Adjunctive use of hyaluronic acid in the treatment of gingival recessions: a systematic review and meta-analysis.

OBJECTIVES: To explore the efficacy of Hyaluronic acid as an adjunctive in treatment of gingival recessions (GR). MATERIALS AND METHODS: A systematic literature search was performed in several electronic databases, including Medline/ PubMed, Embase, CENTRAL and LILACS. Recession improvement was evaluated through multiple outcome variables. The Cochrane Risk of Bias tool and the ROBINS-I tool were used to assess the quality of the included trials. Weighted Mean Differences (WMDs) and 95% confidence intervals (CIs) between test and control sites were estimated through meta-analysis using a random-effect model for the amount of Relative Root Coverage (RRC). RESULTS: A total of 3 randomised studies were deemed as eligible for inclusion. Their data were also used for pooling the effect estimates. Overall analysis of RRC (3 studies) presented a WMD of 7.49% (p = 0.42; 95% CIs -10.88, 25.86) in favour of adjunctive use of hyaluronic acid during Coronally Advanced Flap (CAF) technique, although statistical significance was not reached. Statistical heterogeneity was found to be high (I2 = 80%). CONCLUSIONS: Within their limitations, the present data indicate that the local application of Hyaluronic acid does not lead to additional clinical benefits when used as an adjunctive to the treatment of GR with CAF. However, due to the high heterogeneity among the studies, additional well-designed RCTs are needed to provide further evidence on this clinical indication for the use of Hyaluronic acid. CLINICAL RELEVANCE: In the frame of the current review, the adjunctive use of Hyaluronic acid does not additionally improve the clinical outcomes obtained during treatment of GR with CAF.

Assessment of gingival translucency at the mandibular incisors with two different probing systems. A cross sectional study.

OBJECTIVES: Increasing evidence indicates that the thickness of periodontal soft tissues plays an important role in various clinical scenarios, thus pointing to the need of further clinical research in this area. Aim of the present study was to assess gingival thickness at the mandibular incisors by translucency judgement with two different probes and to validate if these methods are comparable and applicable as diagnostic tools. MATERIALS AND METHODS: A total of 200 participants were included; gingival tissue thickness was measured by judging probe translucency at both central mandibular incisors, mid-facially on the buccal aspect of each tooth using a standard periodontal probe and a set of color-coded probe, each with a different color at the tip, i.e. Colorvue Biotype Probe (CBP). Frequencies and relative frequencies were calculated for probe visibility. Agreement between the standard periodontal probe and the CBP was evaluated via the kappa statistic. RESULTS: When the periodontal probe was visible, the frequency of CBP being visible was very high. Kappa statistic for the agreement between the standard periodontal probe and the CBP was 0.198 (71.5% agreement; p-value < 0.001) for tooth 41 and 0.311 (74.0% agreement; p-value < 0.001) for tooth 31, indicating a positive association of the two methods. CONCLUSIONS: An agreement that reached 74% was estimated between the standard periodontal probe and the color-coded probe at central mandibular incisors.  CLINICAL RELEVANCE: In the context of the present study, the two methods of evaluating gingival thickness seem to produce comparable measurements with a substantial agreement. However, in the 1/4 of the cases, the visibility of the color-coded probe could not assist in the categorization of the gingival phenotype.

Distribution of initial caries lesions in relation to fixed orthodontic therapy. A systematic review and meta-analysis.

BACKGROUND: Initial caries lesion (ICLs) adjacent to orthodontic brackets are the most common side effect of orthodontic treatment with fixed appliances. The reported prevalence is uncertain and varies considerably across studies, from 27% to 97%. OBJECTIVES: This paper was designed to evaluate and synthesize the available evidence on the prevalence and incidence rates of ICLs in relation to orthodontic treatment. Selection criteria: The review (Prospero protocol CRD42023412952) included randomized and non-randomized clinical trials of interventions, cohort studies, and cross-sectional studies, published after 1990 on the prevalence or incidence of ICLs during or after orthodontic treatment with fixed appliances. Search methods: Pubmed, Scopus, and Embase databases were searched from 1990 until 01 May 2023. The risk of bias assessment was performed with RoB 2 and ROBINS-I tool and the Joanna Briggs Institute Critical Appraisal Checklist. Data collection and analysis: The proportion of individuals with ICLs, reported as the number/percentage of individuals/teeth with ICLs or mean number of ICLs per subject, were used to synthesize results. RESULTS: The search yielded a total of 468 papers; 21 studies were included in the systematic review, 2 of which were not included in the meta-analysis. The prevalence rate [95%CI] of ICLs was 0.57% [0.48; 0.65] in 1448 patients, 0.22% [0.14; 0.33] in 11583 teeth, with a mean number of lesions equal to 2.24 [1.79; 2.70] in 484 patients evaluated. The incidence rate of new carious lesions developed during orthodontic treatment was 0.48% [0.33; 0.63] in 533 patients, 0.15% [0.08; 0.26] in 1890 teeth with a mean number of ICLs equal to 2.29 [1.12; 3.46] in 208 patients evaluated. LIMITATIONS: Although the high number of included studies and the overall good quality, there was a significant heterogeneity in the collected data. CONCLUSION: The prevalence and incidence rates of ICLs in subjects undergoing orthodontic treatment are quite high and raise some concerns in terms of risk assessment of orthodontic treatment. ICLs represent an alarming challenge for both patients and professionals. Effective caries prevention strategies during treatment need to be considered and implemented where appropriate.

