The role of orthodontics in temporomandibular disorders

Exploring the association between orthodontic treatment and temporomandibular disorders in pediatric patient: A retrospective study

OBJECTIVE

This retrospective study aimed to investigate the association between orthodontic treatment and development of temporomandibular disorders (TMDs) in pediatric patients.

METHODS

This study analyzed 122 pediatric patients (age 10-18 years) who underwent orthodontic treatment. The inclusion criteria included comprehensive orthodontic records and substantial clinical documentation, while the exclusion criteria targeted preexisting TMDs or syndromes affecting the temporomandibular joint. Demographic details, treatment characteristics, and radiographic analyses, including standardized cephalometric measurements, were recorded. Clinical records were systematically reviewed for signs and symptoms of TMD, with categorization based on TMD severity using the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD).

RESULTS

Demographic characteristics revealed a mean age of 14.2 years, with a sex distribution of 36.9% males and 63.1% females. Pain, clicking/popping sounds, and limited jaw movement were reported by 23.0%, 16.4%, and 12.3% of the patients, respectively. TMD severity classification showed that 73.8% had no symptoms, 20.5% had mild symptoms, 4.1% had moderate symptoms, and 1.6% had severe symptoms. Statistical analyses revealed a significant association between TMD symptoms and sex (P = 0.023). Correlations among TMD severity, treatment duration (P = 0.036), and cephalometric changes were observed. Radiographic findings showed a moderate correlation with the gonial angle (r = 0.42) and a strong correlation with the condylar position (r = 0.58).

CONCLUSION

This study provides insights into the complex relationship between orthodontic treatment and TMD development in pediatric patients. These findings suggest potential associations between treatment characteristics, cephalometric changes, and TMD symptoms.

Effect of maxillary molars distalization using clear aligners and fixed orthodontic appliances on the positional and dimensional temporomandibular joint parameters: a three-dimensional comparative study

OBJECTIVE

The use of clear aligners (CAs) for orthodontic treatment has substantially increased in recent decades. However, limited empirical evidence exists regarding their potential effects on the temporomandibular joint (TMJ). The aim of this study was to assess the effect of maxillary molar distalization on the positional and dimensional TMJ parameters between CAs and conventional fixed orthodontic appliances (FAs) in skeletal class II malocclusion.

METHODS

This is a retrospective cohort study examined 70 adult patients with skeletal class II malocclusion with similar baseline characteristics based on American Board of Orthodontics (ABO) discrepancy index scores. The patients were treated by maxillary distalization movement by CAs or FAs, of which there were two equal groups of 35 patients were included in each group. CBCTs on TMJs were performed before and after treatment through Anatomage Invivo Dental 6.0. The measured parameters included inclination, position, condyle and articular fossa dimensions, and the volumetric joint spaces.

RESULTS

In both groups, linear measurements of the maxillary molar position revealed significant improvement after treatment (P < 0.001). Regarding TMJ parameters, intra-group comparisons revealed significant changes in FA group in the anterioposterior condylar inclination and condylar position across the three planes. Additionally, the pretreatment-centric condylar position in the glenoid fossa was 45.7% and 40% in the CA and FA groups, respectively. After treatment, these percentages changed to 51.4% and 31.4%, respectively. In inter-group comparisons, significant changes were noted in the mediolateral condylar position, which was more inward in the FA group than the CA group.

CONCLUSION

The FA group had more significant dimensional and positional changes in the mandibular condyle than the CA group; nevertheless, the changes are considered clinically negligible.

The Temporomandibular Joint and the Human Body: A New Perspective on Cross Talk

Background: As a unique joint that facilitates the articulation of the upper and lower jaws, the temporomandibular joint (TMJ) is concerned with several critical functions, such as speech and mastication. Pain that can become incapacitating is a result of temporomandibular disorders (TMDs), which are complex disorders affecting the masticatory muscles and the TMJ. Several anomalies and TMDs have an interdisciplinary relationship. Complementary and concurrent disorders may be caused by occlusal anomalies, psychological disorders, and changes in spine posture. Methods: This article examines the clinical characteristics of TMDs, their classification, their etiological factors, and the impact of TMJ disorders on the human body with reference to their anatomies and histological structures. Results: The clinical picture of some TMJ pathologies may be unknown, so certain biomarkers, such as cytokines, may be useful for an accurate diagnosis as they are frequently seen in TMJ disorders. Furthermore, novel therapeutic approaches that target pro-inflammatory cytokines and treat TMDs by using tissue engineering and regenerative medicine while permitting TMJ cartilage and bone regeneration may offer numerous benefits that require clinical translation. Conclusions: Implementation of recent modalities such as microvesicles and platelet-rich plasma in growth factors may provide a promising approach to enhance bone formation. In addition, we target different biological markers that give insights into the introduction of new pharmaceutical agents for therapy.

Evaluation of anterior teeth crown-root morphology and alveolar bone structure in patients with closed deep overbite using cone beam computed tomography

This retrospective study used cone-beam computed tomography to investigated the crown-root morphology and alveolar bone structure in incisors region in subjects with closed deep overbite and comparison the difference between gender and age. The CBCT images for 40 subjects (group C) with Angle II division 2 were selected from patients of the HeFei Stomatological Hospital from November 2023 to March 2024.20 individual normal occlusion subjects (group A),20 patients with Angle II division 1(group B) were included. The crown-root ratio of the maxillary and mandibular anterior teeth, crown-root angle and alveolar bone structure were measured on the CBCT images, the data were statistically analyzed. In addition to mandibular lateral incisor, the crown-root ratio of maxillary and mandibular anterior teeth in the Class II division 2 group was higher than that in the individual normal occlusion group and the Class II division 1 (P < 0. 05). The crown-root angle of maxillary anterior teeth in the Class II division 2 group was smaller than that in the individual normal occlusion group and the Class II division 1 (P < 0. 05). The alveolar bone thickness of the maxillary central incisor was comparatively smaller, while the alveolar bone height was relatively higher in the Class II division 2 group. Age and gender were associated with change in root lengths and crown-root angle for the Class II division 2 group (P < 0. 05). Patients with closed deep overbite malocclusion exhibit a significant difference compared to the controls for most measurements. The patients presenting with Class II division 2 malocclusion exhibit excessive inward positioning of the anterior teeth, resulting in evident crown-root angle, a large crown-root ratio, and minimal labial alveolar bone. In order to keep the tooth movement within the safe range of alveolar bone movement, it is necessary to strictly control the torque and use appropriate orthodontic force to reduce the risk of bone fenestration, bone dehiscence, gingival recession and root resorption.

[Skeletal anchorage combined orthodontic treatment of temporomandibular disorder]

Az állkapocsízületi megbetegedés az orofacialis fájdalmak leggyakoribb formája. Napjainkban a felnőtt populáció 15%-át, míg a serdülőkorúak 7%-át érinti. Jellemzői közé tartozik az izomzatból és/vagy a temporomandibularis ízületből származó fájdalom és az állkapocsmozgásokat kísérő hangjelenségek, emellett az izomfáradás, a szájzár és a fogkopási jelenségek. Az állkapocsízületi diszfunkció miatt létrejövő krónikus fájdalom a páciens pszichés állapotának romlásához vezethet, és negatívan befolyásolhatja életminőségét. Mivel az állkapocsízület és a fogazat között szoros kapcsolat áll fenn, a meglévő harapás bárminemű módosítása esetén feltétlenül szükséges gnatológiai szempontokat is figyelembe venni. A fogszabályozó kezelésre tekinthetünk az occlusio irányított megváltoztatásaként is, ezért a kezelés megtervezésekor a lehető legnagyobb figyelmet kell fordítani az állkapocsízület stabilitásának (ortopédiai stabilitás) megtartására, mivel ez szoros összefüggést mutat az állkapocsízületi egészséggel. Amennyiben a gnatológiai szempontok a kezelés megtervezése során nem teljesülnek, a megváltoztatott harapási helyzet vezethet craniomandibularis diszfunkcióhoz, másrészről az ortopédiai stabilitás helyreállítása a panaszok csökkentésének hatékony módja lehet. Esetbemutatásunk és rövid szakirodalmi összefoglalónk célja, hogy áttekintést adjunk az állkapocsízületi panaszok ortopédiai instabilitásból adódó kórokairól, a stabil és instabil occlusio jellemzőiről, tünettanáról, továbbá az ízületi elváltozás lehetséges megelőzéséről és terápiás lehetőségeiről. Orv Hetil. 2024; 165(37): 1472–1477.

