Condylar volume and surface in Caucasian young adult subjects

A randomized controlled clinical trial of concentrated growth factor combined with sodium hyaluronate in the treatment of temporomandibular joint osteoarthritis

OBJECTIVE

To investigate the effect of concentrated growth factor (CGF) combined with sodium hyaluronate (SH) on temporomandibular joint osteoarthritis (TMJOA).

METHODS

Sixty patients with TMJOA who were diagnosed by cone-beam computed tomography (CBCT) between March 2020 and March 2023 at the Stomatological Hospital of Xi'an Jiaotong University were randomly divided into a control group (n = 30) and an experimental group (n = 30). The patients in the experimental group were treated with CGF + SH, and those in the control group were treated with SH only. The visual analogue scale (VAS) score indicating pain in the temporomandibular joint (TMJ) area; the Helkimo Clinical Dysfunction Index (Di); and changes in condylar CBCT at the first visit and 2 weeks, 3 months and 6 months after treatment were recorded. The CBCT data of the patients in the experimental and control groups were collected, and the three-dimensional CBCT image sequences were imported into Mimics Medical 19.0 software in DICOM format for condylar reconstruction.

RESULTS

The VAS scores at 2 weeks, 3 months and 6 months after treatment were significantly lower in the experimental group than in the control group (P < 0.05), and the pain in the experimental group was significantly relieved. The Di was significantly lower in the experimental group than in the control group (P < 0.05), and the clinical function of the TMJ improved. After treatment, the CBCT score was significantly lower in the experimental group than in the control group (P < 0.05), and the condylar bone cortex was obviously repaired. Observation of the condylar bone cortex by three-dimensional reconstruction showed the same results as those obtained by CBCT.

CONCLUSION

CGF combined with SH is effective in the treatment of TMJOA and can improve muscle pain, TMJ pain, Impaired TMJ function, Impaired range of movement, Pain on movement of the mandible and promote bone repair.

THE REGISTRATION NUMBER (TRN)

ChiCTR2400082712.

THE DATE OF REGISTRATION

April 5, 2024.

Comparison of temporomandibular joints in relation to ages and vertical facial types in skeletal class II female patients: a multiple-cross-sectional study

BACKGROUND

The temporomandibular joint (TMJ) is closely related to the dynamic balance and stability of mandibular function and orthodontic treatment. Skeletal class II female patients are thought to be at high risk for TMJ disease. The relationship between the TMJ and craniofacial structures is still controversial. This study compared the morphology and position of the TMJ in skeletal class II adolescents and adults with various vertical facial types using cone-beam computed tomography (CBCT).

MATERIALS AND METHODS

A total of 117 skeletal class II patients were divided into three groups according to the FH-GoGn angle (hypodivergent, normodivergent and hyperdivergent), with 40 class I normodivergent patients serving as controls. Each group contained two age subgroups (adolescents: 11-14 years old, adults: 18-35 years old). The size (condylar length, height, long and short axis diameter, glenoid fossa width and depth) and shape (condylar neck inclination, condylar head angle and long axis angle, articular eminence inclination) of the condyle and fossa, joint space (anterior, superior, posterior, mesial and lateral), and position of the fossa (vertical, transverse, and anteroposterior distance) and condyle were measured and compared using CBCT.

RESULTS

Class II hypodivergent patients exhibited the greatest condylar length, height, and long- and short-axis diameter; steepest articular eminence; deepest fossa depth; largest superior, mesial and lateral joint spaces; and highest fossa position in both age groups. The manifestations of class II hyperdivergent patients were mostly the opposite. In adults, except for the condylar long axis angle, the measurements of the condyle increased differently among skeletal patterns, while the measurements of the fossa decreased, as the joint spaces and fossa position remained approximately stable compared with those in adolescents.

CONCLUSION

The vertical skeletal pattern, rather than the class II sagittal skeletal pattern, may be the main factor affecting the morphology and position of the TMJ. Attention should be given to the TMJ area in hyperdivergent patients with a relatively poor-fit condyle-fossa relationship. The changes in the TMJ with age were mainly morphological rather than positional and varied with skeletal pattern.

BMP2 rs1005464 is associated with mandibular condyle size variation

This study aimed to evaluate the association between single nucleotide polymorphisms (SNPs) in endochondral development-related genes and mandibular condyle shape, size, volume, and symmetry traits. Cone-beam Computed Tomographies and genomic DNA from 118 individuals were evaluated (age range: 15-66 years). Data from twelve 3D landmarks on mandibular condyles were submitted to morphometric analyses including Procrustes fit, principal component analysis, and estimation of centroid sizes and fluctuating asymmetry scores. Condylar volumes were additionally measured. Seven SNPs across BMP2, BMP4, RUNX2 and SMAD6 were genotyped. Linear models were fit to evaluate the effect of the SNPs on the mandibular condyles' quantitative traits. Only the association between BMP2 rs1005464 and centroid size remained significant after adjusting to account for the false discovery rate due to multiple testing. Individuals carrying at least one A allele for this SNP showed larger condylar size than common homozygotes GG (β = 0.043; 95% CI: 0.014-0.071; P value = 0.028). The model including BMP2 rs1005464, age and sex of the participants explained 17% of the variation in condylar size. Shape, volume, and symmetry were not associated with the evaluated SNPs. These results suggest that BMP2 rs1005464 might be associated with variation in the mandibular condyles size.

A new classification of mandible defects and condyle changed after mandible reconstruction with FFF

Objectives

To explore a new classification of mandibular defects and changes in the preserved condyle after mandibular reconstruction with free fibular flap(FFF).

Study design

We reviewed patients who underwent mandibular reconstruction with FFF from 2015 to 2021 and classified the mandibular defects into five categories: classⅠ(unilateral-mandibular excluding condyle), classⅡ(unilateral-mandibular including condyle), classⅢ(bilateral-mandibular excluding condyle), classⅣ(bilateral-mandibular including one condyle), and classⅤ(bilateral-mandibular including both condyles). Cone Beam Computed Tomography (CBCT) data were collected preoperatively(T0), at 7-10 postoperative days(T1), 6 postoperative months(T2), and 1 postoperative year(T3). We calculated the condylar surface area, volume, and displacement.

Results

62 cases were collected. The condylar surface areas and volumes in T2 and T3 values were lower than those of T0 and T1(P < 0.01) The condylar displacement was the lowest in ClassI and the largest in ClassⅣ(P < 0.01), while no significant differences in classesⅠ-Ⅲ(P < 0.05). Displacement during T1-T0 was greater than that during T2-T0 and T3-T0(P < 0.05).

Conclusion

Mandibular reconstruction with FFF results in displacement and alteration of the condyle within a time interval, and this alteration stabilizes after 6 months. Mandibular defects that do not reach the midline, surgical alteration to preserve the condyle are not required. However, when the defects cross the midline, the condyle should be preserved as much as possible.

[Mandibular condyle localization in orthognathic surgery based on mandibular movement trajectory and its preliminary accuracy verification]

OBJECTIVE

To establish and assess the precision of pre-surgical condyle position planning using mandibular movement trajectory data for orthognathic surgery.

METHODS

Skull data from large-field cone beam computed tomography (CBCT) and dental oral scan data were imported into IVSPlan 1.0.25 software for 3D reconstruction and fusion, creating 3D models of the maxilla and mandible. Trajectory data of mandibular movement were collected using a mandibular motion recorder, and the data were integrated with the jaw models within the software. Subsequently, three-dimensional trajectories of the condyle were obtained through matrix transformations, rendering them visually accessible. A senior oral and maxillofacial surgeon with experience in both diagnosis and treatment of temporomandibular joint disease and orthognathic surgery selected the appropriate condyle position using the condyle movement trajectory interface. During surgical design, the mobile mandibular proximal segment was positioned accordingly. Routine orthognathic surgical planning was completed by determining the location of the mandibular distal segment, which was based on occlusal relationships with maxilla and facial aesthetics. A virtual mandible model was created by integrating data from the proximal and distal segment bone. Subsequently, a solid model was generated through rapid prototyping. The titanium plate was pre-shaped on the mandibular model, and the screw hole positions were determined to design a condylar positioning guide device. In accordance with the surgical plan, orthognathic surgery was performed, involving mandibular bilateral sagittal split ramus osteotomy (SSRO). The distal segment of the mandible was correctly aligned intermaxillary, while the proximal bone segment was positioned using the condylar positioning guide device and the pre-shaped titanium plate. The accuracy of this procedure was assessed in a study involving 10 patients with skeletal class Ⅱ malocclusion. Preoperative condyle location planning and intraoperative positioning were executed using the aforementioned techniques. CBCT data were collected both before the surgery and 2 weeks after the procedure, and the root mean square (RMS) distance between the preope-rative design position and the actual postoperative condyle position was analyzed.

RESULTS

The RMS of the condyle surface distance measured was (1.59±0.36) mm (95%CI: 1.35-1.70 mm). This value was found to be significantly less than 2 mm threshold recommended by the expert consensus (P < 0.05).

CONCLUSION

The mandibular trajectory may play a guiding role in determining the position of the mandibular proximal segment including the condyle in the orthognathic surgery. Through the use of a condylar positioning guide device and pre-shaped titanium plates, the condyle positioning can be personalized and customized with clinically acceptable accuracy.