The role of calcium in the prevention of erosive tooth wear: a systematic review and meta-analysis.

OBJECTIVES: The loss of hard dental tissue due to recurrent acid challenges and mechanical stresses without bacterial involvement is known as erosive tooth wear (ETW). Many studies in the literature have concentrated on variables that may affect the ETW process and prevent its occurrence or reduce its advancement. However, to date, no previous systematic review has evaluated the role of calcium in preventing ETW. Therefore, the purpose of the present systematic review was to review and critically appraise the scientific evidence regarding the role of calcium formulations in the prevention of ETW. METHODS: The review protocol was registered in the PROSPERO international prospective register of systematic reviews (Ref: CRD42021229819). A literature search was conducted in electronic databases to identify in situ randomized controlled trials evaluating the prevention of ETW following the application of calcium formulations. The outcomes studied included mean enamel loss, surface microhardness, surface roughness, mean erosion/softening depth, mineral loss/precipitation and remineralization. Study characteristics and outcomes of included studies were summarized. Cochrane's risk-of-bias tool 2.0 was used to assess the quality of eligible studies, and meta-analysis using a random effects model was performed. RESULTS: The search retrieved 869 studies of which 21 were considered eligible. Regarding the results of the quality assessment for potential risk of bias in all included studies, overall, 5 studies were considered as being at low risk, another 12 at unclear risk and 4 at high risk of bias. The findings of the studies showed that the addition of calcium in juice drinks led to reduced enamel loss, with blackcurrant juice presenting 2.6 times statistically significant less enamel loss compared to orange juice (p = 0.0001, I2 = 89%). No statistically significant difference in mean surface microhardness of eroded enamel was recorded between chewing gum with or without casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) (p = 0.31, I2 = 71%). Contradictory were the results regarding the effect of milk and CPP-ACP pastes on prevention of ETW. CONCLUSIONS: Calcium formulations play an important role in ETW prevention, mainly through their addition to acidic drinks.

Impact of fixed orthodontic appliances on blood count and high-sensitivity C-reactive protein levels: A prospective cohort study.

INTRODUCTION: The aim was to elucidate the magnitude of alterations in systemic blood counts in healthy patients during the first 14 days after fixed orthodontic appliance placement. METHODS: This prospective cohort study consecutively included 35 White Caucasian patients starting orthodontic treatment with fixed appliances. The mean age was 24.48 ± 6.68 years. All patients were physically and periodontally healthy. Blood samples were collected at 3 time points: (1) baseline (exactly before the placement of appliances), (2) 5 days after bonding, and (3) 14 days after baseline. Whole blood and erythrocyte sedimentation rates were analyzed in automated hematology and erythrocyte sedimentation rate analyzer. Serum high-sensitivity C-reactive protein levels were measured by the nephelometric method. Standardized sample handling and patient preparation procedures were adopted to reduce preanalytical variability. RESULTS: A total of 105 samples were analyzed. All clinical and orthodontic procedures were performed without complications or side effects during the study period. All laboratory procedures were performed per protocol. Significantly lower white blood cell counts were detected 5 days after bracket bonding, compared with baseline (P <0.05). Hemoglobin levels were lower at 14 days than baseline (P <0.05). No other significant shifts or alteration patterns were observed over time. CONCLUSIONS: Orthodontic fixed appliances led to a limited and transient change in white blood cell counts and hemoglobin levels during the first days after bracket placement. The fluctuation of high-sensitivity C-reactive protein levels was not significant, demonstrating a lack of association between systemic inflammation and orthodontic treatment.

Short-term efficacy of caries resin infiltration during treatment with orthodontic fixed appliances. A randomized controlled trial.

