Effectiveness of zygomatic-implant fixed rehabilitation for the atrophic edentulous maxilla: protocol for a systematic review and network meta-analysis.

BACKGROUND: Atrophic edentulous maxilla is a debilitating condition caused by the progressive and irreversible bone resorption following loss of teeth, that results in bone of inadequate volume and density. This makes conventional implant therapy extremely challenging without complex reconstructive procedures. Several techniques such as sinus augmentation, short implants, and tilted implants have been used for the rehabilitation of the atrophic maxilla. In recent years, zygomatic implants have emerged as a graftless rehabilitation technique. However, few studies compare zygomatic-implant fixed rehabilitation with other fixed rehabilitation techniques. The existing body of evidence on zygomatic implants is largely based on clinical and disease-oriented outcomes. METHODS: A network meta-analysis (NMA) will be conducted in order to compare the effectiveness of zygomatic-implant fixed rehabilitation with the other rehabilitation techniques. Experimental and observational studies comparing different implant-assisted fixed rehabilitation in adults with atrophic maxilla will be included. The primary and secondary outcomes will be patient's satisfaction and quality of life respectively. Additional outcomes include the implant's survival/success, and biological and prosthetic complications. An electronic search will be performed through various databases for articles in English and French, without time limits. Risk of bias will be assessed using the Revised Cochrane Risk-of-Bias tool for randomized controlled trials, and ROBINS-I for non-randomized and observational studies. Two independent reviewers will screen the titles and abstracts and extract data. Any discrepancy between reviewers will be discussed and resolved through consensus or with the help of a third reviewer. Pairwise meta-analyses will be performed using a random effects model. I2, τ2, transitivity, subgroup/meta-regression analyses will assess and explain heterogeneity and distribution of effect modifiers. A network plot will be created to connect the different interventions directly and indirectly. Interventions will be ranked using the surface under cumulative ranking curve. Confidence in the results of the NMA will be assessed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE). DISCUSSION: This study will be the first to assess the effectiveness of zygomatic-implant fixed rehabilitation for the atrophic maxilla using NMA. The evidence obtained will aid clinical decision-making and will advance the knowledge of the rehabilitation techniques for the atrophic maxilla. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42023353303.

Prevalence, Severity, and Description of Dental Anomalies in Children Treated for Acute Lymphoblastic Leukemia.

Purpose: To assess the prevalence and severity of and describe dental anomalies in children treated for acute lymphoblastic leukemia (ALL) under recent Dana-Farber Cancer Institute (DFCI) protocols. Methods: Patients aged between 14 and 25 years old having received a diag- nosis of ALL before the age of 11 years and after September 2000 received clinical and radiographic oral examinations. Results: Dental anomalies were observed in 26 (51.0 percent) of 51 subjects. Microdontia was the most prevalent dental defect (39.2 percent). Impacted permanent second molars were observed in five (9.8 percent) patients. Being age five years or younger at diagnosis significantly increased the prevalence and severity of dental anomalies (P<0.001). Conclusions: Recent DFCI protocols showed a decreased prevalence of dental disturbances. The anomalies observed may still alter the development of the dental arches and occlusion in pediatric ALL survivors. Further research is needed to confirm the association between ALL treatment and permanent second molar impaction.

Dorsal raphe stimulation relays a reward signal to the ventral tegmental area via GluN2C NMDA receptors.