The relationship between the oblique sagittal temporomandibular joint disc position and the volume surface area of the condyle in young TMD adults

The present study aims to compare the volume surface area of the condyle, the horizontal condylar axial angle and the disc-condyle angle between temporomandibular disorder (TMD) and asymptomatic volunteers, explore and analyze the relationship between the temporomandibular joint (TMJ) disc position in oblique sagittal plane and the volume surface area of the condyle in young adults with TMD symptoms. 84 young adult volunteers were received TMJ examination by Magnetic Resonance Imaging (MRI) and Cone Beam Computed Tomography (CBCT). TMD and asymptomatic volunteers were 42 each. MRI was used to assess the position of TMJ disc in the oblique sagittal plane with the condyle apex method. CBCT data were used for three-dimensional (3D) reconstruction of condyle and the measurements of the horizontal condylar axial angle and the volume surface area of the condyle. The condylar volume surface area of the TMD group was smaller than that of the asymptomatic group (p < 0.05), the disc condyle angle was larger than that of the asymptomatic group (p < 0.05), and no significant difference was found in the horizontal condylar axial angle (p > 0.05). In terms of correlation, the volume surface area of the condyle were negatively correlated with the position of the articular disc in TMD patients (p < 0.05). This significant negative correlation suggests that the possibility of disc displacement can be considered when poor condylar morphology is found.

Three-dimensional evaluation of the temporomandibular joints after unilateral surgically assisted rapid maxillary expansion in adults: A preliminary retrospective study

BACKGROUND

Unilateral surgically assisted rapid maxillary expansion (U-SARME) is a successful method for correction of true unilateral posterior crossbite (TUPC).

OBJECTIVES

This retrospective preliminary study aimed to evaluate the position and morphology of condyles in TUPC cases and the effects of U-SARME on condyle with the help of cone beam computed tomography (CBCT).

METHODS

Fifteen patients (mean age: 18.69 ± 1.59 years) who were diagnosed as TUPC and undergone U-SARME were selected. Preoperative (T0) and after 6-month retention (T1) DICOM data of CBCT images were evaluated with MIMICs version 19.0 software. Condylar morphology (medio-lateral and antero-posterior dimensions) and position (anterior, posterior, medial and lateral joint spaces, frontal/axial axis angles, the ratio of posterior to anterior joint space and the percentage of posterior to anterior joint space) were evaluated. Student's t-test was used for intergroup (crossbite, normal) comparisons. Paired-samples t-test was used for intra-group comparisons (p = .05).

RESULTS

There were no positional or dimensional asymmetry of the condyles between crossbite and normal sides initially and after expansion. Regarding T0-T1 changes, while significant increase was determined in medial (0.3 ± 0.29 mm; p = .001) and superior (0.39 ± 0.7 mm; p = .045) joint spaces on crossbite side, posterior (0.79 ± 0.99 mm; p = .008), superior (0.5 ± 0.79 mm; p = .029) and lateral joint spaces (0.31 ± 0.54 mm; p = .042) presented significant increases on normal side. However, no significant changes were found between crossbite and normal sides at T0 and T1.

CONCLUSIONS

Condyles were symmetrical in true unilateral posterior crossbite cases and the symmetry were not disrupted following U-SARME.

Appraisal of the Accuracy and Reliability of Cone-Beam Computed Tomography and Three-Dimensional Printing for Volumetric Mandibular Condyle Measurements of a Human Condyle

Background This study aims to evaluate the accuracy of volumetric measurements of three-dimensional (3D)-printed human condyles from cone-beam computed tomography (CBCT) in comparison to physical condyles using a water displacement test. Methodology A sample of 22 dry condyles was separated from the mandibular body by disc, mounted on a base made of casting wax, and scanned using the SCANORA (Scanora 3DX, Soredex, Finland) CBCT scanner. Subsequently, the projection data were reconstructed with the machine-dedicated OnDemand 3D (Cybermed Co., Seoul, Korea). The Standard Tessellation Language file was prepared for 3D printing using chitubox slicing software v1.9.1. Frozen water-washable gray resin was used for 3D printing. All condyles were printed using the same parameters and the same resin. The volumetric measurements were then performed using a customized modified pycnometer based on water volume and weight displacement. Volumetric measures were performed for both the physical human condyles and the 3D-printed replicas and the measurements were then compared. Results The volume of dry condyles using the water displacement method showed an average (±SD) of 1.925 ± 0.40 cm3. However, the volume of 3D-printed replicas using the water displacement method showed an average (±SD) of 2.109 ± 0.40 cm3. The differences in measurements were insignificant (p > 0.05), as revealed by an independent t-test. Conclusions Highly precise, accurate, and reliable CBCT for volumetric mandibular condyle was applied for measurements of a human condyle and 3D-printed replica. The modified pycnometer for volumetric measurements presented an excellent volumetric measure based on a simple water displacement device. The tested modified pycnometer can be applied in volumetric measurements in both 3D-printed and mandibular condyle. For best accuracy, the highest scanning resolution possible should be used. As it directly handles irregularly shaped solid objects in a non-destructive manner with a high level of precision and reliability, this 3D scanning approach may be seen as a superior alternative to the current measurement methods.

A Comparison of the Condyle and Articular Eminence in Asian Juvenile Idiopathic Osteoarthritis Patients with Unilateral and Bilateral TMJ Involvement: A Retrospective Case-Control Study

This study compared the condylar volume, length, and articular eminence (AE) characteristics of normal individuals to those with unilateral and bilateral juvenile idiopathic osteoarthritis (JOA). The 116 patients were divided into four groups: Control (n = 16), affected condyle of unilateral JOA (Aff-Uni) (n = 36), non-affected condyle of JOA (NonAff-uni) (n = 36), and bilateral JOA (Bilateral) (n = 28). The differences in condyle volume and length and AE were analyzed using ANOVA and Bonferroni post-hoc tests. The results showed that Bilateral had a significantly different condylar volume, especially in the condylar head (p < 0.01), specifically the middle, anterior, and medial parts (p < 0.05). Condylar length also differed among the groups, with differences observed between the control group and the other three groups, as well as between the bilateral group and the other three groups (p < 0.01). AE total volume differed between the control group and Aff-Uni. In the detailed comparison, Aff-Uni and NonAff-Uni were smaller than the control group in the posterior, lateral, and medial sections (p < 0.05). In conclusion, depending on the involvement of unilateral or bilateral JOA, there were differences in condylar volume and AE when compared to the normal control group. Therefore, a prognosis should be evaluated by distinguishing between patients with unilateral and bilateral JOA.

Impact of molar teeth distalization by clear aligners on temporomandibular joint: a three-dimensional study

BACKGROUND

Maxillary molar distalization is a common technique used in the non-extraction treatment of Angle Class II malocclusion that can effectively correct the molar relationship and create spaces for anterior teeth alignment. However, this approach may also impact the temporomandibular joint (TMJ) due to predictable changes in the posterior vertical dimension. Despite its widespread use, Class II malocclusions correction by molar distalization with clear aligners has not been investigated for their effects on the TMJ. Therefore, this study aimed to analyze the impact of sequential molar distalization using clear aligners on the TMJ.

METHODS

Three-dimensional CBCT scans of 23 non-growing patients (7 males, 16 females; mean age 29.8 ± 4.6 years) with skeletal class I or II malocclusion and a bilateral molar class II relationship treated by sequential upper molars distalization with orthodontic clear aligners (Invisalign, Align Technology, San Josè, Ca, USA). A total of 46 joints were examined before and after molar distalization using Anatomage InvivoDental 6.0.3. Linear and angular measurements of the mandibular joint were measured, including joint parameters, inclination, position, and the dimension of the condyle and articular fossa. In addition, 3D volumetric spaces of the joint were analyzed. All data were statistically analyzed by paired T test to determine the differences between the pre-and post-orthodontic procedures.

RESULTS

No statistically significant differences were found in all primary effects resulting from maxillary molars distalization by clear aligners on TMJ components measurements and joint spaces between T0 and T1. Meanwhile, statistically significant differences were observed in the linear position of the upper molars and the molar relationship parameter with at least P ≤ 0.05.

CONCLUSION

Treatment by sequential upper molars distalization with clear aligners does not lead to significant TMJ parameters changes in condyle and fossa spaces, dimensions, and positions.

Tridimensional assessment of the mandibular angle in patients with different skeletal patterns by cone-beam computed tomography scans: a retrospective study

BACKGROUND

Since the muscles of chewing are involved in the region of the mandibular angle, important structures in surgical and orthodontic procedures, to study its morphological aspects and the possible influence of different patterns of skeletal development would be of interest. Thus, this study aimed to assess the influence of patient characteristics - such as sex, skeletal malocclusion (Class I, Class II, and Class III) and facial type (brachycephalic, mesocephalic, and dolichocephalic) - on the width, height, thickness, and volume of the mandibular angle, using cone-beam computed tomography (CBCT) scans.

METHODS

CBCT scans were assessed - 144 men and 154 women, total of 298 - and classified according to skeletal patterns (skeletal malocclusions and facial types). Width, height, and thickness of the mandibular angle were measured using OnDemand 3D software. The volumetric measures of the mandibular angle were obtained using the ITK-SNAP software. Analysis of Variance (multiway ANOVA) with Tukey's post-hoc test compared the data, with a 5% significance level.

