Acetabular coverage exerts minimal influence on femoral head collapse and the necessity for surgical intervention in patients with osteonecrosis of femoral head.

PURPOSE: The acetabular coverage in osteonecrosis of the femoral head (ONFH) affects the need for surgical intervention, and the collapse of the femoral head remains unclear. This study aimed to evaluate the relation between the acetabular coverage and the need for surgical treatment and femoral head collapse. METHODS: The study included 158 patients with 252 hips with glucocorticoid administration and idiopathic ONHF without osteoarthritis changes. The mean age at the first visit was 45.2 years, and the mean follow-up period was 92.2 months. All ONFH hips were subsequently divided into two groups: those needing surgical intervention and those without surgery. Additionally, it divided 167 initially non-collapsed hips into those that either later collapsed or not. Radiographic parameters with the centre-edge angle, acetabular roof obliquity, sharp angle, and necrotic location, following the guidelines of the Japanese Investigation Committee, were evaluated. RESULTS: There were no significant differences in radiographic parameters between the 106 hips that underwent surgery and the 146 hips without surgery. Among the 167 hips without initial collapse, 91 eventually collapsed while 76 did not; their radiographic findings have no significant differences. The necrotic locations were significantly larger in hips requiring surgical intervention or femoral head collapse. Furthermore, 21.8% (55 out of 252 hips) had acetabular dysplasia, which did not significantly correlate with the necessity for surgical treatment or the incidence of femoral head collapse. CONCLUSIONS: Acetabular coverage has little effect on the necessity for surgical treatment and femoral head collapse in ONFH patients over a long-term follow-up.

Long-term results of Chiari pelvic osteotomy on the preservation of hip function with mean follow-up of more than 30 years and its prognostic factors.

BACKGROUND: Clinical outcomes of Chiari pelvic osteotomy for acetabular dysplasia, including conversion to total hip arthroplasty (THA), have not been adequately explored. The purpose of this study was to examine the long-term results and clinical outcomes of Chiari pelvic osteotomy as the primary outcome and to analyze its prognostic factors as the second outcome. METHODS: This study was a multicenter, retrospective cohort study. Ninety-seven patients underwent Chiari pelvic osteotomy at three hospitals between March 1975 and October 1997. The long-term clinical outcomes of Chiari pelvic osteotomy, including conversion to THA and hip pain, were analyzed using the Kaplan-Meier method. In addition, the prognostic factors for conversion to THA after Chiari pelvic osteotomy were evaluated with clinical variables and radiographic parameters. RESULTS: The study included 51 hips in 45 patients (4 men and 41 women) with long-term follow-up. The survival rates assessed by Kaplan-Meier analysis with conversion to THA as an endpoint, were 90.2% (95% confidence interval (CI) 82.0-98.4%) at 20 years and 73.5% (95% CI 61.1-86.0%) at 30 years. In contrast, the Kaplan-Meier survival rates with the Japanese Orthopaedic Association hip score for pain ≤20 as an endpoint, were 86.3% (95% CI 76.8-95.7%) at 20 years and 65.6% (95% CI 52.3-79.0%) at 30 years. Only older age at osteotomy was the significantly poor prognostic factor for conversion to THA, with a hazard ratio of 1.11/year, 95% CI 1.06 to 1.18, (p < 0.01). CONCLUSION: Chiari pelvic osteotomy may still be a good alternative to bony reconstructive surgery for acetabular dysplasia especially in young patients. Only older age at the osteotomy was related to the poor prognosis of preserving hip function.

Three-dimensional evaluation of sleep bruxism-related splint wear using a dental laboratory scanner: A preliminary clinical study.

BACKGROUND: The wear depth on the occlusal splint (OS) is reportedly associated with the sleep bruxism (SB) level, as evaluated using portable polysomnography (PSG) recordings. However, the OS is deformed owing to SB forces, possibly preventing the accurate quantification of the wear facets. OBJECTIVES: We aimed to introduce a newly developed system to quantify the wear facets on the OS using a dental laboratory scanner (D810) and investigate the association between the wear facets, as evaluated with this system, and the SB level. METHODS: Ten healthy individuals who were diagnosed with SB based on portable PSG recordings participated in this study. They were asked to wear the OS for 2 months. The first day after a 2-week adaptation period was defined as the reference day, and sequential scanning of the OS surface was performed on days 15, 30, and 45. Changes in the OS surface from the reference day allowed dimensional evaluation of the wear facets in terms of maximum wear depth, wear area, and wear volume. Multiple regression analyses were conducted to test whether each of these variables could be predicted by any of the SB-related variables. RESULTS: The total duration of SB episodes per hour of sleep and the maximum muscle activity were significantly associated with the wear area, as measured with our system (adjusted R-squared was .78, p < .01). CONCLUSION: Our system allows dimensional analysis of the wear facets on the OS surface in association with the SB level.

