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1.
Medicina (Kaunas) ; 56(9)2020 Aug 20.
Article in English | MEDLINE | ID: mdl-32825215

ABSTRACT

Background and Objectives: There is still considerable controversy regarding the possibility of submitting replanted teeth to orthodontic movement (OM). The purpose of the present study was to evaluate the tissue response after orthodontic movement on replanted teeth. Materials and Methods: Sixty Wistar rats were randomly assigned to four groups (n = 15): G1, replantation without OM after 30 days; G2, replantation with OM after 30 days; G3, replantation without OM after 60 days, and G4, replantation with OM after 60 days. The maxillary left central incisors were extracted and the teeth were stored in milk media. After 30 min, the teeth were replanted and fixed with non-rigid immobilization. All specimens were observed after 30 and 60 days of replantation and then subdivided into two subgroups (with OM or without OM). The animals were euthanized after seven days of the OM started, and the maxillary bone blocks were processed for histological evaluation. Results: The histological results showed periodontal ligament repair in both periods studied without OM; however, ankylosis and root resorption was seen in all orthodontically moved teeth. Conclusions: The orthodontic movement did not favor tissue response in all replanted teeth, regardless of the experimental periods.


Subject(s)
Incisor/pathology , Incisor/surgery , Periodontal Ligament/pathology , Root Resorption/pathology , Tooth Movement Techniques/adverse effects , Tooth Replantation , Animals , Incisor/physiopathology , Models, Animal , Photomicrography , Postoperative Complications/pathology , Random Allocation , Rats , Rats, Wistar , Root Resorption/etiology , Tooth Avulsion/surgery , Tooth Root/pathology
2.
Sci Rep ; 10(1): 2841, 2020 02 18.
Article in English | MEDLINE | ID: mdl-32071357

ABSTRACT

This retrospective clinical study investigated the survival probability of avulsed and replanted permanent teeth in relation to functional healing, replacement and inflammatory resorption. The explorative data analysis included data from 36 patients and 49 replanted permanent teeth with a minimum observation time of 60 days; the patients were generally treated according to the current guidelines of the International Association of Dental Traumatology at the university hospital in Munich, Germany, between 2004 and 2017. The mean observation period was 3.5 years. Functional healing was observed in 26.5% (N = 13/49) of the included avulsion cases. In comparison, replacement resorption affected 51.0% (N = 25/49) of the replanted teeth, of which 24.0% (N = 6/25) were lost over the course of years (mean, 6.1 years). In contrast, inflammatory resorption resulted in the early loss of all replanted teeth (mean, 1.7 years) and affected 22.5% (N = 11/49) of all the monitored teeth. Therefore, it can be concluded that tooth avulsion remains a severe dental injury with an unpredictable prognosis. This topic demands further fundamental research aiming to maintain and/or regenerate the periodontal ligament after tooth avulsion, particularly in association with non-physiological tooth rescue.


Subject(s)
Dentition, Permanent , Tooth Avulsion/physiopathology , Tooth Replantation/methods , Wound Healing/physiology , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Germany , Humans , Incisor/growth & development , Incisor/physiopathology , Male , Middle Aged , Periodontal Ligament/growth & development , Periodontal Ligament/physiopathology , Root Canal Therapy , Time Factors , Young Adult
3.
PLoS One ; 14(4): e0215370, 2019.
Article in English | MEDLINE | ID: mdl-30978248

ABSTRACT

Alterations in the structure and mechanical properties of teeth in adult Wistar rats exposed to cadmium were investigated. Analyses were conducted on two sets of incisors from female and male specimens, that were intoxicated with cadmium (n = 12) or belonged to the control (n = 12). The cadmium group was administered with CdCl2 dissolved in drinking water with a dose of 4mg/kgbw for 10 weeks. The oral intake of cadmium by adult rats led to the range of structural changes in enamel morphology and its mechanical features. A significant increase of cadmium levels in the teeth in comparison to the control, a slight shift in the colour and reduction of pigmented enamel length, higher surface irregularity, a decrease of hydroxyapatite crystals size in the c-axis and simultaneous increase in pigmented enamel hardness were observed. The extent of these changes was sex-dependent and was more pronounced in males.


