Canine Guidance Occlusion Research Articles

Long-term occlusal tooth wear at the onset of permanent dentition

ObjectivesThis study quantified the long-term occlusal wear in the natural posterior teeth and the associations per tooth type within the dentition.MethodsThe sample included 70 orthodontically treated subjects (52 females and 18 males; median age, 14.3 years), followed for a 12.7-year period. They were consecutively selected with no tooth wear–related criteria. Post-treatment (T1) and follow-up dental casts (T2) were scanned and superimposed through three-dimensional methods. Occlusal wear volume of posterior teeth and tooth wear patterns were investigated through non-parametric statistics and analysis of covariance.ResultsThere were no significant differences between contralateral teeth. The average occlusal wear per posterior tooth was 2.3 mm3, with 65.2% of teeth showing values greater than 1 mm3. Males, mandibular teeth, and first molars exhibited slightly greater wear levels than females (median, 2.57 and 2.21 mm3, respectively; p = 0.005), maxillary teeth, and first or second premolars, respectively. In all first premolars and in the mandibular second premolars, the buccal cusps were primarily affected with no other distinct patterns. There were weak to moderate correlations between tooth types, apart from certain strong correlations detected in males.ConclusionsPosterior tooth wear was highly prevalent after a 13-year period starting at the onset of permanent dentition. The detected patterns are in accordance with the concept of canine guidance occlusion that is transforming into group synergy through function.Clinical relevanceThe widespread tooth wear occurrence and the high intra- and inter-individual variability underline the need for individual patient monitoring to identify high-risk patients at early stages.

A Comparison of Occlusal Schemes with Condylar Inclination and Anterior Guidance in Dentate Individuals.

To compare occlusal schemes with condylar inclination and anterior guidance in dentate individuals. A total of 26 dentate patients of Indian origin between the ages of 18 and 30 with canine-guided occlusion and 26 patients with group function occlusion were included in the study. The School of Articulator Munich (SAM) Axioquick system was used to assess the condylar guidance and eccentric tracings of the patients. For analyses, Student t test was used. For quantitative data, the means and SDs were calculated. For statistical analyses, the probability of type-I error of .05 was considered statistically significant. The mean condylar guidance for canine-guided and group function occlusion was 38.4 ± 12.7 degrees and 30.5 ± 12.5 degrees on the right side, respectively. On the left side it was 36.5 ± 13.0 degrees and 27.5 ± 12.0 degrees for canine-guided and group function occlusion, respectively, with a statistically significant difference (P = .01). The condylar guidance, incisal guidance, Bennett angle, protrusion, left lateral and right lateral movement, and left and right lateral angles were analyzed statistically between the two types of occlusions. The results showed a statistically significant difference between the two groups for all parameters except right condylar guidance. Furthermore, all parameters were higher in the canine-guided occlusion group over group function occlusion. Within the study limitations, it was concluded that the condylar guidance was steeper in canine-guided occlusion than in group function occlusion. The eccentric parameters were steeper in canine-guided occlusion than in group function occlusion. This study showcases that the condylar guidance might not play a major role in determining the occlusal scheme but that the incisal guidance determines the occlusal scheme predominantly in Class 1 occlusion patients.

Survival rates, patient satisfaction, and prosthetic complications of implant fixed complete dental prostheses: a 12-month prospective study.

To determine the survival rate, incidence of prosthetic complications, and patient satisfaction of implant fixed complete dental prostheses (IFCDPs) after a mean observation period of 1.4 years. Twenty-eight (28) eligible participants were recruited according to specific inclusion and exclusion criteria. The definitive metal-acrylic resin IFCDPs consisted of titanium bars veneered with acrylic resin and acrylic denture teeth. Prosthodontic complications, divided into major and minor, were monitored. Parameters such as gender, jaw location, bruxism, and occlusal scheme were evaluated. Moreover, a questionnaire was administered throughout the study to assess patient satisfaction. Poisson regression as well as repeated measures ANOVA were used for statistical analysis. Fourteen (14) males and 14 females were enrolled and followed-up at 3, 6, and 12 months. All IFCDPs survived (100% survival rate). The most frequent minor complication was the loss of material used to close the screw access hole (20% out of total complications). The most frequent major complication was chipping of the acrylic denture teeth (77.14% out of total complications). Gender (p = 0.008) and bruxism (p = 0.030) were significant predictors for the total major complications (major wear and major chipping) while occlusal scheme was a significant predictor for major chipping events (p = 0.030). While IFCDPs demonstrated high prosthetic survival rates, they also exhibited a high number of chipping events of the acrylic veneering material, especially in males, bruxers, and individuals with canine guidance occlusion. However, the occurrence of these prosthetic complications did not negatively affect patient satisfaction.

