Search Results (81)

Background and objectives: Trismus is a frequent and debilitating complication in people with head and neck cancer (HNC) which leads to significant functional limitations and reduced quality of life. Rehabilitation interventions are commonly recommended to manage or prevent trismus. However, in many randomized controlled trials (RCTs), the theoretical justification for these interventions is poorly articulated, and the underlying biological or physiological mechanisms are not described in detail, limiting our understanding of why certain treatments may (or may not) work. This review aimed to identify and analyze how RCTs report the rationale for rehabilitation interventions and the explanations used to manage this population. Materials and Methods: A scoping review was conducted in accordance with the PRISMA-ScR guidelines. Five databases (PubMed, PEDro, Web of Science, Scopus, and EMBASE) were searched up to May 2025 for RCTs evaluating rehabilitation interventions for the management or prevention of treatment-induced trismus in patients with HNC. Data were extracted and synthesized narratively, focusing on the type of intervention, the rationale for its use, and the proposed mechanisms of action. Results: Of 2215 records identified, 24 RCTs met the inclusion criteria. Thirteen studies focused on preventive interventions—primarily exercise therapy—while the remainder addressed established trismus using exercise, manual therapy, electrotherapy, or combined treatment modalities. The rationales provided for intervention selection were heterogeneous and often lacked depth, with most studies justifying interventions based on their potential to improve mouth opening or reduce fibrosis but rarely grounding these claims in detailed pathophysiological models. Only half of the studies provided any mechanistic explanation for the intervention’s effects, and these were typically generic or speculative. Conclusions: RCTs investigating rehabilitation interventions for treatment-induced trismus in patients with HNC frequently lack comprehensive rationales and mechanistic explanations for their interventions. This gap limits the ability to refine and optimize treatment approaches, as the underlying processes driving clinical improvements remain poorly understood. Future research should be guided by theoretical models and include objective outcomes to better elucidate the mechanisms of action of interventions to inform clinical practice. Full article

Background/Objectives: Mandibular coronoid process hypertrophy (MCPH) is a rare condition characterized by an abnormal enlargement of the mandibular coronoid process, resulting in restricted mouth opening and reduced lateral mandibular movements due to interference with the zygomatic bone. The objective of this paper is to evaluate the functional outcomes of intraoral coronoidectomy followed by physiotherapy in five consecutive patients with MCPH. Methods: Five male patients (mean age 38 ± 18.7 years) with radiologically confirmed bilateral MCPH underwent intraoral coronoidectomy between May 2020 and December 2022. Maximal inter-incisal opening (MIO) was measured pre-operatively, on postoperative day 1, and at 6-month follow-up. A standardized 5-10-60 mouth-opening exercise protocol using a Heister mouth gag was administered from postoperative day 1. Results: The hyperplastic mandibular coronoid processes were removed intraorally without any long-lasting complications. All patients demonstrated a postoperative increase in mouth opening. Notably, patients with more severe mouth-opening limitations showed greater improvement compared with those with milder initial restrictions. Conclusions: Intraoral coronoidectomy, combined with early and intensive physiotherapy, represents a safe and effective treatment for MCPH. Early diagnosis and timely surgical intervention are crucial to prevent ineffective non-surgical management. Additionally, a modest initial postoperative increase in mouth opening should not be considered the final outcome, as these patients often achieve substantial long-term functional improvement. Full article