RESULTS

Among the factors studied, sex significantly influenced all the analyzed variables (height, width, thickness, and volume of the mandibular angle) (p < 0.05); in general, male individuals presented higher values than females. In some cases, the skeletal malocclusion and facial type factors influenced only the width and height variables (p < 0.05); in general, the Class III and dolichocephalic individuals presented higher values in relation to the other types of skeletal malocclusions and facial types.

CONCLUSIONS

Variations in the craniofacial growth pattern, considering the different skeletal malocclusions and facial types, had some influence in the width and height dimensions of the mandibular angle. Furthermore, sex influenced all the studied variables.

Three-dimensional evaluation of mandibular condyle and coronoid process according to sex, age, and skeletal deformities

OBJECTIVE

To correlate the volume of the mandibular condyle (MC) and the coronoid process (CP) with sex, age, and skeletal deformities.

METHODS

The structures were visualized through semi-automatic segmentation of the 3D model and complemented with manual segmentation, using the ITK-SNAP 3.0 software. Mann-Whitney, Kruskal-Wallis, and the Dunn test were performed (p < 0.05).

RESULTS

The MC volume showed statistical differences between sex and skeletal deformities. Men and Class III patients showed higher values. CP volume was not influenced by age or skeletal deformities. However, statistical differences were found between sex, with higher values for men.

CONCLUSION

MC volume was influenced by sex and skeletal deformities, while CP was influenced only by sex. Women have smaller volumes for these structures. Age is not correlated with the volume of MC and CP. The highest and lowest values of condylar volume were found for Class III and II individuals, respectively.

Relationship between the condyle morphology and clinical findings in terms of gender, age, and remaining teeth on cone beam computed tomography images

Aim: This study aimed to evaluate the relationship between clinical findings and some factors such as age, gender, and remaining teeth on the anatomy of the temporomandibular joint in order to diagnose normal variations from abnormal cases. Methods: In this cross-sectional study, cone-beam computed tomography (CBCT) images of 144 patients referring to Tabriz Dental School for various reasons were selected and evaluated. The different aspects of the clinical parameters and the morphology of the condyle were evaluated on coronal, axial, and sagittal views. The CBCT prepared using the axial cross-sections had been 0.5 mm in thickness. The sagittal cross-sections had been evaluated perpendicular to the lengthy axis of the condyle at a thickness of 1 mm and the coronal cross-sections had been evaluated parallel to the lengthy axis of the condyle at a thickness of 1 mm. Data were analyzed with descriptive statistical methods and t-test, chi-squared test, using SPSS 20. The significance level of the study was p < 0.05. Results: There was a significant relationship between the condyle morphology, number of the teeth, and mastication side (p = 0.040). There were significant relationships between the condyle morphology, age between 20-40, and occlusion class I on the all the three views (coronal, axial, sagittal) (p = 0.04), (p = 0.006), (p = 0.006). Also, significant relationships were found in the condyle morphology and location of pain according to age, the number of remaining teeth, and gender. (p = 0.046) (p = 0.027) (p = 0.035). Conclusion: There are significant relationships between the clinical symptoms and condyle morphology based on age, gender, and the number of remaining teeth. The clinical finding that has the most significant relationship between the condyle morphology, remaining teeth (9-16 teeth), all of the age range (20-80 year), and gender was mastication side.

Analysis of the Volumetric Asymmetry of the Mandibular Condyles Using CBCT

Objectives

The aim of this study was to analyse volumetric asymmetries between the right and left condyles in relation to age, gender, and dental status.

Materials and methods

A retrospective analysis of 150 cone beam computed tomography (CBCT) scans was conducted. A single investigator performed the volumetric analysis of the CBCT scans using Vesalius 3D software. The volumetric data were analysed in relation to the gender, age, and dental status.

Results

The mean right condylar volume was significantly higher (P < .01) than the left condylar volume. Right and left condylar volumes were significantly higher (P < .01) in male study participants when compared to female study participants. There was no significant difference (P = .47) in the volumetric asymmetry between the male and female study participants. The volumetric asymmetry was significantly higher (P < .01) in the older age groups when compared to the younger age groups. The volumetric asymmetry was significantly higher (P < .01) in the partially and completely edentulous patients when compared to the dentate study participants. The condylar volume on the side having a partially edentulous area was significantly lower than the condylar volume of the contralateral dentate side (P < .001).

Conclusions

The volumetric asymmetry between the right and left condyle significantly increases with age and edentulousness. The result of the study encourages the clinicians to perform volumetric evaluation of the condyles in cases of radiographically evident condylar asymmetries to obtain a more accurate diagnosis.

Advantages of deep learning with convolutional neural network in detecting disc displacement of the temporomandibular joint in magnetic resonance imaging

This study investigated the usefulness of deep learning-based automatic detection of anterior disc displacement (ADD) from magnetic resonance imaging (MRI) of patients with temporomandibular joint disorder (TMD). Sagittal MRI images of 2520 TMJs were collected from 861 men and 399 women (average age 37.33 ± 18.83 years). A deep learning algorithm with a convolutional neural network was developed. Data augmentation and the Adam optimizer were applied to reduce the risk of overfitting the deep-learning model. The prediction performances were compared between the models and human experts based on areas under the curve (AUCs). The fine-tuning model showed excellent prediction performance (AUC = 0.8775) and acceptable accuracy (approximately 77%). Comparing the AUC values of the from-scratch (0.8269) and freeze models (0.5858) showed lower performances of the other models compared to the fine-tuning model. In Grad-CAM visualizations, the fine-tuning scheme focused more on the TMJ disc when judging ADD, and the sparsity was higher than that of the from-scratch scheme (84.69% vs. 55.61%, p < 0.05). The three fine-tuned ensemble models using different data augmentation techniques showed a prediction accuracy of 83%. Moreover, the AUC values of ADD were higher when patients with TMD were divided by age (0.8549–0.9275) and sex (male: 0.8483, female: 0.9276). While the accuracy of the ensemble model was higher than that of human experts, the difference was not significant (p = 0.1987–0.0671). Learning from pre-trained weights allowed the fine-tuning model to outperform the from-scratch model. Another benefit of the fine-tuning model for diagnosing ADD of TMJ in Grad-CAM analysis was the deactivation of unwanted gradient values to provide clearer visualizations compared to the from-scratch model. The Grad-CAM visualizations also agreed with the model learned through important features in the joint disc area. The accuracy was further improved by an ensemble of three fine-tuning models using diversified data. The main benefits of this model were the higher specificity compared to human experts, which may be useful for preventing true negative cases, and the maintenance of its prediction accuracy across sexes and ages, suggesting a generalized prediction.

Three-Dimensional Assessment of the Temporomandibular Joint Changes Following Reversed Twin Block Therapy of Patients With Skeletal Class III Malocclusion in Conjunction With the Photobiomodulation Therapy: A Randomized Controlled Clinical Trial

Background: Despite the positive effect of the photobiomodulation therapy (PBMT) application on animals, the primary role of this technique on the human condyle is still unclear. Several experimental reports have shown the efficacy of PBMT in inducing cellular changes in the temporomandibular joint (TMJ) region during functional treatment of patients with skeletal deformities. Still, the lack of information about its effects on human condyles requires further studies.

Objectives: This study aimed to evaluate the effect of PBMT on the TMJ components following Class III treatment with the reversed twin block (RTB) appliance in growing patients. 

Materials and Method: Forty children (12 females, 28 males) between the age of nine and eleven years with skeletal Class III were assigned randomly to the RTB group with photobiomodulation (RTB+PBMT) or the control group (RTB). The PBMT was applied to the TMJ region using an 808-nm wavelength Ga-Al-As semiconductor laser device with 5 Joules/cm² energydensity on days 1, 3, 7, and 14 of the first month. Afterwards, the irradiation was conducted every 15 days until the end of the treatment. Cone-beam computerized tomography (CBCT) images were taken before (T1) treatment and following the end of treatment (T2) to assess TMJ and skeletal changes.

Results: Condylar volume was significantly increased in the RTB group only by a mean of 287.97 mm³ (p<0.001). The significantly backward and upward condylar movement was observed in the RTB and RTB+PBMT groups (superior joint space (SJS): 0.26 mm, 0.15 mm; posterior joint space (PJS): 0.42mm, 0.11mm, respectively). The RTB group showed the most remarkable changes. Significant improvement of the sagittal maxilla-mandibular relationship was greater in the RTB+PBMT group compared to the RTB group (p=0.02).

Conclusion: There were no considerable differences in the condylar position after Class III treatment between the RTB and the RTB+PBMT groups. But a difference in the condylar volume was noticed between the two group.

Oval Type of Human Mandibular Condyle in Panoramic Radiographs of a Tertiary Care Centre: A Descriptive Cross-sectional Study

Introduction

Mandibular condyle is a prominent structure in the mandible, which forms the temporomandibular joint. An oval-shaped condyle is considered to be present with a normal temporomandibular joint and any morphological variation of the condyle is assumed to be pathologic in temporomandibular disorders. The aim of the study was to find out the prevalence of oval shaped mandibular condyle among orthopantomogram radiographs of patients visiting the tertiary care centre.

Methods

A descriptive cross-sectional study was performed among 752 condyles visiting a tertiary care center from November 29, 2021 to April 1, 2022. The ethical approval was taken from the Institutional Review Committee (Reference number: 184 (6-11) 078/079) before conducting the study. Convenience sampling was done. The radiographs were first examined and the observed morphological type of mandibular condyle was noted. Data analysis was done using Statistical Package for the Social Sciences version 22.0. Point estimate at 95% Confidence Interval was calculated along with frequency and proportion for binary data.

