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Introduction: Despite the serious health implications associated with obstructive sleep apnoea, the condition remains under-diagnosed. This study aims to evaluate the awareness of the condition amongst the Australian community. Methods: A total of 2016 respondents recruited from a web-based panel completed an online questionnaire which assessed awareness and experience of obstructive sleep apnoea and sleep-disordered breathing. The association between the level of awareness and various socio-demographic variables was analysed using uni- and multivariate analyses. Results: The results of the questionnaire indicated that 50% and 70% of participants were unaware of adult and paediatric obstructive sleep apnoea. Socio-demographic variables including age, annual household income and education level significantly influenced a participant’s level of awareness. Approximately 8.3% of the participants had previously been diagnosed with obstructive sleep apnoea. However, 65% of participants exhibiting symptoms of daytime sleepiness had not sought health care. Paediatric sleep apnoea had been previously diagnosed in 7.1% of children residing in participant’s households but 49% of children with regular snoring had not been medically evaluated. Conclusion: A deficiency exists in the awareness of sleep apnoea amongst the Australian general public. This is reflected in the discrepancy between the number of participants exhibiting potential symptoms and those who sought medical advice.

Objective To compare the skeletal, dentoalveolar and buccal bone thickness of tooth–bone-borne (Hybrid-H) and tooth-borne (TB) maxillary expanders used for rapid maxillary expansion (RME) in early and late adolescents and for surgically-assisted RME (SARME) in young adults. Materials and methods: This two-centre clinical study included initial and 6 months post-retention CBCT records of 60 patients (27 males, 33 females; mean age 15.7 ± 3.75 years). The cohort was divided into two groups according to the expander type (H or TB) and subdivided into a further three groups determined by cervical vertebrae maturation stages: early adolescents (EA), late adolescents (LA), and young adults (A). EA and LA patients underwent RME and young adults received a SARME. Results: The hybrid-designed appliance increased the internal skeletal maxillary width and nasal width more than the TB-designed appliance anteriorly in EA and posteriorly in SARME young adults. The TB expanders tipped and expanded the first premolars more than the Hybrid SARME expanders in young adults and caused a greater reduction in buccal alveolar bone thickness at the level of the first premolars and molars at the three growth stages. Conclusion The hybrid expanders, with relatively greater skeletal and nasal widening potential and fewer dentoalveolar side effects, were a favourable alternative to tooth-borne expanders for RME in the early and late adolescents, and for SARME in young adults.

The University of Sydney’s Discipline of Orthodontics has been actively pursuing research in the areas of root resorption, sleep apnea, magnets in orthodontics, implants, acceleration of orthodontic tooth movement (OTM), and remote monitoring (RM). Our research has shed light on many specific factors that influence orthodontically induced inflammatory root resorption (OIIRR). We also explored the effects of some of the most discussed acceleration interventions on OTM and OIIRR, such as vibration, micro-osteoperforations, piezocision, low-level laser therapy, light emitting diode, light amplification by stimulated emission of radiation, and pharmacological substances. Further, we have researched into maximizing orthopedic treatment outcomes of maxillary deficient children with use of intraoral force application with utilization of miniscrew-assisted rapid palatal expander. We are currently trialing use of RM to facilitate orthodontic services in the public dental clinics.

Summary Objective To assess three rapid maxillary expansion (RME) appliances in nasal ventilation. Trial design Three-arm parallel randomized clinical trial. Methods Sixty-six growing subjects (10–16 years old) needing RME as part of their orthodontic treatment were randomly allocated (1:1:1 ratio) to three groups of 22 patients receiving Hyrax (H), Hybrid-Hyrax (HH), or Keles keyless expander (K). The primary outcome of nasal ventilation (pressure and velocity) and secondary outcomes (skeletal, dental, soft tissue, and nasal obstruction changes) were blindly assessed on the initial (T0) and final (T1, 6 months at appliance removal) cone-beam computed tomography (CBCT) data by applying computational fluid dynamics (CFD) method. Differences across groups were assessed with crude and adjusted for baseline values and confounders (gender, age, skeletal maturation, expansion amount, mucosal/adenoid hypertrophy, nasal septum deviation) regression models with alpha = 5%. Results Fifty-four patients were analysed (19H, 21HH, 14K). RME reduced both nasal pressure (H: −45.8%, HH: −75.5%, K: −63.2%) and velocity (H: −30%, HH: −58.5%, K: −35%) accompanied with nasal obstruction resolution (H: 26%, HH: 62%, K: 50%). Regressions accounting for baseline severity indicated HH expander performing better in terms of post-expansion maximum velocity (P = 0.03) and nasal obstruction resolution (P = 0.04), which was robust to confounders. Mucosal/adenoid hypertrophy and nasal septum deviation changes were variable, minimal, and similar across groups. The HH resulted in significantly greater increase in the nasal cross-sectional area (62.3%), anterior (14.6%), and posterior (10.5%) nasal widths. Nasal obstruction resolution was more probable among younger (P = 0.04), skeletally immature (P = 0.03), and male patients (P = 0.02) without pre-treatment mucosal hypertrophy (P = 0.04), while HH was associated with marginal greater probability for obstruction resolution. Conclusions RME resulted in improvement of nasal skeletal parameters and simulated ventilation with the former being in favour of the HH and the latter not showing significant differences among the three appliances. Limitation Attrition in the K group due to blocked activation rods possibly leading to limited sample to identify any existing group differences. Harms Replacement of blocked Keles expanders for finalizing treatment. Protocol The protocol was not published before the trial commencement. Registration Australian and New Zealand Clinical Trial Registry; ACTRN12617001136392.

STUDY OBJECTIVES: To evaluate facial 3-dimensional (3D) stereophotogrammetry’s effectiveness as a screening tool for pediatric obstructive sleep apnea (OSA) when used by dental specialists. METHODS: One hundred forty-four participants aged 2–17 years, including children fully diagnosed with pediatric OSA through nocturnal polysomnography or at high-risk or low-risk of pediatric OSA, participated in this study. 3D stereophotogrammetry, Craniofacial Index, and Pediatric Sleep Questionnaire were obtained from all participants. Ten dental specialists with interest in pediatric sleep breathing disorders classified OSA severity twice, once based only on 3D stereophotogrammetry and then based on 3D stereophotogrammetry, Craniofacial Index, and Pediatric Sleep Questionnaire. Intrarater and interrater reliability and diagnostic accuracy of pediatric OSA classification were calculated. A cluster analysis was performed to identify potential homogeneous pediatric OSA groups based on their craniofacial features classified through the Craniofacial Index . RESULTS: Intrarater and interrater agreement suggested a poor reproducibility when only 3D facial stereophotogrammetry was used and when all tools were assessed simultaneously. Sensitivity and specificity varied among clinicians, indicating a low screening ability for both 3D facial stereophotogrammetry, ranging from 0.36–0.90 and 0.10–0.70 and all tools ranging from 0.53–1.0 and 0.01–0.49, respectively. A high arched palate and reversed or increased overjet contributed to explaining how participating dental clinicians classified pediatric OSA. CONCLUSIONS: 3D stereophotogrammetry-based facial analysis does not seem predictive for pediatric OSA screening, alone or combined with the Pediatric Sleep Questionnaire and Craniofacial Index when used by dental specialists interested in sleep-disordered breathing. Some craniofacial traits, more specifically significant sagittal overjet discrepancies and an arched palate, seem to influence participating dental specialists’ classification. CITATION: Fernandes Fagundes NC, Carlyle T, Dalci O, et al. Use of facial stereophotogrammetry as a screening tool for pediatric obstructive sleep apnea by dental specialists. J Clin Sleep Med. 2022;18(1):57–66.

