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European Journal of Dentistry Jul 2023This study aimed to evaluate the effectiveness of conventional occlusal analysis in contrast with digital occlusal analysis in natural dentition. Occlusal analysis...
This study aimed to evaluate the effectiveness of conventional occlusal analysis in contrast with digital occlusal analysis in natural dentition. Occlusal analysis allows the identification of normal and abnormal occlusal contact points that alter the craniomandibular cervical system. We searched for articles with keywords [[dental occlusion]], [[natural dentition]], [[occlusal adjustment]], [[Immediate Complete Anterior Guidance Development]] [[mastication]], [[bite force]], [[premature contact]], [[occlusal balance]] [[articulating paper]]], [[spray]], [[Occlusal contacts]], and [[bite strength]]. They were considered observational , odds ratio and case control studies. We found 189 items. After evaluating the abstracts and full texts of the articles, 10 papers met the inclusion criteria. It was found that occlusal analysis allows the identification of the relationship between poor occlusion and the sensitivity of the teeth due to occlusal trauma, which is also related to temporomandibular joint pain in dynamic occlusion. The contacts of greater strength were observed in nonfunctional cusps, 48%, without ruling out the functional cusps, 24%. Despite being the universal method of occlusal control to date, the use of joint paper, remains subjective compared to the digital occlusal control device. Posture is considered directly related to occlusal trauma and temporomandibular disorders; without proper occlusal analysis, a clear diagnosis of the patient's joint condition cannot be obtained. Digital occlusal analysis is more objective than traditional occlusal analysis.
PubMed: 36252609
DOI: 10.1055/s-0042-1755626 -
Frontiers in Bioengineering and... 2021In dental research, bite force has become an important curative effect evaluation index for tooth restoration, periodontal treatment, and orthodontic treatment. Bite... (Review)
Review
In dental research, bite force has become an important curative effect evaluation index for tooth restoration, periodontal treatment, and orthodontic treatment. Bite force is an important parameter to evaluate the efficacy of the masticatory system. Physicians obtain the therapeutic basis for occlusal adjustment by measuring the bite force and the dynamic changes in occlusal contact at different stages of treatment and objectively evaluate the therapeutic effect. At present, many devices are used to record the bite force. Most of these devices use force transducers to detect bite force, such as strain gauge transducers, piezoresistive transducers, piezoelectric transducers, optical fiber transducers, and pressure-sensitive films. This article summarizes the various equipment used to record bite force, related materials and the characteristics of this equipment. It provides a reference for physicians to make choices during the clinical process and at the same time provides a basis for the development of new occlusal force measurement materials.
PubMed: 33898409
DOI: 10.3389/fbioe.2021.665081 -
Frontiers in Endocrinology 2022Occlusal support was proved to be associated with type 2 diabetes. Our aim was to investigate the association between the Eichner index and the prevalence of type 2...
Occlusal support was proved to be associated with type 2 diabetes. Our aim was to investigate the association between the Eichner index and the prevalence of type 2 diabetes. We included 715 participants with oral health examinations in the Shanghai Aging Study. The occlusal support status was determined by the number of functional occlusal support areas and Eichner index classifications. Those with fasting plasma glucose ≥126 mg/dL and/or hemoglobin A1c ≥6.5% and/or current medications for type 2 diabetes with relevant medical history were diagnosed with type 2 diabetes. Multiple logistic regression models were used to analyze the relationship between occlusal support status and type 2 diabetes. The average age of 715 participants was 73.74 ± 6.49 years old. There were 84 diabetics with 1.71 occlusal supporting areas on average. Seven hundred and fifteen participants were divided into 3 groups according to Eichner classifications: Eichner group A with 4 occlusal functional areas, Eichner group B with 1-3 occlusal functional areas or 0 area with anterior occlusal contact, and Eichner group C with no functional occlusal contact. Blood glucose level was significantly lower in participants of Eichner group A compared to those in group B or C. The ordinal logistic regression showed more occlusal supporting areas were significantly associated with less type 2 diabetes cases with an Odds Ratio(OR) of 0.253(95%CI 0.108-0.594) after adjusting covariates. Participants in Eichner group A had a significantly much lower OR of 0.078 for type 2 diabetes (95%CI 0.009-0.694) compared to those in Eichner group C after adjustment. The number of functional occlusal support areas might be inversely related to the blood glucose level and the prevalence of type 2 diabetes.