BACKGROUND: Glutamate relays a reward signal from the dorsal raphe (DR) to the ventral tegmental area (VTA). However, the role of the different subtypes of N-methyl-D-aspartate (NMDA) receptors is complex and not clearly understood. Therefore, we measured NMDA receptors subunits expression in limbic brain areas. In addition, we studied the effects of VTA down-regulation of GluN2C NMDA receptor on the reward signal that arises from DR electrical stimulation. METHODS: Using qPCR, we identified the relative composition of the different Grin2a-d subunits of the NMDA receptors in several brain areas. Then, we used fluorescent in situ hybridization (FISH) to evaluate the colocalization of Grin2c and tyrosine hydroxylase (TH) mRNA in VTA neurons. To assess the role of GluN2C in brain stimulation reward, we downregulated this receptor using small interfering RNA (siRNA) in rats self-stimulating for electrical pulses delivered to the DR. To delineate further the specific role of GluN2C in relaying the reward signal, we pharmacologically altered the function of VTA NMDA receptors by bilaterally microinjecting the NMDA receptor antagonist PPPA. RESULTS: We identified GluN2C as the most abundant subunit of the NMDA receptor expressed in the VTA. FISH revealed that about 50% of TH-positive neurons colocalize with Grin2c transcript. siRNA manipulation produced a selective down-regulation of the GluN2C protein subunit and a significant reduction in brain stimulation reward. Interestingly, PPPA enhanced brain stimulation reward, but only in rats that received the nonactive RNA sequence. CONCLUSION: The present results suggest that VTA glutamate neurotransmission relays a reward signal initiated by DR stimulation by acting on GluN2C NMDA receptors.

Adherence and efficacy of mandibular advancement splint treatment of sleep-disordered breathing during pregnancy: a pilot study.

PURPOSE: Sleep-disordered breathing (SDB) is common in pregnancy and is associated with adverse health consequences for both mother and child. Mandibular advancement splints (MAS) have been shown to improve sleep quality, daytime sleepiness and snoring in non-pregnant women. The effectiveness of MAS for treating SDB in pregnancy is unknown. This pilot study aimed to evaluate the efficacy and adherence to MAS in pregnant women with SDB. METHODS: Women with mild-moderate SDB (apnea-hypopnea index (AHI) 10-29/h) on level 2 polysomnography (PSG) performed at 22.0 ± 5.5 weeks' gestation were treated with a MAS during pregnancy to 6 months postpartum. An embedded micro-recorder measured adherence. PSG was repeated while on titrated treatment, and off treatment in the postpartum period. RESULTS: Among 17 women completing the study, MAS was worn ≥ 4 h/night for 57.5 ± 36.7% of nights during the antepartum period. While using MAS, nightly snoring time decreased from 25.9 ± 24.5% at baseline to 6.4 ± 7.8% when treated during pregnancy (p = .003). AHI decreased from 17.6 ± 5.1 to 12.9 ± 6.3 (p = .02) and fell by ≥ 30% and below 15/h in 60% of participants. During the postpartum period, MAS was used for ≥ 4 h/night on 24.8 ± 27.9% of nights. Moreover, the mean AHI off MAS was 17.9 ± 13.1; 88% of women had persistent SDB (AHI ≥ 10). CONCLUSIONS: In this cohort, treatment efficacy and objective adherence were variable. Device use was less frequent in the postpartum period even though a substantial number of women had persistent SDB after delivery. Clinical trial registered with  www. CLINICALTRIALS: gov number: NCT03138291.

Optogenetic activation of basolateral amygdala-to-nucleus accumbens core neurons promotes Pavlovian approach responses but not instrumental pursuit of reward cues.

Reward-associated conditioned stimuli (CSs) can acquire predictive value, evoking conditioned approach behaviours that prepare animals to engage with forthcoming rewards. Such CSs can also acquire conditioned reinforcing value, becoming attractive and pursued. Through their conditioned effects, CSs can promote adaptive (e.g., locating food) but also maladaptive behaviours (e.g., drug use). Basolateral amygdala neurons projecting to the nucleus accumbens core (BLA→NAc core neurons) mediate the response to appetitive CSs, but the extent to which this involves effects on the predictive and/or conditioned reinforcing properties of CSs is unclear. Thus, we examined the effects of optogenetic stimulation of BLA→NAc core neurons on i) CS-triggered approach to the site of reward delivery, a Pavlovian conditioned approach response and ii) the instrumental pursuit of a CS, a measure of conditioned reinforcement. Water-restricted, adult male rats learned that a light-tone compound cue (the CS) predicts water delivery into a receptacle. Pairing optogenetic stimulation of BLA→NAc core neurons with CS presentation potentiated CS-triggered water receptacle visits. This suggests that activity in BLA→NAc core neurons promotes Pavlovian goal-approach behaviour. Next, rats could lever press for CS presentations, without water delivery. Optogenetic stimulation of BLA→NAc core neurons either during instrumental test sessions or during prior CS-water conditioning did not influence lever responding for the CS. This suggests that activity in BLA→NAc core neurons does not influence the instrumental pursuit of a water-paired CS. We conclude that activation of BLA→NAc core neurons promotes cue-induced control over behaviour by increasing conditioned goal-approach responses, without affecting the operant pursuit of reward cues.

