Canine Guidance Occlusion Research Articles

Short dental implants in the posterior maxilla: a review of the literature.

The purpose of this study was to perform a literature review of short implants in the posterior maxilla and to assess the influence of different factors on implant success rate. A comprehensive search was conducted to retrieve articles published from 2004 to 2015 using short dental implants with lengths less than 10 mm in the posterior maxilla with at least one year of follow-up. Twenty-four of 253 papers were selected, reviewed, and produced the following results. (1) The initial survival rate of short implants in the posterior maxilla was not related to implant width, surface, or design; however, the cumulative success rate of rough-surface short implants was higher than that of machined-surface implants especially in performance of edentulous dental implants of length <7 mm. (2) While bone augmentation can be used for rehabilitation of the atrophic posterior maxilla, short dental implants may be an alternative approach with fewer biological complications. (3) The increased crown-to-implant (C/I) ratio and occlusal table (OT) values in short dental implants with favorable occlusal loading do not seem to cause peri-implant bone loss. Higher C/I ratio does not produce any negative influence on implant success. (4) Some approaches that decrease the stress in posterior short implants use an implant designed to increase bone-implant contact surface area, providing the patient with a mutually protected or canine guidance occlusion and splinting implants together with no cantilever load. The survival rate of short implants in the posterior edentulous maxilla is high, and applying short implants under strict clinical protocols seems to be a safe and predictable technique.

Effect of different lateral occlusion schemes on peri-implant strain: A laboratory study.

PURPOSEThis study aims to investigate the effects of four different lateral occlusion schemes and different excursions on peri-implant strains of a maxillary canine implant.MATERIALS AND METHODSFour metal crowns with different occlusion schemes were attached to an implant in the maxillary canine region of a resin model. The included schemes were canine-guided (CG) occlusion, group function (GF) occlusion, long centric (LC) occlusion, and implant-protected (IP) occlusion. Each crown was loaded in three sites that correspond to maximal intercuspation (MI), 1 mm excursion, and 2 mm excursion. A load of 140 N was applied on each site and was repeated 10 times. The peri-implant strain was recorded by a rosette strain gauge that was attached on the resin model buccal to the implant. For each loading condition, the maximum shear strain value was calculated.RESULTSThe different schemes and excursive positions had impact on the peri-implant strains. At MI and 1 mm positions, the GF had the least strains, followed by IP, CG, and LC. At 2 mm, the least strains were associated with GF, followed by CG, LC, and IP. However, regardless of the occlusion scheme, as the excursion increases, a linear increase of peri-implant strains was detected.CONCLUSIONThe peri-implant strain is susceptible to occlusal factors. The eccentric location appears to be more influential on peri-implant strains than the occlusion scheme. Therefore, adopting an occlusion scheme that can reduce the occurrence of occlusal contacts laterally may be beneficial in reducing peri-implant strains.

A prospective cross-over study to evaluate the effect of two different occlusal concepts on the masseter muscle activity in implant-retained mandibular overdentures.

BackgroundThe purpose of this prospective cross-over study is to evaluate the effect of bilateral balanced occlusion and canine guidance occlusion on the masseter muscle activity using implant-retained mandibular overdentures.MethodsAfter evaluation of 12 completely edentulous patients using cone beam computed tomography (CBCT), mucoperiosteal flaps were reflected exposing the mandibular interforaminal region. Two implants were placed in the interforaminal region for each of the 12 patients. After a healing period of 3 months, acrylic maxillary complete dentures and mandibular overdentures were fabricated with bilateral balanced occlusion for 6 patients and canine guidance occlusion for the other 6 patients. 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. p < 0.05 was considered statistically significant.ResultsThe 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 canine guidance occlusion were higher than bilateral balanced occlusion but with no statistically significant difference except between the right masseter muscles during clenching (p = 0.042*).ConclusionsBoth bilateral balanced occlusion and canine guidance occlusion can be used successfully in implant-retained mandibular overdentures without affecting masseter muscle activity.

