The treatment timing of labial inversely impacted maxillary central incisors: A prospective study

Effectiveness and side effects of orthodontic traction of impacted maxillary incisors in a labially inverted position: A systematic review

INTRODUCTION

Treatment of impacted upper incisors in a labially inverted position is challenging for orthodontists, and its prognosis has not been established in the literature. Thus, this systematic review aimed to determine the effectiveness and side effects of orthodontic traction of impacted maxillary incisors in a labially inverted position.

METHODS

A comprehensive search was conducted in multiple databases, including MEDLINE (via PubMed), Scopus, Embase, Science Direct, and LILACS, up to June 30, 2024. Initially, 1640 articles were identified, and after applying specific selection criteria, 11 articles were selected for full-text evaluation. Following the review, only six studies were deemed relevant, comprising one before-and-after study, two longitudinal retrospective studies, and three cross-sectional studies. Newcastle-Ottawa and Risk of Bias (ROB-2) tools were used to assess the risk of bias in the selected studies.

RESULTS

The average duration of traction for maxillary labially inverted impacted central incisors ranged from 8.60±1.26months to 18±6.0months, with all cases being successfully treated. Following traction, the clinical crown height of the incisors was significantly higher compared to the control group (P<0.01). Similarly, the root length of the impacted incisors after traction was shorter in the impaction group (approximately 2mm) compared to the control group. Likewise, the thickness of the alveolar bone varied among different studies. Some authors noted that the treatment group had a smaller thickness (about 0.5mm) compared to the control group (P<0.05), while other authors found similar thickness after treatment.

CONCLUSIONS

Although there are few reported studies with a low risk of bias, it is clear that it is possible to successfully treat labially inverted impacted maxillary central incisors with apparently few side effects. Following traction, the clinical crown height of these incisors increased, while the root length was shorter than their normally erupted contralateral teeth.

Effect of force direction and impaction angulation during dilaceration impacted central incisor traction: a finite element analysis

BACKGROUND

The effects of traction forces at different angles on impacted central incisors(ICI)with varying inverted angles (IA) may be different. The objective of this study was to analyze the biomechanical effects of different force directions (FD) on developmentally inverted ICI with multi-angle variations and to offer insights and guidance for the treatment of inverted ICI.

METHODS

Three-dimensional finite element method was employed to simulate clinical scenarios of inverted ICI traction. As such, 0.2 N of force (direction: antero-superior angles of 90°, 100°, 110°, 120°, and 130° relative to the long axis of the inverted ICI crown) was applied to the inverted ICI with inverse angles (IA) of 40°, 30°, 20°, 10° and 0°. Inverted ICI apical displacement and Von Mises stress on periodontal ligament (PDL) and alveolar bone were compared.

RESULTS

IA and FD showed minimal influence on the stress distribution in the PDL, as higher stresses were concentrated in the apical region. The higher stresses in the alveolar bone are focused on the cervical and apical regions of the tooth. In particular, IA exerts a more significant impact on stress distribution in the alveolar bone than FD. The influence of IA on the apical displacement of inverted ICI is larger than that of FD.

CONCLUSIONS

To promote the health of the root and periodontal tissues, it is recommended to use an angle of 100°-110° relative to the long axis of the ICI crown when dealing with a large IA (> 20°) developmentally inverted ICI. Conversely, an angle of 110°-120° can be used.

Factors affecting local alveolar bone thickness in unilateral maxillary canine-lateral incisor transposition

INTRODUCTION

This study aimed to use 3-dimensional data to investigate the factors affecting local alveolar bone thickness in unilateral maxillary canine-lateral incisor transposition.

METHODS

Pretreatment cone-beam computed tomography data of 34 patients with unilateral maxillary canine-lateral transposition were imported into Dolphin Imaging software (version 11.8; Dolphin Imaging and Management Solutions, Chatsworth, Calif) for 3-dimensional reconstruction. The age, gender, and type of transposition at the beginning of treatment were recorded. The thickness and height of the transposed canine, the labiopalatal and distomedial distance from the transposed canine to the apex of the lateral incisor, the inclination of the transposed lateral incisor, the apical height of the lateral incisor, and the alveolar bone thickness in the apical plane were measured. Multiple linear regression analyses were applied to investigate the factors affecting alveolar bone thickness in the apical plane of the transposed lateral incisor. Two sample t test were applied to assess the difference of alveolar bone thickness in patients of different ages.

