Association of malocclusion, self-reported bruxism and chewing-side preference with oral health-related quality of life in patients with temporomandibular joint osteoarthritis

Comparison of fixed braces and clear braces for malocclusion treatment

BACKGROUND

To study and compare the effects of clear aligners without brackets and traditional fixed aligners in orthodontic treatment.

METHODS

The samples were collected from January 2022 to April 2023. The control group (n = 26) received orthodontic treatment using traditional fixed appliances. The research group (n = 20) received orthodontic treatment using the clear aligners without brackets. Compare the therapeutic effects and related evaluation indicators between two groups.

RESULTS

The total effective ratio was compared between the 2 groups, and the study group was greater(P < 0.05). After treatment, the detected values of the periodontal condition indicators (plaque index, debris index, and gingival bleeding index), serum inflammatory factors (CRP, IL-6 and TNF-α) of the two groups, were less than before, also were all less than the control group. (P < 0.05). After therapy, in comparison of the control group, the value of mastication efficiency, comfort and psychological evaluation, sleep indicators and the points of the four dimensions of life quality in the study group was greater, and the detection results were obviously greater than before(P < 0.05).

CONCLUSION

In the orthodontic therapy of sufferers with malocclusion, compared with the traditional fixed appliance, the clear aligners without brackets can enhance the treatment effects, improve the periodontal condition and masticatory function, and reduce the inflammatory responses, so that patients can feel more comfortable, thereby improving their psychology, sleep and quality of life. In the future, with the continual advancement of technology and people's pursuit of beauty, the application of clear aligners without brackets in orthodontic treatment will become more and more extensive. The continuous introduction of new materials and new technologies will further improve the effects and comfort of the clear aligners without brackets, reduce treatment time and discomfort, and also reduce patients' resistance to aligners, bringing patients a better treatment experience.

Relationship between Sleep Bruxism Determined by Non-Instrumental and Instrumental Approaches and Psychometric Variables

Sleep bruxism (SB) can be determined with different diagnostic procedures. The relationship between psychometric variables and SB varies depending on the diagnostic method. The aim of the study was to compare the association between SB and oral health-related quality of life (OHRQoL; measured by the Oral Health Impact Profile, OHIP), anxiety (measured by the State-Trait anxiety inventory, STAI), and stress (single scale variable) depending on the diagnostic method in the same sample. N = 45 participants were examined by non-instrumental (possible/probable SB) and instrumental methods (definite SB). The OHIP differed significantly between possible SB (median = 4) and non-SB (median = 0) with W = 115, p = 0.01, and probable SB (median = 6) and non-SB (median = 0) with W = 101, p = 0.01). There was no significant difference in the OHIP score between definite SB and non-SB. For the other psychometric variables, the analyses revealed no significant differences between SB and non-SB in all diagnostic procedures. The results suggest that there is a difference between possible/probable and definite SB with respect to the association with OHRQoL. Certain aspects of possible/probable SB might be responsible for the poor OHRQoL, which are not measured in definite SB.

Loss of Slc39a12 in hippocampal neurons is responsible for anxiety-like behavior caused by temporomandibular joint osteoarthritis

Background

An evident association between mood disorders and TMJ dysfunction has been demonstrated in previous studies. This study observed both the behavioral changes and the pathological changes in hippocampal tissue of rats in an animal model of TMJ-OA by injecting MIA into TMJ.

Methods

Eighteen SD rats were randomly assigned to the NC group and the MIA groups. A TMJ-OA model was established to assess the HWT in the TMJ region, and the rats were subjected to the OFT and EPM. HE, O-fast green staining, qRT-PCR and immunofluorescence were used to detect condylar damage. Serum and hippocampal oxidative stress levels were detected. Functions of genes obtained by RNA-Seq were investigated using H2O2, ZnCl2 and transfection of siRNA on HT22 cells.