Genome-Wide Association Study and Transcriptome of Japanese Patients with Developmental Dysplasia of the Hip Demonstrates an Association with the Ferroptosis Signaling Pathway.

This study examined the association between developmental dysplasia of the hip (DDH) and disease-associated loci in a Japanese cohort. A genome-wide association study (GWAS) of 238 Japanese patients with DDH and 2044 healthy individuals was performed. As a replicate, GWAS was also conducted on the UK Biobank data with 3315 cases and matched 74,038 controls. Gene set enrichment analyses (GSEAs) of both the genetics and transcriptome of DDH were performed. Transcriptome analysis of cartilage specimens from DDH-associated osteoarthritis and femoral neck fractures was performed as a control. Most of the lead variants were very low-frequency ones in the UK, and variants in the Japanese GWAS could not be replicated with the UK GWAS. We assigned DDH-related candidate variants to 42 and 81 genes from the Japanese and UK GWASs, respectively, using functional mapping and annotation. GSEA of gene ontology, disease ontology, and canonical pathways identified the most enriched pathway to be the ferroptosis signaling pathway, both in the Japanese gene set as well as the Japanese and UK merged set. Transcriptome GSEA also identified significant downregulation of genes in the ferroptosis signaling pathway. Thus, the ferroptosis signaling pathway may be associated with the pathogenic mechanism of DDH.

Oral function of implant-assisted removable partial dentures with magnetic attachments using short implants: A prospective study.

OBJECTIVES: This prospective study aimed to compare the oral functions of removable partial dentures (RPDs) with those of implant-assisted removable partial dentures (IARPDs) with short implants and magnetic attachments in patients with mandibular Kennedy class I and II. MATERIAL AND METHODS: Thirty participants with mandibular Kennedy class I or II and at least three distal missing teeth were recruited. Oral functions, including mixing ability, comminuting ability, maximum bite force, and occlusal contact area, were assessed for RPDs (stage 0), IARPDs with healing caps (stage 1), and IARPDs with magnetic attachments (stage 2). The implants were loaded with occlusal force in stages 1 and 2. Finally, the data of the 27 participants who completed the evaluation at stage 2 were analyzed. The Wilcoxon signed-rank test with Bonferroni correction was used to assess the differences in the oral functions among the different stages. RESULTS: The implant survival rate was 93.8%. There were significant differences in the comminuting ability and occlusal contact area between stages 0 and 2 (p < .001 and p = .036, respectively) and stages 1 and 2 (p = .003 and p = .015, respectively). Regarding the maximum bite force, there was a significant difference between stages 1 and 2 (p = .018). However, there was no significant difference in the mixing ability between the three stages. CONCLUSIONS: Within the limitations of this study, it was concluded that IARPDs in the mandible with short implants and magnetic attachments may improve oral functions.

Effects of vibratory feedback stimuli through an oral appliance on sleep bruxism: a 6-week intervention trial.

PURPOSE: Various biofeedback stimulation techniques of managing sleep bruxism (SB) have recently emerged; however, the effect of successive application of vibratory feedback stimulation has not been clarified. This study elucidated the effect of vibration feedback stimulation via an oral appliance (OA) on SB when vibration feedback was applied for 4 weeks. METHODS: This was a prospective, single-arm, open-label, intervention study. Ten participants diagnosed with "definite" SB wore a specially designed OA for 45 nights in a home-setting. A force-based SB detection system, including a pressure-sensitive piezoelectric film placed internally in the OA, triggered a vibrator attached to the OA. Vibratory stimulation was withheld during the first 2-week adaptation period (1st-15th nights), applied during the 4-week stimulation period (16th-43rd nights), and again withheld during the post-stimulation period (44th and 45th nights). The number and duration of SB episodes/hour of sleep were calculated based on masseter electromyographic activity recorded with in-home portable polysomnography and compared between the 15th and 45th nights (without stimulation) and the 17th and 43rd nights (with stimulation). RESULTS: The number and duration of SB episodes significantly decreased after vibratory stimulation (15th vs. 17th nights: p = 0.012 and p = 0.012, respectively), then significantly increased upon cessation of vibratory stimulation after the stimulation period (43rd vs. 45th nights: p = 0.023 and p = 0.023, respectively). CONCLUSION: Contingent vibratory stimulation through an OA may suppress SB-related masticatory muscle activity continuously for 4 weeks and may be an effective alternative for the management of SB. TRIAL REGISTRATION: https://jrct.niph.go.jp/ ; trial registration number: jRCTs032190225.