Subject(s)
Cadmium/toxicity , Incisor/drug effects , Animals , Biomechanical Phenomena , Cadmium/administration & dosage , Cadmium/pharmacokinetics , Crystallization , Dental Enamel/drug effects , Dental Enamel/pathology , Dental Enamel/physiopathology , Durapatite/chemistry , Durapatite/metabolism , Female , Hardness/drug effects , Incisor/pathology , Incisor/physiopathology , Male , Microscopy, Atomic Force , Microscopy, Electron, Scanning , Minerals/metabolism , Rats , Rats, Wistar , X-Ray Diffraction
4.
Niger J Clin Pract ; 22(2): 276-280, 2019 Feb.
Article in English | MEDLINE | ID: mdl-30729955

ABSTRACT

Ectopic eruption originates from the malpositioning of a tooth bud ending in the eruption of the tooth in an improper direction. This anomaly is a consequence of ectopic development of the tooth germ. This condition gives rise to significant aesthetic and occlusal issues in the early mixed dentition stage. The most frequently influenced teeth are the maxillary first molars, accompanied by the maxillary cuspids. Ectopic eruption is seldom seen and might derive from traumatic injury. In some cases, hyperplastic and fibrotic gingival tissue may lead to ectopic eruption of a permanent incisor. Managing ectopically erupting teeth generally rests on several reasons including extraction of supernumerary tooth, removal of cyst and excision of hyperplastic tissue and subsequent to orthodontic movement of tooth if necessary. In this case, the use of Er, Cr: YSGG lasers for the correction of hyperplastic soft tissues involving ectopically erupting permanent incisors are depicted considering two cases.


Subject(s)
Incisor/pathology , Incisor/physiopathology , Lasers , Tooth Eruption, Ectopic/therapy , Tooth Eruption , Tooth, Supernumerary/surgery , Child , Cuspid , Dentition, Mixed , Female , Gingiva , Humans , Male , Molar , Tooth, Supernumerary/pathology , Treatment Outcome
5.
Cranio ; 37(1): 12-19, 2019 Jan.
Article in English | MEDLINE | ID: mdl-28868987

ABSTRACT

OBJECTIVE: The null hypothesis was that mandibular amplitude, velocity, and variability during gum chewing are not altered in subjects with temporomandibular joint (TMJ) internal derangements (ID). METHODS: Thirty symptomatic subjects with confirmed ID consented to chew gum on their left and right sides while being tracked by an incisor-point jaw tracker. A gender and age matched control group (p > 0.67) volunteered to be likewise recorded. Student's t-test compared the ID group's mean values to the control group. RESULTS: The control group opened wider (p < 0.05) and chewed faster (p < 0.05) than the ID group. The mean cycle time of the ID group (0.929 s) was longer than the control group (0.751 s; p < 0.05) and more variable (p < 0.05). DISCUSSION: The ID group exhibited reduced amplitude and velocity but increased variability during chewing. The null hypothesis was rejected. Further study of adaptation to ID by patients should be pursued.


Subject(s)
Mastication , Temporomandibular Joint Disorders/physiopathology , Temporomandibular Joint/physiopathology , Adult , Chewing Gum , Female , Humans , Incisor/physiopathology , Magnetics , Male , Mandible , Middle Aged , Movement , Young Adult
6.
Am J Orthod Dentofacial Orthop ; 155(1): 28-39, 2019 Jan.
Article in English | MEDLINE | ID: mdl-30591160

ABSTRACT

INTRODUCTION: The orthodontic traction of impacted canines is a procedure of variable complexity. The objective of this study was to determine the influence of this complexity on the root resorption (RR) of adjacent incisors, using cone-beam computed tomography. METHODS: This longitudinal retrospective study included 45 patients (19 female, 11 male; ages, 18.16 ± 7.3 years) with maxillary impacted canines, classified into 2 groups according to the level of orthodontic traction complexity: low complexity group (n = 20) and high complexity group (n = 25). The amounts of RR of 45 maxillary central and 45 lateral incisors were evaluated before and after treatment. Complexity was defined considering impaction sector, eruption inclination angle, and canine position (palatal, buccal, or bicortical). Three orthodontists measured RR in each maxillary incisor. Independent t tests or Mann-Whitney U tests were used to compare resorption between groups depending on the normality of the data. A multiple linear regression was calculated to evaluate the influence of all variables on RR (α = 0.05). RESULTS: RR of maxillary incisors in the sagittal, coronal, and axial sections showed no significant differences between groups (P > 0.05). Independently of the groups, RR ranged approximately from 1 to 1.5 mm and from 3 to 4 mm2. RR was less than 2 mm2 in the axial sections. Multiple linear regression indicated no significant influence of orthodontic treatment complexity on RR. Male patients had more RR, specifically in the maxillary central incisors than female patients (P < 0.05). CONCLUSIONS: The complexity of orthodontic traction of impacted maxillary canines is not a risk factor for greater RR of maxillary incisors close to the impaction area.


