Occlusal Plate Research Articles

Influence on the temporomandibular joint induced by mandibular malpositioning caused by vertical dimension elevation and occlusal loss in adult rats: An imaging, histological and immunohistochemical study.

Mandibular malpositioning may result in an abnormal concentration of stresses within the temporomandibular joint (TMJ) in adult rats, which may further lead to a series of pathological changes, such as articular cartilage wear, subchondral bone sclerosis and osteophyte formation. However, the pathological and adaptive changes in condylar cartilage caused by different stress distributions are still controversial. The aim of this study was to observe the effect of sagittal changes in mandibular position on condylar cartilage by changing the occlusal vertical dimension (OVD) in adult rats. Fifteen-week-old female rats were divided into three groups: control (CON), increased OVD (iOVD) and loss of occlusion (LO) groups. An occlusal plate and tooth extraction were used to establish the animal model. TMJ samples of the experimental and CON groups were observed and investigated by bone morphological, histomorphological and immunohistochemical staining analyses at 3 days, 1 week, 2 weeks, 4 weeks and 8 weeks. Weight curves were plotted. Micro-computed tomography showed that, compared with the CON group, cartilage destruction followed by repair occurred in both experimental groups, which was similar to the trend observed in haematoxylin-eosin staining. All experimental results for the iOVD group showed an approximately similar time trend. Compared with the iOVD group, the toluidine blue and immunohistochemical staining results in the LO group showed no obvious change trend over time. Compared with occlusal loss, an increase in OVD caused faster and more severe damage to condylar cartilage, and subchondral bone repair occurred later.

Developing and Validating an Intelligent Mouth-Opening Training Device: A New Solution for Restricted Mouth Opening.

Restricted mouth opening (trismus) is one of the most common complications following head and neck cancer treatment. Early initiation of mouth-opening exercises is crucial for preventing or minimizing trismus. Current methods for these exercises predominantly involve finger exercises and traditional mouth-opening training devices. Our research group successfully designed an intelligent mouth-opening training device (IMOTD) that addresses the limitations of traditional home training methods, including the inability to quantify mouth-opening exercises, a lack of guided training resulting in temporomandibular joint injuries, and poor training continuity leading to poor training effect. For this device, an interactive remote guidance mode is introduced to address these concerns. The device was designed with a focus on the safety and effectiveness of medical devices. The accuracy of the training data was verified through piezoelectric sensor calibration. Through mechanical analysis, the stress points of the structure were identified, and finite element analysis of the connecting rod and the occlusal plate connection structure was conducted to ensure the safety of the device. The findings support the effectiveness of the intelligent device in rehabilitation through preclinical experiments when compared with conventional mouth-opening training methods. This intelligent device facilitates the quantification and visualization of mouth-opening training indicators, ensuring both the comfort and safety of the training process. Additionally, it enables remote supervision and guidance for patient training, thereby enhancing patient compliance and ultimately ensuring the effectiveness of mouth-opening exercises.

Precise minimally invasive treatment of mandibular fracture in children assisted by digital surgery technology

Objective: To explore the role of digital three-dimensional printing technology and multifunctional board in the treatment of mandibular fracture in children. Methods: From January 2006 to January 2022, 42 children with mandibular fracture were treated by Department of Stomatology, in The First Affiliated Hospital of Bengbu Medical College, including 25 males and 17 females. The patients, aged from 4 to 12 years, with the median age was 10 years old, were divided into observation group (22 cases) and routine group (20 cases) according to the treatment methods. In the observation group, the multifunctional board was made before operation, and the CT data of the children were imported into Mimics software in".dicom"format, and the displaced mandible was virtually reset. The jaw reduction model was made by three-dimensional printing, and the surgical operation was simulated on the reduction model to determine the model and position of the internal fixation device and shape it. During the operation, the fracture was reduced and fixed according to the preoperative design; The conventional group was treated with open reduction and internal fixation of mandibular fracture by traditional methods, and the clinical application value was compared and analyzed through the intraoperative situation, occlusal relationship, and follow-up of the two groups. Results: The total intraoperative bleeding volume [(30.25±4.02) ml] and surgical time [(64.3±9.2) min] in the observation group were significantly lower than those in the conventional group [(35.13±5.69) ml and (84.6±13.9) min, respectively] (F=6.18, P=0.003; F=1.32, P=0.001). The excellent and good rate of occlusal relationship in the observation group [96% (21/22)] was significantly higher than that in the conventional group [85% (17/20)] (F=4.27, P=0.039). The incidence of complications, the observation group, 1 case of poor occlusion, 1 case of postoperative infection; In the routine group, there were 3 cases with poor occlusion, 1 case with nerve injury, 1 case with root injury and 1 case with tooth germ injury. Conclusions: The application of digitization three-dimensional printing technology combined with multifunctional occlusal plate in children's mandibular fracture is minimally invasive, safe, efficient and accurate, and the clinical effect is good.