Results

The prevalence of oval shaped mandibular condyles out of 752 condyles was 416 (55.32%) (51.77-58.87 at 95% Confidence Interval). The oval-shaped condyle on the right side was 205 (54.52%) and on the left side was 211 (56.12%).

Conclusions

The prevalence of oval shaped condyles among patients in this study was similar to the studies done in similar settings.

Keywords

condyle; mandible; Nepal; X-ray.

Comprehensive three-dimensional positional and morphological assessment of the temporomandibular joint in skeletal Class II patients with mandibular retrognathism in different vertical skeletal patterns

Background

Only a few studies have used 3D cone-beam computed tomography (CBCT) analysis to evaluate the positional and morphological characteristics of the temporomandibular joint (TMJ) in adults with skeletal Class II. No studies have focused on the case of skeletal Class II with mandibular retrognathism in different vertical skeletal patterns. As a result, this study aimed to evaluate and compare the position and morphology of TMJ in adults with skeletal Class II with mandibular retrognathism in different vertical skeletal patterns to the position and morphology of TMJ in the normal Chinese adult population in three dimensions.

Methods

This retrospective study analyzed CBCT images of 80 adult patients. Subjects with skeletal Class II with a normal sagittal position of the maxilla and mandibular retrognathism were classified according to the mandibular angle and facial height ratio into three groups of 20 subjects each: hypodivergent, normodivergent, and hyperdivergent groups, as well as a control group of 20 subjects. The following 3D measurements of TMJ were evaluated: (1) position, parameters, and inclination of the mandibular fossa; (2) position, parameters, and inclination of the mandibular condyle; (3) condyle centralization in their respective mandibular fossae; (4) anterior, posterior, superior, and medial joint spaces; and (5) 3D volumetric measurements of the TMJ spaces. Measurements were statistically analyzed by one-way ANOVA test, followed by Tukey’s post hoc test.

Results

Significant differences were found in the hyperdivergent and hypodivergent groups compared with the normal group in the vertical and anteroposterior mandibular fossa position, vertical condylar inclination, and condylar width and length. The hyperdivergent group showed the significantly highest condylar inclination with the midsagittal plane; anterior and superior positioning of the condyle; smallest anterior, superior, and medial joint spaces; and largest volumetric total joint space relative to the two other groups.

Conclusions

The condyle-fossa position and morphology differ with various vertical facial patterns in individuals with skeletal Class II mandibular retrognathism. These differences could be considered during TMD diagnosis and orthodontic treatment.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12903-022-02174-6.

Volumetric analysis of normal condyles and those with disc displacement with reduction in the Indonesian population: A CBCT study

Purpose

Disc displacement can cause resorption of the head of the condyle and affect its volume. This study analysed the volume of normal condyles and those with disc displacement with reduction (DDR) in cone-beam computed tomography (CBCT) scans from the Indonesian population.

Materials and Methods

This study analysed 56 condyles (26 normal and 30 with DDR) from patients who visited the Oral and Maxillofacial Radiology Unit after being referred from the Prosthodontics Unit at Dental Hospital Universitas Padjadjaran from December 2020 to February 2021. Samples were divided into 2 groups (normal and DDR left and right-side condyles) based on the DC/TMD Axis 1 form through the clinical examination results. Both sample groups were exposed to CBCT radiation. The CBCT imaging results in the Digital Imaging and Communications in Medicine format were exported to the open-source ITK-SNAP format to determine condyle volume. Volumetric data from the cortical and trabecular areas of the right or left side condyles were arranged by sex. The independent t-test was used to determine the significance of differences with IBM SPSS version 21.0. Intra- and inter-observer reliability and validity were tested before determining the volume of the condyles.

Results

Normal condyles and DDR condyles showed significant differences in volume (P<0.05). Significant differences were also seen in cortical (P=0.0007) and trabecular (P=0.0045) volumes. There was a significant difference in condylar volume based on sex.

Conclusion

The normal condyle volume was significantly different from the DDR condyle volume in both sexes.

The relationship between the size of temporomandibular joint condyle and the sagittal disc-condyle position in adults

OBJECTIVE

To explore the relationship between the size of temporomandibular joint (TMJ) condyle and the sagittal disc-condyle position and the relationship between the condylar size and craniofacial structure.

METHODS

Seventy-four subjects (23.82 ± 3.77 years) underwent cone beam computed tomography (CBCT) and lateral cephalograms for orthodontics and volunteered to undergo magnetic resonance imaging (MRI). Mimics was used to calculate the volume and surface area of the condyle. MRI was used to evaluate the sagittal disc-condyle position. The lateral cephalograms were analyzed by Jarabak analysis.

RESULTS

The condylar volume and surface area were negatively correlated with the sagittal disc-condyle position. The condylar volume and surface area were positively correlated with Ar-Go, S-Go, and S-Go/N-Me*100% (p < 0.05) and negatively correlated with ∠Ar-Go-Me and ∠N-Go-Me (p < 0.05).

CONCLUSION

Condylar size was negatively correlated with the sagittal disc-condyle position. The condylar size was correlated with the vertical skeletal pattern.

Volumetric and Morphological Analysis of Mandibular Condyles of Angle Class 2 and 3 Malocclusion Patients

ABSTRACT

This study was conducted to provide diametric and volumetric data of mandibular condyles from patients with Angle class 2 and 3 malocclusions by semiautomatic segmentation based upon cone-beam computed tomography.Cone-beam computed tomography images of 79 patients were analyzed. By using the open-source software "ITK-SNAP", diametric and volumetric measurements of 158 mandibular condyles were performed. Descriptive statistics were calculated for all normally distributed variables. Correlations between patients with Angle class 2 and 3 were calculated with the independent Student t test. P values P < 0.05 were considered significant.Irrespective of the side, patients with class 2 malocclusion showed smaller mandibular condyles (right: 1.128 ± 0.504 cm3; left: 1.222 ± 0.596 cm3) than patients with class 3 (right: 1.504 ± 0.361 cm3; left: 1.493 ± 0.335 cm3). These results were reproducible also in accordance with the diametric measurement (class 2 right: 16.75 ± 2.72 mm; left: 17.04 ± 3.01 mm) (class 3 right: 18.24 ± 2.54 mm; left: 18.32 ± 2.13 mm). However, volumetric differences were highly statistically significant (right: P = 0.001; left: P = 0.018) while diametric differences were slightly significant for the right and not significant for the left side (right: P = 0.042; left: P = 0.053).Diametric and volumetric analyses offer important additional information based on 3D images of cone-beam computed tomography technology. Significant differences in diameter and volume of mandibular condyles could be assessed between different classes of malocclusion.

A volumetric study of mandibular condyles in orthognathic patients by semiautomatic segmentation

Purpose

This study was conducted to elucidate volumetric data of mandibular condyles of orthognathic patients by analyzing cone beam computed tomography images based upon semiautomatic segmentation.

Methods

Cone beam computed tomography images of 87 patients with malocclusions were analyzed in this retrospective study. Patients were between 17 and 53 years old and diagnosed with Angle class I, II, or III malocclusion. By using the validated open-source software “ITK-SNAP,” the volumetric measurements of 174 mandibular condyles were performed. Volumetric analysis was performed according to intra-subject side differences by paired Student t test. In accordance to inter-subject side, gender, age and type of malocclusion differences bivariate analysis and ANOVA were applied.

Results

The mean volume for the right condyle was 1.378 ± 0.447 cm³, with a maximum of 2.379 cm³ and a minimum of 0.121 cm³. The mean volume for the left side was 1.435 ± 0.474 cm³, with a maximum of 3.264 cm³ and a minimum of 0.109 cm³. Bivariate analysis indicated a highly significant inter-subject difference between the volume of the left and right mandibular condyles (p < 0.01). Females had a significantly smaller condyle volume than males (p < 0.05 left condyle; p < 0.01 right condyle).

Conclusion

The fact that shape and volume of mandibular condyles show a high susceptibility to pathological alterations and particularly malocclusions makes a precise knowledge about volumetric changes indispensable. Our results show that significant inter-subject differences in condyle volume could be found with respect to the side and gender. Larger volumes could be assessed for the left condyle and for male patients.

Morphological Assessment of TMJ Spaces, Mandibular Condyle, and Glenoid Fossa Using Cone Beam Computed Tomography (CBCT): A Retrospective Analysis

Background  The temporomandibular joint (TMJ) is included in the category of ginglymoarthrodial synovial joints. The mandibular condyle plays a vital part in the development of the craniofacial complex. Hence, the evaluation and assessment of the condylar volume and its morphology are of utmost importance.

Aim  The aim of this research was to use cone beam computed tomography (CBCT) imaging modality to evaluate the morphology of the mandibular condyle and glenoid fossa in a selected population and document any morphometric changes.

Setting and Design  It is an observational study.

Materials and Methods  A retrospective CBCT analysis was performed on 119 patients. The length, width, height, linear measurements of the joint spaces (anterior, posterior, and superior), volume of the condyle, and roof of glenoid fossa thickness were evaluated on both the left and right sides in both males and females.

Results  The height, width, and length of mandibular condyle were significantly increased in males on both sides. Except for the left anterior space, all other spaces were significantly larger in males. Overall, the volume of the condyles in males was significantly increased on both sides.

