Protrusive Movements Research Articles

Retrospective epidemiological study over 8‐year period on zygomatic complex fractures: A single centre experience

AbstractObjectivesThe purpose of this study was to do a retrospective analysis of patients with zygomatic fractures who were treated at the Department of Maxillofacial Surgery, Regional University Hospital of Perugia, Italy, between 2016 and 2023.Materials and MethodsPatients were evaluated based on various parameters including age, sex, aetiology, symptoms, comorbidity, clinical findings, zygomatic fracture type, other facial fractures, treatment, waiting time before the operation, complications and sequelae. In the period described, we had 123 cases of zygomatic fractures requiring surgical intervention.ResultsAmong the patients, 101 were male (82.1%) and 22 were female (17.9%). The average age of the patients was 48.65 years (ranging from 7 to 94 years).The leading cause of these fractures was sports‐related injury (n = 32; 26.01%), and isolated zygomatic bone fractures were the most frequent (72.43%). The most common clinical signs and symptoms were pain, depression of the facial profile, difficulty in chewing, limitation of the buccal opening, difficulty in protrusion movements and mandibular lateralization. Ninety‐six per cent of patients underwent surgery under general anaesthesia, with open reduction and internal fixation.ConclusionsThe successful and effective management of zygomatic fractures requires a solid understanding of its anatomy, pathophysiology and related biomechanical structures and forces. The continuous research in epidemiology, aetiology, materials and techniques will further refine our treatments which are nowadays more and more customized according to the type of trauma.

4D Analysis of the Mandibular Protrusion Movement in Patients with Severe Malocclusion Before and After Orthognathic Surgery

4D Analysis of the Mandibular Protrusion Movement in Patients with Severe Malocclusion Before and After Orthognathic Surgery

Clinical outcomes of patients with unilateral internal derangement of the temporomandibular joint following arthrocentesis and stabilization splint therapy

BackgroundThe management of internal derangement (ID) of the TMJ is challenging because of multiple etiologic factors and varying degrees of severity. The aim of this study was to evaluate the clinical outcomes of patients with unilateral ID treated with arthrocentesis and stabilization splint therapy during a 6-month period.MethodsA total of 105 patients (87 females, 18 males) with unilateral ID were included in this study. Patients were divided into unilateral anterior disc displacement with reduction (ADDwR) and unilateral anterior disc displacement without reduction (ADDwoR). Patients with ADDwoR were subdivided according to the erosive bone changes. Objective parameters on mandibular movement and subjective parameters on pain were obtained and assessed.Their clinical outcomes before and after arthrocentesis and stabilization splint therapy were compared with the chi-square, Fisher’s exact test, paired t-test, or Wilcoxon singed-rank test.ResultsAll objective parameters of unilateral ID patients significantly increased at the 6-month follow-up. The differences in mean visual analog scale (VAS) pain scores were statistically significant in all subjective variables (p < 0.01). In joints with ADDwoR, preoperative maximal mouth opening, and maximal protrusive movement in both groups, with erosive and non-erosive changes were significantly increased after 6 months (p < 0.01). However, right and left maximal lateral movement increased after treatment in both groups but without significant differences. All VAS pain scores on jaw movement and palpation of associated muscles showed a significant decrease regardless of erosive changes.ConclusionsThe combination of arthrocentesis and subsequent stabilization splint therapy was shown to be highly effective in pain reduction and improvement of mandibular movements in both unilateral ADDwR and ADDwoR, as well as in cases with both erosive and non-erosive bony changes associated with unilateral ADDwoR.

Computerized Axiographic Findings in a Cohort of Migraine Patients: A Cross-Sectional Study.