The influence of age on the frequency of rhythmic masticatory muscle activity during sleep in general population differs from that in clinical research samples.

BACKGROUND: During sleep, limb and jaw muscle motor activity can be quantified by electromyography (EMG). The frequency of periodic limb activity during sleep increases with age in both the general and clinical research populations. The literature is controversial regarding stability, over age, of the frequency of rhythmic masticatory muscle activity (RMMA), which is one biomarker of sleep bruxism (SB). OBJECTIVES: The purpose of this retrospective sleep laboratory study was to assess if any change in RMMA frequency occurs over age in the general population (GP) and two clinical research (CR) samples. METHODS: RMMA signals from polysomnography (PSG) recordings of 465 individuals, irrespective of SB awareness, were analysed. The sample comprised 164 individuals from the GP of Sao Paulo, and 301 individuals from Montreal and Osaka CR samples. Data were divided into two subgroups, younger (15-39) and older (40-80) participants. RMMA was classified as low frequency (<2 events/h) or high (≥2 events/h). Pearson correlation (R) and B (slope) analyses were performed with power estimations. RESULTS: In the GP sample, no significant change over age was noted in the RMMA index/year. In the CR samples, a significant reduction was observed in the RMMA index/year (-0.05) with age (R2  = .042; p < .001; 3.5 to 1.5 RMMA/h from 20 to 60 years old). CONCLUSIONS: In the GP, the RMMA index remained stable over age. In the CR samples, a significant, reduction was observed. Prospective studies with multiple home sleep recordings, in both general and clinical research populations, are needed before extrapolating from the present findings.

Effect of vitamin D on bone morphometry and stability of orthodontic tooth movement in rats.

INTRODUCTION: Vitamin D (VitD) maintains bone health and may influence orthodontic tooth movement (OTM). The objective was to evaluate the VitD effect on bone morphometry and the rate and stability of OTM. METHODS: Thirty-two male Sprague Dawley rats were assigned into 2 experimental groups, treated with VitD by gavage (systemic) or injection (local), and 2 respective control groups treated with phosphate-buffered saline for 47 days. OTM was performed for 7 days with a nickel-titanium coil bonded between the maxillary first molar and incisors. Microcomputed tomography scanning was performed at 5 time points: before administration of VitD, the start of OTM, the end of OTM, 7 days post-OTM, and 30 days post-OTM. The rate and stability of OTM were assessed. Bone morphometry was analyzed by bone mineral density, bone volume/total volume, total porosity, trabecular pattern factor, structure model index, and connectivity density. RESULTS: The systemic VitD group showed a lower OTM rate and a lower relapse than the control (P <0.05). It also demonstrated increased bone mineral density, bone volume/total volume, and a decrease in total porosity (P <0.05). The bone structure appeared more fragmented and presented a lower connectivity density than the control (P <0.05). No statistical difference was found between VitD local administration and the other groups for the rate and stability of OTM or bone morphometry. CONCLUSIONS: The systemic administration of VitD caused a decrease in the OTM rate by generating more bone resistance but also contributed to a lower relapse with a higher bone mineral density.

Clinical Management of Interproximal and Occlusal Caries in Children and Adolescents by Canadian Dentists: A Survey.

