Differences in dentofacial morphology in children with sleep disordered breathing are detected with routine orthodontic records.

BACKGROUND: Residual snoring in children with obstructive sleep disordered breathing (SDB) may continue post-adenotonsillectomy. This study aims to identify baseline dentofacial differences in children with SDB using routine orthodontic records that might aid effective early intervention for the upper airway to prevent continued obstruction. METHODS: Children (6-16 years) with clinically diagnosed SDB from a paediatric Otolaryngology Clinic who required adenotonsillectomy were participants (n = 10). The control group (n = 9) comprised healthy non-snoring children from the community. Baseline overnight polysomnography (PSG), standardised frontal and right profile photographs and alginate impressions were taken of all children. Facial width, length, depth, convexity and mandibular position were measured from the photographs. The occlusion, arch width, arch depth, maxillary arch form, palatal height and volume were recorded from digitised dental models. Inter-group differences were compared. RESULTS: SDB patients had a significantly increased lower face height, maxillo-mandibular angle (1.73°; 95% CI 0.45-3.0) and a narrower maxillary arch in the upper posterior region. There was a trend towards a decreased palatal volume, increased posterior crossbite and Class II molar relationship. CONCLUSION: Dentofacial phenotypic differences between children with SDB and controls can be detected using facial photographs and dental models. Increased awareness of these features may help to identify children who to continue to snore post adenotonsillectomy.

The influence of miniscrew insertion torque.

Objective: The aim of this in vitro study was to evaluate the progressive development of surface microdamage produced following the insertion of orthodontic miniscrews (OMs) into 1.5 mm thick porcine tibia bone using maximum insertion torque values of 12 Ncm, 18 Ncm, and 24 Ncm. Methods: Aarhus OMs (diameter 1.5 mm; length 6 mm) were inserted into 1.5 mm porcine bone using a torque limiting hand screwdriver set at 12 Ncm, 18 Ncm, and 24 Ncm. A custom rig equipped with a compression load cell was used to record the compression force exerted during manual insertion. A sequential staining technique was used to identify microdamage viewed under laser confocal microscopy. Virtual slices were created and stitched together to form a compressed two-dimensional composition of the microdamage. Histomorphometric parameters, including total damage area, diffuse damage area, maximum crack length, maximum damage radius, and maximum diffuse damage radius, were measured. Kruskal-Wallis Tests and Wilcoxon Rank-Sum Tests were used to analyse the generated data. Results: All OMs inserted using 12 Ncm failed to insert completely, while partial insertion was observed for two OMs inserted at 18 Ncm. Complete insertion was achieved for all OMs inserted at 24 Ncm. Histomorphometrically, OMs inserted using 24 Ncm produced a significantly larger diffuse damage area (P < 0.05; P < 0.05) and maximum diffuse damage radius (P < 0.05; P < 0.05), for both the entry and exit surfaces, respectively, compared with the 12 Ncm and 18 Ncm groups. Conclusions: Insertion torque can influence the degree of OM insertion and, subsequently, the amount of microdamage formed following insertion into 1.5 mm thick porcine tibia bone. An increase in insertion torque corresponds with greater insertion depth and larger amounts of microdamage.

Influence of cortical bone thickness on miniscrew microcrack formation.

