Is there a benefit of using an arbitrary facebow for the fabrication of a stabilization appliance?

PURPOSE: The aim of this clinical study was to evaluate if an arbitrary facebow registration and transfer provides significant advantages for the fabrication of an occlusal appliance in comparison with the omission of such a procedure. MATERIALS AND METHODS: For 20 fully dentate adult patients diagnosed with bruxism, two Michigan occlusal splints were constructed. One of the two upper dental casts was transferred to the articulator with an arbitrary earpiece facebow; the other maxillary cast was mounted arbitrarily using a flat occlusal plane indicator. Upon splint delivery, the number of intraoral occlusal contacts and the time needed for chairside occlusal adjustment were recorded. RESULTS: The number of occlusal contacts on the appliance fabricated with or without facebow was similar in most cases both in the articulator and in the mouth. The one-sided Wilcoxon rank sum test showed with high probability that the use of an arbitrary facebow does not yield a clinically relevant improvement with regard to the number of occlusal contacts or the chairside adjustment time. CONCLUSION: From this pilot study, it appears that for the fabrication of an occlusal appliance, registration and transfer with an arbitrary earpiece facebow does not yield clinically relevant benefits. Of course, this conclusion cannot be transferred to other facebows and is restricted to the levels of clinical relevance defined in the study.     

How adjustment could affect internal and marginal adaptation of CAD/CAM crowns made with different materials

PURPOSERecently introduced hybrid and reinforced glass ceramic computer-aided design/computer-aided manufacturing (CAD/CAM) materials have been used for full-coverage restorations. However; the effect of adjustment and type of materials on internal and marginal adaptation are unknown. This study aimed to evaluate and compare the marginal and internal adaptations of crowns made of three different CAD/CAM materials before and after adjustment.MATERIALS AND METHODSOne acrylic resin maxillary first molar was prepared and served as the master die. Thirty-six restorations were fabricated using CAD/CAM system (CEREC Omnicam, MCXL) with three materials including lithium disilicate (IPS e.max CAD), zirconia-reinforced lithium silicate (Suprinity), and hybrid ceramic (Enamic). Internal and marginal adaptations were evaluated with the reference point matching technique before and after adjustment. The data were analyzed using mixed ANOVA considering α=.05 as the significance level.RESULTSThe effect of adjustment and its interaction with the restoration material were significant for marginal, absolute marginal, and occlusal discrepancies (P<.05). Before adjustment, Suprinity had lower marginal discrepancies than IPS e.max CAD (P=.18) and Enamic (P=.021); though no significant differences existed after adjustment.CONCLUSIONWithin the limitations of this study, crowns fabricated from IPS e.max CAD and Suprinity resulted in slightly better adaptation compared with Enamic crowns before adjustment. However, marginal, axial, and occlusal discrepancies were similar among all materials after the adjustment.     

Effects of jaw clenching while wearing an occlusal splint on awareness of tiredness,bite force,and EEG power spectrum

PurposeTreatment with an occlusal splint is used for temporomandibular disorders, bruxism, and occlusal disturbance to relieve orofacial symptoms such as myofascial pain and jaw movement restriction. However, the effects of various types of occlusal splints have not been elucidated. We investigated the effects of jaw clenching with soft and hard occlusal splints on the awareness of tiredness, bite force, and EEG activity.MethodsSix healthy adults were used as subjects, with a visual analogue scale utilized to evaluate the awareness of each patient's tiredness both preceding the session and following the clenching trials. In addition, a Dental Prescale was used to measure bite force and an EEG recording was conducted while performing jaw clenching. The jaw clenching task comprised 1 min of maximal voluntary clenching under 3 kinds of clenching conditions: with natural dentition, and with soft and hard occlusal splints, which were each repeated 5 times.ResultsJaw clenching with natural dentition and a hard occlusal splint did not cause a significant awareness of tiredness following repetitive jaw clenching, and there was not a significant alteration of EEG spectrum values with those conditions. In contrast, jaw clenching with a soft occlusal splint caused a significant increase in awareness of tiredness, as well as significant decreases in bite force and EEG alpha 2 power spectrum values.ConclusionsJaw clenching with a soft resilient occlusal splint causes an awareness of tiredness, which might be accompanied by declines in bite force and EEG spectrum values.     

Effect of occlusal splints on the electromyographic activities of masseter and temporal muscles during maximum clenching.