The objective of this work was to investigate the association between the function of the stomatognathic system and migraine presence through an instrumental functional analysis in a group of diagnosed migraine patients and a control group. This study included 50 individuals in each group. A jaw-tracking analysis was performed using Cadiax 4. Tracings of the following movements were recorded: open/close, protrusion/retrusion, mediotrusion, speech, bruxing, and mastication. The tracings were evaluated for their quantity, quality, transversal characteristics, speed, curvature pattern, and condylar stability. Statistically significant differences between the groups were established for several aspects of the evaluation. Migraineurs presented with (a) higher values of mandibular lateral translation in protrusion/retrusion (p = 0.001), open/close (p = 0.031), and mastication (p = 0.016); (b) transient velocity losses in open/close (p = 0.001) and protrusive movements (p = 0.018); (c) a compromised condylar stability for protrusion/retrusion (p = 0.001) and mediotrusion (p = 0.003); (d) a compromised quality for protrusion/retrusion (p < 0.001) and mediotrusion (p = 0.003); and (e) a more frequent "figure-eight" curvature in open/close (p = 0.012). The importance of the stomatognathic function in migraine pathogenesis and treatment should be considered by using a patient-centered and interdisciplinary approach.

Effectiveness and safety of hominis placental pharmacopuncture for chronic temporomandibular disorder: A multi-center randomized controlled trial

BackgroundHominis placental (HPP) extract has been approved by the Ministry of Food and Drug Safety in Korea for treating chronic liver diseases and postmenopausal syndrome. However, its efficacy and safety for treating chronic temporomandibular disorder (TMD) remains unclear. We aimed to assess the effectiveness and safety of HPP for treating chronic TMD compared with physical therapy (PT). MethodsThis study is a 2-arm parallel, multi-center, randomized controlled trial. We enrolled 82 chronic TMD patients from 2 Korean medicine hospitals between December 2019 and January 2021. We included patients with chronic TMD and randomly assigned them to undergo HPP or PT. The primary outcome was the difference in the scores for temporomandibular joint (TMJ) pain at baseline and week 6. The secondary outcomes were the scores for TMJ pain and bothersomeness, TMJ range of motion, the Korean version of Beck's depression index-Ⅱ, jaw functional limitation scale (JFLS) score, patient global impression of change (PGIC) scores, EuroQoL 5-dimension 5-level score, and short form-12 health survey (SF-12) scores. ResultsCompared with PT, HPP showed significantly superior effects on TMJ pain and bothersomeness, protrusive movement pain, JFLS (verbal, emotional, and global), SF-12, and PGIC scores at week 6 (P < 0.05). Compared with the PT group, the HPP group showed a significantly higher recovery rate (≥50 % reduction in the scores for TMJ pain at the 24-week follow-up). ConclusionHPP was more effective than PT managing pain and improving function and quality of life. Our findings demonstrate the effectiveness and safety of HPP for TMD treatment. Trial registrationThis study has been registered at clinicalTrials.gov (NCT04087005), Clinical Research Information Service (CRIS) (KCT0004437), and Ministry of Food and Drug Safety (No. 31886).

Evaluation of mandibular motion in adolescents with skeletal class II division 1 malocclusion during mandibular advancement using clear functional aligners: a prospective study

BackgroundThis study aimed to evaluate the characteristics of mandibular protrusive condylar trajectory in adolescents with skeletal Class II Division 1 malocclusion and the changes of condylar trajectory during mandibular advancement (MA) treatment using clear functional aligners.MethodsThis prospective study consisted of a cross-sectional study and a longitudinal study. In cross-sectional study, sixty-one adolescents were divided into two groups: Class I (n = 30) and Class II Division 1 (n = 31). The condylar trajectory was measured and compared using the Mann–Whitney U test. The longitudinal study was the MA treatment group using clear functional aligner and consisted of 16 participants from Class II Division 1group. The condylar trajectory was collected at three-time points: pre-treatment (T1), during MA treatment at approximately 3 months (T2, 105.6 days average), and at the end of MA treatment (T3, 237.6 days average). The changes at T1, T2, and T3, as well as the symmetry between the left and right condyles across all groups, were examined using the Wilcoxon paired test.ResultsA greater increase in the anteroposterior displacement and space displacement during protrusive movements was observed in the Class II Division 1 group compared with that in the Class I group, with a large difference being observed in the left and right condylar movements. The condylar anteroposterior displacement and space displacement decreased significantly at T2 and increased significantly at T3; however, no significant difference was observed between T1 and T3. A significant difference was observed between the condylar movement on the left and right sides at T1; however, no significant difference was observed at T2 and T3.ConclusionsAdolescents with Class II Division 1 malocclusion had higher protrusive capacity than those with Class I. Moreover, their left and right condylar motion was more asymmetric. The range of condyle motion decreased first and then increased during MA therapy, and the left and right condyle movement became more symmetrical, which may be the adaptive response of neuromuscular function to the changes in jaw position.