Octacalcium Phosphate/Gelatin Composite (OCP/Gel) Enhances Bone Repair in a Critical-sized Transcortical Femoral Defect Rat Model.

BACKGROUND: Bone grafting is widely used to treat large bone defects. A porous composite of a bioactive octacalcium phosphate material with gelatin sponge (OCP/Gel) has been shown to biodegrade promptly and be replaced with new bone both in animal models of a membranous bone defect and a long bone defect. However, it is unclear whether OCP/Gel can regenerate bone in more severe bone defects, such as a critical-size transcortical defect. QUESTIONS/PURPOSES: Using an in vivo rat femur model of a standardized, transcortical, critical-size bone defect, we asked: Compared with a Gel control, does OCP/Gel result in more newly formed bone as determined by (1) micro-CT evaluation, (2) histologic and histomorphometric measures, and (3) osteocalcin staining and tartrate-resistant acid phosphatase staining? METHODS: Thirty-four 12-week-old male Sprague-Dawley rats (weight 356 ± 25.6 g) were used. Gel and OCP/Gel composites were prepared in our laboratory. Porous cylinders 3 mm in diameter and 4 mm in height were manufactured from both materials. The OCP/Gel and Gel cylinders were implanted into a 3-mm-diameter transcortical critical-size bone defect model in the left rat femur. The OCP/Gel and Gel were randomly assigned, and the cylinders were implanted. The biological responses of the defect regions were evaluated radiologically and histologically. At 4 and 8 weeks after implantation, CT evaluation, histological examination of decalcified samples, and immunostaining were quantitatively performed to evaluate new bone formation and remaining bone graft substitutes and activity of osteoblasts and osteoclast-like cells (n = 24). Qualitative histological evaluation was performed on undecalcified samples at 3 weeks postimplantation (n = 10). CT and decalcified tissue analysis was not performed blinded, but an analysis of undecalcified specimens was performed under blinded conditions. RESULTS: Radiologic analysis revealed that the OCP/Gel group showed radiopaque regions around the OCP granules and at the edge of the defect margin 4 weeks after implantation, suggesting that new bone formation occurred in two ways. In contrast, the rat femurs in the Gel group had a limited radiopaque zone at the edge of the defect region. The amount of new bone volume analyzed by micro-CT was higher in the OCP/Gel group than in the Gel group at 4 and 8 weeks after implantation (​​4 weeks after implantation: OCP/Gel versus Gel: 6.1 ± 1.6 mm 3 versus 3.4 ± 0.7 mm 3 , mean difference 2.7 [95% confidence interval (CI) 0.9 to 4.5]; p = 0.002; intraclass correlation coefficient [ICC] 0.72 [95% CI 0.29 to 0.91]; 8 weeks after implantation: OCP/Gel versus Gel: 3.9 ± 0.7 mm 3 versus 1.4 ± 1.1 mm 3 , mean difference 2.5 [95% CI 0.8 to 4.3]; p = 0.004; ICC 0.81 [95% CI 0.47 to 0.94]). Histologic evaluation also showed there was a higher percentage of new bone formation in the OCP/Gel group at 4 and 8 weeks after implantation (​​4 weeks after implantation: OCP/Gel versus Gel: 31.2% ± 5.3% versus 13.6% ± 4.0%, mean difference 17.6% [95% CI 14.2% to 29.2%]; p < 0.001; ICC 0.83 [95% CI 0.53 to 0.95]; 8 weeks after implantation: OCP/Gel versus Gel: 28.3% ± 6.2% versus 9.5% ± 1.9%, mean difference 18.8% [95% CI 11.3% to 26.3%]; p < 0.001; ICC 0.90 [95% CI 0.69 to 0.97]). Bridging of the defect area started earlier in the OCP/Gel group than in the Gel group at 4 weeks after implantation. Osteocalcin immunostaining showed that the number of mature osteoblasts was higher in the OCP/Gel group than in the Gel group at 4 weeks (OCP/Gel versus Gel: 42.1 ± 6.5/mm 2 versus 17.4 ± 5.4/mm 2 , mean difference 24.7 [95% CI 16.2 to 33.2]; p < 0.001; ICC 0.99 [95% CI 0.97 to 0.99]). At 4 weeks, the number of osteoclast-like cells was higher in the OCP/Gel composite group than in the Gel group (OCP/Gel versus Gel: 3.2 ± 0.6/mm 2 versus 0.9 ± 0.4/mm 2 , mean difference 2.3 [95% CI 1.3 to 3.5]; p < 0.001; ICC 0.79 [95% CI 0.35 to 0.94]). CONCLUSION: OCP/Gel composites induced early bone remodeling and cortical bone repair in less time than did the Gel control in a rat critical-size, transcortical femoral defect, suggesting that OCP/Gel could be used as a bone replacement material to treat severe bone defects. CLINICAL RELEVANCE: In a transcortical bone defect model of critical size in the rat femur, the OCP/Gel composite demonstrated successful bone regeneration. Several future studies are needed to evaluate the clinical application of this interesting bone graft substitute, including bone formation capacity in refractory fracture and spinal fusion models and the comparison of bone strength after repair with OCP/Gel composite to that of autologous bone.