Ambrosia beetles have evolved specialized structures termed “mycangia”, which house and transport symbiotic microbes. Microbial partners include at least one obligate mutualistic filamentous fungus used as food for larvae and adults, and potentially secondary filamentous fungi, yeasts, and bacteria. Beetles in the genus Xyleborus possess paired pre-oral mycangial structures located within the head on either side of the mouth parts. Mycangia develop in pupae, with newly emerged adults acquiring partners from the environment. However, information concerning the cellular structure and function of Xyleborus mycangia remains limited. We show that in X. affinis, mycangia are lined with a layer of striated dense material, enclosing layers of insect epithelial cells, with diverse spine-like structures. Larger (5–10 μm) projections were concentrated within and near the entrance of mycangia, with smaller filaments (4–8 μm) within the mycangia itself. Rows of “eyelash” structures lined the inside of mycangia, with fungal cells free-floating or in close association with these projections. Serial sections revealed mandibular articulations, and mandibular, pharyngeal, and labial muscles, along with the mycangial entry/exit channel. Sheets of comb-like spines at the mycangial entrance and opposite the mycangia attached to the roof of the labrum or epipharynx may serve as an interlocking mechanism for opening/closing the mycangia and guiding fungal cells into entry/exit channels. Additionally, mandibular fibra (muscle tissue) potentially enervating and affecting the mechanism of mycangial functioning were noted. These data add crucial mechanistic detail to the model of pre-oral mycangia in Xyleborus beetles, their cellular structures, and how they house and dispense microbial symbionts. Full article

Background and Clinical Significance: Local anesthetic injections, routine in dental practice, ensure pain control during procedures like root canal treatments. Though generally safe, they can occasionally cause hematomas, localized blood accumulations in tissue planes. Rapidly expanding hematomas in the head and neck are exceptionally rare but dangerous due to anatomical complexity, potentially threatening the airway. This case report emphasizes the critical need for the prompt recognition and management of such complications to prevent life-threatening outcomes, highlighting vigilance in routine dental procedures. Case Presentation: A 63-year-old male presented with rapidly enlarging right buccal swelling four hours post-local anesthetic injection for a root canal on a right maxillary molar. Examination showed warm, erythematous edema and buccal ecchymosis; a CT scan confirmed a 3.8 cm × 8.4 cm × 5.5 cm buccal space hematoma. His medical history revealed controlled type 2 diabetes and hyperlipidemia, and his coagulation was normal. Conservative management failed as the hematoma progressed, limiting mouth and eye opening. Urgent surgical decompression under general anesthesia evacuated clots and ligated facial and angular arteries. ICU monitoring ensured airway stability, with discharge on day three with antibiotics and follow-up. Conclusions: This case highlights the rare potential for dental anesthetic injections to cause rapidly progressive hematomas, requiring urgent surgical intervention and multidisciplinary care to prevent airway compromise. Early recognition, imaging, and decisive management are vital in achieving favorable outcomes in such serious complications. Full article

Background/Objectives: Temporomandibular disorder (TMDs) patients often present limited mouth opening (LMO). A key diagnostic cutoff is a mouth opening threshold >40 mm. However, this universal cutoff may not accurately reflect gender anatomical variations. This study investigates gender-specific differences in maximum mouth opening (MMO) to propose revised diagnostic criteria for LMO. Methods: A five-year prospective study was conducted from 1 August 2019 to 1 May 2024 in a Portuguese TMDs department. The patients’ gender, MMO, and LMO complaints with clinical validation were recorded. Statistical analyses, including Generalized Additive Models (GAMs) and Generalized Linear Models (GLMs), assessed the relationship between MMO and LMO, with gender-stratified comparisons. Results: In this study 1045 patients were included. The median (accompanied by the interquartile range [25th percentile–75th percentile]) MMO was lower in females (40 mm [34–45]) than in males (44 mm [40–48]). Patients presenting LMO complaints exhibited significantly reduced MMO values compared to those without LMO complaints (p < 0.001). Gender-specific thresholds emerged: for females, LMO was observed when MMO was ≤35 mm, while in males, LMO symptoms appeared when MMO was ≤38 mm. A “gray zone” of diagnostic uncertainty was identified between 36 and 37 mm for females and 38 and 42 mm for males. Conclusions: In this study we observed the gold standard cutoff for diagnosing MMO in female should be <35mm and for male <38mm. These findings suggest that a single LMO threshold does not account for gender-related anatomical differences, potentially leading to underdiagnosis in females and misclassification in males. Revising diagnostic criteria to incorporate gender-specific thresholds could enhance accuracy, improve early diagnosis, and promote personalized treatment strategies for TMDs patients. Further research incorporating additional variables such as age, dental occlusion, craniofacial structure, and body mass index is recommended to refine these diagnostic guidelines. Full article

