To what extent are impacted canines associated with root resorption of the adjacent tooth?: A systematic review with meta-analysis

Survival of retained permanent canines after autotransplantation: A retrospective cohort study

INTRODUCTION

After third molars, canines are the teeth most commonly affected by displacement and impaction. Although orthodontic surgical treatment represents the standard method for realignment of canines, autotransplantation (autoTX) functions as the second-line therapy if orthodontic alignment does not succeed in treating impaction and severe displacement. This retrospective cohort study aimed to identify clinical predictors for postoperative survival and endodontic treatment needs after autoTX of severely displaced and impacted canines.

METHODS

The study cohort comprised patients who received canine autoTX in a single surgical center between 2006 and 2018. Canines with severe displacement and retention were surgically treated using a standardized protocol. Statistical analysis of survival probability was performed with the Kaplan-Meier method, and bivariate data were analyzed using logistic regression and the Pearson chi-square test. Nonparametric continuous variables were analyzed using the Mann-Whitney U test.

RESULTS

Data from 319 patients with 378 canine grafts were available for analysis after a mean follow-up of 54.7 ± 36.5 months on the patient level (range, 0.3-181.8 months). With 25 lost autotransplants, the cumulative survival rate was 93.4%. Patient age at surgery, the state of the apical foramen, endodontic treatment need, and persistence of deciduous teeth at the implantation site had a significant negative impact on autotransplant survival (P <0.05). Endodontic treatment need was significantly related to the patient's age at surgery, the state of the apical foramen, and preoperative orthodontic traction (P <0.05). Thus, these independent variables were identified as clinical predictors for the survival of both the autotransplant and the dental pulp. Gender, ischemia time, postoperative ankylosis, or site of autoTX did not influence any of the outcome variables.

CONCLUSIONS

The high survival rates of autotransplanted permanent canines make this treatment a promising option, especially in patients with severe tooth displacement, in which orthodontic treatment alone cannot provide predictable alignment, irrespective of the patient's age. Interpreting age and preoperative orthodontic traction as delaying the onset of autoTX and state of apex, time-dependent aspects seem to be of great importance for postoperative complications leading to endodontic treatment or graft loss. Therefore, early implementation of autoTX as a treatment modality for impacted, severely displaced, and vain exposed canines in daily surgical practice should be encouraged.

Long-term follow-up after the treatment of impacted canines in the maxilla causing severe root resorption of the lateral incisors: two case reports

BACKGROUND

Root resorption of adjacent teeth due to impacted canines is common, and orthodontic treatment often leads to secondary resorption or even loss of adjacent roots. Clinical reports of long-term stability after treatment are rare.

CASE PRESENTATION

This study reports two cases of maxillary impacted canines resulting in severe root resorption of the adjacent lateral incisors. Surgical exposure, orthodontic retraction, and alignment of the impacted canines were successful in both cases, and the resorbed lateral incisors were stable with no significant loosening and normal pulp vitality after treatment and at the 5- and 10-year follow-up appointments.

CONCLUSIONS

Light orthodontic force may be used to move adjacent teeth with root resorption due to tooth obstruction. The path and direction in which the teeth are moved must be specifically designed so that the adjacent roots are not resorbed and so long-term stability can be achieved.

Influence of alveolar bone thickness and bucco-palatal inclination on root resorption of lateral incisors in unilateral maxillary impacted canines: a retrospective observational study

BACKGROUND

This study aimed to investigate the potential associations between alveolar bone thickness, bucco-palatal inclination of maxillary lateral incisors, and lateral incisor root resorption in patients with unilateral maxillary impacted canines (UMICs).

METHODS

A total of three hundred and five subjects (120 males, 185 females; mean age, 16.39 years; standard deviation, 4.04) with UMICs were included. Canine position and root resorption were assessed using CBCT. UMICs were divided into palatal, buccal and mid-alveolus groups (PICs, BICs and MAICs), with 117, 137 and 51 subjects, respectively. Alveolar bone thickness and bucco-palatal inclination of lateral incisors were measured using the Dolphin software.