Investigation of the accuracy of dynamic condylar position: A model study

ObjectivesTo evaluate dynamic condylar positions by integrating mandibular movement recording data and cone-beam computed tomography (CBCT) and to investigate its accuracy via dynamic model experiments. MethodsA polyvinyl chloride skull model was utilized. A robot arm was used to operate the mandible to perform mouth opening, closing, protrusion, and lateral movements. A recording device, worn on the skull, was used to record the dynamic process and an optical position tracking (OPT) system was used to simultaneously trace the movements. A self-developed software module was used to evaluate the dynamic condylar position by integrating the dynamic tracing data and a virtual skull model derived from CBCT images. Errors were defined as differences between the dynamic coordinates of six landmarks around the condylar area derived from the software module (test) and OPT system (gold standard). ResultsThe condylar position errors were 0.76 ± 0.31, 0.55 ± 0.15, and 0.68 ± 0.23 mm for mouth opening, bilateral, and protrusion movements, respectively. Furthermore, the errors for small, moderate, and large mouth opening movements were 0.62 ± 0.19, 0.69 ± 0.29, and 0.94 ± 0.31 mm, respectively. The errors for all movements, except for large mouth opening, were significantly less than 1 mm (P < 0.05). The error was not different from 1 mm in the large mouth opening movement (P > 0.05). ConclusionsOur developed method of achieving dynamic condylar position by integrating mandibular movement recording data and CBCT images is clinically reliable. Clinical significanceThis study proved the reliability of evaluating dynamic condylar position using a commercial dynamic recording instrument and CBCT images.

The effects of dry needling and face yoga on pain, depression, function, and sleep quality in patients with temporomandibular dysfunction

ContextTemporomandibular joint dysfunction (TMD) poses significant challenges due to its diverse symptoms and impact on patients' daily lives. ObjectiveThis study aimed to explore the effectiveness of two innovative interventions, dry needling and face yoga, in managing TMD-related issues such as pain, depression, and sleep quality. Design and study participantsNinety patients with TMD symptoms were enrolled in a prospective randomized controlled trial. The patients were divided into three groups: dry needling, face yoga, and a control group. Various assessments, including Visual Analog Scale for pain, Beck Depression Inventory for depression, and Pittsburgh Sleep Quality Index for sleep quality, were conducted before and 6 weeks after the interventions. ResultsA decrease in pain levels and a statistically significant increase in jaw joint movements (mouth opening, protrusive movement, lateral movements) were observed in the dry needling and face yoga groups after treatment (p <0.05). Additionally, improvements in sleep quality were observed (p <0.05). ConclusionDry needling and face yoga interventions demonstrated efficacy in managing TMD symptoms, including pain relief and improved jaw movement. The findings suggest that these interventions can be valuable additions to the treatment regimen for patients suffering from TMD-related issues. However, further research is warranted to explore the long-term effects and mechanisms underlying these interventions in TMD management.