Fluoride has a major role in strengthening the structure of enamel against acids. Despite differences between caries and root resorption processes, both events inherently involve acidic dissolution of dental tissues. The aim of the present study was to investigate the effects of water fluoridation levels on the surface roughness of root cementum and resorption craters. The findings provided more insight into the influence of fluoride on the surfaces of intact cementum surface and resorption craters.Twenty-eight orthodontic patients were recruited from two cities in Turkey, with high (≥ 2 ppm) and low (≤ 0.05 ppm) water fluoridation. These patients needed bilateral maxillary first premolar extraction as part of their orthodontic treatment and were allocated into two study groups (n = 14 in each group) based on water fluoridation exposure level: the high-fluoride group (HF) and low-fluoride group (LF). 150 g of buccal tipping forces was applied to all maxillary first premolar teeth for 12 weeks with a beta-titanium spring which was reactivated every 4 weeks. All maxillary premolars were removed at the end of the experiment for surface roughness assessment using three-dimensional confocal microscopy and the associated software. The buccal root surface and the largest buccal resorption crater were investigated.Resorption craters were significantly rougher in LF group compared to HF group (p = 0.002). Craters were rougher than the intact root surfaces (p = 0.000). Cervical and apical regions were significantly rougher than the middle region (p = 0.000 and p = 0.024, respectively).Higher water fluoridation level of ≥ 2 ppm resulted in significantly smoother root resorption craters than low water fluoridation level of ≤ 0.05 ppm when the teeth were subjected to 150 g of buccal tipping force. Fluoride seems to have a protective role at the interface of root resorption, and further mineral or histological studies may shed light on the exact protective process against root resorption.

Summary Aim To compare root resorption (RR) after rapid maxillary expansion (RME) and slow maxillary expansion (SME) through micro-computed tomography (micro-CT). Subjects and methods Twenty-six subjects who required maxillary expansion and bilateral upper first premolar extraction were randomly assigned to RME (n = 13, mean age: 13.25 ± 0.88 years) or SME (n = 13, mean age: 13.53±1.28 years) group. A hyrax-type acrylic bonded expansion appliance was used. The Hyrax screw was activated ¼ turn twice a day for 20 days in the RME group and ¼ turn every second day for 80 days in the SME group. One randomly selected upper first premolar was extracted in each patient after active expansion. The appliance was left in situ for a 24-week retention period then the contralateral upper first premolar was extracted. Extracted teeth were scanned with micro-CT and the volume of the resorption craters was analysed with a specialized software. Transversal skeletal and dental widths were measured on posteroanterior radiographs taken before and after expansion and retention periods. Results The resorption craters were concentrated mostly on the buccal surface and middle level in all samples. The total RR in the RME group was less post-expansion (P ≤ 0.05) and more post-retention (P > 0.05) than the SME group. During retention, there was a significant decrease in the total RR in the SME group (P > 0.05) and an increase in the RME group. Both RME and SME groups displayed a similar increase in skeletal transverse dimensions, but inter-molar width increased significantly more in the SME group during the whole experimental period. Conclusion RME does not have an advantage over SME in terms of skeletal expansion and the amount of RR when a retention period of six months is followed.

Summary Objective To assess upper airway volume changes after rapid maxillary expansion (RME) with three different expanders. Trial design Three-arm parallel randomized clinical trial. Methods Sixty-six patients, 10–16 years old, in permanent dentition, with maxillary transverse deficiency were recruited and assigned with block randomization (1:1:1 ratio) and allocation concealment to three groups of 22 patients each (Hyrax, Hybrid-Hyrax, and Keles keyless expander). The primary outcome (overall upper airway volume change) and secondary outcomes (volume changes in the nasal cavity, nasopharynx, oropharynx, and hypopharynx) were blindly assessed on the initial (T0) and final (T1, 6 months at appliance removal) cone beam computed tomography. Differences across groups were assessed with crude or adjusted for confounders (gender, age, growth stage, skeletal pattern, baseline airway volume, and amount of expansion) linear regression models. Results Fifty-one patients were analysed (19, 19, and 13 in the Hyrax, Hybrid-Hyrax, and Keles groups). Maxillary expansion resulted in considerable increases in total airway volume in the Hybrid-Hyrax group (+5902.1 mm3) and less in the Hyrax group (+2537.9 mm3) or the Keles group (+3001.4 mm3). However, treatment-induced changes for the primary and all secondary outcomes were of small magnitude and no significant difference was seen among the three expanderes in the total airway volume in either crude or adjusted analyses (P > 0.05 in all instances). Finally, among pre-peak patients (CVM 1–3), the Hybrid-Hyrax expander was associated with significantly greater increases in total airway volume compared to the Hyrax expander (P = 0.02). Conclusions RME resulted in relatively small increases in total upper airway volume and its separate compartments, with mostly no statistically significant differences across the Hyrax, Hybrid-Hyrax, and Keles groups. Limitations Significantly greater attrition was found in the Keles group due to appliance failure. The current trial might possibly be under-powered to detect differences between groups, if such exist. Harms Keles expanders blocked during activations and required substitution for completion of treatment. Protocol The protocol was not published before trial commencement. Registration Australian and New Zealand Clinical Trial Registry (ACTRN12617001136392).

INTRODUCTION This study aimed to retrospectively evaluate the dentoskeletal effects of clear aligners (Invisalign) vs miniplate-supported posterior intrusion (MSPI) and identify factors associated with posttreatment overbite in adults with anterior open bite. METHODS Twenty-nine patients treated with Invisalign and 24 with MSPI combined with full-fixed orthodontic appliances were included from 5 orthodontic practices. Pretreatment and posttreatment lateral cephalometric measurements were included as outcomes. Comparisons across groups and identification of final overbite predictors were assessed with regression modeling and machine learning techniques. RESULTS MSPI induced significantly greater maxillary molar intrusion (1.5 mm; 95% confidence interval [CI], 0.83-2.17; P

Introduction This split-mouth trial aimed to investigate the effect of low-level laser therapy (LLLT) on the amount of maxillary canine distalization when applied every 4 weeks over 12 weeks. Methods Twenty-two adolescents and young adults (15 female, 7 male; aged 13-25 years; n = 22) requiring bilateral maxillary first premolar extractions were recruited. After extractions and leveling-alignment, canines were retracted using closed-coil nickel-titanium springs delivering 150 g of force. LLLT was applied to 8 intraoral points on the buccal and palatal sides around the canine root for 10 seconds per point, on day 0, 28, and 56 with the control side receiving sham application. Alginate impressions were taken every 4 weeks on day 0, 28, 56, and 84. The amount of tooth movement, anchorage loss, and canine rotation were measured digitally. Randomization was generated using www.randomisation.com and allocation concealment through sequentially numbered, opaque, sealed envelopes. Participants, operator, and statistic assessor were blinded. Linear regression modeling accounting for clustering within each patient was used to identify differences between LLLT and control sides. Results Twenty-one patients completed the study. The total amount of tooth movement was similar in the LLLT (2.55 ± 0.73 mm) and control group (2.30 ± 0.86 mm), whereas 0.25 mm (95% confidence interval, –0.21, 0.71 mm) of difference was insignificant (P = 0.27). No significant differences were found for anchorage loss (P = 0.22) or canine rotation (P = 0.25). No harms were reported. Conclusions Application of LLLT every 4 weeks did not result in differences in the amount of tooth movement, anchorage loss, and canine rotation during extraction space closure.