RESULTS

The prevalence of lateral incisor root resorption was significantly lower in the BICs (13.9%) than MAICs (29.4%) and PICs (29.1%). Alveolar bone thickness of the apical area was smaller in UMICs with lateral incisor root resorption than no resorption in both PICs (8.33 ± 1.64 vs 10.53 ± 2.55 mm) and BICs (8.94 ± 1.85 vs 10.76 ± 2.28 mm). Furthermore, lateral incisors on the impacted side were more buccally inclined in PICs with lateral incisor root resorption than no resorption, while in both BICs and MAICs, there was no statistical difference between lateral incisor root resorption than no resorption. Moreover, alveolar bone thickness of the apical area, rather than bucco-palatal inclination of lateral incisors, was significantly correlated with lateral incisor root resorption both in PICs and BICs.

CONCLUSIONS

Lateral incisor root resorption is less common in BICs. Thinner alveolar bone thickness at the apical area of lateral incisors can be considered as a potential risk factor for lateral incisor root resorption in UMICs.

Apical incisor root resorption due to ectopic maxillary canine eruption: Association with time of diagnosis and type of intervention in a retrospective population-based cohort study

OBJECTIVES

The primary aim was to study upper incisor severe apical root resorption (RR) related to ectopic canine eruption and its association with timing of diagnosis and type of intervention conducted. The secondary aim was to correlate resorption with other dental anomalies.

MATERIALS AND METHODS

Digital journals and radiographic material of all ectopic maxillary canines registered in 2012 in the regional public paediatric dental clinics in the Council of Aarhus were inspected retrospectively. Data related to 10 variables were retrieved. Post-treatment radiographs were used for evaluation of incisor RR.

RESULTS

A total of 260 ectopic maxillary canines were diagnosed in 2012. The majority were found in the 9-13-year-old age group (0.8% prevalence within the total population). In all, 244 canines were assessed for eligibility and 181 had adequate final radiographs for evaluation of RR. Among ectopic maxillary canines, 9.4% caused severe incisor RR to neighbouring teeth. Timely palpation for canine eruption significantly reduced the odds for upper incisor resorption by 80%. Multiple regression showed that when the permanent canine cannot be palpated and the deciduous has been extracted, delaying the first X-rays was associated with a 38% odds ratio increase for RR for each year of delay after the age of 10 years. No significant associations were found between incisor RR and intervention conducted or other dental anomalies.

CONCLUSION

Palpation of erupting maxillary canines is crucial for timely diagnosis of ectopic eruption and initiation of treatment to avoid RR. If the canine cannot be palpated at 10 years of age, radiographic examination is highly recommendable.

Challenges of a two-phase orthodontic treatment of a mandibular lateral incisor-canine transposition and a maxillary palatally displaced canine: A case report

INTRODUCTION

The management of eruption disturbances in orthodontics may be challenging and requires a careful diagnosis and treatment planning. This case report discusses the challenges of a two-phase orthodontic treatment of a patient presenting with a dental eruption pattern anomaly.

PATIENT CONCERNS

A 10-year-old boy was presented with no complaints for a routine orthodontic evaluation during mixed dentition.

PRIMARY DIAGNOSES

The patient was diagnosed with a skeletal Class I malocclusion with unilateral posterior crossbite, incomplete mandibular lateral incisor-canine transposition and a unilateral maxillary ectopic canine.

INTERVENTIONS

Phase 1 started with rapid maxillary expansion to correct maxillary constriction and the ectopic eruption of the right maxillary canine. In the mandibular arch, phase 1 included the extraction of the left primary lateral incisor and canine, alignment of the left permanent lateral incisor and orthodontic traction of the left permanent canine. The duration of phase 1 was 14 months. Phase 2 involved a comprehensive course of orthodontic treatment and started when the patient was aged 13 years. This phase lasted 18 months.

RESULTS

An adequate dental occlusion was obtained, and the treatment results were stable after an 18-month follow-up.

CONCLUSION

In this case, the early diagnosis of the dental anomalies was valuable as it allowed an early intervention to be undertaken, which resulted in overall treatment simplification and potentially minimised the adverse effects. This case report reinforces the importance of a careful follow-up during mixed dentition.

Modified alveolar ridge preservation to promote the osteogenesis of the distal surface of second molar after mandibular impacted third molar extraction: a preliminary study

OBJECTIVES

The objective of the retrospective study was to explore whether the use of a modified alveolar ridge preservation technique impacts osteogenesis on the distal surface of the second molar after mandibular third molar (M3) extraction.

