Effect of rapid maxillary expansion and transpalatal arch treatment associated with deciduous canine extraction on the eruption of palatally displaced canines: A 2-center prospective study

Short-Term Impact of Slow Maxillary Expansion on Labial Ectopic Canine Eruption Pathway in Children: A Retrospective Study

Objectives: This retrospective study evaluated the short-term effects of removable slow maxillary expansion (SME) on eruption patterns of labially ectopic canines in a Chinese pediatric population, comparing treated patients with untreated controls. Methods: Seventy-six patients (mean age 8.38 ± 0.88 years) underwent SME treatment for 11.04 ± 4.44 months. Canine positions were categorized as labial ectopic (TE: n = 40) or normally positioned (TN: n = 112). The TE group was stratified vertically: superior (TES; n = 15, canines above lateral incisors' roots or adjacent to unerupted incisors) and inferior (TEI; n = 25, canines adjacent to erupted lateral incisors' roots). Untreated controls (n = 58; mean age 8.46 ± 0.78 years) included labial ectopic (CE group; n = 32) and normal canines (CN group; n = 84), with CE further divided vertically into CES (n = 24) and CEI (n = 8). Panoramic radiographs at baseline (T0) and follow-up (T1) evaluated sector distribution, midline proximity (3c-ML: canine cusp to midline distance), vertical position (3c-OP: cusp to occlusal plane distance), and angular (3^ML: canine-midline angle). Results: SME significantly improved midline proximity (3c-ML increased) while reducing vertical height (3c-OP decreased) and angulation (3^ML reduced) in the TE group. Notably, TE patients revealed a significantly greater increase in 3c-ML compared to CE. Subgroup analysis showed that TEI canines exhibited significant improvements in all three parameters (3c-OP, 3c-ML, and 3^ML), whereas TES canines displayed minimal changes. The shifts in sector distribution were similar between the treatment and control groups. Conclusions: SME demonstrated short-term efficacy in guiding labially ectopic canines toward more favorable eruption trajectories, particularly when erupted beyond the roots of the lateral incisor. The observed positional improvements underscore SME's potential to optimize eruption outcomes during early orthodontic intervention.

Aligners as a Therapeutic Approach in Impacted Canine Treatment: A Systematic Review

Background/Objectives: The growing demand for esthetic, less painful, and more comfortable orthodontic treatment has led to increasing use of aligner systems. Initially used for less complicated malocclusions, aligners are now being incorporated into complex treatment plans, including cases involving impacted teeth. While aligners are a popular alternative to traditional fixed appliances, they still have limitations. This study aims to evaluate the effectiveness of aligner-based orthodontic treatment in patients with impacted or significantly ectopic canines. Methods: This study was conducted in accordance with the PRISMA guidelines. The search terms used were as follows: 'Clear Aligner' OR 'Invisalign' AND 'Impacted Canine' OR 'Impacted Tooth' OR 'Ectopic Tooth' OR 'Ectopic Canine.' A total of 1101 records were identified, of which 170 articles underwent screening. Fifteen articles were assessed for eligibility, and ultimately six case reports and one three-dimensional finite element analysis (FEA) study were included for both quantitative and qualitative synthesis. Results: According to the studies, additional appliances are often required to achieve favorable outcomes when treating impacted canines with aligner systems. Temporary anchorage devices (TADs) were used in 5 out of 9 reported cases for canine traction into the dental arch. In three cases, TADs were combined with sectional wires implemented as cantilevers. Elastics were used in 6 out of 9 cases for traction to the opposite arch, and in 5 out of 9 cases as interarch elastics attached to the aligners. Interarch elastics were applied in various ways, either directly to the aligners or to primary canines using hidden buttons inside pontics or dovetail hooks. Elastics were also anchored to the lower arch with class II, class III, or cross-arch (criss-cross) mechanics. Conclusions: This review highlights the promising potential of aligner systems in the treatment of impacted canines. However, additional auxiliaries, such as TADs, sectional wires, or elastics remain nearly essential for initial canine traction. Aligner systems offer versatile treatment options, and the possibility of reduced treatment time represents a valuable area for future research.

Effectiveness of Dental Restorative Materials in the Atraumatic Treatment of Carious Primary Teeth in Pediatric Dentistry: A Systematic Review

AIM

This systematic review evaluates the effectiveness and clinical outcomes of Atraumatic Restorative Treatment (ART) in pediatric dentistry, comparing it with other restorative techniques, analyzing material performance, assessing cost-effectiveness, and exploring the long-term success in managing dental caries.

BACKGROUND

ART is a minimally invasive approach that removes decayed tissue using hand instruments and restores teeth with adhesive materials like glass ionomer cement (GIC). ART is particularly valuable in pediatric dentistry due to its simplicity, reduced discomfort, and suitability for resource-limited settings. It eliminates the need for anesthesia and expensive dental equipment, making it accessible in remote and underserved areas. Studies have shown its effectiveness in providing durable restorations while improving patient comfort.

MATERIALS AND METHODS

This systematic review follows the PRISMA guidelines. PubMed, Web of Science, and Scopus were searched for studies published in the last ten years. The inclusion criteria included in vivo studies on children, randomized controlled trials, and case-control studies assessing ART's effectiveness. Quality and risk of bias were evaluated using the ROBINS-I tool.

RESULTS

Eighteen studies met the inclusion criteria. ART effectively managed dental caries, especially with high-viscosity GIC. Comparisons with the Hall Technique and Papacarie showed that ART remains a viable, cost-effective option.

CONCLUSIONS

ART is a reliable, minimally invasive technique for pediatric restorative dentistry. Its accessibility and cost-effectiveness make it suitable for low-resource settings. High-quality materials and technique modifications further enhance restoration longevity.

Evaluating the success rates and effectiveness of surgical and orthodontic interventions for impacted canines: a systematic review of surgical and orthodontic interventions and a case series

OBJECTIVES

The goal is to gather more information on orthodontic traction of impacted canines in the arch or their extraction.

METHODS

We focused our search on English-language papers published between January 1, 2004, and July 24, 2024 in PubMed, Scopus, and Web of Science that were relevant to our topic. The search strategy employed the Boolean terms "impacted" AND "canine". In addition to the overview, this article discusses a number of clinical instances involving canine disinclusion.

RESULTS

The study analyzed 2748 papers from databases like Web of Science, PubMed, and Scopus, resulting in 1455 articles after eliminating duplicates. After examining titles and abstracts, 897 entries were removed. The remaining 558 papers were confirmed, with 543 items removed due to being off-topic. The study includes a qualitative analysis of the 15 final articles.

