Extraoral Versus Intraoral Botulinum Toxin Type A Injection for Management of Temporomandibular Joint Disc Displacement With Reduction:

Ultrasonographic assessment of the lateral pterygoid muscle for BoNT-A injection

The upper head of the lateral pterygoid muscle (LPM) is known to insert into the capsule of the temporomandibular joint and articular disc, and therefore its relationship with temporomandibular disorders (TMD) has been consistently suggested. The aim of the study was to determine the anatomical features of the LPM using ultrasonographic (US) imaging. Around 120 hemifaces from 60 healthy Korean volunteers were included in this study. US images were taken with the subject's mouth 2 cm open. The transducer was placed at a position where the infratemporal fossa could be observed through the mandibular notch, and its position was recorded. The locations of the coronoid process (CorP), lateral margin of the condylar process (ConP), and midpoint of CorP and ConP (MP) were measured with reference to the ala-tragus line. The thicknesses of the skin and subcutaneous tissue, the masseter muscle, the temporalis muscle, and the depth of the LPM were measured at the MP. The masseter muscle, temporalis muscle, and LPM were observed in all cases and located in order from superficial to deep. The MP was located 39.6 ± 3.3 mm anterior and 7.8 ± 1.6 mm inferior to the tragus. The thicknesses of the skin and subcutaneous tissue, the masseter muscle, the temporalis muscle, and the depth of the LPM at the MP were 9.7 ± 1.0, 10.3 ± 1.3, 10.9 ± 1.6, and 30.9 ± 1.9 mm, respectively. The information reported in this study may be useful for determining the location of the LPM and adjacent anatomical structures in TMD patients and provide accurate and safe injection guidelines.

Lateral pterygoid muscle ultrasound-guided injection: A technical note

BACKGROUND

Temporomandibular disorders (TMDs) are a frequent cause of orofacial pain, causing functional disability and a negative impact on quality of life. Botulinum toxin (BTX-A) injection in lateral pterygoid muscle (LPM) is one of the treatment modalities proposed, but the blind puncture guided by EMG carries a risk of vascular puncture or diffusion of the toxin to nearby muscles. We describe an ultrasound-guided approach and evaluate the spread of the injection in a fresh human cadaver.

METHODS

A fresh human cadaver was injected. An out-of-plane approach was performed using a convex probe, injecting 1.0 ml of 0.25% methylene blue dye into the LPM. After, a dissection was performed to isolate the lateral pterygoid muscle and assess the spread of the dye.

RESULTS

Ultrasound-guided injection allowed to visualize in real-time the spread of the dye within the LPM. The deep and superficial muscles nearby to LPM were not stained by the dye, but upper and lower head of LPM was heavily stained.

CONCLUSION

Ultrasound-guided approach for the injection of BTX-A into the LPM could be considered a successful and safe treatment for myofascial pain related to TMD. Therefore, further clinical studies are needed to study the reproducibility of ultrasound guided LPM injection and to evaluate the clinical results.

IncobotulinumtoxinA in refractory temporomandibular disorder due to disk dislocation: A prospective study

INTRODUCTION

Temporomandibular disorders (TMD) may include conditions involving the temporomandibular joint and/or masticatory muscles. Approximately 20 % of patients are refractory to first-line therapies. This study aims to evaluate the effects and safety of incobotulinumtoxinA in the treatment of refractory TMD due to disk dislocation.

MATERIAL AND METHODS

A quasi-experimental one-arm prospective study was conducted. Target population included individuals with a diagnosis of TMD due to disk dislocation. Patients were treated with electromyography or ultrasound guided injection of incobotulinumtoxinA in the masticatory muscles (20 U into each masseter and pterygoideus lateralis). Pain was assessed using the pain numerical rating scale, maximum unassisted mouth opening was measured in mm, and adverse events were registered at baseline, week 4, week 12 and week 24 post-treatment. Statistical analysis used the Wilcoxon test for the comparison of paired samples and the Mann-Whitney U test for independent samples, considering a p-value ≤ 0.05 as significant.

RESULTS

51 patients with 75 painful temporomandibular joints due to disk dislocation (38 with reduction and 37 without) were included. A significant reduction in pain from a pre-treatment mean of 6.08/10 to a post-treatment mean of 2.04/10 (week 4), 3.18/10 (week 12), and 3.65/10 (week 24) was observed (p < 0.001). A significant decrease in maximum unassisted mouth opening from a pre-treatment mean of 36.45 mm to a post-treatment mean of 32.29 mm at week 4 was observed (p < 0.001).

