Periodontal outcomes associated with impacted maxillary central incisor and canine teeth following surgical exposure and orthodontic alignment: a systematic review and meta-analysis.

BACKGROUND: Maxillary incisor and canine teeth are commonly impacted and require multidisciplinary treatment to accommodate them in the dental arch. OBJECTIVES: To assess the periodontal outcomes of impacted maxillary central incisor and canine teeth, which have been successfully aligned in the arch following surgical exposure and orthodontic traction with fixed appliance therapy. SEARCH METHODS: Systematic literature searches without restrictions were undertaken in eight databases. SELECTION CRITERIA: Studies reporting surgical interventions in combination with orthodontic traction with fixed appliance therapy to align impacted maxillary incisors or canines published up to January 2023. DATA COLLECTION: Duplicate independent study selection, data extraction, and risk of bias assessment. ANALYSIS: Random-effects meta-analyses of aggregate data. RESULTS: Twenty-three studies (21 retrospective and 2 prospective) were included in the final analysis. Three studies reported outcomes for maxillary central incisors and 20 reported outcomes for maxillary canines. For maxillary central incisors, all three studies were rated as being at moderate risk of bias. For maxillary canines, 17 studies and 1 study were rated at moderate and high risk of bias, respectively. Both prospective studies were rated at a low risk of bias. Meta-analyses comparing aligned impacted maxillary canines to their non-impacted contralateral counterparts found the former had increased Plaque Index scores (mean difference [MD] 0.19; 95% confidence interval [CI] 0.03, 0.35; P = 0.03), increased clinical attachment loss (MD 0.40 mm; 95% CI 0.17, 0.63; P = 0.01), increased pocket probing depth (MD 0.18 mm; 95% CI 0.07, 0.28; P = 0.001), increased bone loss (MD 0.51 mm; 95% CI 0.31, 0.72; P < 0.001), and reduced keratinized gingival width (MD -0.31 mm; 95% CI -0.61, -0.01; P = 0.04). CONCLUSIONS: Limited evidence suggests that surgical exposure and orthodontic alignment of impacted maxillary central incisor or canine teeth, results in modest adverse effects in the periodontium. These findings should be viewed with caution as our certainty for these outcomes is very low to low due to the bias and heterogeneity. Further well-conducted studies reporting patient centred outcomes are required. REGISTRATION: PROSPERO (CRD42020225639).

Interventions to facilitate the successful eruption of impacted maxillary incisor teeth due to the presence of a supernumerary: A systematic review and meta-analysis.

INTRODUCTION: A failure of maxillary incisor eruption is commonly attributed to the presence of a supernumerary tooth. This systematic review aimed to assess the percentage of impacted maxillary incisors that successfully erupt after surgical removal of supernumerary teeth with or without other interventions. METHODS: Systematic literature searches without restrictions were undertaken in 8 databases for studies reporting any intervention aimed at facilitating incisor eruption, including surgical removal of the supernumerary alone or in conjunction with additional interventions published up to September 2022. After duplicate study selection, data extraction, and risk of bias assessment according to the risk of bias in nonrandomized studies of interventions and Newcastle-Ottawa scale, random-effects meta-analyses of aggregate data were conducted. RESULTS: Fifteen studies (14 retrospective and 1 prospective) were included with 1058 participants (68.9% male; mean age, 9.1 years). The pooled eruption prevalence for removal of the supernumerary tooth with space creation or removal of the supernumerary tooth with orthodontic traction was significantly higher at 82.4% (95% confidence interval [CI], 65.5-93.2) and 96.9% (95% CI, 83.8-99.9) respectively, compared with removal of an associated supernumerary only (57.6%; 95% CI, 47.8-67.0). The odds of successful eruption of an impacted maxillary incisor after removal of a supernumerary were more favorable if the obstruction was removed in the deciduous dentition (odds ratio [OR], 0.42; 95% CI, 0.20-0.90; P = 0.02); if the supernumeraries were conical (OR, 2.91; 95% CI, 1.98-4.28; P <0.001); if the incisor was in the correct position (OR, 2.19; 95% CI, 1.14-4.20; P = 0.02), at the level of the gingival third (OR 0.07; 95% CI, <0.01-0.97; P = 0.04) and had incomplete root formation (OR, 9.02; 95% CI, 2.04-39.78; P = 0.004). Delaying removal of the supernumerary tooth 12 months after the expected eruption time of the maxillary incisor (OR, 0.33; 95% CI, 0.10-1.03; P = 0.05) and waiting >6 months for spontaneous eruption after removal of the obstacle (OR, 0.13; 95% CI, 0.03-0.50; P = 0.003) was associated with worse odds for eruption. CONCLUSIONS: Limited evidence indicated that the adjunctive use of orthodontic measures and removal of supernumerary teeth might be associated with greater odds of successfull impacted incisor eruption than removal of the supernumerary tooth alone. Certain characteristics related to supernumerary type and the position or developmental stage of the incisor may also influence successful eruption after removal of the supernumerary. However, these findings should be viewed with caution as our certainty is very low to low because of bias and heterogeneity. Further well-conducted and reported studies are required. The results of this systematic review have been used to inform and justify the iMAC Trial.

Salivary peptidome analysis and protease prediction during orthodontic treatment with fixed appliances.