Results

Injection of MIA resulted in disorganization of the chondrocyte layer on the condylar surface of rats, with reduced synthesis and increased degradation of the condylar cartilage matrix and reduced HWT. The results of the OFT and EPM showed that the rats in the MIA group developed anxiety-like behavior during the sixth week of MIA injection. Increased Nox4 expression, decreased SOD2 expression, elevated MDA level, and reduced GSH level were detected in serum and hippocampal neurons in the MIA group, with nuclear pyknosis and reduced Nissl bodies observed in neurons. The expression of Slc39a12 in hippocampal neurons of rats in the MIA group decreased. Slc39a12 knockdown in HT22 cells induced increased Nox4 expression, decreased SOD2 expression, increased MDA level, and reduced GSH and intracellular Zn2+. Oxidative stress in HT22 cells after transfection and H2O2 stimulation was reversed when ZnCl2 was added.

Conclusion

Loss of Slc39a12 in hippocampal neurons results in cellular oxidative stress, further leading to neuronal damage. This may potentially explain how TMJ-OA triggers anxiety-like behavior in rats.

Cone-beam computed tomographic characteristics in degenerative temporomandibular joint disease patients with chewing side preference

OBJECTIVES

This study is aimed at assessing the Cone-beam computed tomographic (CBCT) characteristics of temporomandibular joints (TMJ) in degenerative temporomandibular joint disease (DJD) patients with chewing side preference (CSP).

MATERIALS AND METHODS

CBCT images of 98 patients with DJD (67 with CSP and 31 without CSP) and 22 asymptomatic participants without DJD were measured retrospectively to compare the osteoarthritic changes and the morphology of TMJ. Quantitative analysis of the TMJ radiographic images was performed to present a comparison between the three inter-group groups and between the two sides of the joints.

RESULTS

The frequencies of the articular flattening and surface erosion occur more often in the preferred side joints of DJD patients with CSP than the contralateral side. In addition, the horizontal angle of condyle, the depth of glenoid fossa (DGF), and the inclination of articular eminence (IAE) were larger in DJD patients with CSP than that in asymptomatic participants (p<0.05). Also, the condylar anteroposterior dimension of preferred side joints was significantly less than that of non-preferred side (p=0.026), while the width of condyles (p=0.041) and IAE (p=0.045) was greater.

CONCLUSIONS

DJD patients with CSP appear to have a higher prevalence of osteoarthritic changes, with the morphological changes such as flat condyle, deep glenoid fossa, and steep articular eminence, which might be considered the characteristic imaging features.

CLINICAL RELEVANCE

This study found that CSP is a predisposing factor for the development of DJD, and attention should be paid to the existence of CSP in DJD patients during the clinical practice.

Focus Groups to Inform the Development of a Patient-Reported Outcome Measure (PROM) for Temporomandibular Joint Disorders (TMDs)

BACKGROUND

Understanding symptoms of temporomandibular joint disorders (TMDs) can help doctors and patients document, monitor, and manage the disease and help researchers evaluate interventions. Patients with TMDs experience symptoms ranging from mild to severe, primarily in the head and neck region. This study describes findings from formative patient focus groups to capture, categorize, and prioritize symptoms of TMDs towards the development of a patient-reported outcome measure (PROM).

METHODS

We conducted ten focus groups with 40 men and women with mild, moderate, and severe TMD. Focus groups elicited descriptions of symptoms and asked participants to review a list of existing patient-reported outcomes (PROs) from the literature and patient advisor input and speak to how those PROs reflect their own experience, including rating their importance.

RESULTS

We identified 52 distinct concepts across six domains: somatic, physical, social, sexual, affective, and sleep. Focus groups identified the ability to chew and eat; clicking, popping, and other jaw noises; jaw pain and headaches; jaw misalignment or dislocation; grinding, clenching, or chewing, including at night; and ear sensations as most important. Participants with severe TMDs more often reported affective concepts like depression and shame than did participants with mild or moderate TMDs.

CONCLUSION

Findings support PROM item development for TMDs, including selecting existing PROMs or developing new ones that reflect patients' lived experiences, priorities, and preferred terminology. Such measures are needed to increase understanding of TMDs, promote accurate diagnosis and effective treatment, and help advance research on TMDs.