OBJECTIVES: Objective of this trial was to assess the masking results in initial caries lesions (ICL) that were resin infiltrated during fixed orthodontic treatment in comparison to contralateral teeth that were fluoridated only. TRIAL DESIGN: A randomized, controlled, split-mouth trial. METHODS: Adolescent patients (age range: 12-18 years) with fixed orthodontic appliances who had developed ICL [ICDAS 1 or 2 (International Caries Detection and Assessment System)] during orthodontic treatment were consecutively recruited and randomly assigned to either resin infiltration (Icon) with up to 3 etching procedures (Inf) or to a fluoride varnish (Tiefenfluorid) (FV). Both interventions were performed according to the manufacturer's recommendations. Outcome assessors were blinded to the applied intervention. Primary and secondary outcomes included the evaluation of the appearance of the ICL before (T0) and 1 week after (T1) treatment by digital photographs (ΔE), laser fluorescence readings (DD), and ICDAS scores. BLINDING: Due to the treatment nature neither the operators nor the patients could be blinded. However, outcome assessors and the statistician were blinded. RESULTS: Fifteen patients (9 female) with 60 ICL were included (mean age: 14.6 years). At baseline FV and Inf did not differ significantly in ΔE (median ΔE0,T (25th/75th percentiles):10.7(9.1/20.9): ΔE0,I:13.4(10.3/18.5); P = 0.469), DD (P = 0.867) and ICDAS (P = 0.521). One-week after treatment (T1) ΔE values (P < 0.001), DD values (P < 0.001), and ICDAS scores (P = 0.014) for Inf were significantly reduced, whereas ΔE values (P = 0.125) and ICDAS scores (P = 0.073) for FV remained unchanged. LIMITATION: Natural remineralizing in the standard interventional control group cannot be observed yet, since up to 6 months are needed to naturally remineralize ICL. CONCLUSIONS: Based on our short-term data, resin infiltration effectively masked ICL during treatment with fixed orthodontic appliances. Fluoridation was not able to immediately improve the visual appearance of ICL. Further longer-term assessment should focus not only on the aesthetic outcome, but also on the caries inhibitory effect of resin infiltration during treatment with fixed orthodontic appliances. TRIAL REGISTRATION: German Clinical Trials Register (DRKS-ID: DRKS00011797).

Effect of combined periodontal and orthodontic treatment of tilted molars and of teeth with intra-bony and furcation defects in stage-IV periodontitis patients: A systematic review.

AIM: To assess the effect of combined periodontal and orthodontic treatment (OT) in stage-IV periodontitis patients. MATERIALS AND METHODS: Three focused questions were addressed using the Population, Intervention, Comparison, Outcome, and Study Design criteria. Randomized controlled trials (RCTs), controlled clinical trials, follow-up studies, case series, and controlled/uncontrolled before/after studies were assessed for inclusion. Primary outcomes included mean changes in pocket probing depth (PPD) and clinical attachment level (CAL). Qualitative synthesis of results was performed and reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. RESULTS: Out of 916 records, 1 retrospective case series study reported the effect of OT of tilted molars, 2 RCTs and 10 prospective and 2 retrospective case series studies reported the effect of OT of treated intra-bony defects and 0 articles reported the effect of OT of treated furcation defects. Mean PPD changes were reported in 14 articles, and mean CAL changes were reported in 8 articles. Risk of bias was high in both included RCTs, critical in nine articles, and serious in four articles. No articles included patient-reported outcomes, and three articles reported harms/adverse effects. CONCLUSIONS: Evidence is limited by (i) the lack or low number of included studies, (ii) the apparent methodological and clinical heterogeneity, and (iii) the high risk of bias of the retrieved studies. No solid conclusions could be drawn concerning OT in stage-IV periodontitis patients with respect to tilted molars, teeth with treated intra-bony defects, and teeth with treated furcation defects.

Gingival thickness threshold and probe visibility through soft tissue: a cross-sectional study.

OBJECTIVES: The aim was to retrieve the threshold of gingival thickness (GT), where the attribute of gingival translucency through probe visibility was altered. METHODS: In 200 patients, the soft tissue thickness was evaluated at both central mandibular incisors using ultrasound quantification (USD). Additionally, probe visibility was determined using a standard periodontal probe (PB) (CPU 15 UNC, Hu-Friedy), inserted 1 mm deep into the gingival sulcus. Frequencies and relative frequencies were calculated. Repeatability analyses and receiver operating characteristics (ROC) were conducted to determine the USD cut-off point for probe visibility. RESULTS: Regression model indicated that the probe was not visible at a thickness of 0.82 mm for the mandibular left central incisor (95% CIs 0.77, 0.86) and became visible at a thickness of 0.69 mm (95% CIs 0.65, 0.72). The respective values for the mandibular right central incisor were 0.82 mm (95% CIs 0.77, 0.87) and 0.70 mm (0.68, 0.74). ROC analysis confirmed the retrieved regression results by indicating the best fitting balance for specificity and sensitivity at a thickness of 0.8 mm for both mandibular incisors. CONCLUSIONS: In the frame of the current study, the data revealed that gingiva becomes non-transparent at a thickness of approximately 0.8 mm. CLINICAL RELEVANCE: Probe visibility at mandibular incisors for the discrimination between thin and thick soft tissues was correlated with a gingival thickness of 0.8 mm and a high repeatability.