Subject(s)
Incisor/physiopathology , Orthodontic Appliances, Fixed , Orthodontics, Corrective/adverse effects , Root Resorption/etiology , Tooth, Impacted/therapy , Adolescent , Child , Cone-Beam Computed Tomography , Female , Humans , Incisor/diagnostic imaging , Linear Models , Longitudinal Studies , Male , Maxilla , Orthodontic Anchorage Procedures/adverse effects , Orthodontic Anchorage Procedures/instrumentation , Retrospective Studies , Risk Factors , Tooth, Impacted/complications , Tooth, Impacted/diagnostic imaging
7.
Stomatologija ; 20(3): 102-108, 2018.
Article in English | MEDLINE | ID: mdl-30531165

ABSTRACT

OBJECTIVE: Canine impaction is a dental anomaly involving intraosseous displacement of the unerupted tooth. This situation is of significant importance causing orthodontic, surgical and interceptive problems. Trauma in the incisor area is a possible cause of the displacement of the tooth bud of the permanent canine resulting in the deviated eruption path. The aim of this article is to present two clinical cases with diagnosis of maxillary canine displacement and impaction in the incisor region after a traumatic injury during childhood, discussing treatment possibilities and outcomes achieved after orthodontic treatment. MATERIALS AND METHODS: In this article ectopic maxillary canines migration in the central incisor area after a traumatic injury to the anterior upper teeth are described. The path of eruption of the canine can cause severe central incisor root resorption. Treatment strategy established for the case reports described involves orthodontic space opening, extraction of the central incisor, uncovering the impacted canine and orthodontic traction of the tooth in place of central incisor. Modification of crown morphology and color were essential to obtain an aesthetic and function outcome. RESULTS: The patients finished treatment with normal and stable occlusion, an adequate width of attached gingiva and good aesthetic results. CONCLUSION: Authors suggest that might have been a possible connection between the trauma of primary dentition causing the displacement of the tooth bud of permanent canine and the deviated path of eruption. For the growing patients with a combination of dental trauma and ectopic eruption, maxillary canine to replace a central incisor was a viable option, offering excellent aesthetic results without recourse to prosthetic replacement.


Subject(s)
Cuspid , Incisor/physiopathology , Root Resorption/etiology , Tooth Injuries/complications , Tooth Movement Techniques , Tooth, Impacted/complications , Child , Female , Humans , Incisor/diagnostic imaging , Incisor/injuries , Male , Maxilla , Radiography, Panoramic , Root Resorption/diagnostic imaging , Tooth, Impacted/physiopathology , Tooth, Impacted/therapy
8.
Am J Orthod Dentofacial Orthop ; 154(5): 645-656, 2018 Nov.
Article in English | MEDLINE | ID: mdl-30384935

ABSTRACT

INTRODUCTION: The aim of this study was to compare the root resorption (RR) of maxillary incisors after traction of unilateral vs bilateral impacted canines with reinforced anchorage. METHODS: This retrospective longitudinal study included 60 cone-beam computed tomography scans of patients with maxillary impacted canines: 30 scans taken before and 30 taken after orthodontic traction with nickel-titanium coil springs. Two groups were formed according to the impaction condition: 15 with unilateral maxillary impacted canines and 15 with bilateral maxillary impacted canines. Three trained orthodontists made the measurements. Demographic variables, occlusal characteristics, skeletal class, and measurements related to canine impaction were collected from the clinical history, dental models, and radiographs of each patient. RR (mm and mm2) for each maxillary incisor was measured in 3 dimensions. Independent t or Mann-Whitney U tests were used, depending on data normality. Multiple linear regression analyses were used to evaluate the influence of all variables (predictors) on RR (α = 0.05). RESULTS: RR did not show significant differences between groups in any section (P > 0.05). No subject had RR greater than 2 mm or 5 mm2. The specific influence of some predictor variables varied depending on the type of maxillary incisor. CONCLUSIONS: RR of maxillary incisors after traction of unilateral vs bilateral impacted canines with reinforced anchorage was similar and is not a risk to the integrity of the maxillary incisor root.