Clinical evaluation of the precision of interocclusal registration by using digital and conventional techniques.

STATEMENT OF PROBLEM: Although studies have evaluated the accuracy of data obtained by intraoral scanners (IOSs), studies on the precision of interocclusal registrations made with IOSs are lacking. PURPOSE: The purpose of this clinical study was to compare the precision of IOS interocclusal registration with that of conventional methods with a silicone impression material and a gypsum cast. MATERIAL AND METHODS: Eight participants with complete natural dentitions were enrolled. Images of their maxillary and mandibular quadrant arches and their interocclusal relationship were scanned with 2 IOSs: the 3M True Definition Scanner and the TRIOS Scanner 3. In the conventional method, impressions of complete-arch dentition and quadrant-arch dentition were made with a silicone impression material, and gypsum casts were fabricated, mounted on a dental articulator related with a silicone interocclusal record, and scanned with a 3D laboratory scanner. These procedures were repeated 4 times, and 4 sets of interocclusal registration data in standard tessellation language (STL) format were generated for each condition. Interocclusal registration precision was evaluated by determining the discrepancy of the STL data between repeated measurements by using the best-fit-algorithm method. RESULTS: The average discrepancies for all participants were 25 ±12 µm for the True Definition, 31 ±7 µm for the TRIOS 3, 154 ±59 µm for the complete arch, and 128 ±33 µm for the quadrant arch. The Kruskal-Wallis test revealed that the effect of the impression methods on the discrepancy was statistically significant (P<.001). The Steel-Dwass test showed that both digital scan methods exhibited significantly smaller discrepancies than the 2 conventional methods (P=.005). CONCLUSIONS: These results suggest that the intermaxillary relationship captured by the digital scan method by using IOSs had better precision than that obtained by the conventional method.

Shear bond strength of an acrylic resin to a ceria-stabilized zirconia-alumina nanocomposite.