Topics: Aged; Aged, 80 and over; Aging; Blood Glucose; China; Diabetes Mellitus, Type 2; Humans
PubMed: 36004339
DOI: 10.3389/fendo.2022.934274 -
Journal of Advanced Pharmaceutical... Nov 2022Occlusal analysis is important to analyze any disharmony in occlusion. Atraumatic dental occlusion leads to evolution of T-scan. T-scan gives a valuable procedure for...
Occlusal analysis is important to analyze any disharmony in occlusion. Atraumatic dental occlusion leads to evolution of T-scan. T-scan gives a valuable procedure for clinical assessment and perception of occlusal problems. T-scan can also be used in periodontitis patients for checking the occlusal pattern. Occlusal problems and periodontal disease relationship remains controversial. Further research is needed to determine whether occlusal adjustment is necessary for periodontal treatment. The main aim of the study was to assess the occlusal pattern using T-scan in periodontitis patients. Thirty periodontitis subjects were taken and checked for occlusion using T-scan. The subject's age group was 35-55 years. The study included 15 males and 15 females. Plaque index, gingival index, attachment loss, probing depth, centric occlusion (CO), protrusion, right lateral, and left lateral were the parameters studied. Occlusal adjustments were needed to decrease and dissipate the abnormal occlusal forces. The significance of statistical tests for various movements are as follows: CO (right and left) ( = 0.077) > 0.05; protrusion (right and left) ( = 0.09) > 0.05; left side lateral (right side and left side) ( = 0.01) < 0.05; right lateral (right side and left side) ( = 0.00) < 0.05. CO and protrusion (right, left) for males and females are not significant. Left lateral and right lateral (right, left) for males and females were significant. The T-scan manages adequate specificity and sensitivity. Hence, these act as a distinctive tool for diagnosis and better unreliable when used intraorally. The T-scan method is definitely a valuable tool for examining and evaluating the occlusal contacts during maximal intercuspation.
PubMed: 36643123
DOI: 10.4103/japtr.japtr_225_22 -
Journal of Clinical Medicine Jan 2023The inaccurate maxillomandibular relationship of virtual casts following alignment by the vestibular scan may result in intersection (intermesh penetration) between...
BACKGROUND
The inaccurate maxillomandibular relationship of virtual casts following alignment by the vestibular scan may result in intersection (intermesh penetration) between opposing dental arch surfaces. Intersection occurs at short interocclusal distances in the occlusal contact area (OCA) and may result in infra-occluded definitive restorations. The purpose of this clinical study was to compare initial (by the proprietary scanner software) and new alignments (by a standalone 3D software) of virtual casts regarding OCA and intersection failure. New alignments aimed to rectify intersections by refinement of occlusal contacts.
MATERIAL AND METHODS
The virtual casts of 30 patients following digital and conventional impression-taking were analyzed, which were acquired for single implant restoration in the posterior site. Digital impressions were performed by both IOS 1 (3M True Definition) and IOS 2 (TRIOS 3), either as complete- or partial-arch scans, respectively. Mounted gypsum casts were digitized as complete-arch by a laboratory scanner (LS) in enabled and disabled mode to avoid intersection [LS (+)/LS (-)]. All virtual casts were newly aligned by a 3D software. The difference of the OCA and the area of intersection were calculated for initial and new alignments, using interocclusal distance ranges of 0-100 μm, 0-10 μm or <0 μm (=intersection). The difference of the OCA was compared using a linear mixed model. The distribution of occlusal contact points per modality and alignment was assessed independently by three observers and estimated by inter- and intraclass correlation (ICC) coefficients.
RESULTS
Virtual casts following initial alignment demonstrated intersections irrespective of the modality. The mean area of the intersection was most for IOS 2 (79.23 mm), followed by IOS 1 (48.28 mm), LS (-) (2.77 mm), and LS (+) (2.01 mm) in partial-arch scans. Complete-arch scans demonstrated an area of intersection of 70.63 mm for IOS 1 followed by 65.52 mm (IOS 2), 6.13 mm [LS (-)] and 2.76 mm [LS (+)]. Newly aligned scans showed no intersections. The overall distribution of occlusal contact points demonstrated moderate reliability (ICC 0.63). Good reliability could be observed (ICC 0.9) for LS (-) scans.
CONCLUSIONS
Intersections in the area of occlusal contact points are a phenomenon restricted to virtual casts, which should be considered in CAD/CAM. Initial alignments of LS are less affected by this virtual phenomenon, and contact points may be more distinct according to their anatomic region compared to IOS. Furthermore, intersections can be rectified in a 3D software by adjustment of the maxillomandibular relationship.
PubMed: 36769645
DOI: 10.3390/jcm12030996 -
Clinical Oral Investigations Jul 2021To evaluate the precision of aligner (Invisalign®) treatment with the current material (SmartTrack®) in achieving expansion or contraction of the maxilla and occlusal...
