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Purpose: To compare the sta6c and dynamic occlusion of all-ceramic single crowns designed by mechanical and virtual ar6culators, by evalua6ng the accuracy of occlusal contacts of prostheses designed by virtual ar6culators and the feasibility of clinical applica6on of CAD/CAM virtual ar6culators. Materials and Methods: Nine subjects with an average age of 27 years who needed crown repair were recruited. AJer prepara6on of the all-ceramic crowns, two zirconia crowns were designed and fabricated through digital procedures and tradi6onal methods. The intraoral scanner, Geomagic soJware, and T-Scan analyzer were used to analyze the occlusal contact points, areas, and the occlusal force percentage peak before the treatment and aJer the two crowns were temporarily fixed. Results: There was a significant difference in the number of occlusal contact points and areas between the mechanical group and control group (preopera6on group), but there was no obvious difference between the virtual group and control group. The occlusal contact overlapping areas of the virtual-control group were significantly larger than those of the mechanicalcontrol group. The occlusal force percentage peak of the tested teeth was slightly larger in the mechanical group than in the virtual group. Conclusions: The posterior single crown designed by a virtual ar6culator restored the intercuspal occlusal beSer than one designed by a mechanical ar6culator, and it produced less dynamic occlusal interference. This finding suggests that virtual ar6culators can provide guidance for the design and adjustment of the occlusal surface of posterior single crown prostheses. [ABSTRACT FROM AUTHOR]

Objective Materials and Methods Results Conclusion Clinical Significance This study aimed to present three indicators that represent the proximal contact area gap change under intercuspal occlusion and to see if and how these indicators influence food impaction with tight proximal contact.Ninety volunteers were recruited for bite force measurement and intraoral scanning. Three‐dimensional surface data and buccal bite data were obtained for 60 impacted and 60 non‐impacted teeth. The scanning data were imported into the Geomagic Studio 2013 to measure three indicators, which included the gap change maximum (Δdm, μm), the buccolingual position of Δdm (P), and the gap expanded buccolingual range (S, mm). The difference between two groups of three indicators and their relationship with food impaction with tight proximal contact were analyzed by the t test, the Pearson chi‐squared test, the nonparametric Mann–Whitney U test, and the binary logistic regression analysis (a = 0.05).All indicators (Δdm, P, and S) were statistically different (p < 0.001, p = 0.002, and p < 0.001) in the impacted and non‐impacted groups. Food impaction with tight proximal contact was affected by Δdm and S (p < 0.001, p = 0.039), but not by P (p = 0.409).The excessive increase of the gap change maximum and the gap expanded buccolingual range under bite force promoted the occurrence of food impaction with tight proximal contact.The use of intraoral scanning to measure the characteristics of the proximal contact area gap change under bite force may help to deepen our understanding of the pathogenesis of food impaction with tight proximal contact. Importantly it can provide a reference basis for individualizing and quantifying occlusal adjustment treatment. [ABSTRACT FROM AUTHOR]

Background: Older adults who have undergone surgery for oral tumors are at increased risk of impaired masticatory rhythm. This study investigated the correlations between masticatory rhythm, objective masticatory performance, and subjective masticatory performance as well as factors related to masticatory rhythm. Methods: The participants were 44 adults (24 men, 20 women; age range 42~90 years old) who had undergone maxillectomy, mandibulectomy, or glossectomy and were rehabilitated with a maxillofacial prosthesis. The number of functional contact teeth pairs was confirmed by intraoral examination. Chewing rate, cycle duration, coefficient of variation (CV) for cycle duration (reflecting the stability of masticatory rhythm), and mixing ability were measured simultaneously using a mastication movement rhythm tracking device during gum chewing. Maximum occlusal force was measured using the dental prescale system. Patients' perception of chewing ability was rated using a questionnaire. Results: The Spearman's rank correlation test revealed that mixing ability, patient-rated masticatory scores, cycle duration, CV for cycle duration, and maximum occlusal force showed significant correlations with chewing rate. Multiple linear regression analysis identified mixing ability and the CV for cycle duration as significant predictors of masticatory rhythm. Conclusions: Factors associated with a faster chewing rate were higher mixing ability and masticatory scores, greater maximum occlusal force, shorter cycle duration, and smaller CV for cycle duration. Stable masticatory rhythm and mixing ability are significant predictors of chewing rate. Poor masticatory performance and unstable masticatory rhythm can result in slower chewing and thus a higher risk of inadequate dietary intake. [ABSTRACT FROM AUTHOR]

Background: Digital technologies enable the accurate replication of occlusion, which is pivotal for stability in maximum intercuspation and dynamic occlusion. CAD softwares generates standardized occlusal morphologies requiring significant adjustments. The consideration of individual mandibular movements during restoration leads to better functional integration. This pilot study evaluates the efficacy of a novel, fully digital protocol for occlusal analysis recording in prosthodontics. Methods: Patients needing single or multiple metal-free restorations were included. Teeth underwent horizontal finish line preparation, while restorations on implants were either directly screwed or used multi-unit abutments. A digital impression (Trios 3 Intraoral Scanner) captured the mouth's elements. Dynamic occlusion was recorded via Patient Specific Motion (PSM). After the placement and functionalization of temporary restorations, subsequent scans included various elements, and CAD software (Dental system) was used for the restoration design. Restorations were milled in monolithic zirconia, pressed from CAD/CAM-milled wax, and sintered. Results: An evaluation of 52 restorations in 37 patients indicated high accuracy in restorations manufactured via the fully digital workflow. Monolithic zirconia was predominantly used. Subtractive (17.3%) and additive (7.7%) occlusal adjustments were mainly chairside. Conclusion: This study underscores the efficacy of meticulous verification measures and a centric contact system in reducing the need for clinical occlusal refinements in prosthetic restorations. [ABSTRACT FROM AUTHOR]

Objectives: Single denture rehabilitated patients have negative appraisals regarding oral function, mostly associated by stability and retention issues regarding mandibular prosthetics. Therefore, this study assessed patients' occlusal equilibration, muscle activity, and oral health-related quality of life (OHRQoL) receiving milled removable or fixed mandibular implant retained prostheses. Materials and methods: Twenty-two edentulous mandibular ridges patients were randomly distributed into two groups based on the definitive prosthesis received. Group I: Removable mandibular implant-supported overdenture, Group II: Implant retained fixed prosthesis. Occlusal equilibration was evaluated utilizing Occlusense, muscle activity via Electromyograph (EMG) at delivery, after one, and three months. The OHRQoL was evaluated by Oral Health Impact Profile questionnaire (OHIP-19) before delivery and after follow-ups. Data were collected, tabulated, and analyzed, utilizing independent t-test and One-way ANOVA followed Tukey's post-hoc test. Significance level set at P ≤ 0.05. Results: Groups I &II showed significant improvement in occlusal equilibration, muscle activity and OHRQoL. Group II demonstrated significantly higher improvement than group I in occlusal equilibration associated with muscle activity after 1 month, and in functional limitations domain in OHRQoL questionnaire after 3 months. Conclusion: Implant retained mandibular prosthesis showed improvement in occlusal equilibration, muscle activity, and OHRQoL regardless of prosthesis type employed. Fixed implant-supported prosthesis revealed better outcomes than removable mandibular implant-supported overdenture concerning occlusal equilibration, muscle activity, and OHRQoL regarding functional limitations. Clinical relevance: Implant retained mandibular prosthesis is one of best treatment options for single mandibular completely edentulous patients, as dental implants improved occlusal equilibration, muscle activity, and OHRQoL. [ABSTRACT FROM AUTHOR]