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.

Adolescent Patient's Perceptions During Treatment With Class II Elastics

The article presents a case of a 13-year-old adolescent male patient who started orthodontic treatment at the age of 12. Before treatment, he was diagnosed with narrow maxilla, proclination of upper incisors, deep overbite, distal occlusion bilaterally with significant sagittal overjet in frontal area, skeletal Class II, and hypodivergent growth pattern. During treatment, the patient is in his pubertal growth spurt. About 2 months after intermaxillary Class II elastics (1/4 heavy, 6.5 Oz) were applied, he complained of pain during mastication, wide opening of the mouth, and sometimes during protrusive and lateral movements in the right TMJ. The TMJ X-ray examination did not reveal abnormal morphological changes. Occlusion was evaluated by an electromyographic device, Teethan. The result was typical for Class II malocclusion. During the bilateral palpation of the zones of TMJ and opening of the mouth and chewing, the patient reported pain on the right side. There was no clicking in the joint. The elastic wear was stopped, and soon afterwards, the pain disappeared. These complaints point to a possible relationship between orthodontic treatment and TMJ pain. However, the disappearance of complaints after the removal of the Class II elastics points that the temporomandibular joint disorder (TMD) symptoms are reversible and resolved.

Lessons to be learned when designing comprehensible patient-oriented online information about temporomandibular disorders

BACKGROUND

Temporomandibular disorders (TMD) are a prevalent ailment with a global impact, affecting a substantial number of individuals. While some individuals are receiving treatment from orthodontists for TMD, a significant proportion of individuals obtain knowledge through websites.

OBJECTIVES

Our purpose had been to evaluate, from a patient-oriented perspective, the readability of home pages of websites scored in the 10 most prominent devoted to TMD. We also determined what level of education would have been needed to get an overview of the information on the websites under scrutiny. This approach ensures that our findings are centred on the patient experience, providing insights into how accessible and understandable websites about TMD.

METHODS

We determined the top 10 patient-focused English language websites by searching for 'temporomandibular disorders' in the 'no country redirect' plugin of the Google Chrome browser (www.google.com/ncr). The readability of the texts was assessed using the Gunning fog index (GFI), Coleman Liau index (CLI), Automated readability index (ARI) Simple Measure of Gobbledygook (SMOG), Flesch Kincald grade level (FKGL), Flesh reasing ease (FRE) (https://readabilityformulas.com).

RESULTS

The mean Flesch reading ease index score was determined to be 48.67, accompanied by a standard deviation of 15.04 and these websites require an average of 13.49 years of formal education (GFI), with a standard deviation of 2.62, for ease of understanding.

CONCLUSION

Our research indicates that a significant proportion of websites related to TMD can be defined as a level of complexity that exceeds the ability to read comprehension of the general population.

Prevalence of condylar morphological changes in individuals with class II malocclusion

This observational, cross-sectional study with retrospective collection was aimed to evaluate the prevalence of morphological changes in mandibular condyles in individuals with class II malocclusion, classified according to different vertical growth patterns (brachyfacial, mesofacial, and dolichofacial), through cone beam computed tomography (CBCT). Seventy CBCT images (140 mandibular condyles) were selected from individuals without orthodontic treatment, of both sexes, aged between 25 and 50 years. No statistically significant differences were found between facial patterns; however, there was a higher relative prevalence of bone changes in dolichofacial individuals with flattening (62%), sclerosis (44%), and subchondral bone cyst (20%). Erosion and osteophytes prevailed in mesofacial (39%), and brachyfacial individuals (32%), respectively. Thus, there was no statistically significant difference in the prevalence of degenerative changes between the vertical skeletal patterns. Flattening was the most prevalent change, whereas subchondral bone cyst was the least prevalent among the three groups studied. The observational design of this study makes it possible to analyze image banks to verify the correlation of morphological changes in the temporomandibular joint in different facial patterns in patients with class II malocclusion. A limitation of the study is that clinical characteristics were not evaluated.

The Role of Malocclusion and Oral Parafunctions in Predicting Signs and Symptoms of Temporomandibular Disorders-A Cross-Sectional Study

BACKGROUND

The aim of this study was to examine to what extent malocclusion and parafunctional habits contribute to the development of signs and symptoms associated with temporomandibular disorders (TMD) in schoolchildren with mixed dentition in Croatia in a sample of 338 children, aged 9 to 15 years.

METHODS

TMD signs and symptoms assessed by the clinician were joint function and pain, masticatory muscles tenderness, range of mandibular motion, and joint sounds. To evaluate subjective symptoms and parafunctions, children and parents were asked about the presence of headaches, jaw locking, temporomandibular joint (TMJ) sounds, pain during mouth opening, or bruxism, as well as parafunctions like biting pencils or nails, chewing hard candies or ice, daily gum chewing, opening bottles with teeth, engaging in jaw play, thumb-sucking, and clenching/grinding teeth.

RESULTS

At least one symptom of a TMD was pronounced in 142 participants (42.0%). The most commonly reported parafunction was pencil or nail biting, present in 25.1% of participants. Class II malocclusion increased the likelihood by 2.6 times, pencil or nail biting by 2.34 times, and clenching/grinding teeth by 8.9 times that the subject would exhibit at least one TMD symptom.

CONCLUSIONS

Every child with mixed dentition should undergo a brief examination of the TMJ, especially in cases of Class II malocclusion, pencil or nail biting, and teeth clenching or grinding, as these have all been identified as significant risk factors that increase the likelihood of experiencing TMD symptoms. This highlights the need for proactive screening and assessment by healthcare providers to reduce the risk and prevalence of TMDs in affected children and ensure timely diagnosis and treatment.

Occlusal Features and Temporomandibular Joint Disorder: A Cross-Sectional Study

Background

Understanding the correlation between temporomandibular joint disorder (TMD) parameters and various occlusal features can play a significant role in diagnosing and treating occlusal problems and their potential consequences on TMD.

Objectives

To investigate the relationship of occlusal features and some of the TMD parameters. Study Design and Sampling. The current cross-sectional study was conducted on 200 TMD patients seeking dental treatment at different dental centers in Baghdad city, aged 18-35 years. All participants underwent assessment for occlusal features, which were molar and canine classifications, overjet, posterior buccal or lingual crossbites, and overbites, and TMD parameters (muscle pain, TMJ pain, and clicking) using the Chi-square test for statistical analysis.

Results

Regarding molar classification, there were strong positive correlations between subjects with TMD and having different molar classifications (class I, II, and III) bilaterally or unilaterally; furthermore, there were strong positive correlations between subjects with TMD and having different canine classifications. Moreover, there were significant correlations between subjects with increased, normal, or decreased overjet and the TMD parameters. In addition, there were weak positive correlations between TMD occurrence and buccal or lingual posterior crossbite. On the other hand, there were significant correlations between subjects with a decreased overbite and the presence of TMD parameters.

