Anti-nociceptive efficacy of essential oil-based extracts for the management of orofacial pain: a systematic review of available evidence.

OBJECTIVE: Experimental studies have shown that essential oil (EO)-based extracts derived from medicinal plants exhibit antinociceptive activity. The aim of the present systematic review was to assess the anti-nociceptive efficacy of EO-based extracts for the management of orofacial pain (OFP). MATERIALS AND METHODS: To address the focused question "Are EO-based formulations effective for the management of OFP disorders?", indexed databases were searched without time and language restrictions using the preferred reporting items for systematic reviews and meta-analysis guidelines. Risk of bias (ROB) was assessed. RESULTS: Eight studies were included and processed for data extraction. Two studies were clinical (one in adults and one in children) and 6 were performed in rodents. Results from one clinical study showed that inhalation of EO-extracts does not affect subjective toothache scores; and results from the study on children reported that inhalation of lavender oil reduces anxiety and pain during and after tooth extraction. Results from all experimental studies showed that administration of EO-extracts reduces orofacial nociceptive behavior. The ROB was high in 50% and 83.3% of the clinical and experimental studies, respectively. CONCLUSIONS: The anti-nociceptive efficacy of EO-extracts for the management of OFP remains debatable. Further well-designed and power-adjusted randomized clinical trials are needed in this regard.

Influence of mini-screw implant-assisted intrusion on orthodontically induced inflammatory root resorption: a systematic review.

AIM: To systematically review indexed literature related to the influence of mini-screw implant (MSI)-assisted intrusion on orthodontically induced inflammatory root resorption (OIIRR). METHODS: Indexed databases were searched without time and language restrictions using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. The inclusion criteria were: (a) original studies; (b) patients/subjects undergoing MSI-assisted intrusion; and (c) tomographic and/or histological assessment of OIIRR. Letters to the Editor, commentaries, case reports/series, reviews, and studies based on two-dimensional radiographic assessment of OIIRR were excluded. For experimental and clinical studies, the risk of bias assessment was performed using the Systematic Review Centre for Laboratory animal Experimentation risk of bias tool and the Risk of Bias in Non-randomized Studies of Interventions guidelines, respectively. RESULTS: The initial search yielded 453 studies, out of which 6 (3 clinical and 3 on animal-models) were included. The clinical studies were performed on males and females with a mean age ranging between 16.07 and 25.5 years. Duration of the clinical studies ranged from 3.8 to 9 months. The animal studies were performed on mini-pigs, rats, and dogs. The mean age in the studies on rats and mini-pigs was 2.76 and 18 months, respectively. In the study on canine models, mean age was not reported. In all studies, MSI-assisted intrusion was shown to cause OIIRR. Power analysis was performed in one study. All studies had a moderate risk of bias. CONCLUSIONS: MSI-assisted intrusion is a risk factor for OIIRR; however, from a clinical perspective, further well-designed and power-adjusted studies are needed.

Effects of increased surgical trauma on rates of tooth movement and apical root resorption in foxhound dogs.

PURPOSE: To experimentally determine the effects of increased surgical trauma on the rates of tooth movement and apical root resorption. Two surgical techniques for rapid protraction of multi-rooted teeth in foxhound dogs immediately following premolar extraction were compared. METHODS: Split-mouth design to randomly assign two surgical techniques [periodontal ligament distraction (RAP side) and a modified form of dentoalveolar distraction (RAP+ side)] to the maxillary quadrants. First premolars were extracted, and second premolars were protracted 0.5 mm per day for 15 days using a custom made jack-screw distractor. Serial caliper and radiographic measurements were performed to quantify tooth movements and apical root resorption. RESULTS: Both techniques demonstrated significant movement of the crown and apex. The second premolar crowns were protracted significantly more on the RAP+ side (2.9 mm) than on the RAP (1.8 mm) side. The premolars on both sides demonstrated significant tipping (4.3 and 3.9 degrees for the RAP+ and RAP sides, respectively). The distal root apex showed almost twice as much apical root resorption than the mesial root apex, but resorption was limited (<0.16 mm) and not statistically different between sides. CONCLUSIONS: Increased surgical trauma increased the rate and, ultimately, the amount of tooth movement. The heavy forces used to protract the teeth produced statistically, but not clinically, significant apical root resorption on the mesial and distal roots of the maxillary second premolars.

Temporary orthodontic anchorage devices for improving occlusion.