Fuctional balancing in complete dentures- A case report revisiting the paterson’s technique

: A good occlusion is the key to the comfort and longevity of a prosthesis. : This case report presents a 63 year old male patient who reported with the complaint of difficulty in chewing since past 3 months.: On examination, the patient presented with completely edentulous upper and lower arch. A detailed case history was recorded followed by, primary and secondary impressions. The maxillo-mandibular relation was recorded conventionally on wax occlusal rims. A trough was then made in the wax and filled with a mixture of dental plaster and carborundum. The mix was kept 2mm above the plane. The rims were inserted and the patient was instructed to perform lateral and protrusive movements resulting in the incorporation of the compensating curves. The recorded plaster index served as a guide for the teeth arrangement. The denture was processed and delivered with very minimal need for post insertion corrections.: According to Paterson (1923), an articulator with lateral movements is not necessary to establish a balanced occlusion when using the functional technique. The teeth arrangement is entirely dependent on the established curves for obtaining balance.: Various techniques are cited throughout the literature to provide a successful prosthesis. With all the advances in the digital era, denture fabrication is not an automated procedure. It is pertinent that the clinicians master the fundamentals of prosthesis fabrication, without which any amount of technology and/or persistence might be in vain.

The Effect of Preparation Design on Stress Distribution in Lithium Disilicate Laminate Veneer using 3D Finite Element Analysis.

Background: A layer of ceramic bonded to the facial surfaces of prepared teeth to create a ceramic esthetic veneer, also known as a laminate veneer. Objective: This study aimed to examine the effect of preparation design on the stress distribution in lithium disilicate veneer at different angulations of masticatory loading. Methods: The finite element approach assessed the structure stress distribution. So, Exocad dental CAD was used to obtain the models, which consist of an upper central incisor in three dimensions (3D), and prepare them with the same software for an indirect veneer. The models were imported into software (SolidWorks; Dassault Systems) to construct solid models. The external load used in this study was 100 N at 60 degrees (intercuspal) and 125 degrees (protrusive) in the palatal surface, two mm below the incisal edge. The models were restored using e-max laminate veneers with different tooth preparation designs (palatal chamfer and window preparation designs). Analysis and calculations were performed on the stress distributions and maximum stress values of the tooth structures, cement layer, and laminate veneer. Results: With a window preparation design, the maximum stress values in the tooth and laminate veneer were higher. In the palatal chamfer design, stresses were dispersed more consistently through the cement layer and laminate veneer. Higher stress was generated by protrusive movement than by intercuspal movement. Conclusion: Compared to window preparation, the palatal chamfer design for lithium disilicate laminate veneer showed a more favourable stress distribution. Regardless of the preparation design, maximum stress values were observed in the cervical and incisor areas of the tooth structure.

The Effect of Preparation Design on Stress Distribution in Lithium Disilicate Laminate Veneer using 3D Finite Element Analysis.

Background: A layer of ceramic bonded to the facial surfaces of prepared teeth to create a ceramic esthetic veneer, also known as a laminate veneer. Objective: This study aimed to examine the effect of preparation design on the stress distribution in lithium disilicate veneer at different angulations of masticatory loading. Methods: The finite element approach assessed the structure stress distribution. So, Exocad dental CAD was used to obtain the models, which consist of an upper central incisor in three dimensions (3D), and prepare them with the same software for an indirect veneer. The models were imported into software (SolidWorks; Dassault Systems) to construct solid models. The external load used in this study was 100 N at 60 degrees (intercuspal) and 125 degrees (protrusive) in the palatal surface, two mm below the incisal edge. The models were restored using e-max laminate veneers with different tooth preparation designs (palatal chamfer and window preparation designs). Analysis and calculations were performed on the stress distributions and maximum stress values of the tooth structures, cement layer, and laminate veneer. Results: With a window preparation design, the maximum stress values in the tooth and laminate veneer were higher. In the palatal chamfer design, stresses were dispersed more consistently through the cement layer and laminate veneer. Higher stress was generated by protrusive movement than by intercuspal movement. Conclusion: Compared to window preparation, the palatal chamfer design for lithium disilicate laminate veneer showed a more favourable stress distribution. Regardless of the preparation design, maximum stress values were observed in the cervical and incisor areas of the tooth structure.

Biomechanical Implications of Mandibular Flexion on Implant-Supported Full-Arch Rehabilitations: A Systematic Literature Review.

