Comparison of Self-Perception of Esthetics and Orthodontic Treatment Needs among Dental and Non-Dental Students with Assessment by Orthodontist

Objectives: The present study was conducted to compare the self-perception of esthetics and wish for seeking orthodontic treatment among dental and non-dental students. The realistic orthodontic treatment needs were confirmed by expert orthodontist. Methods: A cross-sectional study was conducted among 255 male students (Dental—75, Medical—93 and Pharmacy—87 students). The questionnaire included 20 items covering dental esthetics self-perception (10 questions), self-confidence and psychological impact (5 questions), and the need for seeking orthodontic treatment (5 questions) on a five-point Likert scale. The realistic orthodontic treatment needs were confirmed by photographs using aesthetic component of IOTN and clinical examination for the participants and analysis of jaw models using Dental aesthetic index (DAI). Kruskal-Wallis ANOVA was used to check the significant difference between groups. Results: The overall average esthetic self-perception score for total sample was 3.83. The overall average psychological impact score for the whole sample was 2.67. The total percentage of participants who either agree or strongly agree with the question related to their perception of need for seeking orthodontic treatment was 70%. According to the assessment of orthodontic needs using AC-IOTN, 19.8% required definitive treatment. According to the assessment of orthodontic treatment needs based on DAI, 20.3% and 9.9% needed highly desirable (DAI 31 - 35) and definite need of treatment (DAI ≥ 36) respectively. Conclusion: It can be concluded that there was no difference between the esthetic perception of dental and non-dental students. The self-perception for seeking orthodontic treatment was over-reported by participants compared to real requirement as assessed by orthodontic specialist. Dental esthetics has no psychological impact on academic performance and self-confidence as perceived by study participants.

Low-intensity pulsed ultrasound reduces alveolar bone resorption during orthodontic treatment via Lamin A/C-Yes-associated protein axis in stem cells

BACKGROUND The bone remodeling during orthodontic treatment for malocclusion often requires a long duration of around two to three years,which also may lead to some complications such as alveolar bone resorption or tooth root resorption.Low-intensity pulsed ultrasound(LIPUS),a noninvasive physical therapy,has been shown to promote bone fracture healing.It is also reported that LIPUS could reduce the duration of orthodontic treatment;however,how LIPUS regulates the bone metabolism during the orthodontic treatment process is still unclear.AIM To investigate the effects of LIPUS on bone remodeling in an orthodontic tooth movement(OTM)model and explore the underlying mechanisms.METHODS A rat model of OTM was established,and alveolar bone remodeling and tooth movement rate were evaluated via micro-computed tomography and staining of tissue sections.In vitro,human bone marrow mesenchymal stem cells(hBMSCs)were isolated to detect their osteogenic differentiation potential under compression and LIPUS stimulation by quantitative reverse transcription-polymerase chain reaction,Western blot,alkaline phosphatase(ALP)staining,and Alizarin red staining.The expression of Yes-associated protein(YAP1),the actin cytoskeleton,and the Lamin A/C nucleoskeleton were detected with or without YAP1 small interfering RNA(siRNA)application via immunofluorescence.RESULTS The force treatment inhibited the osteogenic differentiation potential of hBMSCs;moreover,the expression of osteogenesis markers,such as type 1 collagen(COL1),runt-related transcription factor 2,ALP,and osteocalcin(OCN),decreased.LIPUS could rescue the osteogenic differentiation of hBMSCs with increased expression of osteogenic marker inhibited by force.Mechanically,the expression of LaminA/C,F-actin,and YAP1 was downregulated after force treatment,which could be rescued by LIPUS.Moreover,the osteogenic differentiation of hBMSCs increased by LIPUS could be attenuated by YAP siRNA treatment.Consistently,LIPUS increased alveolar bone density and decreased vertical bone absorption in vivo.The decreased expression of COL1,OCN,and YAP1 on the compression side of the alveolar bone was partially rescued by LIPUS.CONCLUSION LIPUS can accelerate tooth movement and reduce alveolar bone resorption by modulating the cytoskeleton-Lamin A/C-YAP axis,which may be a promising strategy to reduce the orthodontic treatment process.