Enamel matrix derivative as adjunctive to non-surgical periodontal therapy: a systematic review and meta-analysis of randomized controlled trials.

OBJECTIVES: To assess the potential additional benefit of the local application of enamel matrix derivative (EMD) on the clinical outcomes following non-surgical periodontal therapy (NSPT) (steps 1 and 2 periodontal therapy). MATERIALS AND METHODS: A systematic literature search was performed in several electronic databases, including Medline/PubMed, Embase, The Cochrane Register of Central Trials (CENTRAL), LILACS, and grey literature. Only randomized controlled clinical trials (RCTs) were eligible for inclusion. Clinical attachment level (CAL) change (primary outcome), probing pocket depth (PPD), and bleeding on probing (BoP) reductions (secondary outcomes) were evaluated. The Cochrane Risk of Bias tool (RoB 2.0) was used to assess the quality of the included trials. Weighted mean differences (WMDs) and 95% confidence intervals (CIs) between test and control sites were estimated using a random-effect model for amount of mean CAL and PPD change. RESULTS: Six RCTs were included for the qualitative analysis, while data from 4 studies were used for meta-analysis. Overall analysis of CAL gain (3 studies) and PPD reduction (4 studies) presented WMD of 0.14 mm (p = 0.74; CI 95% - 0.66; 0.94) and 0.46 mm (p = 0.25; CI 95% - 0.33; 1.26) in favor of NSPT + EMD compared to NSPT alone respectively. Statistical heterogeneity was found to be high in both cases (I2 = 79% and 87%, respectively). CONCLUSIONS: Within their limitations, the present data indicate that the local application of EMD does not lead to additional clinical benefits after 3 to 12 months when used as an adjunctive to NSPT. However, due to the high heterogeneity among the studies, additional well-designed RCTs are needed to provide further evidence on this clinical indication for the use of EMD. CLINICAL RELEVANCE: The adjunctive use of EMD to NSPT does not seem to additionally improve the clinical outcomes obtained with NSPT alone.

Effect of the timing of second molar bonding on the duration of the mandibular arch levelling: a randomized clinical trial.

INTRODUCTION: This study investigated the effect of the timing of second molar bonding on the time required for the levelling of the mandibular dental arch. TRIAL DESIGN: Single-centre two-arm parallel randomized clinical trial using random permuted blocks. Allocation concealment was achieved through sealed envelopes. There was blinding in outcome assessment, but not of patient or operator. METHODS: Thirty-six patients (12-18 years old) with mild to moderate crowding and fully erupted mandibular second molars were assigned randomly (1:1 ratio) in two groups. Group A started fixed orthodontic treatment by bracket bonding in both jaws. Initial wire was 0.014" NiTi. Lower second molar tubes were bonded at the time of 0.016" x 0.022" NiTi wire placement. Group B was same as Group A, but second lower molars were bonded at the first appointment. Placement of the 0.017" x 0.025" stainless steel wire in the mandibular arch was considered the primary endpoint of the trial, indicating the completion of the levelling phase. The days required from bonding to the endpoint comprised the main outcome. Non-parametric statistics were applied. RESULTS: There were two dropouts in each group. The compared groups had similar baseline characteristics regarding age, sex, overjet, overbite, space in the dental arch, average Curve of Spee (CoS), and maximum CoS. Group A tended to require more days for levelling (median: 203 days) than Group B (median: 168 days). However, this difference was not statistically significant (P = 0.128). From the tested occlusal factors, only initial overjet was found to be moderately associated with the days required to complete levelling of the mandibular arch (r = 0.45, P = 0.009). CONCLUSIONS: In the frame of the current study, the duration of the levelling phase of orthodontic treatment with fixed appliances was not affected by the timing of second molar inclusion in the appliance. Future research could aim in cases with deep CoS to generalize the present findings and in larger sample sizes.

Bone turnover markers in gingival crevicular fluid and blood serum of patients with fixed orthodontic appliances.

AIM: Bone remodelling can be followed through the bone turnover markers (BTMs). Aim of the present study was to record the fluctuation of an osteoclastic and an osteoblastic BTM [C-terminal telopeptide of type I collagen (CTX) and N-terminal pro-peptide of type I pro-collagen (PINP), respectively] in both the gingival crevicular fluid (GCF) and the serum of orthodontic patients before and after the initial application of orthodontic forces. MATERIALS AND METHODS: Twenty-one Caucasian patients were prospectively evaluated. GCF and blood samples were collected in order to measure the selected biomarkers by ELISA at three time-points: exactly before, 5 days, and 14 days after bonding of the appliances. Standardized sample handling and patient preparation procedures were adopted in order to reduce pre-analytical variability. RESULTS: GCF and serum CTX levels were found to be independent of age, although higher in the serum of female subjects. PINP levels were found higher in the serum of patients ≥25 years old, as well as in the GCF of males. A positive correlation between serum and GCF baseline PINP levels was observed. LIMITATIONS: The effect of orthodontic treatment on bone remodelling might not be absolutely representative of the local bone microenvironment as the levels of the specific BTMs where measured within the GCF of the lower front teeth. CONCLUSIONS: This is the first time PINP and CTX have been evaluated in the GCF and serum of orthodontic patients with fixed appliances. No statistically significant alterations of CTX and PINP levels in the GCF and the serum of patients were recorded over time during the initial stages of orthodontic treatment.