Modified Cantilever System (MCS) for Early Distalization of Palatally Impacted Canine in an Adult—A Case Report

Maxillary canine impaction is a malocclusion feature of very low prevalence (0.9%-2.2%) with a preponderance to females over males in the ratio of 2:1. However, when it presents, it is a complex orthodontic challenge. Treatment choices vary from no treatment to surgical exposure followed by orthodontic traction. Surgical exposure and orthodontic traction is an option that requires careful consideration of factors such as labiolingual position of the crown, vertical position of the tooth relative to mucogingival junction, amount of attached gingiva, and mesiodistal position of the crown. Age is an important factor in the prognosis of impacted maxillary canine treatment. Prognosis is lower in an adult compared to a younger patient and worsens with age. We report this case of impacted left maxillary canine (23) with palatal displacement in a young adult. A modified cantilever system was used for an early movement of canine from the lateral incisor which showed a grade II mobility. This along with controlled mechanics resulted in bringing the impacted 23 into class I position in the arch, thereby achieving a stable canine-guided occlusion within a period of 16 months.

Comparison of Canine-Guided Occlusion with Other Occlusal Schemes in Removable Complete Dentures: A Systematic Review

Choosing an adequate occlusion is challenging during the construction of artificial dentures, and critical for patient satisfaction. However, there is no conclusive evidence to support which occlusal design is more appropriate. The aim of this systematic review was to evaluate canine-guided occlusion in comparison to other occlusal schemes in removable complete denture wearers. The review was conducted according to the Preferred Reported Items for Systematic Review and Meta-Analysis (PRISMA) guidelines. An extensive search was carried out on (PubMed (National Library of Medicine)), Scopus (Elsevier), Cochrane collaboration (Wiley), Science Direct (Elsevier) and Europe PMC (European Bioinformatics Institute). English and non-English studies were identified using keywords on canine-guided occlusion, denture occlusion, dental occlusion and artificial occlusal schemes. Out of 1759 articles searched, 18 were selected based on the inclusion criteria. The included studies were interpreted for the descriptive analysis for the calculation of occlusal schemes, occlusion assessment parameters, the outcome of the occlusal schemes and types of removable prosthesis used. The systematic analysis of occlusal schemes revealed that canine-guided occlusion is viable compared with other occlusal designs in terms of patient satisfaction, mastication, retention, esthetics, phonetics, oral-health-related quality of life and muscle activity. The type of occlusal scheme influences the complete denture patient’s’ masticatory efficiency, satisfaction, retention, phonetics and esthetics. Nevertheless, physical, physiological, mechanical and psychological factors play a vital role in the success of removable complete dentures. The canine-guided occlusal scheme is preferred because of its simplicity, less time consumption, good masticatory performance, ease of fabrication and modification into bilateral balanced occlusion if required. Further studies are required to reduce the controversies related to jaw relations, gnathology and occlusal schemes in complete dentures.

Biomechanical Behavior of All-on-4 and M-4 Configurations in an Atrophic Maxilla: A 3D Finite Element Method.