Effect of different interventions on orthodontic tooth movement acceleration:A network meta-analysis

Objective: To explore the effectiveness of various interventions in accelerating tooth movement, a systematic review and net-work meta analysis were used to draw a conclusion. Methods: MEDLINE, EMBASE, Willey Library, EBSCO, Web of Science Databases, and Cochrane Central Register of Controlled Trials databases to identify relevant studies. ADDIS 1.16.6 and Stata 16.0 software were used for NMA. Results: Five thousand five hundred and forty-two articles were searched out. After screening by two independent investigators, forty-seven randomized controlled trials, 1 390 participants, were included in this network meta-analysis. A total of 11 interventions involving Piezocision (Piezo), Photobiomodulation therapy (PBMT), Plate- let-rich plasma(PRP), Electromagnetic field(EF), Low intensity laser therapy(LLLT), Low intensity pulsed ultrasound(LI-PUS), Low-frequency vibrations(LFV), Distraction osteogenesis(DAD), Corticotomy(Corti), Microosteoperforations (MOPS), Traditional orthodontic(OT)were identified and classified into 3 classes including surgical treatment, non-surgical treatment and traditional orthodontic treatment. According to SUCRA probability ranking of the best intervention effect, when orthodontic treatment lasted for 1 month, PBMT (90.6%), Piezo(87.4%) and MOPs(73.6%)were the top three interventions to improve the efficiency of canine tooth movement. When orthodontic treatment lasted for 2 months, Corti (75.7%), Piezo (69.6%) and LFV(58.9%)were the top three interventions for improving the mobility efficiency of canine tooth movement. When orthodontic treatment lasted for 3 months, Cort (73.3%), LLLT(68.4%)and LFV(60.8%)were the top three interventions for improving the mobility efficiency of canine tooth movement. Conclusion: PBMT and Piezo can improve the efficiency of canine tooth movement significantly after 1 month, while Corti and LFV can improve the efficiency of canine tooth movement better after 2 and 3 months.

Oral Hygiene in the Presence of Orthodontic Therapy

Orthodontic treatment offers great advantages in improving facial and smile aesthetics, self-confidence and the function of the stomatognathic apparatus. The pursuit of these advantages makes use of orthodontic appliances that could be fixed or removable. However, it’s worth stating that these appliances interfere with tooth brushing, making it more difficult to brush teeth effectively. Orthodontics appliances therefore promote the accumulation of dental plaque, which results in both quantitative and qualitative changes in the oral microbiota, hence, exposing patients to several adverse effects such as White spot lesions, dental caries, periodontal pathologies and halitosis. For this reason, oral assessment of patients before, during and after treatment is necessary as well as oral hygiene instructions and motivation. Orthodontists therefore, should educate patients on oral and periodontal hygiene in order to control dental and periodontal complications. Prescriptions of plaque control materials adapted to each patient are done in order to optimize the final result and minimize unwanted complications.

Challenges and Motivating Factors of Orthodontic Treatment among Patients Attending Komfo Anokye Teaching Hospital

Background: Orthodontic treatment poses challenges such as discomfort, aesthetic concerns, dietary restrictions, time commitment, and financial considerations for patients. These challenges can deter individuals from pursuing treatment or cause anxiety during the process. However, patients are motivated by the desire to improve their appearance, boost self-confidence, and enhance oral health. They also value the long-term benefits of treatment, including improved dental function and overall well-being. Professional recommendations from dentists and orthodontists, along with social support from family and friends, further encourage patients to undergo treatment. Understanding these challenges and motivating factors is crucial for orthodontic professionals to tailor treatment plans and ensure positive experiences and successful outcomes for their patients. Objective: To determine the challenges and motivating factors of orthodontic treatment among patients attending Komfo Anokye Teaching Hospital. Method: The study was conducted at Komfo Anokye Teaching Hospital in Kumasi, Ghana, with a sample size of 60 orthodontic patients. Data was collected using self-administered questionnaires and analyzed using SPSS software. Ethical approval was obtained, and the findings were shared with stakeholders. Results: Findings showed a higher representation of females (63.3%) seeking orthodontic treatment. Common motivations for seeking orthodontic treatment included aesthetic Concerns (38.2%), misaligned teeth (28.1%) and recommendation from dentist (19.2%). Challenges reported included pain and discomfort (36.7%), difficulty chewing (15%), expensive treatment (14.4%) and missed appointments (11.7%). Factors motivating treatment continuation were visible improvements (30%), achieving optimal results (23%), reducing pain and discomfort (17%). External influences, such as family pressure, also played a role. Patients appreciated the support of healthcare providers during treatment but suggested better pain management and education. Conclusion: The study provided valuable insights into patient motivations, challenges and factors influencing satisfaction and adherence to orthodontic treatment at KATH.