INTRODUCTION: The aim of this in-vitro study was to investigate the influence of cortical bone thickness on the amount of surface microdamage produced after insertion of orthodontic miniscrews (OM) in porcine tibia bone. METHODS: Aarhus OMs (Medicon, Tuttlingen, Germany; diameter, 1.5 mm; length, 6 mm) were inserted into 1.0 mm (group A; n = 10), 1.5 mm (group B; n = 10), and 2.0 mm (group C; n = 10) of porcine cortical bone using a torque-limiting hand screwdriver set at 18 Ncm. A sequential staining technique was used to identify microdamage under laser confocal microscopy. Virtual slices were stitched together using ImageJ software (National Institutes of Health, Bethesda, Md) to form a compressed 2-dimensional composition of the microdamage. The ImageJ software was used to quantify the total damage area, diffuse damage area, maximum crack length, maximum damage radius, and maximum diffuse damage radius. Kruskal-Wallis tests and Wilcoxon rank sum tests were used to analyze the data. RESULTS: All OMs in group A (1.0 mm) were inserted completely; however, 2 OMs from group B (1.5 mm) and all OMs in group C (2.0 mm) failed to insert completely. The entry surface of group C (2.0 mm) exhibited significantly higher amounts of total damage, diffuse damage area, maximum crack length, and maximum crack damage radius compared with groups A (1.0 mm) and B (1.5 mm). The maximum crack length observed on the entry and exit surfaces ranged from 1.03 to 3.06 mm. CONCLUSIONS: In this study, we demonstrated a higher level of microdamage after the insertion of OMs into 2.0-mm thick cortical bone compared with 1.0-mm thick cortical bone. Therefore, clinicians need to consider the thickness of the cortical bone at the insertion site, because mechanisms to reduce cortical bone thickness would likely reduce the amount of microdamage formed. A safety zone of 3.5 mm from the OM is also recommended for OMs inserted into 1.0- and 1.5-mm cortical bone thicknesses to minimize any detrimental effects after targeted remodeling.

Qualitative evaluation of pretreatment patient concerns in orthodontics.

INTRODUCTION: A discrepancy exists between objective and subjective measures of orthodontic treatment need, highlighting the importance of patients' perceptions. Limited qualitative information is available regarding patients' perceptions and orthodontic concerns. For the first time, patient facial images and qualitative methodology were used to assess patients' orthodontic concerns, which are incorporated into and are important in treatment planning and consent. METHODS: An interview-based, cross-sectional study of adolescent patients eligible to receive orthodontic treatment in a public dental hospital was conducted with 105 adolescents (42 boys, 63 girls) aged between 12 and 17 years. Each patient's face was video recorded, and 3 images were selected from each recording to assess the patient's orthodontic concerns. The initial chief concerns were compared with concerns articulated after the patients assessed their facial images. In addition, patient concerns were compared with occlusal features visible on smiling using the Dental Aesthetic Index and patient study casts. RESULTS: For 37% of the adolescent patients, smiling images helped to identify additional concerns. For 87%, their smiling images helped them to describe their concerns in more detail. In addition, a few patients did not articulate any concern about features measurable on the Dental Aesthetic Index that were visible on smiling. CONCLUSIONS: Showing adolescent patients images of their face and smile helped them to identify and better describe their concerns. Adolescents are not always overly concerned about visible and quantifiable malocclusion features. This might influence orthodontic treatment planning and consent.

The efficacy of Hybrid Hyrax-Mentoplate combination in early Class III treatment: a novel approach and pilot study.

INTRODUCTION: The aim of the present study was to assess the skeletal, dental and soft tissue effects of a specific treatment protocol in consecutively treated patients who presented with a Class III malocclusion. Treatment involved the use of a Hybrid Hyrax (HH) in the maxilla, a Mentoplate in the mandible and the application of continuous intra-oral Class III elastics. METHOD: The treated group was comprised of seven males and seven females (mean pretreatment age 10.4 ± 1.7 yr, range 7.8-12.9 yr). Treatment changes were analysed on lateral cephalograms taken 6-12 months prior to commencing treatment (T1) and at the finish of the orthopaedic phase (T2). Where a normality assumption was met, a parametric paired-sample t-test was used to assess the change differences at T1 and T2. For non-normal data, a non-parametric Wilcoxon sign rank test for related samples was used to assess T1 and T2 differences. The level of statistical significance was set at p < 0.05 (2-tailed). RESULTS: The average sagittal changes showed an improved SNA angle of 2.1 ± 2° (p = 0.002), an ANB angle of 1.9 ± 1.8° (p = 0.002), a Wits improvement of 3.4 ± 2.7 mm (p < 0.001) and an overjet reduction of 2.0 ± 2.2 mm (p = 0.005). There were no statistically significant correlations found between the age at T1, age at treatment start and age at T2 and the changes identified in the cephalometric variables (T2-T1). CONCLUSION: The HH-Mentoplate Class III treatment protocol induced a mean Wits improvement of 3.4 mm in the maxillary and mandibular sagittal base relationship at the functional occlusal level. This was primarily achieved by sagittal maxillary skeletal protraction with negligible effects on the mandible, facial vertical dimension and the incisor angulations. A controlled clinical study with larger sample sizes and longer follow-up times is needed.