Evaluation of the mechanical properties of different materials for manufacturing occlusal splints.

This study aimed to compare the mechanical properties of various occlusal plate materials by analyzing surface roughness, Knoop microhardness, flexural strength, and modulus of elasticity. Fifty samples were prepared and classified as SC (self-curing acrylic resin), WB (heat-cured acrylic resin), ME (acrylic resin polymerized by microwave energy), P (resin print), and M (polymethylmethacrylate polymer block for computer-aided design/computer-aided manufacturing). The data were analyzed using a one-way analysis of variance and Tukey's honestly significant difference test. Surface roughness was the same in all groups. The surface hardness of group M was statistically superior. The samples from groups P and M had higher flexural strength than other samples. The modulus of elasticity of group SC was statistically lower than that of other groups. The mechanical properties of the materials used to make the occlusal plates differed, and group M achieved the best results in all analyses. Therefore, clinicians must consider the material used to manufacture long-lasting and efficient occlusal splints.

Dynamic 3D images fusion of the temporomandibular joints: A novel technique

ObjectivesTo demonstrate a procedure for fusing images from cone-beam computed tomography (CBCT), magnetic resonance imaging (MRI) and optical positioning tracking system to dynamically evaluate the relative motion of the temporomandibular joint (TMJ) for the diagnosis of temporomandibular disorders (TMD). MethodsCBCT data was collected from a patient wearing a fixation device with markers in the intercuspal position. The patient's mandibular movements were recorded using an optical positioning tracking system. The CBCT data were imported into a virtual simulation system to reproduce the mandibular movement. Five jaw positions were selected for 3D printing of the occlusal plate that the patient wore to undergo MRI. MRI scans were registered with the CBCT image for fusion and reconstruction. ResultsThe anatomical structures of the articular fossa, articular disc, and condyle were clearly displayed in the CBCT-MRI fused images. The spatial posture and relative position of the fossa-disc-condyle during mandibular movement could be reproduced dynamically using the 3D reconstruction model. ConclusionsThis method can visually display mandibular motion trajectories and the relative TMJ positions. Virtual reproduction provides a comprehensive understanding of the articular disc's morphology and position in different states from a 3D perspective. Clinical SignificanceThis method can be used in clinical studies of TMJ as an adjunct to the 3D dynamic diagnosis and assessment for complex patients with TMD and provide relevant data for doctors.

\u201cMultidisciplinary management of post- infective osteoarthritis and secondary condylar resorption of temporomandibular joint: a case report in a 9\u2009years-old female patient and a review of literature\u201d