SIGNS AND SYMPTOMS OF TEMPOROMANDIBULAR DISORDERS AND THEIR

Objectives: This study was done with the objective of determining the distance of movement between the maxillary and mandibular midline (DMM) and its relationship with the signs and symptoms of temporomandibular disorders (TMD) in canine-guided occlusion and to compare the obtained values between the right and left sides. Materials and Methods: One hundred females showing canine-guided occlusion and Angle's class I canine and molar relation were chosen for the study. The maxillary midline’s corresponding line was marked on the mandible with a marker pen in the patient's mouth, both during maximum intercuspation and at the edges of maxillary and mandibular canine contact. DMM was considered as the distance between the two lines (measured using a digital caliper). The percentages of signs and symptoms were compared using the chi-square test to determine the differences among the groups for the rates of TMD symp- toms, bruxism, joint sounds and unilateral chewing. Results: The mean value of the DMM for all subjects was found to be 3.61 mm on the right side and 3.64 mm on the left side. The values were subjected to a paired t -test, and the P value was statistically insignificant (P>0.05). Reported TMJ(temporo mandibular joints) clicking at the start was the only significant predictor (P<0.01) for TMD symptoms (pain in jaw), and bruxism was a marginally significant predictor for pain in the jaw (P=0.055). Other predictors from the baseline examinations (unilateral chewing, missing teeth) were insignificant. Conclusion: It can be concluded from this study that these values of DMM cannot be used for predicting the manifestation of TMD. Keywords : Canine-guided occlusion, midline moving, tmj disorders

Lateral occlusion schemes in natural and minimally restored permanent dentition: a systematic review

Clinicians commonly encounter the dilemma of which lateral occlusion schemes is most suitable for a specific patient. The aim of this review is to evaluate the prevalence of the lateral occlusion schemes that exist naturally. An electronic search was completed through PubMed (MEDLINE), Google Scholar and Cochrane Library. The search was confined to peer-reviewed studies published in English, up to April 2013. The literature search was supplemented by manual searching through the bibliography lists of the selected studies. The initial search retrieved a total of 575 studies. After applying the selection criteria, only 12 studies were suitable for inclusion. The Critical Appraisal Skills Programme (CASP) tools were utilised to appraise the quality of the studies. The prevalence of canine-guided, group function and balanced occlusions was reported. Overall, there was a clear variability between the studies. The prevalence of the lateral occlusion schemes appears to be influenced by the following factors: (i) the magnitude of excursion, (ii) an individual's age and (iii) the static occlusal relationship. During complete excursion, the canine-guided occlusion tends to be more frequently observed. After partial excursion, the most prevalent lateral occlusion schemes was group function occlusion. With ageing, the prevalence of canine-guided occlusion tends to be reduced and the prevalence of group function occlusion is increased. Dentition that is closer to Class II occlusion exhibits mainly canine-guided occlusion, while for Class III occlusion, group function occlusion is more prevalent. The studies revealed no relationship between the lateral occlusion schemes and TMD development.

Occlusal designs on masticatory ability and patient satisfaction with complete denture: A systematic review

ObjectivesTo systematically review clinical outcomes of different occlusal designs of complete dentures. MethodsUsing a various key words, an electronic search of clinical trials published in English and Chinese literature was performed from four databases: Medline/PubMed, EMBASE, Cochrane Library, and CBM. Furthermore, a manual searching of the relevant journals and the bibliographies of reviews was performed. General satisfaction, masticatory ability, retention, and stability were major criteria for the evaluation of the outcomes. Studies met these criteria were selected for a full-text reading. The whole processes were performed by two reviewers independently. ResultsThis systematic review started with 1030 articles, which were finally narrowed down to seven, according to the inclusion criteria. The following occlusal designs were included and analyzed: anatomic occlusion, balanced occlusion, canine guidance occlusion, lingualized occlusion, monoplane occlusion, and bilateral-balanced and canine-guided design. Three of the seven studies showed that lingualized occlusion had ratings of higher patients’ satisfaction than other occlusion designs. On the other hand, the canine-guided occlusion dentures demonstrated equal or better clinical performances than bilateral-balanced dentures. Because of the heterogeneity and bias of the studies, it was not possible to analyze the data statistically. ConclusionsLingualized occlusion and canine-guided occlusion can be successfully applied in the fabrication of complete dentures. Canine guided occlusion has also been shown to be satisfactory. More well-controlled randomized trials are needed regarding canine-guided occlusion and the relationship between alveolar ridge resorption, different occlusal schemes and patient satisfaction. The conventional prosthodontic wisdom that complete dentures require a balanced occlusal design is not supported by the included literature. Clinical significanceA suitable occlusal scheme would be a critical factor for a successful complete denture. However, there is no conclusive evidence to support which occlusal design is more appropriate for fabricating a successful complete denture. In occlusal design of conventional complete denture, lingualized occlusion can provide better clinical outcomes than other occlusal designs; meanwhile, canine-guided occlusion also can be used in clinic practice.