DISCUSSION

Botulinum toxin injection of the masticatory muscles is safe and seems equally effective in reducing pain in patients with refractory TMD due to disk dislocation.

Conservative versus Invasive Approaches in Temporomandibular Disc Displacement: A Systematic Review of Randomized Controlled Clinical Trials

BACKGROUND

Temporomandibular disorders (TMDs) frequently cause orofacial pain and dysfunction, with treatment options spanning from conservative therapies to invasive surgical procedures. The aim of this systematic review was to analyze and compare the efficacy and safety profiles of conservative, minimally invasive interventions and surgical procedures in patients diagnosed with TMDs and disc displacement.

METHODS

Following PRISMA recommendations, PubMed, Scopus, and Web of Science databases were searched for randomized clinical trials (RCT). Data were synthesized in a table and evaluated through the Cochrane risk of bias 2 (RoB 2) tool.

RESULTS

Thirty-eight RCTs, most with moderate RoB, were selected. Conservative approaches, including physical therapy and occlusal devices, led to an improvement in symptoms and function. Pharmacological treatments demonstrated effectiveness in reducing pain and improving function; however, they can have undesirable side effects. Minimally invasive and invasive treatments also demonstrated efficacy, although most trials did not show their superiority to conservative treatments.

CONCLUSION

The primary approach to TMDs should be a conservative, multimodal treatment plan tailored to patient complaints and characteristics. Treatment goals should focus on symptom control and functional recovery. Surgical treatment should be reserved for cases with a precise diagnosis and a clear etiology.

Analysis of the Use of Sample Size and Effect Size Calculations in a Temporomandibular Disorders Randomised Controlled Trial-Short Narrative Review

BACKGROUND/OBJECTIVES

Temporomandibular disorder (TMD) is the term used to describe a pathology (dysfunction and pain) in the masticatory muscles and temporomandibular joint (TMJ). There is an apparent upward trend in the publication of dental research and a need to continually improve the quality of research. Therefore, this study was conducted to analyse the use of sample size and effect size calculations in a TMD randomised controlled trial.

METHODS

The period was restricted to the full 5 years, i.e., papers published in 2019, 2020, 2021, 2022, and 2023. The filter article type-"Randomized Controlled Trial" was used. The studies were graded on a two-level scale: 0-1. In the case of 1, sample size (SS) and effect size (ES) were calculated.

RESULTS

In the entire study sample, SS was used in 58% of studies, while ES was used in 15% of studies.

CONCLUSIONS

Quality should improve as research increases. One factor that influences quality is the level of statistics. SS and ES calculations provide a basis for understanding the results obtained by the authors. Access to formulas, online calculators and software facilitates these analyses. High-quality trials provide a solid foundation for medical progress, fostering the development of personalized therapies that provide more precise and effective treatment and increase patients' chances of recovery. Improving the quality of TMD research, and medical research in general, helps to increase public confidence in medical advances and raises the standard of patient care.

Anatomical factors influencing temporomandibular joint clicking in young adults: temporomandibular joint structure disorder or lateral pterygoid muscle dysfunction?

Objective: This study aimed to investigate the selected anatomical factors that can potentially influence temporomandibular joint (TMJ) clicking in young adults by assessing TMJ structures and lateral pterygoid muscle (LPM) function using magnetic resonance imaging (MRI). Methods: The patients were divided into four groups: the healthy control group; the clicking on mouth opening group; the clicking on mouth closing group; and the clicking on mouth opening and closing group. Additionally, we used clinical palpation to evaluate the masticatory muscles' functional state and employed MRI using the OCOR-T1WI-FSE-CLOSED, OSAG-PDW-FSE-CLOSED, and OSAG-PDW-FSE-OPEN sequences to analyze the texture of the lateral pterygoid muscle (LPM). Results: The proportion of any articular disc or condylar morphology class did not differ significantly between the TMJ clicking and HC groups. The articular disc position did not differ significantly between the TMJ clicking and HC groups. In the TMJ clicking group, the presence of masticatory muscle dysfunction differed significantly between the clicking and non-clicking sides. Moreover, the LPM accounted for the highest proportion among masticatory muscles with tenderness in all TMJ clicking subgroups (77.78%-100%). Therefore, in the TMJ clicking group, the LPM texture was less defined, more uniform in gray scale, and more similar to local texture (p < 0.0001). Conclusion: The occurrence of TMJ clicking in young adults is unrelated to the TMJ structure but related to the function of masticatory muscles, particularly the LPM.