Mandibular flexion (MF) is a complex biomechanical phenomenon, which involves a deformation of the mandible, due mainly to the contraction of the masticatory muscles, and it can have numerous clinical effects. The deformation of the lower jaw caused by mandibular flexion is generally very small, and it is often overlooked and considered irrelevant from a clinical point of view by many authors; however, it should be important to remember that median mandibular flexure (MMF) has a multifactorial aetiology. The main aim of the current systematic review is to highlight the different factors that can increase MF in order to help clinicians identify patients to whom they should pay more attention. As a secondary outcome, we wanted to analyse the preventive measures and suitable techniques to be adopted to minimise the negative effects of this phenomenon on oral fixed rehabilitations. The review, which was carried out in accordance with the "Preferred Reporting Items for Systematic reviews and Meta-Analyses" (PRISMA) flowchart, was recorded in the "International Prospective Register of Systematic Reviews" (PROSPERO). As research questions, "Patient/Population, Intervention, Comparison and Outcomes" (PICO) questions were employed. Using the ROBINS-I technique, the risk of bias in non-randomised clinical studies was evaluated. The initial electronic search identified over 1300 potential articles, of which 54 studies were included in this systematic review. Information regarding the relationship between MF and individual factors, mandibular movements, impression taking, and fixed rehabilitations were obtained. The studies included in this systematic review showed that MF is greater during protrusive movements, in the posterior areas of the lower jaw, and in patients with brachial facial type, greater jaw length; small gonial angle; and less density, length, and bone surface of the symphysis. The biomechanical effects of mandibular flexion on fixed restorations are debated. Prospective clinical and radiological observational studies should be conducted to evaluate the potential short-, medium-, and long-term consequences of MF.

The Effect of Photobiomodulation on Temporomandibular Pain and Functions in Patients With Temporomandibular Disorders: An Updated Systematic Review of the Current Randomized Controlled Trials.

Introduction: Temporomandibular disorders (TMDs) are the most prevalent non-dental origin orofacial pain conditions affecting the temporomandibular joints (TMJs) and/or orofacial muscles. Photobiomodulation therapy (PBMT) is a conservative way to improve function and reduce symptoms in TMD patients. This systematic review was conducted to update evidence about the effects of PBMT on pain intensity, TMJ movements, electromyography (EMG) activity, pressure pain threshold (PPT), and TMJ sound in patients with TMDs. Methods: A systematic literature search was conducted in Web of Science, PubMed/Medline, and Scopus databases using appropriate keywords and specific strategies from January 2000 to September 2022. Data extraction was done based on the inclusion/exclusion criteria. Results: A total of 40 studies were included. All included studies except one provided information on pain intensity; 27 studies showed a reduction in pain intensity in PBMT groups compared to control groups. Seven out of 15 studies, which reported maximum mouth opening (MMO), showed a greater MMO in PBMT groups than in placebo groups. In addition, the figures for passive maximum mouth opening (PMMO) and active maximum mouth opening (AMMO) in all the studies reporting PMMO and AMMO were higher in PBMT groups. In eight out of ten studies, lateral movement (LM) was greater in PBMT groups. Moreover, in three studies out of four, protrusive movement (PM) was reported to be greater in the PBMT group. Four out of nine studies showed a greater PPT in the PBMT group. Reduced TMJ sounds in the PBMT group were reported in two out of five studies. In addition, in most studies, no difference in EMG activity was detected between the two groups. Conclusion: This updated systematic review showed the promising effects of PBMT on the alleviation of pain and improvement in MMO. Using the infrared diode laser with a wavelength ranging between 780-980 nm, an energy density of<100 J/ cm2, and an output power of≤500 mW for at least six sessions of treatment seems to be a promising option for treating mentioned TMDs signs and symptoms based on the previously reported findings.

A Single Center Experience: A Retrospective Study Over 10-Years Period on Mandible Fractures.