Introduction The aim of this study was to evaluate the short- and long-term effects of hybrid-Hyrax, Alt-RAMEC and applied, miniscrew reinforced, heavy intermaxillary elastics on a modified lingual arch in growing skeletal Class III patients. Methods Fifteen subjects (seven male, eight female) were included, with an average age of 12.52 ± 0.94 years, of cervical vertebrae maturation (CVM) stage CS2-CS4 and skeletal Class III malocclusions due to a retrognathic maxilla. Nine weeks of Alt-RAMEC were followed by eight to nine weeks of maxillary protraction with heavy 400 gm Class III elastics worn 24 h/day. Treatment was finalised with orthodontic fixed appliances. Cone beam computed tomographic (CBCT) scans were taken initially (T1), at the end of maxillary protraction (T2) and four years after active orthopaedic treatment (T3). Cephalometric measurements were performed on reconstructed lateral cephalograms and the differences between time intervals were calculated using an analysis of variance (ANOVA). Results A positive overjet was achieved in all but one subject. From T1 to T2, A point advanced 3.12 ± 3.42 mm and from T2 to T3 advanced a further 2.21 ± 3.49 mm. Significant initial increases in SNA of 1.05° ± 1.10° (p = 0.004), ANB of 2.71° ± 1.01° (p = 0.00), Wits of 4.49 ± 2.21 mm (p = 0.00) and overjet of 4.90 ± 1.66 mm (p = 0.00) were accomplished and maintained without significant changes in the vertical dimension. Upper and lower incisor inclinations were not affected by the protraction protocol but significantly increased (U1-PP: 8.39° ± 5.59°) between T2 and T3. SNB decreased initially by 1.67° ± 1.34° (p = 0.00) but relapsed due to residual mandibular growth and a counterclockwise rotation of the mandibular plane. Conclusion The hybrid-Hyrax Alt-RAMEC combined with miniscrew reinforced heavy Class III elastics resulted in a favourable and stable Class III correction.

Introduction Anchorage is crucial in controlling tooth movement during orthodontic treatment. Different designs have been introduced to increase the stability of miniscrews. A new miniscrew, The Sydney Mini Screw (SMS), with a hollow chamber and lateral port holes, has been developed to allow the diffusion of an injectable bone graft substitute (iBGS) into cancellous bone. The aim of this study was to analyse the optimum iBGS application with ideal chemo-mechanical properties to be used in conjunction with the novel SMS. Method A composite calcium sulphate and calcium phosphate bone graft substitute was examined. The effects of powder particle size, and the powder-to-liquid ratio on the injectability of the iBGS through the SMS were investigated. The viscosity, injectability, and mechanical properties of the new composite mixtures were assessed using rheology and universal compression measurements. Results The results showed that the optimised injectable formulation of the bone cement was acquired with the concentration of 2.5 g/ml. This concentration was readily injectable through the SMS, and its setting time was within 2–3 minutes, which is favourable for clinicians. In addition, the resulting structure fractured at 80 kPa compression stress. Conclusion The result of this study identified the specific particle size and powder-to-liquid ratio of the iBGS that can be used in conjunction with the new SMS to enhance the primary stability of orthodontic miniscrew applications.

Background With minimal manufacturer information, a variety of ‘generic’ orthodontic brackets are available online from overseas distributors. The present study investigated the metal composition of generic orthodontic brackets compared with two well-known ‘proprietary’ brands. Materials and methods Ranging in price from AU$2.99 to $65, five sets of different generic brackets were obtained directly from China via eBay (G1, G2…G5). Proprietary brackets were obtained from American Orthodontics (P1) and Rocky Mountain Orthodontics (P2). The 11, 12, 13 and 14 brackets from each set were liquefied in an acid solution and subjected to trace element analysis using inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma optical emission spectroscopy (ICP-OES) with respect to nickel, chromium, iron, copper, molybdenum, manganese, cadmium, mercury, arsenic and lead. Statistical analysis investigated the compositional consistency within and between each brand. Results The composition of P1 and P2 agreed with the manufacturer’s data. The generic groups typically had low molybdenum and higher copper content and approximated either 17-4 or AISI304 stainless steels or a combination of both. No relationship between brand and consistency of manufacture could be identified. The cheapest bracket contained lead. Conclusions Generic and proprietary brackets showed differences in their metal composition that may have biocompatibility implications.

Background The use of Twin Block therapy is a well-accepted functional treatment option for the correction of a Class II malocclusion. In addition to skeletal and dental changes, its use may also promote changes in airway structure and dimension, including the size of the posterior airway space (PAS). This may be of importance in reducing the risk of developing obstructive sleep apnoea syndrome (OSAS). Materials and methods Sixteen (16) subjects (eight females and eight males) underwent treatment of a Class II division 1 malocclusion via the use of a Sydney Bonded Twin Block (SBTB) appliance followed by full fixed orthodontic therapy (FFOA). Pretreatment (T1), post-twin block (T2) and post-fixed appliance (T3) lateral cephalograms were taken and skeletal and soft tissue landmarks were hand traced. A pairwise comparison was used to assess whether there were any significant differences in the cephalometric variables between each phase of treatment (T1, T2, T3). Results The skeletal variables SNB and ANB revealed a significant change between T1-T2 (p < 0.01). The sagittal size of the nasopharynx (RPAS) also recorded a significant change between T1-T3 (p < 0.05). There was no significant change in the PAS at any stage of treatment. There was an average reduction in the ANB angle of 2° (p < 0.01) between T1-T3. Conclusions There was no significant change in the size of the PAS following SBTB treatment. However, an increase in RPAS was recorded following SBTB treatment which continued to improve during FFOA therapy.

Objectives The purpose of this study was to qualitatively and quantitatively analyse the effect of glucosamine sulfate and chondroitin sulfate supplements on condylar remodelling in conjunction with bite-jumping functional appliance therapy in rats. Materials and methods The study involved 140 three-week-old, female rats which were divided into a control group (CG), a supplementation group (SG), a functional appliance (bite-jumping) group (FG) and a bite-jumping appliance and supplement recipient group (FSG). The animals were sacrificed at Day 0, Day 7 and at Day 21 after appliance placement, as well as seven days following appliance removal. The condylar head from each animal was blindly scanned using micro-computed tomography (μCT). Qualitative evaluation and volumetric measurements of the condyles, including total condylar volume (TCoV), posterior condylar volume (PCoV), total cartilage volume (TCaV) and posterior cartilage volume (PCaV), were undertaken using VGStudioMax software. Results One hundred and thirty-five rats were analysed, some of which responded to the intervention with a protruded bite (Class III response) while others responded with a retruded bite (Class II response). The TCoV and PCoV of the CG decreased during the experimental period. The functional appliance alone and the combination of the functional appliance with the supplement had a significant effect on TCoV and PCoV over the intervention period (p < 0.01), peaking at Day 7. There was no statistically significant difference in TCaV between animals that experienced Class II and Class III bite responses at Days 21 and 28 (p > 0.05). However, at Day 21, the PCaV increased significantly in those animals which displayed a Class II bite response (p < 0.05). The shape of the condyles in FG and FSG varied significantly from that of the condyles in CG and SG. Conclusion Supplement therapy was found to enhance the normal biological response to functional appliance therapy in a rat model, particularly after the functional appliance was removed. Further research using an immuno-histochemical analysis of a modified bite-jumping appliance and improved food delivery is recommended.