Temporomandibular Joint Disk Displacement: Etiology, Diagnosis, Imaging, and Therapeutic Approaches

An estimated 8 to 15% of women, and 3 to 10% of men currently suffer from Temporomandibular disorders, and it has been reported that sounds are a common finding and have been observed in 28% to 50% of the adult population; sounds are almost always connected to "internal derangements" a condition in which the articular disk displaced from its position on the mandibular condyle. Due to the multifactorial etiology of temporomandibular joint dysfunction, any accurate diagnosis based on clinical examination alone often proves to be difficult, so a clinical examination should be utilized together with other imaging methods to determine the relationship between the disk and condyle before and after treatment. In general, management of temporomandibular joint-related conditions is necessary when pain or dysfunction is present, so many surgical or nonsurgical methods of treatment have been reported. The Occlusal splint is 1 of the most widespread treatment it induces a slight vertical condylar distraction and eliminates the occlusal factor, which can be responsible for Temporomandibular joint disturbances, removing the influence of the teeth on the joint position by the slight distraction of the joint which, in turn, enables damaged connective tissue to heal.

Botulinum toxin A in dentistry and orofacial surgery: an evidence-based review - part 1: therapeutic applications

Objective An evidence-based review on the safety and efficacy of botulinum toxin type-A (BoNTA) in orofacial conditions, focusing on the therapeutic applications and role of BoNTA as an adjuvant treatment.Data source and selection Data was collected using PubMed (Medline), Cochrane Library of Systematic Reviews and Cochrane Central Register of Controlled Trials electronic databases. Having satisfied the search parameters, 32 studies for therapeutic applications and 26 for BoNTA as an adjunctive treatment were included. The quality of relevant studies was assessed using the Best Evidence Topics (BETs) Critical Appraisal Tool.Data extraction The highest level of evidence (LOE) behind BoNTA safety and efficacy was for wound healing and scar management in the orofacial surgery context, where BoNTA was presented as an adjunctive modality. Level-I evidence was controversial for temporomandibular disorders and bruxism. However, it showed promising results for painful temporomandibular disorders of myogenic origin refractory to conservative therapies, and to decrease muscle contraction intensity in sleeping bruxism. There was only one level-II study for persistent recurrent aphthous stomatitis. Data showed limited level-III evidence for orofacial pain conditions (temporomandibular joint recurrent dislocation and pain, burning mouth syndrome or atypical odontalgia), oral cancer complications, or as an adjuvant to maxillofacial and orthognathic surgeries. Benefits of BoNTA in prosthodontics had weak level-IV evidence. No evidence was found among the periodontology field.Conclusion There is growing evidence to support the safety and efficacy of BoNTA in the investigated orofacial pathological conditions, with high levels of satisfaction from the patient and clinician perspective. However, there are some inconsistencies and limited high-quality evidence available. Well-designed controlled clinical trials are necessary to evaluate long-term safety, efficacy and cost-effectiveness before BoNTA is widely adopted with irrefutable evidence-based clinical guidelines.

Temporomandibular joint (TMJ) disorders prevalence and awareness of appropriate clinical practices, among Al-Madinah community in Saudi Arabia

Background:  Painful temporomandibular joint disorders (TMDs) are of musculoskeletal origin and are considered the most common cause of non-odontogenic pain in the orofacial region.  The purpose of this study was to investigate the prevalence and awareness of temporomandibular joint (TMJ) disorders in Almadinah Almunawwarah community. Methods: An observational cross-sectional study with convenience sampling was conducted. A translated Arabic version of Fonseca's questionnaire was employed. The questionnaire asked about the participant's personal information, if they thought they had TMDs, and who to visit for therapy if necessary. These were followed by 10 items from Fonseca's questionnaire, each with a three-point scale. Results: The questionnaire was completed by 598 people. Females made up 57.1% of the participants. TMDs were present in 61% of the population, with varying degrees of severity. Males (44.3%) were less affected than females (55.7%). The difference, however, was not statistically significant (P = 0.354). Out of the 61% TMDs Positive patients, 74.1% had mild TMDs symptoms, while 20.8% and 5.1%, respectively, had moderate and severe TMDs symptoms (P = 0.05). The severity of the symptoms was unaffected by demographic data (P > 0.05). Only 40% seek care, with 64.6% selecting for a dentist and 24.6% preferring for an orthopaedic specialist (P= 0.008). Conclusions: Participants from Al-Madinah had a greater prevalence of mild TMDs. The majority of the participants had no idea who to go to for treatment. The findings of this study highlight the importance of educational activities to enhance public awareness. Fonseca's Anamnestic Index could also be considered as a useful instrument for early identification and measuring the severity of TMDs in the general population.