Efficacy analysis of splint combined with platelet-rich plasma in the treatment of temporomandibular joint osteoarthritis

Objective: To evaluate the efficacy of splints combined with PRP for the treatment of temporomandibular joint osteoarthritis. Methods: Thirty-one patients with temporomandibular joint osteoarthritis who were treated with splints combined with platelet-rich plasma (PRP) from January 2021 to June 2021 at the Department of Oral and Maxillofacial Surgery, School of Stomatology, China Medical University (Shenyang, China) were retrospectively reviewed. The VAS scores of all the patients were recorded before and 6 months after treatment, and the maximum comfortable mouth opening was recorded. All data were analyzed by the paired t-test using SPSS software, and a p-value < 0.05 indicated statistically significant differences. Results: Splint + PRP treatment was successful in 31 patients. The mean pretreatment VAS score was 6.1, and the mean VAS score 6 months posttreatment was 4.1. The posttreatment VAS score was significantly lower than the preoperative VAS score (p < 0.05). The mean pretreatment maximum comfortable mouth opening (MCMO) was 27.6 mm, and the mean MCMO 6 months posttreatment was 34.8 mm. The MCMO was significantly increased (p < 0.05). Conclusion: Splint + PRP is an effective treatment for temporomandibular joint osteoarthritis.

Oral health-related quality of life in patients with osteoarthritis of the temporomandibular joint-Results of a systematic review

OBJECTIVES

The aim of this systematic review was to assess the oral health-related quality of life (OHRQoL) of patients with osteoarthritis (OA) of the temporomandibular joint (TMJ).

METHODS

This systematic literature search applied the search terms "oral health-related quality of life AND osteoarthritis of jaw OR arthritis of temporomandibular joint AND oral health-related quality of life" in PubMed, Medline, Web of Science and Scopus. Eligibility criteria were publication until 31 August 2021, examination of children or adults with OA of TMJ, reporting of any OHRQoL measurement and a full text in English language. Two different, independent and experienced reviewers performed this systematic literature search. The analysis of respective data was qualitative. For quality appraisal, the available checklist from the Agency for Healthcare Research and Quality (AHRQ) was applied.

RESULTS

Out of 102 findings, eight studies were included in qualitative analysis. Seven clinical investigations were performed in adults aged between 34 and 43 years. The other included study was performed on children. The quality of two studies was moderate, and six studies were evaluated as of high quality. Most studies applied the 14-item short form of the oral health impact profile (OHIP 14) for assessment of OHRQoL. OHIP 14 ranged between 9.24 and 38.86 points in means of sum score. Comparison with healthy individuals revealed worse OHRQoL of OA patients in two studies. Associations between OHRQoL with either oral health, general quality of life or disease-related parameters were rarely reported and heterogeneous. Five of the included studies reported subscales of OHIP 14, showing an impairment in all subscales.

CONCLUSIONS

There are hints that patients with OA of the TMJ show a reduced OHRQoL. More studies are needed, especially regarding oral health, disease-related parameters and pain intensity and its potential influence on OHRQoL.

Association between Sleep Disorders and Sleep Quality in Patients with Temporomandibular Joint Osteoarthritis: A Systematic Review

Background: Osteoarthritis (OA) is a leading cause of disability, the most common form of chronic disease in the temporomandibular joint (TMJ), and the most severe disease type of temporomandibular disorders (TMD). The etiology of TMD is multifactorial, considering parafunctional habits, sleep bruxism, or sleep disturbance as common factors. Insomnia and apnea are the two most frequent forms of sleep disorders in TMD patients. Due to this, the objective of this systematic review was to highlight whether there is currently scientific evidence in the literature describing that patients with temporomandibular joint osteoarthritis (TMJ-OA) are associated with increased sleep disorders or impaired sleep quality. Methods: This systematic review was completed in accordance with the Preferred Reporting Items for Systematic reviews and Meta-Analysis (PRISMA) statement and was registered with PROSPERO prior to completion of the main search. Original observational studies that analyze the association of sleep disorders and sleep quality in patients with TMJ-OA were included in the present review. Results: 770 studies were screened by abstract and title according to inclusion and exclusion criteria, and finally, 7 articles were included in the qualitative synthesis and a total of 772 patients diagnosed with TMJ-OA. Conclusions: There is insufficient evidence to indicate that patients with TMJ OA are associated with increased sleep disorders or poorer sleep quality.