Background Hormonal and enzymatic factors may render certain individuals more susceptible to orthodontically induced inflammatory root resorption (OIIRR). The objectives of this study are (1) to identify biochemical key markers in blood and saliva that may be correlated to the trend of extensive OIIRR and (2) to utilise these markers to predict a susceptible patient-receiving orthodontic treatment. Methods Nine patients (mean age 23 + 2.9 years) who had moderate to severe OIIRR that assessed via orthopantomograms and met the inclusion criteria were classified as the root resorption group (RRG). Blood chemistry was evaluated using the collection of fasting blood and unstimulated saliva samples. Multiplex enzyme-linked immunosorbent assay (ELISA) arrays were used to screen blood and saliva samples for human cytokines, chemokines and several key enzymes that may play a role in root resorption following orthodontic force application. Biochemical findings from 16 matching subjects were used as the control (CG) for comparative measurements. Results Patients with moderate to severe OIIRR showed a significant increase in salivary cytokines including interleukin (IL) 7, IL-10, IL-12p70 and interferon-gamma (IFN-γ) level as well as a significant decrease in IL-4 level. Osteocalcin and procollagen type I N-terminal peptide (P1NP) appeared to be the only blood factors that showed a significant difference, more in the CG than the RRG. Conclusions Saliva might be a more valuable way of measuring changes in cytokine expression than blood secondary to orthodontic treatment. Although the increased expression of pro-inflammatory and anti-inflammatory cytokines may be determinants in the development of moderate to severe OIIRR, cytokine expression may be affected by several potential inflammations in another part of the body. Future research could investigate the cause/effect relationship of different cytokines, in a larger group of patients and at different time intervals, using digital subtraction radiography techniques and microfluidic biosensors.

Objectives To assess the potential effects of casein phosphopeptides (CPPs) on orthodontically induced iatrogenic root resorption (OIIRR) and orthodontic teeth movement. Materials and methods Forty Wistar rats (aged 11 weeks) were randomly divided into experimental group (EG; n = 20) that received a diet supplemented with CPP and control group (CG; n = 20) devoid of diet supplement. A 150 g force was applied using nickel titanium (NiTi) coil that was bonded on maxillary incisors and extended unilaterally to a maxillary first molar. At Day 28, animals in both groups were euthanized. Volumetric assessment of root resorption craters and linear measurement of maxillary first molars movement were blindly examined using a micro-computed tomography scan. Results Nine rats were excluded from the experiment due to loss during general anesthesia or appliances' failure. Intra-operator reproducibility was high in both volumetric and linear measurements, 92.8 per cent and 98.5-97.6 per cent, respectively. The results reveal that dietary CPP has statistically insignificant effect on the overall OIIRR and orthodontic movement. Conclusions CPP seems to have statistically insignificant effect on the volume of OIIRR and orthodontic movement in rats. A long-term study with larger sample size using a different concentration of CPP is required to clarify the dentoalveolar effect of CPP.

Background Orthodontically-induced inflammatory root resorption (OIIRR) is an unwelcome side effect of orthodontic treatment. Mechanical vibration has been suggested as a preventative measure but evidence is limited. The aim of this study was to investigate whether whole body mechanical vibration has a positive influence on OIIRR. Material and methods Thirty-six 10-week-old Wistar rats were divided into three groups, which received either 30 Hz vibration, 60 Hz vibration or no vibration to serve as a control group. A heavy mesial force of 100 g was applied to the left maxillary first molar using nickel-titanium closed-coil springs. The right maxillary first molar served as an internal control. The vibration groups received 30 Hz or 60 Hz of whole body vibration for 10 minutes per day for 14 days. A volumetric analysis of the extent of root resorption on the mesial-buccal root of the first maxillary molar was examined using micro-computed tomography. Results When compared with the control group, the animals that received 30 Hz (p = 0.21) and 60 Hz (p = 0.16) of mechanical vibration did not show a statistically significant reduction in OIIRR. The results did not show a statistically significant difference in the extent of OIIRR between 30 Hz and 60 Hz vibration groups (p = 0.78). Conclusion Mechanical vibration at 30 Hz and 60 Hz, when applied in an experimental model of whole body vibration, showed no significant effect on either physiological root resorption or OIIRR in rat molars loaded by a heavy orthodontic force.

Almuzian, Mohammed/0000-0002-1696-6649 WOS: 000468066900001 PubMed: 31084610 BackgroundBiomarkers can aid in detecting and preventing clinical disease through the recognition of change in biological samples. The objective of this case-control study was to further the knowledge on the use of big toenail and hair samples as biomarkers for fluoride exposure.MethodsA total of 48 participants from an endemic (IC) and a non-endemic (SC) fluorosis region were included. Big toenail and hair samples were collected from each participant and the fluoride concentration was determined. The results of 42 participants were reported: 21 participants (11 males and 10 females, mean age 15.66+2.61years) from IC and 21 participants (11 males and 10 females, mean age 15.06+0.79years) from SC.ResultsThe mean fluoride concentration of big toenail (2.340.26mg/kg) and hair (0.24 +/- 0.04mg/kg) in the endemic region was significantly higher than the mean fluoride concentration of big toenail (0.98 +/- 0.08mg/kg) and hair (0.14 +/- 0.02mg/kg) in the non-endemic region (p

Aim: The primary aim of this study was to assess the differences in the upper airway morphology between responders and non-responders to mandibular advancement splint (MAS) treatment in obstructive sleep apnoea (OSA) management. The secondary aim was to assess the correlation between the minimum cross-sectional area of the upper airway and the anatomical structures (i.e. mandibular external length, maxillary length, soft palate length, area of the tongue, maxillomandibular enclosure size, and anatomical balance ratio) surrounding the upper airway. The third aim was to assess the differences in the overall skeletal configuration between responders and non-responders to MAS treatment.Methods: Data from 64 patients (23 females and 41 males) diagnosed with OSA by polysomnography (PSG) at baseline and provided with an adjustable MAS were analysed. All patients had NewTom3G cone beam computed tomography (CBCT) scans, performed in the supine position, at baseline. After acclimatization to MAS, follow-up PSG tests were performed to assess the apnoea–hypopnea index (AHI) with the MAS in situ. Responders were defined by a post-treatment AHI less than 10/hour and at least 50 per cent reduction in AHI, and non-responders by a post-treatment AHI at least 10/hour or less than 50 per cent reduction in AHI. Several upper airway and anatomical variables surrounding the upper airway based on CBCT images were measured to determine the differences between responders and non-responders to MAS.Results: There were 36 responders (AHI = 24.8 ± 11.9 at baseline) and 28 non-responders (AHI = 31.2 ± 20.3 at baseline) to MAS. There were no significant differences in the upper airway morphology between responders and non-responders (P = 0.17–0.93) or in the anatomical structure surrounding the upper airway (P = 0.24–0.58).Conclusion: Within the limitations of this study, it can be concluded that there are no significant differences in upper airway morphology and in anatomical structures surrounding the upper airway between responders and non-responders to MAS treatment. These findings suggest that the craniofacial anatomical structures analyzed in this study cannot explain the response to MAS treatment.