STATEMENT OF PROBLEM: Ceria-stabilized zirconia-alumina nanocomposite (Ce-TZP-Al2O3) has properties that may be suitable for partial denture frameworks. However, studies on its adhesion strength and durability with denture base resin are lacking. PURPOSE: The purpose of this in vitro study was to determine the optimal surface treatment for Ce-TZP-Al2O3 to secure a durable bond with an acrylic resin. MATERIAL AND METHODS: The surface of Ce-TZP-Al2O3 test specimens was alumina airborne-particle abraded (Group APA) and then treated with 10-methacryloyloxydecyl dihydrogen phosphate (MDP) (Group MDP) and 2 silica coating methods: the flame spraying method (Group SLP) and the tribochemical treatment (110 µm: Group TRB-P, 30 µm: Group TRB-S). TRB-P and TBR-S were further treated by MDP (Group CBT-P and CBT-S). Autopolymerizing acrylic resin was bonded to the specimens, and the shear bond strength was tested after thermocycling (5 °C and 60 °C, 10 000 cycles). The area of the resin remaining on the fractured surfaces was also measured. To evaluate the effect of the surface treatment condition on shear bond strength and the resin remaining, 1-way analysis of variance (ANOVA) was conducted, followed by the Tukey multiple comparison post hoc test. Additionally, the effect of thermocycling on the specimens was evaluated by the Student t test. RESULTS: After placement in deionized water for 24 hours, the shear bond strengths of Group MDP and 2 types of combination treatment (Groups CBT-P and CBT-S) were significantly higher than those of Groups SLP, TRB-P, and TRB-S (P<.05). Moreover, the fractured surface of all the treatment conditions except Group APA showed cohesive failure. The shear bond strength as a result of all treatment conditions decreased significantly after thermocycling (P<.05). Group CBT-S showed the highest shear bond strength; however, no significant differences were found between Groups CBT-S and MDP (P=.908). In particular, the area of resin remaining on the fractured surfaces of Group CBT-S was 100% (cohesive failure). CONCLUSIONS: The combined surface treatment of alumina airborne-particle abrasion and tribochemical treatment, along with primer treatment using silane coupling and an MDP monomer, improved the adhesion strength and adhesion durability between base resins and Ce-TZP-Al2O3.

Research routes on improved sleep bruxism metrics: Toward a standardised approach.

A recent report from the European Sleep Research Society's task force "Beyond AHI" discussed an issue that has been a long-term subject of debate - what are the best metrics for obstructive sleep apnoea (OSA) diagnosis and treatment outcome assessments? In a similar way, sleep bruxism (SB) metrics have also been a recurrent issue for >30 years and there is still uncertainty in dentistry regarding their optimisation and clinical relevance. SB can occur alone or with comorbidities such as OSA, gastroesophageal reflux disorder, insomnia, headache, orofacial pain, periodic limb movement, rapid eye movement behaviour disorder, and sleep epilepsy. Classically, the diagnosis of SB is based on the patient's dental and medical history and clinical manifestations; electromyography is used in research and for complex cases. The emergence of new technologies, such as sensors and artificial intelligence, has opened new opportunities. The main objective of the present review is to stimulate the creation of a collaborative taskforce on SB metrics. Several examples are available in sleep medicine. The development of more homogenised metrics could improve the accuracy and refinement of SB assessment, while moving forward toward a personalised approach. It is time to develop SB metrics that are relevant to clinical outcomes and benefit patients who suffer from one or more possible negative consequences of SB.

Pediatric patients' reasons for visiting dentists in all WHO regions.

BACKGROUND: Oral Function, Orofacial Pain, Orofacial Appearance, and Psychosocial Impact are the four oral health-related quality of life (OHRQoL) dimensions (4D) or areas in which oral disorders impact pediatric patients. Using their dentists' assessment, the study aimed to evaluate whether pediatric dental patients' oral health concerns fit into the 4D of the Oral Health-Related Quality of Life (OHRQoL) construct. METHODS: Dentists who treat children from 32 countries and all WHO regions were selected from a web-based survey of 1580 international dentists. Dentists were asked if their pediatric patients with current or future oral health concerns fit into the 4D of the Oral Health-Related Quality of Life (OHRQoL) construct. Proportions of all pediatric patients' oral health problems and prevention needs were computed. FINDINGS: Data from 101 dentists treating children only and 523 dentists treating children and adults were included. For 90% of pediatric patients, their current oral health problems fit well in the four OHRQoL dimensions. For 91% of oral health problems they intended to prevent in the future were related to these dimensions as well. Both numbers increased to at least 96% when experts analyzed dentists´ explanations of why some oral health problems would not fit these four categories. CONCLUSIONS: The study revealed the four fundamental components of dental patients, i.e., the four OHRQoL dimensions (Oral Function, Orofacial Pain, Orofacial Appearance, and Psychosocial Impact) are also applicable for pediatric patients, regardless of whether they have current or future oral health concerns, and should be considered when measuring OHRQoL in the pediatric dental patient population.

Mid-term results of a new femoral prosthesis using Ti-Nb-Sn alloy with low Young's modulus.

