Joseph S. Antoun

Long-term remineralizing effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on early caries lesions in vivo: A systematic review

OBJECTIVE To assess the long-term (>3 months) remineralizing effect of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on early caries lesions in vivo. DATA SOURCES PubMed, Web of Science, Embase, Cochrane-Central, Science Direct, CBM, and CNKI were searched up to April 2013. Only articles in English and Chinese were included. Grey literature was also searched. Randomized or quasi-randomized clinical trials in which CPP-ACP was delivered by any method were considered. All relevant studies underwent two independent reviews. STUDY SELECTION Of the 738 studies screened, 83 studies were reviewed and eight selected for inclusion in the final sample. The follow-up period of the studies included varied from 3 to 24 months. The long-term remineralizing effect of CPP-ACP in vivo was demonstrated in comparison with placebo in randomized controlled trial. However, there is conflicting evidence regarding the clinical efficacy of CPP-ACP when used in conjunction with fluoride toothpastes. No specific side effect related to CPP-ACP usage was found. CONCLUSIONS CPP-ACP has a long-term remineralizing effect on early caries lesions in comparison with placebo, although this does not appear to be significantly different from that of fluorides. The advantage of using CPP-ACP as a supplement to fluoride-containing products is still unclear. High-quality, well-designed clinical studies in this area are still required before definitive recommendations can be made. CLINICAL SIGNIFICANCE CPP-ACP is a promising remineralizing agent with a significant remineralizing effect that has been demonstrated in both in vivo and in vitro studies. The evidence to support its synergistic effect with fluoride is insufficient based on the current existing long-term human randomized controlled trials.

Neck and shoulder muscle activity of orthodontists in natural environments

Work related musculoskeletal disorders (WMSDs) are common among dentists and possibly caused by prolonged static load. The aim of this study was to assess the contraction pattern of neck and shoulder muscles of orthodontists in natural environments. Electromyographic (EMG) activity of right sternocleidomastoid and trapezius muscles were recorded by means of portable recorders in eight orthodontists during working conditions, and both active and resting non-working conditions. Recordings were analysed in terms of contraction episode (CE) count, amplitude, and duration. The sternocleidomastoid and trapezius muscles contracted about 40-70times per hour in the natural environment. Their EMG activity pattern mainly consisted of short-lasting, low-amplitude CEs. The counts and amplitude of sternocleidomastoid CEs did not differ across vocational and non-vocational conditions. The number and amplitude of trapezius CEs were slightly but significantly higher during the vocational condition. There were highly significant (p<0.001) differences in duration of CEs across conditions, with two to threefold increase in the average duration of trapezius muscle contractions found in the vocational setting. During orthodontic work, operators commonly hold muscular contractions for significantly longer periods than are encountered in non-vocational settings. This behaviour may be associated causally with the increases seen in WMSDs through proposed pathophysiological mechanisms occurring at the motor unit level. Our findings may also be valid for other occupations characterised by seated static postures with precision hand and wrist movements.

Oral health–related quality of life changes in standard, cleft, and surgery patients after orthodontic treatment

INTRODUCTION The purpose of this study was to investigate the effect of orthodontic treatment on oral health-related quality of life (OHRQoL) in groups of standard patients with severe malocclusions; cleft lip, cleft palate, or cleft lip and palate patients; and orthognathic surgery patients. METHODS The study sample consisted of 83 consecutive patients undergoing treatment at the orthodontic unit of Christchurch Hospital, Christchurch, New Zealand, divided into 3 groups: 30 adolescents with severe malocclusions; 24 adolescents with cleft lip, cleft palate, or cleft lip and palate; and 29 adults with severe skeletal discrepancies requiring both orthognathic surgery and orthodontic treatment. Each patient completed the Short Form of the Oral Health Impact Profile (OHIP-14) questionnaire before and after orthodontic treatment. RESULTS The baseline OHIP-14 subscale scores among the 3 study groups were significantly different, with the surgery patients having nearly twice the OHIP-14 scores of the other 2 groups for nearly half of the items (P <0.05). The surgery patients experienced the greatest reduction in OHIP-14 scores (ie, improvement in OHRQoL), with the largest effect sizes reported for the psychological discomfort (+2.73) and disability (+2.65) domains. The group with clefts experienced the smallest changes in OHIP-14 scores across all 7 domains (-0.03 to +0.63). After adjusting for age and sex, the surgical patients had a significantly greater reduction in pretreatment OHIP-14 scores than did the standard and the cleft patients (P <0.01). CONCLUSIONS The effect of orthodontic treatment on OHRQoL varies for different patient groups even after adjusting for age and sex. The greatest improvement in OHRQoL occurred in adults with a need for orthognathic surgery, whereas the least improvement seemed to occur in adolescents with cleft lip, cleft palate, or cleft lip and palate.