Knowledge and Attitudes of Knust Pre-Clinical Dental Students towards Orthodontic Treatment

Background: Orthodontics is a dental specialty focusing on correcting dental irregularities and malocclusion. Knowledge and attitudes towards orthodontic treatment are crucial for promoting oral health and overall well-being. Education and awareness play a vital role in ensuring optimal treatment outcomes and improving quality of life. Aim: This study aims to determine the knowledge and attitudes of Kwame Nkrumah University of Science and Technology (KNUST) pre-clinical dentistry students concerning orthodontic therapy. Methodology: This research is a quantitative descriptive cross-sectional study. The research used a non-random convenience sampling method to form the desired sample. For data collection, an interview-administered questionnaire was used over one month. The study set its sights on pre-clinical dental students in KNUST. A total of 150 questionnaires were printed to meet the sample size. Results: The results of the research showed that the knowledge level of KNUST pre-clinical students on orthodontic treatment and its nuances is quite limited. They however had a fair level of knowledge on the disease or ailment that orthodontic treatments solved (especially malocclusion). Their interest in orthodontic treatments on the other hand was quite significant, with a large number having interest in it. Conclusion: To conclude, KNUST pre-clinical students in Ghana although having a limited level of knowledge on orthodontic treatments have a keen interest in undergoing them regardless of the discomforts or the length of time.

Effect of Dietary Components on the Shear Bond Strength of Orthodontics Brackets after Thermal Aging

Introduction: The stability of orthodontic brackets throughout orthodontic treatment plays a critical role in the treatment’s effectiveness. The present in vitro study was designed to assess the impact of various dietary components on the performance of orthodontic brackets. Methods: Metal orthodontic brackets were bonded to 66 extracted anterior teeth divided into groups based on the solution type: Milk, Gatorade, Cold Coffee, and a control group using water. Each group consisted of 20 teeth except for the control group, which included six teeth. The bracketed teeth were submerged in their respective solutions for 15 minutes three times daily at different intervals to mimic an in vivo environment and were stored in artificial saliva at room temperature (23?C). The specimens underwent artificial aging through 10,000 cycles of thermocycling (representing one clinical year) between 5?C and 55?C. Shade measurements were taken using a VITA Easy Shade device, capturing the classic shade and L*, a*, and b* values. Delta E values were calculated immediately post-bonding and after 7 days, 1 month, 1, and 2 clinical years. The shear bond strength of each bracket was measured using an ultra-tester machine. Results: After two clinical years, significant differences in ΔE color values were observed across all groups, with the most substantial change noted in teeth immersed in cold coffee. Brackets submerged in milk demonstrated lower shear bond strength than other solutions, whereas the control group exhibited the highest shear bond strength (P = 0.01). Conclusion: The study indicates that dietary components significantly influence tooth color stability and the shear bond strength of orthodontic brackets, underscoring the importance of considering these factors in orthodontic treatment planning.

Factors Influencing Subjective Orthodontic Treatment Need and Culture-related Differences among Chinese Natives and Foreign Inhabitants