CONCLUSIONS

This article concludes that both extraction and orthodontic traction are effective treatments for impacted canines, with the choice depending on patient-specific factors. Advances in surgical techniques and imaging technologies have improved outcomes, while a multidisciplinary, patient-centered approach remains essential. Future research should focus on refining treatment selection criteria and integrating genetic and technological advancements.

The sacrosanct canine: Considerations for the extraction of severely displaced, or impacted maxillary canine(s)

OBJECTIVE

The maxillary canines have long been considered critical for dental function and aesthetics, with traditional practice prioritizing their preservation and alignment. However, this view often stems from outdated teachings rather than evidence-based principles, since there is no scientific support for the concept of canine-protected occlusion. Therefore, this commentary paper provides justification for extraction of severely impacted maxillary canines with first premolar substitution.

RESULTS

In cases of severely impacted maxillary canines, orthodontic alignment may be associated with higher morbidity, unpredictable outcomes, prolonged treatment times, and increased patient burden. As an alternative, extracting the impacted canines and substituting the first premolars offers a viable, efficient solution that can achieve functional and aesthetic outcomes with fewer complications.

CONCLUSION

This paper challenges traditional perspectives on the management of impacted canines, advocating for an evidence-based approach that prioritizes patient-centered care.

The Diagnosis and Management of Infraoccluded Deciduous Molars: A Systematic Review

The infraocclusion (IO) of primary molars, often seen in retained deciduous teeth, is a common condition that presents significant challenges for pediatric oral health. It occurs when primary molars are positioned below the occlusal plane due to the absence of permanent successors, leading to complications such as misaligned teeth, impaired chewing, and long-term dental health issues.

OBJECTIVES

This study examines IO prevalence, diagnosis, and treatment approaches.

METHODS

A systematic review following PRISMA guidelines was conducted, searching PubMed, Web of Science, and Scopus for articles from the last 15 years. Nine articles were included for qualitative analysis.

RESULTS

IO was associated with several complications, including root resorption, altered eruption of adjacent teeth, and space loss within the dental arch. Clinical and radiographic evaluations are key to early detection. Severe cases often require invasive treatments, such as tooth extraction and space maintenance, while mild cases could be monitored.

CONCLUSIONS

IO is prevalent in pediatric dentistry and can lead to significant dental issues if untreated. Early detection and intervention are crucial for preventing complications like tooth misalignment and impacted premolars. Tailored treatment strategies based on severity, along with increased awareness among dental practitioners, are essential to improve long-term outcomes for affected children.

Orthodontic diagnosis rates based on panoramic radiographs in children aged 6-8 years: A retrospective study

Objective

This study aimed to retrospectively analyze the prevalence of orthodontic problems and the proportion of patients who underwent orthodontic diagnosis among children aged 6 (n = 300), 7 (n = 400), and 8 (n = 400) years who had undergone panoramic radiography.

Methods

Children were divided into five groups according to their chief complaint and consultation: conservative dentistry, oral and maxillofacial surgery, orthodontics, periodontics, and prosthodontics). Chief complaints investigated included first molar eruption, lack of space for incisor eruption, frequency of eruption problems, lack of space, impaction, supernumerary teeth (SNT), missing teeth, and ectropion eruption. The number of patients whose chief complaint was not related to orthodontics but had dental problems requiring orthodontic treatment was counted. The proportion of patients with orthodontic problems who received an orthodontic diagnosis was also examined.

Results

Dental trauma and SNT were the most frequent chief complaints among the children. The proportion of patients with orthodontic problems increased with age. However, the orthodontic diagnosis rates based on panoramic radiographs among children aged 6, 7, 8 years were only 1.5% (6 years) and 23% (7 and 8 years).

Conclusions

Accurate information should be provided to patient caregivers to correct misconceptions regarding the appropriateness of delaying orthodontic examination until permanent dentition is established.

Expert consensus on pediatric orthodontic therapies of malocclusions in children

Malocclusion, identified by the World Health Organization (WHO) as one of three major oral diseases, profoundly impacts the dental-maxillofacial functions, facial esthetics, and long-term development of ~260 million children in China. Beyond its physical manifestations, malocclusion also significantly influences the psycho-social well-being of these children. Timely intervention in malocclusion can foster an environment conducive to dental-maxillofacial development and substantially decrease the incidence of malocclusion or reduce the severity and complexity of malocclusion in the permanent dentition, by mitigating the negative impact of abnormal environmental influences on the growth. Early orthodontic treatment encompasses accurate identification and treatment of dental and maxillofacial morphological and functional abnormalities during various stages of dental-maxillofacial development, ranging from fetal stages to the early permanent dentition phase. From an economic and societal standpoint, the urgency for effective early orthodontic treatments for malocclusions in childhood cannot be overstated, underlining its profound practical and social importance. This consensus paper discusses the characteristics and the detrimental effects of malocclusion in children, emphasizing critical need for early treatment. It elaborates on corresponding core principles and fundamental approaches in early orthodontics, proposing comprehensive guidance for preventive and interceptive orthodontic treatment, serving as a reference for clinicians engaged in early orthodontic treatment.

Association between maxillary canine impaction and other dental anomalies: radiological study of a mixed dentition children's cohort from an orthodontic clinic

PURPOSE

To investigate the significance of association between maxillary impacted canines and various dental anomalies.

METHODS

Files of 874 orthodontic patients were evaluated for the presence of maxillary impacted canines. From this sample, a group of 97 patients (39 males and 58 females) with at least 1 impacted maxillary canine consisted the study group. This group was compared to a control group of 97 patients (42 males and 55 females) that was created by random selection from the initial sample without maxillary canine impaction. The impaction diagnosis was made from the panoramic radiographs. Chi-square test was used to perform the analysis for significant associations. Stepwise discriminant analysis, binary logistic regression and classification tree were used to identify best combinations.

RESULTS

Statistically significant difference was found for peg-shaped maxillary lateral incisors and infraoccluded deciduous molars. The presence of peg-shaped upper lateral incisors arises the probability of impacted canine to 83.3%, a distal displaced unerupted second premolar to 63.16% and the impaction of any other teeth to 80% as showed by the classification tree.

CONCLUSIONS

The presence of peg-shaped maxillary lateral incisors and infraocclusion of deciduous molars can be considered major valuable early risk indicators for maxillary canine impaction, because they manifest before the maxillary canine eruption. Special consideration should be given on distal displaced unerupted second premolar and the impaction of any other teeth. Patients with these dental anomalies are candidates for future interceptive treatment for canine eruption.

Estimating the 3-D location of impacted maxillary canines: A CBCT-based analysis of severity of impaction

OBJECTIVES

The objective of the study was to quantify the 3-D location of impacted canines by measuring their linear and angular deviations in relation to adjacent structures and further evaluate impaction severity.