Functional, physical and psychosocial impact of degenerative temporomandibular joint disease

OBJECTIVES

This study evaluated the functional, physical and psychosocial impacts of TMJ degenerative joint disease (DJD). The bearing of TMJ osteoarthrosis/osteoarthritis and early/late TMJ DJD on oral health-related quality of life (OHRQoL) were also compared.

METHODS

Participants were enrolled from a TMD/oro-facial pain centre. Those diagnosed with intra-articular conditions based on the Diagnostic Criteria for Temporomandibular disorders (DC/TMD) were subjected to CBCT assessment and categorised into four discrete groups: NN-no TMJ DJD and no arthralgia; NA-no TMJ DJD with arthralgia; TO-TMJ osteoarthrosis; and TR-TMJ osteoarthritis. The TO/TR groups were subdivided into early/late TMJ osteoarthrosis (EO/LO) and osteoarthritis (ER/LR). OHRQoL was examined using the OHIP-TMD, and data were appraised with the Kruskal-Wallis/Mann-Whitney U tests (α = 0.05).

RESULTS

The study participant (n = 358) had a mean age of 31.85 ± 12.39 years (85.6% women). Frequencies of the TMD groups were as follows: NN-23.2%; NA-27.1%; TO-19.0%; and TR-30.7%. Participants with TR/NA had significantly worse OHRQoL than those with TO/NN. Additionally, participants with ER/LR reported significantly poorer OHRQoL than their counterparts with EO/LO. For all TMD groups and TMJ DJD subgroups, the psychological discomfort domain was generally the most impaired. Differences in global OHIP scores were significant between participants with and without arthralgia (i.e., NA-NN, ER-EO and LR-LO).

CONCLUSIONS

The presence of TMJ pain appeared to impair OHRQoL more than the severity of TMJ DJD. As psychological domains were most impacted, psychosocial care should be incorporated when managing patients with painful TMJ DJD.

Temporomandibular disorders in patients with polysomnographic diagnosis of sleep bruxism: a case-control study

BACKGROUND

Temporomandibular disorders (TMD) is a collective term that refers to complaints of temporomandibular joint (TMJ) pain, fatigue and/or pain of the craniocervical muscles, limitation of movement of the mandible, and TMJ noises. Sleep bruxism (SB) is a disorder involving rhythmic (phasic) or non-rhythmic (tonic) masticatory muscle activity during sleep and is not a movement disorder or a sleep disorder in otherwise healthy individuals. The present study aimed to support or reject the null hypothesis that there is no association between SB and TMD.

METHODS

The study population was recruited from patients who visited the Artmedica Clinic, Mossoro city, Rio Grande do Norte, Brazil. Patients who underwent polysomnography received information about the research and were invited to participate following the inclusion and exclusion criteria. The study sample consisted of 40 individuals with age ranging from 19 to 76 years. The subjects were administered the questionnaire of the European Academy of Craniomandibular Disorders (AEDC). Those who answered affirmatively to at least one question of the questionnaire were recommended to visit the primary researcher's dental clinic for examination; those who met the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) were evaluated, and their condition was classified into one or more subtypes of TMD. The subjects were divided into 4 groups according to the polysomnographic findings and the responses to the AEDC questionnaire. Of the 40 individuals who answered the AEDC questionnaire and underwent polysomnography, 28 presented with TMD symptoms. The data were expressed as simple frequency and percentage values using statistical software. Values of p < 0.05 were considered to be significant.

RESULTS

The results showed that the frequency of TMD in individuals diagnosed to have SB was 46.4%. According to the DC/TMD of the 28 individuals, the most prevalent TMD subtype was local myalgia (85.7%). Of the total subjects, 32.5% had TMD and SB, 36.4% were males, and in the age range of 31 to 40 years (40%).

CONCLUSION

In this study sample, there was no association between SB as currently defined and TMD, thus confirming previous findings on this topic.

Sleep bruxism and temporomandibular disorders: A scoping review of the literature

OBJECTIVE

To provide a scoping review of the literature by assessing all the English-language papers that investigated the relationship between sleep bruxism (SB) and temporomandibular disorders (TMDs).

STUDY DATA AND SOURCES

A search was performed in the National Library of Medicine (PubMed) and Scopus databases, in order to identify all the articles published assessing the relationship between SB and TMDs, by several different approaches. The selected articles were then structurally read and summarized in PICO tables. The articles were selected independently by the two authors.

