The Effect of Condylar Regeneration After Different Disc Repositioning Surgeries in Adolescents with Skeletal Class II Malocclusion

Physical therapy and non-surgical manual disc reduction combined with anterior repositioning splint for acute disc displacement without reduction of the temporomandibular joint in adolescents

OBJECTIVES

Current studies on the treatment of adolescent patients with disc displacement without reduction (DDWOR) are limited by short follow-up periods and small sample sizes, and there are few comparative studies on the efficacy of conservative treatment with and without disc reduction for acute DDWOR. This study compared the therapeutic effects of two conservative treatment methods: physical therapy alone and physical therapy combined with non-surgical manual disc reduction and anterior repositioning splints (ARS), in adolescent patients with acute DDWOR.

MATERIALS AND METHODS

This retrospective study included adolescent patients with DDWOR who underwent physical therapy at the Temporomandibular Joint Rehabilitation Department of the Shanghai Ninth People's Hospital from January 2018 to December 2021. Patient assessment data were collected before and after treatment. Patients were followed up through telephone and online questionnaires from March to August 2023.

RESULTS

The results indicate that compared to physical therapy alone, the combination of physical therapy and non-surgical manual disc reduction with ARS showed better short-term efficacy, improved mouth opening, and better long-term pain control. Also, it may be effective in preventing degenerative joint disease.

CONCLUSIONS

This combination therapy is recommended for clinical application in adolescent patients with acute DDWOR.

CLINICAL RELEVANCE

The present research demonstrates the superior efficacy of physical therapy and non-surgical manual disc reduction combined with anterior repositioning splint in adolescent patients with acute DDWOR.

Arthroscopic management and recent advancements in the treatment of temporomandibular joint disorders

In oral and maxillofacial surgery, the evolution of minimally invasive techniques has revolutionised the management of temporomandibular joint (TMJ) disorders. At the forefront of this advancement lies TMJ arthroscopy, a procedure that offers a precise approach to diagnosing and treating joint issues. TMJ arthroscopy is indicated in various clinical scenarios where a detailed evaluation and targeted interventions within the TMJ are required to alleviate symptoms, improve joint function, and enhance the overall quality of life of patients suffering from TMJ disorders.

Effect of occlusal stabilisation splint with or without arthroscopic disc repositioning on condylar bone remodelling in adolescent patients

The aim of this study was to investigate the treatment effects of a stabilisation splint (SS) with and without arthroscopic disc repositioning (ADR) on condylar bone remodelling in adolescent patients with anterior disc displacement without reduction (ADDwoR). Cone beam computed tomography and magnetic resonance imaging were used to analyse condylar bone remodelling, condyle position, and disc position. Twenty-two temporomandibular joints of 14 patients who underwent ADR (age range 12-20 years; mean follow-up 12.5 ± 7.8 months) and 21 temporomandibular joints of 14 patients who did not undergo ADR (age range 13-20 years; mean follow-up 11.1 ± 5.1 months) were included. The change in bone volume (P < 0.001), rate of bone volume change (P < 0.001), and change in condyle height (P = 0.031) were significantly greater in patients with ADR than in those without ADR. The changes in posterior joint space (P = 0.013), superior joint space (P = 0.020), and ratio of condyle sagittal position (P = 0.013) were significantly greater in patients with ADR than in those without ADR. All discs in patients who underwent ADR and one disc in those who did not undergo ADR were backward repositioned. In conclusion, in adolescent patients with ADDwoR, ADR with SS therapy achieved better condyle and disc position than SS therapy alone, and also induced bone generation.

Comparison of disc position stability and condylar bone remodeling between two open disc repositioning surgeries: a retrospective single-center cohort study

BACKGROUND AND OBJECTIVE

Open suturing (OSu) and Mini-screw Anchor (MsA) are two commonly used open disc repositioning surgeries for anterior disc displacement (ADD) of the temporomandibular joint (TMJ). This study assesses the differences in disc position stability (DPS) and condylar bone remodeling (CBR) between these two surgical procedures in a single center.

METHODS

A retrospective cohort study using magnetic resonance imaging (MRI) scans (preoperation, 1 week and 12 mo postoperation) of all patients who had open TMJ disc repositioning surgery from January 2016 to June 2021 at one center through two surgical techniques (OSu and MsA) was performed. The predictor variable was technique (OSu and MsA). Outcome variables were DPS and CBR. During follow-up, DPS was rated as good, acceptable and poor, and CBR was graded as improved, unchanged, and degenerated. Multivariate analysis was used to compare the DPS and CBR at 12 months after adjusting 5 factors including age, sex, Wilkes stage, preoperative bone status (normal, mild/moderate abnormal) and the degree of disc repositioning (normal, overcorrected, and posteriorly repositioned). Relative risk (RR) for DPS and CBR was calculated by multivariate logistic regression.

RESULTS

385 patients with 583 joints were included in the study. MRIs at 12 months showed that 514 joints (93.5%) had good DPS, and 344 joints (62.5%) had improved CBR. Multivariate analysis revealed that OSu had higher DPS (RR=2.95; 95% confidence interval [CI], 1.27 to 6.85) and better CBR (RR=1.58; 95%CI, 1.02 to 2.46) than MsA. Among the factors affecting DPS, females had better results than males (RR=2.63; 95%CI, 1.11 to 6.26) and overcorrected or posteriorly repositioned discs were more stable than normally-repositioned discs (RR=5.84; 95%CI, 2.58 to 13.20). The improvement in CBR decreased with age increasing (RR=0.91; 95%CI, 0.89 to 0.93). Preoperative mild/moderate abnormal bone status had a higher probability of improved CBR compared to normal preoperative bone status (RR=2.60; 95%CI, 1.76 to 3.83).