RESULTS

The 10 boys and 24 girls had a mean age of 12.26 ± 2.34 years. In all 34 participants, the apical alveolar bone thickness of transposed lateral incisors was significantly higher than that of the unaffected side (P <0.05). Based on multiple regression analyses, factors associated with a wider alveolar bone thickness were as follows: age (β = -0.237; P = 0.008), the labiopalatal distance from the transposed canine to the apex of the lateral incisor (β = 0.675; P <0.001), and the inclination of the transposed lateral incisor (β = 0.048; P = 0.032). Patients aged <11 years had significantly thicker alveolar bone than that of patients aged >11 years (P <0.05).

CONCLUSIONS

Patients with younger age, greater lateral incisor inclination, and greater labiopalatal distance between canine and lateral incisor had more alveolar bone thickness. Early treatment permits tooth movement within the thicker alveolar bone.

Appropriate timing of treatment contributes to better root development of impacted anterior teeth in children

INTRODUCTION

This study investigated the effects of different timings of orthodontic treatment on the root development of impacted anterior teeth in children.

METHODS

The cone-beam computed tomography (CBCT) data of 45 children with impacted anterior teeth were divided into unformed root (UR) group or basically formed root (BFR) group to evaluate root length (RL) and root growth length (RGL) of impacted teeth and contralateral nonimpacted teeth pretreatment and posttreatment. In addition, 22 patients with impacted dilaceration were selected to assess the effects of the crown-root angle and root development stage on RL and RGL. The Student t test, Wilcoxon test, analysis of variance, and multiple linear regression analysis were used for statistical evaluations.

RESULTS

The RL of treated impacted teeth pretreatment and posttreatment was significantly shorter than contralateral nonimpacted teeth values (P <0.05). Posttreatment, the RL and RGL of impacted teeth of the UR group were significantly greater than those of the BFR group (P <0.05). The RGL of the dilacerated root in the UR group was considerably higher than in the BFR group (P <0.05). The larger crown-root angle group had a longer posttreatment RL (P <0.05). Multiple linear regression analysis revealed that the Nolla stage of impacted teeth and RL of contralateral teeth pretreatment significantly influenced the RL of impacted teeth posttreatment.

CONCLUSIONS

Prompt orthodontic treatment is necessary for children with impacted anterior teeth to release the impacted state and achieve better root development. The root length of a dilacerated tooth continued to develop under treatment, but the crown-root angle partly constrained it.

Effect of dental follicles in minimally invasive open-eruption technique of labially impacted maxillary central incisors

OBJECTIVES

To summarize the open-eruption technique of impacted anterior maxillary teeth, this study reports a technically improved operation on surgical exposure based on dental follicles and evaluates post-treatment periodontal health considering the effect of dental follicles.

METHODS

Patients who underwent open-eruption technique with unilateral labially impacted maxillary central incisors were selected. The impacted teeth were assigned to the experimental group, and the contralateral unimpacted maxillary central incisors were assigned to the control group. In the surgical exposure, the new technique makes use of dental follicles to manage the soft tissue, so as to preserve soft tissue for better aesthetic results and healthier periodontal tissue. Tooth length, root length, alveolar bone loss, and alveolar bone thickness were recorded after the therapy.

RESULTS

A total of 17 patients with unilateral maxillary central incisor impaction were successfully treated. The tooth length and root length of the two groups showed a statistically significant difference between the impacted and homonym teeth, with a shorter length in the impacted tooth (P<0.05). More labial alveolar bone loss was found in the experimental group compared with that in the control group (P<0.05). The outcomes of the cementoenamel junction width, pa- latal alveolar bone loss, and alveolar bone thickness did not indicate statistical significance between the experimental and control groups (P>0.05).

CONCLUSIONS

In the surgical exposure, the new technique uses dental follicles to manage the soft tissue and preserve it for better aesthetic results and healthier periodontal tissues.

The evaluation of lateral incisor adjacent to treated labial inversely impacted maxillary central incisor: A retrospective follow-up study

INTRODUCTION

This retrospective study aimed to evaluate the further development of the lateral incisor and its associated periodontium adjacent to the treated labial inversely impacted maxillary central incisor.

METHODS

We enrolled 23 participants (average age, 8.24 ± 1.43 years) undergoing a mean follow-up period of 31.10 ± 13.05 months. Each participant had an unimpacted lateral incisor and a successfully treated unilateral labial inversely impacted maxillary central incisor. The contralateral lateral incisors served as controls. Cone-beam computed tomography data were available for treatment completion and follow-up stages. The variables (including root length, dental age, root canal width, root-crown angulation, and alveolar bone loss and thickness) were evaluated with Dolphin Imaging software (version 11.95; Dolphin Imaging and Management Solutions, Chatsworth, Calif).