Conclusion

TMD had a multifactorial background rather than dependability on a specific molar or canine classification type. There was also a correlation between overjet and TMD muscle pain, while decreased overbite was correlated to muscle and TMJ pain. Conversely, there is no vital correlation between posterior buccal or lingual crossbite occurrence and TMD parameters.

Impact of professional, recreational and nonsinging on temporomandibular disorders - a comparative study based on a self-assessment questionnaire

BACKGROUND

This study investigates the relationship between professional and recreational singing on temporomandibular disorders (TMDs) in women compared to a nonsinging control group.

METHODS

A total of 288 female subjects between the ages of 18 and 45 participated in the self-assessment questionnaire including demographic data, as well as questions on vocal practice and TMDs symptoms. Depending on the singing time per week, the (non)vocalists were assigned to the groups professional (n = 96), recreational (n = 96) and nonsingers (n = 96).

RESULTS

The TMDs prevalence in professional singers (42%) was higher than that in recreational singers (31%) and noticeably higher than that in nonsingers (25%). The Fisher-Freeman-Halton exact test showed that the differences between the groups were not noticeable (p = .053) but could be formulated as tendencies. The professionals suffered much more from restricted jaw movement (p = .004; OR = 2.718; 95% CI = 1.409-5.242), temporomandibular joint sounds (p < .009; OR = 2.267; 95% CI = 1.264-4.064) and temporomandibular pain (p = .010; OR = 2.333; 95% CI = 1.264-4.308) than nonsingers.

CONCLUSIONS

Singing might have an enhancing effect on the appearance of TMDs. In particular, professional singers suffered more from self-reported TMDs than recreational singers and nonsingers. In addition to the high level of physical workload if participating in professional singing, the psychosocial impact should be investigated more in further studies. No new treatment strategies resulted from this study, as the etiological significance of singing is still unclear. Knowledge about risk factors for multifactorial TMDs can help practitioners and patients prevent and treat TMDs.

The association between orthodontic treatment and temporomandibular disorders diagnosis and disease characteristics

BACKGROUND

The association between orthodontic treatment and temporomandibular disorders (TMD) has been contentious in the literature.

OBJECTIVES

To analyse the associations between orthodontic treatment and TMD diagnosis and diseases characteristics.

METHODS

This case-control study included 291 individuals, 192 TMDs and 99 controls. All patients underwent assessment based on a questionnaire and a clinical examination according to Axis I of the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD). Differences in orthodontic treatment between TMDs and controls, as well as across different TMD diagnoses within the TMD group were analysed. Patients who underwent orthodontic treatment were compared to those who did not, regarding their trauma history, bruxism, aggressive teeth brushing, level of oral hygiene, pain scores, muscle tenderness scores and subjective sleep quality.

RESULTS

Of the 291 participants, 119 (40.9%) underwent orthodontic treatment and 172 (59.1%) had no orthodontics experience. Orthodontic treatment included: mandibular orthodontic treatment (102 subjects) and maxillary orthodontic treatment (113 subjects) of those 47 used a headgear. Following multivariate analysis among TMDs, orthodontic treatment was associated with a good level of oral hygiene versus poor (Odds ratio [OR]: 5.17 [1.04-25.59]), lower number of tender muscles [OR = 0.84 (0.74-0.96)] and lower (better) Pittsburgh Sleep Quality Index (PSQI) scores (OR = 0.86 [0.76-0.97]). None of the studied parameters maintained a statistically significant association with orthodontic treatment in the multivariate analysis among the entire study population.

CONCLUSIONS

Utilising a holistic approach, this study supports the main hypothesis that orthodontic treatment is not associated with TMD diagnosis and disease characteristics.

The effect of temporomandibular joint dysfunction on the craniocervical mandibular system: A retrospective study

BACKGROUND

Temporomandibular disorders are the most common condition affecting the orofacial region, resulting in pain and dysfunction.

OBJECTIVE

This study aimed to elucidate the ambiguous association between cervical features and temporomandibular disorders by measuring the rotations between the skull-atlas, atlas-axis and mandible-atlas and examining the relationship between these rotations and temporomandibular disorders.

METHODS

Cone-beam computed tomography (CBCT) images from 176 patients, 97 females and 79 males with an average age of 25.7 years were used in this study. The patients were divided into two groups: those with joint dysfunction (n = 88) and those without (n = 88). The study employed various methods to determine rotations in the skull-atlas, atlas-axis and mandible atlas based on anatomical landmarks and measurements. These methods include the use of specific planes, angles and distances to identify and measure rotation. Data analysis was performed using the TURCOSA statistical software (Turcosa Analytics Ltd Co, Turkey, www.turcosa.com.tr).

RESULTS

The results showed that the degree of rotation between the skull and the atlas was higher in the TMD group than in the control group (p < .001). Similarly, Atlas-axis rotation was significantly higher in the TMD group (p < .001). However, no significant difference was found between mandible atlas rotations in the two groups (p = .546). The study also found a significant difference between the direction of rotation between the atlas and axis and the direction of mandible atlas rotation (p < .001) as well as between skull and atlas rotations and mandible-atlas rotations (p < .001).

CONCLUSION

Overall, the study suggests that there is a relationship between the skeletal structures of the cranio-cervico-mandibular system and TMD. Skull-atlas and atlas-axis rotations may play an important role in the aetiology of TMD in individuals with TMD. Therefore, it is important to evaluate rotations in the skull-atlas-axis region for the treatment of TMD.

Prevalence of temporomandibular disorders in clear aligner patients using orthodontic intermaxillary elastics assessed with diagnostic criteria for temporomandibular disorders (DC/TMD) axis II evaluation: A cross-sectional study

BACKGROUND

The objective of this investigation is to assess the relationship between the utilisation of orthodontic intermaxillary elastics and temporomandibular disorder (TMD) symptoms in clear aligner patients and to examine the correlation between the elastic usage time with the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD)-Axis II Evaluation Forms.

METHODS

This study was carried out on a total of 40 clear aligner patients using intermaxillary elastics in the experimental group and 30 clear aligner patients who did not use any intermaxillary elastics in the control group. The data were evaluated using the Mann-Whitney U, chi-square, Fisher's exact chi-square, and Fisher Freeman Halton exact chi-square tests.

RESULTS

The characteristic pain intensity, mastication, mobility, communication, global and PHQ-9 scores of the experimental group were significantly higher than those of the control group (p < .05). The characteristic pain intensity score, interference score and chronic pain grade score of patients using Class III elastics were statistically significantly higher than those of patients using Class II elastics (p < .05). Patients who used elastics for less than 6 months had statistically significantly higher PHQ-9 scores than those who used elastics for more than 6 months (p < .05).

CONCLUSIONS

Orthodontic treatment may affect occlusion, bite force and jaw movement, which may cause or worsen TMD symptoms, and the DC/TMD questionnaires can determine if orthodontic patients acquire TMD by assessing their psychosocial state and pain-related problems.

Surgical vs. Non-Surgical Management of Temporomandibular Joint Disorders: Clinical Outcomes

Background

Temporomandibular joint disorders (TMDs) encompass a range of clinical conditions affecting the temporomandibular joint (TMJ) and associated structures. Management approaches for TMDs vary and include both surgical and non-surgical interventions.

Materials and Methods

In this retrospective cohort study, medical records of 150 patients diagnosed with TMDs were reviewed. Patients were categorized into two groups: surgical intervention and non-surgical intervention. The surgical group underwent various surgical procedures, including arthroscopy, arthroplasty, and joint replacement, while the non-surgical group received conservative treatments such as physical therapy, pharmacotherapy, and occlusal splints. Pain levels, TMJ function, quality of life (QoL), and patient satisfaction were assessed at baseline and post-treatment (6 months and 1 year).