METHODS

CBCT images of 314 impacted canines were analysed in the sagittal, coronal and axial planes. Linear and angular measurements were recorded. Canine inclination was identified in coronal and sagittal planes. An evaluation system was constructed for analysis. Upright canine was considered as the appropriate position for fully erupted maxillary canine. Outcomes were compared between right and left sides and by gender. For categorical variables, chi-square tests were used while Mann-Whitney U test was used for continuous variables. Regression models were used to measure severity.

RESULTS

Impactions were greater in females (119/207; 57.5%). No significant differences between unilateral (100/207; 49.3%) and bilateral (107/207; 51.7%) (P > 0.05). Out of 314 impactions, 105 (33.4%) were mild, 118 (37.58%) moderate and 91 (28.98%) severe. Severe impactions were primarily buccal (44/ 91; 48.3%), in the occlusal ½ of the adjacent incisor root (38/ 91, 41.7%), mesial to the distal border of central incisor (47/91, 51.6%), with sagittal angle value + >45 ̊ (46/ 91, 50.5%) and mesial tip + >30 ̊ (86/ 91, 94.5%).

CONCLUSIONS

Severely impacted canines had their crowns buccal, closer to occlusal plane and mesial to the distal border of the central incisor with greater than 45-degree buccal inclination and greater than 30-degree mesial tip. The sagittal angle can have a significant impact on the severity of impaction. A new classification system was proposed to quantify severity.

Common dental anomalies in Korean orthodontic patients: An update

Objective

The aim of this study was 1) to investigate the prevalence and pattern of dental anomalies (DAs), 2) to compare DAs according to the type of malocclusion, and 3) to investigate the correlation between tooth impaction and other DAs in the Korean orthodontic population.

Methods

A total of 3,240 orthodontic patients were classified as Class I, Class II, or Class III malocclusion groups. The presence and location of common DAs, including impaction, microdontia, agenesis, supernumerary tooth, transposition, and fusion, were identified by examining diagnostic records. Furthermore, samples were classified as Group 1 without impaction or Group 2 with impaction. The prevalence of other DAs concurrent with impaction was investigated and compared to Group 1.

Results

Impaction was the most prevalent DA, followed by microdontia, agenesis, and supernumerary. Class I and Class III groups showed the same order of prevalence, but agenesis was more frequent than microdontia in the Class II group. The prevalence of the four DAs was lowest in the Class III group. Overall, 8.6% of patients were classified into Group 2. The incidence of DAs other than impaction and the prevalence of multiple concurrent DAs were significantly higher in Group 2. Impaction showed a significant relationship with supernumerary tooth, transposition, and fusion.

Conclusions

The prevalence and pattern of DAs varied depending on the type of malocclusion. As there was a higher risk of other DAs in patients with impacted teeth, early detection of the impacted tooth and a detailed diagnosis of other possible DAs may be essential.

Eruption disturbances in the mixed dentition: orthodontic considerations for primary dental care

The primary dental care clinician is in a prime position to identify deviations from normal dental development. Disturbances can affect any new erupting tooth. The objective of this narrative review is to describe several situations in which eruption disturbances can arise during the mixed dentition. It will provide an overview of the orthodontic considerations of these disturbances in addition to key summary points on interceptive management, based on the best available evidence.

Interventions for promoting the eruption of palatally displaced permanent canine teeth, without the need for surgical exposure, in children aged 9 to 14 years

BACKGROUND

A permanent upper (maxillary) canine tooth that grows into the roof of the mouth and frequently does not appear (erupt) is called a palatally displaced canine (PDC). The reported prevalence of PDC in the population varies between 1% and 3%. Management of the unerupted PDC can be lengthy, involving surgery to uncover the tooth and prolonged orthodontic (brace) treatment to straighten it; therefore, various procedures have been suggested to encourage a PDC to erupt without the need for surgical intervention.

OBJECTIVES

To assess the efficacy, safety and cost-effectiveness of any interceptive procedure to promote the eruption of a PDC compared to no treatment or other interceptive procedures in young people aged 9 to 14 years old.

SEARCH METHODS

An information specialist searched four bibliographic databases up to 3 February 2021 and used additional search methods to identify published, unpublished and ongoing studies.

SELECTION CRITERIA

We included randomised controlled trials (RCT) involving at least 80% of children aged between 9 and 14 years, who were diagnosed with an upper PDC and undergoing an intervention to enable the successful eruption of the unerupted PDC, which was compared with an untreated control group or another intervention.

DATA COLLECTION AND ANALYSIS

Two review authors, independently and in duplicate, examined titles, keywords, abstracts, full articles, extracted data and assessed risk of bias using the Cochrane Risk of Bias 1 tool (RoB1). The primary outcome was summarised with risk ratios (RR) and 95% confidence intervals (CI). We reported an intention-to-treat (ITT) analysis when data were available and a modified intention-to-treat (mITT) analysis if not. We also undertook several sensitivity analyses. We used summary of findings tables to present the main findings and our assessment of the certainty of the evidence.

MAIN RESULTS

We included four studies, involving 199 randomised participants (164 analysed), 108 girls and 91 boys, 82 of whom were diagnosed with unilateral PDC and 117 with bilateral PDC. The participants were aged between 8 and 13 years at recruitment. The certainty of the evidence was very low and future research may change our conclusions. One study (randomised 67 participants, 89 teeth) found that extracting the primary canine may increase the proportion of PDCs that successfully erupt into the mouth at 12 months compared with no extraction (RR 2.87, 95% CI 0.90 to 9.23; 45 participants, 45 PDCs analysed; very low-certainty evidence), but the CI included the possibility of no difference; therefore the evidence was uncertain. There was no evidence that extraction of the primary canine reduced the number of young people with a PDC referred for surgery at 12 months (RR 0.61 (95% CI 0.29 to 1.28). Three studies (randomised 132 participants, 227 teeth) found no difference in the proportion of successfully erupted PDCs at 18 months with a double primary tooth extraction compared with extraction of a single primary canine (RR 0.68, 95% CI 0.35 to 1.31; 119 participants analysed, 203 PDCs; mITT; very low-certainty evidence). Two of these studies found no difference in the proportions referred for surgical exposure between the single and the double primary extraction groups data at 48 months (RR 0.31, 95% CI 0.06 to 1.45).  There are some descriptive data suggesting that the more severe the displacement of the PDC towards the midline, the lower the proportion of successfully erupted PDCs with or without intervention.