STUDY SELECTION

Out of 185 references that were initially retrieved, 47 articles met the inclusion criteria and were thus included in the review. The studies were divided into four categories based on the type of SB assessment: 1. questionnaire/self-report (n = 26), 2. clinical examination (n = 7), 3. electromyography (EMG) (n = 5), and 4. polysomnography (PSG) (n = 9).

CONCLUSIONS

Studies based on questionnaire/self-report SB featured a low specificity for SB assessment, and in general they found a positive association with TMD pain. On the contrary, instrumental studies (i.e., electromyography, polysomnography) found a lower level of association or even a negative relationship between SB and TMD pain. Findings from this updated review confirmed the conclusions of a previous review by Manfredini & Lobbezoo, suggesting that literature findings on the relationship between SB and TMDs are dependent on the assessment strategies that are adopted for SB. Future studies should consider SB as a multifaceted motor behavior that must be evaluated in its continuum spectrum, rather than using a simplified dichotomous approach of presence/absence.

Temporomandibular Joint Osteoarthritis: Regenerative Treatment by a Stem Cell Containing Advanced Therapy Medicinal Product (ATMP)-An In Vivo Animal Trial

Temporomandibular joint osteoarthritis (TMJ-OA) is a chronic degenerative disease that is often characterized by progressive impairment of the temporomandibular functional unit. The aim of this randomized controlled animal trial was a comparative analysis regarding the chondroregenerative potency of intra-articular stem/stromal cell therapy. Four weeks after combined mechanical and biochemical osteoarthritis induction in 28 rabbits, therapy was initiated by a single intra-articular injection, randomized into the following groups: Group 1: AB Serum (ABS); Group 2: Hyaluronic acid (HA); Group 3: Mesenchymal stromal cells (STx.); Group 4: Mesenchymal stromal cells in hyaluronic acid (HA + STx.). After another 4 weeks, the animals were euthanized, followed by histological examination of the removed joints. The histological analysis showed a significant increase in cartilage thickness in the stromal cell treated groups (HA + STx. vs. ABS, p = 0.028; HA + ST.x vs. HA, p = 0.042; STx. vs. ABS, p = 0.036). Scanning electron microscopy detected a similar heterogeneity of mineralization and tissue porosity in the subchondral zone in all groups. The single intra-articular injection of a stem cell containing, GMP-compliant advanced therapy medicinal product for the treatment of iatrogen induced osteoarthritis of the temporomandibular joint shows a chondroregenerative effect.

Evaluation of the effects of bruxism on oral health-related quality of life in adults

Objective: The aim of this study was to evaluate the effects of bruxism on oral health-related quality of life (OHRQoL) in adults in relation to temporomandibular disorders (TMD). Methods: Three hundred-fifteen adults of both sexes were divided into two groups: bruxers (n = 172) and controls (n = 143). The participants with TMD were divided into three subgroups based on myofascial pain, disc displacement, or both. The Oral Health Impact Profile (OHIP-14) was used to assess OHRQoL. Results: Bruxers had poorer OHRQoL than controls, and the highest mean OHIP-14 domain scores were observed in physical pain. Bruxers with TMD had higher total OHIP-14 scores and individual domain scores than those without TMD. Bruxers without TMD demonstrated higher OHIP-14 scores than controls. Conclusion: Bruxism was associated with poor OHRQoL. Where bruxism was accompanied by TMD, OHRQoL could be more negatively affected. The presence of bruxism without TMD was also associated with poor OHRQoL.

Awake bruxism frequency and psychosocial factors in college preparatory students

OBJECTIVE

To assess the frequency of reported masticatory muscles activity during wakefulness (i.e., awake bruxism [AB]), levels of anxiety, depression, stress, and the oral health-related quality of life (OHRQoL) in college preparatory students.

METHODS

Sixty-nine college preparatory students participated in the study. AB was evaluated by the Oral Behaviors Checklist (OBC) and a smartphone-based ecological momentary assessment (EMA; [Bruxapp®]). Anxiety and depression were measured by the Hospital Anxiety and Depression Scale, stress was evaluated by the Perceived Stress Scale, and OHRQoL was obtained by The Oral Health Impact Profile-14. Data were analyzed by Pearson's correlation coefficient (α = 0.05).