Results

At the 6-month follow-up, both groups experienced a significant reduction in pain scores (surgical group: 6.3 ± 1.2 to 2.4 ± 0.9, non-surgical group: 6.1 ± 1.1 to 3.2 ± 1.0). TMJ function improved in both groups (surgical group: 2.5 ± 0.8 to 4.8 ± 0.6, non-surgical group: 2.6 ± 0.7 to 4.2 ± 0.9). QoL scores increased (surgical group: 35.2 ± 4.6 to 50.3 ± 5.1, non-surgical group: 35.5 ± 4.2 to 45.7 ± 4.8), and patient satisfaction rates were high (surgical group: 92%, non-surgical group: 87%) at the 1-year follow-up.

Conclusion

Both surgical and non-surgical management approaches demonstrated significant improvements in pain relief, TMJ function, QoL, and patient satisfaction for individuals with TMDs.

Students' awareness of the bruxism causes, effects and therapies

Objectives

Bruxism is a repetitive activity of the masticatory muscles characterized by clenching or grinding teeth and/or mandibular stiffening. Bruxism manifests itself in two forms: during sleeping and waking. The etiology of bruxism is multifactorial. The treatment of bruxism is mainly based on making the patient aware of the presence of the condition. The aim of the study was to assess knowledge on the causes and the effects of bruxism among Polish students as well as the possible management.

Materials and methods

The anonymous online survey was conducted among students (aged between 18 and 25 years old) of universities across Poland, using the Google Forms platform. The survey contained questions concerning bruxism causes, effects and therapies. All variants of answers in these questions contained true information about bruxism.

Results

The study found significant differences in awareness of bruxism among genders in favor of females. The awareness of bruxism among population residing in cities and in villages was comparable (p > 0.05). However, the results should be taken with care due to limited number of students that participated in the study and uneven gender distribution among urban and village residents.

Conclusions

Within the limitations of the study it can be concluded that the knowledge of bruxism among Polish students is higher in comparison with the findings from the literature, as well as the superiority of women's awareness of bruxism over men. Future studies should be conducted on greater student population, with even distribution of participants among country areas and variety of universities.

Significance

The findings may indicate the need for further education of male young adults, on bruxism causes, possible effects and therapies to increase their awareness of bruxism and encourage early diagnosis and treatment.

Effects on Sleep Bruxism Activity of Three Different Oral Appliances: One Year Longitudinal Cohort Study

BACKGROUND

Different oral appliances (OAs) have been proposed to control sleep bruxism (SB) detrimental effects on the stomatognathic system.

OBJECTIVE

The aim of the study was to evaluate the effect of different OAs on SB activity and masticatory muscle activity (sMMA) measured by EMG.

METHODS

This longitudinal cohort study was conducted on 51 patients (21 M, 30 F, mean age 26,5 ± 3,5) suffering from SB diagnosed with a validated portable EMG-ECG holter and wearing different OAs: occlusal splints, functional appliance with metallic bites and clear aligners followed after 1 week, 1 month, 3 months, 6 months and 12 months from delivery. A control group of 16 non-treated SB patients (6 M, 10 F mean age 27,1 ± 1,4) was used as a reference. A multiple regression analysis was performed to estimate the differences between groups. The level of significance was set as P value <0,05.

RESULTS

Occlusal splint reduced sleep bruxism index after 1 week, 3, 6 and 12 months from delivery while functional appliance only after 12 months. Occlusal splints reduced general phasic contractions only in the first week and sleep bruxism-related phasic contractions at 1 week, 3 and 6 months after delivery with no significant reductions after 12 months. Patients wearing clear aligners showed a reduction in general tonic contractions after 6 and 12 months.

CONCLUSION

Resin and metal bites can reduce sleep bruxism index, while resin bites can reduce sleep bruxism-related phasic contractions. Clear aligners do not influence sleep bruxism index but can reduce tonic contractions.

Management of temporomandibular joint arthritis in children and adolescents: An introduction for orthodontists

Juvenile idiopathic arthritis (JIA) is the most common inflammatory rheumatic disease of childhood. JIA can affect any joint and the temporomandibular joint (TMJ) is one of the joints most frequently involved. TMJ arthritis impacts mandibular growth and development and can result in skeletal deformity (convex profile and facial asymmetry), and malocclusion. Furthermore, when TMJs are affected, patients may present with pain at joint and masticatory muscles and dysfunction with crepitus and limited jaw movement. This review aims to describe the role of orthodontists in the management of patients with JIA and TMJ involvement. This article is an overview of evidence for the diagnosis and treatment of patients with JIA and TMJ involvement. Screening for the orofacial manifestation of JIA is important for orthodontists to identify TMJ involvement and related dentofacial deformity. The treatment protocol of JIA with TMJ involvement requires an interdisciplinary collaboration including orthopaedic/orthodontic treatment and surgical interventions for the management of growth disturbances. Orthodontists are also involved in the management of orofacial signs and symptoms; behavioural therapy, physiotherapy and occlusal splints are the suggested treatments. Patients with TMJ arthritis require specific expertise from an interdisciplinary team with members knowledgeable in JIA care. Since disorders of mandibular growth often appear during childhood, the orthodontist could be the first clinician to see the patient and can play a crucial role in the diagnosis and management of JIA patients with TMJ involvement.

Biological and psychological factors affecting the sensory and jaw motor responses to orthodontic tooth movement

Orthodontic tooth movement (OTM) is associated with an inflammatory response, tooth pain (i.e. orthodontic pain) and changes in dental occlusion. Clinical realms and research evidence suggest that the sensory and jaw motor responses to OTM vary significantly among individuals. While some adjust well to orthodontic procedures, others may not and can experience significant pain or not adjust to occlusal changes. This is of concern, as clinicians cannot anticipate an individual's sensorimotor response to OTM. Converging evidence shows that some psychological states and traits significantly affect the sensorimotor response to OTM and may considerably affect an individual's adaptation to orthodontic or other dental procedures. We performed a topical review to synthesize the available knowledge about the behavioural mechanisms regulating the sensorimotor response to OTM, with the intent of informing orthodontic practitioners and researchers about specific psychological states and traits that should be considered while planning orthodontic treatment. We report on studies focusing on the role of anxiety, pain catastrophising, and somatosensory amplification (i.e. bodily hypervigilance), on sensory and jaw motor responses. Psychological states and traits can significantly affect sensory and jaw motor responses and a patient's adaptation to orthodontic procedures, although large interindividual variability exists. Clinicians can use validated instruments (checklists or questionnaires) to collect information about patients' psychological traits, which can assist in identifying those individuals who may not adjust well to orthodontic procedures. The information included in this manuscript also assists researchers investigating the effect of orthodontic procedures and or/appliances on orthodontic pain.

Comparative effectiveness of low-level laser therapy and transcutaneous electrical nerve stimulation in symptomatic Temporomandibular Disorders: A Randomised Control Trial

BACKGROUND

Myofascial pain is one of the most common facial region pains, presenting itself with various signs and symptoms like tenderness of masticatory muscles and difficulty in mouth opening. Considering its multifactorial aetiology various treatment modalities are present.

OBJECTIVE

The aim of this study is to compare the effectiveness of transcutaneous electrical nerve stimulation (TENS)and low-level laser therapy (LLLT) for the patients of temporomandibular disorders (TMDS).

METHODS

The study was conducted with 20 patients diagnosed with TMDS. Group A received LLLT at 660 nm, 6 J/point, two sessions/week for 4 weeks and group B received TENS at 2-250 Hz, two sessions/week for 4 weeks.

RESULTS

Pain Score decreased and mouth opening increased in both groups with time, however, the difference between the two groups was not statistically significant. Right and left lateral excursions showed improvement at different intervals in both groups. However, the LLLT group showed significant improvement.