BackgroundIn edentulous patients, the concept of 4 implants with early loading has been widely used in clinical settings. In the case of bone atrophy in the anterior maxilla, using short implants or an angulated implant may be a good choice for treatment. The occlusal scheme remains a key aspect of All-on-4. The aim of this study was to use the 3-dimensional (3D) finite element method (FEM) to evaluate how different All-on-4 designs for canine-guided and group function occlusion affected the distribution of stress in the atrophic premaxilla.Material/MethodsA 3D edentulous maxilla model was created and in 3D FEM, 3 different configurations – M4, All-on-4, and short implant – were modeled by changing the anterior implants and using 2 different occlusal schemes. For each model, the occlusal load was applied to simulate lateral movements. For cortical bone, the maximum and minimum principal stress values were generated, and for ductile materials, von Mises stress values were obtained.ResultsNo significant differences were detected among the models; generally, however, the highest stress values were observed in the M-4 model and the models with short implants. Slightly higher stress values were observed in the group function occlusion group than in the canine-guided occlusion group.ConclusionsTo promote better primary stabilization, M-4 or short implant configurations with canine-guided occlusion appear to be preferable for patients who have severe atrophy in the anterior maxilla.

An evaluation of the stress effect of different occlusion concepts on hybrid abutment and implant supported monolithic zirconia fixed prosthesis: A finite element analysis

PURPOSEThe aim of this study is to evaluate the effects of canine guidance occlusion and group function occlusion on the degree of stress to the bone, implants, abutments, and crowns using finite element analysis (FEA).MATERIALS AND METHODSThis study included the implant-prosthesis system of a three-unit bridge made of monolithic zirconia and hybrid abutments. Three-dimensional (3D) models of a bone-level implant system and a titanium base abutment were created using the original implant components. Two titanium implants, measuring 4 × 11 mm each, were selected. The loads were applied in two oblique directions of 15° and 30° under two occlusal movement conditions. In the canine guidance condition, loads (100 N) were applied to the canine crown only. In the group function condition, loads were applied to all three teeth. In this loading, a force of 100 N was applied to the canine, and 200-N forces were applied to each premolar. The stress distribution among all the components of the implant-bridge system was assessed using ANSYS SpaceClaim 2020 R2 software and finite element analysis.RESULTSMaximum stress was found in the group function occlusion. The maximum stress increased with an increase in the angle of occlusal force.CONCLUSIONThe canine guidance occlusion with monolithic zirconia crown materials is promising for implant-supported prostheses in the canine and premolar areas.

Effects of Occlusal Scheme on All-on-Four Abutments, Screws, and Prostheses: A Three-Dimensional Finite Element Study.

An ideal occlusal scheme plays an important role in a good prognosis of All-on-Four applications, as it does for other implant therapies, because of the potential impact of occlusal loads on implant prosthetic components. The aim of the present 3D finite element analysis (FEA) study was to investigate the stresses on abutments, screws, and prostheses that are generated by occlusal loads via different occlusal schemes in the All-on-Four concept. 3D models of the maxilla, mandible, implants, implant substructures, and prostheses were designed according to the All-on-Four concept. Forces were applied from the occlusal contact points formed in maximum intercuspation and eccentric movements in canine guidance occlusion (CGO), group function occlusion (GFO), and lingualized occlusion (LO). The von Mises stress values for abutment and screws and deformation values for prostheses were obtained, and results were evaluated comparatively. It was observed that the stresses on screws and abutments were more evenly distributed in GFO. Maximum deformation values for prosthesis were observed in the CFO model for lateral movement both in the maxilla and mandible. Within the limits of the present study, GFO may be suggested to reduce stresses on screws, abutments, and prostheses in the All-on-Four concept.

The Effect of Different Occlusal Concepts on Masticatory efficiency in Implant Supported Mandibular Over-dentures

The purpose of this study was to evaluate the effect of different occlusal concepts which are bilateral balanced occlusion, canine guided occlusion on masticatory efficiency, in implant supported mandibular over denture wearers.Material and methods: ten completely edentulous patients were selected for this study, aged 50 to 60 years old. All patients free from any systematic dieses. The patients were divided into three groups according to the treatment protocol; {GI} All patients wore denture with intra oral adjustment, {GII} five patients wore denture with bilateral balanced occlusion and {GIII} five patients wore denture with canine guided occlusion. All patients were submitted to masticatory efficiency test, after one month by using different textures of foods. The recordings data were analyzed using ANOVA. This was followed by Tukey’s post hoc test using LSD test. P< 0.05 was considered statistically significant. Results: with soft food, there was non-significant difference between the three groups, while with hard food; the greatest mean was recorded in occlusion after oral adjustment, whereas the lowest mean was recorded in bilateral balanced occlusion. Conclusion both bilateral balanced occlusion and canine guidance occlusion can be used successfully in implant supported overdentures without affecting masticatory function.