Background: Occlusal interferences lead to changes in mandibular kinematics to compensate and improve function. However, the effects of different types of eccentric disturbance on the comminution capacity are not known. Objective: To determine the immediate effect of eccentric occlusal interferences on masticatory performance. Methods: This crossover clinical trial included 12 healthy dentate subjects aged 25.2 ± 3.3 years who were randomly submitted to seven types of occlusal interference: unilateral and bilateral laterotrusive and mediotrusive, protrusive, dummy and control (no interference). The interference forms were planned in a semi‐adjustable articulator, fabricated with composite resin and adhered to the mandibular first molars such that subjects' maximum intercuspation was maintained. Masticatory performance and the chewing rate during 20 cycles were evaluated during subjects' comminution of silicone test food under one interference condition per test day; the multiple sieve method was applied to the comminuted particles. The interference was removed upon test completion, and a 1‐week washout period was applied between tests. Results: Comminuted median particle sizes were larger under unilateral (4.94 ± 0.41 mm) and bilateral (4.81 ± 0.49 mm) laterotrusive, bilateral mediotrusive (4.65 ± 0.50 mm) and protrusive (4.83 ± 0.54 mm) interferences (p <.05) than under the control (4.01 ± 0.52 mm) and dummy (4.18 ± 0.58 mm) conditions (p <.05). Only unilateral and bilateral laterotrusive interferences narrowed the comminuted particle size dispersion (p <.05). The chewing rate did not differ among conditions (p =.1944). Conclusion: Artificial eccentric interferences had an immediate adverse effect on masticatory performance by resulting in larger comminuted particles. Clinical trial registration: Brazilian Registry of Clinical Trials (RBR‐8g5zfg8). [ABSTRACT FROM AUTHOR]

Purpose: To investigate the influence of occlusal interference using finite element analysis (FEA). Materials and Methods: The FEA model designed for this study centered on an all-ceramic, bilayered, fixed partial denture (FPD) retained on the maxillary first premolar and first molar, with the second premolar replaced by a pontic. The surrounding structures--such as the neighboring teeth, antagonists, and periodontium--were modeled. Four different loading cases were designed at occlusal interferences of 0, 8, 12, and 24 µm and were loaded by a simulated bite force of 300 N. Principal and von Mises stresses, as well as strain, were evaluated for all included structures. Results: For interferences of 12 and 24 µm, failure-relevant tensile stresses in the veneering layer were observed at the occlusal surfaces. Stress found in the zirconia FPD did not reach fatigue or flexural strength for any test load. Conclusion: Peak tensile stress was observed in close proximity to occlusal contact points, increasing with increasing occlusal interference. The FEA results suggest that the majority of occlusal stress is absorbed by the deformation of the periodontal ligament. Framework failure caused by the simulated interferences was not expected. Surface defects may ultimately lead to failure due to fracture or chipping, especially in cases of weaker ceramics or veneering. [ABSTRACT FROM AUTHOR]

Purpose: To assess (1) whether an occlusal splint (OS) or mandibular advancement splint (MAS) allowed better sleep quality and was more comfortable in individuals with sleep bruxism (SB); and (2) the relationship between sleep quality, comfort, and reduction in RMMA related to SB. Materials and Methods: Polysomnographic data from 21 SB subjects (mean ± SD age 25.6 ± 4.5 years) collected in two previous studies were compared. Morning self-reports on sleep quality and comfort of the oral device, polysomnographic data, and RMMA index data from no-device nights were compared to nights using an OS or MAS. The reduction ratio of the RMMA index was calculated for both devices. A responder to the oral device was identified when the RMMA index was less than 2 and when it showed a reduction of at least 50% from the no-device control night. Results: Self-reports for sleep quality and comfort of the oral device showed a mild advantage of the OS when compared to the MAS (r2 = 0.47, r2 = 0.32; P = .01). In responders, the MAS induced a greater reduction in the RMMA index (P = .03) than the OS. Conclusions: In the short term, the comfort of the oral device seemed to influence sleep quality in SB individuals. However, despite the slightly higher degree of comfort offered by the OS, the MAS induced a greater effect on the RMMA index. [ABSTRACT FROM AUTHOR]

How to ensure dental stability in new positions and reduce the likelihood of relapse is a major clinical concern in the orthodontic field. Occlusal contacts between arches may affect the transmission of masticatory forces, thereby influencing the biological response of the periodontal and the oromandibular system. Occlusion factors that may influence the stability after orthodontic tooth movement (OTM) remain largely unknown. Hence, this research was conducted in order to investigate the influence of different occlusal contact patterns on tooth stability and oromandibular system including the masseter muscle and the temporomandibular joint following OTM. By modifying the occlusal surfaces, in vivo animal study models with distinct occlusal patterns corresponding to clinical circumstances were established. The relapse distance of teeth and the level of inflammatory factors in the gingival cervical fluid were analyzed. We also closely observed the histological remodeling of periodontal tissue, masseter tissue, and joint tissue after one week of relapse. Moreover, genes expression in the alveolar bone was analyzed to illustrate the potential biological mechanisms of relapse under the influence of different occlusal contact patterns following OTM. Different occlusal contact patterns after OTM in rats were established. The intercuspation contact between cusp and fossa group exhibited the lowest level of relapse movement, inflammatory factors and osteoclast activity (P < 0.05). On the other hand, groups with interferences or inadequate contacts exhibited more relapse movement, and tend to promote inflammation of periodontal tissue and activate bone resorption (P < 0.05). Adequate occlusal contacts without interference may enhance tooth stability and reduce the likelihood of relapse. After active orthodontic treatment, necessary occlusal adjustment should be made to achieve the desired intercuspation contact relationship and ensure adequate contact between the arches. The elimination of occlusal interferences is crucial to achieving optimal stability and promoting overall healthy condition of the oromandibular system. [ABSTRACT FROM AUTHOR]

Background and Objectives: Despite the identified benefits of early implant loading, studies have questioned its advantages compared to delayed loading in edentulous patients. This study aimed to evaluate clinical peri-implant parameters and marginal bone loss around early placed and loaded mandibular implant overdentures with a 60-month follow-up. Materials and Methods: In this prospective cohort study, 43 patients were enrolled to receive 86 early loading sub-crestal dental implants through prosthetic guides. Implant overdentures were supported by two isolated implant locator attachments between two mental foramens. Clinical peri-implant parameters, including plaque index (PI), bleeding index (BI), peri-implant pocket depth (PIPD), and marginal bone loss (MBL) were evaluated using standardized techniques at 1, 12, 24, 36, 48, and 60 months follow-up. At 60 months, complications associated with implant overdentures (IOD's) were noted. The mean comparison of peri-implant clinical parameters was performed through ANOVA test. A p-value of ≤0.05 was taken as significant. Results: Out of the total 43 enrolled patients, 8 patients were lost during follow-up; as a result, 35 patients completed the 5 years follow-up. The mean values of PI, BI, and PIPD increased with no statistical difference (p > 0.05). For marginal bone loss, an increase in the mean values was noted at different time intervals with statistical differences (p < 0.001). The most common complications noted were loosening of the abutment, occlusal adjustment, retentive locator loosening and replacement, and relining of the denture. Conclusions: Early placement of IODs failed to prevent bone loss over time and was associated with complications, predominantly consisting of abutment loosening, occlusal adjustments, broken retentive locator components, relining, and rebasing. [ABSTRACT FROM AUTHOR]