CONCLUSION

Clinical trial showed improvement in visual analogue scale (VAS), maximum mouth opening (MMO) and lateral excursion in the different time intervals in both the groups with LLLT showed more improvement with lateral excursions movements.

Prevalence of bruxism in obstructive sleep apnea syndrome (OSAS) patients: A systematic review conducted according to PRISMA guidelines and the cochrane handbook for systematic reviews of interventions

BACKGROUND

Sleep bruxism (SB) and obstructive sleep apnea syndrome (OSAS) are two sleep-related conditions that have been associated with significantly conflicting results in literature. Understanding the prevalence of bruxism among OSA patients is crucial for identifying possible comorbidities and optimising treatment strategies.

OBJECTIVE

This systematic review aimed at analysing the prevalence of SB in OSAS sufferers and understanding the association between the two.

METHODS

Five online databases were searched for relevant articles in accordance with the PRISMA guidelines for conduction of systematic reviews. Studies reporting the prevalence of bruxism in OSAS patients and diagnosed through clinical assessments or polysomnography were included. Data extraction and quality assessment were performed independently by two reviewers. Methodological quality of the included studies was assessed using Risk of Bias In Non-randomised Studies of Interventions (ROBINS-I).

RESULTS

A thorough search of literature yielded only two studies were eligible for this review. SB was found to be significantly present in the OSAS group. Despite methodological variations, the majority of studies reported higher rates of bruxism in OSAS patients compared to the general population or control groups.

CONCLUSION

The results of this systematic review point to a significant association between bruxism and obstructive sleep apnea. Further research is required to determine a more precise prevalence rate and investigate the potential therapeutic implications of the bruxism-OSAS association that uses a standardised assessment techniques and larger sample sizes.

Online Bruxism-related information: Can people understand what they read? A Cross-Sectional Study

BACKGROUND

Bruxism patients often access the web to search for information. Unfortunately, the low text readability of online material and the limited medical literacy in the general population may prevent patients' understanding of health information.

OBJECTIVE(S)

We aimed to assess the home page's readability of the top 10 patients-oriented bruxism-related websites and the educational level required to approach them.

METHODS

Using the word bruxism in the "no country redirect" extension of Google Chrome browser (www.google.com/ncr), we identified the first 10 patient-oriented English language websites. The readability of the material was determined using six commonly recommended readability tests (1): Gunning Fog Index (GFI), Coleman Liau Index (CLI), Automated Readability Index (ARI) Simple Measure of Gobbledygook (SMOG), Flesch Kincald Grade Level (FKGL), Flesh Reasing Ease (FRE).

RESULTS

The USA National Institutes of Health requirements, which call for websites to be readable at a 6th to 7th-grade level, were not followed by any of the most popular websites.

CONCLUSION

The average consumer frequently finds the health information on the Internet to be too complex to understand, which can lead to misinterpretation, a delay in diagnosis, and poorer health consequences.

Prevalence of Temporomandibular Disorders in Orthognathic Surgery patients: A systematic review conducted according to PRISMA guidelines and the Cochrane Handbook for Systematic Reviews of Interventions

BACKGROUND

Orthognathic surgery is done to treat a variety of dentofacial abnormalities, but a wide gap still remains on how it can result in temporomandibular joint dysfunction (TMD). The primary goal of this review was to assess the effects of various orthognathic surgical techniques on the emergence or exacerbation of TMJ dysfunction.

METHODS

A comprehensive search was conducted across several databases using Boolean operators and MeSH keywords related to temporomandibular joint disorders (TMDs) and orthognathic surgical interventions, with no limitation on the year of publication. Two independent reviewers screened the identified studies based on predetermined inclusion and exclusion criteria, followed by a risk of bias assessment using a standardised tool.

RESULTS

Five articles were considered for inclusion in this review. A greater number of females opted for surgical options than their male cohorts. Three studies were of prospective design, 1 of retrospective and 1 of observational type. Mobility on lateral excursion, tenderness on palpation, arthralgia and popping sounds were the TMD characteristics that showed significant differences. Overall, orthognathic surgical intervention did not show an increase in TMD signs and symptoms as compared to nonsurgical counterparts.

CONCLUSION

Though orthognathic surgery reported greater cases of some TMD symptoms and signs as compared to the nonsurgical cohorts in four studies, the conclusive evidence is debatable. Further studies are recommended with a longer follow-up period and greater sample size to determine the impact of orthognathic surgery on TMJ.

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

OBJECTIVE

This study evaluated the dimensional and positional osseous temporomandibular joint features in normodivergent facial patterns with and without temporomandibular disorders.

METHODS

A total of 165 adult patients were divided into two groups: group 1 (n = 79 patients; 158 joints): temporomandibular disorders patients and group 2 (n = 86 patients; 172 joints): non-temporomandibular disorders patients. Three-dimensional positional and dimensional temporomandibular joint characteristics, including glenoid fossa, mandibular condyles, and joint spaces, were assessed by cone beam computed tomography.

RESULTS

The glenoid fossa positions in the three orthogonal planes and height showed statistical significance between the two studied groups. The temporomandibular disorders patients showed higher horizontal and vertical condyle inclinations while anteroposterior inclination was less, and the condyle was positioned more superior, anterior, and lateral in the glenoid fossa. The condyle width and length showed no significance between the two groups, while condyle height was smaller in temporomandibular disorders patients. Anterior and medial joint spaces increased while the superior and posterior joint spaces reduced in temporomandibular disorders patients.

CONCLUSION

There were significant differences between the patients with and without temporomandibular joint disorders in terms of mandibular fossa positions and height as well as condylar positions and inclinations in horizontal and vertical planes together with reduced condylar height and reduced posterior and superior joint spaces in the temporomandibular disorders patients.

CLINICAL RELEVANCE

The temporomandibular disorder is a multifactorial disorder in which one of these factors is the dimensional and positional characteristics of the temporomandibular joints; including or excluding this factor requires a comprehensive three-dimensional investigation of patients with TMD compared to the normal group under the condition that the facial pattern is average as a confounding factor.

Knowledge and Attitudes regarding Temporomandibular Disorders among Postgraduate Dental Students and Practicing Dentists in Western China: A Questionnaire-Based Observational Investigation

Background

It is necessary for dental students and dentists to apply their temporomandibular disorders (TMDs)-related knowledge to clinical practice. The current study aimed to evaluate the knowledge and awareness of postgraduate dental students and practicing dentists regarding etiology, diagnosis, and treatment of TMD in western China and thus provide suggestions on TMD curricula design to get postgraduate students and dentists better prepared for TMD diagnosis and treatment.

Methods

This observational and descriptive cross-sectional study was conducted among postgraduate students and practicing dentists in western China. Twenty-five reorganized knowledge questions in four domains were selected from the published literature and were evaluated with answer options from "strongly agree" to "strongly disagree," and "I don't know." "Consensus" is defined as more than 50% of respondents in a group agree or disagree with a statement. Chi-square tests were performed for comparisons between the two groups.

Results

A total of 132 postgraduate dental students and 123 dentists completed the questionnaire. Around 75% of postgraduate students and 85% of dentists claimed that they have never participated in systematic training in TMD. Nine statements in etiology, diagnosis, treatment, and prognosis of TMD had different consensus between the two groups. And the dentist group tended to agree more with 12 statements in the questionnaire.

Conclusions

The majority of Chinese dentists and dental students have not taken any TMD courses and possess limited knowledge of TMD. Curriculum reform for predoctoral education, postgraduate education, and continuing education is needed to augment knowledge and skills for TMD diagnosis and treatment.

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.