Purpose Surgically assisted rapid maxillary expansion (SARME) is required in non-growing patients when maturity or resistance precludes desired sutural separation by noninvasive techniques. The aim of this review was to determine what volumetric changes occur in the upper airway spaces after SARME in adults. Materials and Methods A systematic review was performed with data assessed for suitability of meta-analysis. The primary outcome measurement of volumetric changes in an upper airway space was sought in non-growing patients undergoing SARME. Electronic database searches were performed for published literature in Medline (by Ovid), Pre-Medline, Old Medline, Embase, and the Cochrane Central Register of Controlled Trials (CENTRAL) spanning all available years to August 1, 2015. Unpublished literature was searched electronically through ClinicalTrials.gov and the National Research Register. Additional hand searching of reference lists of relevant articles, grey searching, and expert correspondence was conducted for any additional studies. Two authors independently screened search results, extracted data, and assessed the risk of bias of included studies. Results Twenty-one studies were located by initial screening; 10 were excluded after full-text review, leaving 11 studies eligible that met all inclusion criteria for this systematic review. In total, 204 treated patients (mean age, 18 to 31 yr) were included in the qualitative synthesis. Ten studies evaluated nasal cavity volume, 2 evaluated palatal volume, and 1 evaluated oropharyngeal volume. Appliances used included tooth-borne hyrax and transpalatal distractor devices. Conclusions SARME was found to produce substantial short-term volume increases in the nasal cavity in non-growing patients that were maintained for at least 63 months. Evidence weakly suggested no effect on oropharyngeal volume. However, most studies were evaluated as having a high risk of bias. The effect of such volume changes on respiratory function still needs to be determined; thus, SARME cannot be recommended for respiratory purposes.

Objectives: To establish the effectiveness of Alternate Rapid Maxillary Expansion and Constriction combined with Protraction Facial Mask (Alt-RAMEC/PFM) approach in treating Class III growing patients compared with PFM combined with conventional Rapid Maxillary Expansion (RME/PFM). Search sources: Unrestricted search in five electronic databases and manual searching were undertaken up to February 2018. Data selection: Randomised clinical trials (RCTs) evaluating the effectiveness of Alt-RAMEC/PFM were selected. Data extraction: Screening of references, data extraction and assessment of bias risk were evaluated independently by two reviewers. Results: Five RCTs comparing the Alt-RAMEC/PFM with RME/PFM met the inclusion criteria. Small but statistically significant mean differences favouring Alt-RAMEC/PFM protocol as measured by SNA angle (1.16°; 95% CI 0.65 to 1.66), SNB angle (0.67°; 95% CI 0.32 to 1.02) and ANB angle (0.66°; 95% CI 0.08 to 1.25) were noted. Alt-RAMEC/PFM exhibited a more favourable overjet correction when compared to RME/PFM, however, differences in other dental changes were insignificant. Conclusion: There is limited evidence with high risk of bias that Alt-RAMEC/PFM can result in a statistically significant increase in maxillary protraction compared with RME/PFM in Chinese subjects over the short-term. High-quality long-term RCTs with inclusion of patient-reported outcomes are required.

STUDY OBJECTIVES: An oral appliance (OA) is a validated treatment for obstructive sleep apnea (OSA). However, therapeutic response is not certain in any individual and is a clinical barrier to implementing this form of therapy. Therefore, accurate and clinically applicable prediction methods are needed. The goal of this study was to derive prediction models based on multiple awake assessments capturing different aspects of the pharyngeal response to mandibular advancement. We hypothesized that a multimodal model would provide robust prediction. METHODS: Patients with OSA (apnea-hypopnea index [AHI] > 10 events/h) were recruited for treatment with a customized OA (n = 142, 59% male). Participants underwent facial photography (craniofacial structure), spirometry (mid-inspiratory flow at 50% vital capacity [MIF(50)] and mid-expiratory flow at 50% vital capacity [MEF(50)] and the ratio MEF(50)/MIF(50)) and nasopharyngoscopy (velopharyngeal collapse with Mueller maneuver and mandibular advancement). Treatment response was defined by 3 criteria: (1) AHI < 5 events/h plus ≥ 50% reduction, (2) AHI < 10 events/h plus ≥ 50% reduction, (3) ≥ 50% AHI reduction. Multivariable regression models were used to assess predictive utility of phenotypic assessments compared to clinical characteristics alone (age, sex, obesity, baseline AHI). RESULTS: Craniofacial structure and flow-volume loops predicted treatment response. Accuracy of the prediction models (area under the receiver operating characteristic curve) for each criterion were 0.90 (criterion 1), 0.79 (criterion 2), and 0.78 (criterion 3). However, these prediction models including phenotypic assessments did not provide a statistically significant improvement over clinical predictors only. CONCLUSIONS: Multimodal awake phenotyping does not enhance OA treatment outcome prediction. These office-based, awake assessments have limited utility for robust clinical prediction models. Future work should focus on sleep-related assessments. COMMENTARY: A commentary on this article appears in this issue on page 1837. CLINICAL TRIAL REGISTRATION: Registry: Australian New Zealand Clinical Trials Registry, Title: Multimodal phenotyping for the prediction of oral appliance treatment outcome in obstructive sleep apnoea, Identifier: ACTRN12611000409976, URL: https://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?id=336663 CITATION: Sutherland K, Chan AS, Ngiam J, Dalci O, Darendeliler MA, Cistulli PA. Awake multimodal phenotyping for prediction of oral appliance treatment outcome. J Clin Sleep Med. 2018;14(11):1879–1887.

Objectives: To establish the effectiveness of Alternate Rapid Maxillary Expansion and Constriction combined with Protraction Facial Mask (Alt-RAMEC/PFM) approach in treating Class III growing patients compared with PFM combined with conventional Rapid Maxillary Expansion (RME/PFM). Search sources: Unrestricted search in five electronic databases and manual searching were undertaken up to February 2018. Data selection: Randomised clinical trials (RCTs) evaluating the effectiveness of Alt-RAMEC/PFM were selected. Data extraction: Screening of references, data extraction and assessment of bias risk were evaluated independently by two reviewers. Results: Five RCTs comparing the Alt-RAMEC/PFM with RME/PFM met the inclusion criteria. Small but statistically significant mean differences favouring Alt-RAMEC/PFM protocol as measured by SNA angle (1.16°; 95% CI 0.65 to 1.66), SNB angle (0.67°; 95% CI 0.32 to 1.02) and ANB angle (0.66°; 95% CI 0.08 to 1.25) were noted. Alt-RAMEC/PFM exhibited a more favourable overjet correction when compared to RME/PFM, however, differences in other dental changes were insignificant. Conclusion: There is limited evidence with high risk of bias that Alt-RAMEC/PFM can result in a statistically significant increase in maxillary protraction compared with RME/PFM in Chinese subjects over the short-term. High-quality long-term RCTs with inclusion of patient-reported outcomes are required.

Background Management of Class III malocclusion is one of the most challenging treatments in orthodontics, and several methods have been advocated for treatment of this condition. A new treatment protocol involves the use of an alternating rapid maxillary expansion and constriction (Alt-RAMEC) protocol, in conjunction with full-time Class III elastic wear and coupled with the use of temporary anchorage devices (TADs). The aim of this study was to evaluate the dento-skeletal and profile soft tissue effects of this novel protocol in growing participants with retrognathic maxilla. Methods Fourteen growing participants (7 males and 7 females; 12.05 ± 1.09 years), who displayed Class III malocclusions with retrognathic maxilla, were recruited. Pre-treatment records were taken before commencing treatment (T1). All participants had a hybrid mini-implant-supported rapid maxillary expansion (MARME) appliance that was activated by the Alt-RAMEC protocol for 9 weeks. Full-time bone-anchored Class III elastics, delivering 400 g/side, were then used for maxillary protraction. When positive overjet was achieved, protraction was ceased and post-treatment records were taken (T2). Linear and angular cephalometric variables were blindly measured by one investigator and repeated after 1 month. An error measurement (Dahlberg’s formula) study was performed to evaluate the intra-examiner reliability. A paired-sample t test (p

Aim: The purpose of this study was to assess the difference of removal torque values (RTV) and the bone-to-implant contact (BIC) between the sand-blasted, large grit, and acid-etched (SLA) surface-treated and the machined surface (MA) miniscrews. Material and methods: Miniscrews used in this study were 6mm long with a diameter of 1.5mm. A total of 23 SLA miniscrews and 24 MA miniscrews were placed into the distal femoral condyle of 24 New Zealand rabbits. Removal torque test and the BIC was histologically evaluated at 0 and 8 weeks. Results: There was no statistical difference between the RTV in the MA group versus the SLA group at both 0 and 8 weeks. Comparing 0–8 weeks, there was no significant difference in RTV of the SLA group ( P = 0.48), however the change in the MA group was statistically significant ( P = 0.006). Histological observation showed a significant decrease in BIC comparing 0 and 8 weeks for the MA group. The BIC ratio at 8 weeks was statistically significantly higher in the SLA group compared to the MA group. Conclusion: SLA surface preparation does not increase the RTV of miniscrews. Further investigations under loading and a large sample size are required.