RESULTS

At the follow-up stage, the lateral incisors in the impacted side had significantly longer root lengths, smaller root canal widths, and thinner labial bone widths at the apex than at the posttreatment stage (P <0.001, P = 0.036, and P = 0.001, respectively). A significant lateral incisor root length reduction was noted when comparing the impacted and contralateral sides, although no variation was observed in root canal width. Similarly, crown-root angulation of the lateral incisor on the impacted side was significantly larger than that of the contralateral lateral incisor. The lateral incisor on the impacted side also had thicker labial and thinner lingual bone widths at the apex than the contralateral lateral incisor.

CONCLUSIONS

The lateral incisor adjacent to the successfully treated labial inversely impacted maxillary central incisor showed continuous growth during follow-up stages, exhibiting a similar morphology and alveolar bone quality but shorter root length, larger root angulation, and thinner lingual bone width at the apex than those of the contralateral lateral incisors.

Effects of short-term orthodontic force application on the root at different developmental stages in rat maxillary molars

INTRODUCTION

The suitable timing and duration of orthodontic force to be applied to teeth with developing roots are unclear. We investigated the effects of short-term orthodontic force application on the roots at different root developmental stages in rats to predict the optimal timing for orthodontic treatment of teeth with developing roots.

METHODS

Light orthodontic force was applied on the maxillary first molars of rats from postnatal day (PN) 21 or PN28 for 3 days. After that, the force was released, and the roots were evaluated on PN35 to determine the root length, apical morphology, and cell proliferation of the maxillary first mesial roots using microcomputed tomography and histologic evaluation.

RESULTS

When a light orthodontic force was applied from PN21, the root length did not differ from that in age-matched controls. In addition, after the force was released, the roots attained the normal root-completing length and had a well-formed root apical morphology at PN35. Conversely, when the force was applied from PN28, the roots showed apical abnormalities characterized by deformed dentin and disorganized arrangement of odontoblasts, reduced apical cell proliferation, and significantly shorter length than those in the age-matched controls at PN31. The shortened root and disturbed apical integrity could not be rescued by releasing the orthodontic force at PN35.

CONCLUSIONS

Short-term orthodontic force at the late and slow root developmental stage results in a shortened root and a defect in the root apex with reduced cell proliferation. Our findings support that orthodontic force for a limited duration during the active and rapid root developmental stage is more favorable than during the late and slow stage.

Post-trauma complex orthodontic approach: the impact of psychological issues of bullying on treatment decision

Objective:

This article aims to discuss the multidisciplinary approach required in the treatment of cases of impaction and ankylosis of permanent teeth, associated with a history of trauma, considering the psychological state of the child and family when faced with a traumatic case of bullying, by reporting the complex treatment of a central incisor needing to be orthodontically moved across the midline.

Conclusion:

This clinical case was a major challenge, which included complex multidisciplinary procedures. Results and stability after 26 months of retention indicated successful orthodontic space closure of two maxillary teeth, without the use of implants or prostheses, in an adolescent patient who had a history of dental trauma, alveolar bone loss, and an uncertain initial prognosis.

The position and morphology characteristics of multiple impacted anterior teeth in the unilateral maxillary area: A retrospective study based on cone-beam computed tomography

INTRODUCTION

This study investigated the position and morphologic characteristics of multiple impacted anterior teeth in the unilateral maxillary area.

METHODS

Cone-beam computed tomography images of 21 patients (11 males and 10 females; median age 9.42 years [9.08-11.29]) with multiple teeth impacted were collected and imported into Dolphin Imaging software (Dolphin Imaging and Management Solutions, Chatsworth, Calif). The vertical height, crown orientation, twist direction, and root curvature of each impacted tooth were described. The crown length, root length, and root canal width of impacted and homonym teeth were measured.

RESULTS

The positions of the impacted lateral incisors are lower than that of the other 2 anterior teeth. Most crowns of impacted central incisors are positioned distally, labial surfaces in mesial torsion, with most roots, bent toward the distal and labial. Crowns of impacted lateral incisors are positioned mesiolabially, with labial surfaces mostly in distal torsion, and most roots bent toward the mesial and labial. Crowns of impacted canines are mostly positioned mesiolabially, with labial surfaces in mesial torsion. The crowns and roots of the impacted central and lateral incisors were shorter than those of the homonym (P <0.05); however, the difference in crown length is clinically negligible, and there was no difference in root canal widths. There was no difference in the comparison of parameters for the canine group.

CONCLUSIONS

There are certain rules in the vertical height, crown orientation, twist direction, and root curvature of multiple impacted anterior teeth in the unilateral maxillary area. Root development of impacted central and lateral incisors was restricted.