Association of Serum Vitamin D Level with Temporomandibular Disorder Incidence: A Retrospective, Multi-Center Cohort Study Using Six Hospital Databases

The relationship between serum vitamin D levels and temporomandibular disorders (TMDs) remains unclear. Therefore, this study aimed to investigate the association between serum 25-hydroxyvitamin D (25[OH]D) levels and TMD incidence using large-scale health data. Clinical data from the electronic health records of six secondary or tertiary hospitals in Korea were used to evaluate the relationship between serum 25(OH)D levels and TMD incidence. The data were converted to the Observational Medical Outcomes Partnership Common Data Model. A cohort study was designed using the Cox proportional hazards model to examine the hazard ratio (HR) of TMD development after propensity score matching (PSM). An aggregate meta-analysis of the HR was subsequently performed. After 1:4 PSM, a target group with deficient 25(OH)D levels (<20 ng/mL) (N = 34,560) and comparator group with non-deficient 25(OH)D levels (≥20 ng/mL) (N = 47,359) were pooled from six hospital databases. HR meta-analysis demonstrated a significant association between deficient 25(OH)D levels and TMD incidence (pooled HR: 1.50; 95% confidence interval: 1.07-2.12). In conclusion, deficient 25(OH)D levels were found to be associated with an increased TMD risk. Therefore, vitamin D deficiency is a potential risk factor for TMD development.

The Role of Supraerupted and Distoverted Maxillary Third Molars in the Treatment of Temporomandibular Disorder: A Randomised Controlled Trial

Objective Temporomandibular disorder (TMD) is a multifactorial disease that is classified into muscular and joint disorders. The etiology of TMD is unknown but it is related to various factors such as bruxism, uncorrected high dental restorations, and occlusal prematurities. This study aims to provide treatment modalities for TMD patients with supraerupted and/or distoverted maxillary third molars that have premature contact with the opposing arch. Methods A total of 430 subjects diagnosed with TMD were included in the study and randomized into study and control groups based on their treatment needs. A detailed case history was taken, and findings of intra and extra oral examination were recorded along with other investigations such as study model analysis, orthopantomogram (OPG), cone-beam computed tomography (CBCT), and MRI. The multiphase treatment included counseling in phase I, extraction in phase II (only for the study group), and oral appliance in the third phase. The final phase involved the restoration of edentulous areas or reduced vertical dimension. Results Extraction of supraerupted and/or distoverted maxillary third molars in the study group during phase II showed a 96% reduction in TMD when compared to the control group who did not undergo extraction. Conclusion TMD is a repetitive motion disorder, and the success of treatment relies on the elimination of causative factors, the type of appliance used, and the establishment of ideal occlusion. This study suggests that the extraction of supraerupted and/or distoverted maxillary third molars is a prerequisite for treating TMD patients.

Prevalence of temporomandibular disorders in adult obstructive sleep apnoea patients: A cross-sectional controlled study

BACKGROUND

Obstructive sleep apnoea (OSA) is characterised by partial or complete obstruction of the upper airways during sleep and it has been associated with temporomandibular disorders (TMDs) on the basis of several pathophysiological hypotheses.

OBJECTIVES

To assess the prevalence of TMDs in a population of patients affected by OSA compared to a control group of subjects not affected by OSA.

METHODS

A cross-sectional controlled study was conducted on a group subjects studied by polygraphy (PG) at the snoring section of the ENT department, Sant'Orsola-Malpighi Hospital - University of Bologna. Patients who received a diagnosis of OSA were included in the study group and subjects with a negative PG diagnosis for Sleep Disordered Breathing and PG respiratory pattern that did not suggest the occurrence of sleep disorders were enrolled in the control group. Both the subjects included in the study group and the control group underwent an examination following the Diagnostic Criteria for Temporomandibular Disorders Axis I and II.

RESULTS

Forty-three OSA patients (29 M, 16 F, mean age 52.26 ± 11.40) and 43 healthy controls (25 M, 18 F, mean age 49.95 ± 7.59) were included in the study. No significant differences were found between groups in demographic data. TMD prevalence and Axis II results did not differ between groups.

CONCLUSIONS

This paper does not highlight a higher prevalence of TMDs in adults with OSA compared to healthy controls. Further high-quality studies are needed to confirm the results and to give possible pathophysiological explanations, providing reliable evidence.

Temporomandibular Disorders: Implications in Restorative Dentistry and Orthodontics

Over the past several decades, the science of restorative/reconstructive dentistry and orthodontics has evolved tremendously, following sound principles passed down from robust literature and scientific rationale. These principles have been solid and instrumental in enhancing dentistry, from a single tooth restoration to complex full-mouth rehabilitations. However, it must be noted that some of the principles and philosophies followed over these decades have been questioned based on the advances in science, technology, and evidence-based medicine. The scenario became complex when clinicians were faced with the question of guidance for optimum joint and muscle health as related to restorative dentistry and orthodontics.

Numerical investigation of the biomechanical effects of orthodontic intermaxillary elastics on the temporomandibular joint

Temporomandibular joint disorder (TMD) often coincides with malocclusion, and in some cases TMDs are reported after orthodontic treatment. Intermaxillary elastics (also known as orthodontic elastics, OE) are a common way to apply force during orthodontic treatment, and they might cause mechanical effects on the temporomandibular joint (TMJ), thereby lead to joint remodeling. It is still a controversial topic whether the adapted remodeling of the TMJ or of the alveolar bone is the main cause for the alteration of occlusion after treatment with OEs. It was the aim of this study to analyze whether variations of OEs would develop harmful effects on the healthy TMJ. A TMJ model with a masticatory system based on Hill-type muscle actuators was established. Mouth opening and closure with and without OEs were simulated, and maximum principal stresses in the disc and condylar cartilage as well as the displacement of the mandible were analyzed. We found no considerably difference in the mandibular movement without and with symmetrical OEs during mouth opening and closing. At full mouth opening, stresses in the disc and condylar cartilage of some models with OEs were much smaller than without OEs, but we did not find consistency in the results from the left and right sides of the same model (e.g. the lowest compressive stress on the left side of disc from the model with Class II OEs is much smaller than without OEs, -17.3 MPa compared with -28.2, while on the right side, there was no obvious difference). Hence, we could not conclude that OEs would develop deleterious effects on the healthy TMJ.

Relationships between tooth wear, bruxism and temporomandibular disorders

This article will provide an overview of the diagnosis of common temporomandibular disorders (TMDs) and bruxism, along with their relevance in management of tooth wear. When assessing and managing a tooth wear case, the teeth should not be considered in isolation, but as part of the articulatory system, which has three inter-related elements: the teeth, the temporomandibular joints and the masticatory muscles. The presence/absence of bruxism and TMD are highly relevant, although there may not be a causal relationship between these. A consideration of TMD and bruxism, together with the potential impact these may have on the patient during and after any management of tooth wear, will form part of patient education and the informed consent process.

Vitamin D3 Metabolism and Its Role in Temporomandibular Joint Osteoarthritis and Autoimmune Thyroid Diseases

The aim of this review was to present the metabolism of vitamin D3, as well as to discuss the role of vitamin D3 in bone metabolism, temporomandibular joint osteoarthritis (TMJ OA), and autoimmune thyroid diseases (AITD) on the basis of the literature. Vitamin D3 plays a significant role in human health, as it affects the calcium-phosphate balance and regulates the bone metabolism. Calcitriol impresses the pleiotropic effect on human biology and metabolism. Its modulative function upon the immune system is based on the reduction of Th1 cell activity and increased immunotolerance. Vitamin D3 deficiency may lead to an imbalance in the relationship between Th1/Th17 and Th2, Th17/Th reg, and is considered by some authors as one of the possible backgrounds of autoimmune thyroid diseases (AITD), e.g., Hashimoto's thyroiditis or Graves' disease. Moreover, vitamin D3, through its direct and indirect influence on bones and joints, may also play an important role in the development and progression of degenerative joint diseases, including temporomandibular joint osteoarthritis. Further randomized, double blind studies are needed to unequivocally confirm the relationship between vitamin D3 and abovementioned diseases and to answer the question concerning whether vitamin D3 supplementation may be used in the prevention and/or treatment of either AITD or OA diseases.