BackgroundOsteoarthritis and condylar resorption of temporomandibular joint (TMJ) has rarely been reported in children as consequence of otologic disease. We describe the management of a case in a 9-year-old female as long-term complication of an otomastoiditis and review the literature currently available on this topic.Case presentationA nine-years-old female patient referred to Emergency Room of Bambino Gesù Children’s Research Hospital, IRCCS (Rome,Italy) for an acute pain in the left preauricular area and reduced mandibular movements. In the medical history an otomastoiditis and periorbital cellulitis was reported at the age of six with complete remission of symptoms after antibiotic treatment. No recent history of facial trauma and no previous orthodontic treatment were reported. She was referred to a pediatric dentist that conducted a clinical examination according to the Diagnostic Criteria of Temporomandibular Disorders (DC/TMD) and was diagnosed with bilateral myalgia of the masticatory muscles and arthralgia at the level of the left TMJ. Then, a complete diagnostic path was performed that included multidisciplinary examinations by a rheumatologist, infectious disease specialist, ear nose and throat (ENT) doctor, a maxillofacial surgeon and a medical imaging specialist. Differential diagnosis included juvenile idiopathic arthritis, idiopathic condylar resorption, trauma, degenerative joint disease, neurological disease. Finally, unilateral post-infective osteoarthritis of the left TMJ with resorption of mandibular condyle was diagnosed. The patient went through a pharmacological therapy with paracetamol associated to counselling, jaw exercises and occlusal bite plate. After 1 month, the patient showed significant reduction of orofacial pain and functional recovery that was confirmed also one-year post-treatment. The novelty of this clinical case lies in the accurate description of the multidisciplinary approach with clinical examination, the differential diagnosis process and the management of TMD with conservative treatment in a growing patient.ConclusionsSeptic arthritis of temporomandibular joint and condylar resorption were described as complications of acute otitis media and/or otomastoiditis in children. We evidenced the importance of long-term follow-up in children with acute media otitis or otomastoiditis due to the onset of TMJ diseases. Furthermore, in the multidisciplinary management of orofacial pain the role of pediatric dentist is crucial for the diagnostic and therapeutic pathway to avoid serious impairment of mandibular function.

Establishment of a novel method for qualitative and quantitative evaluation of deglutitive tongue movement by integration of ultrasound video imaging and lateral cephalogram

ABSTRACT Purpose: To establish a novel method for qualitative and quantitative evaluation of deglutitive tongue movement by integration of ultrasound (US) video imaging and lateral cephalogram of mandibular prognathism subjects before and after orthognathic surgery. Materials and methods: The US video imaging and lateral cephalogram were obtained from ten mandibular prognathism subjects before and after orthognathic surgery and integrated with an acrylic positional occlusal plate (POP) as a marker for superimposition. The percentage of the anterior and posterior tongue dorsum height, with respect to the palatal height, was measured and compared at each stage (Stages 1–5) of the deglutitive tongue movement. Individual variation on 5-times repeated deglutitive tongue movement in the same subject was evaluated. Furthermore, the intra- and inter-examiner reliability was evaluated using Dahlberg’s formula and correlation coefficient. Results: The individual variation value was small enough, while the intra-examiner measurement errors were all < 0.20 and the inter-examiner correlation coefficient values were all > 0.80. The percentage of the posterior tongue dorsum height in the postoperative measurement was significantly larger than that measured preoperatively at all deglutitive stages, except Stage 4. In seven out of ten subjects, the tongue tip region protruded over the upper incisor edge before surgery could touch the lingual surface of the upper incisor postoperatively. Conclusion: The newly developed US-cephalogram integration method was useful for qualitative and quantitative evaluation of the deglutitive tongue movement in a clinical setting without additional radiation exposure.

Influence of Flat Occlusal Splint on Stresses Induced on Implants for Different Fixed Prosthetic Systems.

The flat occlusal plate has been recommended to reduce stress concentration in implant prosthesis treatments. The purpose was to investigate the influence of the occlusal splint on three-element implant-supported fixed prosthesis. A three-dimensional virtual model was created consisting of a cortical and spongy bone block simulating the region from first premolar to the maxillary first molar using two HE or MT implants (4 x 11mm) with Ti and/or Y-TZP abutments. The second premolar was the pontic of the prosthesis. The three-element fixed prosthesis with a zirconia infrastructure and Y-TZP coating were cemented, in addition to using a flat occlusal splint made of acrylic resin in the region. Combined axial and oblique loads of 100N and 300N were applied. The tensile stresses on MT implant bone tissue produced values of 4-19% lower than those of HE implants. The lowest differences were observed for oblique loading with an occlusal splint, with a 4% (Ti-Y-TZP) and 9% (Ti-Ti) decrease. When the compressive stresses were evaluated, HE implants produced lower values than MT implants. A significant increase was observed in the oblique loading stresses in the absence of occlusal splints, regardless of the applied load.