Subject(s)
Cuspid , Incisor/physiopathology , Orthodontic Anchorage Procedures/methods , Root Resorption , Tooth, Impacted/physiopathology , Tooth, Impacted/therapy , Cone-Beam Computed Tomography , Cuspid/diagnostic imaging , Female , Humans , Imaging, Three-Dimensional , Longitudinal Studies , Male , Maxilla , Nickel , Orthodontic Anchorage Procedures/instrumentation , Retrospective Studies , Risk Factors , Titanium , Tooth, Impacted/diagnostic imaging , Traction , Young Adult
9.
Curr Med Sci ; 38(5): 914-919, 2018 Oct.
Article in English | MEDLINE | ID: mdl-30341529

ABSTRACT

This study aims to evaluate the long-term stability of vertical control in hyperdivergent patients treated with temporary anchorage devices. The sample included 20 hyperdivergent patients without anterior open bite. The temporary anchorage devices were used to intrude the upper incisor and molars for vertical control. Lateral cephalograms were established prior to treatment, immediately after treatment, and during retention. The upper molars and incisors were intruded by 1.33 mm and 1.41 mm after treatment (P<0.05). U6-PP increased by 0.11 mm and 0.23 mm during the first and second stages of retention (P>0.05). U1-PP was found to possess a significant extrusion of 1.2 mm during the first stage (P<0.05), which increased by 0.68 mm during the second stage (P>0.05). The mandibular plane angle (MP-SN) decreased by 2.58 degrees following treatment, and underwent a relapse of 0.51 degree and 0.42 degree during the first and second stages of retention respectively (P>0.05). No significant soft tissue changes occurred, with the exception of increased upper lip length during the second stage (P<0.05). Maxillary anterior and posterior intrusions, counter clockwise rotation of the mandibular plane, and improved profiles can be successfully achieved following treatment with vertical control. During the first stage of retention (less than three years), intruded molars and incisors both exhibited some extrusion, and molars had better long-term stability than incisors. During the second stage of retention (three to six years), the therapeutic effects appeared stable, with the exception of some increase in upper lip length. Rotated mandibular plane remained stable during the entire retention period.


Subject(s)
Denture Retention/methods , Open Bite/therapy , Orthodontic Anchorage Procedures/methods , Cephalometry , Female , Humans , Incisor/physiopathology , Male , Mandible/diagnostic imaging , Mandible/physiopathology , Maxilla/diagnostic imaging , Maxilla/physiopathology , Middle Aged , Molar/physiopathology , Open Bite/diagnostic imaging , Open Bite/physiopathology , Orthodontic Appliance Design/methods , Tooth Movement Techniques/methods
10.
Prog Orthod ; 19(1): 17, 2018 Jun 18.
Article in English | MEDLINE | ID: mdl-29911278

ABSTRACT

BACKGROUND: The present systematic review was carried out to determine the correlation between gingival recession/bone height and incisor inclination in non-growing post-orthodontic patients compared to adult untreated subjects or patients treated with different methodologies. MATERIALS AND METHODS: PubMed, EMBASE, Web of Science, Scopus, Cochrane, and OpenGrey databases were searched without time and language restriction. Search terms included orthodontic, incisor, inclination, angulation, proclination, and gingival. Articles involving human participants and adult subjects receiving orthodontic treatment with fixed appliance, having incisors position, bone height and/or gingival recessions evaluated pre- and post-treatment were included. Two authors independently extracted data using predefined forms. Risk of bias in individual studies was assessed with the Newcastle-Ottawa Scale. RESULTS: Two observational studies were included in the qualitative analysis. The heterogeneity in outcome assessment among the studies did not allow performing a meta-analysis. The two studies, while observing some effects of orthodontic treatment on the development of gingival recession, reported that these effects were not statistically or clinically significant. CONCLUSIONS: There is no strong scientific evidence concluding that proclination of incisors by means of fixed orthodontic appliances can affect periodontal health. Further prospective studies are required to elucidate this statement. PROTOCOL: PROSPERO database registration number CRD42016042369 .