The effects of fixed orthodontic retainers on periodontal health: A systematic review.

INTRODUCTION: The objective of this systematic review was to assess the available evidence in the literature for the effects of fixed orthodontic retainers on periodontal health. METHODS: The following databases were searched up to August 31, 2019: Medline, EMBASE, the Cochrane Oral Health Group's Trials Register, CENTRAL, ClinicalTrials.gov, the National Research Register, and Pro-Quest Dissertation Abstracts and Thesis database. Randomized controlled trials (RCTs), controlled clinical trials, cohort studies of prospective and retrospective design, and cross-sectional studies reporting on periodontal measurements of patients who received fixed retention after orthodontic treatment were eligible for inclusion. The quality of the included RCTs was assessed per the revised Cochrane risk of bias tool for randomized trials (RoB 2.0), whereas the risk of bias of the included cohort studies was assessed using the Risk Of Bias In Nonrandomized Studies of Interventions tool. A modified version of the Newcastle-Ottawa scale was used for cross-sectional studies. RESULTS: Eleven RCTs, 4 prospective cohort studies, 1 retrospective cohort study, and 13 cross-sectional studies fulfilled the inclusion criteria. The quality of evidence was low for most of the included studies. In contrast to the general consensus, 2 RCTs, 1 prospective cohort study, and 2 cross-sectional studies reported poorer periodontal conditions in the presence of a fixed retainer. The results of the included studies comparing different types of fixed retainers were heterogeneous. CONCLUSIONS: According to the currently available literature, orthodontic fixed retainers seem to be a retention strategy rather compatible with periodontal health, or at least not related to severe detrimental effects on the periodontium.

Social media and orthodontic treatment from the patient's perspective: a systematic review.

BACKGROUND: Social media are one of the most common and easily accessible ways of gaining information about orthodontic treatment. OBJECTIVE: The main objective of this study was to systematically search the literature and determine the various aspects of the interrelationship between social media and orthodontics from the patient's perspective. SEARCH METHODS: Electronic database searches of published and unpublished literature were performed. The reference lists of all eligible articles were hand-searched for additional studies. SELECTION CRITERIA: Randomized clinical trials (RCTs), prospective, retrospective, and cross-sectional studies were included. DATA COLLECTION AND ANALYSIS: Study selection, data extraction, and risk of bias assessment were performed individually and in duplicate by the first two authors. RESULTS: One RCT, three retrospective, and four cross-sectional studies were deemed as eligible for inclusion in this review. The studies included patient's statements in social media or results from questionnaires given to patients. The social media reported were with order of frequency: Twitter, YouTube, Facebook, Google+, Pinterest, and Instagram. The feelings the patients expressed seemed to be more positive than negative: enthusiasm, self-esteem and pleasure, excitement about the aesthetic result, excitement after braces removal but also antipathy, annoyances, reduced self-esteem, and impatience for removing mechanisms. In addition, one study referred to bullying through Twitter. LIMITATIONS: The high amount of heterogeneity precluded a valid interpretation of the results through pooled estimates. CONCLUSIONS AND IMPLICATIONS: This systematic review demonstrated that information about orthodontics, how the patient feels, and other psychosocial facets are spread through social media. It is intuitive that research relating to the effects and impact of orthodontic interventions should account not only for the physical impacts of treatment but also to encompass patient-centered outcomes. REGISTRATION: The protocol of this study was not registered in publicly assessable database. CONFLICTS OF INTEREST: None to declare.

Success of palatal implants or mini-screws placed median or paramedian for the reinforcement of anchorage during orthodontic treatment: a systematic review.