Introduction: Bruxism is a spectrum of masticatory muscles activities. According to the recent evidence and international consensus, there is no indication to treat bruxism unless clinical consequences are present. The aim of the present study was to investigate the approach of Italian dentists to bruxism in their clinical practice. Methods: An anonymous online survey was developed, composed by 26 items grouped into five sections: (1) Characteristics of the respondent (Q1–Q6); (2) Bruxism frequencies (Q7–Q11); (3) Bruxism assessment (Q12–Q15); (4) Bruxism management (Q16–Q20); (5) Occlusal splints therapy (Q21–Q26). Results: A total of 384 practitioners, including specialists and non‐specialists, participated in this survey. The majority of the respondents reported that 1–3 out of ten patients presented with bruxism. The diagnosis is mainly performed with non‐instrumental methods, and facial pain and dental wear are the major clinical consequence associated with bruxism. Almost the entire sample of respondents report to offer occlusal splints to bruxism patients, and 41% refer to perform occlusal adjustments. Almost half of the respondents have never proposed any form of cognitive‐behavioural therapy. Conclusion: The results of the current survey highlighted several inconsistencies in Italian dentists' approaches to bruxism, suggesting the need for better education of practitioners and for the development of a standardized protocol to assess and manage bruxism in dental practices. [ABSTRACT FROM AUTHOR]

Purpose: Anterior segmental osteotomy (ASO) following the surgery-first approach is a long-established treatment modality to resolve lip protrusion in patients with skeletal class II patterns. However, the indications and effectiveness of ASO still remain uncertain. The objective of this study is to investigate the effectiveness of ASO in Asian skeletal class II patients by evaluating the skeletal and soft tissue changes and analyzing pre-treatment variables that determine successful outcomes in occlusal as well as esthetic aspects. Methods: The lateral cephalograms of 44 skeletal class II patients who underwent ASO and orthodontic treatment for resolving lip protrusion were retrospectively collected. Hard and soft tissue variables of two groups, normalized (NG) and unnormalized (UNG) ANB after treatment were compared and analyzed. The rotational effect of the anterior segment on the hard and soft tissue was also investigated. Results: ASO was successful in correcting the skeletal class II relationship and lip protrusion (ΔANB − 2.3°, 4–5 mm lips retraction) in most cases. However, for patients with severely camouflaged skeletal class II incisors involving a large ANB and SNA, a large ANB still remained post-treatment. The study also found that rotation of the upper and lower anterior segments further augmented the amount of lip retraction. Conclusions: ASO was found to successfully correct ANB of skeletal class II patients under the following conditions (ANB 5.3° ± 1.5°, SNB 77.3° ± 4.5°, U1 to FH 115° ± 7.5, L1 to FH 48.0° ± 4.6). However, patients with larger ANB and SNA values may require bi-maxillary surgery. In addition, ASO has limitations in correcting gummy smile in cases of extreme maxillary excess. For patients requiring a large amount of lip retraction, rotation of the anterior segment may be beneficial in conjunction with bi-maxillary surgery. [ABSTRACT FROM AUTHOR]

Purpose: This review aimed to highlight the aetiology and risk factors of food impaction along with the treatment in each case. Materials and Methods: A search was conducted in PubMed from 1947 to March 28, 2023. The search terms utilised included (food impaction) OR (interdental impaction). No filter was applied. Articles related to the classification, aetiology, treatment, and associated factors of food impaction in dentistry and published in English or with an abstract in English were selected. Results: A total of 72 articles were included in the review, which revealed the variety and complexity of aetiological factors and treatment of food impaction in dentistry, as well as the heterogeneity of previous studies. Based on the aetiology, different treatment plans and management should be considered. Conclusion: This review indicated the need to identify the pathology of food impaction before treatment. Considering the causal factors of food impaction -- including proximal contact loss, occlusal disharmony, morphological deformity, positional abnormality, and interdental papillae loss -- different management approaches such as restoration, occlusal adjustment, orthodontic, nonsurgical or surgical treatment could be applied. Further clinical and experimental research is warranted to address the prevention and treatment of food impaction in dentistry. [ABSTRACT FROM AUTHOR]

Objectives: To compare the survival and complication rates of posterior screw‐retained monolithic lithium disilicate (LS2)/veneered zirconia (ZrO2) single implant crowns (SICs), as well as analyze the occlusal changes observed during a 3‐year follow‐up period. Materials and Methods: Thirty‐three patients were included and randomly divided into two groups. The test group consisted of 17 patients who received monolithic‐LS2–SIC, while the control group consisted of 16 patients who received veneered‐ZrO2‐SIC. Implant/prosthesis survival rates, technical complications, peri‐implant soft tissue conditions, and quantitative occlusal changes of SIC (obtained by the intra‐oral scanner and analyzed in reverse software Geomagic Control 2015) were assessed at 1‐ and 3‐year follow‐ups. Bone loss and Functional Implant Prosthodontic Score (FIPS) were evaluated at a 3‐year follow‐up. Results: After a 3‐year follow‐up period, one patient dropped out of the follow‐up. No implant loss was observed. One crown was fractured, resulting in prosthesis survival rates of 93.75% for the monolithic group and 100% for the veneered group. A technical complication rate of 25% (4/16) was observed in the veneered group (p =.333). No significant differences in the marginal bone loss were observed at the 3‐year follow‐up (0.00 (−0.22, 0.17) mm versus 0.00 (−0.12, 0.12) mm, p =.956). The total FIPS scores for the test group were 9.0 (9.0, 9.0), while the control group received scores of 9.0 (8.0, 10.0) (p =.953). The changes in mean occlusal clearance were 0.022 ± 0.083 mm for the test and 0.034 ± 0.077 mm for the control group (at 3 years, p =.497). The changes in occlusal contact area were 1.075 ± 2.575 mm2 for the test and 1.676 ± 2.551 mm2 for the control group (at 3 years, p =.873). Conclusion: After a 3‐year follow‐up, screw‐retained monolithic LS2 and veneered ZrO2 SIC demonstrated similar survival rates. The occlusal performance of implant prostheses needs to be closely examined during follow‐up, and appropriate occlusal adjustments need to be considered. [ABSTRACT FROM AUTHOR]

The integration of virtual surgical planning (VSP) for the treatment of skeletal, dental, and facial abnormalities and obstructive sleep apnea (OSA) with maxillofacial surgery has catapulted surgical planning. Although reported for treating skeletal-dental abnormalities and dental implant surgery, a paucity of knowledge existed reporting the feasibility and resultant outcome measures when VSP was employed for planning maxillary and mandibular surgery for OSA patients. The surgery-first approach is at the forefront of advancing maxillofacial surgery. Case series reporting success with the surgery-first approach for patients with skeletal-dental and sleep apnea patients have been reported. In sleep apnea patients, clinically significant reductions in apnea-hypopnea index and improvement of low oxyhemoglobin saturation have been achieved. More so, significant improvement in the posterior airway space at the occlusal and mandibular planes were achieved, while preserving aesthetic norms as measured by tooth to lip measurements. VSP is a feasible tool used for predicting surgical outcome measures in maxillomandibular advancement surgery for patients with skeletal, dental, facial, and OSA derangements. [ABSTRACT FROM AUTHOR]