OBJECTIVES: Despite the broad use of occlusal splints in the treatment of temporomandibular disorders, the efficacy of splints is a source of controversy. In this study, the effectiveness of occlusal splints on the electromyographic activity of the masseter and temporal muscles in healthy individuals was investigated. METHOD AND MATERIALS: An occlusal splint was made for 25 healthy individuals. Surface electromyographic recordings were done during maximum clenching without the splint and immediately after application of the splint. The relative level of activity in the masseter and temporal muscles was quantified by means of activity index. Paired t test and Wilcoxon signed-rank tests were used for data analysis. RESULTS: The mean electromyographic activities of masseter and temporal muscles (in mV/s) were 0.7712 and 1.0488 without the splint and 0.8396 and 0.9276 immediately after application of the splint. There was no significant difference between the electromyographic activities of both muscles before and after insertion of the splints. The activity index increased after application of the occlusal splints. This increase was also insignificant. CONCLUSION: Immediate application of occlusal splints has no significant effect on the activity of masseter and temporal muscles. It could decrease the relative activity of the temporal to the masseter muscle (increasing the activity index).     

3D planning in mandibular fractures using CAD/CAM surgical splints — A prospective randomized controlled clinical trial

This randomized controlled trial assessed the role of CAD/CAM splints in achieving anatomic reduction of fractured fragments and ideal occlusion, in comparison with conventional splints.Patients diagnosed with displaced mandibular fracture and post-traumatic malocclusion were allocated to study and control groups by simple randomization. A standardized surgical approach was followed to expose the fractures. Reduction of fractures was carried out using CAD/CAM and conventional splints in the study and control groups, respectively. The parameters assessed were: occlusion, interfragmentary separation, fit of the splint, patient comfort, and surgeon comfort. Mann-Whitney U tests were used to compare the study and control groups. To compare the groups pre- and post-intervention Wilcoxon signed rank tests were used. Chi-square tests were applied for proportion comparisons. The sample consisted of 30 patients.The study group demonstrated superior clinical outcomes with regards to intraoperative reduction of fracture (p < 0.001; mean – 3.93, SD – 1.43), and to achieving intraoperative occlusion (p = 0.483) and postoperative occlusion (p = 0.224). Statistically significant improvements in both patient comfort (p < 0.001; mean – 0.20, SD – 0.41) and surgeon comfort (p < 0.001) were found in the study group. In conclusion, CAD/CAM splints improve precision in fracture reduction and restoration of occlusion through a simple fabrication process.     

A systematic review on the effects of occlusal splint therapy on muscle strength

ABSTRACT

Objective: The aim of this study was to conduct a systematic review on the effectiveness of occlusal splints for improving muscle strength. Occlusal splints are oral appliances that cause joint stabilization.

Methods: A mix of medical and sports science terms was used to perform the search on several databases (Web of Science, Science Direct, SPORT Discus, PubMed, and Springer).

Results: Twelve studies were reviewed, and their analysis indicates a trend pointing toward a limited interaction between the use of occlusal splints and improved muscle strength.

Discussion: The extent of occlusal splints’ impact on muscle strength is presently unknown. At this stage, there is no general agreement as to whether occlusal splints can be used as ergogenic aids. The number of studies on this specific topic and their different experimental designs precludes drawing more definite conclusions. Further research is warranted to elucidate possible changes resulting from occlusal splints during exercise.     

The effects of mouthguards on the athletic ability of professional golfers

Abstract – The purpose of this study was to determine the effect of stabilization splints and mouthguards on the athletic ability of professional golfers. For this study, eight professional golfers with a mean age of 20.5 were selected. These participants performed four trials of 10 driver swings and 10 putts with or without a stabilization splint (control group) or mouthguard. For the 4th trial, the splints were adjusted using a simple blind test so that the participants were unaware of the unilateral molar contact. The drive distance, club head speed, initial ball speed, and putting accuracy were compared and analyzed before and after the application of equal bilateral molar occlusion. When the bilateral molar occlusion was applied using a mouthguard or stabilization splint, the club head speed and driving distance in the presence of the oral appliances were significantly increased compared with those without the presence of either appliance (P < 0.05). Alternatively, the initial ball speed and putting accuracy in the presence of these appliances were increased compared with those without the presence of an appliance; however, this effect was not statistically significant. When the mouthguards or stabilization splints were adjusted to result in unilateral molar occlusion, the club head speed and driving distance in the presence of the appliances were significantly decreased compared with those that were obtained without these appliances (P < 0.05). The initial ball speed and the putting accuracy were not affected by the use of the appliances. No difference was observed in the effectiveness of the stabilization splint and mouthguard when bilateral molar occlusion was performed. The occlusion stability that results from stabilization splints and mouthguards is thought to increase the club head speed and driving distance in professional golf players.     