The objective of the study was to provide insight into clinical and laboratory aspects of mini-screw implant (MI) research conducted in the Department of Orthodontics at Baylor College of Dentistry. Excerpts were selected from clinical and laboratory MI research utilizing one type of implant and one consistent placement protocol to illustrate the clinical usage of MI as skeletal anchorage during Class II bimaxillary correction. In addition, a translational animal model was utilized to illustrate possible side-effects of MI placement. Our studies have shown that successful and consistent clinical results are possible with MI use. Although iatrogenic trauma may occur during the placement of MI, a translational research model has provided data used to develop a placement protocol in order to avoid this dilemma. Absolute skeletal anchorage is a reality with MI use and can be used for successful orthodontic outcomes in the correction of Class II bimaxillary protrusion malocclusions to ideal Class I occlusions. Moreover, meticulous care has been shown to be essential with treatment planning and during placement of MI. Significant and extensive damage can occur with poor placement while healing is possible following minor trauma.

The effect of force, timing, and location on bone-to-implant contact of miniscrew implants.

This study was conducted to evaluate the effect of timing and force of loading, as well as implant location, on bone-to-implant contact (BIC) of loaded and control miniscrew implants (MSI). Using seven skeletally mature male beagle dogs, 1-2 years of age, followed over a 110 day period, a randomized split-mouth design compared immediate versus delayed loading, 50 versus 25 g loading, and 25 g loads in the maxilla versus the mandible. Mobility was evaluated using a 0-3 point scale before the MSIs were prepared for histological analysis. Histomorphometric analyses were performed under light microscopy using Metamorph software on undecalcified sections. The percentage BIC was measured at three levels (coronal, middle, and apical) of the MSI. BIC was compared statistically using pairwise Wilcoxon signed-rank tests. Mobility was detected in three of the 56 (5.4 per cent) MSIs. The mobile implants were all unloaded controls and showed no BIC. All remaining stable MSIs showed some BIC. However, variation in BIC was large, ranging from 2.2 to 100 per cent. There were no significant (P > 0.05) differences in BIC associated with timing of force application, amount of force applied, or implant location. There was a tendency for less BIC at the coronal level, but the differences between levels were not statistically significant. Within the limits of this study, it is concluded that the timing and amount of force at loading and location of implant placement do not affect BIC. Moreover, it appears that only limited amounts of osseointegration are necessary to ensure implant stability.

Glass ionomer cements as luting agents for orthodontic brackets.

The objectives of the present study were to (1) assess the shear bond strengths of resin-reinforced glass ionomer Fuji Ortho LC and GC Fuji Ortho cements under differing conditions and (2) compare their bonding performance with that of conventional resin composite bonding systems. A sample of 264 bovine incisors was divided into 22 groups of 12 teeth each and bonded with SPEED central incisor brackets. Enamel surfaces of the teeth in the two experimental groups were conditioned according to the manufacturer's instructions; moreover, groups unconditioned before bonding were also included under both wet and dry conditions. A self-cure composite resin (Phase II) and a light-cure composite resin (Transbond XT) served as controls and were etched with 37% phosphoric acid and bonded in a dry field. After incubation at 37 degrees C for 24 hours and for seven days, the specimens were tested to failure with a shear force in an Instron machine. The Adhesive Remnant Index (ARI) was used to assess the amount of resin left on the enamel surfaces after debonding. Selected specimens were examined using scanning electron microscopy. Statistical analyses included analysis of variance tests, t-tests, and correlation coefficient calculations and showed that no significant difference existed between the glass ionomer cements under wet or dry conditions, provided the enamel was conditioned with 10% polyacrylic acid before bonding. Both glass ionomer cements were thus acceptable for bonding. Transbond XT had the highest mean shear bond strength irrespective of the incubation period. A positive correlation was obtained between the ARI scores and bond strength.

Adhesion of bonded orthodontic attachments to dental amalgam: In vitro study.

Bonding orthodontic attachments to molars is difficult in the presence of extensive buccal amalgam restorations. The purposes of this study were (1) to examine different amalgam surface preparations, (2) to examine properties of adhesive cements to amalgam, (3) to determine the most shear-resistant bonding technique and (4) to discuss whether these shear bond strengths were of adequate magnitude to be of clinical acceptability. The sample consisted of 108 standardized amalgam cylinders divided into 9 groups of 12 based on surface treatment technique and resin type. SPEED brackets (Strite Industries, Cambridge, Ontario) were bonded to amalgam surfaces that were either polished, sandblasted with 50 microm aluminium oxide, or chemically corroded. Adhesives used were Phase II (Reliance Orthodontic Products Inc, Itasca, Ill), Panavia EX (J Morita USA Inc, Tustin, Calif), or C & B Metabond (Parkell, Farmingdale, NY). After thermocycling from 10 degrees C to 50 degrees C 10,000 times, all samples were tested for shear bond strength with the Universal Testing Machine (Instron Corporation, Canton, Mass). The results show significantly higher bond strengths for all of the resin systems when sandblasting of the amalgam surface is used (P <.0001). Only Panavia EX bonded strongly to polished samples, suggesting the presence of a chemical bond. Laboratory acceptable bond strengths to amalgam are possible. The surface characteristics of the amalgam appear to be more influential in the strength of the bond than does the nature of the resin.