AUTHORS' CONCLUSIONS

The evidence that extraction of the primary canine in a young person aged between 9 and 14 years diagnosed with a PDC may increase the proportion of erupted PDCs, without surgical intervention, is very uncertain. There is no evidence that double extraction of primary teeth increases the proportion of erupted PDC compared with a single primary tooth extraction at 18 months or the proportion referred for surgery by 48 months. Because we have only low to very low certainty in these findings, future research is necessary to help us know for sure the best way to deal with upper permanent teeth that are not erupting as expected.

Effect of sinus proximity, alveolar bone level, and initial buccolingual inclination on behavior of maxillary first molar under expansion force: a finite element analysis

BACKGROUND

The primary aim of this study is to determine whether sinus proximity increases or decreases molar tipping under the force of expansion; a secondary aim is to compare the effect of the initial buccal inclination, alveolar bone loss, and sinus proximity to molar movement under expansion force, by assessing the stress distribution of the periodontal ligament and the changes in the moment/force (M/F) ratio).

METHODS

Twenty different 3-dimensional models were created by changing the buccal inclination (0°,5°,10°,15°, and 20°) value of maxillary molar and simulating different amounts of alveolar bone loss (0, 2,4, and 6 mm) in the basic model. Additionally, an artificial sinus was added to the basic model, and the penetration of the roots into the sinus to different levels (2, 4, and 6 mm) was simulated separately. Thus, 9 additional models were created. The M/F ratio, location of the center of resistance, and principal stresses on the periodontal ligament were analyzed for each of the 29 models separately in a finite element analysis.

RESULTS

The M/F ratio increased as initial buccal inclination or bone loss increased. As the amount of simultaneous penetration of 3 roots into the sinus increased, the M/F ratio decreased. Incremental changes of both the initial inclination value and the amount of bone loss resulted in higher maximum compressive stress on the apices of the buccal roots.

CONCLUSIONS

Increases in alveolar bone loss and buccal inclination caused increases in the periodontal stress. Penetration of the roots into the sinus provides bicortical anchorage and could prevent unwanted crown tipping.

Interventions for impacted maxillary canines: A systematic review of the relationship between initial canine position and treatment outcome

BACKGROUND

The objective of this review was to critically assess the existing literature on the relationship between the initial position of impacted canines and treatment outcomes.

METHODS

We performed a systematic review of the available literature until February 2020 using the MEDLINE, Cochrane Central, Web of Science and PubMed databases. Prospective and retrospective studies (randomized controlled trials [RCTs], cohort studies, longitudinal follow-up studies) considering impacted maxillary canines that were orthodontically and/or surgically treated, and clearly reporting the initial position using 2D and/or 3D classifications, were included if they assessed at least one of the following: treatment success, treatment duration, number of treatment visits, radiographic outcome, periodontal health, esthetics and/or treatment complications. The included studies were assessed for risk of bias according to the Cochrane guidelines.

RESULTS

Seventeen studies were reviewed (2 RCTs and 15 non-RCTs). The included studies enrolled a total of 1247 patients with an average age of 14.1 years and a total of 1597 impacted canines. Various causal relationships were detected between the success of treatment modalities and the initial state of the impacted canine (bucco-palatal position, vertical position, canine angulation, root development).

DISCUSSION

Evidence, though limited, suggests that a higher alpha angle, higher vertical position and more mesial sector of the impacted canine are related to less successful interceptive and active treatment solutions, prolonged treatment time and inferior outcomes.

Prediction of spontaneous eruption of palatally displaced canine based on variables measurements in panoramic radiograph: A systematic review

OBJECTIVE

This systematic review was aimed to find out possible predictive variables measured on panoramic radiographs to predict spontaneous eruption of palatally displaced canine (PDC) after interceptive extraction in late mixed dentition.

MATERIALS AND METHODS

Electronic database searches were performed in MEDLINE, Cochrane's CENTRAL, Scopus, and in other sources up to June 2020. Randomized and nonrandomized controlled trials, and pre-post prospective studies without control groups were considered for review. Study selection, data extraction, risk of bias assessment (by RoB 2.0, ROBINS-I, and NHLBI score), and the certainty of evidence evaluation (GRADE approach) were performed during reviewing process. Only qualitative analyses of included literature were done due to presence of between study heterogeneity.

RESULTS

Out of 970 retrieved records, 3 controlled trials and 3 prospective before and after studies without control fulfilled the eligibility criteria and were included in the review. Studies were assessed at low risk to high risk of bias. Overall certainty was moderate to very low. Results shows that PDCs in distal sectors, lower alpha angle, younger subjects, PDCs with less advanced developed root were significantly benefited from interceptive extraction. However, Vertical distance had insignificant roll on eruption prediction.

CONCLUSIONS

Interceptive extraction at younger age, mesial canine crown position (sectors), and mesial inclination of PDC (alpha angulation) are the most important variables predicting the spontaneous eruption of palatally displaced canine. Findings of this review can be utilized to make evidence-based decisions for managing PDCs with diverse sectors and mesial inclinations. However, well designed clinical trials are recommended to strengthen the evidence.

Surgically assisted orthodontic alignment of impacted maxillary canines: A retrospective analysis of functional and esthetic outcomes and risk factors for failure

INTRODUCTION

The initial position of an impacted maxillary canine might influence the outcome of surgically assisted exposure and orthodontic alignment. Therefore, the purpose of this study was to evaluate existing correlations between the initial position of the maxillary canine and the outcomes of treatment.

METHODS

A retrospective cohort study was designed, containing data of 132 patients (47 males, 106 females; median age at the date of surgical exposure 14 ± 4.6 years; range, 10-39 years) with a total of 153 impacted maxillary canines. The sample was based on orthodontic referrals over 4 years at the Department of Oral and Maxillofacial Surgery, Rijnstate Hospital, Arnhem, the Netherlands. The esthetic outcome, treatment duration, and success and failure rate were investigated in relation to the initial position of the maxillary canine as assessed on pretreatment panoramic radiographs (vertical and anteroposterior sector position and angulation of the canine [α-angle]). The esthetic evaluation was performed using the Maxillary Canine Aesthetic Index. The success of treatment was defined as achieving a fully functional eruption of the canine, with an esthetically excellent result, without the need for reinterventions. Failure of treatment was defined as the need for reintervention or removal of the canine.

RESULTS

In 96% of the impacted canines, a successful orthodontically assisted eruption was achieved. Age, vertical distance, and angulation are predictors of the esthetic outcome of impacted canines after treatment. Age, bilateral impaction, sector, vertical distance, and angulation are predictors of treatment duration. Age, vertical distance, and buccolingual position are predictors of the need for reintervention.

CONCLUSIONS

Pretreatment radiographic variables can help in predicting the outcome and treatment duration of surgically exposed maxillary impacted canines.