Background/Objectives: Temporomandibular disorders are a heterogeneous group of degenerative musculoskeletal conditions that present a series of symptoms such as pain, dysfunction of the masticatory muscles and/or temporomandibular joints, structural abnormalities, and limitation or alteration of mandibular movements. The objective of this study was to evaluate the efficacy of photobiomodulation therapy with low-power laser in patients refractory to treatment with botulinum toxin type A. Methods: A multicenter prospective experimental pilot study was proposed, in which 10 patients between 33 and 68 (50 ± 11.2) years old participated, assigned to a laser group (940 nm diode laser) who had previously been treated with a minimum of three doses of botulinum toxin type A without obtaining positive results. The patients underwent four photobiomodulation sessions over 4 weeks (registered at ClinicalTrials NCT06915064). Painful symptoms were evaluated using a visual analog scale at different locations, the pressure pain threshold using algometry, and the maximum vertical mandibular movement determined using digital calipers. The results were recorded four weeks after the end of treatment. Adverse effects were also evaluated. Results: Pain in the masticatory muscles was reduced in 70% of patients with statistically significant values (p = 0.002); a total of 60% of patients showed a considerable reduction in joint noise with outstanding statistical significance (p = 0.015). The majority of participants reported a reduction in the intensity of headaches after treatment. However, it only produced a slight improvement in maximum mouth opening and lateral excursions. Algometric values in the masticatory muscles showed improvement only in the left-sided irradiated muscles. Conclusions: Photobiomodulation therapy is a non-invasive treatment option for temporomandibular disorders that generates positive effects in cases refractory to treatment with botulinum toxin type A. Full article

(1) Background: A sedentary lifestyle may aggravate temporomandibular disorder (TMD) symptoms, increasing pain sensitivity and functional limitations. Physical exercise is recommended for pain management and improving quality of life. Comparing CrossFit^® athletes to sedentary individuals allows for examining whether regular high-intensity exercise impacts pain sensitivity and functional limitations associated with TMD. This cross-sectional study assessed the signs and symptoms of TMD in CrossFit^® athletes compared to sedentary individuals. (2) Methods: Participants (n = 121) were divided into four groups: sedentary with TMD (n = 39), sedentary without TMD (n = 37), CrossFit^® athletes with TMD (n = 23), and CrossFit^® athletes without TMD (n = 22). TMD signs and symptoms were evaluated using the Research Diagnostic Criteria for TMD (RDC/TMD) axis I, including mandibular movement patterns, range of motion, joint sounds, muscle pain, and jaw dysfunctions. Statistical analyses included chi-square and Dunn’s post hoc tests, ANOVA, and Kruskal–Wallis tests. Correlation and regression analyses were performed to examine associations between CrossFit^® practice and TMD (p ≤ 0.05). (3) Results: Myofascial pain was the most common diagnosis. All athlete groups exhibited greater mandibular movement amplitudes (unassisted opening without pain, p < 0.001, and protrusion, p = 0.039) and less pain (p < 0.001) than sedentary individuals. Pain reports and palpation-induced pain in muscles and joints were significantly associated with a sedentary lifestyle and TMD (p < 0.001). Joint and muscle pain were more prevalent (frequent) among sedentary participants, regardless of TMD diagnosis. Linear regression analysis showed that sedentary individuals without TMD had significantly reduced unassisted mouth opening amplitudes compared to athletes without TMD (p < 0.05). (4) Conclusions: Pain in the masseter, temporalis, posterior digastric, and medial pterygoid muscles was the most common symptom in sedentary individuals with TMD. They experience higher frequency and intensity of pain, as well as greater limitations in mouth movement. Athletes showed higher frequency of joint noises. Full article