Combinations of etchants, composite resins, and bracket systems: an important choice in orthodontic bonding procedures.

The objectives of this investigation were: (1) to compare the shear bond strengths (SBS) of metal, ceramic, and plastic brackets using different concentrations of maleic and phosphoric acid gels and aqueous solutions, and (2) to determine if a relationship exists between the type of acid etchant and the location of resin after debonding. A sample of 210 bovine incisors was divided among three different bracket groups (Victory series metal, Transcend 6000 ceramic, Spirit MB plastic). Prior to bonding, enamel was acid-etched using 37% phosphoric acid (H3PO4) gel and aqueous solution, 10% maleic acid gel and aqueous solution, 10% H3PO4 gel and aqueous solution, or 2% H3PO4 aqueous solution. SBS testing and the adhesive remnant index (ARI) score provided insight into the effects of the bonding process on enamel. Resin tags associated with each etchant type were inspected under scanning electron microscopy (SEM). Statistical analyses (level of significance, p = 0.05) of the data showed significant differences among groups. It was concluded that specific acid-composite-bracket combinations are recommended for use in clinical orthodontic practice in order to achieve efficient bonding.

Optimization of a procedure for rebonding dislodged orthodontic brackets.

The purpose of this study was to compare shear bond strength (SBS) of bonded and rebonded orthodontic brackets following a variety of commonly used conditioning treatments and using both light-cured and self-cured composite resin systems. Brackets debonded during the initial determination of SBS were rebonded after the removal of residual resin from enamel surfaces using five different treatments: (1) Remove residual resin using a tungsten carbide bur, re-etch enamel surface, then bond a new bracket; (2) Remove resin from the base mesh with micro-etching then rebond the same bracket, (3) Remove residual resin from the enamel surface using resin-removing pliers, recondition the enamel with an air-powder polisher, then bond a new bracket; (4) Remove residual resin using a rubber cup and pumice, then bond a new bracket; (5) Remove residual resin using pliers alone, then bond a new bracket. The results revealed that the light-cured system produced higher shear bond strength in the initial bond than the self-cured system (p<0.005). Reconditioning the enamel surfaces using a tungsten carbide bur and acid-etching gave the highest SBS (difference 5.8 MPa; p<0.01) and clinically favorable fracture characteristics. The data suggest that the optimal procedure for rebonding dislodged orthodontic brackets is to resurface the enamel using a tungsten carbide bur, acid-etch the enamel, and use a new or re-use an old bracket after microetching.

Terminology: semantics of postorthodontic treatment changes in the dentition.

Correct terminology eliminates confusion in communication between clinicians, as well as between clinician and patient. Long-term stability seems to be an elusive goal, because the terminology in this respect eludes to the various changes occurring in the posttreatment dentition. However, a stable orthodontic result can be achieved when the physiologic changes that naturally occur in the dentition are considered as part of the long-term result. Standardization of terminology is therefore important.

A longitudinal evaluation of extraction versus nonextraction treatment with special reference to the posttreatment irregularity of the lower incisors.

A tendency exists in contemporary orthodontics to pursue a completely non-extraction philosophy. Moreover, it has been shown that the extraction versus non-extraction debate is still with us. Controversy exists as to which treatment decision will eventually lead to orthodontic stability. It is thus imperative to conduct investigations on long-term changes of the dentition in both treatment regimens. The present study serves as an example of such a longitudinal study. A random sample, inclusive of both extraction and non-extraction treatments, was examined with respect to long-term stability and an assessment was made as to whether one treatment option favors success over the other. It was concluded that the correct initial treatment choice will not only lead to correction of the malocclusion, but will also ensure clinically acceptable stability with no significant differences between extraction and non-extraction treatments.

Postretention mandibular incisor stability after premolar serial extractions.

The purpose of this study was to evaluate the mandibular incisor alignment in serial extraction cases, using the longitudinal dental cast records of the Burlington Growth Center as a control sample. Various parameters were investigated and the statistical differences determined between the treated and untreated groups. The results were also compared with data from serial extraction groups that subsequently had orthodontic treatment. Untreated subjects and subjects treated only with serial extractions showed similar longitudinal changes. However, the extraction group that also received orthodontic treatment appeared to show more lower incisor crowding long-term. No predictors for stability of clinical significance could be determined. Mechanotherapy influences the craniofacial and dentoalveolar dimensions, which appear to cause more long-term lower incisor crowding.