The purpose of this study was to do a retrospective analysis about patients with mandibular fracture who were treated at the department of Maxillofacial Surgery, Regional University Hospital of Ancona, Italy, between 2011 and 2021. In this study we evaluated clinical and epidemiological findings of mandible fractures focusing on the association between surgical timing, type of surgical approach and mid- and long-term outcomes. Patients were evaluated based on various parameters including age, sex, etiology, symptoms, comorbidity, clinical findings, mandible fracture type, other facial fractures, treatment, waiting time before the operation, complications and sequelae. In the period described, we recorded 1023 mandibular fractures. 93% of patients underwent surgery under general anesthesia, almost exclusively patients undergoing an open approach to internal fixation. Of the patients, 684 were male (66.86%) and 339 were female (33.13%). The average age of the patients was 42, 38years (range, 7-94years). The leading cause of these fractures was traffic accidents (27.3%) and mandibular parasymphysis fractures were the most frequent (34.1%). The most common clinical signs and symptoms were malocclusion, difficulty in chewing, limitation of the buccal opening, hypoesthesia extending through the territory of the inferior alveolar nerve, difficulty in protrusion movements and mandibular lateralization. The continuous research in epidemiology, etiology, materials, and techniques will further refine the treatments of mandible fractures, which are nowadays more and more customized according to the type of trauma.

Intraindividual Left-Right Side Differences of Sagittal Condylar Inclination (SCI) in Different Skeletal Classes.

(1) Background: The temporomandibular joint (TMJ) is the most complex and one of the most important joints in the human body due to its essential roles in mastication, swallowing, breathing and speech. Several instruments have been used to track mandibular movements and register the characteristic parameters of the TMJ, among which condylography instruments are validated for the accurate clinical registration of the condylar path. Sagittal condylar inclination (SCI) is one of the most important parameters, together with the Bennett angle and the immediate side shift, used for articular settings in the process of oral rehabilitation. The aim of the present study was to evaluate the differences between the left and right SCI and to assess whether the differences were statistically significant for skeletal class, age, gender, dentate status, TMJ pathology or parafunctional habits. (2) Methods: One hundred and forty consecutive patients, fully dentate or partially edentulous, and with angle class I, II and II, were recruited. Their left and right SCIs were determined with an ultrasonic jaw tracking device. Each subject had to make three protrusive movements and three right and left laterotrusive movements. The software calculated the SCI from the mean of the protrusive movements. (3) Results: The mean values obtained for the right and left SCI were 34.68° (±12.44°) and 34.94° (±13.23°), respectively, with no statistically significant differences between the left and right values for gender, dentate status, TMJ disorders or parafunctional habits. Skeletal class III subjects registered lower SCI means, which were statistically significant for the left SCI. (4) Conclusions: For an optimal functionalization of prosthetic restorations and for an ideal treatment plan, the registration of both the left and right paths of the condyles and the articular disc should be taken into consideration.

A comparative analysis between intra articular injections of injectable platelet rich fibrin versus platelet rich plasma in the management of temporomandibular disorders: A randomized control trial.

Platelet concentrate has become an increasingly popular alternative source of growth factors for several types of dental and surgical procedures. It improves healing and stimulates cell proliferation, matrix remodeling, and angiogenesis. The injectable platelet-rich fibrin (i-PRF) has various advantages over platelet-rich plasma (PRP). The aim of our study was to evaluate the efficacy of intra-articular injections of i-PRF versus PRP in the management of temporomandibular disorders (TDMs). The prospective randomized study involved 14 patients (N = 28 joints) of internal derangement between the age groups of 20 to 50 years divided randomly into two groups with seven patients (N = 14 joints) in each group. For all the patients, arthrocentesis was carried out in the first sitting followed by intra-articular injections of PRP and i-PRF in group I and group II, respectively, at 1-month interval for 6 months. A single surgeon has performed the procedure. All patients were assessed clinically for pain, maximal mouth opening (MMO), lateral movement, protrusive movement, and joint sounds and radiographically for disc position and joint effusion (JE). Pain reduction, MMO, lateral movement, protrusive movement, and joint sounds were significant in both groups with more significance in group II. Disc position had improved toward normal in both groups and showed significant changes in both groups at the 9-month follow-up with better results in group II. PRP and i-PRF injections are regarded as simple and safe methods with potential beneficial effects and are cost-effective. In this preliminary study, i-PRF has been found to be scoring better in terms of efficacy over PRP across all set parameters.