Objective: This randomized clinical trial aimed to compare the efficacy of Erich arch bars (EAB) and intermaxillary fixation (IMF) screws in reducing mandibular fractures during open reduction and internal fixation (ORIF). Methods: A total of 28 patients with mandibular fractures were randomly allocated to either the EAB group or the IMF screws group. The study evaluated various parameters including occlusal stability, complications, duration of application, oral hygiene status, quality of life, and patient characteristics. Results: The study found no significant differences in occlusal stability between the EAB and IMF screw groups. However, the application and removal times were longer for EAB compared to IMF screws. The EAB group showed a higher presence of biofilm on teeth, indicating poorer oral hygiene status compared to the IMF screws group. In terms of quality of life, patients in the EAB group reported worse results in the "handicap" domain at the 15th postoperative day. No significant differences were observed in other quality-of-life parameters. Patient characteristics were well distributed between the two groups, enhancing the reliability of the results. Conclusion: Both EAB and IMF screws demonstrated comparable occlusal stability for minimally displaced mandibular fractures. However, IMF screws offered advantages such as shorter application and removal times, better oral hygiene maintenance, and potentially improved quality of life in the "handicap" domain. Further studies with larger sample sizes are necessary to validate these findings and explore the stability of IMF methods in cases requiring postoperative malocclusion correction or prolonged IMF. [ABSTRACT FROM AUTHOR]

Purpose: To evaluate correlations of arch size and sex with the interocclusal rest distance (IORD), as well as to estimate proportional variance. Materials and Methods: A total of 106 participants were examined. The participants, 38 men and 68 women, were aged 22 to 30 years, were fully dentate, had no signs of abnormal abrasion, and had intact posterior occlusal contacts. Measurements of interocclusal rest distance and tragus-incisal distance were recorded, and the rest angle created between the tragus-incisal distance in maximum intercuspation and in resting vertical dimension were calculated according to the cosine formula. Correlation between the size of the mandible (tragus-incisal distance, mean of left and right sides) and the IORD were calculated using Pearson correlation coefficient. Correlations for sex (calculated separately for male and female) and rest angle were also assessed. Results: The mean (SD) tragus-incisal distance values were 123.38 (6.77) mm for all participants, 120.01 (4.64) mm for women, and 130.72 (5.24) mm for men. The mean (SD) IORD values were 2.76 (1.3) mm for all participants, 2.13 (0.9) mm for women, and 3.87 (1.17) mm for men. The mean (SD) rest angle values were 1.26 (0.55) degrees for all participants, 1.02 (0.41) degrees for women, and 1.7 (0.49) degrees for men. Pearson correlation coefficient between IORD and tragus-incisal distance was significant (P < .05). According to t test, there was a significant difference between men and women for IORD, tragus-incisal distance, and rest angle (P < .01). Conclusion: A correlation exists between IORD and arch size. A statistically significant difference was found between men and women for IORD and arch size values. [ABSTRACT FROM AUTHOR]

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The article discusses the importance of precise jaw records in prosthodontics for maintaining oral health and function. It reports the need for individualized recording using a face bow due to anatomical variations. It highlights the hinge-like jaw movement during the occlusal-to-rest position transition, which is crucial. It emphasizes the need for meticulous capture and transfer of the hinge axis for precise articulation in dental practice.

Understanding the clinical anatomy of the head is essential for performing proper inferior alveolar nerve (IAN) block anesthesia to facilitate invasive dental procedures in camels. However, osteometric data related to the IAN in camels are lacking. This study was carried out to accurately locate the mandibular foramen (MF) and the course of the IAN in the camel head and to establish an approach for its localization in clinical practice. To achieve these aims, eight osteometric measurements were used to determine the location of the MF in relation to its surrounding structures in six cadaveric skulls of adult camels. Four camel heads were dissected, and the course of the IAN inside the mandibular canal was studied. In addition, four heads were used as a trial for the extraoral approach to the IAN block using contrast radiographs based on established metric indices. Dissection of the four camel heads revealed that the MF was located near the intersection of two lines passing through the occlusal surface of the mandibular cheek teeth and at the midpoint of the zygomatic process of the temporal bone. Significant differences were not observed between the right and left mandibles. Successful deposition of the contrast medium near the MF was observed in all examined specimens. This study reports a new, simple approach to reaching the IAN at the MF. However, further clinical validation of the proposed technique is required. [ABSTRACT FROM AUTHOR]

Introduction: This study tested orthognathic surgery effects on temporomandibular joint (TMJ) compressive stresses. Methods: Pre‐ (T1) and post‐surgery (T2) cone‐beam computed tomography images were collected from consenting subjects aged ≥15 years. Anatomical data were used to measure surgical changes in anteroposterior mandibular position and occlusal plane angle (FH‐OP), estimate condylar loading areas (mm2) and calculate T1 and T2 TMJ and jaw muscle forces (N) during canine biting via numerical modelling. Analysis of covariance tested for sex and biting angle differences in T2 − T1 TMJ compressive stresses (TMJ force/loading area, MPa). Principal component analyses identified jaw muscle forces that accounted for changes in T2 − T1 TMJ loads. Regression analyses tested the correlations between surgical changes in mandibular position, FH‐OP, TMJ loads and muscle forces. Results: Of 148 cases screened, 28 females and 16 males provided complete records. Condylar loading areas were significantly smaller (P =.024) for females vs males (124 ± 5 vs 144 ± 7 mm2). T2 − T1 differences in TMJ compressive stresses varied by surgical change, biting angle and sex. Overall, the largest increases in TMJ compressive stresses post‐surgery were for females with mandibular setbacks where FH‐OP angle decreased. T2 − T1 changes in jaw muscle forces had moderate (ipsilateral, λ = 4.59; η2 = 0.071) to large (contralateral, λ = 1.49; η2 = 0.31) effects on TMJ loads. Conclusions: T2 − T1 differences in TMJ compressive stresses during canine biting were affected by surgical changes in mandibular position and occlusal plane angle, biting angle and sex. Surgical changes altered jaw muscle forces for the same biting conditions and, thus, affected TMJ loads and compressive stresses. [ABSTRACT FROM AUTHOR]

ABSTRACT Objective: The present study analyzed the biomechanical behavior of the generated stress on the external surface of the rehabilitation elements (implants, components and infrastructures) according to different occlusion patterns on a fixed partial denture on osseointegrated implants. Method: The experimental groups varied according to the location of the occlusal load applied to the Fixed partial denture, with a total occlusal load of 750N in all groups, opting for greater loads on the occlusal table of the molar in relation to the premolar. This evaluation was performed by the finite element method with simulations by the AnsysWorkbench 16.0 Software program. Results: The results analyzed for implants and their components showed that the more posterior the occlusal loading, the greater the stress developed (group 4), always in the connection area between the prosthetic component and the implant, as this location can induce greater screw loosening. The results analyzed for the infrastructures showed that the most distributed occlusal loading possible (group 1) is the best situation for generating less stress. However, even in group 3 which obtained the highest stresses in the critical area of the prosthetic connection, the zirconia flexural strength values generated were not worrisome. Conclusion: It can be concluded that the occlusal adjustment of Fixed partial dentures are preponderant and decisive factors for correct biomechanics and preservation of the system in the long term in order to avoid possible damage and/or failures, and exert significant and notorious differences in the behavior of all structures studied herein.