PURPOSE: Early restorative interventions may have important implications in young patients, and the International Caries Classification and Management System strongly recommends non-surgical strategies in the management of dental caries. We aimed to assess management of interproximal and occlusal caries in children and adolescents (≤18 years of age) by Canadian dentists. METHODS: An electronic survey was created and sent to members of Canadian provincial regulatory dental bodies. The survey included 11 questions on demographic factors and 3 clinical situations on dental caries management. RESULTS: The response rate was 4.6% (n = 702). To treat interproximal carious lesions limited to enamel, 442 dentists (63.0%) reported using surgical caries removal on a permanent molar and 502 dentists (71.5%) did the same for a primary tooth. For occlusal carious lesions, the corresponding numbers were 300 dentists (42.7%) for a permanent molar and 269 (38.3%) for a primary molar. Age, year of graduation and province of practice appear to have a significant impact on the restorative threshold. CONCLUSIONS: According to the latest evidence-based recommendations for caries management, the presence of cavitated enamel should be the main indication to restore, and non-surgical interventions for non-cavitated lesions confined to enamel should be prioritized. Results show that a good proportion of respondents have a lower restorative threshold, particularly for interproximal lesions.

Oral appliances reduce masticatory muscle activity-sleep bruxism metrics independently of changes in heart rate variability.

OBJECTIVES: Sleep bruxism (SB) is associated with physiological activities including sympathetic autonomic system dominance and sleep micro-arousal. While oral appliances (OA) are used to prevent SB harmful effects, the influence of OAs physiological mechanisms during sleep is unknown. The aim of this study is to assess whether heart rate variability (HRV) changes, as a marker of autonomic nervous system activity, would be associated with the OA mechanism of action on SB using occlusal splint (OS) and mandibular advancement splint (MAS). MATERIALS AND METHODS: A retrospective analysis, from data previously collected in 21 participants with SB (25.6 ± 4.5 years) with polysomnographic recordings, was done. HRV data were compared between a reference night (no-device) and ones during which OS or MAS was used in a crossover study design. Rhythmic masticatory muscle activity (RMMA) index was compared between nights. HRV was evaluated using autoregressive model analysis for three sections: baseline (distance from RMMA), immediately before, and after RMMA period. RESULTS: A significant reduction in RMMA index, when wearing OA during sleep, was observed (P < 0.01), but was not associated with HRV parameters change. HRV significantly changed after RMMA onset for nights with OA during non-REM sleep in comparison with baseline (P < 0.02). CONCLUSIONS: The usage of OAs for SB participants reduced RMMA, but most likely independently of changes in HRV linked to the mechanism associated with SB genesis. CLINICAL RELEVANCE: Wearing OA seems to reduce grinding noise and protect from dental injuries but does not seem to influence SB genesis.

Is the quality of occlusal contacts comparable after aligner and fixed orthodontic therapy? A non-randomized cohort comparison using computerized occlusal analysis during 6 months of retention.

OBJECTIVE: Less than ideal contacts have been reported following aligner therapy, but it is considered a transitory problem, spontaneously resolving with the phenomenon of settling. Methods: Thirty-nine orthodontic patients (14 treated with aligners; 25 with fixed appliances) were evaluated with a digital occlusal analysis system (T-scan™10), assessing Maximum Intercuspation contact simultaneity, symmetry, and relative force distribution at treatment completion and after 3 and 6 months. RESULTS: No significant differences in occlusal contact quality were found between groups at treatment completion or follow-up. The center of force moved posteriorly and remained stable after 3 months but was located more anteriorly in females (p = 0.01). One-third of patients (both groups combined) had marked contact force asymmetry even after 6 months' retention. Conclusion: Occlusal contacts were comparable at completion of treatment with aligners or brackets and after 3-6 months of retention. Settling did not improve marked asymmetry in all patients.

Effect of personalized musical intervention on burden of care in dental implant surgery: A pilot randomized controlled trial.

OBJECTIVE: To explore a personalized musical intervention's effect on burden of care during dental implants placement. METHODS: Randomized Controlled Trial in 24 dental implant surgery patients. A personalized music intervention (Music Care© application) or an audiobook control condition was administered. Burden of care (a composite outcome including self-reported anxiety, pain, and dissatisfaction felt during surgery), expected pain prior to surgery, pre- and post-surgery affect, memory of pain felt during surgery, and participants' emotional judgments of the music and audiobook listening were assessed. RESULTS: The personalized music intervention significantly reduced the burden of care for dental implant surgery (p = 0.02; d = 1.07). Both groups reported positive affect after surgery, but the music group felt better. The pain remembered after seven postoperative days was significantly lower in the music group (p = 0.02). Participants judged the music listened to during surgery as more relaxing and pleasant than the audiobook (p = 0.002 and p = 0.001, respectively). CONCLUSIONS: Personalized music intervention could be effective in decreasing patients' burden of care during dental implant surgery. These results need to be confirmed by a rigorous randomized control trial. CLINICAL SIGNIFICANCE: The burden of care associated with the pain and anxiety experienced during dental implant surgery can be reduced using a personalized and standardized music intervention. This approach may provide a simple complementary approach to improve surgical care in various settings.