THREE-DIMENSIONAL KINEMATICS OF THE JAW FOLLOWING UNILATERAL AND BILATERAL PROSTHETIC TMJ SURGERY

Total temporomandibular joint (TMJ) replacements reduce pain and improve quality of life in patients suffering from end-stage TMJ disorders, such as osteoarthritis and trauma. Jaw kinematics measurements following TMJ arthroplasty provide a basis for evaluating implant performance and jaw function. The aim of this study is to provide the first measurements of three-dimensional kinematics of the jaw in patients following unilateral and bilateral prosthetic TMJ surgeries.Jaw motion tracking experiments were performed on 7 healthy control participants, 3 unilateral and 1 bilateral TMJ replacement patients. Custom-made mouthpieces were manufactured for each participant's mandibular and maxillary teeth, with each supporting three retroreflective markers anterior to the participant's lip line. Participants performed 15 trials each of maximum jaw opening, lateral and protrusive movements. Marker trajectories were simultaneously measured using an optoelectronic tracking system. Laser scans taken of each dental plate, together with CT scans of each patient, were used to register the plate position to each participant's jaw geometry, allowing 3D condylar motion to be quantified from the marker trajectories.The maximum mouth opening capacity of joint replacement patients was comparable to healthy controls with average incisal inferior translations of 37.5mm, 38.4mm and 33.6mm for the controls, unilateral and bilateral joint replacement patients respectively. During mouth opening the maximum anterior translation of prosthetic condyles was 2.4mm, compared to 10.6mm for controls. Prosthetic condyles had limited anterior motion compared to natural condyles, in unilateral patients this resulted in asymmetric opening and protrusive movements and the capacity to laterally move their jaw towards their pathological side only. For the bilateral patient, protrusive and lateral jaw movement capacity was minimal.Total TMJ replacement surgery facilitates normal mouth opening capacity and lateral and inferior condylar movements but limits anterior condylar motion. This study provides future direction for TMJ implant design.

Does the Use of Injectable Platelet-Rich Fibrin After Arthrocentesis for Disc Displacement Without Reduction Improve Clinical Outcomes?

Many studies have reported the role of arthrocentesis to alleviate symptoms in patients with disc displacement without reduction (DDWoR). Nevertheless, the benefit of injectable platelet-rich fibrin (i-PRF) remains unclear. The aim of this study was to answer the following question: Among patients with DDWoR, do those treated with intra-articular injection of i-PRF after arthrocentesis, when compared to those treated with arthrocentesis only, have better clinical outcomes in terms of pain reduction and improvement of jaw movement? This single-blind randomized, controlled study included patients with diagnosed DDWoR, in the Department of Oral and Maxillofacial Surgery at the School of Dentistry, Ege University, who had localized joint pain and limited range of motion. Patients were treated either with arthrocentesis (AC group) or arthrocentesis in combination with intra-articular i-PRF injection (AC+i-PRF group). The predictor variable was treatment (ie, arthrocentesis with or without i-PRF). The primary outcome variable was pain (visual analog scale). The secondary outcome variables were maximum mouth opening, lateral and protrusive movements. Outcome variables were recorded at pretreatment and at the postoperative 1st, 2nd, 3rd, 6th, and 12th months. Statistical analysis was performed using the Brunner-Langer model, with a significance level P<.05. This study comprised 76 patients (34 females/4 males, mean age 47.2±9.1 for the AC+i-PRF group; 35 females/3 males, mean age 46.8±10.2 for the AC group). The treatment success rate was 73.7% for the AC group and 100% for the AC+i-PRF group (P=.012). Pain levels in the AC+i-PRF group were found to decrease more than the AC group over 12months postoperatively (palpation: -6.9±1.2 vs -5.3±1.3; chewing: -6.9±1.5 vs -5.1±1.7; jaw movements: -6.9±1.1 vs -5.1±1.4). This difference was statistically significant (P<.001). The degree of jaw movement in the AC+i-PRF group was found to increase more than the AC group over 12months postoperatively (maximum mouth opening: 8.0±2.1 vs 4.9±2.0; contralateral: 1.8±0.8 vs 0.2±1.0; ipsilateral: 2.9±1.3 vs 0.8±1.5; protrusive: 2.6±1.1 vs 0.8±1.3). This difference was statistically significant (P<.001). Intra-articular injection of i-PRF after arthrocentesis produced greater improvements in pain reduction and jaw movement when compared to arthrocentesis only. These results indicate that i-PRF used in combination with arthrocentesis is an effective adjunctive treatment.