Subject(s)
Gingival Recession/etiology , Incisor/physiopathology , Tooth Movement Techniques/adverse effects , Humans , Mandible
11.
Swiss Dent J ; 128(5): 393-399, 2018 May 14.
Article in French, German | MEDLINE | ID: mdl-29734801

ABSTRACT

In the context of tooth trauma, mostly the maxillary central front teeth are involved, whereby their roots are in some cases still in the developing stage (immature). Depending on the type of trauma, a necrosis of the pulp is the consequence or at least foreseeable. In order to preserve such a tooth, an endodontic therapy is inevitable. The disadvantage of conventional endodontic therapy methods of immature teeth (apexification, apexogenesis) is the root growth stop. Alternatively, the regeneration/revascularisation of the dental pulp (RP) was suggested, that allows a further root growth. The aim of this case report is to present the procedure of a RP-therapy and to suggest a step-by-step manual.


Subject(s)
Dental Pulp Necrosis/surgery , Endodontics/methods , Incisor/injuries , Regenerative Medicine/methods , Tooth Avulsion/surgery , Adolescent , Child , Dental Pulp/blood supply , Dental Pulp/physiopathology , Dental Pulp Necrosis/physiopathology , Follow-Up Studies , Humans , Incisor/physiopathology , Incisor/surgery , Lip/injuries , Lip/surgery , Male , Tooth Avulsion/physiopathology , Tooth Replantation/methods
12.
J Orofac Orthop ; 79(3): 181-190, 2018 May.
Article in English | MEDLINE | ID: mdl-29651519

ABSTRACT

OBJECTIVES: Purpose of the present study was to compare external root resorption (ERR) volumetrically in maxillary incisors induced by orthodontic treatment using self-ligating brackets (Damon Q, DQ) or conventional brackets (Titanium Orthos, TO) with the help of cone-beam computed tomography (CBCT). PATIENTS AND METHODS: A sample of 32 subjects, with Angle Class I malocclusion and anterior crowding of 4-10 mm, was divided randomly into two groups: a DQ group, in which self-ligating DQ brackets with Damon archwires were used; and a TO group, in which conventional TO brackets with large Orthos archwires were applied. The study was conducted using CBCT scans taken before (T1), and near the end (9 months after the initiation of treatment; T2) of the orthodontic treatment. The extent of ERR was determined volumetrically using Mimics software. Changes in root volume were evaluated by repeated-measures analysis of variance as well as by paired and independent t-tests. RESULTS: While significant differences were found between T1 and T2 for root volume in both groups (p < 0.05), there was no difference between the groups regarding the amount (mm3 or relative change) of ERR (p > 0.05). Maxillary central and lateral incisors showed similar volume loss (p > 0.05). Furthermore, the TO group showed a higher prevalence of palatinal and proximal slanted RR compared with the DQ group (p < 0.05). CONCLUSIONS: It is not possible to suggest superiority of one bracket system over the other only considering root resorption pattern or amount. Higher incidence of slanted RR found in patients treated with the TO system warrants further research to identify possible specific causes.


Subject(s)
Malocclusion, Angle Class I/therapy , Orthodontic Brackets/adverse effects , Root Resorption/etiology , Adolescent , Cone-Beam Computed Tomography , Female , Humans , Incisor/physiopathology , Male , Malocclusion, Angle Class I/diagnostic imaging , Malocclusion, Angle Class I/physiopathology , Orthodontic Appliance Design , Tooth Movement Techniques/instrumentation , Tooth Movement Techniques/methods
13.
Biomed Res Int ; 2018: 9341821, 2018.
Article in English | MEDLINE | ID: mdl-30627583