The effect of incremental lower lip advancement on oral pressure and EMG activity of the lower lip.

OBJECTIVES During orthodontic arch expansion, the teeth are displaced against the perioral soft tissues. This can affect the equilibrium of forces that are thought to act on teeth, with consequent implications for long-term stability. The aim of this study was to investigate the effect of incremental lower lip advancement on intraoral pressure and electromyographic (EMG) activity of the lower lip. MATERIALS AND METHODS Intraoral pressure and EMG activity was measured in 10 participants (2 males, 8 females; 22 years ± 7 months) as the lower lip was incrementally advanced using three custom-made vacuum-formed stents of differing labial thicknesses (0.5, 2.5, and 4.5 mm). A task paradigm including at rest recordings and maximal voluntary contraction was completed for each tray. RESULTS Resting lip pressure generated increased as the lower lip was advanced (P < 0.001). The EMG activity of the lower lip increased significantly (P < 0.001) only once the lip was advanced from 2.5 to 4.5 mm. For the pressure recordings, the response to incremental lip advancement showed considerable individual variation. CONCLUSIONS These findings suggest that the initial pressure increase on the lower incisors was mostly likely due to the inherent viscoelastic properties of the lower lip, while the pressure increase between the 2.5 and 4.5 mm advancement was due to increased muscle activity. Each individual also responded to lower lip advancement in a different yet subject-specific manner.

Effect of orthodontic treatment on the periodontal tissues

Reduced periodontal support is a challenge that clinicians often face during rehabilitation of compromised dentition. The close and intricate relationship between the periodontal tissues and the processes of tooth movement suggest that adjunct orthodontic therapy may play an important role in overcoming these problems. On the other hand, excessive movement of teeth beyond the anatomic boundaries of the alveolar process is commonly believed to contribute to further destruction of the periodontal tissues. This review evaluates the clinical effects of various orthodontic tooth movements on the surrounding periodontal soft tissues and alveolar bone. Another objective was to identify possible patient and treatment-related factors that may influence the response of periodontal tissue to specific orthodontic treatments. Particular emphasis is placed on specific tooth movements, such as extrusion, intrusion, space closure and arch expansion. Limitations of current research are also highlighted and discussed.

Hypodontia: An Update on Its Etiology, Classification, and Clinical Management

Hypodontia, or tooth agenesis, is the most prevalent craniofacial malformation in humans. It may occur as part of a recognised genetic syndrome or as a nonsyndromic isolated trait. Excluding third molars, the reported prevalence of hypodontia ranges from 1.6 to 6.9%, depending on the population studied. Most affected individuals lack only one or two teeth, with permanent second premolars and upper lateral incisors the most likely to be missing. Both environmental and genetic factors are involved in the aetiology of hypodontia, with the latter playing a more significant role. Hypodontia individuals often present a significant clinical challenge for orthodontists because, in a number of cases, the treatment time is prolonged and the treatment outcome may be compromised. Hence, the identification of genetic and environmental factors may be particularly useful in the early prediction of this condition and the development of prevention strategies and novel treatments in the future.

Maternal Smoking during Pregnancy Is Associated with Offspring Hypodontia

Little is known about environmental risk factors for hypodontia. The objective of this study was to investigate the association between hypodontia and common environmental risk factors, such as maternal smoking and alcohol and caffeine consumption during pregnancy. Eighty-nine hypodontia cases with 1 or more missing permanent lateral incisors and/or 1 or more missing premolars were enrolled in this clinic-based case-control study. Some 253 controls with no missing teeth were frequency matched to cases by age and sex. Hypodontia was diagnosed using panoramic radiographs. Sociodemographic data were collected from both the participants and their mothers, with maternal self-reported active and passive smoking, as well as alcohol and caffeine consumption during pregnancy, assessed by a questionnaire. Odds ratios (ORs) and their 95% confidence intervals (CIs) were calculated with logistic regression to assess the strength of association between risk factors and hypodontia. OR estimates were then adjusted for possible confounders, such as maternal age at delivery, sex and gestational age of the child, and household socioeconomic background. Significant associations were found between hypodontia and maternal cigarette use during pregnancy, as well as the number of cigarettes smoked per day. The consumption of 10 or more cigarettes per day during pregnancy was associated with greater odds of having a child with hypodontia (adjusted OR, 4.18; 95% CI, 1.48–11.80; P = 0.007). Observed associations between hypodontia, second-hand smoke, and alcohol and caffeine consumption were not statistically significant. Maternal smoking during pregnancy is associated with hypodontia. Larger samples and prospective observational study designs, however, are needed to investigate this association further.

