In silico study of cuspid' periodontal ligament damage under parafunctional and traumatic conditions of whole-mouth occlusions. A patient-specific evaluation

The traditional occlusal indicators used in dental practice are articulation papers, Shim-stock foils, elastomeric impression materials, and occlusal wax strips. These static dental materials have been widely believed to have occlusal force descriptive capability. However, modern material studies are challenging the widespread belief that occlusal indicator materials can measure differing occlusal force levels. Chapter two evaluates the force reporting limitations of these static occlusal indicators, and discusses how clinicians subjectively interpret their appearance characteristics to determine differing occlusal force levels. This chapter then compares these non-digital occlusal indicators to the T-Scan computerized occlusal analysis technology, that records and displays precise, quantifiable, relative occlusal force variances, and occlusal contact timing sequences. This digital data aids the clinician in making a more accurate occlusal analysis, and can guide the clinician in the correction of occlusal contact force and timing abnormalities, thereby eliminating the subjectivity that is inherent with traditional occlusal indicator use. To further support the superiority of digital occlusal analysis with the T-Scan technology, a systematic review that compared the many static, non-digital occlusal indicators to quantifiable dynamic digital occlusal indicators is included, as is an articulating paper/foil/T-Scan comparative analysis. A recently published systematic review that evaluated occlusal contacts during Maximum Intercuspation with differing occlusal indicators (both traditional and digital) is also described. Next, this chapter details the diagnostic occlusal capabilities of the T-Scan's digital force and timing data by presenting 2 separate studies that compared measured closure and excursive occlusal contact force and timing parameters in orthodontic and non-orthodontic young adults. A final commentary describes the clinical pitfalls of using maximally invasive Subjective Interpretation to choose occlusal contacts for adjustment, instead of employing minimally invasive T-Scan-guided occlusal contact selection. This last section clearly outlines to the reader that both patients and dentists markedly benefit from implementing the T-Scan 10 occlusal measurement technology.

The traditional occlusal indicators used in dental practice are articulation papers, Shim-stock foils, elastomeric impression materials, and occlusal wax strips. These static dental materials have been widely believed to have occlusal force descriptive capability. However, modern material studies are challenging the widespread belief that occlusal indicator materials can measure differing occlusal force levels. This chapter evaluates the force reporting limitations of these static occlusal indicators, and discusses how clinicians subjectively interpret their appearance characteristics to determine differing occlusal force levels. This chapter then compares these non-digital occlusal indicators to the T-Scan computerized occlusal analysis technology, that records and displays precise, quantifiable, relative occlusal force variances, and occlusal contact timing sequences. This digital data aids the clinician in making a more accurate occlusal analysis, and can guide the clinician in the correction of occlusal contact force and timing abnormalities, thereby eliminating the subjectivity that is inherent with traditional occlusal indicator use. This chapter further details the diagnostic occlusal capabilities of the T-Scan's digital force and timing data, by presenting two separate studies that compared measured closure and excursive occlusal contact force and timing parameters in orthodontic and non-orthodontic young adults. A commentary is included regarding the clinical pitfalls of using maximally invasive, subjective interpretation to choose occlusal contacts for treatment instead of employing minimally invasive, computer-guided occlusal contact selection. This last section clearly illustrates to the reader that both patients and dentists will markedly benefit from the implementation of occlusal measurement technology.

Traumatic occlusion (TO) can cause morphofunctional alterations that interfere in the homeostasis of the periodontium. The aim of this study was to assess the influence of TO on the periodontal repair process for teeth following subluxation. Ninety Wistar rats aged 12weeks were divided into three groups: control (C), subluxation (S) and subluxation with traumatic occlusion (S+TO). Subluxation was created with an impact force of 900cN applied by a tensiometer and TO was created with a direct composite resin filling. Healing after two experimental periods of 7 and 21days was assessed histologically. The Kruskal-Wallis and Dunn post hoc tests were used for group comparison. At 7days, there was a significant increase in periodontal ligament (PDL) width and amorphous fundamental substance, as well as a significant bone area reduction in groups S and S+TO. After 21days, there was a significant PDL width increase in group S+TO, and in the percentage of collagen fibres in group S, whereas group S+TO showed a 52% bone area reduction compared to the same group at 7days. Subluxation with or without TO caused only superficial root resorption. However, only group S+TO showed damage to the repair process of resorbed root areas after 21days. TO can increase damage to the PDL after subluxation and it can also delay the repair process after PDL damage.