Biomechanical stress in removable complete dental prostheses: A narrative review of finite element studies

Aim: This review aimed to investigate the stress that arises in the conventional and implant-assisted removable complete dental prostheses (RCDPs) and supporting structures. Materials and Methods: A literature survey was conducted for the full-text English articles which only used finite element analysis to examine the stress developed in the conventional and implant-assisted RCDPs from January 2000 to May 2020. Results: In total, 1789 articles were included in the survey. Of the 1789 articles obtained, 1746 were excluded based on initial screening of the title and abstract. Finally, 24 articles were recruited for this study after excluding the duplicated articles with the same results. The significant findings and conclusions were extracted and grouped under biomechanical stress developed in complete dental prostheses, how to manage the stress developed in conventional RCDPs, and the factors affecting the development of stress in implant-assisted RCDPs. Conclusion: The RCDPs subject to different kinds of stress in the form of compressive and tensile strengths. The buccal flanges exhibit compressive strains responding to the vertical forces while labial flanges show the same type of strain responding to all force directions. The highest tensile strain concentration exists at the anterior frenum, midline, and buccal flanges when the forces were horizontal. Whilst, retention and support in implant-assisted prostheses are exceptionally improved, the implants and prostheses are subjected to stress which may result in failure of these kinds of prosthesis. This stress can be managed by increasing the number and size and by decreasing the angulation of the implants, using splinted or short collar unsplinted abutments, reinforcing the denture base, and using canine guidance occlusion.

Masticatory function in complete denture wearers varying degree of mandibular bone resorption and occlusion concept: canine-guided occlusion versus bilateral balanced occlusion in a cross-over trial

PurposeThe present cross-over study evaluated the masticatory function and maximum occlusal force of edentulous patients with complete dentures with bilateral balanced occlusion (BBO) and canine guidance (CG), with normal (NR) and resorbed mandibular ridges (RR). MethodsParticipants received new complete dentures and both occlusal concepts (BBO and CG) were applied for a period of 30 days each. The masticatory performance was evaluated with the sieving method; masticatory ability with a visual analog scale (VAS) and maximum occlusal force was assessed by means of a gnatodynamometer. Data were analyzed using repeated-measure ANOVA or Generalized Estimating Equations (GEEs), α = 0.05. ResultsThirty women completed the trial. The height of mandibular ridge was significant for the masticatory performance (ANOVA, p < 0.001, NR = 46.35 ± 12.18%, RR = 30.39 ± 9.94%), regardless of the occlusion guidance. A significant effect of the occlusion guidance was observed for the maximum occlusal force (ANOVA, p = 0.021, CG = 31.99 ± 12.74 N, BBO = 28.37 ± 9.83 N). The occlusion guidance was not significant for the masticatory performance (ANOVA, p = 0.156) and the height of the mandibular ridge did not influence on the occlusal force (ANOVA, p = 0.060). The interaction of the factors (guidance × ridge) was not significant for masticatory performance (ANOVA, p = 0.184) and occlusal force (ANOVA, p = 0.236). The VAS scores showed a significant effect of the ridge on chewing of lettuce, resulting in greater ease (GEEs, p = 0.016) and chewing quality (GEE, p = 0.028) of this food for participants with resorbed ridges. Participants with CG reported greater ease of chewing fresh bread and beef, and expressed higher quality of chew raw carrot. Participants with CG and normal ridges exhibited the highest overall chewing ability, in comparison to BBO (Bonferroni, p < 0.05, CG = 91.9, BBO = 72.7). ConclusionsCG represents a viable alternative to the BBO in complete dentures with satisfactory clinical results related to the self-perception of chewing and occlusal force.