Anterior midline point stop device (AMPS) in the treatment of myogenous TMDs: comparison with the stabilization splint and control group

Two occlusal splints, the full-arch stabilization splint and the anterior midline point stop (AMPS) device, were evaluated for their efficiency in relieving myogenous temporomandibular disorders (TMD). One hundred and fourteen patients with myogenous TMD were distributed into 3 groups. The first group was treated with the AMPS device, the second with the stabilization splint, and the third group was the control group. Pain intensity was scored using the visual analogue scale before treatment and 1 month and 3 months after treatment. Statistical Package for the Social Sciences (SPSS, Chicago, Ill) and multiple comparisons tests were used to compare results before and after treatment and to compare the groups. The use of AMPS device in the first group resulted in a significant improvement after 1 month and 3 months (P < or = .001) and showed a 56.66% pain reduction. A significant improvement was also noticed in the second group (P = .001) with a 47.71% pain reduction. Although pain reduction percentage appeared more in the first group, this was not statistically significant. There was a highly significant difference between groups treated with both kinds of splints and the control group. It was concluded that both types of occlusal splints are beneficial to patients with myogenous TMD.     

Influence of occlusal stabilization splints and soft occlusal splints on the electromyographic pattern, in basal state and at the end of six weeks treatment in patients with bruxism

The aim of this study is to assess the electrical activity generated in temporal and masseter muscles during voluntary muscular contraction of patients with bruxism, as a result of the use of two types of occlusal splints (occlusal stabilization splint and soft occlusal splint) in which 2 groups of 8 patients were evaluated -12 women and four men aged 19 to 40 years, who used a single type of occlusal splint for 46 to 60 days. The splints were made from sheets of rigid acetate plus heat-cured acrylic (occlusal stabilization splint, control group) and sheets of flexible acetate (soft occlusal splint, experimental group). Two electromyographic tests (EMG) were performed on each patient; one before placing the splint and another at the end of the treatment. The statistical analysis used was computerized variance ANOVA analysis with F distribution (P < or = 0.025). In the control group, muscle electrical activity increased significantly in 5 patients and decreased slightly in 3. In the experimental group, there was considerable reduction of such activity in 6 patients and a slight increase in 2. There is a statistically significant difference (P < or = 0.025) between the muscle electrical activity generated in the control group and in the experimental group. The increase in muscle electrical activity in the control group may have been due to a neuromuscular recovery process; while the decrease in the experimental group might have been due to a negative or decremental process of muscular organization to prevent the recruitment of new motor units. Occlusal stabilization splints are therefore considered better than soft occlusal splints.     

D-Bite (Digital-Bite): tecnica di costruzione CAD/CAM

Objectives

To manufacture an occlusal splint based on CAD/CAM technology.

Materials and methods

Plaster casts made from oral impressions were scanned with CAD/CAM technology. The CAD/CAM device employed was a structured light-based scanner. CAD generates a 3D digital image that can be used to design the splint. During the CAM phase, the D-Bite (Digital Bite) was created from a block of polymethyl methacrylate (PMMA) with a thickness of about 20 mm.

Results

The production of a digitally designed D-Bite (Digital Bite). The D-Bite manufacturing technique is standardized thanks to computer-assisted procedures.

Conclusions

The D-Bite manufactured with CAD/CAM technology provided excellent biological and esthetic results, and the manufacturing technique was simple and rapid.     

A novel method of computer aided orthognathic surgery using individual CAD/CAM templates: a combination of osteotomy and repositioning guides

The maxilla is usually positioned during orthognathic surgery using surgical splints, which has many limitations. In this preliminary study we present a new computer-aided design and manufacture (CAD/CAM) template to guide the osteotomy and the repositioning, and illustrate its feasibility and validity. Six patients with dental maxillofacial deformities were studied. The design of the templates was based on three-dimensional surgical planning, including the Le Fort osteotomy and the repositioning of the maxilla, and were made using a three-dimensional printing technique. Two parts of the templates, respectively, guided the osteotomy and repositioned the maxilla during operation. The traditional occlusal splint was used to achieve the final occlusion with the mandible in the expected position. Postoperative measurements were made between maxillary hard tissue landmarks, relative to reference planes based on computed tomographic (CT) data. The results of the measurements were analysed and compared with the virtual plan. The preliminary results showed that we achieved clinically acceptable precision for the position of the maxilla (<1.0 mm). Preoperative preparation time was reduced to about 145 min. All patients were satisfied with the aesthetic results. Our CAD/CAM templates provide a reliable method for transfer of maxillary surgical planning, which may be a useful alternative to the intermediate splint technique. Our technique does not require traditional model surgery, scanning of dental casts, or recording of the CAD/CAM splint.     