Summary: Masticatory muscle activity during sleep has been considered independent of variations in the structural characteristics of the dental occlusion. However, scientific evidence contradicting an occlusal causal role is missing. The purpose of this study was to test the null hypothesis that sleep bruxism (SB) is independent of the presence of occlusal interferences. A total of 17 healthy female subjects (mean [SD] age 24.9 [4.1] years) presenting with SB, and randomly divided into two groups, were evaluated after receiving either elimination of occlusal interferences (Test group) or elimination of sharp margins without change in occlusal contacts (Control group). Audio‐video polysomnography (PSG) recordings were undertaken before and after treatment (mean [SD] duration 14.4 [3.8] months). Two subjects in each group (< 2 rhythmic masticatory muscle activity [RMMA]/h) were excluded for statistical analysis. During the total sleep time (TST), the Test group exhibited a higher reduction in frequency of episodes per hour than the Control group (p < 0.05). The reduction in duration of episodes was also higher in the Test group during the TST. The Test group presented an increase in sleep stage N3 (p < 0.05) at the final PSG when compared with the initial PSG, and a higher percentage of N3 (p < 0.05) at the final PSG when compared to the Control group. Elimination of occlusal interferences resulted in a significant reduction of masseter and temporal muscle activity during sleep in females presenting with SB. Based on these results, the null hypothesis is rejected. The hypothesis of occlusal interferences as a risk factor for SB is still patent. [ABSTRACT FROM AUTHOR]

Background: With the introduction of high-tech appliances, anchorage devices, and improved patient awareness of the risks associated with maxillofacial surgery, treating complex situations with orthodontic treatment has become more difficult in recent years. This study was conducted to demonstrate that orienting the occlusal plane, all the dental, skeletal, and soft tissue parameters, would be improved and to find which of these parameters could be correlated with the steepness of the occlusal plane. Materials and methods: This was a retrospective study including 40 cephalometric interpretations for patients who were planned for four-unit extractions (20 cephalometric radiographies before treatment and 20 after finishing the treatment). All were treated in the same orthodontic clinic with the same protocol using the McLaughlin–Bennett–Trevisi (MBT) prescription, with 22 slots and one-step retraction following four-unit extraction based on temporary anchorage devices (TADs). Results: There was no significant change in the canting of the occlusal plane, and it remained relatively stable from 6.31° to 7.55°, while all the soft tissue-related cephalometric measurements were reduced significantly, except the nasolabial angle, as the relation of the upper and lower lip to the esthetic line of Ricketts' (E-Line) was reduced by 2.91 and 2.46°, respectively; furthermore, the angle of convexity was reduced from 10.92° to 9.79°. Besides, the upper incisor display was reduced by 0.38° Conclusions: Both the Frankfort mandibular angle and upper-incisor-to-Frankfort horizontal plane were significant parametric factors associated with profile change after extraction treatment having a positive 0.01-level Pearson association with occlusal plane steepness. Therefore, using the MBT prescription with TAD-based retraction is one of the favorable methods for the management of complex cases. [ABSTRACT FROM AUTHOR]

Background: Mandibular condyle remodeling and displacement are post-orthognathic surgery concerns that can potentially lead to occlusal issues after bilateral sagittal split ramus osteotomy. This retrospective study examined the relationship between condylar volume changes and position alterations after surgery in patients with skeletal class II and III malocclusions using cone-beam CT. Methods: The study included 16 patients (6 with Class II malocclusion, 10 with Class III malocclusion) who underwent bilateral sagittal split ramus osteotomy at Chonnam National University Hospital. Cone-beam CT data were collected at three specific time points: before surgery, immediately after surgery, and approximately 6 months post-surgery. Mandibular movement was measured using InVivoDental 5.4.6. ITK-SNAP 3.8.0 was used to assessed condylar volume changes post-surgery. Condyle positions were evaluated in four parts with RadiAnt DICOM Viewer 4.6.9. Statistical analyses were performed using the SPSS version 23. Results: Considering both Class II and III malocclusion, a 2.91% volume reduction was noted immediately and at 6 months after surgery. Both Class II and III cases demonstrated a decrease in superior joint space by -0.59 mm and medial joint space by -1.09 mm. No significant correlation was found between this process and condylar volume change. Conclusions: The mandibular condyle volume decreased, and superior-medial movement of the condyle was detected in patients with Class II and III malocclusion immediately and at 6 months after surgery with no volume-position correlation. [ABSTRACT FROM AUTHOR]

The article discusses the importance of aligning the occlusal plane in dental laboratory work, emphasizing the role of prosthetic reference planes such as the Campersche Ebene and Frankfurter Horizontale. It states that the choice between them is determined by the treating dentist and is crucial for achieving accurate prosthetic outcomes. It highlights the significance of understanding and differentiating between these reference planes in dental technology.

Aim To clinically compare treatment of TMDs using hard occlusal stent constructed by CAD/CAM technology, low-level laser therapy (LLLT) and a combination of hard occlusal stent and LLLT. Patients and methods Twenty-one adult patients have suffered from chronic myofascial pain for at least three months. The patients were randomly divided into three equal groups based on the kind of treatment. Group A: Patients have received hard occlusal stent constructed by CAD/CAM technology. Group B: Patients have received LLLT. Group C: Patients have received a combination of hard occlusal stents constructed by CAD/CAM technology and LLLT. Clinical evaluations were done using Visual Analogue Scale (VAS) evaluation before therapy, at the fifth week, the third and sixth months after the onset of the study period. Data at the end of the trial was gathered, tabulated and statistically analyzed. Results Clinical results revealed that all three groups showed a general improvement in TMDs symptoms throughout the study period. The improvement was significant in all the study group periods. There was no statistically significant difference between the groups. Conclusions It has been established that the CAD/CAM occlusal stent, LLLT, and combination of CAD/CAM occlusal stent and LLLT enhances patient satisfaction and pain alleviation in individuals with TMDs. [ABSTRACT FROM AUTHOR]

Copyright of West China Journal of Stomatology is the property of Sichuan University, West China College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Horizontal condylar guidance (HCG) is registered by protrusive interocclusal records but in nonarcon articulators, these records can affect the accuracy. The present study aimed to evaluate the effect of a novel rotation coordinating device (RCD) on condylar guidance setting with protrusive interocclusal records. Materials and Methods: The study was designed as a comparative in-vitro investigation. Stone maxillary and mandibular casts were mounted on a fully adjustable instrument as the patient. Duplicate casts were mounted on an arcon and a nonarcon articulator with corresponding face bow records and in maximum intercuspation relation. Five different condylar guidance inclinations for both sides (20°, 30°, 40°, 50°, and 60°) were set on the fully adjustable instrument and 16 protrusive interocclusal records were established at each setting. HCG was set for arcon, nonarcon articulators, and nonarcon articulators with RCD. Data were analyzed using one-sample t-test to compare with actual HCG and one-way analysis of variance (α =0.05). Results: Mean HCG for studied articulators was 35.40 for arcon, 30.31 for nonarcon without RCD, and 35.61 for nonarcon with RCD which were significantly different from actual HCG (P < 0.05). HCG of the nonarcon with RCD showed no significant difference with arcon articulator (P = 0.71) while both were significantly different from nonarcon without RCD (P < 0.001). Conclusion: "The RCD" compensates the condylar guidance inclination difference between arcon and nonarcon articulators. The device precisely transfers the hinge movement of the upper member of the articulator to the condylar track. [ABSTRACT FROM AUTHOR]