Efficacy of three surgical methods for gingivectomy of permanent anterior teeth with delayed tooth eruption in children

OBJECTIVE

To compare the efficacy of three surgically assisted permanent anterior tooth eruption methods (laser surgery, electrosurgery and routine surgery) in children.

METHOD

Sixty-three orthodontic children with retarded permanent anterior tooth were selected and according to the random number table divided into three groups: laser surgery group (group A), electrosurgery group (group B) and routine surgery group (group C). The total operative time (min), the duration of pain after gingival excision (d), Visual Analogue Scale (VAS) pain intensity scores (0-10 cm), and gingival healing time (d) were all recorded. Six months after treatment, periodontal indexes of the three groups, including gingival indexes (GI), plaque indexes (PLI), probing depth (PD) were checked by the same periodontist and recorded.

RESULTS

Surgical records showed that compared with group C, there were statistically significant differences in operative time, pain duration, pain intensity and healing time in group A and B (P < 0.05). There was no significant difference in these four results between group A and group B. Periodontal examination indicators 6 months after surgery showed no statistical differences in GI, PLI and PD among group A, B and C. Oral clinical examination found that the three groups of patients with different treatment, dental eruption was normal.

CONCLUSION

All the three treatments can effectively solve the problem of delayed eruption of permanent anterior teeth in children. Particularly, laser surgery and high-frequency electrosurgery have good efficacy, little pain and high operability, which can be considered as a better method to aid teeth eruption.

Periodontal status of maxillary central incisors after orthodontic traction: a longitudinal follow-up

BACKGROUND

The aim of this study was to evaluate the clinical and radiographic periodontal status of impacted permanent maxillary central incisors (Mx.1) after a long term of orthodontic traction.

METHODOLOGY

This split-mouth study evaluated a sample of 11 patients (five females, six males) treated with Mx.1 unilateral traction one to 28 years after the removal of orthodontic appliances. The traction Group (TG) consisted of 11 Mx.1 and the Comparison Group (CG) comprised 11 spontaneously erupted contralateral Mx.1. High-resolution CBCT exams of central incisors were performed using Accuitomo (J. Morita, Kyoto, Japan). Cross-section imagens passing through the center of maxillary central incisors were used to measure buccal and lingual alveolar bone level. Presence of fenestration, root dilacerations, root coverage, and position of the root apex were also assessed in the same images. Clinical parameters included periodontal probing depth, attachment level, gingival bleeding index, plaque index, degree of gingival recession, amount of gingival mucosa, and evaluation of interproximal papilla and black triangle. Digital model analysis included an assessment of clinical crown height and width. Intergroup comparisons were performed using paired t-, McNemar's, and Wilcoxon tests (p<0.05).

RESULTS

Compared to CG, we found a significantly thinner labial bone plate thickness in TG at the middle (p=0.000) and apical (p=0.009) root level. We also observed an apical displaced labial bone crest level in TG (p=0.000). The Traction Group showed a greater frequency of root dilacerations and gingival recessions, a decreased amount of keratinized mucosa, and a decreased clinical attachment level at the labial aspect compared to contralateral teeth.

CONCLUSIONS

A decreased thickness and height of labial alveolar bone and gingival recessions were found in maxillary central incisors 15 years after orthodontic traction. Though incisor traction might cause some periodontal impact, differences are acceptable under a clinical point of view considering the cost-benefit ratio.

The Morphology of Impacted Maxillary Central Incisors: A Systematic Review

Background and Objectives: The knowledge of the morphology of impacted maxillary central incisors may lead to more effective treatment. Therefore, this systematic review aimed to evaluate the morphology of impacted maxillary central incisors and compare them with contralateral teeth. Material and methods: This systematic review adhered to the PRISMA statement. The literature search was carried out using PubMed (Medline database), Cochrane Library, ProQuest, Web of Science and Science Direct electronic databases with no publication date restrictions up to July 2021. Data assessing the morphology of unilaterally impacted maxillary central incisors (ICI) evaluated with CBCT were extracted, and the quality of the studies was evaluated. Crown length, root length, and root dilaceration of impacted maxillary central incisors were compared with contralateral unimpacted teeth. Results: The initial database search identified a total number of 287 studies. After applying the selection criteria, 21 articles were selected for a full-text analysis, and four retrospective studies involving 205 patients were included in the systematic review. According to the Newcastle-Ottawa Scale (NOS), two of included articles were graded as “Good” and the remaining two as “Fair” quality. The results showed no difference between impacted teeth and their contralateral crowns, or a minor decrease in ICI crown length (from 0.15 to 0.56 mm). The root lengths of impacted maxillary central incisors were considerably shorter than contralateral incisors (from 2.13 to 3.22 mm) and, as dental age increased, root growth decreased and the incidence of root dilaceration was more frequent. Conclusions: The root lengths of impacted maxillary central incisors were considerably shorter compared to the contralateral incisors. Root dilacerations frequency and severity increased as dental age increased.