Prospective clinical study of bilateral balanced occlusion (BBO) versus canine-guided occlusion (CGO) in complete denture wearers.

Previous studies have often discussed occlusal concepts for complete dentures without formulating a recommendation. Various options are available, the most common ones being canine-guided occlusion (CGO) and bilateral balanced occlusion (BBO). We designed a prospective randomized study to compare these two schemes with the goal of formulating a recommendation. Forty patients could be evaluated. In a crossover design, they were randomized to a CGO>BBO group and a BBO>CGO group, each starting out by wearing their dentures with the first occlusal scheme for 3months, followed by a first investigator- and patient-centered assessment. Then, each patient was transitioned to the other occlusal scheme by replacing the denture setup in the dental laboratory, followed by another 3months of intraoral use and a second assessment. Wilcoxon-Mann-Whitney and marginal homogeneity tests were used for statistical analysis. All statistically significant differences favored the CGO concept. Based on patient ratings, the CGO>BBO group preferred its esthetics (p= 0.02) and the BBO>CGO group its mandibular retention (p= 0.05), phonetics (p= 0.03), and masticatory function (p= 0.01). Based on investigator assessments, maxillary denture retention was found to significantly improve among the BBO>CGO patients after transition to CGO (p= 0.01). Within the limitations of this study, canine guidance can be recommended as a comfortable alternative to bilateral balanced occlusion for complete dentures. This recommendation can reduce the time requirements for the fabrication of complete dentures in dental laboratories.

Finite Element Stress Analysis of Applied Forces to Implants and Supporting Tissues Using the "All-on-Four" Concept with Different Occlusal Schemes.

The aim of this study was to evaluate stress distributions on implants and alveolar bone due to occlusal load produced during chewing by prostheses prepared according to the All-on-Four concept with different occlusal schemes using a finite element analysis method. On standard jaw models, teeth were set in accordance with the basic standards of canine-guided occlusion, group function occlusion, bilateral balanced occlusion (BBO), lingualized occlusion, and monoplane occlusion schemes. Three-dimensional (3D) images of these models were obtained using a surface scanner. Implants, superstructures, the maxilla, and mandible were modeled in the All-on-Four concept with 3D modeling software. Forces were defined on contacts formed in maximum intercuspation, lateral, and protrusive movement position for all 5 occlusion types. Stress outputs were recorded as maximum and minimum principal stresses (Pmax , Pmin ) and von Mises stress values for the implants. The highest Pmax value for the maxilla was observed in cortical bone in the group function occlusion during lateral movement (15.56 MPa). For the mandible, the highest Pmax value was observed on the cortical bone in maximum intercuspation of lingualized occlusion (72.75 MPa). The highest Pmin value for the maxilla was observed during the lateral movement in group function and for the mandible in BBO (-29.23 and -86.31 MPa, respectively). The lowest stress values were observed with canine-guided occlusion in all related conditions and on all structures. With the limitations of this simulation study, considering stresses on alveolar bone and implants in All-on-Four applications, the use of canine-guided occlusion may be suggested.

ELECCTROMYOGRAPHIC EVALUATION OF CANINE GUIDANCE OCCLUSION AND BILATERAL BALANCED OCCLUSION IN THERMOPLASTIC COMPLETE DENTURES

The purpose of this study was to evaluate the effect of two occlusal schemes; canine guidance occlusion and bilateral balanced occlusion on the masseter and temporalis muscle activity in thermoplastic complete dentures. Ten male completely edentulous patients whose ages ranged from 55 to 70 years were selected. Half of the selected patients received a thermoplastic complete denture with canine guidance occlusal scheme and the other half of the patients received a thermoplastic complete denture with bilateral balanced occlusal scheme. Electromyographic evaluation of the masseter and temporalis muscles, during chewing banana, peanut and carrot, was conducted on the patients after using their dentures for one month. Each occlusal scheme was then converted into the other scheme using the same dentures, and the procedure of evaluation was repeated after another one month. The data were collected, tabulated and analyzed by using Paired sample t-test. The results of this study showed that there was no significant difference between the canine guidance occlusal scheme and the bilateral balanced occlusal scheme in the electromyographic activity of both masseter and temporalis muscles during chewing all test foods. It was concluded that both bilateral balanced occlusion and canine guidance occlusion can be used successfully in thermoplastic complete dentures without affecting the masseter or temporalis muscle activity.