Background: Digital planning and the use of a static surgical guide for implant placement provide predictability and safety for patients and practitioners. The aim of this study was to investigate differences in the accuracy and fit of long and short guides. Methods: In patients with at least one missing tooth, long (supported by the entire dental arch) and short templates (supported by two teeth, mesial and distal) were compared via intraoral scans and the superimposition of the STL files of the initial planning and the actual position in the patient’s mouth along the X-, Y- and Z-axes. Furthermore, this study evaluated the conditions (e.g., mouth opening, the implant position) under which fully guided implantation can be realized. Results: The largest deviation was observed in the Z-axis, although this deviation was not as high for the short templates (0.2275 mm) as it was for the long templates (0.4007 mm). With respect to the 3D deviation (dXYZ), the average deviation from the mean value was 0.2953 mm for the short guides and 0.4360 mm for the long guides (p = 0.002). The effect size (Cohen’s d) was 0.709, which was between the medium (0.50) and large effect sizes (0.80). The shorter templates showed a smaller deviation from the actual plan by 80%. With a mouth opening ≥50 mm, fully guided surgery can be performed in the molar region. In the premolar region, the lower limit was 32 mm. Conclusions: The 3D accuracy was significantly higher for the shorter template, which could therefore be favored. Full article

Background: The objective of this study is to investigate the cone beam computed tomography (CBCT) features of the coronoid process in patients without limitations in mouth opening and to develop a functional classification of the coronoid process, considering its relationship with the zygomatic bone. Methods: This cross-sectional retrospective study analyzed the CBCT features of 408 coronoid processes. Volume rendered and axial images were evaluated to assess the shape, surface configuration, length of the coronoid process, the coronoid/condyle ratio, the distance of the coronoid process from the posteromedial surface of the zygoma, and its vertical level. The coronoid process was considered hyperplastic when the coronoid/condyle ratio was >1. Results: The maximum coronoid processes had a triangular shape (221). The mean length of the coronoid process was 13.85 mm. The mean coronoid/condyle ratio was 0.84. A total of 85 coronoid processes were hyperplastic. The mean distance from the coronoid process to the posteromedial surface of the zygoma was 15.99 mm, ranging from 5.8–27.9 mm. The mean vertical level of the coronoid process in the study sample was 9.6 mm. A novel functional radiographic classification was developed. The coronoid processes were classified as Type I, II, III (a,b,c), and IV (a,b,c). Type IIIa was the most common (45.83%), followed by Type II (29.68%), Type I (16.17%), Type IIIc (4.41%), Type IIIb (3.18%), Type IVa (0.49%), and Type IV b (0.24%). Conclusions: The vertical extension of the coronoid process beyond the lower border of the zygomatic bone/arch and its distance from the posterior surface of the body of the zygoma could play a significant role in impacting the mandibular movements. Full article

Objectives: This study aims to describe and analyze the indications and clinical results of total TMJ replacement in participants with degenerative and/or inflammatory joint diseases, defining patient and intervention conditions. Methods: A systematic review was conducted according to the Cochrane Handbook for Systematic Reviews of Intervention and reported according to the PRISMA Items update. The search strategy was from 1997 to July 2024 in Pubmed, Embase, Scopus, and Web of Science. A search for gray literature was conducted in the databases Google Scholar and Open Access Theses and Dissertations (OATD), and there were no limitations on the language or study design. We incorporated studies involving human patients over 15 years of age with degenerative and/or inflammatory joint conditions who underwent joint prosthesis replacement, either concurrently or separately from orthognathic surgery, as an initial intervention or after prosthesis installation. Participants with a postoperative follow-up of 12 months or longer were included. A risk of bias analysis was performed for non-randomized studies using the ROBINS-I tool, and GRADE profiler (GRADEpro) software was used to assess the quality of evidence and synthesize the data. Results: All the selected studies performed postoperative follow-up with quantitative and qualitative parameters; 10 performed a follow-up of 2 to 5 years. The indication for joint prosthesis replacement due to system failure was only 4.07%. Concerning diagnoses, 579 presented degenerative and/or inflammatory joint diseases, with osteoarthritis being the most frequent, followed by osteoarthrosis, juvenile idiopathic arthritis, and rheumatoid arthritis. The maximum mouth opening of the participants with TMJ disease presented an average of 24.32 ± 5.8 mm with a range of 18 to 36.4 mm. Of the 579 participants, the studies mention that they presented a soft to liquid diet and pain associated with decreased mandibular functionality. Conclusions: A total of 76.18% of the participants presented a range of moderate to severe pain associated with a decrease in functionality and, after joint replacement, all participants mentioned a decrease in pain or absence of pain, a change in diet by incorporating solid foods, and an increase in opening with an average of 40.74 ± 3.1 mm. Total joint replacement shows favorable long-term results. It is not possible to identify the best time to perform joint replacement surgery, considering the time since diagnosis of the disease, the time since the start of non-surgical treatment, or the number of previous surgeries. Full article