An analysis of clinical and imaging features of unilateral impacted maxillary central incisors: A cross-sectional study

INTRODUCTION

This cross-sectional study sought to assess clinical features and 3-dimensional distribution of unilateral impacted maxillary central incisors and identify factors associated with the root morphology.

METHODS

Cone-beam computed tomography (CBCT) images from 94 subjects exhibiting unilateral impacted maxillary incisors were selected and evaluated. Original CBCT data were reconstructed using Mimics software (version 17.0; Materialise, Belgium). Clinical features and 3-dimensional distribution of impacted maxillary central incisors and factors associated with the root morphology were observed and analyzed by 2 orthodontists.

RESULTS

This patient cohort included 52 male patients and 42 female patients. Thirty-three incisors (35.11%) with dilacerated roots, 17 incisors (18.09%) with retained deciduous teeth, 15 incisors (15.96%) with supernumerary teeth, and 15 incisors (15.96%) with a history of trauma were identified in the study. Of the 94 impacted incisors, the most common were labially impacted (n = 65; 69.15%), followed by vertically impacted (n = 17; 18.09%) and palatally impacted (n = 12; 12.77%). Chi-square tests revealed that differences in subjects with supernumerary teeth, buccolingual position, sagittal position, and axial position in the upright and dilacerated root groups were statistically significant (P <0.05). Logistic regression analysis indicated that the incidence of dilacerations was higher in the inverted position than in the inclined position and horizontal position (P <0.05).

CONCLUSIONS

Labially impacted maxillary incisors were more common than vertically or palatally incisors. Dilaceration was most commonly observed in patients with inverted incisors. In clinical practice, CBCT is a valuable tool for diagnosing impacted maxillary central incisors and for making appropriate treatment plans for patients.

Post-Treatment Status of Impacted Maxillary Central Incisors following Surgical-Orthodontic Treatment: A Systematic Review

Background and Objectives: The aim of this systematic review was to summarize currently available data of published articles that have investigated the post-treatment status of impacted maxillary central incisors (ICI) treated by the surgical-orthodontic approach. Materials and Methods: MEDLINE, Scopus, Cochrane Oral Health Group’s Trials Register, and ScienceDirect electronic databases were systematically searched with no publication date restrictions up to January 2021. Data assessing the status of ICI after combined surgical-orthodontic treatment and forced eruption duration were extracted, and the quality of the studies was evaluated. Results: In total, 7074 studies were identified, of which 42 articles were assessed for eligibility through full-text evaluation. Seven included studies (five retrospective studies, one randomized clinical trial, and one prospective clinical trial) met the inclusion criteria, representing 211 patients with unilaterally impacted maxillary incisors. The risk of bias ranged from moderate to high. The results show that the root length of immature ICIs increased significantly but remained shorter than that of homonym teeth at post-treatment. Periodontal parameters of treated ICIs were in a clinically acceptable range. Measurements of the alveolar bone showed a reduction of bone thickness and support. The average forced eruption duration ranged from 8.0 ± 4.5 to 14.41 ± 4.03 months. Conclusions: Based on existing evidence, it is reasonable to conclude that the surgical-orthodontic treatment affected the post-treatment status of ICI; however, the current literature is insufficient to draw concrete conclusions. Further well-conducted multi-center randomized studies with a large sample are needed to confirm this statement.

Cone-beam CT in paediatric dentistry: DIMITRA project position statement

DIMITRA (dentomaxillofacial paediatric imaging: an investigation towards low-dose radiation induced risks) is a European multicenter and multidisciplinary project focused on optimizing cone-beam CT exposures for children and adolescents. With increasing use of cone-beam CT for dentomaxillofacial diagnostics, concern arises regarding radiation risks associated with this imaging modality, especially for children. Research evidence concerning cone-beam CT indications in children remains limited, while reports mention inconsistent recommendations for dose reduction. Furthermore, there is no paper using the combined and integrated information on the required indication-oriented image quality and the related patient dose levels. In this paper, therefore, the authors initiate an integrated approach based on current evidence regarding image quality and dose, together with the expertise of DIMITRA's members searching for a state of the art. The aim of this DIMITRA position statement is to provide indication-oriented and patient-specific recommendations regarding the main cone-beam CT applications in the pediatric field. The authors will review this position statement document when results regarding multidisciplinary approaches evolve, in a period of 5 years or earlier.