The traditional occlusal indicators used in dental practice are articulation papers, shim-stock foils, elastomeric impression materials, and occlusal wax strips. These static dental materials have been widely believed to have occlusal force descriptive capability. However, modern material studies are challenging the widespread belief that occlusal indicator materials can measure differing occlusal force levels. This chapter evaluates the force reporting limitations of these static occlusal indicators and discusses how clinicians subjectively interpret their appearance characteristics to determine differing occlusal force levels. This chapter then compares these non-digital occlusal indicators to computerized occlusal analysis technology that records and displays precise, quantifiable, relative occlusal force variances and occlusal contact timing sequences. This digital data aids the clinician in making a more accurate occlusal analysis and can guide the clinician in the correction of occlusal contact force and timing abnormalities, thereby eliminating the subjectivity that is inherent in traditional occlusal indicator use.

The traditional occlusal indicators used in dental practice are articulation papers, shim-stock foils, elastomeric impression materials, and occlusal wax strips. These static dental materials have been widely believed to have occlusal force descriptive capability. However, modern material studies are challenging the widespread belief that occlusal indicator materials can measure differing occlusal force levels. This chapter evaluates the force reporting limitations of these static occlusal indicators and discusses how clinicians subjectively interpret their appearance characteristics to determine differing occlusal force levels. This chapter then compares these non-digital occlusal indicators to computerized occlusal analysis technology that records and displays precise, quantifiable, relative occlusal force variances and occlusal contact timing sequences. This digital data aids the clinician in making a more accurate occlusal analysis and can guide the clinician in the correction of occlusal contact force and timing abnormalities, thereby eliminating the subjectivity that is inherent in traditional occlusal indicator use.

Excessive occlusal forces and occlusal trauma have been implicated as co-destructive factors for periodontitis in animal models. The objective of this study was to assess the association between occlusal trauma and periodontitis. A total of 167 cases and 205 controls were included for analysis. Occlusal trauma was the exposures of interest and was registered for cases and controls. Additional clinical co-variables were registered as well for further analysis. The association of the exposure and periodontitis was determined by the odds ratio and logistic regression analysis adjusted for confounders. Amalgam restorations, pathogenic occlusion and occlusal trauma were more frequent in cases as compared to controls (P ≤0.05). The distribution of pathogenic occlusion and occlusal trauma was similar according to the stage and class of periodontitis. Logistic regression analysis showed a significant association for cigarette smoking, systemic conditions, amalgam restorations, pathogenic occlusion, and occlusal trauma with periodontitis (P ≤0.05). After adjusting for confounding variables in the model, amalgam restorations and occlusal trauma remained strongly associated with periodontitis (P ≤0.05). Occlusal trauma is strongly associated with periodontitis. Additional long-term prospective studies are necessary to further understand the impact of the occlusal condition and periodontitis.

Comparison of digital technologies for occlusal analysis in dentate arches: A systematic review.

Occlusal contact characteristics of molar teeth with food impaction: Insights from a new digital technique

BackgroundOcclusal analysis is essential in the dental clinical practice. However, the traditional occlusal analysis performed on the two-dimensional level can not directly correspond to the tooth surface with three-dimensional profile, therefore the clinical guidance value is limited.MethodsBy combining the 3D digital dental models and quantitative data from 2D occlusal contact analysis, this study constructed a novel digital occlusal analysis method. The validity and reliability of DP and SA were verified by comparing the results of occlusal analysis of 22 participants. ICC values for occlusal contact area (OCA) and occlusal contact number (OCN) were tested.ResultsResults confirmed the reliability of the two occlusal analysis methods with ICC values of 0.909 for SAOCA, 0.906 for DPOCA, 0.929 for SAOCN and 0.904 for DPOCN. The Bland-Altman plot, paired t-test (tOCN = 0.691, P > 0.05) and Pearson correlation analysis results (R = 0.68, p < 0.001) verified the validity between SA and DP. Then a novel digital occlusal analysis method was constructed, which not only can locate the occlusion contact and provide the quantitative analysis, but also provide a comprehensive description of the resultant force of each tooth and the component forces on the x-, y- and z-axis.ConclusionsThis new occlusal analysis method can obtain quantitative analysis of occlusal contact including contact area and force information simultaneously, which will provide new impetus and greater help for clinical dental treatment and scientific research.