Karadeniz, Carmen/0000-0003-2371-9037; Karadeniz, Carmen B/0000-0003-2371-9037; Almuzian, Mohammed/0000-0002-1696-6649; Karadeniz, Ersan/0000-0001-7652-0801; Elekdag-Turk, Selma/0000-0002-2799-6501 WOS: 000412223000013 PubMed: 28339645 Objective:Various factors have been examined in the literature in an attempt to reduce the incidence and severity of root resorption. The purpose of the present investigation is to test the null hypothesis that there is no difference in relation to force level using gradually increasing (ascending) and decreasing (descending) orthodontic force generated by magnets on the severity of Orthodontically Induced Inflammatory Iatrogenic Root Resorption (OIIRR) and amount of tooth movement. Methods:Twenty maxillary first premolars from 10 patients were subjected to ascending (25-225 g, magnets in attraction) and descending (225 to 25 g, magnets in repulsion) buccal forces using a split mouth design over an 8-week period. Polyvinyl siloxane impressions were taken at week 0, 4, and 8 to record the tooth movement. After 8 weeks, the teeth were extracted, scanned, with micro-CT in 16.9 mu m resolution, and the root resorption craters were localized circumferentially and quantified at each level of the root. Results:The total volume of OIIRR with ascending force was 1.20 mm(3), and with descending force was 1.25 mm(3), and there was no statistically significant difference between them. OIIRR on the palatal surface (0.012 mm(3)) was significantly less than on the buccal surface (0.057 mm(3)) and than on the mesial surface (0.035 mm(3)). There is no statistically significant difference in the degree of OIIRR between different level of the root (cervical, middle, and apical) at different surfaces. Moreover, the amount of tooth movement, at 0-, 4-, and 8-week interval, secondary to an ascending and descending force application was not statistically significant. Conclusions:There is no short-term (8 weeks) statistically significant difference between orthodontic ascending and descending forces, from 25 to 225 g and from 225 to 25 g, respectively, in term of severity and location of OIIRR as well as the amount of tooth movement. The buccal surface of the root showed highest degree of OIIRR compared to other root's surfaces. Australian Society of Orthodontists Foundation for Research and Education We acknowledge the Australian Society of Orthodontists Foundation for Research and Education for their financial assistance of this research. The authors also thank Professor William Walsh of the University of New South Wales and Mr Dennis Dwarte of the Australian Centre for Microscopy and Microanalysis for the facilities and the scientific and technical assistance.

Mandibular advancement splints (MAS) are often preferred to CPAP treatment for OSA but are not always equally efficacious. High therapeutic CPAP pressure has been associated with MAS treatment failure in a Japanese population. We sought to assess the relationship between CPAP pressure and MAS treatment response in an Australian population.Therapeutic CPAP pressure and MAS treatment response were obtained from a one-month crossover trial of both treatments. Predictive utility of CPAP pressure to identify MAS treatment response was assessed.Seventy-eight OSA patients were included (age 49.3 ± 11.1 years, BMI 29.1 ± 5.8 kg/m(2)) with predominantly moderate-severe OSA (AHI 30.0 ± 12.7/h). CPAP pressure was lower in MAS responders (MAS AHI10/h) 9.7 ± 1.6 vs. 11.7 ± 2.4 cm H O, p0.01, with area under ROC curve of 0.74 (95% CI 0.63-0.86), p0.01. The best cutoff value of 10.5 cm H O useful for discriminating MAS responders and non-responders in the previous Japanese population, was inadequate for prediction in the current population (0.47 negative predictive value [NPV]). However a cutoff of 13 cm H O identified MAS non-responders (1.0 NPV). Multivariate regression identified CPAP pressure (odds ratio [95% confidence interval] 0.53 [0.33-0.87], age (0.93 [0.87-0.99]) and AHI (0.92 [0.86-0.97]) as predictors of MAS treatment response (model r(2) = 0.54, p0.001).In Australian patients, the majority of whom are Caucasian, a higher therapeutic CPAP pressure requirement in conjunction with age and OSA severity characteristics may be useful to indicate likelihood of success with MAS as an alternative therapy.

Orthodontic root resorption is a common side effect of orthodontic therapy. It has been shown that high hydrostatic pressure in the periodontal ligament (PDL) generated by orthodontic forces will trigger recruitment of odontoclasts, leaving resorption craters on root surfaces. The patterns of resorption craters are the traces of odontoclast activity. This study aimed to investigate resorptive patterns by: (i) quantifying spatial root resorption under two different levels of in vivo orthodontic loadings using microCT imaging techniques and (ii) correlating the spatial distribution pattern of resorption craters with the induced mechanobiological stimulus field in PDL through nonlinear finite-element analysis (FEA) in silico . Results indicated that the heavy force led to a larger total resorption volume than the light force, mainly by presenting greater individual crater volumes ( p < 0.001) than increasing crater numbers, suggesting that increased mechano-stimulus predominantly boosted cellular resorption activity rather than recruiting more odontoclasts. Furthermore, buccal–cervical and lingual–apical regions in both groups were found to have significantly larger resorption volumes than other regions ( p < 0.005). These clinical observations are complemented by the FEA results, suggesting that root resorption was more likely to occur when the volume average compressive hydrostatic pressure exceeded the capillary blood pressure (4.7 kPa).

Introduction: The effect of zoledronic acid, a potent and novel bisphosphonate, on tooth movement and orthodontically induced root resorption in osteoporotic animals systemically treated with zoledronic acid as similarly used in postmenopausal patients has not been elucidated. Therefore, this study was undertaken. Methods: Fifteen 10-week-old female Wistar rats were divided into 3 groups: ovariectomy, ovariectomy + zoledronic acid, and control. Only the ovariectomy and ovariectomy + zoledronic acid groups underwent ovariectomies. Two weeks after the ovariectomy, zoledronic acid was administered only to the ovariectomy + zoledronic acid group. Four weeks after the ovariectomy, 25-g nickel-titanium closed-coil springs were applied to observe tooth movement and orthodontically induced root resorption. Results: There were significant differences in the amounts of tooth movement and orthodontically induced root resorption between the ovariectomy and the control groups, and also between the ovariectomy and the ovariectomy + zoledronic acid groups. There was no statistically significant difference in tooth movement and orthodontically induced root resorption between the ovariectomy + zoledronic acid and the control groups. Zoledronic acid inhibited significantly more tooth movement and significantly reduced the severity of orthodontically induced root resorption in the ovariectomized rats. The ovariectomy + zoledronic acid group showed almost the same results as did the control group in both tooth movement and orthodontically induced root resorption. Conclusions: Zoledronic acid inhibits excessive orthodontic tooth movement and also reduces the risk of severe orthodontically induced root resorption in ovariectomized rats., American Journal of Orthodontics and Dentofacial Orthopedics, 141(5), pp.563-573; 2012