Temporomandibular joint (TMJ) disorders prevalence and awareness of appropriate clinical practices, among Al-Madinah community in Saudi Arabia

Background:  Painful temporomandibular joint disorders (TMDs) are of musculoskeletal origin and are considered the most common cause of non-odontogenic pain in the orofacial region.  The purpose of this study was to investigate the prevalence and awareness of temporomandibular joint (TMJ) disorders in Almadinah Almunawwarah community. Methods: An observational cross-sectional study with convenience sampling was conducted. A modified version of Fonseca's questionnaire was employed. The questionnaire asked about the participant's personal information, if they thought they had TMDs, and who to visit for therapy if necessary. These were followed by 10 items from Fonseca's questionnaire, each with a three-point scale. Results: The questionnaire was completed by 598 people. Females made up 57.1% of the participants. TMDs were present in 61% of the population, with varying degrees of severity. Males (44.3%) were less affected than females (55.7%). The difference, however, was not statistically significant (P = 0.354). Out of the 61% TMDs Positive patients, 74.1% had mild TMDs symptoms, while 20.8% and 5.1%, respectively, had moderate and severe TMDs symptoms (P = 0.05). The severity of the symptoms was unaffected by demographic data (P > 0.05). Only 40% seek care, with 64.6% selecting for a dentist and 24.6% preferring for an orthopaedic specialist (P= 0.008). Conclusions: Participants from Al-Madinah had a greater prevalence of mild TMDs. The majority of the participants had no idea who to go to for treatment. The findings of this study highlight the importance of educational activities to enhance public awareness. Fonseca's Anamnestic Index could also be considered as a useful instrument for early identification and measuring the severity of TMDs in the general population.

Effect of two fascial incision options for access to the temporomandibular joint on facial nerve function: objective investigation

This study was performed to compare the effects on facial nerve (FN) function of the deep supra-temporalis muscle subfascial approach (DSFA) and traditional fascial approach (TFA) for access to the temporomandibular joint (TMJ), via qualitative and quantitative evaluations. Thirty patients requiring open TMJ surgery were randomly allocated to one of two groups: group A patients underwent the DSFA approach, while group B patients underwent the TFA approach. The TMJ was accessed via modified endaural incision with temporal extension. Clinical examinations, FN conduction tests, and electromyography (EMG) of the frontalis and orbicularis oculi muscles were used to assess FN function. A FN function deficit was noted in 50% of the whole sample population immediately after surgery, with no statistically significant difference between the groups (P = 0.082). Overall, 37.5% of the total study population experienced temporary loss of frontalis muscle activity, while zygomatic nerve injury was seen only in 25% of group A. Within 2-6 months, normal function returned in both groups. Nerve conduction studies showed no statistically significant difference between the groups in terms of nerve amplitude or latency after surgery. However, EMG of orbicularis oculi activity showed a significant difference between the groups after 6 months (P = 0.010). The results suggest that the traditional dissection approach is more protective of the FN, especially the zygomatic branch, than the deeper dissection technique.

A Novel Injection Technique to the Lateral Pterygoid Muscle for Temporomandibular Disorders: A Cadaveric Study

BACKGROUND

Lateral pterygoid muscle activity is associated with the pathological mechanisms of some temporomandibular disorders. The authors aimed to define and demonstrate a novel, practical, and safe technique for botulinum toxin type A injection to the lateral pterygoid muscle based on their findings. Their secondary aims were to standardize the injection pattern according to the variations of the lateral pterygoid muscle and its surrounding anatomical structures, and to establish its advantages over intraoral injection.

METHODS

Twenty cadaver heads were dissected. The lateral pterygoid muscle and its surrounding structures were investigated for anatomical variations. Based on these findings, a standardized extraoral injection protocol was defined and compared with the intraoral technique for accuracy and safety.

RESULTS

The average depth of the lateral pterygoid plate from the skin surface was 49.9 ± 2.2 mm, and the mean width of the lateral pterygoid plate was 10.5 ± 3.9 mm. The extraoral injection approach based on the location of the maxillary tuberosity, tragus, and lateral pterygoid plate was consistent in all dissections for the accuracy of the intramuscular injection. In the intraoral approach, standardization of the entry point of the needle through the oral mucosa is difficult, which makes adjustment of the depth of the injection challenging while increasing the risk of neurovascular injury.

CONCLUSIONS

The clinical significance of the lateral pterygoid muscle makes it worthwhile to implement minimally invasive treatments before considering more invasive options. The authors define a safe, accurate, and reliable approach with ease of administration in patients with temporomandibular disorders.