Aim The aim of this survey was to compare Chinese natives and foreign inhabitants in Chengdu, China, with respect to： （1） attitudes towards dental appearance, （2） subjective orthodontic treatment need, and （3） the main factors influencing orthodontic treatment need. Methodology A total of 522 subjects, including 227 foreign inhabitants and 295 Chinese natives in Chengdu participated in the survey. A simple random sampling method was adopted and a face-to-face interview was conducted at some public sites using a questionnaire. Data was entered by two persons synchronously using Epidata 3.0, and SPSS 13.0 was used to analyze these data. Results 89.0% of foreign inhabitants were satisfied with their teeth compared to only 46.8% of Chinese natives. Females were more dissatisfied with their teeth than males. Chinese natives put improving appearance as the top priority （55.9%） for seeking orthodontic treatment; however, in foreign inhabitants, the main reason for seeking treatment was to improve masticatory function（44.1%）, followed by ＂to be pretty＂ （35.2%）. The importance of well-aligned teeth and self-perception of psychosocial impact of malocclusion were the same two main factors influencing subjective orthodontic treatment need （P〈0.05） in foreign inhabitants and Chinese natives. Sub- jective orthodontic treatment need between the two target groups was significantly different （P〈0.05）. Conclusion （1） It was very common that Chinese natives were dissatisfied with their dental appearance, and their subjective orthodontic treatment needs were high. （2） There were some differences in orthodontic treatment motives between the two target groups. （3） There were differences in subjective orthodontic treatment needs between foreign inhabitants and Chinese natives. However, the prominent influential factors were almost the same. There may be benefit to understanding subjective orthodontic needs of different races.

Prevalence of Malocclusions and Normative Orthodontic Treatment Need Using IOTN Index for Patients in Yalgado Ouédraogo Teaching Hospital

Introduction: The assessment of health care needs must be reproducible, independent of the operator, hence the use of indexes like the Index of Orthodontic Treatment Need (IOTN). The aim of this study was to assess both, the prevalence of malocclusions among patients received in the Dental Surgery Unitat Yalgado Ouédraogo Teaching Hospital and their care needs according to IOTN index. Materials and Methods: It is a prospective, cross-cutting diagnostic study of malocclusions at Yalgado Ouédraogo Teaching Hospital (CHUYO), conducted from January 1 to December 31, 2016. The examiner with an examination tray records on the 12- to 16-year-old patients’ medical recorded, the variables based on the polychromatic pictures series, the IOTN rule, and the dental health component table. Results: On the whole, 81 patients were included, with 60.5% of girls and 39.5% of boys. 16- and 12-year-old patients were dominant. The average age was 14.05 years old. Various types of malocclusions were encountered. The need for orthodontic care was 56.8%. For 14 patients, 17.28%, their aesthetic component score is higher than the assessment made by the orthodontist. Conclusion: Aesthetics was an important factor in the need for orthodontic care. The aesthetic deficit entails a psychological impact that should be taken into account in the assessment of care needs.

Evaluation of Orthodontic Treatment Needs among Widou Schoolchildren in Ferlo (SENEGAL): A Transversal Study

The aim of this study was to evaluate orthodontic treatment needs among Ferlo scholars. The design of the study was descriptive and transversal. For Inclusion criteria, children must live in Widou or live around Widou’s school at least 6 km, be students at primary school of Widou Thiengoly, have a general health state which permits a clinical oral examination and teacher’s and/or parent’s agreement. The investigation was exhaustive and concerned the only school of the locality. More of 4/5 schoolchildren was 10.25 years ± 2.15 old. The majority (83.74%) of children presented an overjet between 0 and 3.5 mm, 1.63% presented a crossbite and 15.45% had OIM and RC different over to 2 mm. More of 30% of schoolchildren presented an overbite between 1 and 2 mm. More of 1/10 of them had an aesthetic teeth perception classified levels 8.9 and 10 corresponding to an orthodontic treatment needed according to IOTN while 20.33% had a score of 4 and 3.25% recorded score of 5 corresponding to a high treatment needed according to IOTN. The results of this study reveal that people need to be informed better about the therapeutic possibilities that orthodontics offer.

Transforming Adolescent Smiles:Correcting Skeletal Mandibular Retrusion and Bimaxillary Protrusion with Clear Aligners