CIRCULATION IN STUMP OF BONE AT VARIOUS METHODS OF AMPUTATION PLASTICS

The purpose of the study was to determine the most effective methods of amputation plasty, which provide adequate blood circulation in the bone stump. Three series of experiments were performed on 75 dogs with closure of the sawdust with myodesis, a combination of myodesis with bone plasty with a thin cortical plate taken from the part of the limb to be removed (main groups), fascioplastic and myoplastic, with the cross-linking of the antagonist muscles under the sawdust (control group). The observation period was1, 3, 8 months. The advantage of dense closure of the medullary cavity with the help of myodesis and its combination with bone plasticity by a thin cortical plate has been proved. Restoration of intraosseous pressure disturbed during amputation during a month period occurs only with myodesis with tight closure of muscles and bone plastic with a thin cortical plate tightly laid at the edge of the open bone marrow cavity. With fascio- and myoplasty in the next time (1–3 months), it is low, and in the distant (8 months) – high, due to pronounced venous stasis. Restoration of the impaired closure of the medullary cavity is achieved already during the operation, which ensures complete compression of the lumen of the feeding artery along with the venous sinus, and rapid formation of the osseous occlusal plate with restoration of normal intraosseous circulation. With fascio- and myoplastic amputation, incomplete closure of the medullary canal with tissues is an obstacle to powerful blood flow along the intraosteal main vessels, which under its influence become convoluted and form vascular conglomerates. The latter, occupying the lumen of the medullary canal, create a mechanical obstacle to the restoration of the closed bone marrow cavity necessary for normalization of intraosseous microcirculation.

CIRCULATION IN STUMP OF BONE AT VARIOUS METHODS OF AMPUTATION PLASTICS

The purpose of the study was to determine the most effective methods of amputation plasty, which provide adequate blood circulation in the bone stump. Three series of experiments were performed on 75 dogs with closure of the sawdust with myodesis, a combination of myodesis with bone plasty with a thin cortical plate taken from the part of the limb to be removed (main groups), fascioplastic and myoplastic, with the cross-linking of the antagonist muscles under the sawdust (control group). The observation period was1, 3, 8 months. The advantage of dense closure of the medullary cavity with the help of myodesis and its combination with bone plasticity by a thin cortical plate has been proved. Restoration of intraosseous pressure disturbed during amputation during a month period occurs only with myodesis with tight closure of muscles and bone plastic with a thin cortical plate tightly laid at the edge of the open bone marrow cavity. With fascio- and myoplasty in the next time (1–3 months), it is low, and in the distant (8 months) – high, due to pronounced venous stasis. Restoration of the impaired closure of the medullary cavity is achieved already during the operation, which ensures complete compression of the lumen of the feeding artery along with the venous sinus, and rapid formation of the osseous occlusal plate with restoration of normal intraosseous circulation. With fascio- and myoplastic amputation, incomplete closure of the medullary canal with tissues is an obstacle to powerful blood flow along the intraosteal main vessels, which under its influence become convoluted and form vascular conglomerates. The latter, occupying the lumen of the medullary canal, create a mechanical obstacle to the restoration of the closed bone marrow cavity necessary for normalization of intraosseous microcirculation.

Increased crown-to-implant ratio may not be a risk factor for dental implant failure under appropriate plaque control.