Double vs single primary tooth extraction in interceptive treatment of palatally displaced canines

OBJECTIVES

To compare the impact of primary canine and primary first molar extractions with extractions of only the primary canine regarding correction of palatally displaced canines (PDCs).

MATERIALS AND METHODS

Thirty-two children aged 9.5-13.5 years with 48 PDCs were randomly allocated to either the double-extraction group (DEG) or single-extraction group (SEG). Clinical and radiographic examinations were performed at baseline and at 6-month intervals until the canine emerged or orthodontic treatment was started. Outcome measures were: emergence of maxillary canine (yes/no), emergence of maxillary canine into a favorable position (yes/no), and maxillary canine positional change (angulation and sector). Factors influencing PDC emergence were analyzed using logistic regression.

RESULTS

In the DEG, 64% (16/25) of canines emerged into the oral cavity vs 78% (18/23) in the SEG (P = .283). Favorable PDC position at trial end was seen in 64% (16/25) of the DEG vs 57% (13/23) of the SEG (P = .600). Significant distal movement of PDCs was recorded in the DEG and SEG, though no significant difference was observed between groups. Significant predictors of canine emergence were initial canine angulation (Angle A) (P = .008) and space conditions at T0 (P = .030).

CONCLUSIONS

Double or single primary tooth extraction procedures are equivalent in supporting PDC eruption into the oral cavity and into a favorable position in the dental arch. Initial canine angulation and space assessments may be used as predictors of successful PDC eruption.

Variables to predict spontaneous eruption of palatally displaced permanent canine after interceptive extraction of primary canine: A systematic review and meta-analysis

OBJECTIVE

To evaluate the effectiveness of different diagnostic variables measured on panoramic radiographs (PAN) to predict spontaneous eruption of palatally displaced canine (PDC) after interceptive extraction in late mixed dentition.

MATERIALS AND METHODS

Digital databases (MEDLINE, CENTRAL (Cochrane), Scopus, clinicaltrials.gov, ISRCTN registry) and hand searches were performed up to March 2020. Both randomized and non-randomized controlled trials were considered for the review. Study selection, data extraction, risk of bias assessment (RoB2.0 and ROBINS-I), and the certainty of evidence evaluation (GRADE) were performed according to Cochrane Handbook for Systematic Reviews of Interventions. The random-effects method for quantitative synthesis of dichotomous as well as continuous data was used.

RESULTS

Out of 767 retrieved records, 4 controlled trials fulfilled the eligibility criteria and were included in the review. Studies were assessed at low risk of bias except one. Overall certainty was strong to moderate. PDCs in distal sectors (RR: 1.621; 95%CI: 1.259 to 2.086; P<0.001) and alpha-angle <30° (SMD: -1.350; 95%CI: 1.924 to -0.776; P<0.001) were significantly benefited from interceptive extraction. However, Vertical distance of PDC cusp tip from occlusal plane had statistically insignificant (p: 0.855) roll on eruption prediction.

CONCLUSION

Interceptive extraction at a younger age, initial horizontal localization (sector position), and alpha-angle (initial mesial inclination) are the most important variables predicting the spontaneous eruption of palatally displaced canines. Findings of this review can be utilized to make evidence-based decisions for managing PDCs with diverse sectors and mesial inclinations. However, well-designed clinical trials are recommended to strengthen the evidence.

Mesiodistal Angulation of Each Whole Tooth in Patients With Nonsyndromic Unilateral Cleft Lip and Palate: Is it Symmetrical?

OBJECTIVE

To assess the symmetry of the mesiodistal angulations of maxillary and mandibular teeth in patients with unilateral cleft lip and palate (UCLP) and compare with the class I control group without cleft lip and palate (CLP).

DESIGN

A retrospective study.

SETTING

University department.

PATIENTS, PARTICIPANTS

The panoramic radiographs of 45 orthodontically untreated individuals with nonsyndromic UCLP (mean age 14.13 ± 0.75 years) and 45 skeletal class I individuals without CLP (mean age 14.01 ± 0.74 years).

INTERVENTIONS

The line passing through the most superior points of the condyles was taken as the reference. The angle between the long axes of the maxillary and mandibular teeth and reference line was measured digitally. With the purpose of determining condylar symmetry, mandibular asymmetry index measurements were utilized. Independent samples t test and paired samples t test were used for the statistical analyses.

MAIN OUTCOME MEASURE(S)

The mesiodistal angulation of the maxillary and mandibular teeth in patients with UCLP was measured. The differences between the contralateral sides were determined and compared to class I individuals without CLP.

RESULTS

No statistically significant difference was found among the condylar asymmetry in both groups (P > .05).The significant differences between the cleft and noncleft sides in the UCLP group was observed in the maxillary central, canine, first premolar and second molar teeth (P < .001, P = .002, P = .013, P = .012, respectively). The mean differences were found to be higher in the central and lateral incisors, canines and first premolars in the UCLP group (P < .001, P = .006, P = .001, respectively).

CONCLUSIONS

Although the cleft-side maxillary central incisors tipped in a distal direction in patients with UCLP, the canine and first premolar showed more inclinations toward the mesial direction.

Matrine enhances osteogenic differentiation of bone marrow-derived mesenchymal stem cells and promotes bone regeneration in rapid maxillary expansion

OBJECTIVE

The aim of this study was to evaluate the influence of matrine on osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells (BMSCs) as well as on bone metabolism in a rat rapid maxillary expansion (RME) model.

METHODS

In in vitro experiments, rat BMSCs were adopted and cell proliferation of BMSCs was measured. Meanwhile, the osteogenic differentiation of BMSCs was detected by alkaline phosphatase (ALP) activity assay, Alizarin red S staining and gene expression. In vivo bone regeneration was analyzed in a rat RME model. Eighteen rats were divided into 3 groups: one group without any treatment, one group receiving only RME, and a group with RME and matrine treatment. After 2 weeks, new bone formation was detected by Micro-CT and histology. Immunohistochemical staining was used to evaluate ALP and BMP2 expression.

RESULTS

Overall, we found that matrine upregulated cell proliferation dose-dependently. Also, ALP activity and mineralized matrix generation were enhanced. Moreover, the osteoblast-related gene expression (ALP, bone sialoprotein and osteocalcin) by BMSCs was also promoted. Micro-CT revealed that matrine significantly promoted in vivo bone formation after 2 weeks. Concomitantly, histological examination of haematoxylin-eosin, safranin-O and toluidine blue staining confirmed these findings. In addition, the levels of ALP and BMP2 in the palatal suture tissues of rats with matrine treatment were the highest among three groups.

CONCLUSION

This work suggests that matrine regulates osteogenesis and enhances bone regeneration. Matrine treatment may be beneficial in improving the stability of maxillary expansion.

