Dimensional and positional temporomandibular joint osseous characteristics in normodivergent facial patterns with and without temporomandibular disorders

A CBCT study of changes in temporomandibular joint morphology with immediate implant placement and immediate loaded full-arch fixed dental prostheses

BACKGROUND

Dental implants are becoming a popular treatment of choice. Immediate implant placement with immediate loaded full-arch fixed dental prostheses (IPILFFDP) presents an attractive solution for edentulous and partially edentulous patients because of its high success rate, reduction in overall treatment time, and improved esthetics. However, whether it can minimize the risk of temporomandibular disorder (TMD) has not been previously studied.

OBJECTIVE

To quantitatively evaluate the temporomandibular joint (TMJ) morphology changes before and after IPILFFDP, using cone beam computed tomography (CBCT).

METHODS

Twelve participants without TMJ symptoms undergoing IPILFFDP were included in the study. Preoperative and 1-year postoperative assessment of CBCT scans were performed on 18 items related to TMJ and vertical dimensions. Mimics software was used for data analysis. T-test, Pearson, and Spearman correlation analyses were performed.

RESULTS

There were no significant differences in bilateral joints between pre and post IPILFFDP. Compared with pre-treatment CBCT, post-treatment CBCT showed a significant increase in posterior joint space. There was an approximately 2 mm increase in the vertical dimension after IPILFFDP, which is correlated with an increase in the medial joint space.

CONCLUSIONS

For patients without TMJ-related signs and symptoms, the IPILFFDP could keep the neuromuscular memory of patient's facial muscles and occlusion, and use adapted centric posture as a guide, which led to more precise restoration of the original jaw position and may shed light in future related clinical studies.

The preliminary study of the effects of individual musculoskeletally stable position in the treatment of temporomandibular disorders

BACKGROUND

Temporomandibular Disorders (TMD) is the dysfunction of group of muscles and bones in the joint area, the main symptoms of TMD are the pain of the chewing muscles and (or) the temporomandibular joints, mandibular movement disorders and joint noise. This study was designed to explore the therapeutic effects following Individual Musculoskeletally Stable (IMS) position stabilization splint therapy for TMD patients using Fricton index, cone beam computed tomography (CBCT) and surface-Electromyogram (sEMG).

METHODS

In this study, we enrolled 31 TMD patients (ranging from 18 to 26 years old, including 7 males and 24 females), first Fricton index was used to evaluate the clinical curative effect of TMD with the treatment of IMS stabilization splint; then CBCT was used to observe the TMJ condylar position changes of TMD before and after the treatment of IMS stabilization splint; finally sEMG was used to observe the changes of electromyography of anterior temporalis (AT) and masseter muscles (MM) of TMD before and after the treatment of IMS stabilization splint.

RESULTS

The course of treatment was 6-8 months, with an average of 7.6 months. After the IMS stabilization splint treatment, TMD symptoms relieved, especially in pain, mandibular movement disorder, but still slightly inferior in the treatment of joint noise. And there was a statistically significant difference in the anterior and inner joint space, the condyle had the tendency of moving forward and outward. AT presented reduction significantly of EMG value at rest position after treatment.

CONCLUSIONS

IMS stabilization splint is a therapeutic reversible treatment for TMD, especially for pain and mandibular movement disorder; it produces effects of forward and outward condylar movement and elimination of the masticatory muscles antagonism.

Quantitative and qualitative condylar changes following stabilization splint therapy in patients with temporomandibular joint disorders with and without skeletal lateral mandibular asymmetry: a cone beam computed tomographic study

BACKGROUND

Temporomandibular disorders (TMDs) encompass pain and dysfunction in the jaw, muscles, and adjacent structures. This study aimed to explore the quantitative (condylar position, morphology) and qualitative (bone mineral density (BMD)) therapeutic outcomes following a stabilization splint (S.S.) therapy in adult patients diagnosed with TMD (Arthralgia) with/without lateral mandibular asymmetry (MA) using cone beam computed tomography (CBCT).

METHODS

In this retrospective clinical study, 60 adult TMD patients who received S.S. therapy were enrolled and allocated into the TMD group (TMDG) and TMD with MA group (TMD + MAG). The diagnosis was made according to the Diagnostic Criteria for TMD (DC/TMD) AXIS I. MA was measured from the mid-sagittal plane to the Menton point. CBCT was used to scan the temporomandibular joints pre- (T0) and post- (T1)-treatment for three-dimensional analysis. Intra- and intergroup statistical comparisons were performed using the Wilcoxon signed ranks and the Kruskal‒Wallis test.

RESULTS

For quantitative comparisons, there was a statistically significant difference between T0 and T1 in the joint spaces of TMD + MAG (anterior, superior, posterior, and coronal lateral on the deviated side as well as in the superior, coronal medial joint space of the contralateral side). Morphologically, the deviated side had a narrower condylar width, reduced condylar height, and a steeper eminence angle. In contrast, the contralateral side tended to have a greater condylar length. For qualitative measurements, BMD also showed statistical significance between T0 and T1 in the majority of the condyle slopes (AS, SS, PS, and LS on the deviated side and in AS and MS on the contralateral side) of TMD + MAG. Additionally, only the AS and PS showed significance in TMDG.

CONCLUSION

Multiple joint space widening (AJS and CMS) and narrowing (SJS, PJS, and CLS) could characterize the deviated side in TMD + MA. Factors like narrower condylar width, reduced condylar height, and steeper eminence angle on the deviated side can worsen TMD + MA. Proper alignment of the condyle-disc position is essential for optimal function and load distribution, potentially affecting bone mineral density (BMD). MA plays a prominent role in disturbing bone densities. S.S. therapy shows more evident outcomes in TMD + MAG (on the deviated side compared to the contralateral side) than the TMDG.