Genome-wide association study of osteonecrosis of the jaw in Danish patients receiving antiresorptive therapy for osteoporosis: A case-control study.

Background: Prior studies of the pharmacogenomics of osteonecrosis of the jaw (ONJ) have had various methodological limitations, including using candidate gene selection as their sole strategy, a small number of ONJ cases, or a study population based on an oncology setting. Objectives: The aim of our case-control study was to evaluate previously reported associations between genetic factors and ONJ, which were based on either genome-wide association studies (GWAS) or candidate gene approaches. Furthermore, we aimed to identify genetic risk factors for ONJ by using GWAS to determine single-nucleotide polymorphisms (SNPs) with statistically significant differences in frequency between ONJ patients and osteoporosis controls. Methods: Patients with medically confirmed ONJ and who were registered in the Scandinavian Cohort of ONJ patients were included. Controls from the general population were matched on age (±5 years), sex, and cumulative antiresorptive drug exposure. The ONJ diagnosis date for cases corresponded to the index date for matched controls. DNA isolation, genotyping, and data analyses were performed by Q2/EA Genomics using standard protocols and best practices. Blood or tissue samples for 55 ONJ cases and 125 controls were collected. Due to the low quality of the tissue samples, final analyses were based on blood samples of 40 ONJ cases and 124 controls. Results: We detected no significant genome-wide associations. Of the 43 SNPs with ONJ association in prior studies, none were replicated in our study. Conclusions: Even though our study sample is the largest to date, we had limited statistical power for GWAS but adequate power for replication analyses. Our study provides no evidence for any genetic predisposition to ONJ. Future studies could increase their statistical power by combining ONJ GWAS datasets and by performing a meta-analysis or pursuing a sequencing strategy in order to identify rare variants.

Assessment of Somatosensory and Psychosocial Function of Patients With Trigeminal Nerve Damage.

OBJECTIVE: The present study assessed somatosensory changes related to trigeminal nerve damage using extensive evaluation tools and assessed the effect of such damage on the patients' psychosocial status and quality of life compared with healthy participants. METHODS: In 37 patients with intraorally or extraorally presenting trigeminal nerve damage diagnosed as painful or nonpainful posttraumatic trigeminal neuropathy, psychophysical tests like quantitative sensory testing (QST) and qualitative sensory testing and the electrophysiological "nociceptive-specific" blink reflex were performed. The patients and 20 healthy participants completed a set of questionnaires assessing their psychosocial status and quality of life. RESULTS: A loss or gain of somatosensory function was seen in at least 1 QST parameter in >88.9% of the patients. Patients in whom extraoral QST was performed showed an overall loss of somatosensory function, whereas intraoral QST showed a general gain of somatosensory function. Qualitative sensory testing identified a side-to-side difference in the tactile and pinprick stimulation in >77% of the patients. An abnormal "nociceptive-specific" blink reflex response was seen in 42.1% to 71.4% of patients dependent on the trigeminal branch stimulated, though comparisons with healthy reference values showed ambiguous results. Compared with the healthy participants, patients showed higher scores for pain catastrophizing, symptoms of depression and anxiety, limited jaw function, more somatic symptoms, and significantly impaired oral health-related quality of life (all P<0.038). DISCUSSION: The results from the present study showed presence of varied somatosensory abnormalities when assessed using psychophysical and electrophysiological investigations and a significantly impaired psychosocial status.

Do Infant Cleft Dimensions Have an Influence on Occlusal Relations? A Subgroup Analysis Within an RCT of Primary Surgery in Patients With Unilateral Cleft Lip and Palate.

AIM: To investigate whether infant cleft dimensions, in a surgical protocol with early or delayed hard palate closure, influence occlusion before orthodontics. DESIGN: Subgroup analysis within a randomized trial of primary surgery (Scandcleft). SETTING: Tertiary health care. One surgical centre. PATIENTS AND METHODS: A total of 122 unilateral cleft lip and palate infants received primary cheilo-rhinoplasty and soft palate closure at age 4 months and were randomized for hard palate closure at age 12 versus 36 months. A novel 3D analysis of cleft size and morphology was performed on digitized presurgical models. Occlusion was scored on 8-year models using the modified Huddarth-Bodenham (MHB) Index and the Goslon Yardstick. MAIN OUTCOME MEASUREMENTS: Differences in MHB and Goslon scores among the 2 surgical groups adjusted for cleft size. RESULTS: The crude analysis showed no difference between the 2 surgical groups in Goslon scores but a better MHB (P = .006) for the group who received delayed hard palate closure. When adjusting for the ratio between cleft surface and palatal surface (3D Infant Cleft Severity Ratio) and for posterior cleft dimensions at tuberosity level, the delayed hard palate closure group received 3.65 points better for MHB (confidence interval: 1.81; 5.48; P < .001) and showed a trend for reduced risk of receiving a Goslon of 4 or 5 (P = .052). For posterior clefts larger than 9 mm, the Goslon score was better in the delayed hard palate closure group (P = .033). CONCLUSIONS: Seen from an orthodontic perspective, when the soft palate is closed first, and the cleft is large, the timing of hard palate closure should be planned in relation to posterior cleft size.