Outcome of Management of Mandibular Sub condylar Fractures Based on Classification System Using Cone-Beam Computed Tomography.

The purpose of this study is to determine the amount of ramal height shortening and degree of displacement of sub condylar fracture that should be considered for effective management of mandibular sub condylar fractures using cone-beam computed tomography. A prospective study of forty-two patients, who presented with unilateral sub condylar fracture was done. All patients were classified into Class I, II and III based on the degree of displacement of fractured segment and amount of ramal height shortening measured using cone-beam computed tomography. The treatment protocol was closed reduction and maxillomandibular fixation for Class I patients and open reduction and internal fixation for Class II and III patients. Outcomes of treatment were measured postoperatively 2weeks, 1 and 3months clinically. The variables, such as mouth opening, lateral and protrusive movements, deviation, pain and occlusion were studied. Among forty-two patients, twenty had Class I fractures, twelve had Class II fractures and ten had Class III fractures. Overall, no statistically significant differences were found between Class I and Class II groups in terms of functional outcomes and there were statistically significant differences between Class I and III groups. Class I fractures can be considered for closed method and open reduction is recommended for Class II and III fractures. The sample was composed of 42 patients grouped as follows: Class I (n = 20), Class II (n = 12), and Class III (n = 10) for treatment of sub condylar fractures. There were no significant differences between the three groups for the study variables at baseline, except for mouth opening and pain. There was significant difference in mouth opening between Class I and III cases (p 0.001) and insignificant difference in mouth opening in Class I and II cases (p 0.98). Persistent pain was elicited more in surgical Class II and III (n = 5) than non-surgical cases Class I (n = 0) on 3months follow-up. The study emphasises on use of three-dimensional diagnostic modality like cone-beam computed tomography for accurately classifying sub condylar fractures. The results favour closed reduction for mildly displaced Class I cases and surgical management of significantly displaced Class III fractures. The need for open reduction for Class II patients classified using CBCT is negligible assessing risks associated with surgical procedure which is contradictory to our protocol which requires a further comparative evaluation among Class II group.

Aspects of Dental Occlusion Assessed with the T-Scan System among a Group of Romanian Dental Students in a Cross-Sectional Study.

This study evaluated the occlusal relationships in students with bruxism, using the T-Scan III system, and their correlation with the activity of the masticatory muscles assessed through surface electromyography (sEMG). The study group was divided into two subgroups (based on self-reporting): 20 participants with possible bruxism and 20 participants without possible bruxism; all participants underwent the following evaluations: sEMG recordings using the dia-BRUXO device for masticatory muscles assessment, as well as static and dynamic occlusion using the T-SCAN III system. The analysis of the maximum intercuspidal (MI) position revealed a positive moderate association between the values of the occlusal forces in MI distributed along the two hemiarches, and the number of grinding events during daytime, which was statistically significant (p < 0.05). The analysis of protrusion movements reflected statistically significant differences between the non-working interferences and sEMG parameters specific to bruxism (p < 0.05). The analysis of laterotrusion movements indicated that participants with anterolateral guidance presented higher values of awake bruxism indexes and higher values of clenching events during nighttime. For all three mandibular movements, their duration was higher for the study group compared to the control group. Therefore, this study confirmed the utility of sEMG recordings in the bruxism diagnosis process, as well as the association between dental occlusion and bruxism.