Impact of skeletal divergence on oral health-related quality of life and self-reported jaw function

Objective To investigate the differences in oral health-related quality of life (OHRQoL) and self-reported jaw function between patients with hyperdivergent and normodivergent facial types. Methods Eighty patients with a distinctively hyperdivergent facial type (mandibular plane angle greater than 2 standard deviations, or 42°) and 80 controls were individually matched according to age, sex, ethnicity, and treatment stage. Data were collected using self-report questionnaires such as the Oral Health Impact Profile (OHIP-14) and Jaw Functional Limitation Scale (JFLS-8). Results The mean age of the patients was 17.2 ± 4.6 years (range, 12–9 years), with most (65.0%) being female and of New Zealand European origin (91.3%). Individuals with hyperdivergent facial types had higher overall and social domain scores on the OHIP-14 (p < 0.05) than did the ones with normodivergent facial types. However, the intergroup differences in JFLS-8 scores were not significant (p > 0.05). Conclusions Jaw function appears to be similar in individuals with hyperdivergent and normodivergent facial morphologies. However, those with hyperdivergent facial types are more likely to self-report poorer OHRQoL than are those with normal faces, especially in relation to social aspects.

Long-term changes in oral health-related quality of life of standard, cleft, and surgery patients after orthodontic treatment: A longitudinal study

Introduction The aim of this study was to assess long‐term changes and describe the trajectories of oral health‐related quality of life (OHRQoL) in a cohort of cleft, surgery, and standard patients who received orthodontic treatment. Methods Standard (n = 16), cleft (n = 19), and orthognathic surgery (n = 22) patients completed the short‐form of the Oral Health Impact Profile (OHIP‐14) before treatment, immediately posttreatment, and approximately 5 years posttreatment. Results An overall reduction in OHIP‐14 scores (improvement in OHRQoL) occurred after orthodontic treatment; however, this was only significant for the surgery and standard groups (P <0.05). The total OHIP‐14 score increased significantly from posttreatment to 5 years follow‐up for all 3 study groups (P <0.05). Relative to pretreatment, however, there were significant reductions in total OHIP‐14 scores at 5 years posttreatment in the surgery group (−57.4%; P <0.05), but not in the standard sample (−24.2%; P >0.05). By contrast, the OHIP‐14 score in the cleft group increased but not significantly (40.2%; P >0.05). Using a mixed model analysis, a significant interaction was detected between patient group and time (ie, study time point) (F = 6.0; P <0.0001), after adjusting for age and sex. Conclusions Distinct patient groups showed different OHRQoL trajectories after orthodontic treatment. Treatment‐related improvements in OHRQoL are maintained over time for surgery patients, but not for those with standard malocclusions and orofacial clefts. HighlightsDifferent patient groups show distinct OHRQoL trajectories after orthodontic treatment.Orthognathic surgery patients experience large and sustained improvements in OHRQoL.Patients with clefting and standard malocclusion do not experience OHRQoL changes in the long term.In cleft patients, the perceived need for more surgery is associated with reduced OHRQoL.

Self‐reported oral behaviour habits in hyperdivergent and normodivergent facial types

The relationship between facial morphology and jaw function remains controversial. The purpose of this study was to investigate differences in self-reported oral behaviour habits between individuals with normodivergent and hyperdivergent facial types. Some 80 cases and controls were individually matched on age, sex ethnicity and treatment stage. The participants were recruited from an orthodontic clinic, and included both adolescents and adults. Habitual oral activity was assessed using the Oral Behaviour Checklist (OBC) based on their experiences in the past 4 weeks. Univariate and bivariate analyses were performed. The sample had a mean age of 17·2 years (SD = 4·6; range = 12-49 years), and was predominantly female (65·0%) and of New Zealand European origin (91·3%). The prevalence of reporting one or more frequently performed habitual muscular behaviour in either study group was over 85% (P > 0·05). There was no difference in total OBC score between the hyperdivergent (25·6; SD: 9·0) and normodivergent group (25·3; SD: 9·9). Moreover, there was no difference in the prevalence of either nocturnal or daytime oral behaviours between the two groups. While this study did not include any objective measures of functional or habitual activity, we found no differences in self-reported oral behaviour habits between normodivergent and hyperdivergent individuals. The findings do not support an association between vertical facial form and habitual muscular activity.