colak, canan/0000-0002-5289-1787; Elekdag-Turk, Selma/0000-0002-2799-6501; Darendeliler, Mehmet Ali/0000-0002-8906-8153 WOS: 000297994200006 PubMed: 22133964 Introduction: Microcomputed tomography offers a unique opportunity to accurately examine orthodontically induced inflammatory root resorption. The aims of this study were to quantify, in 3 dimensions, the amount of root resorption caused by placing heavy and light distal root tipping forces on premolars and to compare the prevalence of root resorption in different areas of the tooth. Methods: Thirty maxillary first premolars from 15 patients who were to have these teeth extracted as part of their orthodontic treatment were selected for this study. Each tooth in the same patient was randomly chosen to have either a 2.5 degrees or a 15 degrees distal root tipping bend placed for 4 weeks. After the experimental period, the teeth were extracted according to a strict protocol to prevent damage to the root. They were then imaged by a microcomputed tomography scan x-ray system (SkyScan 1172, SkyScan, Aartselaar, Belgium) and analyzed by software designed for volumetric measurements. Results: A significant difference was found in the amount of total root resorption between light and heavy forces (P = .021). The mean cube root volumes of the resorption craters in the 15 degrees tip-bend group were greater than in the 2.5 degrees tip-bend group. This significance was lost when the tooth was divided into vertical thirds, although a trend was still present. When the areas of expected compression in the periodontal ligament were compared with the areas of expected tension, significance was seen in the apical and cervical thirds only. Conclusions: Based on this experiment, one can conclude that a 15 degrees distal root tip bend causes more orthodontically induced inflammatory root resorption than a 2.5 degrees distal root tip bend. Furthermore, greater root resorption was found in areas under pressure when compared with areas under tension. (Am J Orthod Dentofacial Orthop 2011;140:e299-e305)

Objective: To quantify the amount of tooth movement and orthodontically induced root resorption (OIRR) in ovariectomized rats. \nMaterials and Methods: Five 10-week-old female Wistar rats undergoing ovariectomy (OVX) were investigated as the experimental group, and the other five without ovariectomy served as the control group. Four weeks after ovariectomy, 25-g nickel-titanium closed-coil springs were applied mesially to the maxillary left first molars. Micro–computed tomography was taken at day 0, 1, 3, 7, 14, 21, and 28. At day 28, the molars were extracted. The surface area of root resorption craters, depth, and volume were measured using electron and laser scanning microscopes. \nResults: Tooth movement gradually increased with time throughout 28 days. There was a significant difference in the amount of tooth movement between the control group and the OVX group. For OIRR, the OVX group showed wide and shallow root resorption craters scattered on the mesial root. The deep resorption craters were observed on the distal roots distributed in the cervical, middle, and apical thirds of the roots. Statistically significant differences were found between the control and the OVX groups in the depth and the volume of root resorption craters in the distal roots and the total volume of root resorption craters in all three roots. \nConclusion: Ovariectomy affected not only tooth movement but also OIRR. Tooth movement in the OVX group was more rapid than the control group. Furthermore, the amount of OIRR in the OVX group was more severe than the control group., The Angle Orthodontist, 81(4), pp.570-577; 2011

Mandibular advancement splints (MASs) can effectively treat obstructive sleep apnea (OSA); however, no validated and reliable prediction method for treatment outcome currently exists. The efficacy of MAS may relate to anatomic factors, including craniofacial size and upper-airway soft-tissue volume and anatomic balance between them. We aimed to assess whether craniofacial and oral measurements are associated with MAS treatment outcome.Dental impressions and lateral cephalometric radiographs were obtained from patients with OSA prior to commencing MAS treatment. Intertooth distances and palatal depths were measured on dental casts, and standard cephalometric analysis was performed with the addition of cross-sectional area (CSA) of the tongue and bony oral enclosure. Treatment outcome was determined by polysomnography.Of 53 patients, 25 were complete responders (posttreatment apnea-hypopnea index [AHI]5/h), 17 were partial responders (≥ 50% AHI reduction), and 11 were nonresponders (50% AHI reduction). Cephalometric analyses did not reveal any significant differences between responders and nonresponders. Oral cavity measurements or CSA did not differ with treatment outcome; however, there was a trend toward a larger tongue CSA in complete vs partial and nonresponders (39.5 ± 1.3 cm(2) vs 35.5 ± 0.5 cm(2), P = .09). Tongue/oral enclosure CSA ratio, indicating a larger tongue for a given oral cavity size, was greater in complete responders (P = .012, n = 30).Oral dimensions do not appear to differ between patients who respond and those who do not respond to MAS treatment. However, the larger tongue for a given oral cavity size in responders suggests that MAS may help to correct anatomic imbalance. Further research to assess whether the ratio between tongue and bony oral enclosure size may be useful in selecting patients for MAS treatment is warranted.

colak, canan/0000-0002-5289-1787; Darendeliler, Mehmet Ali/0000-0002-8906-8153; Elekdag-Turk, Selma/0000-0002-2799-6501 WOS: 000288982500010 PubMed: 21457842 Introduction: Root resorption is an undesirable consequence of orthodontic tooth movement. The severity is unpredictable, and, despite extensive research, the etiology remains unknown. Torque has been acknowledged as a risk factor for root resorption. The aims of the study were to evaluate and quantify the extent of root resorption after the application of 2.5 degrees and 15 degrees of buccal root torque for 4 weeks. Methods: Fifteen patients requiring bilateral extraction of their maxillary first premolars for orthodontic treatment were recruited to the study. By using a standardized experimental protocol, the right and left premolars were randomly subjected to either 2.5 degrees or 15 degrees of buccal root torque. At the end of the 4-week experimental period, the premolars were extracted. A volumetric analysis of root resorption was performed by using microcomputed tomography and measured with specially designed software. Results: Overall, the amounts of root resorption were comparable after the application of 2.5 degrees or 15 degrees of buccal root torque (P = 0.59). There was a significant difference between the 2 force levels only at the apical region (P = 0.034). More root resorption occurred in areas of compression than in areas of tension. The variables of age and sex were not statistically significant. Conclusions: Root resorption was evident after 4 weeks of buccal root torque application. More root resorption was seen at the apical region than at the middle and cervical regions. Higher magnitudes of torque might cause more root resorption, particularly in the apical region. As shown in previous studies, the etiology of root resorption is multi-factorial and cannot be explained by mechanical factors alone. (Am J Orthod Dentofacial Orthop 2011;139:e353-e360) Australian Society of Orthodontics Foundation for Research and Education; Australian Dental Research Foundation Supported by the Australian Society of Orthodontics Foundation for Research and Education and the Australian Dental Research Foundation.

