0.68 0.037*

Left 3.27 ± 0.91 2.65 ± 0.97 0.161

Condyle to meatus (mm)

Right 6.49 ± 1.09 5.47 ± 1.54 0.112

Left 6.89 ± 1.40 5.34 ± 1.27 0.018*

Class II

Right 2.39 ± 0.41 2.34 ± 0.92 0.898

Left 2.42 ± 0.67 2.33 ± 0.87 0.817

Right 3.32 ± 0.81 2.87 ± 1.08 0.165

Left 3.17 ± 0.43 2.71 ± 0.72 0.369

Right 6.87 ± 0.50 5.76 ± 1.36 0.071

Left 7.07 ± 1.16 6.37 ± 1.37 0.283

Class III

Right 1.96 ± 0.31 2.15 ± 0.77 0.466

Left 2.29 ± 0.54 1.71 ± 0.52 0.025*

Right 2.61 ± 0.63 1.89 ± 0.60 0.017*

Left 2.67 ± 0.75 2.10 ± 0.55 0.065

Right 6.21 ± 1.91 5.53 ± 1.68 0.413

Left 6.74 ± 1.46 6.02 ± 1.50 0.295

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condyle to meatus on the right and left sides between males and females (p > 0.05). In Class III samples, there was no statistically significant difference in the mean distance from the condyle to eminence or condyle to meatus on the right and left sides between males and females (p > 0.05). The mean distance from the left condyle to eminence was significantly greater in males than females (p = 0.025, p < 0.05).

The mean distance from the right condyle to fossa was significantly greater in males than females (p = 0.017, p < 0.05).

Finally, there was no statistically significant difference in the mean distance from the left condyle to fossa between males and females (p > 0.05).

Table 7 shows more comparisons between the right and left sides. In Class I samples, there was no statistically significant difference in the mean distance from the condyle to eminence, condyle to fossa, or condyle to meatus between the left and right sides (p > 0.05). In Class II samples, there was no statistically significant difference in the mean distance from the condyle to eminence or condyle to meatus between the left and right sides (p > 0.05). The mean distance from the condyle to fossa was significantly greater on the right than left side (p = 0.015, p < 0.05). In Class III samples, there was no statistically significant difference in the mean distance from the condyle to eminence, condyle to fossa, or condyle to meatus between the left and right sides (p > 0.05).

Finally, the results of the methodological error analysis are shown in Table 8. The ICC was statistically significant in all measurements. The results of the ICC analysis showed that the measurements could be repeated with a non-significant error that would not affect the results. The systemic intra-examiner error was evaluated at p < 0.05 and found to

be statistically significant. As shown in Table 8, the ICC measurement indicated good reliability with a mean ICC of 1.

Discussion

The effect of occlusion on the morphology of the TMJ is still controversial. Some previous studies have stated that there is a relationship between the TMJ and occlusion, while others have shown no correlation between malocclusions and TMJ structure [15, 16].

Conventional CT imaging allows for clear examination of the related areas of interest, and its dimensions are very close to the real dimensions of the TMJ structure. Never- theless, CBCT is a better choice for evaluating the TMJ in orthodontic practice because of its high-resolution imaging, reliability, and 40% less radiation than conventional CT [23].

A thorough understanding of the nature and structure of the TMJ allows clinicians to provide better treatment planning and diagnosis. The TMJ must be considered in every respect to facilitate construction of well-balanced dentofacial relationships [7, 24–28]. Laminographic images, which were first used by Ricketts [7, 24] to evaluate condyle positions, displayed minimum distortion. As a new and prefer- able imaging method, CBCT may be used to evaluate the osseous components of the TMJ and provide real-size three- dimensional images in a 1:1 anatomical relationship [29, 30].CBCT scanning is a reliable, fast, noninvasive, and effec- tive way of imaging TMJ structures. Furthermore, CBCT imaging enables researchers to evaluate linear and angular values [6, 11, 31]. In the present study, CBCT images were used to analyze the positions of the condyles in the glenoid fossa using the method previously described by Ricketts [7, 24].

Table 7 Assessment of condyle to meatus, condyle to fossa, and condyle to eminence parameters separately in the classes between right and left sides

*p < 0.05, paired-samples t test

Class Right Left p

Class I

Condyle to eminence (mm) 2.53 ± 0.84 2.21 ± 0.76 0.084 Condyle to fossa (mm) 2.63 ± 0.74 2.93 ± 0.97 0.111 Condyle to meatus (mm) 5.93 ± 1.42 6.03 ± 1.52 0.631 Class II

Condyle to eminence (mm) 2.35 ± 0.79 2.36 ± 0.80 0.991 Condyle to fossa (mm) 2.84 ± 0.67 3.00 ± 1.01 0.015*