OBJECTIVES
To evaluate the precision of aligner (Invisalign®) treatment with the current material (SmartTrack®) in achieving expansion or contraction of the maxilla and occlusal contacts as simulated in the proprietary planning software (ClinCheck®, CC).
MATERIALS AND METHODS
Thirty patients thus treated were retrospectively evaluated. Four maxillary models were analyzed per patient: a pretreatment model, a scan-based CC model, a posttreatment clinical model, and a CC model reflecting the treatment outcome as initially simulated. Thirteen transverse parameters were measured on each model separately by two investigators. Occlusal contacts were also analyzed.
RESULTS
The measuring method was validated by both investigators arriving at similar results for the effectiveness by which the simulated treatment goals had been clinically achieved. Significant differences (p < 0.05; Wilcoxon signed-rank test) were observed for transfer precision from the casts to the planning software and between the simulated and clinical outcomes. Intense occlusal contacts in the simulations materialized less common (≈ 2%) than ideal contacts (≈ 60%) in the clinical outcomes.
CONCLUSIONS
The effectiveness of achieving the simulated transverse goals was 45% and was generally not found to be better with SmartTrack® than with the previously used Ex30® material. Out of 100 simulated occlusal contacts, 40 will never materialize, and achieving around 60 will adequately ensure a clinically favorable contact pattern.
CLINICAL RELEVANCE
With the caveat that any overcorrection will to some extent reduce the precision, it seems perfectly possible to make deliberate use of overcorrection in current aligner therapies for transverse maxillary expansion or contraction.
Topics: Humans; Malocclusion; Maxilla; Occlusal Adjustment; Orthodontic Appliances, Removable; Palatal Expansion Technique; Retrospective Studies
PubMed: 33474622
DOI: 10.1007/s00784-021-03780-4 -
Heliyon May 2022The periodontal ligaments are very important sensory organ for our daily life such as perception of food size or hardness, determination of jaw position, and adjustment...
The periodontal ligaments are very important sensory organ for our daily life such as perception of food size or hardness, determination of jaw position, and adjustment of masticatory strength. The sensory properties of the periodontal ligament, especially those of the maxillary and mandibular molars, have not yet been fully investigated. Somatosensory evoked magnetic fields (SEFs) can be measured and evaluated for latency and intensity to determine the sensory transmission characteristics of each body parts. However, previous reports on SEFs in the oral region have only reported differences in upper and lower gingival and lip sensations. In this study, the aim was to clarify these sensory characteristics by measuring SEFs during mechanical stimulation of the periodontal ligament in the maxillary and mandibular first molars. Somatosensory evoked magnetic fields were measured in the contralateral hemispheres of 33 healthy volunteers. Mechanical stimulation of the maxillary and mandibular right first molars, and the left wrist was performed with a specific handmade tool. The first peak latency for the mandibular first molars was 41.7 ± 5.70 ms (mean ± SD), significantly shorter than that for the maxillary first molars at 47.7 ± 7.36 ms. The peak intensity for the mandibular first molars was 13.9 ± 6.06 nAm, significantly larger than that for the maxillary first molars at 7.63 ± 3.55 nAm. The locations in the contralateral hemispheres showed no significant difference between the maxillary first molars and mandibular first molars. These locations were more anteroinferior and exterior than that of the wrist, as suggested by the brain homunculus. Neural signals from the mandibular periodontal ligaments pass faster and more intensely to the central nervous system than those from the maxillary periodontal ligaments, and may preferentially participate in adjustment of the occlusal force and the occlusal position.
PubMed: 35620631
DOI: 10.1016/j.heliyon.2022.e09464 -
BDJ Open May 2023To measure the required clinical time and volume of occlusal adjustment when the maxillary cast is positioned in a virtual articulator using one of three methods:...
OBJECTIVE
To measure the required clinical time and volume of occlusal adjustment when the maxillary cast is positioned in a virtual articulator using one of three methods: digitization of a facebow-mounted mechanical articulator (group A), virtual Bonwill triangle (group B) or a 3D face scan (group F).
MATERIALS AND METHODS
In this randomized, triple-blind, crossover trial; 11 participants were enrolled. Every participant had one molar indicated for a single crown restoration. Three crowns were designed and milled for every participant molar totaling 33 crowns. Each of the three crowns was fabricated with the participant's casts virtually mounted utilizing a different method. An impression was taken of the crown in place before occlusal adjustment. The occlusal adjustment was then performed and timed with the three crowns in the different groups. After the occlusal adjustment, an impression of the adjusted crown was taken. The pre-adjustment and post-adjustment impressions were digitally superimposed and the volume difference was measured. The Kruskal-Wallis test was used to compare the groups.