CONCLUSION

OSu had better DPS and CBR than MsA. Sex and the degree of disc repositioning impacted DPS, while age and preoperative bone status affected CBR.

Analysis of joint protein expression profile in anterior disc displacement of TMJ with or without OA

OBJECTIVE

Anterior disc displacement (ADD) is a common clinical issue and may cause osteoarthritis (OA). However, the research of protein changes in synovial fluid as disease development marker and potential treatment clue is still insufficient.

MATERIALS AND METHODS

We conducted the high-resolution mass spectrometry (MS) of synovial fluid collected from 60 patients with normal disk position to ADD and ADD with osteoarthritis (OA). The proteins with significant changes among the 3 groups were analyzed by biological information and further validated by in primary rat condyle chondrocytes and OA animal model.

RESULTS

FGL2, THBS4, TNC, FN1, OMD etc. were significantly increased in ADD without OA (p < 0.05), which reflected the active extracellular matrix and collagen metabolism. FGFR1, FBLN2, GRB2 etc. were significantly increased in ADD with OA group (p < 0.05), which revealed an association with apoptosis and ferroptosis. Proteins such as P4HB, CBLN4, FHL1, VIM continuously increase in the whole disease progress (p < 0.05). Both the in vitro and in vivo results are consistent with protein changes detected in MS profile.

CONCLUSION

This study firstly provides the expression changes of proteins from normal disc condyle relationship toward ADD with OA, which can be selected and studied further as disease progress marker and potential treatment targets.

Temporomandibular joint disc repositioning and occlusal splint for adolescents with skeletal class II malocclusion: a single-center, randomized, open-label trial

BACKGROUND

Temporomandibular joint (TMJ) disc repositioning through open suturing (OSu) is a new disc repositioning method. Its result for adolescents with condylar resorption and dentofacial deformities combined with and without postoperative occlusal splints (POS) has not been well studied.

OBJECTIVE

This study was to evaluate and compare the effects of OSu with and without POS in the treatment of TMJ anterior disc displacement without reduction (ADDwoR) in adolescent skeletal Class II malocclusion.

METHODS

A total of 60 adolescents with bilateral ADDwoR were enrolled in this study. They were randomly allocated into two groups: OSu with and without POS. Magnetic resonance imaging (MRI) and lateral cephalometric radiographs were used to measure changes in condylar height and the degree of skeletal Class II malocclusion from before operation and at 12 months postoperatively. Changes in these indicators were compared within and between the two groups.

RESULTS

After OSu, both groups exhibited significant improvements in condylar height and occlusion at the end of 12 months follow-up (P < 0.05). The group of OSu with POS had significantly more new bone formation (2.83 ± 0.75 mm vs. 1.42 ± 0.81 mm, P < 0.001) and improvement in dentofacial deformity than the group of OSu only (P < 0.05). The new bone height was significantly correlated with POS (P < 0.001), the changes of SNB (P = 0.018), overjet (P = 0.012), and Wits appraisal (P < 0.001).

CONCLUSION

These findings indicated that OSu can effectively stimulate condylar regeneration and improve skeletal Class II malocclusion in adolescents with bilateral ADDwoR. The results are better when combined with POS.

TRIAL REGISTRATION

This trial was prospectively registered on the chictr.org.cn registry with ID: ChiCTR1900021821 on 11/03/2019.

Review of the studies on the relationship and treatment of anterior disc displacement and dentofacial deformity in adolescents

Anterior disk displacement (ADD) is a common type of temporomandibular joint (TMJ) internal derangement. In adolescents, the relationship between ADD and dentofacial deformities are brought into focus. Whether treatment is needed, or what kind of treatment are effective are still without a consensus. From the literature review, the consequences of ADD without treatment and the effect on disk repositioning were summarized. The results showed that after ADD, condylar height was prone to reduce that may lead to or aggravate dentofacial deformities in adolescents. Disk repositioning could promote the regeneration of condylar bone, thus improving the development of dentofacial deformities.

Stability of the contralateral temporomandibular joint disk position after disk repositioning on one side

OBJECTIVE

To evaluate the stability of the contralateral temporomandibular joint disk position after disk repositioning on 1 side.

STUDY DESIGN

Patients with unilateral anterior disk displacement (ADD) treated by disk repositioning from 2015 to 2019 were included in the study. The contralateral disk status was classified as follows: normal, ADD with reduction (ADDwR), and medial/lateral displacement. At 1-year follow-up, changes in the contralateral disk position were evaluated by MRI.

RESULTS

Two hundred thirty-four patients were included in the study. There were 84 disks with normal position, 51 with ADDwR, and 99 with medial/lateral displacement (M/LD) in the contralateral joint. At 1-year follow-up, all the repositioned disks were stable without relapse. In the contralateral joints, 75% of the disks with normal position were unchanged compared with 43.1% of the ADDwR and 54.5% of the M/LD. ADDwR had the highest rate of changing to ADDwoR compared with the disks in normal position (4.8%) and M/LD (7.1%, χ² = 16.13, P < .001). There were 28.3% of M/LD disks and 3.9% of ADDwR that changed to normal position.

CONCLUSIONS

After unilateral disk repositioning, most of the contralateral disks with normal position were stable. M/LD disks tended to move to normal position, whereas ADDwR was largely changed to ADDwoR.