两类夹板固定重度牙周病松动前牙的疗效分析

目的：采用多项主客观指标结合的方法,评价金属烤瓷冠桥、尼龙丝加强树脂夹板固定重度牙周病松动牙的各自临床特点,为夹板类型的选择提供重要参考。方法：松动Ⅱ~Ⅲ度的牙周病前牙,经牙周基础治疗后,制作完成金属烤瓷冠桥和尼龙丝加强树脂夹板各10例,评价其客观指标牙周检查指数、咬合力、X线片和主观满意度6个月的临床疗效。结果：6个月后两组夹板基牙的PD值均有明显下降,咬合力显著升高,X线片显示骨密度和高度有一定程度的增长,并且获得满意的主观接受度。结论：两类夹板是保存重度牙周炎松动前牙的可靠、有效的方式,但必须长期坚持牙周维护以稳固疗效。     

Digital occlusal splints

A new digital process for producing occlusal splints is described. The process mirrors conventional restorative CAD/CAM systems consisting of scanning, customized CAD design, and machining. The method provides precise and consistent digital control over articulation and design parameters, and is suitable for mounted and unmounted cases. With over 2,500 beta cases to date, an overall reduction in adjustment time has been generally reported.     

Comparison of the efficiency of two types of intraoral splints in the RED system for maxillary distraction osteogenesis

PurposeThis study was conducted to compare the ratio of maxillary advancement to the amount of activation achieved by distraction osteogenesis (DOG) using a rigid external distraction system with two different types of intraoral splints and to evaluate the applicability of a new type of splint.Materials and methodsThe mechanical deformation and the distraction efficiency of two types of intraoral splints, Type 1 and Type 2, were evaluated. The Type 1 was a conventionally used intraoral splint. Type 2 was a reinforced, custom-made splint composed of twin-labial arches made of 0.060-in. orthodontic wires. In this study, 11 cleft lip and palate patients were analyzed; 5 patients were treated using Type 1 splint and the other 6 using Type 2. Lateral cephalograms taken at 4 stages—the onset, the end of activation, immediately after the removal of distraction device, and 1 year after distraction—were superimposed and measured to estimate the advancement and relapse at point A.ResultsType 2 splint demonstrated significantly higher strength than Type 1 in a tensile test. Distraction efficiency for Type 1 and Type 2 was 31.6% and 51.0%, respectively, demonstrating significantly higher efficiency for Type 2. On the other hand, the amount of relapse during the 1-year follow-up period did not show significant difference between two groups.ConclusionThe distraction efficiency was affected by the types of intraoral splints used and maxillary distraction could be effectively performed using the reinforced intraoral splint without impairing the stability after DOG.     

Fabrication of Easily Reproducible Occlusal Splints

Occlusal splints have been used for many years and for many dental problems. The ability to easily fabricate occlusal splints which are accurate and require a minimum of chair-time is an important consideration.

This article describes a method of occlusal splint fabrication which will produce an occlusal splint that meets the above criteria and also allows for duplicate splints to be easily made. During the process of fabrication, a mold of the splint occlusal form is made which can be used at a later date to reproduce the original splint. This will reduce inconvenience for the patient and reduce the dentist's chair-time.     

Soft versus hard occlusal splint therapy in the management of temporomandibular disorders (TMDs)

Aim

To compare between soft and hard occlusal splint therapy for the management of myofacial pain dysfunction (MPD) or internal derangement (ID) of the temporomandibular joint (TMJ) with reciprocal clicking.

Patients and methods

This study included 50 patients (age range: 24–47 years) who had been diagnosed with MPD or ID of the TMJ in the form of reciprocal clicking. Patients were divided into two groups. They were treated for 4 months with either a vacuum-formed soft occlusal splint constructed from 2-mm-thick elastic rubber sheets (soft splint group) or a hard flat occlusal splint fabricated from transparent acrylic resin (hard splint group). Monthly follow-up visits were performed during the treatment period. Before treatment and 1, 2, 3 and 4 months after treatment, the dentist measured all parameters of TMJ function (pain visual analog scores, tenderness of masticatory muscles, clicking and tenderness of the TMJ, and range of mouth opening).

Results

All parameters of TMJ function showed significant improvement in both groups during the follow-up period, with a statistically significant difference between the two groups at the 4-month follow-up visit.

