Temporomandibular joint evaluation with magnetic resonance imaging in children with functional unilateral posterior crossbite, treated with rapid maxillary expansion

Temporomandibular joint articular disc position and shape in skeletal Class III

OBJECTIVE

To compare the position and shape of the temporomandibular joint (TMJ) articular disc among the sagittal and vertical skeletal patterns in Angle Class III, Class III subdivision malocclusion and normal occlusion. The null hypothesis was that there was no difference in disc position and shape in different (1) malocclusions and (2) skeletal patterns.

METHODS

This cross-sectional observational study evaluated 105 patients divided into 3 groups: Class III (33, 9.39 ± 1.96 years), Class III subdivision (45, 9.51 ± 1.59 years) and a normal occlusion (27, 10.24 ± 0.87 years) was included as healthy control. Severity of the maxilla-mandibular anteroposterior discrepancy and vertical facial pattern were determined using 2D cephalometry, and the position and shape of the articular discs were evaluated in magnetic resonance images. Statistical parametric and non-parametric tests and Kappa analysis for intra-observer and inter-observer assessment were used (p ≤ .05).

RESULTS

Significant between-group differences were found in articular disc position. In the normal occlusion group, all the articular discs were well positioned. In Class III and Class III subdivision, the discs were displaced in 30.3% and 12.2% of the TMJs, respectively. Sagittal and vertical skeletal patterns did not affect the findings significantly. The Class III subdivision malocclusion group is probably different from the other groups, showing 97.7% of biconcave discs in both TMJs.

CONCLUSION

The longitudinal follow-up of this sample becomes relevant as the two groups with malocclusion in the pre-peak phase of pubertal growth showed differences in the prevalence of displacement and form of the articular disc, with no association with their vertical facial characteristics.

Biomechanical evaluation of the unilateral crossbite on the asymmetrical development of the craniofacial complex. A mechano-morphological approach

BACKGROUND AND OBJECTIVE

The occlusion effect on the craniofacial development is a controversial topic that has attracted the interest of many researchers but that remains unclear, mainly due to the difficulties on measure its mechanical response experimentally. This mechano-morphological relationship of the craniofacial growth is often explained by the periosteal and capsular matrices of the functional matrix hypothesis (FMH); however, its outcomes have not been analytically demonstrated yet. This computational study aims, therefore, to analytically demonstrate the mechano-morphological relationship in the craniofacial development of children with unilateral crossbite (UXB) using the finite element (FE) method.

METHODS

The craniofacial complex asymmetry of ten children, five of whom exhibit UXB, was 3D-analysed and compared with the biomechanical response computed from a FE analysis of each patient's occlusion. Due to the complexity of the geometry and the multitude of contacts involved, the inherent limitations of the model were evaluated by comparing computed occlusal patterns with those recorded by an occlusal analysis on 3D printed copies.

RESULTS

Comparison's outcomes proved the reliability of our models with just a deviation error below 6% between both approaches. Out of validation process, computational results showed that the significant elongation of mandibular branch in the contralateral side could be related to the mandibular shift and increase of thickness on the crossed side, and particularly of the posterior region. These morphological changes could be associated with periodontal overpressure (>4.7 kPa) and mandibular over deformation (0.002 ε) in that side, in agreement with the periosteal matrix's principles. Furthermore, the maxilla's transversal narrowing and the elevation of the maxillary and zygomatic regions on the crossed side were statistically demonstrated and seem to be related with their respective micro displacements at occlusion, as accounted by their specific capsule matrices. Our results were consistent with those reported clinically and demonstrated analytically the mechano-morphological relationship of children's craniofacial development based on the FMH's functional matrices.

CONCLUSIONS

This study is a first step in the understanding of the occlusion's effect on the craniofacial development by computational methods. Our approach could help future engineers, researchers and clinicians to understand better the aetiology of some dental malocclusions and functional disorders improve the diagnosis or even predict the craniofacial development.

Safety and Effects of the Rapid Maxillary Expander on Temporomandibular Joint in Subjects Affected by Juvenile Idiopathic Arthritis: A Retrospective Study

BACKGROUND

In Juvenile Idiopathic Arthritis (JIA) temporo-mandibular joints are often affected causing skeletal and dental malocclusions. The most frequent condition is mandibular hypoplasia, that may be associated with maxillary hypoplasia. The aim of this retrospective case control study is to investigate the effects and the safety of rapid maxillary expansion (RME) in growing patients affected by JIA. It was evaluated whether RME could be performed without complications on TMJs of JIA patients using DC/TMD protocol, and naso-maxillary transversal parameters were compared with the ones obtained on healthy patients.