Gummy Smile Management Using Diode Laser Gingivectomy Versus Botulinum Toxin Injection - A Prospective Study

Introduction:

Gummy smile (GS) is a nonesthetic condition that affects the confidence of many young people. The present study aimed to compare the results of two approaches used in the management of GS in a group of Egyptian females.

Materials and Methods:

This comparative cohort study included 24 female patients aged 25–35 years, divided into two groups. Group A included patients treated with diode dental laser gingivectomy, while Group B included patients who were treated with Botox injection. The clinical assessment of the pre-and post-operative measurements of exposed gums in millimetres on an active full smile was analyzed and compared for both groups. The paired t-test was used to compare pre and post measurements in each group, and the mean difference between the groups was compared using the independent t-test.

Results:

Group A showed instant improvement, while Group B results appeared 1 week later. The variation between preoperative and postoperative GS measurements in both groups was statistically significant. The preoperative and postoperative mean ± standard deviation was (5.17 ± 0.9 and 1.89 ± 0.5) in Group A and (4.27 ± 1.0 and 1.79 ± 1.0) in Group B. Comparison between the two groups revealed a highly significant greater mean difference of 3.27 ± 0.5 mm in Group A than Group B (P < 0.001). The findings were satisfactory in all cases of both approaches, and there were no complications.

Discussion:

Using a diode laser to treat gummy smiles for oro-dental genetics case with gingival hypertrophy saves time and effort compared to conventional surgical techniques. Diode dental laser is a safe fast and effective method of treatment giving more superior results than Botox injection which showed a less invasive alternative temporary GS therapy that is easily guaranteed and more patient-favored.

Intramuscular Injections and Dry Needling within Masticatory Muscles in Management of Myofascial Pain. Systematic Review of Clinical Trials

Background: Myofascial pain is an important cause of disability among the whole population, and it is a common symptom of temporomandibular joint disorders (TMDs). Its management techniques vary widely; however, in recent years, there has been a growing interest especially in needling therapies within masticatory muscles, due to their simplicity and effectiveness in pain reduction. Methods: The construction of the following study is based on PICOS and PRISMA protocols. A systematic literature search was conducted based on the PubMed and BASE search engines. Searching the abovementioned databases yielded a total of 367 articles. The screening procedure and analysis of full texts resulted in the inclusion of 28 articles for detailed analysis. Results: According to analyzed data, clinicians manage myofascial pain either with wet or dry needling therapies. The most thoroughly studied approach that prevails significantly within the clinical trials is injecting the botulinum toxin into the masseter and temporalis. Other common methods are the application of local anesthetics or dry needling; however, we notice the introduction of entirely new substances, such as platelet-rich plasma or collagen. In the analyzed articles, the target muscles for the needling therapies are most commonly localized by manual palpation although there are a variety of navigational support systems described: EMG, MRI or EIP electrotherapy equipment, which often aid the access to located deeper lateral and medial pterygoid muscle. Conclusions: Needling therapies within masticatory muscles provide satisfactory effects while being simple, safe and accessible procedures although there still is a need for high quality clinical trials investigating especially injections of non-Botox substances and needling within lateral and medial pterygoid muscles.

In-house tooth-supported guide for the injection of botulinum toxin into the lateral pterygoid muscle using Blue Sky Plan software: A technical note

Hyperactivity of the lateral pterygoid muscle (LPM) is one of the theories postulated to explain anterior disc displacement, which can result in difficulty in jaw opening, jaw protrusion, or jaw-deviation dystonias and interferes with mastication, speech, and swallowing. Injection of botulinum toxin of the LPM is considered a conservative therapeutic modality for this condition. The LPM is a deep facial structure and several techniques have been described that use magnetic resonance imaging, arthroscopic, or electromyographic guidance to perform intramuscular botulinum toxin injection safely this to prevent incorrect injection or complications, such arterial bleeding. This study provided a described step-by-step description of the computer-aided design and manufacturing procedure for the fabrication of an in-house guide to simplify the method of botulinum toxin injection in the LPM and ensure accuracy and safety in medical office.

Velopharyngeal dysfunction following botulinum toxin type A injection to the lateral pterygoid muscles for recurrent jaw dislocation

Complications related to lateral pterygoid muscle (LPM) botulinum toxin A (BtA) injection for recurrent temporomandibular joint dislocation are uncommon. No cases of velopharyngeal dysfunction (VPD) following LPM BtA injection have been reported to date. This report details the perioperative and follow-up findings for a patient developing VPD following LPM BtA injection.