Conclusion  CBCT can be a valuable diagnostic aid in the evaluation of various dimensions, joint spaces, and condylar volume in different planes and thus, can be a useful predictor in the assessment of treatment outcomes of disorders affecting the TMJ.

New Method for Analysis of the Temporomandibular Joint Using Cone Beam Computed Tomography

Modern dentistry commonly uses a variety of imaging methods to support diagnosis and treatment. Among them, cone beam computed tomography (CBCT) is particularly useful in presenting head structures, such as the temporomandibular joint (TMJ). The determination of the morphology of the joint is an important part of the diagnosis as well as the monitoring of the treatment results. It can be accomplished by measurement of the TMJ gap width at three selected places, taken at a specific cross-section. This study presents a new approach to these measurements. First, the CBCT images are denoised using curvilinear methods, and the volume of interest is determined. Then, the orientation of the vertical cross-section plane is computed based on segmented axial sections of the TMJ head. Finally, the cross-section plane is used to determine the standardized locations, at which the width of the gap between condyle and fossa is measured. The elaborated method was tested on selected TMJ CBCT scans with satisfactory results. The proposed solution lays the basis for the development of an autonomous method of TMJ index identification.

Differences in mandibular condyle and glenoid fossa morphology in relation to vertical and sagittal skeletal patterns: A cone-beam computed tomography study

Objective

This study aimed to evaluate the following null hypothesis: there are no differences in the morphology of the temporomandibular joint (TMJ) structures in relation to vertical and sagittal cephalometric patterns.

Methods

This retrospective study was performed with 131 participants showing no TMJ symptoms. The participants were divided into Class I, II, and III groups on the basis of their sagittal cephalometric relationships and into hyperdivergent, normodivergent, and hypodivergent groups on the basis of their vertical cephalometric relationships. The following measurements were performed using cone-beam computed tomography images and compared among the groups: condylar volume, condylar size (width, length, and height), fossa size (length and height), and condyle-to-fossa joint spaces at the anterior, superior, and posterior condylar poles.

Results

The null hypothesis was rejected. The Class III group showed larger values for condylar width, condylar height, and fossa height than the Class II group (p < 0.05). Condylar volume and superior joint space in the hyperdivergent group were significantly smaller than those in the other two vertical groups (p < 0.001), whereas fossa length and height were significantly larger in the hyperdivergent group than in the other groups (p < 0.01). The hypodivergent group showed a greater condylar width than the hyperdivergent group (p < 0.01). The sagittal and vertical cephalometric patterns showed statistically significant interactions for fossa length and height.

Conclusions

TMJ morphology differed across diverse skeletal cephalometric patterns. The fossa length and height were affected by the interactions of the vertical and sagittal skeletal patterns.

Three-dimensional morphological and positional analysis of the temporomandibular joint in adults with posterior crossbite: A cross-sectional comparative study

OBJECTIVES

The purpose of this study was to three-dimensionally (3D) evaluate the morphological and positional features of the temporomandibular joint (TMJ) in adults with unilateral and bilateral posterior crossbite compared with aligned control subjects.

MATERIALS AND METHODS

This cross-sectional comparative study analysed cone beam computed tomography (CBCT) images of 90 adult subjects' divided into three equal groups: bilateral posterior crossbite (BCG), unilateral posterior crossbite (UCG) and control group (CG). 3D measurements of the TMJ included the following: (a) position, angulation and inclination of the mandibular condyles; (b) centralisation of the condyles in their respective mandibular fossae; and (c) volumetric measurements of the TMJ spaces. Intra- and intergroup differences were identified using the paired Student's t test and an analysis of variance (ANOVA) followed by Tukey's post hoc test, respectively.

RESULTS

Regarding the intra-group side-based comparisons, there were significant differences in the anterior and superior joint spaces and the anteroposterior condylar joint position in the UCG. Intergroup comparisons revealed significant differences in the vertical condylar inclination, medial condylar position, condylar width and height, and volumetric joint space between the unaffected side of the UCG and left sides of the other groups. There were significant differences in the anteroposterior condylar inclination, medial condylar position, condylar width and height, anterior, posterior, superior and volumetric joint spaces, and anteroposterior condylar joint position between the crossbite side of the UCG and the right sides of the other groups.

CONCLUSION

Skeletal crossbite accompanied with characteristic morphological and positional TMJ features associated with unilateral posterior crossbite and are associated with side-specific TMJ asymmetry.

Comprehensive 3D analysis of condylar morphology in adults with different skeletal patterns - a cross-sectional study

Background

The correlation between individuals’ condylar morphology and their skeletal pattern is of great interest for treatment strategies ranging from orthodontic orthopaedics to orthognathic surgery. The objective of the present study was to investigate this relationship three-dimensionally.

Methods

A total of 111 adult patients (mean age = 27.0 ± 10.2 years) who underwent head computed tomography or cone beam computed tomography scans were included. Based on these data, 3D models of the skull and the condyles were calculated. The craniofacial skeleton was evaluated (1) transversally regarding skeletal symmetry (menton deviation), (2) sagittally regarding skeletal classes (Wits appraisal) and vertically regarding the inclination of the jaws (maxillomandibular plane angle). The condylar morphology was assessed (a) linearly by the condylar width, height and depth; (b) angularly by the antero-posterior and medio-lateral condylar inclination; and (c) volumetrically by the ratio of the condylar volume/mandibular volume (C/Mand).

Results

(1) Transversal: Asymmetric patients showed significantly higher discrepancies in the volumetric ratio C/Mand on the deviation and non-deviation side compared to symmetric patients. (2) Sagittal: Class III subjects demonstrated longer, more voluminous condyles with higher antero-posterior and medio-lateral inclination angles compared to Class II participants. (3) Vertical: Hyperdivergent subjects had smaller condyles with higher antero-posterior inclination angles than those of hypodivergent subjects. No interactions of skeletal class and vertical relationships regarding condylar morphology were observed.

Conclusions

This study demonstrates a clear correlation between pronounced skeletal patterns and condylar morphology in an adult population. The description of radiographic condyle characteristics in relation to the craniofacial morphology improves orthodontic treatment planning and could be helpful in the diagnosis of temporomandibular joint pathologies.

Bone Changes in the Condylar Process of the Mandible in Computed Tomography Images and Cephalogram in a Female Patient during a Growth Spurt Treated with a Removable Functional Appliance

Introduction

Functional treatment is the type of treatment preferred in young patients with lateral bite because it leads to simultaneous improvement of occlusion and facial profile.

Objective

The aim of this study is to assess bone changes within the condylar process of the mandible and to associate them with the changes observed in the analysis of lateral cephalograms and in the patient's occlusion.

Materials and Methods

Cone beam tomography of the temporomandibular joint, lateral radiogram of the skull, was performed at the beginning of treatment and after one year of therapy. Changes in cephalometric radiograms were evaluated by analyzing them and shown by making superimposition and staining layers. For the purpose of assessing bone changes within the condylar process, digital 3D solids of these processes were generated using data from computed tomography.

Results

Correction towards Angle's dental class I, overjet reduction from 8 mm to 3 mm, and improvement of the patient's profile were obtained. A rotation of the occlusal plane and improvement in an ANB by 1° and in the WITS measurement by 2.7 mm were observed. A growth of the condylar processes "backwards" and "upwards" was also observed, as well as a change of their shape and volume.

Conclusions

The obtained results suggest that the patient's significant improvement in occlusal conditions is due to posterior growth stimulation of the condylar processes of the mandible. The results confirm the validity of using this treatment technique in the case of growing children with complete posterior occlusion.

Three-Dimensional Assessment of Mandibular Condylar Volume and Position Subsequent to Twin Block Functional Therapy of Skeletal Class II Malocclusion Accompanied by Low-Level Laser Therapy

This study aimed to evaluate and compare the effect of low-level laser therapy (LLLT) on mandibular condylar volume and position following treatment of a Class II malocclusion with a twin block (TB) appliance employing cone beam computed tomography (CBCT). Twenty-four growing patients, aged 9–12 years, were randomly allocated into control and laser groups. All patients were treated with a TB appliance. The patients in the laser group were treated weekly with a gallium–aluminum–arsenide (GaAlAs) diode laser around the temporomandibular joint (TMJ) region for three months. CBCT images were obtained before and after TB therapy and the changes in TMJ and skeletal variables were evaluated and compared among and between the groups. In the laser group, the condylar volume of the right and left sides significantly increased by 213.3 mm³ and 231.2 mm³, respectively (p < 0.05), whereas in the control group it significantly increased by 225.2 mm³, and 244.2 mm³, respectively (p < 0.05), with forward and lateral positioning of both sides. Furthermore, effective mandibular, ramus, and corpus lengths were increased, which were not significant between the groups. Low-Level Laser therapy accomplished no considerable effect on mandibular condylar volume and position following the functional orthopedic treatment of skeletal Class II malocclusions using a TB appliance.

Effect of multiple injections of botulinum toxin into painful masticatory muscles on bone density in the temporomandibular complex

Background

Adverse effects of masticatory muscle injections of Botulinum Toxin (Btx) have been noted in animal and, less dramatically, human studies.

Objective

Among women treated in multiple community‐based private practices, to compare TMJ bone density and mandibular condylar volume between patients with myofascial TMJD receiving multiple masticatory muscle Btx treatments and similarly diagnosed women not receiving such treatment.