MATERIALS AND METHODS

A total of 54 patients were enrolled in this study and divided into three different groups, including modified alveolar ridge preservation (MARP) group, traditional tooth extraction (TRA) group, and classical guided bone regeneration (GBR) group. In this study, MARP was designed with the highlights of the preservation of the alveolar bone superior and lingual to M3. These patients chose different surgical methods according to their own wishes for past infection or in order to prevent pericoronitis, and the operation time and surgical cost of each group were recorded. The periodontal conditions of the ipsilateral mandibular second molar (M2) and the height of its distal alveolar bone were measured during the postoperative follow-up.

RESULTS

The probing depth, clinical attachment level, and osseous defect depth on the distal surface of the ipsilateral M2 in the MARP group were better than those of the TRA group at any time of the follow-up (P < 0.05 for all), but there was no statistical difference in the measurements when compared to the GBR group at 6 months after operation (P > 0.05 for all).

CONCLUSIONS

Thus, MARP therapy not only improves the regeneration of periodontal osseous defects distal to the M2 after M3 extraction but also reduces the operation time and surgical cost.

CLINICAL RELEVANCE

This paper introduces a modified surgical method that can not only economically and effectively remove the impacted mandibular third molar but also obtain stable osteogenesis.

Three-dimensional decision support system for treatment of canine impaction

INTRODUCTION

This study aimed to develop a 3-dimensional (3D) characterization of the severity of maxillary impacted canines and to test the clinical performance of this characterization as a treatment decision support tool.

METHODS

Cone-beam computed tomography images obtained from 83 patients with 120 impacted maxillary canines were included. Quantitative information on the canine 3D position and qualitative assessment of root damage of adjacent teeth were evaluated. A severity index was constructed on the basis of the quantitative findings. Clinical applicability was tested by comparing clinical diagnosis and treatment planning for conventional records vs the 3D characterization via a 2-part survey.

RESULTS

The average quantitative assessments of impacted maxillary canine position were 6.4 ± 3.6 mm from the midsagittal plane, 11.6 ± 3.1 mm in height relative to the occlusal plane, 31.5° ± 18° of roll, and 48.8° ± 14.3° of pitch. The severity index ranged from 0-13 with a mean score of 4.5 ± 2.2. Overlap with adjacent teeth was the greatest contributor (33%) to the index. Bicortically impacted canines caused the most severe root damage. Cone-beam computed tomography was preferred for assessing root damage and overall severity, whereas conventional imaging was sufficient for height and angulation assessment. The 3D report was very important or important for evaluating root damage, canine position, overall severity, and overlap. The 3D report changed most of the decisions relating to biomechanics, patient education, and treatment time estimate. The decision of exposure and traction vs extraction was changed 22% of the time after the presentation of the 3D report.

CONCLUSIONS

The overlap with adjacent teeth frequently contributes the most to the severity index. The 3D report provided relevant clinical information regarding the canine position, damage to adjacent teeth, and the severity index, with a profound impact on the decisions of the clinicians regarding biomechanics, patient education, and treatment time estimate.

Root Resorption of the Permanent Central Incisor through Ectopic Eruption of the Maxillary Canine

Although ectopic eruption of the maxillary canine has a low prevalence, a late diagnosis can have serious consequences. A careful clinical examination, assisted with radiographic examination, ensures early diagnosis, facilitates planning, and minimizes possible adverse consequences. This study reports a case of ectopic eruption of the permanent maxillary canine, with complete root resorption of the central permanent incisor, the consequences of which caused functional, aesthetic, and psychological harms to the patient. The procedures used included canine ectopic remodeling of the ectopic canine in the central incisor and orthodontic correction, which treated the anomaly and rebuilt the patient's self-esteem.

Unilateral vs Bilateral Maxillary Canine Impaction: A Cone-Beam Computed Tomography Study of Patterns and Associations

AIM

This retrospective study aimed to compare and evaluate the pattern of maxillary canine impaction and its association with other anomalies using cone-beam computed tomography (CBCT).

METHODS

A total of 59 CBCT records of patients (ages 12 and up) were divided into two groups: A total of 35 subjects with unilateral canine impactions and 24 subjects with bilateral canine impactions. The CBCT data were analyzed for the measurement of qualitative and quantitative variables.