ABSTRACT

OBJECTIVE: The upper incisors torque expression is essential for the orthodontic treatment accuracy. Various orthodontic devices are claimed to have different inclination control capacity. The purpose of this retrospective study was to compare the radiographic buccolingual inclination of upper incisors in patients treated with three different orthodontic techniques. MATERIAL AND METHODS: Conventional brackets (Victory, 3M), self-ligating appliances (Damon Q, Ormco), and aligners (Invisalign, Align Technology) were tested. Cephalometric data of 25 patients with similar skeletal and dental pretreatment parameters were collected for each technique. Position changes of upper central incisors were assessed with radiographic evaluation before and after therapy. Three different parameters were considered: 11∧SnaSnp, 11∧Ocl and I+ TVL. All variables were measured before (T0) and after (T1) treatment and their variation over treatment was assessed. RESULTS: When evaluating angular measurements, 11∧SnaSnp and 11∧Ocl angles showed the highest numeric variation with conventional brackets. Lowest values were reported with aligners. However, the differences among various techniques were not significant for both angles (P>0.05). Also I+ TVL linear value variation did not show significant differences among the different groups tested (P>0.05). CONCLUSION: Conventional multibrackets appliance showed the highest incisal position variations over treatment, but the differences among various groups were not significantly different.


Subject(s)
Incisor , Orthodontic Brackets , Tooth Movement Techniques/methods , Adult , Female , Humans , Incisor/pathology , Incisor/physiopathology , Male
14.
Eur J Orthod ; 40(1): 107-112, 2018 01 23.
Article in English | MEDLINE | ID: mdl-28591765

ABSTRACT

Objective: To analyze whether the decreased bone density due to the manipulation of bone remodeling rate has an influence on the type of the planned tooth movement. Materials and methods: A finite element model of a lower incisor has been developed. The density of the alveolar bone surrounding the tooth has been assumed to simulate the one occurring after corticotomy to increase tooth movement rate. Moment-to-force ratios corresponding to three different types of movements have been simulated; uncontrolled tipping, translation, and root movement. The three tooth movements have been analyzed in both corticotomized and non-corticotomized simulations, and the final effects on the amount and type of tooth movement analyzed. The stress and strain levels in the periodontal ligament have been analyzed too. Results: The amount of tooth movement obtained in case of lower bone density is higher in all types of movement simulations. The centre of rotation of the movement shifts more apically in case of translation, controlled and uncontrolled tipping. In the corticotomy simulations, the compressive stresses in the periodontal ligament decreased while the tensile stresses increased. Conclusion: A decreased bone density influences not only the amount of tooth movement, but also its type. This study suggests that the moment-to-force ratios used in conventional orthodontics should be modified in case of techniques that decrease bone density to enhance tooth movement rate.


Subject(s)
Alveolar Process/surgery , Incisor/physiopathology , Osteotomy/methods , Tooth Movement Techniques/methods , Alveolar Process/physiopathology , Bone Density/physiology , Bone Remodeling/physiology , Finite Element Analysis , Humans , Models, Biological , Periodontal Ligament/physiology , Stress, Mechanical
15.
J Contemp Dent Pract ; 19(12): 1434-1436, 2018 Dec 01.
Article in English | MEDLINE | ID: mdl-30713169

ABSTRACT

AIM: The aim of this study is to discuss a case of an 11-year-old pediatric patient, who was diagnosed with delayed eruption of the permanent maxillary central incisors because of palatally impacted supernumerary teeth. BACKGROUND: The delayed eruption of permanent teeth can be a result of blocking by supernumerary teeth and over-retained primary teeth. Early diagnosis can help in avoiding the complications. The management of such cases depends on the stage of teeth development, teeth position, and space availability. Treatment may combine both surgical and orthodontic interventions. CASE DESCRIPTION: The case was managed by surgically removing the primary retained teeth and supernumerary teeth in two visits then allowing the impacted permanent incisors to erupt without any intervention. CONCLUSION: After 18 months follow-up, the two permanent incisors erupted spontaneously with no orthodontic intervention. CLINICAL SIGNIFICANCE: dentists should be aware of the importance of early diagnosis of supernumerary teeth. The management of such cases should be designed by a multidisciplinary team decision.