The psycho-social impact of malocclusions and treatment expectations of adolescent orthodontic patients.

OBJECTIVES: To evaluate the short- and long-term orthodontic treatment (OT) expectations, malocclusion severity, and oral health-related quality of life (OHRQoL) status of adolescent patients using qualitative and quantitative methodology. MATERIALS AND METHODS: Adolescents (n = 105; 42 males and 63 females) aged between 12 and 17 years participated in this interview and questionnaire-based study. The Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) and the Oral Impacts on Daily Performances (OIDP) scale evaluated OHRQoL status. Study casts were analysed using the Dental Aesthetics Index (DAI) and the Index of Complexity, Outcome and Need (ICON). Mann-Whitney test and Spearman's correlations tested various univariate variables. RESULTS: With similar index-determined OT need (DAI, P = 0.371 and ICON, P = 0.932) females tended to have worse OHRQoL status (PIDAQ scores, P-values ranged from 0.006 to 0.0001 and scores for the OIDP question related to smiling, laughing, and showing teeth without embarrassment, P-value = 0.015). Occlusal index scores did not have statistically significant associations with the OHRQoL scales. Better dental appearance was expected by 85 per cent of the adolescents in the short-term and by 51 per cent in the long-term after OT. The associated psycho-social expectations were: 1. improved dental self-confidence, 2. positive psychological impact/improved self-worth, and 3. positive social impact. CONCLUSIONS: Female adolescent patients tended to experience worse psycho-social impacts related to their malocclusions compared with males with similar index-determined OT need. Index-determined OT need scores did not correlate with the OHRQoL scales. Adolescent patients expected OT to improve their dental appearance and QoL aspects.

A qualitative investigation of RANKL, RANK and OPG in a rat model of transient ankylosis.

INTRODUCTION: Previous studies have found ankylosis occurs as a part of the inflammatory process of aseptic root resorption initiated in a rat model. The physiologic mechanisms behind the development of dentoalveolar ankylosis and healing response are still unclear. While receptor activator of nuclear factor-κß ligand (RANKL), receptor activator of nuclear factor-κß (RANK) and osteoprotegerin (OPG) have gained momentum in the understanding of resorption, no study to date has investigated their role in dentoalveolar ankylosis. AIMS: The aims of this study were to investigate if, and when, ankylosis occurred in the rat PDL, whether the resolution of ankylosis occurred with time and, finally, to observe the expression of RANKL, RANK and OPG during the ankylotic process. MATERIALS AND METHODS: Dry ice was applied for 20 minutes to the upper right first molar crown of 15 eight-week-old, male Sprague-Dawley rats. An additional three rats served as untreated external controls. Groups of three rats were sacrificed after the thermal insult on day 0, 4, 7, 14 and 28 respectively. Each maxilla was dissected out and processed for histological examination and RANKL, OPG and RANK immunohistochemistry. RESULTS: By the use of light microscopy and H&E staining, no ankylosis was detected in the external control group and the experimental groups at days 0 and 4. On day 7, disruption within the periodontal ligament was observed in the interradicular region and the initial signs of ankylosis were seen in the form of finger-like projections extending from the alveolar bone towards the cementum. Fourteen days after the thermal insult, all animals exhibited extensive ankylosis that spanned the entire interradicular periodontal space. At 28 days, the development of ankylosis appeared to have ceased and repair was observed, together with an intact periodontal ligament in all but one rat. Positive staining results were obtained with RANKL, RANK and OPG antibodies. The expressions of RANKL, RANK and OPG were similar in the external control group, 0-, 4-, and 28-day experimental groups. In the 7- and 14-day experimental groups, RANKL, RANK and OPG were expressed in the blood vessels within the ankylotic regions. CONCLUSIONS: During the development of ankylosis and its resolution, it was concluded from their simultaneous presence that there is a complex interaction between RANKL, RANK and OPG that requires further investigation.

Accelerating orthodontic tooth movement with the aid of periodontal surgery--the practitioner viewpoint.