Aim: Our previous three-year randomized control trial showed that the application of MI Varnish™ (5% NaF/CPP-ACP) every 3 months reduced further caries development in 6- and 12-year-olds over a 3-year period. The purpose of this secondary analysis was to investigate whether MI Varnish™ had a differential effect on cumulative caries increment on different tooth surfaces. Methods: Group 1 (n = 48) (6-year-old children) and Group 3 (n = 47) (12-year-old children) received quarterly varnish applications, while Group 2 (n = 48) (6-year-old children) and Group 4 (n = 37) (12-year-old children) did not receive varnish applications. ICDAS caries scoring classified lesions as non-cavitated (n/c) lesions (ICDAS 1 and 2), cavitated (c) lesions (ICDAS II 3–6), non-cavitated lesions around restorations (CARn/c), and cavitated lesions around restorations (CARc). Thus, 'decayed' in DFS was calculated as (ICDAS 1–6 + CARn/c + CARc). The Chi-square test, Welch test (paired-t test), risk ratio test, and Pearson correlation coefficient were used for statistical analysis (α = 0.05). Results: After comparing baseline and 36-month data, in group 1, there was a significant (p < 0.01) reduction in caries in occlusal (23.11%) and proximal (21.35%) surfaces and a non-significant reduction in buccal/lingual surfaces (5.28%). In group 2, caries reduction was significant (p < 0.01) in occlusal surfaces (38.52%) but non-significant in proximal (7.78%) and buccal/lingual (7.12%) surfaces. In groups 3 and 4, significant (p < 0.001) increases in caries were observed in proximal (36.03% (group 3)/54.30% (group 4)) and buccal/lingual surfaces (51.02% (group 3)/45.98% (group 4)), and a non-significant increase was observed in occlusal surfaces (11.49% (group 3)/22.01% (group 4)). The relative risk had increased by 4% only on proximal surfaces in 6-year-olds. Conclusions: the application of MI Varnish™ every 3 months demonstrated a caries reduction effect on interproximal and occlusal surfaces among 6- and 12-year-old children. (Trial registration ISRCTN10584414). [ABSTRACT FROM AUTHOR]

Purpose: To compare patient-reported outcomes among complete dentures with balanced, lingualized, and monoplane occlusal schemes in relation to edentulous arch classifications. Materials and Methods: This randomized controlled trial was conducted in edentulous patients receiving new complete dentures using a balanced, lingualized, or monoplane occlusal scheme. Demographic variables, residual bone ridge quantity, the number of adjustments required after denture insertion, and satisfaction and quality of life (QoL) indices (Denture Satisfaction Questionnaire [DSQ] and General Oral Health Assessment Index [GOHAI], respectively) were assessed at 1, 2, 4, 8, 12, and 52 weeks. Within-group comparisons at the different time points were carried out using Brunner-Langer nonparametric analysis. Furthermore, Kruskal-Wallis test was used to compare distributions of ordinal and continuous variables among the three occlusal scheme groups. Results: A total of 60 subjects (mean age: 68.1 ± 11.1 years; 56.7% men and 43.3% women; n = 20 per group) were analyzed. All three groups presented significant improvements in DSQ and GOHAI scores between denture insertion and the 1-year follow-up (P < .001). There were no statistical differences in the distribution of demographic variables (age, gender, years edentulous, and age of existing dentures) or of the residual bone ridge classifications among the three groups. Similarly, there were no statistical differences in ridge classifications or in the DSQ and GOHAI values between the maxilla and mandible (P > .05) within groups over the 52-week follow-up. On the other hand, the number of cases requiring denture adjustments was significantly lower in the lingualized scheme group compared to the other two groups (P = .034). Conclusion: Within the limitations of this study, the present findings suggest that the occlusal scheme for posterior teeth did not influence patient-reported outcomes. However, the lingualized occlusal scheme required significantly fewer adjustments. [ABSTRACT FROM AUTHOR]

Objectives: The objective of this study is to evaluate the longevity of two fiber post cementation strategies in a prospective, multicenter, non-inferiority, double-blind randomized controlled trial. Methods: A total of 152 teeth, with adequate endodontic treatment and loss of coronal structure and bilateral simultaneous posterior occlusal contacts, were randomly allocated to receive glass fiber posts cemented with a conventional cementation strategy (CRC group: adhesive system + resin cement) (Adper Single Bond + RelyX ARC; 3 M-ESPE) or a self-adhesive cementation strategy (SRC group: self-adhesive resin cement; RelyX U100/U200; 3 M-ESPE). The patients were recalled annually for clinical and radiographical evaluation with a 93% recall rate (142 teeth, with 74 at CR groups and 68 at SRC group). The primary outcome was survival rate, considering the fiber post debonding (loss of retention). The secondary outcome included the success rate of the prosthetic treatment with crown debonding, post fracture, and tooth loss (not related to post failure). Both outcomes were evaluated annually. The Kaplan–Meier method and Cox regression with 95% confidence interval were used for the statistical analysis. Results: For the primary outcome (failures directly related to fiber posts cementation strategy), there were 4 fiber post debondings (2 per group), 8 root fractures (3 for SRC group and 5 for CRC group), and one mixed failure (debonding combined with root fracture for CRC), with both strategies presenting similar survival rates (p = 0.331), with 88.9% for the CRC group and 90.9% for the SRC group. For the secondary outcome (failures not related to fiber post cementation strategies), there were 8 crown debondings, 3 post fractures, and 3 tooth losses, with no statistically difference between groups (p = 0.701), with 77% for SRC and 82% for CRC. Conclusion: Fiber post cementation strategies with conventional or self-adhesive resin cement presents similar tooth survival and success rates. Trial registration: NCT01461239 Clinical relevance: Both adhesive cementation strategies led to high survival and success rates and are indicated for fiber post cementation, even after a long follow-up period (up to 106 months). [ABSTRACT FROM AUTHOR]