Subject(s)
Dentition, Permanent , Incisor/physiopathology , Maxilla , Tooth Eruption , Tooth Extraction , Tooth, Impacted/etiology , Tooth, Supernumerary/complications , Tooth, Supernumerary/surgery , Tooth, Unerupted/etiology , Child , Early Diagnosis , Follow-Up Studies , Humans , Incisor/physiology , Male , Time Factors , Tooth, Impacted/diagnosis , Tooth, Supernumerary/diagnosis , Tooth, Unerupted/physiopathology , Treatment Outcome
16.
Biomed Res Int ; 2017: 2938691, 2017.
Article in English | MEDLINE | ID: mdl-29226129

ABSTRACT

OBJECTIVES: To assess the relationship between dental follicle width and maxillary impacted canines' descriptive and resorptive features with three-dimensional (3D) cone-beam computed tomography (CBCT). METHODS: The study comprised 102 patients with cone-beam computed tomography 3D images and a total of 140 impacted canines. The association between maxillary impacted canine dental follicle width and the variables of gender, impaction side (right and left), localization of impacted canine (buccal, central, and palatal), and resorption of the adjacent laterals was compared. Measurements were analyzed with Student's t-test, Kruskal-Wallis test, and Mann-Whitney U statistical test. RESULTS: According to gender, no statistically significant differences were found in the follicle size of the maxillary impacted canine between males and females (p > 0.05). Widths of the follicles were determined for the right and left impaction sides, and no statistically significant relation was found (p > 0.05). There were statistically significant differences between root resorption degrees of lateral incisors and maxillary impacted canine follicle width (p < 0.05). Statistically significant higher follicle width values were present in degree 2 (mild) resorption than in degree 1 (no) and degree 3 (moderate) resorption samples (p < 0.05). CONCLUSIONS: No significant correlation was found between follicle width and the variables of gender, impaction side, and localization of maxillary impacted canines. Our study could not confirm that increased dental follicle width of the maxillary impacted canines exhibited more resorption risk for the adjacent lateral incisors.


Subject(s)
Dental Sac/physiopathology , Maxilla/physiopathology , Tooth, Impacted/physiopathology , Adolescent , Cone-Beam Computed Tomography/methods , Female , Humans , Image Processing, Computer-Assisted/methods , Imaging, Three-Dimensional/methods , Incisor/physiopathology , Male , Palate/physiopathology , Retrospective Studies , Root Resorption/physiopathology
17.
Adv Clin Exp Med ; 26(5): 829-833, 2017 Aug.
Article in English | MEDLINE | ID: mdl-29068580

ABSTRACT

BACKGROUND: Loading of the compromised periodontium with orthodontic forces produces different results than those achieved in patients with healthy periodontal support. Determining the force value at a level preventing further deterioration of the patient's periodontal status, thus delivering the most precisely individualized "dose" of loading, seems to be crucial for the successful intrusion of teeth with reduced periodontal support. OBJECTIVES: The aim of the study was to determine the range of force values efficiently intruding maxillary incisors without further compromising the initially-impaired periodontal status. Finite element analysis (FEA), allowing estimation of the stress and strain distribution, was the method of choice. MATERIAL AND METHODS: The CT scans of a periodontally-compromised patient were segmented using InVesalius software. A model - based on NURBS surfaces - was adjusted to the CT scans in order to obtain both smooth and natural curvatures of each model segment. All relevant tissues were modeled as separate volumes. The geometric model was discretized in order to create a numerical model for applying Ansys software (v. 15.07) and using APDL. The central incisors were loaded with external intrusive forces, ranging from 0.1 to 0.4 N. RESULTS: The simulation, performed iteratively, showed that even the lowest force value - 0.1 N - causes stress changes in the alveolus and on the root surfaces, with a tendency of stress increasing towards the bottom of the alveolus and root apex. It is also notable that during the application of forces of equal magnitude, the stress/strain distribution was significantly higher around tooth 21, which displayed the highest range of PDL reduction. Application of the same force level created a higher stress-strain response around tooth 21, and the characteristics were less homogenous. CONCLUSIONS: A force value of 0.1 N applied in vivo might produce the most effective tooth intrusion and bone modeling which favors bone defect regeneration.