Condyle to meatus (mm) 6.09 ± 1.26 6.58 ± 1.32 0.116 Class III

Condyle to eminence (mm) 2.06 ± 0.60 1.97 ± 0.59 0.556 Condyle to fossa (mm) 2.21 ± 0.70 2.36 ± 0.69 0.191 Condyle to meatus (mm) 5.84 ± 1.77 6.34 ± 1.49 0.071

Table 8 Evaluation of methodological error

*p < 0.05

Intraclass correla-

tion coefficient 95% confidence interval p Lower limit Upper limit Condyle to eminence (mm)

Right 1.000 1.000 1.000 0.000*

Left 1.000 1.000 1.000 0.000*

Right 1.000 1.000 1.000 0.000*

Left 1.000 1.000 1.000 0.000*

Right 1.000 1.000 1.000 0.000*

Left 1.000 1.000 1.000 0.000*

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Our results showed that in all three types of malocclusions (Angle Class I, II, and III), the condyles did not exhibit symmetric centralization in the glenoid fossa on either the left or right side of the samples. There was a significant difference in the mean distance from the condyle to fossa on the right and left sides among the Angle classes (p = 0.021, p < 0.05). Similar to our study, Vitral et al. [22] observed asymmetric positioning of the left and right condyles of Class II, Division 1 samples in their study. Rodrigues et al.

[16] found statistically significant differences between the right and left sides of Class II, Division 1 samples, but there was no statistically significant difference between the two sides in Class III samples.

In the present study, there was a statistically significant difference in the mean distance from the right condyle to fossa among the classes (p = 0.018, p < 0.05) and a statistically significant difference in the mean distance from the right condyle to eminence among the classes (p = 0.026, p < 0.05). These results indicate an overall asymmetric positioning of the condyle in the fossa among the classes. In accordance with our results, Cohlmia et al. [20] reported that left condyle was positioned more anteriorly than the right condyle in different types of dental and skeletal malocclusion samples.

Cohlmia et al. [20], Pullinger et al. [17], and Vitral et al.

[23] observed non-concentricity of the condyles in different types of malocclusions. Cohlmia et al. [20] stated that asymmetric condyle positions was a norm of the population. Katsavrias and Halazonetis [14] reported differences in the shape of the condyle and mandibular fossa in different types of malocclusions. In contrast, some studies have shown remarkable symmetry of the left and right condyles between different types of malocclusions [3, 15, 22].

In a recent study, Caruso et al. [32] stated that the condyle sizes are not different between the two sides of the face in young adult subjects if no facial asymmetry is present.

Ganugapanta et al. [3] evaluated the condylar positions of vertical, normal, and horizontal growers and suggested that there was a change in the position of the condyle in the vertical grower group when compared with the normal and horizontal grower groups. Arieta-Miranda et al. [2] stated that the condyles in the Class II and III groups had a shorter condyle to fossa distance than the condyles in the Class I group. Other studies have also shown that the condyles in skeletal Class III samples were located more superiorly [7, 14, 24]. In the present study, we found that the mean distance from the condyle to fossa was significantly shorter on the right than left in Class II samples (p = 0.015, p < 0.05).

Al-Rawi et al. [33] found statistically significant differences in the superior joint space, lateral joint space, and anteroposterior and mediolateral condyle distances between males and females among patients with TMJ disorders and normal controls.

In the present study, the mean distance from the right condyle to fossa was significantly greater in male than female patients with Angle Class I malocclusion (p = 0.037, p < 0.05). The mean distance from the left condyle to meatus was significantly greater in male than female patients with Class I malocclusion (p = 0.018, p < 0.05). The mean distance from the left condyle to eminence was significantly greater in male than female patients with Class III malocclusion (p = 0.025, p < 0.05). Again, the mean distance from the right condyle to fossa was significantly greater in male than female patients with Class III malocclusion (p = 0.017, p < 0.05). In accordance with our findings, Al-Rawi et al.

[33] reported that the distance from the condyle to fossa was greater in males than females.

In conclusion, the distance from the condyle to fossa on both the left and right sides was the most variable parameter among the Angle classes. The distances from the right condyle to eminence and right condyle to fossa were significantly different among the Angle classes. Males seemed to have a greater condyle-to-fossa distance on the right side in both the Class I and III groups. In all three types of malocclusion (Classes I, II, and III), the condyles did not show definitive symmetry in the glenoid fossa on either the left or right side. In all three types of malocclusion (Angle Class I, II, and III), the condyles did not exhibit exact symmetric centralization in the glenoid fossa in either males or females or on either the left or right side of the samples.

Compliance with ethical standards

Conflict of interest Aslıhan Akbulut and Delal Dara Kılınç declare that they have no conflict of interest.

Human rights statements All procedures followed were in accordance with the ethical standards of the responsible committee on human experimentation (institutional and national) and with the Helsinki Dec- laration of 1964 and later versions.

Informed consent Informed consent was obtained from all patients for being included in the study.

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