BACKGROUND: This study was performed to investigate the mid-term results of Ti-Nb-Sn (TNS) alloy stem with a low Young's modulus. METHODS: This study was a multicenter prospective cohort study. A total of 40 primary total hip arthroplasties performed between April 2016 and September 2017 was enrolled in this study. With the unique functional gradient properties by heating treatment, the strength of the proximal portion was enhanced, while the distal portion maintained a low Young's modulus. The surgeries were performed through the posterolateral approach using the TNS alloy stems. Radiographs were taken from immediately after surgeries until 3 years, and stress shielding and subsidence of the stems were evaluated. The incidences of the stem breakage were also assessed. Clinical assessments were performed using Japanese Orthopaedic Association (JOA) and Japanese Orthopaedic Association Hip Disease Evaluation Questionnaire (JHEQ) scores. RESULTS: Among the 40 enrolled patients, 36 patients were female and 4 were male. At 3 years after surgery, there were no radiologic signs of loosening, subsidence, or breakage of the stem. Stress shielding was observed in 26 hips (65%). Of 26 hips, 16 hips (40%) were grade 1 and 10 hips (25%) were grade 2. There was no advanced stress shielding. The JOA and JHEQ scores significantly improved compared with the preoperative scores. CONCLUSION: The current study using a new TNS alloy femoral stem showed good clinical outcomes at 3-year follow-up. Radiologically, there was no loosening or subsidence of the stem. The mild stress shielding was observed in 65% of patients. TRIAL REGISTRATION: Current Controlled Trials ISRCTN21241251 . The date of registration was October 26, 2021. Retrospectively registered.

Effect of eldecalcitol on muscle function and fall prevention in Japanese postmenopausal women: A randomized controlled trial.

BACKGROUD: Exercises and vitamin D interventions have shown to improve muscle function and balance, and prevent falls in postmenopausal healthy women and in patients with osteoporosis. However, the effects of eldecalcitol on these factors remain undetermined. The present open-label, randomized, controlled study aimed to investigate the effects of eldecalcitol treatment in reducing falls in postmenopausal women, and improving muscle function and balance. METHODS: The study population included 226 Japanese postmenopausal women with osteoporosis. Patients were randomly divided into two groups on the basis of treatment with or without eldecalcitol (0.75 µg/day). Treatment continued for 6 months. Participants in both groups were instructed to perform back extensor muscle exercise. Isometric back extensor and leg extensor strength, grip power, ten-meter walking speed, timed up and go test and time of single leg standing were measured at baseline and 24 weeks. Patients were asked to record the number of falls during the 24-week period. RESULTS: The percentage increase in average bilateral quadriceps muscle strength was significantly higher in the eldecalcitol group compared with the non-eldecalcitol group (right, p = 0.041; left, p = 0.042). In contrast, there were no significant differences in the strength of back muscles and grip power and the parameters of balance and walking abilities between the groups. There was no significant difference in the number of falls between the groups. CONCLUSIONS: A 24-week intervention of eldecalcitol improves the strength of the quadriceps muscles in postmenopausal women with osteoporosis. However, eldecalcitol neither improve balance and walking abilities nor reduce the number of falls.

Functional oral health-related quality of life impact: A systematic review in populations with tooth loss.

Patients perceive the impact of oral disorder in four major areas, the dimensions of oral health-related quality life (OHRQoL) Oral Function, Orofacial Pain, Orofacial Appearance, and Psychosocial Impact. The functional aspect is essential given the need of chewing, biting, speech and swallowing. The objective of this study was to identify OHRQoL information for dental subjects with functional oral health problems. In a systematic review, distinct and clinically relevant groups of dental subject samples, in this study called "population groups," with such functional OHRQoL information based on the Oral Health Impact Profile (OHIP) were identified (PROSPERO registration: CRD42017064033). The search strategy was "Oral Health Impact Profile" or OHIP. Searches were conducted in the PubMed interface of the Medline database, EMBASE, Cochrane, CINAHL and PsyINFO on 8 June 2017 and updated on 14 January 2019. Published OHIP domain data of different versions were recalculated into OHIP-14`s Physical Disability domain score, characterising the subject's Oral Function impact. 3,653 potentially abstracts were screened. We identified 78 publications reporting dimensional information on 154 subject samples with 52 populations. A typical mean functional impact for partially dentate subjects was 1.6 units on a 0 to 8 unit metric, while for edentate subjects, the mean functional impact was 2.6 units. The functional impact score ranged from 0 to 7.9 units with 50% of the patient samples located between 0.8 and 2.6 units. For the first time, we provide normalised and therefore comparable metric information about the functional OHRQoL impact for a substantial number of functional oral conditions.