Dimensional and Positional Characteristics of the Temporomandibular Joint of Skeletal Class II Malocclusion with and without Temporomandibular Disorders

AIM

This study sought to evaluate dimensional and positional temporomandibular joint (TMJ) features in three-dimensions in skeletal class II malocclusion with and without temporomandibular disorders (TMDs).

MATERIALS AND METHODS

A total of 91 (182 joints) adult patients were divided into the following two groups: (1) Group I - TMD (n = 56; 112 joints) and (2) group II - non-TMD (n = 35; 70 joints). Dimensional and positional TMJ characteristics including glenoid fossae, mandibular condyles, and joint spaces were assessed using cone-beam computed tomography (CBCT).

RESULTS

The mandibular fossa in the TMD group was significantly more lateral than in the non-TMD group, and the mandibular fossa anterior wall inclination to the horizontal plane showed a significantly more vertically inclined wall in the TMD group compared to the non-TMD group. Significantly vertical mandibular condylar changes in the form of less vertical inclination, more vertical position, and lower vertical dimension (height) in addition to more upward position within the joint space were found. The TMD group showed significantly decreased superior and posterior joint spaces in addition to significantly increased medial joint spaces.

CONCLUSION

Patients with TMDs are associated with laterally positioned mandibular fossa with the more vertically inclined anterior wall. They are characterized by vertical mandibular condylar changes in the form of less vertical inclination, more vertical position, and lower vertical dimension (height) in addition to more upward positioning within the joint space is accompanied by a decrease in superior and posterior and an increase in medial joint spaces.

CLINICAL SIGNIFICANCE

The TMJ characteristics of skeletal class II make it more susceptible to TMDs and any orthodontic and/or surgical interventions in a direction possibly change these characteristics are to be considered.

Are acupuncture and dry needling effective in the management of masticatory muscle pain: A network meta‐analysis of randomised clinical trials

BACKGROUND

Several studies have shown that both acupuncture and dry needling are effective in the treatment of musculoskeletal pains. Therefore, the aim of this network meta-analysis (NMA) was to investigate the treatment outcome of acupuncture and dry-needling for masticatory muscle pain (TMD-M) and to compare with active and inactive placebo.

MATERIAL AND METHOD

An electronic search was performed to identify randomised controlled trials (RCTs) published until September 2019, comparing dry-needling, acupuncture, and inactive as well as active placebo in patients with TMD-M. Outcome variables were post-treatment pain intensity, pressure pain threshold (PPT), and maximum mouth opening (MMO). The quality of evidence was rated according to Cochrane's tool for assessing the risk of bias. Mean difference was used to analyse via frequentist NMA using STATA-software.

RESULTS

Both NMA and direct pairwise meta-analysis have shown that there was no difference between active treatment with either acupuncture or dry-needling when compared to active and inactive placebo in patients with TMD-M with respect to pain intensity, and PPT (p > .05). However, there was a significant increase in MMO following dry-needling when compared to the placebo (very low-quality evidence).

CONCLUSION

Despite the short-term positive effect of MMO by dry-needling, this NMA could not show any pain-reducing effect in patients with TMD-M by acupuncture or dry-needling when compared to an active or inactive placebo. Taken together, this NMA indicates that it is the placebo effect that accounts for the majority of the treatment effect of TMD-M, rather than a real therapeutic effect of acupuncture/dry-needling.

Multi-disciplinary treatment of maxillofacial skeletal deformities by orthognathic surgery combined with periodontal phenotype modification: A case report

BACKGROUND

Maxillofacial deformities are skeletal discrepancies that cause occlusal, functional, and esthetic problems, and are managed by multi-disciplinary treatment, including careful orthodontic, surgical, and periodontal evaluations. However, thin periodontal phenotype is often overlooked although it affects the therapeutic outcome. Gingival augmentation and periodontal accelerated osteogenic orthodontics (PAOO) can effectively modify the periodontal phenotype and improve treatment outcome. We describe the multi-disciplinary approaches used to manage a case of skeletal Class III malocclusion and facial asymmetry, with thin periodontal phenotype limiting the correction of deformity.

CASE SUMMARY

A patient with facial asymmetry and weakness in chewing had been treated with orthodontic camouflage, but the treatment outcome was not satisfactory. After examination, gingiva augmentation and PAOO were performed to increase the volume of both the gingiva and the alveolar bone to allow further tooth movement. After orthodontic decompensation, double-jaw surgery was performed to reposition the maxilla-mandibular complex. Finally, implant placement and chin molding were performed to restore the dentition and to improve the skeletal profile. The appearance and function were significantly improved, and the periodontal tissue remained healthy and stable.

CONCLUSION

In patients with dentofacial deformities and a thin periodontal phenotype, multi-disciplinary treatment that includes PAOO could be effective, and could improve both the quality and safety of orthodontic-orthognathic therapy.

Impacts of using orthodontic appliances on the quality of life of children and adolescents: systematic review and meta-analysis

BACKGROUND

Although there are previous systematic reviews about the oral health-related quality of life (OHRQoL) impact among children and adolescents after orthodontics treatment, there is no definition for the magnitude of these impacts during the therapy.

OBJECTIVE

To systematically analyse the literature on changes in the quality of life of children and adolescents during orthodontic treatment.

LIMITATIONS

Almost all the studies included in this review are non-randomized clinical trials, which are susceptible to several biases that affect the certainty of evidence obtained, especially by confounding factors and the lack of a control group.

CONCLUSIONS AND IMPLICATIONS

Based on very low certainty of evidence, wearing appliances does not seem to have a significant negative impact during the first year of orthodontic treatment. However, the meta-analytic results suggest that functional limitations in the first 3 months of treatment can be slightly more critical for the impact on the oral health quality of life and consequent patient adherence to treatment.

FUNDING

This study was financed by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brazil (CAPES), Conselho Nacional de Desenvolvimento Científico e Tecnológico - Brazil (CNPq), and Fundação de Amparo à Pesquisa do Estado de Minas Gerais - Brazil (FAPEMIG).

REGISTRATION

CRD42021234407.

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.

Craniovertebral and Craniomandibular Changes in Patients with Temporomandibular Joint Disorders after Physiotherapy Combined with Occlusal Splint Therapy: A Prospective Case Control Study

Background and Objectives: The aim of the study was to assess the craniovertebral and craniomandibular changes in patients diagnosed with temporomandibular joint disorders (TMD) after physiotherapy combined with occlusal splint therapy. Materials and Methods: There were forty patients (32 females, 80%), diagnosed with TMD, included into the study group. After the initial series of physiotherapy, patients received maxillary occlusal splints to be worn day and night. Participants continued physiotherapy simultaneously with occlusal splint therapy for 6 months. Lateral cephalograms taken in natural head position before and after the end of the therapy were used for measurements. The control group consisted of 15 healthy participants (12 females, 80%), who had taken lateral cephalograms twice, and did not receive any type of occlusal treatment nor physiotherapy in the meantime. Results: Occlusal splint therapy and physiotherapy combined together significantly affected: the vertical position of the mandible (significant increase, p < 0.0001), the sagittal position of mandible (significant decrease, p = 0.0065), as well as the width of the functional space between C1 and C2 (significant decrease, p = 0.0042). Moreover, the cervical lordosis was restored after the end of the treatment (p < 0.0001). Conclusions: Cooperation of physiotherapists with dental practitioners is necessary in the treatment of patients with TMD, including temporomandibular joint osteoarthritis.