Sleep stage-dependent changes in tonic masseter and cortical activities in young subjects with primary sleep bruxism.

STUDY OBJECTIVES: The present study investigated the hypothesis that subjects with primary sleep bruxism (SB) exhibit masseter and cortical hyperactivities during quiet sleep periods that are associated with a high frequency of rhythmic masticatory muscle activity (RMMA). METHODS: Fifteen SB and ten control participants underwent polysomnographic recordings. The frequencies of oromotor events and arousals and the percentage of arousals with oromotor events were assessed. Masseter muscle tone during sleep was quantified using a cluster analysis. Electroencephalography power and heart rate variability were quantified and then compared between the two groups and among sleep stages. RESULTS: The frequency of RMMA and percentage of arousals with RMMA were significantly higher in SB subjects than in controls in all stages, while these variables for nonrhythmic oromotor events did not significantly differ between the groups. In SB subjects, the frequency of RMMA was the highest in stage N1 and the lowest in stages N3 and R, while the percentage of arousals with RMMA was higher in stage N3 than stages N1 and R. The cluster analysis classified masseter activity during sleep into two clusters for masseter tone and contractions. Masseter muscle tone showed typical stage-dependent changes in both groups but did not significantly differ between the groups. Furthermore, no significant differences were observed in electroencephalography power or heart rate variability between the groups. CONCLUSION: Young SB subjects exhibited sleep stage-dependent increases in the responsiveness of RMMA to transient arousals, but did not show masseter or cortical hyperactivity during sleep.

Do postoperative antibiotics influence one-year peri-implant crestal bone remodelling and morbidity? A double-blinded randomized clinical trial.

OBJECTIVES: The primary objective of this study was to assess whether giving postoperative antibiotics to healthy patients after straightforward platform-switched implant placement would influence peri-implant crestal bone levels and postoperative morbidity after 1 year. METHODS: Thirty-eight healthy individuals were recruited in this pilot, randomized, double-blinded, placebo-controlled clinical trial. The intervention group (n = 18) received two grams of amoxicillin one hour before implant placement followed by a 7 days postoperative regimen (500 mg tid). The control group (n = 20) took the same preoperative dose of amoxicillin and an identical placebo postoperatively. Mesial and distal peri-implant crestal bone levels were measured at baseline, four months and one year later with standardized periapical radiographs. Postoperative pain severity was assessed through self-administered questionnaires for 7 days. Surgery-associated morbidities were evaluated after one, three, 16 weeks and 1 year. Descriptive and bivariate analyses were used. RESULTS: Thirty-seven participants completed the trial. At the one-year follow-up, the mean combined peri-implant crestal bone changes for the intervention (n = 18) and control (n = 19) groups were - 0.44 ± 0.41 mm and - 0.27 ± 0.56 mm, respectively. The difference between the groups (intervention-control) for mean combined crestal bone level changes was not statistically significant. There were no significant differences in surgery-associated morbidities between the intervention and control groups. The one-year implant survival rate was 100% in both groups. CONCLUSIONS: Study results suggest that a routine postoperative antibiotic regimen for healthy patients undergoing straightforward platform-switched implant placement might not be necessary to prevent postoperative peri-implant bone loss and complications.

Dopaminergic mechanisms underlying the expression of antipsychotic-induced dopamine supersensitivity in rats.