RESULTS

In unilateral canine impaction, the mesiodistal (MD) width of the central incisors and the nasal cavity (NC) width were wider (p < 0.05). The canine-palatal plane (U3-PP) distance was significantly longer in bilateral canine impaction (p < 0.05). The distance of the impacted canines from the palatal and mid-sagittal planes, the anterior dental arch width, and the maxillary skeletal width changed significantly with the position of the impacted canines (p < 0.05). Males had 0.185 odds of presenting with a bilateral canine impaction as compared to females (p = 0.025). The odds of having bilateral canine impaction with a longer canine-midsagittal plane (U3-MSP) distance was 1.30 (p = 0.003).

CONCLUSION

The findings indicate a gender predilection with females showing a greater prevalence of bilateral canine impaction. Supernumerary teeth were associated with unilateral impacted canines and lower canine impaction with bilaterally impacted canines.

CLINICAL SIGNIFICANCE

Anomalies in the form of the maxillary central and lateral incisors, distance from the maxillary canine to the palatal plane and the mid-sagittal plane, NC width, maxillary skeletal width, and gender, are the best discriminating parameters between unilateral and bilateral canine impactions.

Radiographical characteristics and traction duration of impacted maxillary canine requiring surgical exposure and orthodontic traction: a cross-sectional study

This cross-sectional study aimed to classify the radiographical characteristics of impacted maxillary canines that were surgically exposed following orthodontic traction and to find out which factor is most closely related to traction duration. This study enrolled 74 patients with 87 maxillary canines. Cone-beam computed tomography images, panoramic radiographs, and medical records were analyzed. Cystic-appearing lesion and resorption of adjacent roots were observed in 26.4% and 23.0% of cases, respectively. Impacted maxillary canines were mostly distributed in the lateral incisor area. The mean (± standard deviation) traction duration for the 47 teeth that met the study criteria was 13.9 (± 8.9) months. Impacted maxillary canines treated with surgical exposure and orthodontic traction showed increasing possibilities of palatal impaction and resorption of the adjacent root as they were located mesially (p < 0.05). The distance from the occlusal plane to the impacted maxillary canine showed the strongest positive correlation with traction duration (r = 0.519, p < 0.01). When establishing treatment plans for patients with impacted maxillary canines, distance from the occlusal plane to the impacted canines, rather than the angle, should be considered in predicting the duration of treatment.

Severity and Treatment Difficulty of Impacted Maxillary Canine among Orthodontic Patients in Riyadh, Saudi Arabia

BACKGROUND

The current study aimed to evaluate the severity and treatment difficulty of impacted maxillary canines and their relationship with gender, age group, and bucco-palatal position.

METHODS

A retrospective cross-sectional study was conducted from 2017 to 2021. Patients' data and panoramic radiography were obtained from the orthodontic clinic at King Saud University's Dental University Hospital in Riyadh, Saudi Arabia. The severity factors and treatment difficulty index were used to assess the impacted maxillary canines. Statistical analyses were performed utilizing a chi-square test for categorical variables and an independent t-test for numerical variables, and a p-value of ≤0.05.

RESULTS

There were 171 impacted maxillary canines in total, with a female-to-male subject ratio (11:8) and a mean age (18.7 years). Overall, 77.2% of impacted upper canines were found to be palatal. The severity of canine impaction parameters showed no significant sex or age group predilection. Buccally impacted maxillary canines were characterized by a preferable angulation to the midline, compared to the palatally impacted maxillary canines (p = 0.012). The horizontal overlap of the impacted maxillary canine cusp tip revealed a significant association with the bucco-palatal position of the impacted canine (p < 0.001). Palatal impaction was located more frequently in sectors 3 and 4. Male patients were found to have a higher total score in terms of the treatment difficulty index relative to females (p = 0.046).

CONCLUSION

Despite the severity parameters having revealed no significant gender predilection, males were found to have higher treatment difficulty in maxillary canine impaction than females. The severity of the palatally impacted canine is greater than that of buccal impaction in terms of angulation to the midline and horizontal overlap.