Objectives: To assess the failure rates of palatal implants and palatal mini-screws, independently and comparatively, used for supplementing anchorage during orthodontic treatment. Protocol and registration: The protocol was not registered prior to the study. This study was not registered in any publicly assessable database. Materials and methods: Screening for inclusion eligibility, quality assessment of studies, and data extraction was performed independently by two authors. The electronic databases MEDLINE, EMBASE, and CENTRAL, as well as unpublished literature, were searched with no restrictions on publication date or language using detailed strategies. The main outcome assessed was palatal implant or mini-screw failure. Randomized controlled trials were evaluated according to the Cochrane risk of bias tool. Prospective and retrospective studies were graded employing the adjusted predetermined criteria of Bondemark. Results: Twenty-seven studies satisfied the inclusion criteria. Four were RCTs of low risk of bias, 12 were prospective (2 low, 7 unclear, 3 high risk of bias) and 11 were retrospective studies (6 unclear, 5 high risk of bias). Only one retrospective study assessed both palatal implants and mini-screws. Seventeen studies, including the four RCTs, assessed solely palatal implants and nine studies palatal mini-screws. The median failure risk of palatal implants was 6.0 per cent (range: 0.0-26.1%) and of mini-screws 6.1 per cent (range: 0.0-33.3%). The median follow-up period was 17.9 months for palatal implants and 6 months for mini-screws. Limitations: Significant clinical and methodological heterogeneity among studies and highly variable outcomes. Conclusions: Both palatal implants and mini-screws have quite low failure rates that are also comparable, though the median follow-up period of palatal implants was quite larger. Therefore, in regular orthodontic cases, the choice between anchoring devices may rely on other factors, such as costs, patient comfort, personal preferences, familiarity with the device, and insertion procedures.

Maxillary distraction osteogenesis versus orthognathic surgery for cleft lip and palate patients.

BACKGROUND: Cleft lip and palate is one of the most common birth defects and can cause difficulties with feeding, speech and hearing, as well as psychosocial problems. Treatment of orofacial clefts is prolonged; it typically commences after birth and lasts until the child reaches adulthood or even into adulthood. Residual deformities, functional disturbances, or both, are frequently seen in adults with a repaired cleft. Conventional orthognathic surgery, such as Le Fort I osteotomy, is often performed for the correction of maxillary hypoplasia. An alternative intervention is distraction osteogenesis, which achieves bone lengthening by gradual mechanical distraction. This review is an update of the original version that was published in 2016. OBJECTIVES: To provide evidence regarding the effects and long-term results of maxillary distraction osteogenesis compared to orthognathic surgery for the treatment of hypoplastic maxilla in people with cleft lip and palate. SEARCH METHODS: Cochrane Oral Health's Information Specialist searched the following databases: Cochrane Oral Health's Trials Register (to 15 May 2018), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2018, Issue 4), MEDLINE Ovid (1946 to 15 May 2018), Embase Ovid (1980 to 15 May 2018), and LILACS BIREME Virtual Health Library (Latin American and Caribbean Health Science Information database; from 1982 to 15 May 2018). The US National Institutes of Health Trials Registry (ClinicalTrials.gov) and the World Health Organization International Clinical Trials Registry Platform were searched for ongoing trials. No restrictions were placed on the language or date of publication when searching the electronic databases. SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing maxillary distraction osteogenesis to conventional Le Fort I osteotomy for the correction of cleft lip and palate maxillary hypoplasia in non-syndromic cleft patients aged 15 years or older. DATA COLLECTION AND ANALYSIS: Two review authors assessed studies for eligibility. Two review authors independently extracted data and assessed the risk of bias in the included studies. We contacted trial authors for clarification or missing information whenever possible. All standard methodological procedures expected by Cochrane were used. MAIN RESULTS: We found six publications involving a total of 47 participants requiring maxillary advancement of 4 mm to 10 mm. All of them related to a single trial performed between 2002 and 2008 at the University of Hong Kong, but not all of the publications reported outcomes from all 47 participants. The study compared maxillary distraction osteogenesis with orthognathic surgery, and included participants from 13 to 45 years of age.Results and conclusions should be interpreted with caution given the fact that this was a single trial at high risk of bias, with a small sample size.The main outcomes assessed were hard and soft tissue changes, skeletal relapse, effects on speech and velopharyngeal function, psychological status, and clinical morbidities.Both interventions produced notable hard and soft tissue improvements. Nevertheless, the distraction group demonstrated a greater maxillary advancement, evaluated as the advancement of Subspinale A-point: a mean difference of 4.40 mm (95% CI 0.24 to 8.56) was recorded two years postoperatively.Horizontal relapse of the maxilla was significantly less in the distraction osteogenesis group five years after surgery. A total forward movement of A-point of 2.27 mm was noted for the distraction group, whereas a backward movement of 2.53 mm was recorded for the osteotomy group (mean difference 4.8 mm, 95% CI 0.41 to 9.19).No statistically significant differences could be detected between the groups in speech outcomes, when evaluated through resonance (hypernasality) at 17 months postoperatively (RR 0.11, 95% CI 0.01 to 1.85) and nasal emissions at 17 months postoperatively (RR 3.00, 95% CI 0.14 to 66.53), or in velopharyngeal function at the same time point (RR 1.28, 95% CI 0.65 to 2.52).Maxillary distraction initially lowered social self-esteem at least until the distractors were removed, at three months postoperatively, compared to the osteotomy group, but this improved over time and the distraction group had higher satisfaction with life in the long term (two years after surgery) (MD 2.95, 95% CI 014 to 5.76).Adverse effects, in terms of clinical morbidities, included mainly occlusal relapse and mucosal infection, with the frequency being similar between groups (3/15 participants in the distraction osteogenesis group and 3/14 participants in the osteotomy group). There was no severe harm to any participant. AUTHORS' CONCLUSIONS: This review found only one small randomised controlled trial concerning the effectiveness of distraction osteogenesis compared to conventional orthognathic surgery. The available evidence is of very low quality, which indicates that further research is likely to change the estimate of the effect. Based on measured outcomes, distraction osteogenesis may produce more satisfactory results; however, further prospective research comprising assessment of a larger sample size with participants with different facial characteristics is required to confirm possible true differences between interventions.