This systematic review aimed to identify the main tools used to analyze the relationship between the postural and stomatognathic systems. The study followed the PRISMA guidelines, and data were collected from Science Direct and PubMed databases to identify articles published until December 2022. After applying inclusion and exclusion criteria, 26 articles were selected from the initial 903 articles. The selected articles were full-text studies in English or Romanian, examining the relationship between dental occlusion and posture, measuring postural parameters using various tools, implementing occlusal changes, evaluating patients with permanent dentition, or analyzing the connection between occlusion and posture in a unidirectional manner. The findings indicate that orthognathic surgery and orthodontic mouthguards can significantly enhance postural balance and athletic performance. In addition, 63% of the studies concluded that varying modifications and occlusal conditions impact posture. Notable differences exist concerning posture and Angle dental occlusion classes, and different occlusal devices used to simulate malocclusion can affect patients' postural systems in response to external stimuli. The stabilometry platform is the predominant method for measuring postural parameters; however, other researchers have employed raster stereography, photogrammetry, mobile phone apps, and the Fukuda-Unterberger test. Consequently, interventions targeting the stomatognathic system should consider potential variations in the postural system. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this self-controlled clinical study was to evaluate the trueness of occlusal contacts of chairside CAD/CAM crowns fabricated using different ceramic materials. Materials and methods: Ten volunteers (8 females, 2 males, average aged 20–30) were recruited in this study registered in the Clinical Trials Registry (#NCT05346744). After tooth preparation on tooth 36 or 46, an optical scan unit (CEREC Omnicam, Sirona Dental Systems, Germany) was utilized to perform the intraoral scanning. For each volunteer, 6 crowns were fabricated via the chairside CAD/CAM process (CEREC, Sirona Dental Systems, Germany) using the following materials: InCoris TZI (ZIR), Celtra Duo (CD), e.max CAD (EMA), UP.CAD (UP), Enamic (ENA) and Hyramic (HY). The microhardness of the milled surfaces was measured through a Vickers hardness Tester (HVS-50Z, Trojan, China). Together with the amount of occlusal adjustment, the occlusal contact trueness at both milling and postprocessing stages were quantitatively analyzed by using a high-precision scanner (ATOS, GOM Technologies, USA) and a reverse engineering software (Geomagic Control, 3D Systems, Rock Hill, SC). The times of chairside occlusal adjustment were also recorded. Data were analyzed by one-way analysis of variance (ANOVA) and ANOVA with randomized block design followed by Bonferroni test (p = 0.05). Results: Significant differences were found in surface microhardness of the materials tested (CD > EMA ~ UP > ENA > HY > ZIR, p < 0.05). Regarding the occlusal contact trueness at milling stage, ZIR showed the lowest (p < 0.05), while no significant difference was found among others (p > 0.05). At postprocessing stage, except for ENA, the occlusal contact trueness of ZIR was significantly lower than that of others (p < 0.05). As for occlusal adjustment amount, ZIR was lower than CD and ENA (p < 0.05). In addition, ENA, HY and ZIR required fewer times of occlusal adjustment than EMA, UP and CD. Conclusions: The type of chairside CAD/CAM ceramic materials affected the occlusal contact trueness throughout the process of manufacturing and the amount of clinical occlusal adjustment as well. Zirconia exhibited the worst occlusal contact trueness at both milling and postprocessing stages, while the amount of occlusal adjustment was the least, which recommended the least occlusal compensation. Clinical relevance: For better trueness, different negative occlusal offsets are suggested to be applied in the design process, so as to suit the material of the restoration. [ABSTRACT FROM AUTHOR]

Objectives: To investigate the effect of a novel interocclusal recording method on the occlusal accuracy of implant‐supported fixed prostheses for partially dentate patients with distal extension. Materials and Methods: Twenty patients with two or more adjacent teeth missing in the distal extension and scheduled to receive implant‐supported fixed prostheses were enrolled. Two interocclusal recording methods were used: placing polyvinyl siloxane (PVS) on the interocclusal recording caps (test), and placing PVS on healing abutments (control). The intraoral occlusal contacts in maximal intercuspal position (MIP) were compared with those in the mounted casts to calculate sensitivity and positive predictive value (PPV). Then, patients were randomly allocated into two groups to determine which interocclusal record would be used. The implant prostheses' evaluations mainly included occlusal adjustment height, volume, and time, occlusal contact score based on articulating paper examination. Paired‐samples t‐test, Mann–Whitney U test, and least squares regression analyzed the statistic differences. Results: The test method had higher sensitivity to detect intraoral occlusal contacts than the control method (p =.002), but similar PPV (p =.10). During the prostheses' evaluations, the occlusal adjustment height in the test group was significantly lower than that in the control group [99.4 (53.2, 134.2) vs. 159.0 (82.3, 247.8) μm, p =.03], while the occlusal contact score before adjustment was higher (p =.006). The groups had similar occlusal adjustment volume and time. Conclusions: The novel interocclusal recording method for implant‐supported fixed prostheses was more accurate and could reduce the occlusal adjustment. [ABSTRACT FROM AUTHOR]

Purpose: To compare the rest vertical dimension (RVD) and occlusal vertical dimension (OVD) measurements obtained using a facial scanner with conventional methods and to evaluate the influence of the file format on the accuracy of the digital calculations.Materials and Methods: Participants (N = 30) received marks on the glabella (Gb), tip of the nose (TN), and pogonion (Pg). Interlandmark distances Gb-TN and TN-Pg in the OVD and RVD positions were recorded by two operators conventionally (manual group) and digitally (digital group). For the manual group, measurements were obtained using a caliper. For the digital group, 10 scans in each position were obtained using a facial scanner (Face Camera Pro, Bellus3D) and exported in tessellation with polygonal faces (OBJ) and standard tessellation language (STL) file formats. Digital measurements were performed using both facial scan file formats and a software (Matera 2.4, exocad). The interocclusal rest distance (IRD) and the intraclass correlation coefficient were calculated. Shapiro-Wilk test was used to determine normal distribution. An independent samples t test, one-way analysis of variance, and post hoc Tukey test were used for analyses (± = .05).Results: No significant differences were found between the manual and digital measurements using the OBJ files or digital measurements using the STL files (P > .05). The IRD ranged from 0.72 ± 0.48 mm to 5.00 ± 1.34 mm. The inter- and intra-operator reliability were significant (P < .001), with a Cronbach's alpha value ranging from .994 to .997.Conclusion: No difference was found between manual and digital measurements. A high measurement consistency was encountered for each operator and between the operators. The facial scan file format did not influence the digital measurements. [ABSTRACT FROM AUTHOR]

Copyright of Necmettin Erbakan University Dental Journal (NEU Dent J) is the property of Necmettin Erbakan University Dental Journal (NEU Dent J) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: This in vitro study aimed to evaluate the effects of restorative materials and scanning aid conditions on the accuracy and time efficiency of intraoral scans. Materials and Methods: Identical anatomic contour crowns were fabricated using the following materials: hybrid ceramic, 3 mol% yttria‐stabilized tetragonal zirconia, 4 mol% yttria‐partially stabilized zirconia, 5 mol% yttria‐partially stabilized zirconia, cobalt–chromium (Co–Cr), resin, lithium disilicate, and feldspathic ceramic. The models were digitized and analyzed for accuracy (n = 10) under three scanning aid conditions (powder‐based, liquid‐based, and none). Additionally, the effect of metal restorations on the scan accuracy of other crowns was investigated. The scan time for complete arches was also recorded. One‐way analysis of variance, Welch analysis of variance, and post‐hoc comparison or independent t‐tests were used for trueness analysis, and the F‐test was used to examine precision (α = 0.05). Results: Significant differences were observed in the trueness of the different restorative materials under the no‐scanning aid condition (P < 0.05). In contrast, no statistically significant difference among the groups was observed with the powder‐ or liquid‐based scanning aid. For each restorative material, the no‐scanning aid condition showed significantly lower trueness than that with powder‐ or liquid‐based scanning aids. The presence of a Co–Cr crown did not affect the trueness of other restorations in the arch. The scan time efficiency significantly increased on applying a powder‐ or liquid‐based scanning aid. Conclusions: Using a scanning aid was effective to improve the scan accuracy of the tested restorative materials and scan time efficiency. Applying scanning aids to existing intraoral restorations can help improve prosthesis quality and reduce the need for clinical adjustment at the occlusal or proximal contacts. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Orofacial Orthopedics/Fortschritte der Kieferorthopadie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of West China Journal of Stomatology is the property of Sichuan University, West China College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Purpose: To evaluate and compare the clinical effectiveness of alkasite with nanofilled resin composite restorations for occlusal caries lesions in permanent molar teeth of children, at one-year follow-up. Methods: In this randomized controlled clinical trial with parallel design, 38 children aged 7–13 years with occlusal caries lesions on 59 first permanent molars were randomly allocated into two groups, Group 1: Filtek™ Z350XT (nanocomposite) and Group 2: Cention N® (alkasite resin composite). The restorations were evaluated at one year using the United States Public Health Service (USPHS) criteria. Data were analyzed using Chi-square or Fisher's exact test. Results: All restorations had either Alpha or Bravo scores at one-year follow-up. In Group 1, all restorations scored Alpha, while one restoration each (3.6%) in Group 2 scored Bravo for fracture and marginal adaptation. All restorations in both groups scored Alpha for retention, secondary caries, and post-operative sensitivity. For anatomic form, all restorations in Group 1 scored Alpha, while three (10.7%) restorations in Group 2 had Bravo scores. For marginal discolouration, three restorations in both groups scored Bravo (11.5% and 10.7%, respectively). For surface roughness, one restoration (3.8%) in Group 1 and three restorations in Group 2 (10.7%) scored Bravo. The comparative results between the two groups for all the variables in the USPHS criteria were not statistically significantly different. Conclusions: The performances of the nanofilled composite and alkasite were clinically acceptable and comparable. Alkasite can be an alternative material for the restoration of occlusal caries lesions in permanent molars of children. Clinical trial registration: The clinical trial was registered at Clinical Trials Registry—India (CTRI Reg no: CTRI/2020/12/029830 Dated: 15/12/2020). [ABSTRACT FROM AUTHOR]