Methods

Cohorts consisted of women whose treatment charts indicated a diagnosis of myofascial TMJD: 35 received at least 2 Btx treatment cycles; 44 received none. Bone density at pre‐specified regions of interest (ROI) was defined by grey scale values from Cone Beam CT, adjusting for a fixed density phantom included in each scan. Mean bone density and mandibular condyle volume were compared between groups. Dose‐response effects were tested within the Btx‐exposed group.

Results

The mean density of primary and secondary ROIs was similar between exposure groups, as was condylar volume. Among Btx‐exposed women, increasing dose of Btx to the temporalis muscle was inversely proportional to the density of the trabecular area of the mandible body. Many Btx‐exposed women received smaller doses of Btx to the masseter muscles than in most TMJD Btx clinical trials.

Conclusion

Masticatory muscle injections of Btx failed to produce clinically significant TMJ bone‐related changes. Should Btx receive regulatory approval for treatment of myofascial TMJD, a phase IV study is recommended to evaluate potential adverse effects of Btx on bone and muscle when administered at higher doses and/or for more treatment cycles.

Volumetric and morphological analysis of condyle and glenoid fossa on computed tomography

AIM

The aim of this study was to evaluate temporomandibular joint (TMJ) condyle and glenoid fossa morphology with measurements on Computed Tomography (CT) and volumetric analysis using InVesalius software program.

MATERIALS AND METHODS

250 condyles in 125 patients (mean age: 40.64) was evaluated on CT. Length, width, and height of the condyle, condylar volume, the thickness of glenoid fossa (TGF), condyle surface area, anterior space (AS), superior space (SS), and posterior space (PS) were measured in this study. Two left and right sides of the jaw have been measured. Linear measurements were performed with the image analysis program (Image J, 1.4 v version, National Institutes of Health, Bethesda, MD). Volume and surface area measurements were performed with InVesalius software (CTI, Campinas, SãoPaulo, Brazil).

RESULTS

To compare the dimensions of the condyle between males and females, there was only a significant difference in left AS and SS and no significant difference was found between males and females in other measured factors. There was a significant difference between the age groups and left SS. A significant difference was also found between the age groups and condylar height, condyle surface area, and condylar volume on both right and left sides.

CONCLUSION

Evaluation of condylar morphology is important to assess the TMJ anomalies and bony changes. This study showed no significant differences between gender and all measured factors except in the left AS and SS. However, age factor had a major effect on the morphology.

Reliability and accuracy of a method for measuring temporomandibular joint condylar volume

OBJECTIVE

The aim of this study was to develop and validate a technique for mandibular condyle segmentation and volume determination by using cone beam computed tomography (CBCT).

STUDY DESIGN

A dry skull was used to generate 3 dimensional (3-D)-printed mandible models that were then imaged by using CBCT. Semiautomatic segmentation of condyles was completed. The Frankfurt plane was established and translated to the most inferior point of the sigmoid notch, and the condylar volume superior to the plane was determined. This procedure was repeated on 3-D-printed mandibles by using physical landmarks and the water displacement method to obtain the physical volume. This was repeated 3 times to evaluate reliability. Sensitivity analysis was performed to demonstrate the effect of discrepancies in locating landmarks in the Frankfurt plane. Condylar volume measurements obtained from CBCT were compared with physical measurements through repeated-measures analysis of variance (ANOVA) to determine accuracy.

RESULTS

Condylar volume obtained from CBCT and physical measurements resulted in an intraclass correlation coefficient of 0.988 (0.918, 0.998) (P < .01) with both modalities, demonstrating excellent intrarater reliability. The mean difference of volume measurements between the modalities was not statistically significant (P = .365). Potential discrepancies in porion coordinates had minimal impact on condylar volume change.

CONCLUSIONS

The condylar segmentation technique proved to be a reliable and accurate method for evaluating condylar volume.

Evaluation of Imaging Software Accuracy for 3-Dimensional Analysis of the Mandibular Condyle. A Comparative Study Using a Surface-to-Surface Matching Technique

The aim of this study was to assess the accuracy of 3D rendering of the mandibular condylar region obtained from different semi-automatic segmentation methodology. A total of 10 Cone beam computed tomography (CBCT) were selected to perform semi-automatic segmentation of the condyles by using three free-source software (Invesalius, version 3.0.0, Centro de Tecnologia da Informação Renato Archer, Campinas, SP, Brazil; ITK-Snap, version2.2.0; Slicer 3D, version 4.10.2) and one commercially available software Dolphin 3D (Dolphin Imaging, version 11.0, Chatsworth, CA, USA). The same models were also manually segmented (Mimics, version 17.01, Materialise, Leuven, Belgium) and set as ground truth. The accuracy of semi-automatic segmentation was evaluated by (1) comparing the volume of each semi-automatic 3D rendered condylar model with that obtained with manual segmentation, (2) deviation analysis of each 3D rendered mandibular models with those obtained from manual segmentation. No significant differences were found in the volumetric dimensions of the condylar models among the tested software (p > 0.05). However, the color-coded map showed underestimation of the condylar models obtained with ITK-Snap and Slicer 3D, and overestimation with Dolphin 3D and Invesalius. Excellent reliability was found for both intra-observer and inter-observer readings. Despite the excellent reliability, the present findings suggest that data of condylar morphology obtained with semi-automatic segmentation should be taken with caution when an accurate definition of condylar boundaries is required.

Association between condylar position changes and functional outcomes after condylar reconstruction by free fibular flap

OBJECTIVES

Stable and appropriate condyle positioning is necessary for maintaining temporomandibular joint function. It is unclear if this position remains stable in patients after free fibular flap (FFF) condylar reconstruction. We investigated whether condylar position deviated after reconstruction, and whether this affected functional recovery.

MATERIALS AND METHODS

We retrospectively reviewed 43 patients who underwent conventional FFF condylar reconstruction, and 5 patients who underwent reconstruction by computer-assisted three-dimensional (3D) printing methods. Three-dimensional models were built from cone-beam computed tomography images obtained immediately postoperatively and 1-year postoperatively. The glenoid fossa and fibular condyle centers were used to measure the fibular condyle position in the models. Clinical examination indices, including maximum mouth opening (MMO), pain during chewing/mouth opening, and patient satisfaction with mastication and 1-year outcomes were assessed.

RESULTS

Fibular condyle position changed significantly over 1 year in both groups (P < 0.05). Clinical examination at 1 year after the surgery showed that in the conventional group, the MMO range was ≥ 35 mm in 76.7% of patients and < 35 mm in 23.3% of patients; 4.7% experienced pain during chewing/mouth opening, and 7% were dissatisfied with treatment outcomes. In the 3D printing group, all patients had an MMO range exceeding 35 mm, none had pain, and all were satisfied with functional outcomes.

CONCLUSIONS

The position of the fibular condyle deviates after reconstructive surgery, but it is unlikely to affect functional recovery.

CLINICAL RELEVANCE

These findings can form the basis for evaluation of functional outcomes of patients who have previously undergone condylar reconstruction by FFF.

Are Signs of Degenerative Joint Disease Associated With Chin Deviation?

PURPOSE

Degenerative joint changes commonly affect the temporomandibular joint (TMJ) and can result in chin deviation. However, the extent of degenerative TMJ changes and chin deviation has not been well-characterized. The present study sought to correlate degenerative TMJ changes with condylar volume, grayscale measures, and chin deviation.

MATERIALS AND METHODS

The present cross-sectional study had enrolled women with skeletal Class III malocclusion. Cone-beam computed tomography scans were acquired preoperatively. For each condyle, degenerative TMJ signs were analyzed and the condylar volume and grayscale were measured. The predictor variable was the presence of degenerative TMJ signs, classified as categorical data: 0, if none; 1, only present in 1 joint; and 2, present in both joints. The primary outcome variable was a chin deviation of 3 mm or more. Other associated variables were grouped by age, cephalometric data, and 3-dimensional condylar measurements. Descriptive bivariate statistics were computed, and univariate and multiple logistic regression analyses were conducted to identify any associations between degenerative TMJ disease and chin deviation.

RESULTS

We included 85 patients, who were classified into 2 groups: less than 3 mm of chin deviation (n = 43) and 3 mm or more of chin deviation (n = 42). The presence of more than 10 degenerative TMJ signs was significantly associated with the presence of 3 mm or more of chin deviation (P < .001). In multiple regression models, the presence of subcortical sclerosis in 1 joint and in both joints (adjusted odds ratio [OR], 3.698; 95% confidence interval [CI], 1.051 to 13.012; adjusted OR, 5.001; 95% CI, 1.461-17.119, respectively) correlated significantly with the presence of 3 mm or more of chin deviation (P < .05). The volume difference between the 2 condyles was significantly greater in the group with more than 10 degenerative TMJ signs and 3 mm or more of chin deviation than in the group with 10 or fewer degenerative TMJ signs and less than 3 mm of chin deviation (P = .016 and P < .001, respectively).

CONCLUSIONS

In women with skeletal Class III malocclusion, the presence of more than 10 degenerative TMJ signs increased the prevalence of 3 mm or more of chin deviation. The presence of subcortical sclerosis in either 1 or both joints and volume differences between the 2 condyles were associated with greater chin deviation.

Three-dimensional cone beam computed tomography analysis of temporomandibular joint response to the Twin-block functional appliance

Objective

To propose a three-dimensional (3D) method for evaluating temporomandibular joint (TMJ) changes during Twin-block treatment.