Antipsychotic treatment can produce a dopamine-supersensitive state, potentiating the response to dopamine receptor stimulation. In both schizophrenia patients and rats, this is linked to tolerance to ongoing antipsychotic treatment. In rodents, dopamine supersensitivity is often confirmed by an exaggerated psychomotor response to d-amphetamine after discontinuation of antipsychotic exposure. Here we examined in rats the dopaminergic mechanisms mediating this enhanced behavioural response, as this could uncover pathophysiological processes underlying the expression of antipsychotic-evoked dopamine supersensitivity. Rats received 0.5 mg/kg/day haloperidol via osmotic minipump for 2 weeks, before treatment was discontinued. After cessation of antipsychotic treatment, rats showed a supersensitive psychomotor response to the D2 agonist quinpirole, but not to the D1 partial agonist SKF38393 or the dopamine reuptake blocker GBR12783. Furthermore, acute D1 receptor blockade (using SCH39166) decreased the exaggerated psychomotor response to d-amphetamine in haloperidol-pretreated rats, whereas acute D2 receptor blockade (using sulpiride) enhanced it. Thus, after discontinuation of antipsychotic treatment, D1- and D2-mediated transmission differentially modulate the expression of a supersensitive response to d-amphetamine. This supersensitive behavioural response was accompanied by enhanced GSK3ß activity and suppressed ERK1/2 activity in the nucleus accumbens (but not caudate-putamen), suggesting increased mesolimbic D2 transmission. Finally, after discontinuing haloperidol treatment, neither increasing ventral midbrain dopamine impulse flow nor infusing d-amphetamine into the cerebral ventricles triggered the expression of already established dopamine supersensitivity, suggesting that peripheral effects are required. Thus, while dopamine receptor-mediated signalling regulates the expression of antipsychotic-evoked dopamine supersensitivity, a simple increase in central dopamine neurotransmission is insufficient to trigger this supersensitivity.

Impact of piezocision-assisted orthodontics on root resorption and alveolar bone: a prospective observational study.

OBJECTIVES: To assess the impact of orthodontic treatment combined with piezocision (OT-PC) on root structure and alveolar bone. MATERIALS AND METHODS: Twelve adults were treated with OT-PC. Pre- and post-treatment CBCT examinations evaluated apical root resorption (ARR) and alveolar bone height and thickness changes. Pre- and post-treatment differences were compared using one-sample t test and Wilcoxon signed-rank test. RESULTS: ARRs were generalized and significantly more severe in both anterior sextants compared with posterior sextants. Bone thickness decreased significantly in the maxilla at mid-root and apex areas. The majority of mandibular alveolar bone dehiscences occurred on the buccal aspect at the mid-root level, especially where thickness was less than 0.3 mm. Overall bone height decreased twice as much on the buccal aspect (1.43 mm, P < 0.001) compared with the lingual aspect (0.67 mm, P = 0.001), most significantly in the lower incisors, where the average median loss was 2.10 mm (P = 0.003). CONCLUSION: OT-PC causes minor negative effects on both alveolar bone and root resorption. CLINICAL RELEVANCE: Orthodontic treatment combined with piezocision causes minor negative effects on periodontal support. Nevertheless, mild bone height loss on the buccal aspect of the mandibular teeth and root resorption in both anterior sextants have been detected with this new treatment.

Effects of nocturnal wearing of dentures on the quality of sleep and oral-health-related quality in edentate elders with untreated sleep apnea: a randomized cross-over trial.

STUDY OBJECTIVES: This study aims to assess whether the nocturnal wear of dentures has an effect on the quality of sleep and oral-health-related quality of life of the edentulous elderly with untreated sleep apnea. METHODS: A single-blind randomized cross-over design with two sequences and two periods was used. Participants (n = 77) were randomly assigned either to sequence 1 (nocturnal wear followed by nocturnal nonwear of the denture for 30-30 days) or sequence 2 (nocturnal nonwear followed by nocturnal wear of denture for 30-30 days). The primary sleep outcome was the quality of sleep, assessed through sleep fragmentation measured as Apnea-Hypopnea Index (AHI) and respiratory arousal from portable polysomnography. Secondary outcomes were daytime sleepiness, sleep quality (Pittsburgh Sleep Quality Index, PSQI) and oral-health-related quality of life measured by validated questionnaires. RESULTS: The mean paired difference in AHI scores for the period of wearing versus not wearing dentures at night was small 1.0 event per hour (p = 0.50; 95% confidence interval (CI) = -2.0 to 4.1). The mean respiratory arousal index was higher when wearing dentures at night than when not wearing dentures at night, with a mean paired difference of 2.3 events per hour (p = 0.05; 95% CI = 0.0 to 4.6). No difference in sleepiness and PSQI were noted. Wearing dentures at night resulted in a statistically significantly higher mean score of psychological discomfort when compared to not wearing dentures at night. CONCLUSIONS: The results provide some support to usual practice guidelines to remove dentures at night in edentulous elders suffering from sleep apnea. CLINICAL TRIAL REGISTRATION: NCT01868295.