Inter-premolar width changes related to the orthodontic traction of maxillary impacted canines in adolescents and young adults: A retrospective CBCT study

OBJECTIVE

Maxillary canine impaction is directly associated with a narrow maxillary arch, mainly in the inter-premolar widths. This study compared the transverse changes at the level of maxillary premolars after traction of maxillary impacted canines (MICs) in adolescents and young adults through three main goals: to compare unilateral versus bilateral cases, to compare buccally versus palatally MIC cases, and to compare the affected versus non-affected side exclusively in the unilateral group.

METHODS

This before and after CBCT study involved 45 MIC orthodontically tractioned until the occlusal plane with a standardized protocol. The sample was classified regarding the impaction type (unilateral versus bilateral), impaction location (palatal versus buccal) and the affected versus unaffected sides in the unilateral cases. MIC characteristics as impaction sector, height, and complexity of the traction, as well as α and β angles, canine root length and area were measured. Moreover, cephalometric characteristics were also evaluated. Mann-Whitney U or Wilcoxon signed-rank tests and multiple regressions were applied (α=0.05).

RESULTS

Maxillary inter-premolar widths (first or second) expanded approximately 3mm after traction of unilateral or bilateral MIC (P>0.05). Changes in hemi-arch widths between palatal (1.67mm) versus buccal (1.90mm) MIC were similar (P>0.05). In unilateral impaction, the transversal changes on the affected side were 2mm versus almost 1mm observed in the unaffected side (P<0.05). Finally, the multiple linear regressions were identified to the ANB angle, the impaction sectors and the distance from middle raphe to the cusp tip of MIC as influential variables.

CONCLUSION

The maxillary inter-premolar widths increase after traction of MIC without differences between type or location of impaction. In addition, the transverse change in the affected side in unilateral MIC is greater than the unaffected side resolving the earlier transverse asymmetry.

Orthodontic traction of impacted maxillary canines using segmented arch mechanics

The principles of orthodontic mechanics strongly influence the success of impacted canine traction. The present study discusses the main imaging exams used for diagnosis and localization of impacted canines, the possible associated etiological factors and the most indicated mechanical solutions.

Effectiveness of various interceptive treatments on palatally displaced canine-a systematic review

OBJECTIVE

The aim of this systematic review was to assess whether interceptive treatment carried out in the mixed dentition period improves the position of Palatally Displaced Canines (PDC).

MATERIALS AND METHODS

A systematic search was performed on various computerized databases. A hand search was also performed by reviewing the references within the examined studies and titles of the papers published over the last 30 years on various orthodontic journals.

RESULTS

This systematic review analysed eight articles, of which five were Randomized Clinical Trials (RCT) and three were prospective control studies. Qualitative assessment was done for all the eight studies. The effect of interceptive measures such as extraction of primary canine, Rapid Maxillary Expansion (RME), cervical pull headgear and Transpalatal Arch (TPA) on successful eruption of Palatally Displaced Canines was analyzed.

CONCLUSION

Interceptive treatment improves the position of PDC and reduces the chances of impaction. Significant changes in success rate depend on diagnosis at early mixed dentition stage. A combination of interceptive measures which includes extraction of primary canine, cervical pull headgear, TPA and RME aided in successful eruption. However, Randomized clinical trials with increased sample size, proper randomization comparing all the interceptive measures along with assessment of other factors such as patient satisfaction, pain experience and cost factor will yield more evidence based conclusions.

Prevalence of maxillary canine impaction in skeletal Class III malocclusions compared to Class I malocclusions

Background

The aim of the present investigation was to evaluate if an orthodontic population of Class III malocclusion patients shows a different prevalence of maxillary canine impaction than Class I subjects.

Material and Methods

Fifty-eight subjects were retrospectively selected and assigned to the Class I group (n= 32) or the Class III group (n= 26), depending on the ANB and WITS values. Lateral cephalograms were used to collect angular and linear measurements that described the skeletal and dental maxillary features of the subjects, while orthopantomography was used to assess the impaction or the correct eruption of the maxillary canines. An independent samples T-test or a Mann-Whitney U-test was used to compare the cephalometric values between the two groups, while a chi-squared test was used to evaluate the distribution of maxillary canine impaction between the two groups.

Results

No statistically significant difference was found for the cephalometric variables, and the frequency of canine impaction showed no difference between the Class III and Class I subjects.

Conclusions

Patients with skeletal Class III malocclusions did not show a different prevalence of canine impaction; therefore, such skeletal features cannot be used as a diagnostic aid for assessment of the risk of maxillary canine impaction. Key words:Skeletal Class III, Angle Class III, maxillary canine impaction, tooth impaction.

WITHDRAWN: Extraction of primary (baby) teeth for unerupted palatally displaced permanent canine teeth in children

BACKGROUND

The permanent canine tooth in the maxillary (upper) jaw sometimes does not erupt into the mouth correctly. In about 1% to 3% of the population these teeth will be diverted into the roof of the mouth (palatally). It has been suggested that if the primary canine is removed at the right time this palatal eruption might be avoided. This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To evaluate the effect of extracting the primary maxillary canine on the eruption of the palatally ectopic maxillary permanent canine.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 20 April 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 1), MEDLINE via OVID (1946 to 20 April 2012) and EMBASE via OVID (1980 to 20 April 2012). There were no restrictions regarding language or date of publication.

SELECTION CRITERIA

Trials were selected if they met the following criteria: a randomised or quasi-randomised controlled trial, involving the extraction of the deciduous maxillary canine and assessing eruption/non-eruption of the palatally displaced maxillary permanent canine.

DATA COLLECTION AND ANALYSIS

Data extraction was undertaken independently by two review authors. The primary outcome was the reported prevalence of eruption or non-eruption of the ectopic permanent canine into the mouth following observation or intervention. Results were to be expressed as risk ratios for dichotomous outcomes with 95% confidence intervals and mean differences for continuous outcomes. Heterogeneity was to be investigated, including both clinical and methodological factors. Authors of trials were contacted to request unpublished data.

MAIN RESULTS

Reports of two randomised controlled trials previously excluded from an earlier version of the review due to "deficiencies in reporting, insufficient data" have now been included. These two trials included approximately 128 children, with more than 150 palatally displaced canine teeth, and both were conducted by the same research group. Data presented in the trial reports are either incomplete or inconsistent. Both trials are at high risk of bias. It must be emphasised that both trials have serious deficiencies in the way they were designed, conducted, and reported, and attempts to contact the authors to obtain detailed information and clarify inconsistencies have been unsuccessful. Allocation to treatment appears to be at the level of the individual, but outcomes of successful treatment relate to included teeth and data are not reported for each treatment group. Adverse effects are not reported. Neither trial provides any evidence to guide clinical decision making.