Analgesic efficacy of quick-release versus standard lornoxicam for pain after third molar surgery: a randomized, double-blind, placebo-controlled, single-dose trial.

OBJECTIVE: The aim of this study was to evaluate the analgesic efficacy and time to onset of effect of the lornoxicam quick-release (LNX-QR) tablet compared with the standard-release tablet (LNX-ST). METHODS: In this randomized, double-blind, single-dose trial, 200 patients with moderate pain after surgical removal of an impacted third molar were randomized to treatment with an LNX-QR 8 mg tablet (80 patients), an LNX-ST 8 mg tablet (80 patients) or placebo (40 patients). Pain intensity (PI) and pain relief (PAR) were assessed (numerical and verbal rating scales) for 6 hours, and time to onset of PAR was recorded. The cumulated sum of PI differences (SPID) and PAR (TOTPAR) were calculated. Tolerability was evaluated by occurrence of adverse events. RESULTS: Kaplan-Meier analysis of time to onset of analgesic efficacy demonstrated a significantly faster onset with LNX-QR than placebo or LNX-ST (p < 0.0001). Median time of onset was 32 minutes (range 29-37) for LNX-QR and 46 minutes (range 37-59) for LNX-ST. The analgesic efficacy of LNX-QR and LNX-ST were superior to that of placebo, whereas paired comparisons of TOTPAR and SPID showed LNX-QR to be superior to LNX-ST (p < 0.05). CONCLUSION: LNX-QR provided a faster onset and superior analgesic effect against pain following third molar surgery than LNX-ST.

Central sensitization phenomena after third molar surgery: a quantitative sensory testing study.

BACKGROUND: Surgical removal of third molars may carry a risk of developing persistent orofacial pain, and central sensitization appears to play an important role in the transition from acute to chronic pain. AIM: The aim of this study was to investigate sensitization (primarily central sensitization) after orofacial trauma using quantitative sensory testing (QST). METHODS: A total of 32 healthy men (16 patients and 16 age-matched control subjects) underwent a battery of quantitative tests adapted to the trigeminal area at baseline and 2, 7, and 30 days following surgical removal of a lower impacted third molar. RESULTS: Central sensitization for at least one week was indicated by significantly increased pain intensity evoked by intraoral repetitive pinprick and electrical stimulation (p<0.05) including facilitation of temporal summation mechanisms (p<0.05), extraoral repetitive electrical stimulation (p<0.001), significantly more frequent aftersensation in patients (p<0.001), extraoral hyperalgesia due to single pinprick stimulation (p<0.05) and larger pain areas due to intranasal stimulation (p<0.001). Peripheral sensitization was indicated by intraoral hyperalgesia due to single pinprick (p<0.05). CONCLUSION: We found clear signs of sensitization of the trigeminal nociceptive system for at least one week after the surgery. Our results indicate that even a minor orofacial surgical procedure may be sufficient to evoke signs of both central and peripheral sensitization, which may play a role in the transition from acute to chronic pain in susceptible individuals.

Analgesic efficacy and safety of intravenous paracetamol (acetaminophen) administered as a 2 g starting dose following third molar surgery.

BACKGROUND: The recommended dose for intravenous (IV) paracetamol injection in adults is 1g, however pharmacokinetic and pharmacodynamic findings suggest that a better analgesia could be obtained with a 2 g starting dose. METHODS: A single-centre, randomised, double-blind, placebo-controlled, 3-parallel group study was performed to demonstrate the analgesic efficacy and safety of IV paracetamol 2 g. Following third molar surgery, patients reporting moderate to severe pain received a single 15-min infusion of either IV paracetamol 2 g, IV paracetamol 1g or placebo. Efficacy and safety were evaluated over 8 h. Laboratory tests were performed before and 48 h after drug administration. RESULTS: Two hundred and ninety seven patients (132 = IV paracetamol 2g; 132 = IV paracetamol 1g; 33 = placebo) were randomised and completed the study. The summed pain relief over 6h (TOTPAR6) was significantly superior with IV paracetamol 2 g as compared to IV paracetamol 1g and placebo (p < 0.0001). Pain relief scores of IV paracetamol 2g were significantly superior to IV paracetamol 1g and to placebo from T30' to T8h (p < 0.0001). Median duration of analgesia was significantly longer following IV paracetamol 2 g compared to IV paracetamol 1g and placebo (p < 0.0001). Adverse events occurred with the same frequency in the 3 treatment groups. No clinically significant changes from baseline were observed for vital signs or laboratory tests. CONCLUSION: The analgesic efficacy of a 2 g starting dose of IV paracetamol was superior over the recommended dose of 1g in terms of magnitude and duration of analgesic effect for postoperative pain following third molar surgery, with no significant difference between groups regarding safety.