Drowsy driving contributes to over 6000 fatal incidents annually in the US, underscoring the need for effective, non-intrusive drowsiness detection. This study seeks to address detection challenges, particularly in non-standard head positions. Our innovative approach leverages computer vision by combining facial feature detection using Dlib, head pose estimation with the HOPEnet model, and analyses of the percentage of eyelid closure over time (PERCLOS) and the percentage of mouth opening over time (POM). These are integrated with traditional machine learning models, such as Support Vector Machines, Random Forests, and XGBoost. These models were chosen for their ability to process detailed information from facial landmarks, head poses, PERCLOS, and POM. They achieved a high overall accuracy of 86.848% in detecting drowsiness, with a small overall model size of 5.05 MB and increased computational efficiency. The models were trained on the National Tsing Hua University Driver Drowsiness Detection Dataset, making them highly suitable for devices with a limited computational capacity. Compared to the baseline model from the literature, which achieved an accuracy of 84.82% and a larger overall model size of 37.82 MB, the method proposed in this research shows a notable improvement in the efficiency of the model with relatively similar accuracy. These findings provide a framework for future studies, potentially improving sleepiness detection systems and ultimately saving lives by enhancing road safety. Full article

Periapical radiography is a regular radiographic procedure performed by dentists. However, at times, it may not be possible to position the image receptor into a patient’s mouth in an optimized or practical way. For these cases, some dentists advocated the use of extraoral periapical radiography (EOPA). This literature review aimed to review the dental literature on the use of EOPA. In October 2023, PubMed, Web of Science, and Scopus were searched to identify papers that reported on the use of EOPA, supplemented by manual reference tracing and Google Scholar searches. After screening, 18 papers published between 2003 and 2022 were identified, including 14 original articles and 4 reviews. From very limited and conflicting evidence, it was found that root length/working length measurements between EOPA and IOPA did not significantly differ or EOPA showed inferiority. No data were available to compare EOPA with other extraoral modalities such as panoramic radiography. The technique used in EOPA to visualize posterior teeth in the maxilla and mandible varied across studies, such as the vertical angulation of the primary beam, whether mouth should be opened or closed, and whether a holder should be used or not. At the current time, EOPA probably should not be advocated for regular use. Full article

Coastal lagoons are important wetland sites for migratory species and the local flora and fauna population. The Stagnone Lagoon is a coastal lagoon located on the west edge of Sicily between the towns of Marsala and Trapani. The area is characterized by salt-harvesting plants and several archaeological sites and is affected by microtidal excursion. Two mouths allow exchange with the open sea: one smaller and shallower in the north and one larger and deeper in the south. This study aims to understand the lagoon’s hydrodynamics, in terms of circulation and involved forces. The circulation process appears to be dominated mainly by tide excursions and wind forces. Wind velocity, water levels, and water velocity were recorded during different field campaigns in order to obtain a benchmark value. The hydrodynamic circulation has been studied with a 2DH (two-dimensional in the horizontal plane) unstructured mesh model, calibrated with data collected during the 2006 field campaign and validated with the data of the 2007 campaign. Rapid changes in averaged velocity have been found both in Vx and Vy components, showing the strong dependence on seiches. This study tries to identify the main factor that domains the evolution of the water circulation. Sensitivity analyses were conducted to estimate the correct energy transfer between the forcing factors and dissipating ones. A Gauckler–Strickler roughness coefficient between 20 and 25 m^1/3/s is found to be the most representative in the lagoon. To enhance the knowledge of this peculiar lagoon, the MIKE 21 model has been used, reproducing all the external factors involved in the circulation process. Nash–Sutcliffe coefficient of efficiency (NSE) values up to 0.92 and 0.79 are reached with a Gauckler–Strickler coefficient equal to 20 m^1/3/s related to water depth and the Vy velocity component. The Vx velocity component NSE has never been satisfying, showing the limits of the 2D approach in reproducing the currents induced by local morphological peculiarities. Comparing the NSE value of water depth, there is a loss of up to 70% in model predictivity capability between the southern and the northern lagoon areas. This study aims to support the local decision-makers to improve the management of the lagoon itself. Full article