AUTHORS' CONCLUSIONS

There is currently no evidence of the effects of extraction of primary canine teeth in 10-13 year old children with one or two palatally displaced permanent canine teeth.

[Effects of maxillary disjunction on canine impaction in patients presenting a maxillary transverse skeletal deficiency]

INTRODUCTION

This study focuses on the effects of rapid maxillary disjunction on the tendency to canine impaction in patients displaying a maxillary transverse skeletal deficiency.

MATERIALS AND METHODS

Using the segmentation method described by Ericson and Kurol and modified by Lindauer, et al., a series of panoramic views taken before and after disjunction was studied to compare changes in the position of the tip of the maxillary canine depending on whether it was covered or not by the homolateral lateral incisor, according to the side and patient's sex. The cohort consisted of 193 patients, all treated using a palatal expander welded to bands.

RESULTS

A statistically significant improvement was observed in all categories regarding the position of the maxillary canine. Disjunction was successful in 87% of cases in our sample. No significant differences were found according to side or sex.

Maxillary first premolar inclination in 8- to 11-year-old children: An observational cross-sectional study on panoramic radiographs

INTRODUCTION

In this study, we examined first premolar inclination in a large sample.

METHODS

First premolar inclination, canine inclination, and mesiodistal location were measured on 797 panoramic radiographs of orthodontically untreated children (ages, 8-11 years; 381 boys, 416 girls). The sample comprised 1496 premolars and 1496 canines. A linear mixed-effects model was used to determine the contribution of age, sex, canine inclination, canine sector location, second molar maturational stage (D-G), and dental arch side on premolar inclination.

RESULTS

First premolar inclination values (medians and interquartile ranges) were 12.76° (8.12°-19.05°) at 8 years, 11.82° (7.87°-16.04°) at 9 years, 10.40° (6.38°-15.46°) at 10 years, and 9.03° (5.42°-12.81°) at 11 years; 13.86° (8.60°-18.78°) at stage D, 10.56° (7.39°-14.77°) at stage E, 10.43° (6.08°-15.09°) at stage F, and 8.00° (4.62°-10.74°) at stage G. The following equation was selected (Akaike information criteria = 424.99): first premolar inclination (°) = -2.211 + 2.240 (8 years) + 1.363 (9 years) + 0.955 (10 years) + 0.387 (canine inclination) + 0.902 (right side) + 2.320 (stage D) + 6.320 (sector 1) + 5.446 (sector 2) + 3.803 (sector 3). There was no difference between percentiles constructed by age and maturational stage.

CONCLUSIONS

First premolar inclination decreases during the mixed dentition and is moderately correlated with canine inclination.

Use of self-organizing maps for analyzing the behavior of canines displaced towards midline under interceptive treatment

Background

Displaced maxillary permanent canine is one of the more frequent findings in canine eruption process and it’s easy to be outlined and early diagnosed by means of x-ray images. Late diagnosis frequently needs surgery to rescue the impacted permanent canine. In many cases, interceptive treatment to redirect canine eruption is needed. However, some patients treated by interceptive means end up requiring fenestration to orthodontically guide the canine to its normal occlusal position. It would be interesting, therefore, to discover the dental characteristics of patients who will need additional surgical treatment to interceptive treatment.

Material and Methods

To study the dental characteristics associated with canine impaction, conventional statistics have traditionally been used. This approach, although serving to illustrate many features of this problem, has not provided a satisfactory response or not provided an overall idea of the characteristics of these types of patients, each one of them with their own particular set of variables. Faced with this situation, and in order to analyze the problem of impaction despite interceptive treatment, we have used an alternative method for representing the variables that have an influence on this syndrome. This method is known as Self-Organizing Maps (SOM), a method used for analyzing problems with multiple variables.

Results

We analyzed 78 patients with a PMC angulation higher than 100º. All of them were subject to interceptive treatment and in 21 cases it was necessary to undertake the above-mentioned fenestration to achieve the final eruption of the canine.

Conclusions

In this study, we describe the process of debugging variables and selecting the appropriate number of cells in SOM so as to adequately visualize the problem posed and the dental characteristics of patients with regard to a greater or lesser probability of the need for fenestration.

Key words:Interceptive orthodontic treatment, altered eruption, impacted canines, neuronal networks, self-organizing maps.

Risk of developing palatally displaced canines in patients with early detectable dental anomalies: a retrospective cohort study

The early recognition of risk factors for the occurrence of palatally displaced canines (PDC) can increase the possibility of impaction prevention.

A comparison of three-dimensional stress distribution and displacement of naso-maxillary complex on application of forces using quad-helix and nickel titanium palatal expander 2 (NPE2): a FEM study

Background

Our objectives are to analyse and to compare the stress distribution and displacement of the craniofacial structures, following the application of forces from quad-helix and Nickel Titanium Palatal Expander-2 (NPE2) using finite element analysis.

Methods

Three-dimensional finite element models of young dried human skull, quad-helix appliance and NPE2 were constructed, and the initial activation of the expanders was stimulated to carry out the analysis and to evaluate the Von Misses stresses and displacement.

Results

Both the models demonstrated the highest stresses at the mid-palatal suture, with maximum posterior dislocation. The second highest stress was recorded at the fronto-zygomatic suture. The pattern of stress distribution was almost similar in both the groups, but NPE2 revealed lower magnitude stresses than quad-helix. The only exception being quad-helix model showed high stress levels around pterygo-maxillary suture whereas minimal stress around pterygo-maxillary suture was noticed after NPE2 activation. The cusp of the erupting canine and the erupting mesiobuccal cusp of the second molar showed outward, backward and downward displacement signifying increase in their eruption pattern following maxillary expansion.

Conclusions

Maxillary expansion using quad-helix and NPE2 can be used in posterior crossbite correction in cases where maximum skeletal changes are desirable at a younger age; it is furthermore effective in treating young patients with impacted or displaced teeth. Quad-helix and NPE2 produced acceptable forces for orthopaedic treatment even after being orthodontic appliances; their clinical application should be correctly planned as the effects of these appliances are largely age dependent.

Early prediction of maxillary canine impaction

OBJECTIVES

The aim of this study was to establish prediction criteria for maxillary canine impaction in young patients, based on angular and linear measurements on panoramic radiographs.