INTRODUCTION: There has been a revival of interest in the acceleration of orthodontic tooth movement (OTM) by inducing injury to dentoalveolar cortical bone. Termed corticotomy, the procedure offers an advantage to adult patients whose bone metabolism is such that any reduction in treatment time would be welcomed. The procedure has been refined for over 100 years and recent research indicates treatment duration may be reduced often by as much as a third, but it is not clear how widely the method is applied in practice. For the procedure to be successful, careful interdisciplinary management by orthodontists and periodontists is required. However, information regarding the attitude and knowledge of practitioners and the frequency of the procedure performed in Australia and New Zealand is lacking. METHODS: A questionnaire was formulated and tested in a pilot study on postgraduate orthodontic and periodontic students at The University of Adelaide. As a consequence of the responses, the wording of several questions was clarified and the sequence modified to produce the final format. Separate questionnaires were developed for specialist orthodontists and periodontists in keeping with their different backgrounds and were distributed at two relevant conferences. RESULTS AND CONCLUSIONS: The number of practitioners who had been involved with at least one corticotomy per annum was low for orthodontists (12%) and periodontists (18%). The majority of those surveyed believed that more research was required on corticotomy-facilitated OTM and would not recommend the procedure to patients without greater investigation of the technique. More than half of the sampled orthodontists indicated that they would never recommend corticotomy-facilitated orthodontics to their patients. The minority who were willing to recommend the procedure would limit involvement to adult patients, the management of ankylosed teeth, impacted canines and patients susceptible to root resorption. Over 90% of the sampled periodontists believed that there were adverse side effects.

Craniofacial and upper airway morphology in pediatric sleep-disordered breathing and changes in quality of life with rapid maxillary expansion.

INTRODUCTION: The association between pediatric sleep-disordered breathing caused by upper airway obstruction and craniofacial morphology is poorly understood and contradictory. The aims of this study were to evaluate the prevalence of children at risk for sleep-disordered breathing, as identified in an orthodontic setting by validated screening questionnaires, and to examine associations with their craniofacial and upper airway morphologies. A further aim was to assess the change in quality of life related to sleep-disordered breathing for affected children undergoing rapid maxillary expansion to correct a palatal crossbite or widen a narrow maxilla. METHODS: A prospective case-control study with children between 8 and 17 years of age (n = 81) at an orthodontic clinic was undertaken. The subjects were grouped as high risk or low risk for sleep-disordered breathing based on the scores from a validated 22-item Pediatric Sleep Questionnaire and the Obstructive Sleep Apnea-18 Quality of Life Questionnaire. Variables pertaining to a screening clinical examination, cephalometric assessment, and dental cast analysis were tested for differences between the 2 groups at baseline. Ten children who underwent rapid maxillary expansion were followed longitudinally until removal of the appliance approximately 9 months later with a repeated Obstructive Sleep Apnea-18 Quality of Life Questionnaire. All data were collected blinded to the questionnaire results. RESULTS: The frequency of palatal crossbite involving at least 3 teeth was significantly higher in the high-risk group at 68.2%, compared with the low-risk group at 23.2% (P <0.0001). Average quality of life scores in the high-risk group indicated reduced quality of life related to sleep-disordered breathing by 16% compared with children in the low-risk group at baseline (P <0.0001). Cephalometrically, mean inferior airway space, posterior nasal spine to adenoidal mass distance, and adenoidal mass to soft palate distance were reduced in the high-risk group compared with the low-risk group by 1.87 mm (P <0.03), 2.82 mm (P <0.04), and 2.13 mm (P <0.03), respectively. The mean maxillary intercanine, maxillary interfirst premolar, maxillary interfirst molar, mandibular intercanine, and mandibular interfirst premolar widths were reduced in the high-risk group compared with the low-risk group by 4.22 mm (P <0.0001), 3.92 mm (P <0.0001), 4.24 mm (P <0.0001), 1.50 mm (P <0.01), and 1.84 mm (P <0.01), respectively. Children treated with rapid maxillary expansion showed an average improvement of 14% in quality of life scores in the high-risk group compared with the low-risk group, which showed a slight worsening in quality of life related to sleep-disordered breathing by an average of 1% (P <0.04), normalizing the quality of life scores in the high-risk children to the baseline scores compared with the low-risk group. CONCLUSIONS: Children at high risk for sleep-disordered breathing are characterized by reduced quality of life, reduced nasopharyngeal and oropharyngeal sagittal dimensions, palatal crossbite, and reduced dentoalveolar transverse widths in the maxillary and mandibular arches. No sagittal or vertical craniofacial skeletal cephalometric predictors were identified for children at high risk for sleep-disordered breathing. In the short term, rapid maxillary expansion might aid in improvement of the quality of life for children with a narrow maxilla in the milder end of the sleep-disordered breathing spectrum.