Effect of contingent vibratory stimulus via an oral appliance on sleep bruxism after the splint adaptation period.

BACKGROUND: Contingent vibratory feedback stimuli applied by a specially designed oral appliance (OA) have been reported to be effective in reducing sleep bruxism (SB). However, the inhibitory effects of the OA, which occur immediately after OA delivery, may have confounded this finding. OBJECTIVE: This study sought to shed light on the effects of vibratory stimuli on SB after the OA adaptation period, when its inhibitory effects are diminished. METHODS: Fourteen 'definite' SB patients were enrolled. A force-based bruxism detection system was utilised to trigger a vibrator attached to the OA. Masseter electromyographic activity during sleep was recorded at home using portable polysomnography. After using the OA without vibratory stimulus for 16 nights (adaptation period), intermittent vibratory stimuli were applied every other half-hour for four nights (intervention period). Electromyographic activity over 10% of the maximum voluntary contraction was regarded as a SB episode. The number and the total duration of SB episodes per hour of sleep were calculated for the sessions with and without stimuli separately and averaged for four intervention nights. The effects of stimuli on these two variables were evaluated. RESULTS: The number and the total duration of the sessions without stimuli were 5.2 episodes/h and 35.3 s/h, respectively. These values significantly decreased to 3.9 episodes/h and 15.1 s/h (p < .05) for the sessions with vibratory stimuli. CONCLUSION: Contingent vibratory stimulus via an OA may be effective for the management of SB even after adaptation to OA.

Signal acquisition and analysis of ambulatory electromyographic recordings for the assessment of sleep bruxism: A scoping review.

BACKGROUND: Ambulatory electromyographic (EMG) devices are increasingly being used in sleep bruxism studies. EMG signal acquisition, analysis and scoring methods vary between studies. This may impact comparability of studies and the assessment of sleep bruxism in patients. OBJECTIVES: (a) To provide an overview of EMG signal acquisition and analysis methods of recordings from limited-channel ambulatory EMG devices for the assessment of sleep bruxism; and (b) to provide an overview of outcome measures used in sleep bruxism literature utilising such devices. METHOD: A scoping review of the literature was performed. Online databases PubMed and Semantics Scholar were searched for studies published in English until 7 October 2020. Data on five categories were extracted: recording hardware, recording logistics, signal acquisition, signal analysis and sleep bruxism outcomes. RESULTS: Seventy-eight studies were included, published between 1977 and 2020. Recording hardware was generally well described. Reports of participant instructions in device handling and of dealing with failed recordings were often lacking. Basic elements of signal acquisition, for example amplifications factors, impedance and bandpass settings, and signal analysis, for example rectification, signal processing and additional filtering, were underreported. Extensive variability was found for thresholds used to characterise sleep bruxism events. Sleep bruxism outcomes varied, but typically represented frequency, duration and/or intensity of masticatory muscle activity (MMA). CONCLUSION: Adequate and standardised reporting of recording procedures is highly recommended. In future studies utilising ambulatory EMG devices, the focus may need to shift from the concept of scoring sleep bruxism events to that of scoring the whole spectrum of MMA.

Mapping Oral Disease Impact with a Common Metric (MOM)-Project summary and recommendations.

Oral Function, Orofacial Pain, Orofacial Appearance, and Psychosocial Impact-the dimensions of oral health-related quality of life-capture dental patients' oral health problems worldwide and regardless of whether the patient currently suffers from oral diseases or intends to prevent them in the future. Using scores for these dimensions, the project Mapping Oral Disease Impact with a Common Metric (MOM) aims to provide four-dimensional oral health impact information across oral diseases and settings. In this article, project authors summarize MOM's findings and provide recommendations about how to improve standardized oral health impact assessment. Project MOM's systematic reviews identified four-dimensional impact information for 189 adult and 22 pediatric patient populations that were contained in 170 publications. A typical functional, pain-related, aesthetical, and psychosocial impact (on a 0-8 impact metric based on two items with a response format 0 = never, 1 = hardly ever, 2 = occasionally, 3 = fairly often, 4 = very often) was about 2 to 3 units. Project MOM provides five recommendations to improve standardized oral health impact assessment for all oral diseases in all settings.

Bone Tissue Response to Different Grown Crystal Batches of Octacalcium Phosphate in Rat Long Bone Intramedullary Canal Area.