Maxillary protrusion combined with mandibular retraction is a highly prevalent but extremely complex maxillofacial deformity that can have a serious negative impact on patients’facial aesthetics and mental health.The traditional orthodontic treatment strategy often involves extracting 4 first premolars and conventional fixed techniques,combined with mini-implant screws,to retract the anterior teeth and improve facial protrusion.In recent years,an invisible orthodontic technique,without brackets,has become increasingly popular.However,while an invisible aligner has been used in some cases with reasonable results,there remain significant challenges in achieving a perfect outcome.This case report presents an adolescent patient with bimaxillary protrusion and mandibular retrognathia.Based on the characteristics of the invisible aligners and the growth characteristics of the adolescent’s teeth and jawbone,we designed precise three-dimensional tooth movement and corresponding resistance/over-correction for each tooth,while utilizing the patient’s jawbone growth potential to promote rapid development of the mandible,accurately and efficiently correcting bimaxillary protrusion and skeletal mandibular retrognathia.The patient’s facial aesthetics,especially the lateral morphology,have been greatly improved,and various aesthetic indicators have also shown significant changes,and to the patient’s great benefit,invasive mini-implant screws were not used during the treatment.This case highlights the advantages of using invisible aligners in adolescent maxillary protrusion combined with mandibular retraction patients.Furthermore,comprehensive and accurate design combined with good application of growth potential can also enable invisible orthodontic technology to achieve perfect treatment effects in tooth extractions,providing clinical guidance for orthodontists.

Is it possible to anchor a tooth with photobiomodulation?

During orthodontic treatment,we can achieve differential movements by using photobiomodulation(PBM)as an adjuvant before applying force.We can expect a greater bone density that initially resists movement while applying PBM to the other teeth to achieve an accelerating effect.The proposed protocol is to use an 810 nm laser at 0.1W power,applying between 4 and 6J per tooth for 22 s on the vestibular and lingual root surfaces,following the axial axis of the tooth.The energy density depends on the tip selected in the instrument.Normal bone remodeling cannot be avoided by applying high doses of PBM.PBM should be applied before orthodontic force to reduce tooth movement.In addition,PBM can be used during force application to teeth that require acceleration to achieve differential movement in orthodontic treatments.The protocol is the same in both scenarios.

Prospects of 3D Printing Technology in Dental Medicine

With the continuous advancement of technology,the application of 3D printing technology in the field of dental medicine is becoming increasingly widespread.This article aims to explore the current applications and future potential of 3D printing technology in dental medicine and to analyze its benefits and challenges.It first introduces the current state of 3D printing technology in dental implants,crowns,bridges,orthodontics,and maxillofacial surgery.It then discusses the potential applications of 3D printing technology in oral tissue engineering,drug delivery systems,personalized dental prosthetics,and surgical planning.Finally,it analyzes the benefits of 3D printing technology in dental medicine,such as improving treatment accuracy and patient comfort,and shortening treatment times,while also highlighting the challenges faced,such as costs,material choices,and technical limitations.This article aims to provide a reference for professionals in the field of dental medicine and to promote the further application and development of 3D printing technology in this area.

Effect of orthodontic force on inflammatory periodontal tissue remodeling and expression of IL-6 and IL-8 in rats

Objective:To investigate effect of orthodontic force on inflammatory periodontal tissue remodeling and expression of IL-6 and IL-8 in rats.Methods:Eighty SD rats were randomly divided into 4 groups,blank control group(group A)with 5 rats,treatment normal group(group B)with 25 rats,inflammation control group(group(group C)with 25 rats,inflammation treatment group(group D)with 25 rats.Immunohistochemistry and histomorphometric analysis was performed to measure the expression of IL-6,IL-8 and the firet molar to the recent movement in the distance.Results:The expression of IL-8 reached a maximum on day 5 and declined thereafter in group B;the expression of IL-6 reached a maximum on day 5 in group B.The expression of IL-6 and IL-8 was gradually weakened with time in group C.The expression of IL-6 and IL-8 were high,and reached a maximum on day 5 and declined thereafter in group D.AD of positive cells in group D were higher than group B at each time point(P<0.05).The time which 0.49 N orthodontic force was loaded was longer,orthodontic tooth movement distance was greater.Movement distance in group D were longer than group B(P<0.05).Conclusions:Orthodontic force as well as inflammatory stimulus can evoke the expression of IL-6 and IL-8.Under the combined effects of inflammation and orthodontic force,the expression of IL-6,IL-8will increase.