Craniofacial and upper airway morphology in pediatric sleep-disordered breathing: Systematic review and meta-analysis.

INTRODUCTION: Pediatric sleep-disordered breathing is a continuum, with primary snoring at one end, and complete upper airway obstruction, hypoxemia, and obstructive hypoventilation at the other. The latter gives rise to obstructive sleep apnea. An important predisposing factor in the development and progression of pediatric sleep-disordered breathing might be craniofacial disharmony. The purpose of this systematic review and meta-analysis was to elucidate the association between craniofacial disharmony and pediatric sleep-disordered breathing. METHODS: Citations to potentially relevant published trials were located by searching PubMed, Embase, Scopus, and the Cochrane Central Register of Controlled Trials. The MetaRegister of controlled trials database was also searched to identify potentially relevant unpublished trials. Additionally, hand-searching, Google Scholar searches, and contact with experts in the area were undertaken to identify potentially relevant published and unpublished studies. Inclusion criteria were (1) randomized controlled trials, case-control trials, or cohort studies with controls; (2) studies in nonsyndromic children 0 to 18 years of age with a diagnosis of sleep-disordered breathing or obstructive sleep apnea by either a sleep disorders unit, screening questionnaire, or polysomnography; and (3) principal outcome measures of craniofacial or upper airway dimensions or proportions with various modalities of imaging for the craniofacial and neck regions. The quality of the studies selected was evaluated by assessing their methodologies. Treatment effects were combined by meta-analysis with the random-effects method. RESULTS: Children with obstructive sleep apnea and primary snoring show increased weighted mean differences in the ANB angle of 1.64° (P <0.0001) and 1.54° (P <0.00001), respectively, compared with the controls. An increased ANB angle was primarily due to a decreased SNB angle in children with primary snoring by 1.4° (P = 0.02). Children with obstructive sleep apnea had a distance from the posterior nasal spine to the nearest adenoid tissue measured along the PNS-basion line reduced by 4.17 mm (weighted mean difference) (P <0.00001) and a distance from the posterior nasal spine to the nearest adenoid tissue measured along the line perpendicular to the sella-basion line reduced by 3.12 mm (weighted mean difference) (P <0.0001) compared with the controls. CONCLUSIONS: There is statistical support for an association between craniofacial disharmony and pediatric sleep-disordered breathing. However, an increased ANB angle of less than 2° in children with obstructive sleep apnea and primary snoring, compared with the controls, could be regarded as having marginal clinical significance. Therefore, evidence for a direct causal relationship between craniofacial structure and pediatric sleep-disordered breathing is unsupported by this meta-analysis. There is strong support for reduced upper airway width in children with obstructive sleep apnea. Larger well-controlled trials are required to address the relationship of craniofacial and upper airway morphology to pediatric sleep-disordered breathing in all 3 dimensions.

Facial aesthetics and perceived need for further treatment among adults with repaired cleft as assessed by cleft team professionals and laypersons.

The objectives of this study were to compare the ratings of professionals and laypeople with and without a cleft regarding the facial aesthetics of adult patients previously treated for orofacial clefting. The necessity for further treatment, as perceived by the respective groups, is also compared. The design of the study was a cross-sectional study. Professionals (two plastic surgeons, one dentist, one orthodontist, and one psychologist) and laypeople (one male and one female adult without a cleft and one male and one female adult with a cleft) were recruited to rate photographs of 80 non-syndromic cleft patients treated by the Australian Craniofacial Unit from 1975 to 2009. Facial aesthetics were measured by a visual analogue scale (VAS; 0-100 mm). High values indicated good aesthetics. Necessity for further treatment was also measured by a VAS (0-100 mm). High values indicated high perceived need for further treatment. The professionals rated facial aesthetics significantly lower and had a lower perception of need for further treatment than the raters with and without a cleft. The laypeople with a cleft rated facial aesthetics significantly higher and had a lower perceived need for further treatment than laypeople without a cleft. The non-surgical professionals rated facial aesthetics significantly lower and had a lower perceived need for further treatment than the surgical professionals. Differences exist in the facial aesthetics ratings and perceived need for further surgery between professionals and laypeople with and without a cleft. This should be considered when managing cleft treatment expectations.