ObjectiveThe aim of this study was to evaluate whether increased crown-to-implant (C/I) ratio influences implant stability or not under proper healthy control of peri-implant mucosa. The hypothesis of this study is that implant stability can be maintained despite High C/I, under appropriate plaque control.Materials and MethodsFive male Beagle-Labrador hybrid dogs (2 years old) were used. Their bilateral mandibular premolar extraction was performed. After allowing 12 weeks for bone healing, 3 types of vertical marginal bone loss were simultaneously prepared randomly. Then, 30 titanium implants were placed in the edentulous areas and defined as High C/I, Mid C/I and Low C/I groups. This time point was designated as the baseline (0 Week). Twelve weeks after implant placement, metal superstructures were cemented to the implants and an occlusal plate was set at the opposite side. At the same time, Calcein green was injected for remodeling evaluation. Implants were loaded by feeding the dogs a hard pellet diet. Tooth brushing was performed 5 days per week during the study to maintain healthy peri-implant mucosa. Twenty-four weeks following implant placement, the interface structure was evaluated clinically, radiologically, and histologically.ResultImplant stability quotient (ISQ) increased with time in all 3 groups, without any significant correlation with the C/I value (p >0.05). Moreover, mean marginal bone loss adjacent around implants in all 3 groups ranged between 0.11 and 0.19 mm, with no significant difference (p >0.05). Many fluorescence-labeled bones are shown in the High C/I group. It is considered that high remodeling activity prevent marginal bone loss in the High C/I group and this may provide favorable implant stability under proper plaque control.ConclusionThese findings suggest that increased C/I may not be a risk factor for implant failure if the peri-implant mucosa is kept healthy, as was the case in this animal model.

Established prosthodontic rules confirmed in natural adolescent occlusion

Guidelines have been established for the arrangement of artificial teeth based on the curve of Wilson, the curve of Spee and the occlusal plate rule of Gysi. However, no scientific studies have been carried out to see whether these prosthodontic rules are actually present in natural teeth. This study was carried out on a selected sample of children and adolescents with natural dentitions using a 3D computer-aided measuring device to reevaluate these occlusal rules in order to establish whether occlusion with anterior protected articulation is the occlusal scheme of choice. The previously estblished prosthodontic rules were confirmed to be present in the complete natural dentitions of adolescents at completion of tooth eruption period and support their use as guiding principles in diagnosis and treatment.

Effective treatment of self‐injurious oral trauma in Lesch–Nyhan syndrome: a case report

Lesch-Nyhan syndrome (LNS) is an X-linked disorder originating from deficiency of the enzyme hypoxanthine guanine phosphoribosyl transferase. It is characterized by neurological manifestations, including the dramatic symptom of compulsive self-mutilation, which results in destruction of oral and perioral tissues. Several drug trials have been administered to improve the severe self-destructive behaviour, with questionable effectiveness. Invasive treatment approaches, such as extraction of teeth and orthognathic surgery, have been suggested with variable success. A conservative treatment with an intraoral appliance serving to prevent oral and peri-oral self-injury is presented in this report. The patient was a 14-year-old boy demonstrating the typical LNS behaviour, including compulsive self-biting, significant loss of lip and tongue tissue, spasticity and involuntary movements. An acrylic maxillary appliance was designed and constructed with an occlusal plate raising the bite. The appliance was retained by two Adams' clasps on the first premolars, along with three ball clasps between the incisors. Fabrication, insertion, and maintenance were uncomplicated and non-stressful to the patient. Periodic recall over 3-year period has confirmed the effective healing of the oral lesions and a high level of tolerance of the appliance.

The biteplate facebow: a clinical and cephalometric study

Introduction: The biteplate facebow includes a metallic occlusal plate that rests between the upper and lower incisors that is designed to correct the incisal overbite. The objective of this study is to evaluate the skeletal and dental effects of this appliance.

Effects of the thickness of occlusal plate and clenching pattern on the modulation of soleus H-reflex

Effects of the thickness of occlusal plate and clenching pattern on the modulation of soleus H-reflex

The Effect of Bilateral Lingual Nerve Anesthesia and Increased Occlusal Vertical Dimension on the Onset of Swallowing in Adult Males

The present study attempts to determine whether the onset of swallowing is affected by bilateral lingual and inferior alveolar nerve anesthesia and by raising the occlusal vertical dimension by wearing an occlusal bite plate. Twenty young male volunteers were selected and asked to chew and swallow corned beef and a corned beef and liquid mixture in their usual manner before and after modifications were made. Oral and pharyngeal swallowing was investigated using videofluoroscopic examination in the lateral plane. Eight objective indicators, including oral containment time, swallowing threshold, and pharynx-to-swallow intervals were estimated. Oral containment time, total sequence duration, total number of chews, and total number of swallows of the two test foods were significantly different before and after the modifications. Individual pharynx-to-swallow intervals also varied. The results indicate that modification of the masticatory condition affects the onset of swallowing and that changes in the onset varied among the participants.