Conclusions

Both forms of occlusal splints (soft and hard) improved TMJ symptoms in patients with MPD or ID of the TMJ. However, the soft occlusal splints exhibited superior results after 4 months of use.     

Influence of periodontal ligament simulation and splints on strains developing at the cervical area of a tooth crown

Many in vitro tooth models do not incorporate periodontal ligament (PDL) simulation. This study presents the influence of physiologically loaded occlusal splints on cervical strains in a model incorporating roots and PDL. Four sets (N = 10) of occlusal splints differing in material (hard/soft) and location (upper/lower) were prepared for first maxillary and mandibular anatomic molars. Two strain gauges were bonded to the buccal and lingual aspects of the lower molar. Teeth were embedded in acrylic resin with/without a PDL‐simulating material. Force vs. strain data were acquired during loading and the maximal strains at 500 N were analyzed. When PDL was incorporated into the model without splints, buccal compressive strains were significantly decreased. Usage of a soft splint resulted in compressive strains on both tooth aspects. Usage of a hard splint on the lower tooth resulted in higher compressive strains on the lingual side compared with the buccal side, whereas usage of this splint on the upper tooth resulted in tensile strains on the lingual side. Bending towards the buccal side occurred when the splints were located on the upper tooth. Soft splints reduce buccal bending, but do not reduce cervical strains. Periodontal ligament stimulation materials should therefore be incorporated in models involving teeth.     

Influence of Different Centric Functions on Electromyographic Activity of Elevator Muscles

This study compares eight different occlusal centric functions with splint contact on different teeth in order to determine their influence on mandibular elevator electromyographic (EMG) activity.

Maxillary occlusal splints were built for eight subjects without craniomandibular dysfunction. Investigators divided each splint into three parts, in order to record different occlusal schemes in the same subject without varying the vertical dimension. EMG activity in the left masseter and anterior temporal muscles was registered during maximum voluntary clenching.

Results showed higher masseter activity with the splint than without, and anterior temporal activity was similar. There was a significant decrease of EMG activity with the anterior section of the splint. There were no significant differences between the remaining centric functions and clenching with the complete splint, except for the centric function with contralateral posterior contact, in which elevator activity was significantly reduced.

Results suggest that bilateral posterior occlusal stabilization is critical for maximum interocclusal force.     

The immediate effects of a stabilization splint on the muscular symmetry in the masseter and anterior temporal muscles of patients with a craniomandibular disorder

In 36 myogenous craniomandibular disorder patients, the immediate effects of a stabilization splint on the symmetry in the activities of the masseter and anterior temporal muscles during submaximal clenching at five clenching levels were investigated electromyographically. After the adjustment of the splint necessary at the time of delivery, 20 splints remained free from occlusal interferences throughout the treatment period and thus needed no further adjustment. These splints caused an immediate improvement in masseter muscle symmetry at the time of delivery (p less than 0.01). However, 16 splints needed further adjustment for occlusal interferences at the first recall, 2 weeks after delivery of the splint. These splints resulted in a small but statistically significant worsening in masseter muscle symmetry at the 10% clenching level (p less than 0.01). No such response was found for temporal muscle activity. The immediate changes in masseter muscle activity suggest that muscular symmetry is an objective basis in the evaluation of the treatment provided.     

Computerized analysis of occlusal contacts in bruxism patients treated with occlusal splint therapy

PURPOSE

Occlusal splints are commonly used to prevent tooth wear caused by bruxism. However, the effects of splints on occlusion are still unclear. Although it is rarely alluded in literature, splints can provoke severe occlusal alterations and other complications. This study was aimed to identify differences in the responses of individuals with bruxism and healthy individuals to a full-arch maxillary stabilization splint in terms of occlusal changes.

MATERIALS AND METHODS

Occlusal contacts in 20 (5 male, 15 female) bruxism patients and 20 (5 male, 15 female) controls with normal occlusion were evaluated before and after occlusal splint therapy. T-Scan III, a computerized occlusal analysis system, was used to simultaneously measure occlusion and disclusion times as well as left-right and anterior-posterior contact distributions before splint therapy and 3 months after therapy. Wilcoxon and Mann-Whitney U tests were used for statistical analyses (α=.05).

RESULTS

No differences were found in the posterior contact of bruxism patients before and after stabilization splint treatment. However, differences in posterior contact were observed between bruxists and normal individuals prior to treatment, and this difference disappeared following treatment.

CONCLUSION

The results of this study showed the use of a stabilization splint may not have an effect on occlusion. However, the area of posterior occlusal contact among bruxists was found to be greater than that of normal individuals. According to this study, the clinical use of splints may be harmless.