Paediatric sleep-disordered breathing due to upper airway obstruction in the orthodontic setting: a review.

The essential feature of paediatric sleep-disordered breathing (SDB) is increased upper airway resistance during sleep presenting clinically as snoring. Paediatric SDB is a continuum ranging from primary snoring (PS), which is not associated with gas exchange abnormalities or significant sleep fragmentation, to obstructive sleep apnoea (OSA) with complete upper airway obstruction, hypoxaemia, and obstructive hypoventilation. Adenotonsillar hypertrophy, obesity and craniofacial disharmonies are important predisposing factors in the development and progression of paediatric SDB. Clinical symptoms are significant and domains affected include behaviour, neurocognition, cardiovascular morbidity and quality of life. Overnight polysomnography is the current diagnostic gold standard method to assess SDB severity while adenotonsillectomy is the recommended first line of treatment. Other treatments for managing paediatric SDB include nasal continuous airway pressure, the administration of nasal steroids, dentofacial orthopaedic treatment and surgery. However, there are insufficient long-term efficacy data using dentofacial orthopaedics to treat paediatric SDB. Further studies are warranted to define the characteristics of patients who may benefit most from orthodontic treatment.

The effects of hypothermia and L-arginine on skeletal muscle function in ischemia-reperfusion injury.

OBJECTIVES: Ischemia-reperfusion (I/R) injury can have detrimental effects on skeletal muscle. We have shown that vessel permeability can be minimized in a hypothermic setting and also by administering the nitric oxide synthase (NOS) stimulator, L-arginine, at physiologic temperatures. The purpose of this study was to examine and compare skeletal muscle contractility after an I/R insult during hypothermic conditions, warm conditions, and also with the administration of L-arginine at physiologic temperatures. We hypothesized that hypothermia and L-arginine administration will also demonstrate protective effects to skeletal muscle contractility. METHODS: Using Sprague-Dawley rats, the extensor digitorum longus muscle was rotated on its vascular pedicle to a thermo-controlled stage. Ischemia was established using an atraumatic femoral artery tourniquet. Reperfusion was performed under control and experimental conditions including local hypothermia and intravenous L-arginine. After harvesting experimental muscles, contractility was then quantified by using a tissue bath stimulator with force transducers. RESULTS: Warm reperfusion resulted in marked decrease in muscle contractility compared with sham animals. Local hypothermia showed statistically significant preservation of contractility compared with the sham group. This protective effect was recapitulated by the application of NOS inducers (L-arginine) at warm conditions. CONCLUSIONS: These findings demonstrate that hypothermia and L-arginine are protective of skeletal muscle contractility after an I/R injury. The results presented may have profound effects on future therapeutic recommendations and suggest possible pathways for clinical intervention to modulate I/R injury, which is commonplace in orthopaedic trauma and reconstructive surgery.

A pharmacodynamic investigation into the efficacy of osteoprotegerin during aseptic inflammation.

BACKGROUND: Osteoprotegerin (OPG), as an osteoclast antagonist, limits mineralised tissue resorption under physiological conditions. Previous work investigating OPG in a rat periodontal ligament (PDL) ankylosis model found no inhibitory effect on osteoclasts when OPG was administered at a dosage of 2.5mg/kg. AIMS: The object of this study was to determine whether dosages higher than 2.5 mg/kg of OPG were required to limit osteoclastic activity in an aseptic inflammatory model in rats. MATERIALS AND METHODS: Dry ice was applied for 15 minutes to the upper right first molar crown of eighteen, 8-week-old, male Sprague-Dawley rats. Three groups of 3 were injected with OPG at dosages of 2.5, 5.0 and 7.5 mg/kg of body weight immediately following the thermal insult. After 7 days, the rats were sacrificed and each maxilla processed for histological examination and stained for osteoclastic activity using tartrate-resistant acid phosphatase (TRAP). Osteoclast population numbers were estimated via light microscopy and results were analysed using a comparative mixed model statistical analysis. RESULTS: Results showed OPG inhibited osteoclastic activity in a dose-dependent manner. From 2.5 mg/kg to 7.5 mg/kg, osteoclast populations were linearly reduced by 39.78% (p < 0.05). OPG did not appear to affect the inflammatory process and had varied efficacy in different regions of individual teeth. CONCLUSION: Although osteoclastic activity reduced, it was not completely eliminated, perhaps because dosages were still inadequate, or additional factors might influence OPG and osteoclast activation in the aseptic inflammatory model.