Introduction: Composite resins are considered the pinnacle of esthetic restorations, but they have their own disadvantages, such as polymerization shrinkage, low fracture toughness, and the formation of microcracks, all of which eventually results in failure of the restoration. Fracture toughness is an important factor for failure. Warming the same composites to certain temperatures will show drastic improvements in the above-mentioned flaws, especially the fracture toughness. Need for the study: Therefore, the objective of this study is to evaluate and compare the fracture toughness of three different types of composite resin systems at two different pre-heating temperatures. The study aims to provide valuable information to clinicians in choosing the most appropriate restorative material for posterior composite restorations, which can ultimately improve the treatment's success rate and reduce the risk of complications such as secondary caries, postoperative sensitivity and ultimately restoration failure. Objective: In summary, this study will compare and evaluate the fracture toughness of nanohybrid, micro-hybrid, and bulk-fill composite resins pre-heated at 50 degrees Celsius and 60 degrees Celsius. Methodology: The methodology involves dividing 72 freshly extracted premolars with intact occlusal anatomy and fully developed apical foramina into three main groups based on three different composites and further dividing each group into two sub-groups based on two different pre-heating temperatures, with 12 teeth in each group. Each tooth will then be prepared with a Class-II Mesio-Occlusal-Distal (MOD) cavity and receive pre-heated composite restoration according to its assigned group and sub-group. The prepared samples will be tested for fracture toughness using a universal testing machine. [ABSTRACT FROM AUTHOR]

Background: To explore the digitisation of jaw movement trajectories through devices and discuss the physiological factors and device-dependent variables with their subsequent effects on the jaw movement analyses. Methods: Based on predefined eligibility criteria, the search was conducted following PRISMA-P 2015 guidelines on MEDLINE, EBSCO Host, Scopus, PubMed, and Web of Science databases in 2022 by 2 reviewers. Articles then underwent Cochrane GRADE approach and JBI critical appraisal for certainty of evidence and bias evaluation. Results: Thirty articles were included following eligibility screening. Both in vitro experiments (20%) and in vivo (80%) devices ranging from electronic axiography, electromyography, optoelectronic and ultrasonic, oral or extra-oral tracking, photogrammetry, sirognathography, digital pressure sensors, electrognathography, and computerised medical-image tracing were documented. 53.53% of the studies were rated below "moderate" certainty of evidence. Critical appraisal showed 80% case–control investigations failed to address confounding variables while 90% of the included non-randomised experimental studies failed to establish control reference. Conclusion: Mandibular and condylar growth, kinematic dysfunction of the neuromuscular system, shortened dental arches, previous orthodontic treatment, variations in habitual head posture, temporomandibular joint disorders, fricative phonetics, and to a limited extent parafunctional habits and unbalanced occlusal contact were identified confounding variables that shaped jaw movement trajectories but were not highly dependent on age, gender, or diet. Realistic variations in device accuracy were found between 50 and 330 µm across the digital systems with very low interrater reliability for motion tracing from photographs. Forensic and in vitro simulation devices could not accurately recreate variations in jaw motion and muscle contractions. [ABSTRACT FROM AUTHOR]

Background: A wide range of functional devices allow stimulating mandibular growth in class II patients, through mandibular advancement; managing to correct this type of skeletal and occlusal disharmony. Fixed repositioning appliances apply constant forces to the TMJ and may cause remodeling of the articular condyle and glenoid fossa. Computed tomography (CT) has been the gold standard for imaging the bone and hard tissues of the TMJ, but today cone beam computed tomography (HCCT) and Nuclear Magnetic Resonance (MRI) are used, because of their low and zero levels, respectively, of radiation. Objective: to measure morphological changes through TMJ imaging evaluation after correction of class II malocclusion with functional treatment with appliances in growing patients Methods: a comprehensive systematic literature search was conducted from January 2015 to May 2023 in the following bibliographic databases PubMed, EBSCO, Embase, and the Cochrane Library. Results: 10 studies were selected. The total sample size was 210 patients, and the age range was 10.3 to 14 years. The main imaging method used was HCCT with n = 9. Conclusions: The main change described is condylar remodeling, followed by morphological adaptation of the fossa. Although no significant differences have been reported in morphological changes in the TMJ between fixed versus removable functional appliances, fixed appliances cause a higher incidence of morphological changes. [ABSTRACT FROM AUTHOR]

Dentoskeletal changes caused by the long-term use of mandibular advancement devices (MADs) for obstructive sleep apnea (OSA) have rarely been investigated in Japan. We assessed the long-term dentofacial morphological changes in 15 Japanese patients with OSA who used two-piece MADs for an average of 4 years. Lateral cephalography analyses were performed initially and 4 years later (T1). The dental assessment included overjet, overbite, upper anterior facial height, lower anterior facial height (LAFH), total anterior facial height (TAFH), and anterior facial height ratio. Dental casts were digitized and analyzed using a 3D scanner. Changes in the apnea hypopnea index (AHI) and other sleep-assessment indices were assessed using polysomnography and out-of-center sleep testing. Radiography revealed lingual inclination of the maxillary central incisors, labial inclination of the mandibular central incisors, clockwise rotation of the mandible, and an increase in the TAFH and LAFH at T1. In the dental cast analysis, the diameter width and palatal depth tended to decrease and increase, respectively. There was a significant decrease in the AHI and other sleep assessment indices after using the MADs for approximately 4 years. However, these findings do not provide a strong basis and should be interpreted cautiously. Future studies should have a larger sample size and should further investigate the long-term occlusal and dental changes caused by the original MADs in Japanese patients with OSA. [ABSTRACT FROM AUTHOR]

Copyright of Quintessenz der Zahntechnik is the property of Quintessenz Verlags GmbH and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)