Computer-Aided Autogenous Coronoid Process Graft Combined With Median and Unilateral Sagittal Split Osteotomy for Late Reconstruction of Condylar Fracture and Occlusion after Trauma

PURPOSE

This study proposes a high-precision surgical technique that combines both computer-aided design/computer-aided manufacturing (CAD/CAM) and the screw-track transfer technique for condylar and occlusal reconstruction.

MATERIALS AND METHODS

A 43-year-old male patient with facial asymmetry, limited mouth opening, and malocclusion underwent condylar and occlusal reconstruction surgery. An autogenous coronoid process graft was performed by combining CAD/CAM and the screw-track transfer technique.

RESULTS

The surgical plan was transformed successfully from preoperative virtual surgical planning to actual surgery; this was confirmed by merging the postoperative computed tomography images with the preoperative three-dimensional surgical design. The patient recovered well and had better occlusion and facial symmetry, as well as an increased degree of mouth opening post-surgery. No complications were observed.

CONCLUSIONS

CAD/CAM combined with the screw-track transfer technique is a precise and feasible method that can be applied to autogenous coronoid process grafts. This approach can be used to reconstruct the condylar process and achieve a good occlusal relationship.

Patients' perceptions on temporomandibular disorder treatment with hydrostatic oral splints - a pilot study

Objective

To evaluate temporomandibular disorder (TMD) treatment with a prefabricated, hydrostatic oral splint (HOS) based on self-reported patient’s symptoms using a standardized questionnaire.

Methods

Two hundred fifty-eight questionnaires from patients diagnosed with TMD and subsequently treated with HOS were collected from two independent private practices. Based on patient’s comfort the questionnaire recorded TMD symptoms and symptom regression. Descriptive and comparative statistics was carried out using SPSS.

Results

A total of 221 questionnaires were analyzed. Patients reported TMD symptoms such as pain (93.2%), TMJ clicking (66.1%), headache (25.8%), cervical spine disorders (23.5%), restricted mouth opening (22.6%) and tinnitus (11.8%). For most symptoms, improvement was reported mostly after two weeks, except for tinnitus, where positive effects were usually reported after four weeks.

Conclusion

HOS seem to be effective for immediate treatment of pain and other TMD symptoms. Based on the available data, a treatment period of four weeks can be recommended.

The Role of Maxillofacial Structure on Condylar Displacement in Maximum Intercuspation and Centric Relation

Purpose

This study is aimed at evaluating the impact of the craniofacial structure and occlusal conditions on the position of the articular heads of the mandibular condyles in the maximum intercuspal position (MIP) and comparing the centric relation (CR) and MIP of the mandibular condyles prior to orthodontic treatment.

Methods

The studied group consisted of 33 women and 15 men (median age of 17.75 years). Contact points of opposing teeth in the MIP were assessed by hand-held casts. Condylar displacement (CD) in three spatial planes on both sides was measured on models mounted in an articulator using a mandibular position indicator (MPI). Patients were divided into groups according to craniofacial structures (vertical and horizontal growth directions). The Mann-Whitney, Kruskal-Wallis, post hoc Dwass-Steel-Critchlow-Fligner, and Pearson's χ² independence tests as well as Spearman's nonparametric correlations were used in the statistical analyses.

Results

Within the limitations of this study, no statistically significant correlation of CD with certain cephalometric measurements from a lateral cephalometric radiograph (ANB, SN-ML, and SGo/NMe) was observed. Correlation, however, was found between condylar displacement in the transverse axis and the mandibular plane angle SN-ML (p = 0.033) and also between condylar displacement in the anteroposterior axis and a midline shift of the mandible (p = 0.041). The results revealed a relationship between Angle's classification of molar position on the right side and anteroposterior CD values (p = 0.006).

Conclusions

Cephalometric measurements cannot be used to predict CD at the level of the condyles. Analysis of occlusal conditions of models mounted in an articulator is desirable for patients with Angle's class I and lower jaw asymmetry.

Role of the general dental practitioner in managing the risks of orthodontic treatment

The aim of this article is to outline the potential risks in orthodontic treatment and the general dental practitioner's role in reducing and managing such risks. The success of orthodontic treatment largely depends on patient understanding of the risk/benefit implications of the orthodontic treatment and all of the potential consequences involved in such treatment. A perfect blend of good case selection, sound clinical judgement and, more importantly, a patient's clear understanding of the potential risks involved and the treatment implications help minimise and manage potential hazards that occur during the course of the treatment.

Nonsurgical treatment of class III malocclusion with temporomandibular disorder comorbidity: A clinical report

The treatment of a 57-year-old woman with combined skeletal and pseudo-class III malocclusion who was also suffering from chronic myofascial orofacial pain is described. The challenge was to treat the patient's malocclusion while simultaneously managing the temporomandibular disorder. After a successful 3-month occlusal device therapy, which substantially reduced the patient's discomfort, a nonsurgical therapy by using complete-mouth fixed restorations was planned. The treatment was first tested by using printed interim restorations before monolithic zirconia restorations were provided. Stable occlusion and a pain-free outcome were observed at the 3-month follow-up.

Temporomandibular disorders in patients with inherited coagulation disorders: A clinical study

INTRODUCTION

One of the most common problems in patients with inherited coagulation disorders, especially hemophilia, is joint problems. This study aims to investigate whether temporomandibular joint (TMJ) is affected in patients with hemophilia or other coagulation factor disorders.

MATERIAL & METHODS

In this study, a patient group and a control group were formed. The patient group consisted of 44 individuals with hemophilia or other coagulation disorders (von Willebrand disease and rare factor deficiencies) and the control group consisted of 45 healthy individuals. In both groups, TMJ health was evaluated through a questionnaire and clinical examination.

RESULTS

The prevalence of signs and symptoms of temporomandibular disorders (TMD) that we evaluated was higher in the patient group than in the healthy individuals. Pain in the jaw, temple, in the ear or in front of the ear; pain in the jaw, temple, ear or front of the ear by opening the mouth or moving the jaw forward/sideways; closed locking (subjective); jaw joint noises (subjective) and TMJ noises during open & close movements on the right side in clinical examination were statistically significantly higher in the patient group than in the control group.

DISCUSSION

There are very limited studies on temporomandibular joint health in patients with coagulation factor deficiency. In this study, it was observed that patients with inherited coagulation disorders, especially hemophilia, were more likely to develop TMD than healthy individuals. This situation was thought to be due to the increased susceptibility to TMJ bleeding in patients with coagulation factor deficiency.

Centric relation critically revisited-What are the clinical implications?

PURPOSE OF THE ARTICLE

Centric relation is a dental term that has undergone many alterations over the years, which in turn have led to significant clinical controversies. These continuing changes in the meaning of the term CR have not only led to confusion, but they also have resulted in a variety of unnecessary diagnostic and therapeutic procedures. Analysis of the dental literature reveals ongoing misunderstanding and disagreement regarding that term among both clinicians and academic dentists.

MATERIALS AND METHODS

A search of the PubMed database was performed with the following search terms: "centric relation", "masticatory muscles", "maxillomandibular relationship" and "condylar position." Relevant literature from the past 70 years until the present day was meticulously scrutinised.

RESULTS

As expected, the literature review on the topic of CR revealed a problematic pattern of changing definitions and clinical disagreements, all of which have had a significant impact on the practice of dentistry.

CONCLUSION

There are semantic, conceptual and practical reasons for concluding that the term 'centric relation' is flawed. Those flaws have a significant impact on dental practice. Based on our analysis, argumentation is provided to conclude that the term 'centric relation' should be abandoned. Instead, it appears that every individual has a unique temporomandibular joint relationship which cannot be described by any singular term. In healthy dentate patients, this relationship is determined by the maximum intercuspation of the teeth and should therefore be considered as biologically acceptable.