Orthodontic tooth movement (OTM) occurs through proteolytic remodelling within the periodontium following the application of external force to the tooth. This study describes the first characterization of the salivary peptidome and protease profile during the alignment stage of fixed appliance orthodontic treatment. Unstimulated whole mouth saliva from 16 orthodontic patients (10 males, 6 females, mean (SD) age 15.2 (1.6) years) was collected prior to fixed appliance placement (T1), 1-h (T2), 1-week (T3) following fixed appliance placement and on completion of mandibular arch alignment (T4). Salivary peptides were extracted using filtration followed by mass spectrometry to identify amino acid sequences. Protease prediction was carried out in silico using Proteasix and validated with gelatin zymography and enzyme-linked immunosorbent assay. A total of 2852 naturally-occurring peptides were detected, originating from 436 different proteins. Both collagen and statherin-derived peptide levels were increased at T2. Proteasix predicted 73 proteases potentially involved in generating these peptides, including metalloproteinases, calpains and cathepsins. Changes in predicted activity of proteases over time were also observed, with most metalloproteinases showing increased predicted activity at T2-T3. Increased gelatinolytic activity and MMP8/MMP9 levels were detected at T3. Collectively, multiple protein targets and changes in protease-predicted activity during OTM have been identified.

Duration of canine retraction with fixed appliances: A systematic review and meta-analysis.

INTRODUCTION: Space closure is a challenging and time-consuming phase of orthodontic treatment with fixed appliances. This systematic review evaluated canine retraction duration using fixed appliances after maxillary first premolar extraction. METHODS: Unrestricted systematic literature searches were conducted in 8 databases for randomized clinical trials, assessing the duration and rate of maxillary canine retraction using fixed appliances with or without treatment adjuncts published up to July 2021. Study selection, data extraction, and risk of bias evaluation were conducted independently and in duplicate. Random-effects meta-analyses of average rates or mean differences (MD) and 95% confidence intervals (CI) were conducted at α = 5%, followed by sensitivity and Grading of Recommendations Assessment, Development, and Evaluation analysis. RESULTS: Fifty randomized clinical trials (6 parallel and 44 split-mouth designs) covering 811 participants (mean age 19.9 years; 34% male) were included. The estimated average pooled duration to achieve complete canine retraction was 4.98 months (2 trials; 95% CI, -2.9 to 12.88 months). Pooled average canine retraction was 0.97 mm at months 0-1 (23 trials; 95% CI, 0.79-1.16), 1.83 mm at months 0-2 (20 trials; 95% CI, 1.52-2.14), 2.44 mm at months 0-3 (23 trials; 95% CI, 2.10-2.79), 3.49 mm at months 0-4 (6 trials; 95% CI, 1.81-5.17) and 4.25 mm at months 0-5 (2 trials; 95% CI, 0.36-8.14). Surgically-assisted orthodontics was associated with greater canine retraction at all time points: months 0-1 (10 trials; MD, 0.52 mm; P = 0.004), months 0-2 (8 trials; MD, 0.53 mm; P = 0.04), months 0-3 (8 trials; MD, 0.67 mm; P = 0.01), and months 0-4 (3 trials; MD, 1.13 mm; P = 0.01), whereas subgroup analyses indicated significant effects of anchorage reinforcement method and bracket slot size on canine retraction. CONCLUSIONS: The average time to achieve complete retraction of the maxillary canine using fixed appliances was around 5.0 months. Most studies used split-mouth randomization to investigate canine retraction for around 1-3 months, with substantial heterogeneity across studies. At 3 months of treatment, high-quality evidence supported greater canine retraction with surgically-assisted orthodontics.

Duration of tooth alignment with fixed appliances: A systematic review and meta-analysis.

INTRODUCTION: A key goal of orthodontic treatment with fixed appliances is alignment of the dentition, and this remains a commonly selected outcome in clinical studies investigating orthodontic tooth movement. This systematic review has evaluated treatment duration to achieve alignment of the mandibular dentition using fixed appliances. METHODS: Systematic literature searches without restrictions were undertaken in 9 databases for randomized clinical trials (RCTs) assessing duration and rate of tooth alignment using fixed appliances with or without treatment adjuncts published up to January 2021. After duplicate study selection, data extraction, and risk of bias assessment according to Cochrane, random-effects meta-analyses of aggregate data, and individual patient data were conducted. RESULTS: Thirty-five trials were included with 2258 participants (39% male; mean age 17.8 years), giving a pooled duration to achieve whole-arch alignment of the mandibular dentition of 263.0 days (4 trials; 95% confidence interval [CI], 186.7-339.4 days) and incisor alignment in the mandibular arch of 100.7 days (9 trials; 95% CI, 84.1-117.4 days). Surgical-assisted orthodontics was associated with reduced duration of incisor alignment: mean difference of 44.3 days less (4 trials; 95% CI, 20.0-68.9 days; P <0.001; high quality of evidence), whereas subgroup and meta-regression analyses indicated significant effects of baseline crowding and premolar extractions. Individual patient data analysis from 3 RCTs indicated that for each additional participant age year, whole-arch alignment of the mandibular dentition took 13.7 days longer (3 trials; 95% CI, 7.7-17.7 days; P <0.001) and for each additional mm of irregularity, 17.5 days more were needed (2 trials; 95% CI, 9.8-25.2 days; P <0.001). CONCLUSIONS: Patient and treatment-related characteristics can significantly affect the duration of tooth alignment and should be taken into account both clinically and when designing trial outcomes. Future research studies investigating rates of orthodontic tooth alignment would benefit from adequate sample sizes and a more consistent methodology in outcome assessment. Data in this systematic review provides a basis for appropriate trial design for future RCTs investigating the rate of orthodontic tooth alignment with fixed appliances.