General health-related quality of life and oral health impact among Australians with cleft compared with population norms; age and gender differences.

OBJECTIVE: To evaluate general health-related quality of life (HRQoL) and oral health impact among adults treated for cleft to determine age and gender differences, and to compare against population norms. DESIGN: Cross-sectional prospective study. PARTICIPANTS/SETTING: Nonsyndromic cleft patients treated by the Australian Craniofacial Unit from 1975 to 2009 were recruited (n  =  112). Response rate was 79% (n  =  88). Main outcome measures : HRQoL was measured by the Short Form (SF)-36 questionnaire. Oral health impact was measured by the Oral Health Impact Profile (OHIP)-14 questionnaire. State-based and national norms were used for comparative purposes. RESULTS: There were no significant age or sex differences in the cleft sample's SF-36 and OHIP-14 scores. When compared against South Australian 2002 state-level norms, cleft participants scored higher on physical function and physical role function but lower on vitality and mental health. The prevalence of having experienced one or more of OHIP-14 items "fairly often" or "very often" was 2.7 times higher than national-level estimates, while extent was 2.8 times and severity 1.7 times higher. CONCLUSIONS: The oral health impact among cleft patients included in our study was poor compared with population-level estimates. The HRQoL showed mixed results, with the vitality and mental health components being poorer in the cleft group compared with population-level estimates. These results indicate that treatment for orofacial clefting does not entirely remove the factors contributing to poor HRQoL and oral health.

Masseter length determines muscle spindle reflex excitability during jaw-closing movements.

INTRODUCTION: The masticatory muscles are considered to be important determinants of facial form, but little is known of the muscle spindle reflex characteristics and their relationship, if any, to face height. The aim of this study was to determine whether spindle reflexes, evoked by mechanical stimulation of an incisor and recorded on the masseter muscle, correlated with different facial patterns. METHODS: Twenty-eight adult volunteers (16 women; ages, 19-38 years) underwent 2-N tap stimuli to their maxillary left central incisor during simulated mastication. Reflexes were recorded during local anesthesia of the stimulated tooth to eliminate the contribution from periodontal mechanoreceptors. Surface electromyograms of the reflex responses of the jaw muscles to these taps were recorded via bipolar electrodes on the masseter muscle and interpreted by using spike-triggered averaging of the surface electromyograms. Lateral cephalometric analysis was carried out with software (version 10.5, Dolphin, Los Angeles, Calif; and Mona Lisa, Canberra, Australia). RESULTS: Two-newton tooth taps produced principally excitatory reflex responses beginning at 17 ms poststimulus. Correlation analysis showed a significant relationship between these muscle spindle reflexes and facial heights: specifically, shorter face heights were associated with stronger spindle reflexes. This correlation was strongest between the derived measure of masseter length and the spindle reflex strength during jaw closure (r = -0.49, P = 0.008). CONCLUSIONS: These results suggest that a similar muscle spindle stimulus will generate a stronger reflex activation in the jaw muscles of patients with shorter faces compared with those with longer faces. This finding might help to explain the higher incidence of clenching or bruxism in those with short faces and also might, in the future, influence the design of orthodontic appliances and dental prostheses.

The presence of TNF-alpha and TNFR1 in aseptic root resorption. A preliminary study.