Evaluation of Lateral Incisor Resorption Caused by Impacted Maxillary Canines Based on CBCT: A Systematic Review and Meta-Analysis

Background: Root resorption (RR) of the adjacent teeth due to upper canine impaction requires an appropriate modification of the orthodontic treatment plan and the mechanotherapy used. Aim: The aim of this review was to assess scientific evidence published during the last decade, concerning the prevalence of lateral incisor RR caused by impacted maxillary canines, based only on cone-beam computed tomography (CBCT). The location of RR on this tooth, as well as the prevalence of RR on the other adjacent teeth, were additionally evaluated. Methods: This review followed the criteria specified by the PRISMA statement. Four databases were searched for articles published between January 2008 and June 2021. Predefined and piloted data collection forms were used to record the necessary information. Results: A total of 5098 records were initially screened. Only seven articles were finally eligible for further analysis. A total number of 540 participants (176 males and 364 females) was derived from the included studies. RR of maxillary lateral incisors was common (50%). RR of mild severity was more common (62%), more frequently located in the middle (52%) and apical (42%) thirds of the root. Conclusions: Further research with more homogeneous groups is required.

Predictive factors associated with adjacent teeth root resorption of palatally impacted canines in Arabian population: a cone-beam computed tomography analysis

Background

This study aimed to evaluate three-dimensionally the factors associated with adjacent teeth root resorption of palatally impacted canines.

Methods

In this retrospective cross-sectional study, one-hundred and fourteen cone beam computed tomography scans with palatally impacted maxillary canines were evaluated for the presence of adjacent root resorption. Seven parameters were analyzed: alignment of maxillary incisors, presence of deciduous canines, first premolars’ roots configuration, impacted canines rotation, angulation of impacted canine to the midline, contact relationship, and area of contact with adjacent teeth. The association between dependent and independent qualitative and quantitative variables was analyzed using chi-square and independent student’s t-test, respectively. The multivariate analysis was performed using regression analysis. The significant value was set at P ≤ 0.05.

Results

The overall incidence of vertical, horizontal impaction and adjacent root resorption were 92, 8 and 77.2%, respectively. The apical third was the most involved area (57%); resorption of a single tooth was found in 21.9% of the total sample. The most common resorbed teeth were lateral first premolars (24.6%), followed by central lateral incisors (20.2%), and lateral incisors (15.8%) of the total sample. The severity of resorption was highest in grade I (31.5%) and lowest in grade III (7.6%). Three variables showed significant differences between resorption and non-resorption groups namely; canine rotation (P < 0.013), contact relationship (P < 0.001), and area of contact with adjacent teeth (P < 0.001). Regression analysis revealed an association between adjacent root resorption and permanent canine rotation, adjacent premolars’ roots configuration, contact relationship, and area of contact (P < 0.05).

Conclusion

Two-thirds of impacted maxillary canines showed a form of root resorption. The most commonly resorbed tooth was the lateral incisors while the least affected one was the central incisors with apical one-third being of the highest risk. The predisposing factors including the canine rotation, premolar with separated roots, contact relationship, and area of contact with adjacent teeth are to be considered for any interceptive treatment.

Root Resorptions on Adjacent Teeth Associated with Impacted Maxillary Canines

Aim: Through the use of CBCT images, many unidentified features of impacted canines can be easily resolved. The potential collision of impacted maxillary canines and adjacent teeth could lead to root resorption (RR). The aim of this study is to examine the prevalence, location and severity of RR on adjacent teeth caused by impacted maxillary canines and the association between the adjacent teeth and the features of maxillary impacted canines on CBCT. Methods: This study examined 89 subjects with 108 maxillary impacted canines, having had no previous orthodontic treatment (mean age: 18.3 ± 4.1 years). The following impacted-canine-related parameters were analyzed on the CBCT images: location; RR levels on adjacent teeth; occlusal line and midline distances of impacted canines; and the angulations of impacted canines to the midline, lateral incisor and occlusal line. Logistic regression was used to evaluate the association between RR and the measured parameters on CBCT. Results: In this study, we found that the majority of our patients with impacted maxillary canines were female (62.5%). Of the total 108 maxillary impacted canines, 60.2% resorbed the adjacent teeth of the affected quadrants. Lateral incisors were the most affected (34.3%). The mean age of subjects with RR was 16.7 ± 3.5 years. The frequency of RR was statistically significantly higher in female subjects (40.4%). Slight RR was the most frequent (30.5%) and the highest incidence noted at the apical third of the root (29.6%). Regarding the impacted maxillary canine angulation to the midline and adjacent tooth, higher values of angulation caused severe forms of RR (p < 0.05). Conclusion: The sensitivity of CBCT allows for the accurate diagnosis of the location and the degree of RR, alongside the angulation and distance of impacted canines to adjacent teeth. The association between the linear and angular features of the impacted maxillary canines and RR was confirmed.