Occlusion design of edentulous implant prosthesis

The occlusion design of dental implants is related to the growing popularity of dental implantology. This paper discusses the occlusion design of the edentulous implant prosthesis and the relationships between stress change and the alveolar bone and between the occlusal design and implantation complications. The horizontal relationship of condyle, the design of the canine-guided occlusion, and the similarities and differences between the dental implant and the natural teeth on biteforce response are mentioned.

MASTICATORY EFFICIENCY OF CANINE GUIDANCE OCCLUSION AND BILATERAL BALANCED OCCLUSION IN THERMOPLASTIC COMPLETE DENTURES

ABSTRACT The purpose of this study was to evaluate the masticatory efficiency of two occlusal schemes; canine guidance occlusion and bilateral balanced occlusion in thermoplastic complete dentures. Ten male completely edentulous patients whose ages ranged from 55 to 70 years were selected. The selected patients were free from any temporomandibular joint disease in order not to affect their masticatory efficiency. Half of the selected patients received a complete denture with canine guidance occlusal scheme and the other half of the patients received a complete denture with bilateral balanced occlusal scheme. One month was left as an adaptation period then the masticatory efficiency of the first occlusal scheme was tested, then the occlusal scheme was changed to the other one. After another one month, the masticatory efficiency of the second occlusal scheme was tested. The data were collected, tabulated and analyzed by using Paired-sample t-test. The results of this study showed that there was no significant difference between the canine guidance occlusal scheme and the bilateral balanced occlusal scheme in the number of strokes, the number of swallows and the time (in seconds) elapsed during chewing all test foods (banana, peanut and carrot). It was concluded that both bilateral balanced occlusion and canine guidance occlusion can be used successfully in thermoplastic complete dentures without affecting the masticatory efficiency. Keywords: Masticatory efficiency, canine guidance occlusion, bilateral balanced occlusion, thermoplastic complete dentures.

Electromyographic activity changes of jaw-closing muscles in patients with different occlusion schemes after fixed prosthetic restoration

Background/Aim: To investigate the electromyographic (EMG) activity changes of jaw-closing muscles in patients with different occlusion schemes and posterior edentulous span, after the placement of teethsupported fixed partial denture (FPD). Material and Methods: The study sample consisted of 20 patients (10 men and 10 women, the mean age being 50 years) with a posterior edentulous area that includes two missing premolars or one premolar and one molar. The participants were divided into two groups with different occlusion schemes: canine-guided occlusion (CGO) and group function occlusion (GFO). The metal-ceramic FPD were fabricated according to the clinic-standardized protocol. EMG activities of masseter and anterior temporalis patients' muscles were recorded with bipolar surface electrodes during maximal voluntary clenching. EMG evaluation was repeated twice: (T1) before the fabrication of FPD (T2) after eight weeks of FPD cementation and intraoral functioning of restoration. The data were subjected to Analysis of Variance-ANOVA within the methodological framework of the General Linear Models with Repeated Measures. The Bonferroni test was used to compare multiple mean measures. Statistical analysis was conducted with SPSS ver. 11.5. The level of significance was predefined at a=0.05. Results: Group 1 with CGO presented significantly higher levels of masseter (mean maximum EMG average before 79.36μV and 139.68μV after) and temporalis (mean maximum EMG average before 79.07μV and 149.37μV after) EMG activity after FPD placement. Group 2 with GFO also showed significantly higher levels of masseter (mean maximum EMG average before 61.57μV and 165.30μV after) and temporalis (mean maximum EMG average before 56.94μV and 133.08μV after) EMG activity after the prosthetic restoration. Conclusions: It may be concluded that fixed prosthetic restoration, in both patients with canine-guided and group function occlusion, results in increased EMG jaw-muscle activity.