Sensitization to amphetamine psychostimulant effect: A key role for ventral tegmental area neurotensin type 2 receptors and MAP kinase pathway.

Neurotensin is an endogenous neuropeptide that acts as a potent modulator of ventral tegmental area (VTA) neurotransmission. The present study was aimed at determining VTA cell population and neurotensin receptor subtype responsible for the initiation of amphetamine-induced psychomotor activity and extracellular signal-regulated kinases (ERK1/2) sensitization. During an induction phase, rats were injected intra-VTA on two occasions, every second day, with [D-Tyr11 ]-neurotensin (D-Tyr-NT), SR142948 (a mix Ntsr1/Ntsr2 receptor subtype antagonist), SR48692 (a Ntsr1 antagonist), D-Tyr-NT + SR142498, D-Tyr-NT + SR48692, or the vehicle. Effects of intra-VTA drugs were evaluated at locomotor activity and ERK1/2 phosphorylation. Five days after the last VTA microinjection, the effect of a systemic injection of amphetamine was tested (sensitization test). Results show that D-Tyr-NT stimulated locomotor activity during the induction phase, an effect that was blocked by SR142948, but not SR48692. Amphetamine also induced significantly higher ambulatory activity in rats preinjected with D-Tyr-NT than in rats preinjected with the vehicle. This sensitization effect was again attenuated by SR142948, but not SR48692, hence suggesting that this effect is mediated by Ntsr2 receptors. To confirm this, we tested a highly selective Ntsr2 peptide-peptoid hybrid ligand, NT150. At the concentration tested, NT150 stimulated locomotor activity and lead to sensitized locomotor activity and a selective neurochemical (pERK1/2) response in tyrosine hydroxylase-positive neurons of the VTA. Both effects were prevented by SR142948. Taken together, these results show that neurotensin, acting on Ntsr2 receptor subtypes, stimulates locomotor activity and initiates neural changes (ERK1/2 phosphorylation) that lead to amphetamine-induced sensitization.

Prospective randomized clinical trial evaluating the effects of two different implant collar designs on peri-implant healing and functional osseointegration after 25 years.

OBJECTIVES: Evaluate the effects of two different machined-collar lengths and designs on peri-implant healing. MATERIAL AND METHODS: An implant with a microtextured surface and 3.6mm-long internal-connection machined collar was compared to two implants that had an identical 1.2mm-long external-connection machined collar, but one had the microtextured surface while the other's was machined. Participants received the three implants, with microgap at the crest, alternately at five sites between mental foramen, and a full-arch prosthesis. Peri-implant bone levels were measured after 23 to 26 years of function. Keratinized tissue height, plaque, probing depth, bleeding, and purulence were also evaluated. Descriptive and mixed models for repeated\measures analyses were used, with Bonferroni correction for pairwise comparisons. RESULTS: Twenty-two participants (110 implants) were evaluated at the 25-year examination. Microtextured implants with the longer machined collar had significantly greater mean marginal bone loss (-1.77mm ± 0.18, mean ± SE) than machined (-0.85mm ± 0.18, p < .001) and microtextured (-1.00 ± 0.18mm, p < .001) implants with the shorter machined collar. Keratinized tissue height was greater for internal-connection (0.74mm ± 0.10) versus external-connection (0.51 ± 0.08, p =  0.01) microtextured implants. No differences were observed for plaque (p = 0.78), probing depth (p = 0.42), bleeding (p  = 0.07), and purulence (p = 1.00). Implant survival rate was 99%. CONCLUSIONS: Implants with the 1.2mm machined collar limited bone loss to 1mm, while those with the longer machined collar showed > 1.5mm loss after 25 years of function with microgap at the crest. Internal-connection design and fixture surface microtexturing did not result in greater bone preservation. ClinicalTrials.gov Identifier: NCT03862482.