Applications of stem cells in orthodontics and dentofacial orthopedics:Current trends and future perspectives

A simple overview of daily orthodontic practice involves use of brackets, wires and elastomeric modules. However, investigating the underlying effect of orthodontic forces shows various molecular and cellular changes. Also, orthodontics is in close relation with dentofacial orthopedics which involves bone regeneration. In this review current and future applications of stem cells(SCs) in orthodontics and dentofacial orthopedics have been discussed. For craniofacial anomalies, SCs have been applied to regenerate hard tissue(such as treatment of alveolar cleft) and soft tissue(such as treatment of hemifacial macrosomia). Several attempts have been done to reconstruct impaired temporomandibular joint. Also, SCs with or without bone scaffolds and growth factors have been used to regenerate bone following distraction osteogenesis of mandibular bone or maxillary expansion. Current evidence shows that SCs also have potential to be used to regenerate infrabony alveolar defects and move the teeth into regenerated areas. Future application of SCs in orthodontics could involve accelerating tooth movement, regenerating resorbed roots and expanding tooth movement limitations. However, evidence supporting these roles is weak and further studies are required to evaluate the possibility of these ideas.

Periodontally accelerated osteogenic orthodontics with platelet-rich fibrin in an adult patient with periodontal disease:A case report and review of literature

BACKGROUND In the clinical scenario,adult patients with periodontal diseases and dental malformation,characterized by dental crowding in lower anterior teeth with the thin biotype,often require orthodontic treatment.This case report aimed to evaluate the clinical and radiographic outcomes of periodontally accelerated osteogenic orthodontics(PAOO)combined with autologous platelet-rich fibrin(PRF)in an adult patient with class I malocclusion along with dental crowding,a thin periodontal biotype,and buccal plate deficiency.CASE SUMMARY A 32-year-old female complaining of dental crowding and gingival bleeding was referred to the orthodontic clinic.The patient underwent periodontal risk assessment prior to orthodontic treatment.She was diagnosed with a high risk of gingival recession due to dental crowding,root prominence,loss of buccal plates,and a thin gingival tissue biotype.The treatment regimen included PAOO combined with autologous PRF for alveolar augmentation and interproximal enamel reduction for moderate dental crowding.Clinically,PAOO-assisted orthodontic tooth movement in this case showed enhanced periodontium remodeling.Radiographic outcomes also showed statistically significant improvements(P<0.01)in the mandibular buccal alveolar bone.CONCLUSION This case report suggests the combination of autologous PRF with PAOO to enhance bone augmentation and long-term tissue support in adult orthodontic patients with periodontal disease.

Colour stabilities of three types of orthodontic clear aligners exposed to staining agents

The aim of this study was to evaluate and compare the colour stabilities of three types of orthodontic clear aligners exposed to staining agents in vitro. Sixty clear orthodontic aligners produced by three manufacturers （Invisalign, Angelalign, and Smartee） were immersed in three staining solutions （coffee, black tea, and red wine） and one control solution （distilled water）. After 12-h and 7-day immersions, the aligners were washed in an ultrasonic cleaner and measured with a colourimeter. The colour changes （△E＊） were calculated on the basis of the Commission Internationale de I＇Eclairage L＊a＊b＊ colour system （CIE L＊a＊b＊）, and the results were then converted into National Bureau of Standards （NBS） units. Fourier transformation infrared （FT-IR） spectroscopy and scanning electron microscopy （SEM） were conducted to observe the molecular and morphologic alterations to the aligner surfaces, respectively. The three types of aligners exhibited slight colour changes after 12 h of staining, with the exception of the Invisalign aligners stained with coffee. The Invisalign aligners exhibited significantly higher AE＊ values （ranging from 0.30 to 27.81） than those of the Angelalign and Smartee aligners （AE＊ values ranging from 0.33 to 1.89 and 0.32 to 1.61, respectively, P〈O.05）. IFT-IR analysis confirmed that the polymer-based structure of aligners did not exhibit significant chemical differences before and after the immersions. The SEM results revealed different surface alterations to the three types of aligner materials after the 7-day staining. The three types of aesthetic orthodontic appliances exhibited colour stability after the 12-h immersion, with the exception of the Invisalign aligners stained by coffee. The Invisalign aligners were more prone than the Angelalign and Smartee aligners to pigmentation. Aligner materials may be improved by considering aesthetic colour stability properties.