Methods

Seventeen patients with Class II division 1 malocclusion treated using Twin-block and nine untreated patients with a similar malocclusion were included in this research. We collected their cone beam computed tomography (CBCT) data from before and 8 months after treatment. Segmentations were constructed using ITK-SNAP. Condylar volume and superficial area were measured using 3D Slicer. The 3D landmarks were identified on CBCT images by using Dolphin software to assess the condylar positional relationship. 3D models of the mandible and glenoid fossa of the patients were constructed and registered via voxel-based superimposition using 3D Slicer. Thereafter, skeletal changes could be visualized using 3DMeshMetric in any direction of the superimposition on a color-coded map. All the superimpositions were measured using the same scale on the distance color-coded map, in which red color represents overgrowth and blue color represents resorption.

Results

Significant differences were observed in condylar volume, superficial area, and condylar position in both groups after 8 months. Compared with the control group (CG), the Twin-block group exhibited more obvious condyle-fossa modifications and joint positional changes. Moreover, on the color-coded map, more obvious condyle-fossa modifications could be observed in the posterior and superior directions in the Twin-block group than in the CG.

Conclusions

We successfully established a 3D method for measuring and evaluating TMJ changes caused by Twin-block treatment. The treatment produced a larger condylar size and caused condylar positional changes.

[Evaluation of mandibular stability and condylar volume after orthognathic surgery in patients with severe temporomandibular joint osteoarthrosis]

OBJECTIVE

To investigate the effect of preoperative condylar condition for mandible retrognathism deformities with severe temporomandibular joint osteoarthrosis on the stability of the jaw after orthognathic surgery and on the postoperative condylar volume changes.

METHODS

In this retrospective study, from 2014 to 2019, 37 patients including 1 male and 36 female, aged between 21 to 34 years old with an average age of (28.03±6.52) years, were diagnosed with mandible retrognathism deformities with severe temporomandibular joint osteoarthrosis by Peking University School and Hospital of Stomatology and received orthognathic surgery, meeting the inclusion criteria were included. According to the preoperative condylar condition. There were divided into smooth group and non-smooth group, the lateral cephalometric films 1 week (T0), 3 months (T1), 6 months (T2) and 1 year (T3) after surgery were used to establish the coordinate system and cephalometric analysis to determine the stability of the jaw after operation. The three-dimensional model of the condyle was segmented by cone beam computed tomography (CBCT) 1 week (T0), 3 months (T1), 6 months (T2) and 1 year (T3) after surgery and the volume was obtained to evaluate the change of the condyle volume after surgery. CBCT image data was used to evaluate the changes of the condylar condition after surgery, and to clarify the correlation between the postoperative condylar condition and jaw stability. SPSS 20.0 statistical software was used for statistical analysis, Fisher's exact probability methods were used to compare whether there were statistically significant differences in the stability of the mandibular joint at stages T1, T2 and T3 with different preoperative condylar condition.Spearman correlation coefficient analysis and Mann-Whitney test were used to compare whether there were statistically significant differences in the volume changes at stages T1, T2 and T3 after surgery between the two groups.

RESULTS

The recurrence rates of the mandible in the condylar smooth group were T1 36.85%, T2 47.37% and T3 42.11%, respectively. The recurrence rates in the non-smooth condylar group were T1 27.78%, T2 44.44% and T3 55.56%, respectively. There was no statistical difference in the recurrence rates between the two groups at different time points. There was no significant difference in the condylar volume change between smooth group and non-smooth group.

CONCLUSION

For patients with mandible retrognathism deformities with severe temporomandibular joint osteoarthrosis and no significant changes in the condyle observed for one year before surgery, there is no difference in the influence of the preoperative condylar condition on the stability of jaw after operation, and no definite influence on the volume of the condyle after operation. Condylar resorption 3 months after surgery can cause instability of the jaw after orthognathic surgery.

Semi-automated three-dimensional volumetric evaluation of mandibular condyles

OBJECTIVES

The aim of this study is to research the mandibular condyle volumes of the Turkish subpopulation by sex, age, laterality, and posterior occlusal support, to provide volumetric data for young and old patient groups.

METHODS

The CBCT images of 690 condyles from 345 patients (165 females and 180 males) were assessed. Patients aged 18-25 years were chosen for the younger group, and 45-70 years for the older group. The dental statuses of the older patient group were divided into three categories, based on the Eichner index. All the CBCT images were transferred to the three-dimensional volumetric analysis software, ITK-Snap (Penn Image Computing and Science Laboratory (PICSL) at the University of Pennsylvania and Scientific Computing and Imaging Institute (SCI) at the University of Utah) and analyzed with sagittal, coronal, and axial sections. Mandibular condyles were defined using semi-automatic segmentation, then manual segmentation was performed to ensure accuracy. Analyses were performed using MedCalc statistical software. The p value < 0.05 was considered statistically significant.

RESULTS

The mean right condyle volume for the whole sample (n = 345) was 1678.8 mm³ and the left condyle volume was 1661.3 mm³. Males had a larger condyle volume than females in both the younger and older patient groups (p = 0.035, p < 0.01, respectively). The Eichner index did not correlate significantly with condylar volume in the older patient group (p = 0.134, p = 0.122).

CONCLUSION

There were significant differences between the volumes of mandibular condyles for different sex, while there were no significant differences in relation to age, laterality, and posterior occlusal support.

Three-dimensional analysis of temporomandibular joint in Chinese adults with normal occlusion and harmonious skeleton

OBJECTIVE

This study aimed to analyze the detailed three-dimensional measurements of temporomandibular joint (TMJ) in Chinese adults with normal occlusion and harmonious skeleton.

METHODOLOGY

In 51 subjects 102 joints were analyzed using Anatomage Invivo dental 5.4. The measurements include: joints' parameters, position, angulation, and inclination of the condyle and articular fossa as well as 3D volumetric of the joint-spaces. All measurements were statistically analyzed by paired Student's t test to find out the differences between the left- and right sides. Pearson correlation coefficient test was done to figure out the relationship of the TMJ parts in the normal situation.

RESULTS

The inter-condyle distances medially, geometrically, and laterally were 90.2 ± 5.2,107 ± 6.1, and 125 ± 5.5 mm, respectively. However, the 102 condyles were angulated on three planes 54.9º ± 11.2, 71.8º ± 7.3, and 12.5º ± 6.3 at vertical-, horizontal-, and midsagittal planes, respectively. The joint spaces measurements were 2.6 ± 0.7 mm, 2.5 ± 0.8 mm, 2.4 ± 0.7 mm, and 3.3 ± 0.7 mm for anterior-, medial-, posterior-, and superior joints, respectively. The total volume of the whole joint-space was 404.3 ± 71mm³. The left condyle position was on the centric position whereas the right condyle was eccentric (slightly anterior).

CONCLUSION

Chinese subjects are characterized by wide inter-fossa distance and inter-condyle distance; however, no significant correlations with joint spaces in normal occlusion were found. The asymmetries between right- and left mandibular condyle were distinguished in angular and linear-vertical measurements. Finally, this study could be considered as reference data for upcoming research in the Chinese population.

Reliability and accuracy of segmentation of mandibular condyles from different three-dimensional imaging modalities: a systematic review

OBJECTIVE

To critically synthesize the literature surrounding segmentation of the mandibular condyle using three-dimensional imaging modalities. Specifically, analyzing the reliability and accuracy of methods used for three-dimensional condyle segmentation.

METHODS

Three electronic databases were searched for studies reporting the reliability and accuracy of various methods used to segment mandibular condyles from three-dimensional imaging modalities. Two authors independently reviewed articles for eligibility and data extraction.

RESULTS

Nine studies fulfilled the inclusion criteria. Eight studies assessed the condylar segmentation from CBCT images and limited studies were available on non-CBCT three-dimensional imaging modalities. Threshold-based volume segmentation, manual segmentation, and semi-automatic segmentation techniques were presented. Threshold-based volume segmentation reported higher accuracy when completed by an experienced technician compared to clinicians. Adequate reliability and accuracy were observed in manual segmentation. Although adequate reliability was reported in semi-automatic segmentation, data on its accuracy were lacking.

CONCLUSION

A definitive conclusion with regards to which current technique is most reliable and accurate to efficiently segment the mandibular condyle cannot be made with the currently available evidence. This is especially true in terms of non-CBCT imaging modalities with very limited literature available.

Assessment of condylar volume and ramus height in JIA patients with unilateral and bilateral TMJ involvement: retrospective case-control study

OBJECTIVES

The objectives of the study are to analyze volumetric differences of condylar volumes in patients with unilateral and bilateral JIA and to compare results with control condylar volumes.

MATERIALS AND METHODS

Forty-six CBCT images were analyzed for all patients affected by JIA, 37 females and 9 males (mean age 10.8 ± 4.2) with TMJ involvement (19 unilaterally, mean age 10.9 ± 4.5; 27 bilaterally, mean age 10.7 ± 4.5), and 25 CBCT of subjects without diagnosis of JIA were selected as controls (mean age 10.8 ± 4.2 years). In the case of unilateral JIA, condylar volumes and ramus lengths were compared with healthy condyle and with the compromised one. In the case of bilateral JIA, condyle volume and ramus lengths were compared with healthy one. The Shapiro-Wilk test was used to assess whether the data was normally distributed. Paired t test was applied to compare affected and non-affected condyle in the same patients (P < 0.05). Independent t test was used to evaluate whether the difference between the groups were comparable or significantly different (P < 0.05).