RESULTS
Group A showed the shortest mean adjustment time (3:44.59 ± 3:39.07) followed by group F (4:30.09 ± 2:01.50) and group B (4:35.30 ± 2:32.33). The mean adjustment volume for group A was (28 ± 19.1 mm) followed by group F (30.5 ± 18.8 mm) and group B (40.6 ± 29.5 mm). Different virtual mounting methods had no statistically significant effect on adjustment time (P-value = 0.538) or adjustment volume (P-value = 0.490).
CONCLUSIONS
A simplified approach in virtual articulator mounting appears to be justified in the construction of a single full-coverage prosthesis. Added labor, time and cost of more elaborate virtual mounting methods seem to be counterproductive.
PubMed: 37164989
DOI: 10.1038/s41405-023-00146-8 -
The Journal of Advanced Prosthodontics Dec 2021The aim of this study was to evaluate the efficiency of occlusal and interproximal adjustments of single implant crowns (SIC), comparing a digital cast-free approach...
PURPOSE
The aim of this study was to evaluate the efficiency of occlusal and interproximal adjustments of single implant crowns (SIC), comparing a digital cast-free approach (CF) and a protocol using 3D printed casts (PC).
MATERIALS AND METHODS
A titanium implant was inserted at position of lower right first molar in a typodont. The implant position was scanned using an intraoral scanner and SICs were fabricated accordingly. Ten crowns (CF; n = 10) were subject to a digital cast-free workflow without any labside occlusal and interproximal modifications. Ten other identical crowns (PC) were adjusted to 3D printed casts before delivery. All crowns were then adapted to the testing model, simulating chair-side adjustments during clinical placement. Adjustment time, quantity of adjustments, and contact relationship were assessed. Data were analyzed using SPSS software ( < .05).
RESULTS
Median and interquartile range (IQR) of clinical adjustment time was 02:44 (IQR 00:45) minutes in group CF and 01:46 (IQR 00:21) minutes in group PC. Laboratory and clinical adjustment time in group PC was 04:25 (IQR 00:59) minutes in total. Mean and standard deviation (±SD) of root mean squared error (RMSE) of quantity of clinical adjustments was 45 ± 7 µm in group CF and 34 ± 6 µm in group PC. RMSE of total adjustments was 61 ± 11 µm in group PC. Quality of occlusal contacts was better in group CF.
CONCLUSION
Time effort for clinical adjustments was higher in the cast-free protocol, whereas quantity of modifications was lower, and the occlusal contact relationship was found more favourable.
PubMed: 35003551
DOI: 10.4047/jap.2021.13.6.351 -
Journal of Prosthodontic Research Feb 2021The purpose of this study was to evaluate the occlusal force adjusting ability of implant-supported overdenture (IOD) wearers, as compared with natural teeth and...
PURPOSE
The purpose of this study was to evaluate the occlusal force adjusting ability of implant-supported overdenture (IOD) wearers, as compared with natural teeth and complete dentures.
METHODS
Subjects were those with natural dentition (ND group; 19 subjects), those with implant-supported overdentures (IOD group; 7 subjects), and those with complete dentures (CD group; 14 subjects). Subjects were asked to hold test foods (peanuts and biscuits mounted on a custom-made apparatus with a force transducer) between their anterior incisors (hold phase) and split test foods (split phase). The mean value of the occlusal force during the hold phase (hold force), the peak force rate during the split phase (peak force rate), the time required to split test foods (duration), and the maximum occlusal force in the split phase (split force) were selected as outcomes. Data were analyzed with Wilcoxon's signed rank test, the Kruskal-Wallis test, and multiple regression analysis (Statistical significance levels: 5%).
RESULTS
For peanuts, the peak force rate for the ND group was significantly higher than the IOD and CD groups. The duration of the CD group was significantly longer than the ND and IOD groups. Multiple regression analysis indicated that even with adjustment for age and sex, there were significant differences in the peak force rate between the ND and the IOD, CD groups, and in the duration between the ND and CD group.
CONCLUSIONS
Subjects with IODs showed superior ability to adjust occlusal force, as compared with complete dentures, although it didn't match the natural dentition.
Topics: Bite Force; Dental Prosthesis, Implant-Supported; Denture Retention; Denture, Complete, Lower; Denture, Overlay; Humans; Mandible
PubMed: 32938862
DOI: 10.2186/jpr.JPOR_2019_376