２人乗り自転車前転事故による小児顎関節突起完全骨折の２例

We report on two children with infantile condylar fractures, caused by falling from front child seats of bicycles.Patient 1 was a 5-year-old boy, and patient 2 was a 2-year-old boy. Both patients had fractures of the mandible with complete condylar fractures. The first patient had a complete left fracture, and the second patient had complete right and incomplete left fractures.Circumferential wiring with an occlusal plate was performed for fixation of the mandibular body fractures, and mouth opening exercises were started several days after wiring. The occlusal plate was extremely useful, but many potential problems, such as caries or tooth luxation, were considered in patient 1.These patients show that a child riding in a front child seat of a bicycle can sustain a hard blow to the face, head, or both in the event of an accident. Increased external force due to the mother's weight can increase the severity of fractures.

THE EFFECT OF THE MOUTHPIECE ON SWIMMING

1251 It has been reported that players in several sports improve physical capabilities when they use a mouthpiece during their performance. However, the conventional mouthpiece had problems such as discomforts, swallowing depressions and speaking difficulties and there was few report using mouthpiece during swimming. We have devised a mouth piece (soft occlusal plate: SOP) which addresses these problems. We selected polyolefin-based thermoplastic elastomer which has appropriate strength and elasticity as a basic material for a custom made full mouth type mouthpiece. To determine the effects of the SOP, we evaluated swimming performances with or without the SOP. The subjects were fourteen college swimmers. Their age was 20.1 ± 0.10 yr, standing height was 165.0 ± 5.59 cm, body weight was 60.1 ± 6.94 kg. Each subject was informed of the purpose of this study and procedure and their consent was obtained. A set of 15 repeated 100 m free style swims, push-off glide distance from the wall, hand-in distance (entry point length from starting line) and start reaction time with or without the SOP were measured. The mean swimming time was significantly difference between with SOP (75.4 ± 2.09 sec) and without SOP (76.5 ± 2.67 sec). Push-off glide distance and hand-in distance with SOP (8.44 ± 0.75 m, 2.95 ± 0.16 m) was significantly longer than those of without SOP (8.07 ± 0.59 m, 2.89 ± 0.18 m). The start reaction time was 0.87 ± 0.07 sec with SOP and 0.87 ± 0.11 sec without SOP, the differences between conditions was not significant. The use of the SOP resulted in improved speed and decreased resistive force, probably due to the increased muscular strength and maintaining an ideal stream line.

新しいコンセプトによるプロビジョナル・レストレーションを活用したシステムRAPCOシステムについて第一報

This method is to systematize the process flow which is from clinical side to technical work by built in a provisional restoration with new concept. The provisional restoration with new concept has an unique feature that is given an occlusal criteria proposed by Hobo, Takayama et al, beside providing an individual teeth tray worked on the working model, in addition to the concept of the conventional provisonal restoration.The provisional restoration with new concept is called “The Particular restoration” hereafter. It's written concretely and briefly as follows.After precise impression, the particular restoration which meets an occlusal criteria suggested by Hobo et al is made and installed in the oral cavity. It is taken out from oral cavity after it is established the occulsion functioually and a patient's agreement is recieved. Then the duplicate is made. Its duplicate is tentatively installed in the oral cavity, the particular restoration is attached occlusion impression as an ideal individual teeth tray and is utilized on the working model.After all, impression, occlusion taking and check bite are obtained as almost same condition as restoration works functional status in the oral cavity and the functional condition of occlusal plate can be transfered to the final restoration changed with wax by being the particular restoration through the core of occlusal plate.The method described above is named “RAPCO system” which is abbreviation of Restoration with acquired proper condition after occlusion system.

こう合と顎関節に関する研究 Ｖ こう合挙上装置装着によるか頭位の変化について

こう合と顎関節に関する研究 Ｖ こう合挙上装置装着によるか頭位の変化について