Dental malocclusion among children with attention deficit hyperactivity disorder.

INTRODUCTION: Children with attention deficit hyperactivity disorder (ADHD) have more sleep breathing problems and parafunctional oral habits than individuals without ADHD. However, there is scarce information on the correlation between their dental malocclusion and these functional disorders. The objective of this study was to assess the severity of malocclusion in patients with and without ADHD and to evaluate the correlation between their functional disorders and dental malocclusion. METHODS: Eighty-eight patients aged 6-17 years were divided into 2 groups: ADHD (n = 44) and control (n = 44). A medical questionnaire to assess functional disorders and an orthodontic examination to evaluate malocclusion were completed for each patient. Distribution of the data was evaluated using Shapiro-Wilk test, whereas the 2 groups were compared with a t test, Mann-Whitney U test, Fisher exact test, and Spearman correlation. The association between parafunctional oral habits, ADHD drug intake, and malocclusion severity were assessed with a t test and Mann-Whitney U test. RESULTS: Patients with ADHD had significantly higher severity of malocclusion (P = 0.042), more dental rotation (P = 0.021) and more parafunctional oral habits (P = 0.001), specifically bruxism (P = 0.005), and a history of pacifier use (P = 0.009), than the control group. CONCLUSIONS: It is important to be aware of the increased risk of parafunctional oral habits and dental malocclusion among ADHD patients to develop preventive programs, as well as therapeutic strategies for them.

The Evaluation of Autonomic Arousals in Scoring Sleep Respiratory Disturbances with Polysomnography and Portable Monitor Devices: A Proof of Concept Study.

BACKGROUND: Autonomic arousals can be considered as surrogates of electroencephalography (EEG) arousals when calculating respiratory disturbance index (RDI). The main objective of this proof of concept study was to evaluate the use of heart rate acceleration (HRa) arousals associated with sleep respiratory events in a population undergoing full polysomnography (type 1) and in another undergoing portable monitor study (type 3). Our hypothesis is that when compared to other commonly used indexes, RDI based on HRa will capture more events in both types of recording. MATERIALS AND METHODS: A retrospective analysis was performed in two different populations of patients with suspected OSA: a) 72 patients undergoing one night of type 1 recording and b) 79 patients undergoing one night of type 3 recording. Variables for type 1 were 4% oxygen desaturation index (ODI), apnea/hypopnea index (AHI), RDI based on EEG arousals (RDIe), and RDI based on HRa with threshold of 5bpm (RDIa5). For type 3, variables were 4% ODI, AHI, and RDIa5 (it is not possible to calculate RDIe due to the absence of EEG). Calculated data were 1) Mean values for each sleep disturbance index in type 1 and 3 recordings; 2) Frequency of migration from lower to higher OSA severity categories using RDIa5 in comparison to AHI (thresholds: ≥5/h mild, ≥15/h moderate, ≥30/h severe); and 3) Bland-Altman plots to assess agreement between AHI vs RDIe and RDIa5 in type 1 population, and AHI vs RDIa5 in type 3 populations. RESULTS: More respiratory disturbance events were captured with RDIa5 index in both type 1 and type 3 recordings when compared to the other indexes. In type 1 recording, when using RDIa5 37% of patients classified as not having OSA with AHI were now identified as having OSA, and a total of 59% migrated to higher severity categories. In type 3 recording, similar results were obtained, as 37% of patients classified as not having OSA with AHI were now identified as having OSA using RDIa5, and a total of 55% patients migrated to higher severity categories. Mean differences for RDIa5 and AHI in type 1 and 3 populations were similar. CONCLUSION: The use of autonomic arousals such as HRa can help to detect more respiratory disturbance events when compared to other indexes, being a variable that may help to capture borderline mild cases. This becomes especially relevant in type 3 recordings. Future research is needed to determine its validity, optimization, and its clinical significance.