BACKGROUND: It is hypothesised that osteoprotegerin (OPG), as an osteoclast antagonist, may offer molecular control over the process of orthodontic root resorption. Previous work investigating OPG in a rat periodontal ligament (PDL) ankylosis model found no inhibitory effect on osteoclasts and odontoclasts when given at a recommended dosage of 2.5 mg/kg. It was considered that traumatically-induced PDL inflammation produces mediators and cytokines with the ability to stimulate clast cell differentiation and counter the effects of OPG. AIMS: The present study investigated the presence of Tumour Necrosis Factor Alpha (TNF-alpha) and its receptor Tumour Necrosis Factor Receptor 1 (TNFR1) in a PDL sterile inflammatory model. METHODS: Dry ice was applied for 15 minutes to the upper right first molar crown of eighteen, 8-week-old, male Sprague-Dawley rats of which 9 were injected with OPG at a dose of 2.5 mg/kg of body weight at the time of freezing. After 7 days, the rats were sacrificed and each maxilla processed for immunohistochemical identification of TNF-alpha and TNFR1. RESULTS: Results showed the presence of root resorption in varying amounts and locations in both experimental and control rats. Reparative processes appeared greater in the OPG-treated rats, often with the presence of an ankylotic union. Immunolabelling showed the presence of TNF-alpha and TNFR1 in the sterile inflammation located mainly in the interradicular PDL area. More definitive labelling appeared in OPG-treated rats. CONCLUSION: The results indicated that TNF-alpha, and its receptor TNFR1, by their presence, may modify OPG effectiveness by offering an alternative pathway for osteoclast formation, which counters the anti-resorptive effects of OPG.

MicroRNAs: master regulators of ethanol abuse and toxicity?

Ethanol exerts complex effects on human physiology and health. Ethanol is not only addictive, but it is also a fetal teratogen, an adult neurotoxin, and an etiologic agent in hepatic and cardiovascular disease, inflammation, bone loss, and fracture susceptibility. A large number of genes and signaling mechanisms have been implicated in ethanol's deleterious effects leading to the suggestion that ethanol is a "dirty drug." An important question is, are there cellular "master-switches" that can explain these pleiotropic effects of ethanol? MicroRNAs (miRNAs) have been recently identified as master regulators of the cellular transcriptome and proteome. miRNAs play an increasingly appreciated and crucial role in shaping the differentiation and function of tissues and organs in both health and disease. This critical review discusses new evidence showing that ethanol-sensitive miRNAs are indeed regulatory master-switches. More specifically, miRNAs control the development of tolerance, a crucial component of ethanol addiction. Other drugs of abuse also target some ethanol-sensitive miRNAs suggesting that common biochemical mechanisms underlie addiction. This review also discusses evidence that miRNAs mediate several ethanol pathologies, including disruption of neural stem cell proliferation and differentiation in the exposed fetus, gut leakiness that contributes to endotoxemia and alcoholic liver disease, and possibly also hepatocellular carcinomas and other gastrointestinal cancers. Finally, this review provides a perspective on emerging investigations into potential roles of miRNAs as mediators of ethanol's effects on inflammation and fracture healing, as well as the potential for miRNAs as diagnostic biomarkers and as targets for therapeutic interventions for alcohol-related disorders.

Immunohistochemical detection of nerve growth factor and its receptors in the rat periodontal ligament during tooth movement.

OBJECTIVES: Nerve growth factor (NGF) and its receptors, p75 and tyrosine receptor kinase A (Trk A), have been shown to increase following trauma. The aims of this study were to examine changes in the detection of NGF and its receptors during orthodontic tooth movement in the rat, and the effects of anti-NGF on these changes. DESIGN: Orthodontic separators were placed between the right maxillary first and second molars of Sprague-Dawley rats which were equally divided into two groups. Animals from the second group were injected with anti-NGF. The left sides served as controls, and animals were sacrificed at 0, 3, 7 and 14 days. RESULTS: Results of immunohistochemical localisation for p75, Trk A, calcitonin gene-related peptide (CGRP) and NGF showed staining intensity increased at day 3, with a peak at day 7 and decreasing intensity at day 14. Anti-NGF injected animals showed reduced staining at all observation periods. CONCLUSION: Data suggest that orthodontic injury induces NGF production, leading to sprouting and invasion by CGRP-positive nerve fibers and that injection of anti-NGF reduces NGF tissue levels and prevents innervation by CGRP-positive fibers.