RESULTS

The average EMA-reported frequency of AB behaviors was 38.4%. Significant correlations were found between AB and the OBC, anxiety, depression, stress, and OHRQoL (p < 0.001).

CONCLUSION

College preparatory students demonstrated moderate frequency of AB, which was significantly correlated with psychosocial factors.

Bruxism, Related Factors and Oral Health-Related Quality of Life Among Vietnamese Medical Students

Although bruxism is a common issue with a high prevalence, there has been a lack of epidemiological data about bruxism in Vietnam. This cross-sectional study aimed to determine the prevalence and associated factors of bruxism and its impact on oral health-related quality of life among Vietnamese medical students. Bruxism was assessed by the Bruxism Assessment Questionnaire. Temporomandibular disorders were clinically examined followed by the Diagnostic Criteria for Temporomandibular Disorders Axis I. Perceived stress, educational stress, and oral health-related quality of life were assessed using the Vietnamese version of Perceived Stress Scale 10, the Vietnamese version of the Educational Stress Scale for Adolescents, and the Vietnamese version of the 14-item Oral Health Impact Profile, respectively. The prevalence of bruxism, sleep bruxism, awake bruxism, and both conditions in Vietnamese medical students were 51.2%, 38.2%, 23.4%, and 10.4% respectively. Stress, temporomandibular joint pain, masticatory muscle pain, and tooth attrition were associated with the presence of bruxism. Vietnamese medical students were negatively affected by bruxism in terms of oral health-related quality of life.

Local Injection of Growth Hormone for Temporomandibular Joint Osteoarthritis

PURPOSE

Osteoarthritis (OA) of the temporomandibular joint (TMJ) elicits cartilage and subchondral bone defects. Growth hormone (GH) promotes chondrocyte growth. The aim of this study was to evaluate the efficacy of intra-articular injections of GH to treat TMJ-OA.

MATERIALS AND METHODS

Monosodium iodoacetate (MIA) was used to induce OA in the TMJs of rats. After confirming the induction of OA, recombinant human GH was injected into the articular cavities of rats. Concentrations of GH and IGF-1 were measured in the blood and synovial fluid, and OA grades of cartilage and subchondral bone degradation were recorded by histological examination and micro-computed tomography.

RESULTS

MIA-induced OA in the rat TMJ upregulated insulin-like growth factor-1 (IGF-1) rather than GH levels. GH and IGF-1 concentrations were increased after local injection of GH, compared with controls. Locally injected GH lowered osteoarthritic scores in the cartilage and subchondral bone of the TMJ.

CONCLUSION

Intra-articular injection of GH improved OA scores in rat TMJs in both cartilage and subchondral bone of the condyles without affecting condylar bone growth. These results suggest that intra-articular injection of human GH could be a suitable treatment option for TMJ-OA patients in the future.

Changes in masticatory laterality 3 months after treatment with unilateral implant-supported fixed partial prosthesis

OBJECTIVE

This study assessed changes in masticatory laterality in patients with unilateral posterior missing teeth 3 months after treatment with an implant-supported fixed partial prosthesis (ISFPP).

METHODS

Thirty patients with unilateral posterior missing teeth participated in this prospective study. They were treated with one-, two- or three-unit ISFPPs. The control group comprised 10 healthy individuals with complete natural dentition. Each participant performed masticatory assays at baseline and at 3-month follow-up, chewing pieces of silicon inside a latex bag. Masticatory laterality was determined using three different methods: assessment of the first chewing cycle, of all cycles and application of a visual analogue scale. Data were compared using the Kruskal-Wallis or the Mann-Whitney U test as appropriate.

RESULTS

Three months after treatment, a significant change in the asymmetry index towards the treated side and a significant reduction in the Unilateral Chewing Index were observed in the ISFPP group. No significant differences in masticatory laterality between groups were detected at 3-month follow-up, regardless of the method assessed.

CONCLUSION

Treatment with ISFPPs alters the masticatory laterality, moving it to the treated side and increasing the degree of bilateral chewing in patients with unilateral posterior missing teeth.