METHODS

Twenty-five patients affected by JIA that ceased to manifest TMJ (Temporo-Mandibular Joint) symptoms in the previous year were treated with RME to solve the maxillary transverse hypoplasia. Postero-anterior cephalometric tracings were collected before and after treatment; linear measurements were obtained to study maxillary and nasal cavity modifications. Data were compared to those of a similar group of twenty-five healthy patients. Paired t-test and Independent t-test were used to evaluate changes before and after treatment in each group and to perform a comparison between the groups.

RESULTS

All patients demonstrated a statistically significant increase in nasal cavity width, maxillary width and upper and lower intermolar width. No patients presented a worsening of their TMJs condition. Intragroup comparisons revealed significant changes of cephalometric measurements, but no difference was found when comparing JIA and healthy patients.

CONCLUSIONS

Growing patients with JIA that ceased to show signs of active TMJ involvement for at least one year could be safely treated with RME, expecting similar benefits to those of healthy patients. Dentists and rheumatologists should be informed of safety and potential benefits of palatal expansion in JIA patients in order to improve the outcome of orthodontic treatment and reduce the indication for more invasive procedures (i.e., Surgical Assisted Rapid Maxillary Expansion).

Effects of rapid maxillary expansion on temporomandibular joints

OBJECTIVE

To evaluate the impact of rapid maxillary expansion (RME) on the condylar position, disc joint, joint space, and interarticular relationship in growing patients.

MATERIALS AND METHODS

A systematic search was performed in nine databases. The clinical studies selected included those with pre- and post-magnetic resonance, conventional computed tomography or cone beam tomography in growing patients. Risk of bias assessment was performed using the Cochrane Collaboration tool for controlled clinical studies and National Heart, Lung, and Blood Institute (NHLBI) Quality Assessment for Before-After Studies With No Control Group.

RESULTS

Initially, 4303 records were identified. Only eight studies fulfilled the criteria and were included in the qualitative analysis. Of those, two were controlled clinical studies with a risk of uncertain to high bias. The remaining papers had a low to moderate risk of bias. Results showed that RME in children and adolescents promoted the following: remodeling in the head and or condylar branch, changes in condylar position and joint space, maintenance of improved symmetry between the condyles, and no ability to modify the position or shape of the articular disc.

CONCLUSIONS

RME in growing patients is able, in the short term, to modify the condyle-fossa relationship but does not change the position or shape of the articular disc. The intercondylar symmetric relationship is maintained or improved. Although the NHLBI score shows low to moderate risk of bias, the clinical relevance of these review findings is limited by Cochrane and Grades of Recommendation, Assessment, Development and Evaluation scores.

Effects on the Facial Growth of Rapid Palatal Expansion in Growing Patients Affected by Juvenile Idiopathic Arthritis with Monolateral Involvement of the Temporomandibular Joints: A Case-Control Study on Posteroanterior and Lateral Cephalograms

BACKGROUND

Juvenile idiopathic arthritis (JIA) affecting temporomandibular joints (TMJ) in growing patients results in maxillofacial deformities, especially if only one condyle has been affected by the rheumatic disease. Mandibular hypoplasia is the most common issue and it may be associated with maxillary hypoplasia. The aim of this retrospective case-control study is to evaluate the effects of rapid maxillary expansion (RME) in these patients.

METHODS

25 growing patients affected by maxillary hypoplasia, currently in a quiescent phase of JIA for at least one year and monolateral involvement of the TMJs, were treated with RME. Data gathered from posteroanterior and lateral cephalograms before and after 1 year from RME were compared to those of 25 non-JIA controls.

RESULTS

Nasal cavity width, maxillary width and upper and lower intermolar width statistically increased. Maxillary and mandibular symmetry indexes presented a statistically significant increase, so did the skeletal class. No signs or symptoms of TMJ activity of JIA occurred according to Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) criteria. No difference was found when comparing JIA and non-JIA patients apart from the better improvement of several mandibular symmetry indexes in the affected TMJ side of JIA patients. This event is allegedly due to a worse baseline asymmetry in JIA patients that underwent a bigger relative improvement after treatment.

CONCLUSIONS

Results suggest that solving maxillary hypoplasia and, therefore, premature contacts are likely to have allowed mandibular repositioning and condylar growth. RME is a safe and effective solution that can substantially improve maxillary and mandibular symmetry in growing patients affected by JIA with TMJ involvement.

Positional and dimensional temporomandibular joint changes after correction of posterior crossbite in growing patients: A systematic review

OBJECTIVE

To elucidate the positional and dimensional temporomandibular joint (TMJ) changes after correction of posterior crossbite in growing patients.