Radiographic features in 2D imaging as predictors for justified CBCT examinations of canine-induced root resorption

OBJECTIVES

This retrospective observational study aimed to evaluate the diagnostic accuracy of two-dimensional radiographs on canine-induced root resorption (CIRR) in lateral incisors and identify predictors of CIRR in patients with impacted maxillary canines (IMC).

METHODS

Ninety-nine patients aged 9-17 years, with 156 IMCs, were included in the study. All had CBCT-volumes and two-dimensional radiographs consisting of at least one panoramic radiograph. Two radiologists jointly viewed all cases twice. First, radiographic features related to the IMC and possible CIRR were recorded from two-dimensional radiographs. Then, CIRR was determined from CBCT and according to position and extension classified as mild, moderate and severe.

RESULTS

CIRRs was detected in 80% of lateral incisors (mild: 45%; moderate: 44%; severe: 11%). The sensitivity was generally low at mild and moderate cut-offs (29 and 29%), and somewhat higher for severe (50%). Corresponding specificities were 48%, 63% and 68%. Canine cusp-tip superimposing the lateral incisor's middle third and root/crown ratio >1 was positively associated with mild CIRR, with an odds ratio (OR) of 3.8 and 6.7, respectively. In addition, the root development stage was positively associated with moderate/severe CIRR when the canine root was nearly or fully developed (OR = 3.1).

CONCLUSIONS

The diagnostic accuracy of two-dimensional radiographs was inadequate for detecting CIRR amongst patients referred for CBCT examinations. Based on our results, none of the suggested two-dimensional radiographic features could predict moderate/severe CIRR except for root development stage. IMC in a later stage of root development seems to be associated with a higher risk of moderate/severe CIRR.

Root Resorption of Adjacent Teeth Associated with Maxillary Canine Impaction in the Saudi Arabian Population: A Cross-Sectional Cone-Beam Computed Tomography Study

This study aimed to identify the location of root resorption in relation to an impacted maxillary canine and grade its severity using cone-beam computed tomography (CBCT) in the Saudi Arabian population. Materials and Methods: CBCT scans of 169 patients with maxillary canine impaction were evaluated. The location and the severity of root resorption of the affected tooth in relation to the impacted maxillary canine were recorded for each patient. Results: a total 204 impacted maxillary canines caused root resorption in 218 adjacent teeth. Maximum root resorption was present in 63.3% of the apical one-third of the root and 37.6% of the palatal surfaces. There was mild root resorption in 55%, moderate in 10% and severe in 35%. There was no statistically significant difference between the gender, age, type of impaction, side of impaction, and the number, location, or degree of root resorption. Multiple logistic regression models showed significant association (p = 0.024) between gender, type of impaction, and root resorption. A significant correlation was found between the level and the surface of the root resorption (p = 0.018). Conclusion: In the Saudi population, apical one-third root levels and palatal surfaces were primarily involved in root resorption caused by impacted canines. The females with bilateral canine impaction were more likely affected by root resorption.

Open and closed surgical exposure of palatally displaced canines: a cost-minimization analysis of a multicentre, randomized controlled trial

OBJECTIVE

To evaluate the costs of open and closed surgical exposure and subsequent orthodontic treatment for the correction of palatally displaced canines (PDCs).

TRIAL DESIGN

A multicentre, two-arm parallel group randomized controlled trial.

METHODS

One hundred twenty adolescents between 9 and 16 years of age, from three orthodontic specialist centres, were randomized to one of the two surgical exposure interventions. The randomization was conducted according to a two-arm parallel group 1:1 allocation ratio, using computerized lists with block randomization. In both the surgical techniques, whole mucoperiosteal flaps were raised, and bone covering the PDCs was removed. In the open technique, glass ionomer was built up on the PDC crown - reaching above the mucosa through a hole punched in the flap - to allow the canine to erupt autonomously. After eruption, the canine was orthodontically moved above the mucosa. In the closed technique, an eyelet was bonded onto the PDC, the flap was repositioned and the canine was orthodontically moved beyond the mucosa. The trial ended when the PDC was successfully aligned in the dental arch.Cost analysis was performed including costs for surgery, orthodontic treatment, emergency visits, and material, as well as costs for transports and time spent in connection with every appointment.