Complete Denture Occlusion

Proponents of bilaterally balanced occlusion believe that this occlusal concept is important for denture retention and stability. However, the critical appraisal of the literature reveals no scientific evidence to support the bilaterally balanced occlusion as the ideal occlusal concept for conventional complete dentures. Current evidence suggests that the occlusal concept has little influence on clinical outcomes or patient satisfaction. Additional randomized controlled clinical trials should be developed taking into account the influence of mucosal resiliency, alveolar ridge anatomy, and parafunctional activities on occlusal concept choice. In this paper, various types of complete denture occlusion (bilaterally balanced occlusion, lingualized occlusion, canine-guided occlusion) will be reviewed and compared.

The effect of two different occlusal concepts on the masseter muscle activity in implant retained mandibular overdentures

Aims: The purpose of this study was to evaluate the effect of bilateral balanced occlusion (BBO) and canine guidance occlusion (CGO) on the masseter muscle activity using implant-retained mandibular overdentures. Subjects and Methods: Cone beam computed tomography evaluation of twelve edentulous patients was completed. Mucoperiosteal flaps were reflected and two implants were placed in the interforaminal region for each of the twelve patients. After a healing period of 3 months, acrylic resin maxillary complete dentures and mandibular overdentures were fabricated with BBO for six patients and CGO for the other six patients. Positioner attachments were used. Electromyographic evaluation of the masseter muscles, during clenching on a silicon index and chewing peanuts and cake, was conducted on the patients after using their dentures for 4 weeks. Each occlusion concept was then converted into the other concept using the same dentures and the procedure of evaluation was repeated after 4 weeks. The recordings were analyzed statistically using Wilcoxon signed ranks test. The value of P Statistical Analysis Used: Kruskal–Wallis test and Mann–Whitney U-test were applied. Significance of the obtained results was judged at the 5% level. A P Results: The highest electromyographic activity of the masseter muscles was recorded during clenching on a preformed silicon index followed by chewing peanut then cake for both occlusal concepts. The recordings of the masseter muscle associated with CGO were higher than BBO but with no statistically significant difference. Conclusions: The results show that by applying CGO, muscle activities similar to bilaterally balanced occlusion were obtained.

Comparing the Electromyographic Features of the Masseter and Temporal Muscles in Patients with full Mouth Implant-supported FDPs and Natural Dentition

Background:Due to increasing demands for a full mouth implant reconstructions and the fact that the most failures are associated with biomechanical complications, determining the effect of different occlusal patterns on these complications seems inevitable. The aim of this study is to compare affection of different occlusal designs in full mouth implant reconstructed patients on electromyographic activity of temporal and masseter muscles compared to natural dentition.Methods:Thirty-two patients were included in this study, considering that 16 patients had natural dentition and the other 16 were full mouth implant reconstruction patients. In both groups, the participants were divided into two subgroups: 8 patients had canine guidance occlusal pattern and the other eight had a group function occlusal pattern. Muscle contractions were studied during both maximum intercuspation and lateral excursions to the point of intercanine contact using an electromyography device.Results:The average percentages of masseter muscle contraction in lateral excursions relative to maximum intercuspation were as follows: 72.20% in full mouth implant reconstruction patients with group function occlusion 69.49% in natural dentition with group function occlusion 58.85% in full mouth implant reconstruction patients with canine guidance occlusion 30.91% in natural dentition with canine guidance occlusion. The average percentages of temporal muscle contraction in lateral excursions relative to maximum intercuspation were as follows: 70.87% in full mouth implant reconstruction patients with group function occlusion 78.57% in natural dentition with group function occlusion 51.99% in full mouth implant reconstruction patients with canine guidance occlusion 31.55% in natural dentition with canine guidance occlusion.Conclusion:A canine guidance occlusal pattern in both, natural dentition and full mouth implant-supported FDP, patients resulted in decreased muscle contraction. This decreasing is more significant in natural dentition and it is better to establish a canine guided occlusion in a full mouth reconstruction patient.