MATERIALS AND METHODS

A systematic unrestricted search was done in six databases until June 27, 2017. A manual search in the reference lists of the included studies and gray literature was also performed. The eligibility criteria included randomized controlled trials and prospective nonrandomized controlled clinical trials and a sample of growing subjects with posterior crossbite that required maxillary expansion. Risk of bias assessment was performed using Cochrane's Risk of Bias Tool. The literature search, study inclusion, risk of bias assessment, evaluation of quality of evidence (GRADE), and data extraction were performed by two reviewers independently.

RESULTS

Only two articles were finally eligible to be included in the qualitative analysis. Both studies were RCTs and were assessed as having unclear risk of bias. Meta-analysis was not possible since one study used cone-beam computed tomography as an assessment tool while the other used ultrasonography. One study reported significant reduction in the condylar positional difference between centric and habitual occlusion in the treatment group, while no spontaneous correction of condylar asymmetric position occurred in the control group. The other study reported minor changes of condylar position in both treatment and control groups.

CONCLUSIONS

The current available data provide insufficient and weak evidence to form a solid and firm conclusion. There is poor, very low-quality evidence regarding the positional and dimensional effects of posterior crossbite correction on the TMJs.

Computed Tomographic Evaluation of Condylar Symmetry and Condyle-Fossa Relationship of the Temporomandibular Joint in Subjects with Normal Occlusion and Malocclusion: A Comparative Study

INTRODUCTION

The relationship of the condyle and the mandibular fossa differs in shape with type of malocclusion and skeletal pattern. A review of literature shows till date there are no studies on Temporomandibular Joint (TMJ) condyle-fossa relation to the type of malocclusion based on growth pattern. Computed Tomography (CT) provides optimal imaging of the osseous components of the TMJ.

AIM

The purpose of this study was to investigate the condyle-fossa relationship and the dimensional and positional symmetries between the right and left condyles in subjects with normal occlusion and malocclusion in different growth patterns utilizing the CT scans of the TMJ.

MATERIALS AND METHODS

Sixty subjects with age group of 18-30 years were selected for the study. The sample was divided into three groups based on overbite and growth pattern. The groups included 20 subjects with normal occlusion and average growth pattern, 20 patients with horizontal growth pattern and deep bite, 20 patients with vertical growth pattern and deep bite. The depth of the mandibular fossa, the condyle-fossa relationship, and the concentric position of the condyles were evaluated by the images obtained from the sagittal slices. ANOVA was performed to assess the significance. If it was found significant, post-hoc Tukey's test was performed to see which two groups were statistically significant.

RESULTS

No statistically significant difference was found in the anterior joint space and the superior joint space in horizontal and vertical growers with deep bite. Statistically significant (p <0.05) posterior positioning of the condyles was observed (nonconcentric positioning) in vertical growers with deep bite.

CONCLUSION

There is a significant change in the position of the condyle in vertical growers compared to average and horizontal growers. Left condyle is more anteriorly placed than the right condyle in all the three groups. There is no significant change in the vertical depth of the mandibular fossa in all the three groups.

Temporomandibular joints in asymptomatic and symptomatic nonpatient volunteers: a prospective 15-year follow-up clinical and MR imaging study

PURPOSE

To determine the incidence, prevalence, and progression of temporomandibular joint (TMJ) magnetic resonance (MR) imaging findings and symptoms during 15 years in adult asymptomatic and symptomatic volunteers (nonpatients).

MATERIALS AND METHODS

A regional committee for medical research ethics approved the study, and informed volunteer consent was obtained. Fifty-three volunteers were examined at study inception. For clinical assessment, a self-administered questionnaire was given, followed by an interview with each volunteer at study inception, at 1 year later, and at 15 years later. Bilateral TMJ MR imaging and clinical examination were performed at inception and at 15-year follow-up. The MR images were assessed for disk position, bone status, and joint fluid. All 53 volunteers participated at 1-year follow-up, and 50 of 53 volunteers participated at 15-year follow-up; of these 50 volunteers, 47 underwent MR imaging. The Fisher exact test was used to determine differences between groups, and the Wilcoxon signed-rank test was used to determine differences in prevalence of TMJ symptoms among the three examination times.

RESULTS

At study inception, TMJ disk displacement was observed in 31% of asymptomatic volunteers (nine of 29) compared with 89% of symptomatic volunteers (16 of 18, P < .001). Inceptive TMJ status was maintained after 15 years in 91% (43 of 47). Unilateral progression was observed in four volunteers (9%); one was symptomatic and three were asymptomatic. Progression involved development of new disk displacement (n = 1), development of new bone changes (n = 2), and aggravation from reducing to nonreducing disk displacement (n = 1). Prevalence of TMJ symptoms did not change significantly between examination times (P = .77). TMJ clicking was the most common clinical symptom.

CONCLUSION

Volunteers with mild symptoms had a prevalence of disk displacement of the same magnitude as that reported in patients, although most volunteers, symptomatic as well as asymptomatic, maintained their TMJ status during 15 years.