An in vivo study to determine the range of posterior teeth disclusion on working side in canine-guided occlusion

This study was done with the objectives to determine the range of functional zone between the intercuspal positions and edge to edge position, the range of incomplete and complete disclusion of posterior teeth in canine-guided occlusion, and to have a gender comparison and comparison between right and left sides of the obtained values. Thirty-five subjects showing canine-guided occlusion and Angle's class I canine and molar relation were chosen for the study. Maxillary midline and a corresponding line on the mandible were marked in maximum intercuspation with marker pen in the patient's mouth. Lines from 1 to 5 mm were marked on maxillary central incisor with marker pen. A dental floss was looped around the distal surface of mandibular last molar and the subject was asked to make left lateral movement (working side) at 1-mm intervals. The point at which floss was freed posteriorly was considered as initial disclusion and the point at which edges of maxillary and mandibular canines contacted was considered as complete disclusion. Most of the male and female subjects in the study showed progressive disclusion on right side and delayed disclusion on left side. The range of complete disclusion was 3-4 mm in males and 2-3 mm in females irrespective of the side. The range of functional zone was 1-4 mm irrespective of side or gender. There is a need to redefine canine guidance in terms of immediate disclusion, delayed disclusion, and progressive disclusion.

Effect of non‐working occlusal contacts on vertical condyle position

The presence of non-working occlusal contacts is often considered harmful for the temporomandibular joint. Thus, the purpose of this study was to investigate the effect of non-working occlusal contacts on the condylar position during submaximal and maximal clenching. The study comprised 22 healthy subjects having a canine-guided occlusion. None of them had a third molar and none of them had a missing tooth or showed tooth mobility. All subjects clenched on (i) the canine, (ii) the canine while a stiff bite registration material was positioned between the second premolar and the first molar on the non-working side. The clenching level was controlled by surface electromyography of the masseter muscle. During clenching, the vertical and horizontal condylar position was predicted using six degrees of freedom ultrasonic motion analyser. Clenching on the canine caused a cranial movement of the non-working side condyle. This movement was reduced by 0.6-0.9 mm when the subjects clenched while the artificial non-working side contacts were in place. These results indicate that the contacts on the non-working side may be able to prevent upward joint movement.

Short Dental Implants in Posterior Partial Edentulism: A Multicenter Retrospective 6‐Year Case Series Study

Implants <10 mm long in the posterior regions of partial edentulous patients have a higher failure rate in many clinical reports. The purpose of this case series study was to evaluate implant survival when a biomechanical approach was used to decrease stress to the bone-implant interface. A retrospective evaluation of 273 consecutive posterior partially edentulous patients treated with 745 implants. 7 or 9 mm long, supporting 338 restorations over a 1- to 5-year period was reviewed from four private offices. Implant survival data were collected relative to stage I to stage II healing, stage II to prosthesis delivery, and prosthesis delivery to as long as 6 years follow-up. A biomechanical approach to decrease stress to the posterior implants included splinting implants together with no cantilever load, restoring the patient with a mutually protected or canine guidance occlusion, and selecting an implant designed to increase bone-implant contact surface area. Of the 745 implants inserted, there were six surgical failures from stage I to stage II healing to prosthesis delivery. No implants failed after the 338 final implant prostheses were delivered. A 98.9% survival rate was obtained from stage I surgery to prosthetic follow-up. Short-length implants may predictably be used to support fixed restorations in posterior partial edentulism. Methods to decrease biomechanical stress to the bone-implant interface appear appropriate for this treatment.

The relationship between static and dynamic occlusion in 14-17-year-old school children.

This study investigated the relationship between static and dynamic occlusion in school children. A total of 447 subjects, within an age range of 14-17 years with no history of orthodontic treatment or trauma to the teeth were included in this study. Static occlusion was determined for both incisal and molar relationship. Dynamic occlusion was determined in lateral and protrusive movements of the mandible. The majority of the subjects had class I static occlusion for both incisor and molar relationship (45 and 54%, respectively). Canine-guided occlusion was the dominant type of dynamic occlusion (57%) and most of the subjects had no posterior contact in protrusive movement (78%). There was an association between canine guidance with class II static occlusion. Statistically, a significant relationship was found between the dynamic and static occlusion of the incisor (P < 0.001) but not with the molar (P > 0.05).

Comparison of the electromyographic activity of individuals with canine guidance and group function occlusion

The purpose of this study was to investigate occlusal schemes (canine guidance and group function) in relation to masticatory muscle activity. It was performed on 30 subjects, 15 with canine guidance and 15 with group function. Bilateral electromyographic recordings of masseter and anterior temporal muscles were obtained by surface electrodes during gum chewing and sliding laterally from centric relation while the teeth were in contact. The obtained data for both groups were compared statistically. Electromyograms were also evaluated visually. There was no significant difference in results between the occlusal schemes. However, canine guidance showed a narrower chewing model than group function and reduced anterior temporal muscle activity during sliding. This suggests that in the presence of healthy and good supportive canine teeth, canine guidance occlusion will be preferable.