RESULTS

For the unilateral JIA group, significant differences comparing affected and non-affected condyles were found. A statistically significant reduction of the volume of the head, neck, and ramus was found in the affected side (P < 0.01). For the bilateral JIA group, statistically significant differences have been found considering the condylar head and neck, the whole condylar volume, and the ramus length compared with the control group (P < 0.05).

CONCLUSIONS

Subjects with unilateral JIA have condyles volumetrically smaller than those of the unaffected side and those found in healthy patients. A considerable decrease of the volume of all the anatomical structures considered in the patients with bilateral JIA was found compared with control group.

CLINICAL RELEVANCE

The study presents the effects of JIA on different anatomical structures highlighting their dimensional changes, whose sequelae are irreversible if not diagnosed and treated early.

Changes in the position of the condyle after bilateral sagittal split ramus osteotomy in patients with mandibular retrusion and protrusion: a new condyle: fossa matching concept

The purpose of this study was to compare the condylar positional changes after bilateral sagittal split ramus osteotomy (BSSRO) in patients with mandibular retrusion and those with mandibular prognathism. We also studied the correlation between the degree of matching of the condyle and fossa, and condylar displacement. Thirty patients with mandibular retrusion (n=11) or mandibular prognathism (n=19) who underwent BSSRO were included. The condylar position was assessed from spiral computed tomographic (CT) scans taken preoperatively, during the first postoperative week, and at least 6 months postoperatively. All data were measured by MIMICS 17.0 and analyzed by Student's t test and Pearson's correlation analysis. The size of the condyles of patients with mandibular retrusion was significantly less than those of patients with mandibular prognathism (491.5 (172.8) compared with 823.2 (212.0) mm³). The size of the glenoid fossa in those with mandibular retrusion (599.6 (110.4) mm³) and those with prognathism (597.6 (151.6) mm³) did not seem to differ. Postoperatively the condyles moved outwards, backwards, and downwards in both groups of patients. Correlation analysis between the condyle:fossa volume ratio and the condylar positional changes showed that a large condyle:fossa volume ratio correlated with the smaller positional changes in the condyle. The condylar position changed immediately after mandibular advancement and setback, and persisted in the long term. Larger condyles tended to have fewer positional changes.

Comparison of condylar morphology changes and position stability following unilateral and bilateral sagittal split mandibular ramus osteotomy in patients with mandibular prognathism

BACKGROUND

Unilateral sagittal split ramus osteotomy (USSRO) is not widely used given the postoperative instability caused by the inevitable rotation of the mandibular segment during surgery. However, the influence of mandibular movement on the condylar morphology and position stability has not been completely explored. The aim of the study was to quantitatively evaluate the effect of USSRO on the condylar surface morphology changes and postoperative stability in patients with mandibular lateral prognathism and compare these findings with the classic bilateral sagittal split ramus osteotomy (BSSRO).

PATIENTS/METHODS

This was a retrospective study involving 134 patients with mandibular lateral prognathism who received USSRO (n = 56) and BSSRO (n = 78) surgery. Here, cone beam computed tomography (CBCT) was performed before surgery (T0), immediately after surgery (T1), and 1 year postoperatively (T2). Differences of condylar sizes, condylar surface deviation, and mandibular positioning parameters (dental midline deviation, SNB, SN-MP) were calculated from T0 to T2. Comparisons were performed at the deviated side or nondeviated side of condyles between the USSRO and BSSRO groups. The relation between the dental midline deviation and condylar surface morphology changes from T0 to T2 were investigated.

RESULTS

Condylar surface morphology changes at the deviated side of temporomandibular joint (TMJ) before and 1 year after the surgery were significantly different between the USSRO and BSSRO groups. The dental midline deviation was related to the changes of condylar volume, surface size and surface deviation at the deviated side of TMJ in patients following USSRO. No significant difference was noted between the USSRO and BSSRO groups for postoperative condylar surface morphology changes at the nondeviated side. In both groups, significant differences between T0 and T1 and no significant difference between T1 and T2 were noted for all of the mandibular positioning parameters.

CONCLUSIONS

Both BSSRO and USSRO exhibit favorable postoperative stability in the correction of mandibular prognathism. After USSRO surgery, condylar surface changes occurred at the deviated side of the TMJ, and the dental midline deviation was closely related to the changes of condylar surface morphology. USSRO represents a stable alternative for minor asymmetric mandibular prognathism correction with the advantages of reduced operating time and surgical trauma.

Tissue Engineering for the Temporomandibular Joint

Tissue engineering potentially offers new treatments for disorders of the temporomandibular joint which frequently afflict patients. Damage or disease in this area adversely affects masticatory function and speaking, reducing patients' quality of life. Effective treatment options for patients suffering from severe temporomandibular joint disorders are in high demand because surgical options are restricted to removal of damaged tissue or complete replacement of the joint with prosthetics. Tissue engineering approaches for the temporomandibular joint are a promising alternative to the limited clinical treatment options. However, tissue engineering is still a developing field and only in its formative years for the temporomandibular joint. This review outlines the anatomical and physiological characteristics of the temporomandibular joint, clinical management of temporomandibular joint disorder, and current perspectives in the tissue engineering approach for the temporomandibular joint disorder. The tissue engineering perspectives have been categorized according to the primary structures of the temporomandibular joint: the disc, the mandibular condyle, and the glenoid fossa. In each section, contemporary approaches in cellularization, growth factor selection, and scaffold fabrication strategies are reviewed in detail along with their achievements and challenges.

Three-dimensional volumetric analysis of mandibular condyle changes in growing subjects: A retrospective cross-sectional study

OBJECTIVE

The purpose of this study is to analyze the mandibular condylar volumein a sample of subjects 11-26 years old.

METHODS

CBCT condylescans from 94 patients (mean age 18.2 ± 4.5 y) acquired with areconstructed layer thickness of 0.5 mm and a 512×512 matrix were examined. Data on condylar volume were compared among three groups with different age ranges: 11-16 years, 17-21years, and 22-26 years. Condylar volumetric measurements were performed with Mimics™ software.

RESULTS

A significant increase in condylar volume from puberty to young adulthood was detected (p < 0.01). Females showed a higher condylar volume in the 17-21 y group compared with the 11-16 y group. Males showed differences among all three groups.

CONCLUSION

The mandibular condyle growth seems to continue at least until 17-21 years in males but seems to stop before 17 years in females.

Linear and Volumetric Mandibular Asymmetries in Adult Patients With Different Skeletal Classes and Vertical Patterns: A Cone-Beam Computed Tomography Study

This study aimed to quantify the height of the mandibular condyle and ramus, condylar volume, and the asymmetry index in adult patients of different sex, skeletal class and vertical pattern using Cone-Beam Computed Tomography (CBCT), and to determine whether there were differences between these groups. The study used CBCT scans of 159 patients with a mean age of 32.32 ± 8.31 years. InVivoDental® software was used to perform both linear (condylar, ramal, and total height) and condylar volume measurements. Linear and volumetric asymmetries were calculated. There were not significant differences between right and left sides. The mean value obtained for condyle height was 7.27 mm, ramus height 42.3 mm, total height 49.6 mm and condyle volume 1907.1 mm3, with significant differences between men and women. Significantly higher values were found for condylar volume in hypodivergent patterns (p = 0.001) and for the asymmetry index of the condylar volume in Class II patients (p < 0.05). The prevalence of relevant asymmetry was high for condyle height and volume (73.1% y 75.6% respectively). Higher height and volume values were found among men, Class III, and hypodivergent patients. Linear and volumetric asymmetries were more prevalent among men, Class III and hyperdivergent patterns.

Developing a reference MRI database for temporomandibular joints in healthy children and adolescents

BACKGROUND

Recognition of normal temporomandibular joints (TMJs) is essential to assess arthropathic changes. Few, if any, prior studies have evaluated the morphological appearance of growing TMJs by magnetic resonance (MR) examinations in the pediatric population.

OBJECTIVE

This study aimed to determine normative osseous appearance of growing TMJs according to age and gender, both qualitatively and quantitatively, concerning structural and bone marrow changes.

MATERIALS AND METHODS

From 1,036 MR scans screened, one joint was included from each of 157 patients (76% female; 2-18 years) presenting with at least one normal-appearing TMJ was included. Quantitatively, mandibular condyle was characterized by measuring the following: (i) head-neck angle, (ii) anteversion angle, (iii) condylar dimensions (mediolateral, craniocaudal and anteroposterior [AP]) and (iv) condylar volume. Furthermore, qualitative categorization of condylar shape, into one of three types, and condylar bone marrow type was performed.

RESULTS

The head-neck angle significantly correlated with age (bivariable regression β =0.60, P<0.001), indicating an increase of 1.6 degrees per year. Except for AP diameter of condyles, all other mandibular dimensions and condylar volume increased with age (β =0.20-0.59, P≤0.001-0.004). Significant age difference was observed among the different condylar shapes (P<0.001), indicating a change from rounded head without anterior tilt to rectangular head with anterior tilt. Lastly, mandibular condylar size, measured by volume and by AP and mediolateral dimensions, appeared larger in males.

CONCLUSION

The morphology of the mandibular condyles changes with age. During development, the shape of the condyles changes from round to rectangular in contour with the development of the anterior condylar tilt, as measured by the head-neck angle.