Validity of 3-dimensional reconstruction and simulation of mandibular movement and occlusal contact

Assessment of ramus, condyle, masseter muscle, and occlusal force before and after sagittal split ramus osteotomy in patients with mandibular prognathism

Periodontitis, a chronic inflammatory disease, often causes alveolar bone loss. Neisseria bacilliformis is a Gram-negative bacterium that has been identified in periodontal patients, but its role in periodontitis remains unclear. In the present study, we examined whether N. bacilliformis exacerbates periodontitis in a mouse ligature-induced periodontitis (LIP) model and investigated its underlying molecular mechanism. Topical treatment with N. bacilliformis on maxillary second molar exacerbated alveolar bone loss and worsened epithelial and periodontal ligament damage. Histological analyses showed that N. bacilliformis increases tartrate-resistant acid phosphatase (TRAP)-positive osteoclasts and inducible nitric oxide synthase (iNOS) levels in the gingival tissue. Treatment with N. bacilliformis induced nitric oxide (NO) production in RAW 264.7 cells, which was inhibited by polymyxin B, implying that N. bacilliformis lipooligosaccharide (LOS) is a major etiologic agent in the inflammatory response. Indeed, LOS purified from N. bacilliformis enhanced NO production and iNOS expression, primarily with activating Toll-like receptor (TLR) 4 and partially activating TLR2. LOS administration into the disto-palatal papilla near the molar further aggravated periodontitis in the LIP mouse model. These results suggest that N. bacilliformis is a periodontal pathogen that exacerbates inflammation and alveolar bone loss, with its LOS acting as an important virulence factor via TLR2/4 activation, leading to the production of the inflammatory mediator NO.

In this study, we investigated the effect of photobiomodulation (PBM) using near-infrared light on the dentin and periodontal ligament in a beagle model. We utilized a specific PBM device to irradiate NIR light with a wavelength of 810 nm and an energy density of 80.22 mJ/cm2. The device’s settings were optimized for a frequency of 300 Hz and a 30% duty cycle, allowing precise and controlled light exposure. Through a comprehensive analysis involving micro-computed tomography, scanning electron microscopy, and hematoxylin and eosin staining, we demonstrated increased odontoblast activity at the pulp–dentin interface in PBM-treated samples. This increased activity may be postulated to potentially contribute to alleviating dental hypersensitivity through the differentiation of dental pulp stem cells and the promotion of vascular development within the odontoblast layer. Moreover, our observations also indicated an improvement in the strength and integrity of fibrous connective tissue within the periodontal ligament. These findings highlight the potential of PBM with specific parameters applied using NIR as a valuable treatment method for tooth tissue regeneration. It shows particular promise in the treatment of dental diseases associated with dentin and periodontal ligament damage and offers a new perspective in the management of tooth hypersensitivity and other related dental diseases.

An NIH conference on "Removal of Third Molars" debated the need for removal of asymptomatic impacted teeth with no evidence of pathology but stressed the need for long-range studies. The assumption is that "neglected" impacted third molars (ITMs) will sometime cause serious pathology. Examination of panoramic radiographs of 11,598 patients revealed 1,756 patients with 3,702 impacted teeth; average age 47 years, and an average retention period approximately 27 years. Dentigerous cystic changes occurred in about 30 ITMs (0.81%), internal resorption in 16 (0.43%), periodontal ligament damage and bone loss distal to the 2nd molar 166 times (4.48%), and pressure resorption of the 2nd molar 113 times (3.05%). No great surge in pathology occurred with increasing age. Some type of pathological change can be expected eventually in approximately 12.0% of an impacted 3rd molar population and 1.82% of the general population. A reappraisal of routine removal of ITMs might be indicated.

Protecting the function of periodontal ligament stem cells (PDLSCs) is crucial for bone regeneration in periodontitis. Forkhead box protein O1 (FoxO1) has been previously reported as a crucial mediator in bone homeostasis, providing a favorable environment for osteoblast proliferation and differentiation. Here, we investigated the effect and mechanism of FoxO1 agonists on the osteogenesis of PDLSCs under inflammatory conditions. Here, we screened FoxO1 agonists by detecting their effects on the osteogenic differentiation of PDLSCs. Then, the function of these agonists in bone regeneration was analyzed in the periodontitis model. We found that hyperoside or 2-furoyl-LIGRLO-amide trifluoroacetate salt (2-Fly) promoted osteogenic differentiation under inflammation by simultaneously inhibiting nuclear factor κB (NF-κB) activation, β-catenin expression, and reactive oxygen species (ROS) production. Moreover, local injection of hyperoside or 2-Fly rescued the expression of FoxO1 and runt-related transcription factor 2 (Runx2) in vivo, alleviating alveolar bone loss and periodontal ligament damage. These findings suggested that FoxO1 agonists exerted a protective effect on osteogenesis in PDLSCs, as a result, facilitating bone formation under inflammatory conditions. Taken together, FoxO1 might serve as a therapeutic target for bone regeneration in periodontitis by mediating multiple signaling pathways.