Effect of orthodontic treatment with 4 premolar extractions compared with nonextraction treatment on the vertical dimension of the face: A systematic review.

INTRODUCTION: Our aim was to assess the available evidence for the effects of orthodontic treatment with 4 premolar extractions on the skeletal vertical dimension of the face compared with nonextraction treatment. METHODS: Electronic database searches (MEDLINE, EMBASE, Cochrane Oral Health Group's Trials Register, and CENTRAL) of published and unpublished literature and hand searches of eligible studies were performed, with no language or publication date restrictions. Two authors performed data extraction independently and in duplicate. Risk of bias was assessed. RESULTS: After application of the eligibility criteria, 14 studies were included in this systematic review. All were retrospective. Risk of bias ranged from moderate to critical. Ten studies investigated patients with various skeletal vertical patterns and classes of malocclusion and found no difference between extraction (Ex) and nonextraction (Nonex) treatment in regard to the vertical dimension. Only 2 studies found statistically significant increases in the nonextraction groups, one in N-Me (Ex: +1.5 mm; Nonex: +5.5 mm; P <0.05) and one in SN-GoGn (Ex: -0.9°; Nonex: +0.8°; P <0.05), but without a concurrent significant change in other vertical measurements such as FMA. Two other studies showed opposite findings regarding N-Me (Ex: +2.3 mm; Nonex: +0.9 mm; P <0.05) and FMA (Ex: +0.3°; Nonex: -2.0°; P <0.05). CONCLUSIONS: Although the quality of evidence ranged from moderate to low, there was considerable agreement among these studies, suggesting that orthodontic treatment with 4 premolar extractions has no specific effect on the skeletal vertical dimension. Thus, an extraction treatment protocol aiming to reduce or control the vertical dimension does not seem to be an evidence-based clinical approach.

Performance of clear vacuum-formed thermoplastic retainers depending on retention protocol: a systematic review.

We aimed at comparing the performance of vacuum-formed thermoplastic retainers (VFR) worn either full-time or part-time, in maintaining orthodontic treatment results in terms of tooth alignment, arch form and occlusion. We reviewed randomized and prospective controlled clinical trials comparing VFR wearing protocols and searched databases, without restrictions, for published and unpublished literature. The risk of bias was assessed using the Cochrane Risk of Bias tool and the overall level of certainty in the evidence following ADA methodology. 184 studies were initially identified and reduced to the 3 randomized controlled trials included in the systematic review by means of specific criteria. One study followed patients 1 year into retention, and the other two for 6 months. Little's Irregularity Index, intermolar and intercanine width, arch length, overjet and PAR score did not differ significantly between the patients wearing their retainers part time or full time. We observed a slight increase in the overbite in the part-time group in only one trial. With a moderate level of certainty, we found that during the observation period, full-time VFR wear is not superior to part-time, bearing in mind the potential implications for health burden, retainer longevity and cost-effectiveness, as well as patient satisfaction and compliance.

Condylar resorption in orthognathic patients after mandibular bilateral sagittal split osteotomy: a systematic review.

Objective: To systematically search the literature and assess the available evidence regarding the incidence and quantification of condylar resorption following bilateral sagittal split osteotomy (BSSO) of the mandible in orthognathic patients. Search methods: Electronic database searches of published and unpublished literature were performed. The reference lists of eligible studies were hand searched for additional studies. Selection criteria: Randomized clinical trials (RCTs), prospective, and retrospective studies with patients of any age that underwent BSSO were included. Data collection and analysis: Study selection, data extraction, and risk of bias assessment were performed individually and in duplicate. Results: One RCT, 3 prospective, and 10 retrospective studies were included in this review. The lack of standardized protocols and the high amount of heterogeneity precluded a valid interpretation of the actual results through pooled estimates. There was a substantial consistency among studies, however, that young, female patients with mandibular deficiency and high mandibular plane angle, submitted to surgical counterclockwise rotation of mandibular segments, were more prone to a higher risk for condylar resorption after BSSO. The level of evidence was found to be low given the high/serious risk of bias in all included studies. Conclusions: Condylar resorption should be taken into account as a potential postsurgical complication after BSSO. However, its incidence and quantification need precautious interpretation owing to the low level of evidence and the high heterogeneity of studies. Additional high-quality prospective research assisted by 3D imaging technology is needed to allow more definitive conclusions. Registration: Study not registered. Conflict of interest: None.