The effect of various storage methods and media on shear-bond strengths of dental composite resin to bovine dentine.

A variety of media and methods have been used to store teeth used in bond-strength studies of resin restorative materials to dentine. This study examined the effect of 2 months of storage using 11 different methods and media on the shear-bond strength of Z100 resin composite to bovine dentine mediated by Scotchbond Multi Purpose adhesive. Freshly harvested teeth were used as controls. The results showed that 7 of the l1 storage methods or media were similar in shear-bond strengths and bond-failure characteristics. Four of the 11 methods (irradiation, or storage in thymol, methanol, and glutaraldehyde) resulted in significantly lower shear-bond strengths and atypical shear-bond failure, indicating that these are the least desirable methods of tooth storage for studies of this type. This study has further shown that if insufficient numbers of fresh teeth are available for studies of shear-bond strength, then freezing is the preferred method of storage for the registration of high shear-bond strengths. It is also apparent that further investigations are needed to examine what post mortem changes occur in dentine, whether these changes are modified by various storage conditions, and whether they have any significant effect on bonding of resin composites.

Radiographic localization of mandibular anesthesia landmarks.

The objective of this study was to assess whether bony landmarks used for the standard inferior alveolar nerve block can be used to accurately determine the position of the mandibular foramen and whether panoramic radiographs are appropriate for this purpose. A total of 11 landmarks from 79 panoramic radiographs and 70 corresponding cases of oblique (45-degree) cephalometric radiographs were examined. Ten measurements of the distance from each landmark to the mandibular foramen, as well as 6 ratios from these distances, were calculated from all radiographs. The results showed that the position of the mandibular foramen was highly individualistic and not consistently related to traditional clinical landmarks. Panoramic radiographs were as good as oblique cephalometric radiographs for the locating of the mandibular foramen. No age or gender correlations were found. It was concluded that the mandibular foramen can be localized in panoramic radiographs but that its relation to bony landmarks is highly variable.

The relationship between bond strength and orthodontic bracket base surface area with conventional and microetched foil-mesh bases.

The aim of this study was to test the effects on the shear bond strength by sandblasting bracket base surfaces, reducing base surface area, and etching enamel with various acid types. Four different base sizes, used as either standard (untreated), sandblasted or microetched were bonded with Phase II resin (Reliance Orthodontic Products, Inc.) in four groups of 12 bovine enamel specimens after enamel etching with phosphoric acid gel (37%), 37% phosphoric acid aqueous solution, 10% maleic acid gel, or 10% maleic acid aqueous solution. Storage of samples was for 7 days in distilled water at room temperature before shear bond testing with an Instron universal testing machine with a crosshead speed of 0.5 mm/min. Statistical analyses included the analysis of variance, the Student t test, and the Chi-square test at p < 0.05. An increase in shear bond strength was associated with sandblasting and microetching of foil-mesh bases for all base sizes (p < 0.05). No statistically significant difference in shear bond strength existed between the three larger base sizes, which indicated that shear bond strength is independent of surface area between 6.82 and 12.35 mm2. A reduction in bond strength was associated with the reduction of base surface area from 6.82 to 2.38 mm2 (p < 0.05). There appears to be no need to increase base surface area beyond 6.82 mm2. Aqueous maleic acid (10%) etching of the enamel was associated with the highest shear bond strength, with no statistically significant difference between the other three acids used.

Dimensional differences in the craniofacial morphologies of groups with deep and shallow mandibular antegonial notching.

Certain craniofacial characteristics were identified on the lateral cephalograms of 40 untreated subjects with shallow mandibular antegonial notches and 40 subjects with deep notches. Subjects with shallow notches demonstrated more on the morphological characteristics usually associated with horizontal mandibular growth patterns than did subjects with deep notches, and their mandibles were positioned more protrusively. In general, the mandibles of the shallow notch subjects proved to be longer than mandibles of the deep notch subjects. On average, mandibles with deep notches showed greater gonial angles, deeper posterior ramus notch depths, and larger occlusal plane inclinations. The total anterior facial height of shallow notch subjects was much smaller than that of the deep notch subjects. The maxillae in deep notch subjects were more retrusive in relation to the cranial base when compared with the shallow notch subjects. A discriminant analysis was used to determine which combinations of variables were most consistently related to either deep or shallow mandibular antegonial notches. Eighty percent (80%) of the cases were classified correctly as deep or shallow notch cases by means of this discriminant function.