STUDY OBJECTIVES Oral appliances are increasingly being used for treatment of obstructive sleep apnea (OSA). Mandibular advancement splint (MAS) mechanically protrudes the mandible, while the tongue stabilizing device (TSD) protrudes and holds the tongue using suction. Although both appliances can significantly improve or ameliorate OSA, their comparative effects on upper airway structure have not been investigated. DESIGN Cohort study. SETTING Sleep Investigation Unit. PATIENTS 39 patients undergoing oral appliance treatment for OSA. INTERVENTIONS OSA patients underwent magnetic resonance imaging (MRI) of the upper airway during wakefulness at baseline and with MAS and TSD in randomized order. Treatment efficacy was determined by polysomnography in a subset of 18 patients. MEASUREMENTS AND RESULTS Upper airway lumen and surrounding soft tissue structures were segmented using image analysis software. Upper airway dimensions and soft tissue centroid movements were determined. Both appliances altered upper airway geometry, associated with movement of the parapharyngeal fat pads away from the airway. TSD increased velopharyngeal lateral diameter to a greater extent (+0.35 ± 0.07 vs. +0.18 ± 0.05 cm; P

Objectives: To histologically and immunohistochemically assess the pattern of expression of bone morphogenic proteins 2 and 4 (BMP2/4) and proliferating cell nuclear antigen (PCNA) in response to bite jumping appliances in the condylar cartilage and the glenoid fossa. Materials and Methods: Fifty-five 4-week-old female Sprague-Dawley rats were randomly divided into four experimental and four control groups. Bite-jumping appliances were fitted to the experimental animals. The rats were sacrificed at 3, 14, 21, and 30 days, and the temporomandibular structures were analyzed histologically and immunohistochemically. Results: The expression of BMP2/4 in response to bite-jumping appliances was statistically significant in the condylar cartilage and the glenoid fossa. Cell proliferation was not significant. Conclusion: BMP2/4 plays an important role in bone formation in response to mandibular advancement by accelerating and enhancing the differentiation of mesenchymal cells into boneforming cells. (Angle Orthod. 2011;81:91–99.)

Our objectives were to correlate the mineral density (MD) and elastic modulus (E) of natural white spot lesions (WSLs) and compare them with analytical and numerical models. Five natural WSLs from four extracted sound premolar teeth were scanned at a voxel size of 7.6μm using a desktop X-ray microtomography (XRMT) system. Five hydroxyapatite phantoms with densities ranging from 1.52 to 3.14gcm⁻³ were used as calibration standards for each scan. MD throughout the WSLs was quantified using an MD calibration equation derived from hydroxyapatite phantoms. Subsequently, teeth were cross-sectioned and the E modulus was measured systematically across the WSLs at intervals of 25 and 50μm using nanoindentation. The MD and E modulus of WSLs correlated well. The relationship may be expressed as E=E⁰exp(-bP) (R²=0.952) with E⁰ the elastic modulus of the fully dense material, P the porosity and b a constant. The results for sound enamel were compared with Spears model. The limitation of Spears model to the WSLs is discussed and an alternative model developed by Rice for porous materials is proposed. Clinical implications of this work for quantifying de-/remineralization of teeth are pointed out. We conclude that XRMT can be utilized to extrapolate the E modulus of WSLs. This provides a basis for non-destructive, longitudinal analysis of WSLs in de-/remineralization studies of enamel.

Objective: To test the hypothesis that the administration of aspirin, acetaminophen, meloxicam, celecoxib, and prednisolone have no effect on root resorption and tooth movement. Materials and Methods: A mesial force of 50 g was applied to the left maxillary first molars of sixty 10-week-old male Wistar rats using nickel titanium closed coil springs attached to the cervical area of the incisors. The rats were randomly divided into 12 groups of 5 each. High and low doses of aspirin, acetaminophen, meloxicam, celecoxib, and prednisolone were administered via drinking water for 2 weeks. The experimental control group had tooth movement but received no drug. The negative control group received neither tooth movement nor drugs. The amount of tooth movement was measured on digitized lateral cephalometric radiographs. Rats were sacrificed after 2 weeks. Mesial and distal roots (distobuccal and distopalatal) were examined using scanning electron and three-dimensional (3D) scanning laser microscopes. The surface area, depth, volume, and roughness of the root resorption craters were measured. Results: When compared with experimental control rats, only prednisolone- and high-dose celecoxib-treated groups showed significantly less root resorption and less tooth movement. Although low dose celecoxib-treated group significantly decreased the tooth movement, root resorption was similar to the control group. Furthermore, resorption craters showed a smoother surface in the prednisolone-treated rats. Conclusions: The hypothesis was rejected. Administration of prednisolone and high-dose celecoxib reduces root resorption and interferes with tooth movement in rats. Both drugs may interfere in the arachidonic acid cascade depending on dose thresholds., The Angle Orthodontist, 79(4), pp.715-726; 2009

OBSTRUCTIVE SLEEP APNEA (OSA) IS A COMPLEX MULTIFACTORIAL CONDITION PRODUCED BY A COMBINATION OF ANATOMIC AND PHYSIOLOGICAL FACTORS.1 It is characterized by repetitive complete or partial closure of the upper airway during sleep resulting in sleep fragmentation and oxygen desaturation.2,3 Numerous risk factors including male gender and obesity,4 ethnicity,5 and craniofacial structure6 have been identified as increasing susceptibility to this disease. OSA has a significant associated morbidity and mortality and has been linked to cardiovascular7,8 and cerebrovascular disease,9,10 excessive daytime sleepiness,11 and increased risk for motor vehicle accidents.12–14 The prevalence of OSA varies depending on diagnostic criteria and population studied, and has been reported as affecting 4% of men and 2% of women in the middle-aged workforce.15 It was also found that among adults aged 30-69 years, 17% of adults had mild or worse sleep disordered breathing (AHI ≥ 5), and 5.7% of adults had moderate or worse sleep disordered breathing.16 As such, OSA is recognized as a significant public health issue. While the gold standard of care combines conservative modalities such as weight loss and nasal continuous positive airway pressure (CPAP),17 interest in oral devices has been increasing possibly because of compliance difficulties with CPAP. Mandibular advancement splints (MAS) are the most common type of oral device; they protrude the mandible during sleep, thereby having a favorable impact on upper airway structure and function. Several designs have been extensively investigated and shown to be efficacious in a substantial number of patients, particularly those with mild to moderate OSA.18–21 The American Academy of Sleep Medicine practice parameters recommend the use of MAS as an alternative to CPAP for patients who prefer oral appliances or refuse or are unable to tolerate CPAP, particularly in mild to moderate OSA.22 A tongue stabilizing device (TSD) is a preformed appliance and uses suction to protrude the tongue and improve upper airway structure and function. The earlier designs were similar to a mouthguard, covering the upper and lower teeth to assist retention, with a flexible bulb into which the tongue was protruded.23 The current design has no dental coverage, reduced bulk, and has the bulb being retained in place only by suction. There are currently only limited data on the efficacy of the current device, which is commercially available.24 As they are not reliant on the teeth for retention, TSD have been proposed as an option for patients with a reduced number or absence of teeth (hypodontia, edentulism), or compromised dental health (periodontal disease). The aim of this study was to compare the efficacy of these 2 types of oral devices in typical OSA patients.

The differentiation and functions of osteoclasts are regulated by the receptor activator of nuclear factor kappa beta (RANK) and its ligand (RANKL). The present study was designed to identify the expression of RANK/RANKL in the event of root resorption provoked by excessive orthodontic force and also to explore the biological mechanism of the RANK/RANKL system in regulating odontoclastogenesis in root cementum. Thirty male Wistar rats were subjected to orthodontic force of 100 g to induce a mesially tipping movement of the left mandibular first molars. The contralateral molars served as intraindividual controls. The rats were sacrificed after 3, 7, or 10 days. The mandibular body surrounding the molars was harvested and serial sections of 6-μm thickness were cut. Immunohistochemical assays were conducted to localize the expression of RANK/RANKL proteins and histomorphological examination was undertaken to identify cellular response in cementum, periodontal ligament, and alveolar bone during root resorption. Root resorption in cementum occurred at the sites corresponding to compression of the periodontal ligament, indicated by increased numbers of multinucleated osteoclasts and odontoclasts. Immunoreaction against RANKL became stronger in osteoblasts, osteoclasts, odontoclasts, and fibroblasts of the periodontal ligament from Day 3 onwards. The number of positively immunoreactive cells against RANK also increased significantly over Days 3, 7, and 10 (p