The C-MAC video stylet (Karl Storz KG, Tuttlingen, Germany) is proposed as a successor to the familiar retromolar intubation endoscope. With its flexible tip, it may be especially useful for patients with a limited mouth opening. An awake or sedated airway management technique is often preferred when a difficult airway is anticipated. Due to the challenges in preparation, sedation, topical airway anesthesia and the execution of such an airway management technique itself, these techniques are often clinically underused. The C-MAC video stylet seems to be well suited for an awake or sedated airway approach, as its handling is easier and faster than a flexible fiberscope. It does not exert pressure on the tongue as direct laryngoscopy or video laryngoscopy do. We report two cases of a difficult airway in which intubation was performed by using the C-MAC video stylet in sedated, spontaneously breathing patients. After a low dose of 3 mg midazolam IV, remimazolam was administered continuously (0.46–0.92 mg/kg/h). This was supplemented with a low dose of remifentanil (0.04–0.05 µg/kg/min). The Trachospray device (MedSpray Anesthesia BV, Enschede, The Netherlands) was used for topicalization of the upper airway by means of 4 mL of lidocaine 5%. In addition, a further 5 mL of lidocaine 5% was sprayed via an epidural catheter advanced through the oxygenation port of the C-MAC video stylet for further topicalization of the vocal cords and proximal part of the trachea. The well-coordinated steps described in these two cases may represent a blueprint and a good starting point for future studies with a larger number of patients. Full article

Background/Objectives: Temporomandibular disorders (TMD) encompass a range of musculoskeletal and neuromuscular conditions affecting the temporomandibular joint (TMJ) and associated structures. This cross-sectional study, conducted in a Portuguese TMD department, aimed to assess the relationship between malocclusion and TMD severity. Methods: Data on demographic variables, TMD clinical symptoms, and malocclusion classes were collected using the EUROTMJ database. The Chi-square test (χ²) identified associations, with their intensity measured by Cramér’s V (φc). Results: The study included 1170 patients (932 females and 238 males), with a mean age of 41.73 ± 16.80 years. Most patients exhibited Angle Class I malocclusion (85.5%), followed by Angle Class II (13.5%) and Angle Class III (1.1%). Class II malocclusion was associated with increased TMD severity (p < 0.001), higher myalgia levels (p = 0.002), more frequent disc displacement without reduction (p = 0.002) and lower maximum mouth opening values (Class II: 38.13 ± 7.78 mm, Class I: 39.93 ± 8.67 mm). Significant associations were also found between malocclusion type and arthralgia (p = 0.021), mouth-opening limitation (p = 0.016), and TMJ crepitus (p = 0.017). In cases of malocclusion, the presence of oral signs of bruxism explained the degree of myalgia, disc displacement, and severity (p = 0.003; p = 0.048; p = 0.045). Conclusions: This study highlights that (1) the most common type of dental malocclusion in TMD patients was Class I; (2) Class II malocclusion was associated with increased TMD severity and oral signs of bruxism; and (3) Class III was rarely observed in TMD consultation. The findings suggest that bruxism behavior in cases of malocclusion may be significant in TMD. Full article