Association between preferred chewing side and dynamic occlusal parameters

Objectives

Evaluation of dynamic occlusal parameters can help dentists to understand the association of occlusion with the preferred chewing side (PCS) and enable optimal restoration of masticatory efficiency. This study evaluated the association between PCS and dynamic occlusal parameters.

Methods

One hundred participants (50 each, right and left PCS) were included in this study. PCS was determined by the visual spot-checking method, and occlusal analysis was conducted by T Scan. Occlusal parameters evaluated included initial contact, center of force, tooth contact area, occlusal interferences, and occlusal time. Data were assessed by chi-squared test and eta correlation coefficient.

Results

Initial contact towards the PCS was observed in 68% and 70% of right and left unilateral chewers, respectively. Likewise, center of force towards the PCS was present in 72% and 66% of right and left unilateral chewers, respectively. A larger area of tooth contact was predominant towards the PCS in 70% and 72% of right and left unilateral chewers, respectively. Chi-squared analysis showed a strong positive correlation between PCS and occlusal parameters at maximum intercuspation. Eta correlation coefficients between PCS and occlusal interferences, as well as centric and eccentric occlusion, revealed negligible associations.

Conclusion

Dynamic occlusal parameters may be associated with PCS.

Impact of Temporomandibular Disorders and Sleep Bruxism on Oral Health-Related Quality of Life of Individuals With Complete Cleft Lip and Palate

The temporomandibular disorders (TMDs) and sleep bruxism (SB) affect the quality of life (QoL) of the individuals in general. However, the literature lacks studies on individuals with cleft lip and palate (CLP). Thus, this study aimed to evaluate the impact of TMD and SB on the oral health-related quality of life (OHRQoL) of individuals with CLP. Thirty-six individuals, both genders, aged between 30 and 50 years, at routine treatment in the Dental Prosthesis Sector of Hospital for Rehabilitation of Craniofacial Anomalies-University of São Paulo were selected and divided into the following groups: G1-unilateral complete CLP (n = 22) and G2-bilateral complete CLP (n = 14). Three questionnaires were applied: Oral Health Impact Profile (OHIP-14), SB self-report and Research Diagnosis Criteria for TMD. Fisher test, Mann-Whitney test, and t test were applied to verify values between TMD, SB, gender, and OHIP-14 (P < 0.05). The mean OHIP-14 score was of 5.80, and females had higher (8.58) OHRQoL than males (3.31). There was association with gender and OHRQoL (t test, P = 0.006), TMD with OHRQoL (Mann-Whitney test, P = 0.036), and TMD and SB (Fisher test, P = 0.006). Temporomandibular disorder was diagnosed in 30% of the individuals. Of these, 16.66% did not present SB, while 13.88% presented it. The association TMD versus SB showed statistically significant differences and 83.33% of the individuals reporting SB also had TMD. Based on this study, the authors can conclude that: TMD impacts OHRQoL in CLP patients, females are more affected in their OHRQoL than males, SB was strongly associated with TMD.

Temporomandibular Joint Regenerative Medicine

The temporomandibular joint (TMJ) is an articulation formed between the temporal bone and the mandibular condyle which is commonly affected. These affections are often so painful during fundamental oral activities that patients have lower quality of life. Limitations of therapeutics for severe TMJ diseases have led to increased interest in regenerative strategies combining stem cells, implantable scaffolds and well-targeting bioactive molecules. To succeed in functional and structural regeneration of TMJ is very challenging. Innovative strategies and biomaterials are absolutely crucial because TMJ can be considered as one of the most difficult tissues to regenerate due to its limited healing capacity, its unique histological and structural properties and the necessity for long-term prevention of its ossified or fibrous adhesions. The ideal approach for TMJ regeneration is a unique scaffold functionalized with an osteochondral molecular gradient containing a single stem cell population able to undergo osteogenic and chondrogenic differentiation such as BMSCs, ADSCs or DPSCs. The key for this complex regeneration is the functionalization with active molecules such as IGF-1, TGF-β1 or bFGF. This regeneration can be optimized by nano/micro-assisted functionalization and by spatiotemporal drug delivery systems orchestrating the 3D formation of TMJ tissues.