BLINDING

Patients and caregivers could not be blinded due to obvious limitations of the clinical setting, while outcome assessors and data analysts were blinded.

RESULTS

A cost-minimization analysis was performed since both exposure groups succeeded equally well in terms of treatment effects. The two different surgical exposures and following orthodontic treatments did not differ significantly in terms of costs.

GENERALIZABILITY AND LIMITATIONS

Costs are estimated in the Swedish setting, which needs to be considered if applying the results in other settings. Calculations of total cost do not include finishing, debonding, retention, and follow-up.

CONCLUSION

There is no significant difference in costs between closed and open surgical exposure with following orthodontic treatments in PDCs.

TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02186548.

Open vs closed surgical exposure of palatally displaced canines: a comparison of clinical and patient-reported outcomes-a multicentre, randomized controlled trial

OBJECTIVES

To compare treatment time, patients' perceptions during orthodontic treatment, dental fear and side effects, between open and closed surgical exposures in patients with palatally displaced canines (PDCs).

TRIAL DESIGN

Multicentre, randomized controlled trial, with random 1:1 allocation of two parallel groups.

MATERIALS AND METHODS

One hundred and twenty patients from three different orthodontic centres were randomized into one of the two intervention arms, open or closed surgical exposure. Both techniques had mucoperiosteal flaps raised and bone removed above the PDCs. In open exposure, tissue was removed above the canine, and glass ionomer - reaching above soft tissue - was built on the crown. The canine was then left to erupt spontaneously, prior to orthodontic alignment. At closed exposure, a chain was bonded to the canine and orthodontic traction was applied under the mucosa until eruption. Orthodontic alignment of the canines was undertaken after eruption into the oral cavity, with fixed appliances in both groups. All participants were treated according to intention to treat (ITT).

BLINDING

Due to the nature of this trial, only outcome assessors could be blinded to the intervention group.

RESULTS

One hundred and seventeen patients completed the trial. All PDCs were successfully aligned. Total treatment time was equal in the two techniques, mean difference -0.1 months (95% CI -3.2 to 2.9, P = 0.93). The closed group experienced more pain and discomfort during the active orthodontic traction. Dental fear, root resorption and periodontal status did not show any clinically significant differences between the groups.

GENERALIZABILITY

Results of this randomized controlled trial (RCT) can be generalized only to a similar population aged 9-16 years, if exclusion criteria are met.

CONCLUSION

The closed exposure group experienced more pain and discomfort mostly during active orthodontic traction. All other studied outcomes were similar between the two exposure groups.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, ID: NCT02186548 and Researchweb.org, ID: 127201.

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.

Adult orthodontic retreatment of severe root resorption by skeletal anchorage: A case report

The presence of root resorption and its correlated factors are concerns that must be considered in orthodontic planning. This case report describes the orthodontic retreatment of a patient with a dental to facial midline discrepancy, a severe apical root resorption, and with maxillary and mandibular incisors presenting accentuated labial tipping and protrusion. The treatment included self-ligating brackets, maxillary unilateral distalization with skeletal anchorage and a mandibular extraction, followed by retraction. The orthodontic planning was based on simple and efficient mechanics and the treatment duration was of 19 months. Based on the acceptable final results it can be assumed that the treatment choices enabled a successful approach, maintaining a stable root condition.

Systematic review versus structured critical analysis

Objective: This analysis discusses common problems with systematic reviews (SRs) and presents a novel solution, the structured critical analysis (SCA) that can be incorporated into a SR or used as an alternative literature review design.Methods: A cross-sectional survey of current SRs related to interdisciplinary restorative dentistry was obtained by evaluating 100 current SRs for their self-reported methodological quality and its effect on scientific validity.Results: The preferred reporting items for systematic reviews and meta-analyses protocol (PRISMA) was used in 99/100 SRs, but only 8/100 reported a low risk of bias. High statistical heterogeneity precluding meta-analysis was found in 44/100 SRs. Only 94 paragraphs/100 SRs provided critical analysis.Discussion: Significant problems were found with current SRs that can compromise their reliability as the premier level of evidence for clinical science research. The reader must be aware of these deficiencies to correctly interpret the SR and cannot rely on the format alone.