The microstructure of biomaterials influences the cellular and biological responses in the bone. Octacalcium phosphate (OCP) exhibits higher biodegradability and osteoconductivity than hydroxyapatite (HA) during the conversion process from OCP to HA. However, the effect of the microstructure of OCP crystals on long tubular bones has not been clarified. In this study, two types of OCPs with different microstructures, fine-OCP (F-OCP) and coarse-OCP (C-OCP), were implanted in rat tibia for 4 weeks. F-OCP promoted cortical bone regeneration compared with C-OCP. The osteoclasts appearance was significantly higher in the C-OCP group than in the control group (defect only) at 1-week post-implantation. To investigate whether the solubility equilibrium depends on the different particle sizes of OCPs, Nano-OCP, which consisted of nanometer-sized OCPs, was prepared. The degree of supersaturation (DS) tended to decrease modestly in the order of C-OCP, F-OCP, and Nano-OCP with respect to HA and OCP in Tris-HCl buffer. F-OCP showed a higher phosphate ion concentration and lower calcium ion concentration after immersion in the buffer than C-OCP. The crystal structures of both OCPs tended to be converted to HA by rat abdominal implantation. These results suggest that differences in the microstructure of OCPs may affect osteoclastogenesis and result in osteoconductivity of this material in long tubular bone by altering dissolution behavior.

Effects of different types of intraoral scanners and scanning ranges on the precision of digital implant impressions in edentulous maxilla: An in vitro study.

OBJECTIVE: This study aimed to evaluate the precision of digital implant impressions in comparison with conventional impressions and assess the impact of the scanning range on precision. MATERIALS AND METHODS: An edentulous maxilla model with six implants was scanned with four intraoral scanners (IOSs) and a dental laboratory scanner five times each, and stereolithography (STL) data were generated. A conventional silicone impression was made, and a model was fabricated, which was scanned using the laboratory scanner. This procedure was also repeated five times. Nine different ranges of interest (ROIs) were defined, and the average discrepancies of the measurement points between each pair of STL images out of five for each ROI were calculated. The effects of "impression method" and "ROI" on precision, as evaluated by the averaged discrepancy, were tested by two-way analysis of variance (p < .05). RESULTS: The effects of "impression methods" and "ROI" and their interactions were statistically significant. The discrepancies in the scanned datasets of the dental laboratory scanner were significantly lower than those in the other impression methods. The discrepancies of the IOSs were comparable with those of the laboratory scanner when the ROI was limited, however; the discrepancies deteriorated when the ROI expanded across the arch, while those of the laboratory scanner remained stable irrespective of the ROI. CONCLUSIONS: Within the limitation of this in vitro study, digital implant impressions by IOSs may show clinically acceptable precision when the scan range is limited, such as in 3-unit superstructure supported by two implants.

Efficacy of an email-based recording and reminding system for limiting daytime non-functional tooth contact in patients with temporomandibular disorders: A randomized controlled trial.

BACKGROUND: Oral parafunctional activities such as daytime non-functional tooth contact (nFTC) are considered aetiological factors for temporomandibular disorders (TMD). OBJECTIVES: To evaluate the effectiveness of an email-based recording and reminding system for limiting daytime nFTC in patients with TMDs. METHODS: Thirty patients with TMDs (mean age, 30.7 ± 8.7 years) were randomly assigned to three groups according to the intervention for limiting nFTC: cognitive behavioural therapy (CBT) with an email-based recording and reminding system for 20 days (e-CBT group, n = 10), CBT with a sticky note reminder for 20 days (s-CBT group, n = 10) and simple verbal instructions to avoid nFTC that were provided before the experimental period (control group, n = 10). The frequency of nFTC, range of pain-free unassisted mouth opening and pain intensity during painful unassisted maximum mouth opening was evaluated before and after the experimental period. RESULTS: The frequency of nFTC significantly decreased after the intervention in the e-CBT and s-CBT groups. Among the three groups, the decrease in the nFTC frequency was the maximum in the e-CBT group (P < .01). In addition, the range of pain-free unassisted mouth opening showed a significant increase in all three groups, with the maximum improvement in the e-CBT group (analysis of variance, P < .01). CONCLUSIONS: The present findings suggest that our email-based recording and reminding system may have the potential to effectively control daytime nFTC and could be an effective strategy for the management of TMDs.