Effect of low-level laser therapy on tooth-related pain and somatosensory function evoked by orthodontic treatment

Low-level laser therapy(LLLT) may have an effect on the pain associated with orthodontic treatment. The aim of this study was to evaluate the effect of LLLT on pain and somatosensory sensitization induced by orthodontic treatment. Forty individuals(12–33 years old; mean ± standard deviations: 20.8 ± 5.9 years) scheduled to receive orthodontic treatment were randomly divided into a laser group(LG) or a placebo group(PG)(1:1). The LG received LLLT(810-nm gallium-aluminium-arsenic diode laser in continuous mode with the power set at 400 mW, 2 J·cm–2) at 0 h, 2 h, 24 h, 4 d, and 7 d after treatment, and the PG received inactive treatment at the same time points. In both groups, the non-treated side served as a control. A numerical rating scale(NRS) of pain, pressure pain thresholds(PPTs), cold detection thresholds(CDTs), warmth detection thresholds(WDTs), cold pain thresholds(CPTs), and heat pain thresholds(HPTs) were tested on both sides at the gingiva and canine tooth and on the hand. The data were analysed by a repeated measures analysis of variance(ANOVA). The NRS pain scores were significantly lower in the LG group(P = 0.01). The CDTs,CPTs, WDTs, HPTs, and PPTs at the gingiva and the PPTs at the canine tooth were significantly less sensitive on the treatment side of the LG compared with that of the PG(P < 0.033). The parameters tested also showed significantly less sensitivity on the nontreatment side of the LG compared to that of the PG(P < 0.043). There were no differences between the groups for any quantitative sensory testing(QST) measures of the hand. The application of LLLT appears to reduce the pain and sensitivity of the tooth and gingiva associated with orthodontic treatment and may have contralateral effects within the trigeminal system but no generalized QST effects. Thus, the present study indicated a significant analgesia effect of LLLT application during orthodontic treatment.Further clinical applications are suggested.

Regular nicotine intake increased tooth movement velocity,osteoclastogenesis and orthodontically induced dental root resorptions in a rat model

Orthodontic forces have been reported to significantly increase nicotine-induced periodontal bone loss. At present, however, it is unknown, which further （side） effects can be expected during orthodontic treatment at a nicotine exposure corresponding to that of an average European smoker. 63 male Fischer344 rats were randomized in three consecutive experiments of 21 animals each （A/B/C） to 3 experimental groups （7 rats, 112/3）. （A） cone-beam-computed tomography （CBCT）; （B） histology/serology; （C） reverse- transcription quantitative real-time polymerase chain reaction （RT-qPCR）/cotinine serology--（1） control; （2） orthodontic tooth movement （OTM） of the first and second upper left molar （NiTi closed coil spring, 0.25 N）; （3） OTM with 1.89 mg-kg- 1 per day s.c. of L（- ）-nicotine. After 14 days of OTM, serum cotinine and IL-6 concentration as well as orthodontically induced inflammatory root resorption （OIIRR）, osteoclast activity （histology）, orthodontic tooth movement velocity （CBCT, within 14 and 28 days of OTM） and relative gene expression of known inflammatory and osteoclast markers were quantified in the dental-periodontal tissue （RT-qPCR）. Animals exposed to nicotine showed significantly heightened serum cotinine and IL-6 levels corresponding to those of regular European smokers. Both the extent of root resorption, osteoclast activity, orthodontic tooth movement and gene expression of inflammatory and osteoclast markers were significantly increased compared to controls with and without OTM under the influence of nicotine. We conclude that apart from increased periodontal bone loss, a progression of dental root resorption and accelerated orthodontic tooth movement are to be anticipated during orthodontic therapy, if nicotine consumption is present. Thus patients should be informed about these risks and the necessity of nicotine abstinence during treatment.

Role of third molars in orthodontics

The role of third molars in the oral cavity has been extensively studied over the years. Literature includes numerous diagnostic and treatment alternatives regarding the third molars. However, an issue that has not been discussed at the same level is their involvement in orthodontic therapy. The aim of this study is to present a review of the contemporary literature regarding the most broadly discussed aspects of the multifactorial role of third molars in orthodontics and which are of general dental interest too.