Objective: To evaluate the effectiveness of interventions on accelerating orthodontic tooth movement. Materials and Methods: We searched the databases of PubMed, Embase, Science Citation Index, CENTRAL, and SIGLE from January 1990 to August 2011 for randomized or quasirandomized controlled trials that assessed the effectiveness of interventions on accelerating orthodontic tooth movement. The processes of study search, selection, and quality assessment were conducted independently in duplicate by two review authors. Original outcome data, if possible, underwent statistical pooling by using Review Manager 5. Results: Through a predefined search strategy, we finally included nine eligible studies. Among them, five interventions were studied (ie, low-level laser therapy, corticotomy, electrical current, pulsed electromagnetic fields, and dentoalveolar or periodontal distraction). Six outcomes were evaluated in these studies (ie, accumulative moved distance or movement rate, time required to move tooth to its destination, anchorage loss, periodontal health, pulp vitality, and root resorption). Conclusion: Among the five interventions, corticotomy is effective and safe to accelerate orthodontic tooth movement, low-level laser therapy was unable to accelerate orthodontic tooth movement, current evidence does not reveal whether electrical current and pulsed electromagnetic fields are effective in accelerating orthodontic tooth movement, and dentoalveolar or periodontal distraction is promising in accelerating orthodontic tooth movement but lacks convincing evidence. (Angle Orthod. 2013;83:164-171.)

Orthodontic pain is an inflammatory pain that is initiated by orthodontic force-induced vascular occlusion followed by a cascade of inflammatory responses, including vascular changes, the recruitment of inflammatory and immune cells, and the release of neurogenic and pro-inflammatory mediators. Ultimately, endogenous analgesic mechanisms check the inflammatory response and the sensation of pain subsides. The orthodontic pain signal, once received by periodontal sensory endings, reaches the sensory cortex for pain perception through three-order neurons: the trigeminal neuron at the trigeminal ganglia, the trigeminal nucleus caudalis at the medulla oblongata and the ventroposterior nucleus at the thalamus. Many brain areas participate in the emotion, cognition and memory of orthodontic pain, including the insular cortex, amygdala, hippocampus, locus coeruleus and hypothalamus. A built-in analgesic neural pathway—periaqueductal grey and dorsal raphe—has an important role in alleviating orthodontic pain. Currently, several treatment modalities have been applied for the relief of orthodontic pain, including pharmacological, mechanical and behavioural approaches and low-level laser therapy. The effectiveness of nonsteroidal anti-inflammatory drugs for pain relief has been validated, but its effects on tooth movement are controversial. However, more studies are needed to verify the effectiveness of other modalities. Furthermore, gene therapy is a novel, viable and promising modality for alleviating orthodontic pain in the future.

The objective of this systematic review was to compare the outcomes between coronectomy and total removal for third molar extractions with high risk of nerve injury and to help practitioners make prudent decisions on whether and how third molars should be removed. PubMed, Embase, Web of Science, CENTRAL, and SIGLE were searched from January 1990 to October 2011 for randomized or non-randomized controlled trials. Four studies met our inclusion criteria. The pooled risk ratio (coronectomy vs. total removal) was 0.11 (95% CI = 0.03-0.36), 1.03 (95% CI = 0.54-1.98), 0.55 (95% CI = 0.28-1.05), and 1.14 (95% CI = 0.57-2.30) for inferior alveolar nerve injury, post-operative infection, dry socket, and pain at 1 wk after surgery, respectively. A relatively high rate of failed coronectomy in one study (38.3%, compared with 2.3%-9.4% in others) may be attributed to a higher proportion of narrowing roots and vertical impactions. Although root migration rate was high (13.2%-85.29%), the migration distances were short (3.06 ± 1.67 mm), and the directions were away from the nerves. Moreover, the rates of re-operation and root exposure were low. Therefore, coronectomy appears superior to total removal for reducing inferior alveolar nerve damage and could be used in clinical practice for third molar extractions with high risk of nerve injury.

The role of epigenetic regulation in immunity is emerging, especially for RNA N6‐methyladenosine (m6A) modification. However, little is known about the role of m6A in the regulation of the immune microenvironment of periodontitis. Thus, we aim to investigate the impact of m6A modification in periodontitis immune microenvironment. The RNA modification patterns mediated by 23 m6A‐regulators were systematically evaluated in 310 periodontitis samples. The impact of m6A modification on immune microenvironment characteristics was explored, including infiltrating immunocytes, immune reaction gene‐sets and HLAs (human leukocyte antigen) gene. m6A phenotype‐related immune genes were also identified. 17 m6A regulators were dysregulated and a 15‐m6A regulator signature can well distinguish periodontitis and control samples. ALKBH5 and FMR1 are closely related to infiltrating monocyte abundance. ELAVL1 and CBLL1 are significant regulators in immune reaction of TNF_Family_Members_Receptors and Cytokine. The expression of HLA‐B and HLA‐DOA is affected by ALKBH5 and LRPPRC. 3 distinct RNA modification patterns mediated by 23 m6A regulators were identified. They differ from immunocyte abundance, immune reaction and HLA gene. 1631 m6A phenotype‐related genes and 70 m6A‐mediated immune genes were identified, and the biological functions of these were explored. Our finding demonstrated the m6A modification plays a crucial role in the diversity and complexity of the immune microenvironment of periodontitis.

Abstract Background and Objectives Clear aligner is an advanced orthodontic method with benefits of comfort, aesthetics, and convenience. This study aimed to compare pain perception, anxiety, and impacts on oral health-related quality of life (OHRQoL) between adult patients receiving clear aligners and fixed appliances during the initial stage of orthodontic treatments. Material and Methods The two groups were well matched by ages, gender, and levels of malocclusion severity. Pain perception, anxiety, and OHRQoL were assessed through visual analogue scale, state-trait anxiety inventory, and oral health impact profile-14 (OHIP-14), respectively. And the comparison of above scores was performed by two-way analysis of variance. Results A total of 110 patients (55 pairs) were enrolled in this study. Orthodontic pain levels peaked on the first day and decreased gradually afterwards in both groups, which were significantly higher in the fixed group on the first, second, fourth, and fifth days. Likewise, anxiety levels peaked on the first day and decreased thereafter, with significant difference on the 1st, 3d, 5th, 7th, and 14th days. Moreover, the OHIP-14 scores increased and peaked on the first day and then gradually decreased for both groups, which were also significantly higher in the fixed group on the 1st, 7th, and 14th days. Limitations More malocclusion types should be used for group matching. The effect of exclusion of small groups should be taken into consideration in sample size calculation. Income was significantly unbalanced between two groups due to higher cost of clear aligners, and random assignment of treatment modalities was unfeasible. Conclusions Patients treated with clear aligners experienced lower pain levels, less anxiety, and higher OHRQoL as compared to those receiving fixed appliances.