METHODS

From 828 records having at least 2 panoramic radiographs, both taken between the ages of 7 and 14 years, with a minimum 1-year and maximum 3-year interval (T1 and T2), a training data set consisting of 30 subjects with unilateral canine impaction (12 males and 18 females) was selected. The patients' mean age was 10.1 years [standard deviation (SD) 1.3 years] at T1 and 11.9 years (SD 1.1 years) at T2. The training data set also consisted of 30 maxillary canines from the contralateral sides and an additional 60 normal erupted canines from 30 subjects. Those 30 subjects of a test data set were selected based on displaying bilateral maxillary canine eruption at T2 and being matched for gender and age with the subjects of the training data set [12 males and 18 females; mean age at T1, 10.1 years (SD 1.3 years) and at T2, 11.1 years (SD 1.2 years)]. Angular and linear measurements were performed separately by two observers on the total study sample at T1. Linear measurements were expressed as a multiplication of the maxillary central incisor width at the non-impacted side.

RESULTS

Significant differences for linear and angular measurements and radiographic factors were found between the maxillary impacted canine and erupted maxillary canine. The three best-discriminating parameters were canine to first premolar angle, canine cusp to midline distance and canine cusp to maxillary plane distance. These three parameters were combined in a multiple logistic regression model to calculate the probability of impaction, yielding a high area under the curve (AUC) equal to 0.97 (95% confidence interval: 0.94-0.99), with 90% sensitivity and 94% specificity.

CONCLUSIONS

Prediction of maxillary canine impaction from a combination of parameters relating to angles and distances measured in panoramic radiographs is weak. However, the final prediction model, based on canine-first premolar angle, canine cusp tip to midline distance and canine cusp tip to maxillary occlusal plane distance, might be useful to discriminate canine impaction for early intervention or regular follow-up.

Root resorptions related to ectopic and normal eruption of maxillary canine teeth - A 3D study

OBJECTIVE

To assess the incidence and severity of root resorption of maxillary incisors caused by ectopically and normally erupting maxillary canines and to analyse factors influencing root resorption of incisors using cone beam computed tomography.

SUBJECTS AND METHODS

The study sample comprised 59 patients with a total of 80 canines. Forty-six of the canines, in 37 patients, were defined as ectopic and 34 canines, in 22 patients, were defined as normal. The severity of root resorptions were analysed according to studies by Ericson and Kurol. Multiple logistics regression was used to evaluate the association between various factors and root resorptions.

RESULTS

The prevalence of root resorptions was significantly higher in the ectopic canine group, 11.0% of the central incisors and 67.6% of the lateral incisors in comparison to 0% and 36.2% in the normal erupting group. Most resorptions were defined as 'slight' and were located in the middle third of the root. There was a statistically significant relationship between canines located mesial to the midline of the lateral incisor and root resorption on the maxillary incisors.

CONCLUSION

The present results show that root resorption of maxillary lateral incisors was common in patients referred to CBCT imaging due to maxillary canine eruption disturbances. Although significantly more frequent in patients with ectopically erupting canines, lateral incisor resorption was also found in association with approximately every third of the normally erupting canines. The best predictor for root resorption seemed to be location of the canine mesial in relation to the midline of the lateral incisor root.

Predictive variables derived from panoramic radiographs for impacted maxillary cuspids treated with easy cuspid system

The aim of the current study was to find, by means of panoramic radiographs, a viable statistical method to forecast the duration of orthodontic traction of impacted maxillary cuspids. The treatment sample consisted of 51 palatal impacted cuspids (19 unilateral and 32 bilateral) in 35 patients (aged between 10.5 and 17.5 y) with a cervical vertebral maturation between cervical stage 1 and 4. Each patient underwent the same combined surgical-orthodontic technique. Anamnestic data as well as pretreatment panoramic radiograph and cephalogram with European Board of Orthodontics analysis were recorded for each case. Eight radiographic indicators were derived from panoramic films to define the reliable position of the impacted cuspid. Multiple regression analysis was used. All cuspids were successfully treated with an average traction time of 99 days (range, 33-188 d). The pretreatment radiographic features assessed on the panoramic radiographs did not significantly affect the duration of traction. The formula based on α angle, d1 distance, and S sector forecasted an average traction time of 123 days (range, 63-210 d), which is longer than the real time. No relevant correlations were found between orthodontic traction time and pretreatment radiograph parameters derived from panoramic film at the beginning of the treatment. The classic formula elaborated by Crescini could not be applied to the patients of this study, who were treated with the Easy Cuspid method.

Extraction of primary (baby) teeth for unerupted palatally displaced permanent canine teeth in children

BACKGROUND

The permanent canine tooth in the maxillary (upper) jaw sometimes does not erupt into the mouth correctly. In about 1% to 3% of the population these teeth will be diverted into the roof of the mouth (palatally). It has been suggested that if the primary canine is removed at the right time this palatal eruption might be avoided. This is an update of a Cochrane review first published in 2009.

OBJECTIVES

To evaluate the effect of extracting the primary maxillary canine on the eruption of the palatally ectopic maxillary permanent canine.

SEARCH METHODS

We searched the following electronic databases: the Cochrane Oral Health Group's Trials Register (to 20 April 2012), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 1), MEDLINE via OVID (1946 to 20 April 2012) and EMBASE via OVID (1980 to 20 April 2012). There were no restrictions regarding language or date of publication.

SELECTION CRITERIA

Trials were selected if they met the following criteria: a randomised or quasi-randomised controlled trial, involving the extraction of the deciduous maxillary canine and assessing eruption/non-eruption of the palatally displaced maxillary permanent canine.

DATA COLLECTION AND ANALYSIS

Data extraction was undertaken independently by two review authors. The primary outcome was the reported prevalence of eruption or non-eruption of the ectopic permanent canine into the mouth following observation or intervention. Results were to be expressed as risk ratios for dichotomous outcomes with 95% confidence intervals and mean differences for continuous outcomes. Heterogeneity was to be investigated, including both clinical and methodological factors. Authors of trials were contacted to request unpublished data.

MAIN RESULTS

Reports of two randomised controlled trials previously excluded from an earlier version of the review due to "deficiencies in reporting, insufficient data" have now been included. These two trials included approximately 128 children, with more than 150 palatally displaced canine teeth, and both were conducted by the same research group. Data presented in the trial reports are either incomplete or inconsistent. Both trials are at high risk of bias. It must be emphasised that both trials have serious deficiencies in the way they were designed, conducted, and reported, and attempts to contact the authors to obtain detailed information and clarify inconsistencies have been unsuccessful. Allocation to treatment appears to be at the level of the individual, but outcomes of successful treatment relate to included teeth and data are not reported for each treatment group. Adverse effects are not reported. Neither trial provides any evidence to guide clinical decision making.

AUTHORS' CONCLUSIONS

There is currently no evidence of the effects of extraction of primary canine teeth in 10-13 year old children with one or two palatally displaced permanent canine teeth.