Maxillary distraction osteogenesis versus orthognathic surgery for cleft lip and palate patients.

BACKGROUND: Cleft lip and palate is one of the most common birth defects and can cause difficulties with feeding, speech and hearing, as well as psychosocial problems. Treatment of orofacial clefts is prolonged; it typically commences after birth and lasts until the child reaches adulthood or even into adulthood. Residual deformities, functional disturbances, or both, are frequently seen in adults with a repaired cleft. Conventional orthognathic surgery, such as Le Fort I osteotomy, is often performed for the correction of maxillary hypoplasia. An alternative intervention is distraction osteogenesis, which achieves bone lengthening by gradual mechanical distraction. OBJECTIVES: To provide evidence regarding the effects and long-term results of maxillary distraction osteogenesis compared to orthognathic surgery for the treatment of hypoplastic maxilla in people with cleft lip and palate. SEARCH METHODS: We searched the following electronic databases: Cochrane Oral Health's Trials Register (to 16 February 2016), the Cochrane Central Register of Controlled Trials (CENTRAL) (the Cochrane Library, 2016, Issue 1), MEDLINE Ovid (1946 to 16 February 2016), Embase Ovid (1980 to 16 February 2016), LILACS BIREME (1982 to 16 February 2016), the US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) (to 16 February 2016), and the World Health Organization (WHO) International Clinical Trials Registry Platform (to 16 February 2016). There were no restrictions regarding language or date of publication in the electronic searches. We performed handsearching of six speciality journals and we checked the reference lists of all trials identified for further studies. SELECTION CRITERIA: We included randomised controlled trials (RCTs) comparing maxillary distraction osteogenesis to conventional Le Fort I osteotomy for the correction of cleft lip and palate maxillary hypoplasia in non-syndromic cleft patients aged 15 years or older. DATA COLLECTION AND ANALYSIS: Two review authors assessed studies for eligibility. Two review authors independently extracted data and assessed the risk of bias in the included studies. We contacted trial authors for clarification or missing information whenever possible. All standard methodological procedures expected by Cochrane were used. MAIN RESULTS: We found six publications involving a total of 47 participants requiring maxillary advancement of 4 mm to 10 mm. All of them related to a single trial performed between 2002 and 2008 at the University of Hong Kong, but not all of the publications reported outcomes from all 47 participants. The study compared maxillary distraction osteogenesis with orthognathic surgery, and included participants from 13 to 45 years of age.Results and conclusions should be interpreted with caution given the fact that this was a single trial at high risk of bias, with a small sample size.The main outcomes assessed were hard and soft tissue changes, skeletal relapse, effects on speech and velopharyngeal function, psychological status, and clinical morbidities.Both interventions produced notable hard and soft tissue improvements. Nevertheless, the distraction group demonstrated a greater maxillary advancement, evaluated as the advancement of Subspinale A-point: a mean difference of 4.40 mm (95% CI 0.24 to 8.56) was recorded two years postoperatively.Horizontal relapse of the maxilla was significantly less in the distraction osteogenesis group five years after surgery. A total forward movement of A-point of 2.27 mm was noted for the distraction group, whereas a backward movement of 2.53 mm was recorded for the osteotomy group (mean difference 4.8 mm, 95% CI 0.41 to 9.19).No statistically significant differences could be detected between the groups in speech outcomes, when evaluated through resonance (hypernasality) at 17 months postoperatively (RR 0.11, 95% CI 0.01 to 1.85) and nasal emissions at 17 months postoperatively (RR 3.00, 95% CI 0.14 to 66.53), or in velopharyngeal function at the same time point (RR 1.28, 95% CI 0.65 to 2.52).Maxillary distraction initially lowered social self-esteem at least until the distractors were removed, at three months postoperatively, compared to the osteotomy group, but this improved over time and the distraction group had higher satisfaction with life in the long term (two years after surgery) (MD 2.95, 95% CI 014 to 5.76).Adverse effects, in terms of clinical morbidities, included mainly occlusal relapse and mucosal infection, with the frequency being similar between groups (3/15 participants in the distraction osteogenesis group and 3/14 participants in the osteotomy group). There was no severe harm to any participant. AUTHORS' CONCLUSIONS: This review found only one small randomised controlled trial concerning the effectiveness of distraction osteogenesis compared to conventional orthognathic surgery. The available evidence is of very low quality, which indicates that further research is likely to change the estimate of the effect. Based on measured outcomes, distraction osteogenesis may produce more satisfactory results; however, further prospective research comprising assessment of a larger sample size with participants with different facial characteristics is required to confirm possible true differences between interventions.