Subject(s)
Finite Element Analysis , Incisor/physiopathology , Malocclusion/therapy , Maxilla/physiopathology , Orthodontic Appliances , Patient-Specific Modeling , Periodontium/physiopathology , Tooth Movement Techniques/instrumentation , Computer-Aided Design , Dental Prosthesis Design , Humans , Incisor/diagnostic imaging , Malocclusion/diagnostic imaging , Malocclusion/physiopathology , Maxilla/diagnostic imaging , Periodontium/diagnostic imaging , Radiographic Image Interpretation, Computer-Assisted , Radiography, Dental/methods , Stress, Mechanical , Tomography, X-Ray Computed
18.
J Appl Oral Sci ; 25(5): 483-489, 2017.
Article in English | MEDLINE | ID: mdl-29069145

ABSTRACT

OBJECTIVE: To evaluate the effect of bite positions characterizing different splint treatments (anterior repositioning and stabilization splints) on the disc-condyle relation in patients with TMJ disc displacement with reduction (DDwR), using magnetic resonance imaging (MRI). MATERIAL AND METHODS: 37 patients, with a mean age of 18.8±4.3 years (7 male and 30 females) and diagnosed with DDwR based on the RDC/TMD, were recruited. MRI metrical analysis of the spatial changes of the disc/condyle, as well as their relationships, was done in three positions: maximum intercuspation (Position 1), anterior repositioning splint position (Position 2), and stabilization splint position (Position 3). Disc/condyle coordinate measurements and disc condyle angles were determined and compared. RESULTS: In Position 1, the average disc-condyle angle was 53.4° in the 60 joints with DDwR, while it was -13.3° with Position 2 and 30.1° with Position 3. The frequency of successful "disc recapture" with Position 2 was significantly higher (58/60, 96.7%) than Position 3 (20/60, 33.3%). In Positions 2 and 3, the condyle moved forward and downward while the disc moved backward. The movements were, however, more remarkable with Position 2. CONCLUSIONS: Anterior repositioning of the mandible improves the spatial relationship between the disc and condyle in patients with DDwR. In addition to anterior and inferior movement of the condyle, transitory posterior movement of the disc also occurred.


Subject(s)
Joint Dislocations/physiopathology , Joint Dislocations/therapy , Mandibular Condyle/injuries , Occlusal Splints , Temporomandibular Joint Disc/injuries , Adolescent , Adult , Analysis of Variance , Child , Equipment Design , Female , Humans , Incisor/physiopathology , Joint Dislocations/diagnostic imaging , Magnetic Resonance Imaging , Male , Mandibular Condyle/diagnostic imaging , Mandibular Condyle/pathology , Mandibular Condyle/physiopathology , Observer Variation , Reference Values , Reproducibility of Results , Temporomandibular Joint Disc/diagnostic imaging , Temporomandibular Joint Disc/physiopathology , Treatment Outcome , Young Adult
19.
J. appl. oral sci ; 25(5): 483-489, Sept.-Oct. 2017. tab, graf
Article in English | LILACS, BBO - Dentistry | ID: biblio-893650

ABSTRACT

Abstract Objective: To evaluate the effect of bite positions characterizing different splint treatments (anterior repositioning and stabilization splints) on the disc-condyle relation in patients with TMJ disc displacement with reduction (DDwR), using magnetic resonance imaging (MRI). Material and Methods: 37 patients, with a mean age of 18.8±4.3 years (7 male and 30 females) and diagnosed with DDwR based on the RDC/TMD, were recruited. MRI metrical analysis of the spatial changes of the disc/condyle, as well as their relationships, was done in three positions: maximum intercuspation (Position 1), anterior repositioning splint position (Position 2), and stabilization splint position (Position 3). Disc/condyle coordinate measurements and disc condyle angles were determined and compared. Results: In Position 1, the average disc-condyle angle was 53.4° in the 60 joints with DDwR, while it was −13.3° with Position 2 and 30.1° with Position 3. The frequency of successful "disc recapture" with Position 2 was significantly higher (58/60, 96.7%) than Position 3 (20/60, 33.3%). In Positions 2 and 3, the condyle moved forward and downward while the disc moved backward. The movements were, however, more remarkable with Position 2. Conclusions: Anterior repositioning of the mandible improves the spatial relationship between the disc and condyle in patients with DDwR. In addition to anterior and inferior movement of the condyle, transitory posterior movement of the disc also occurred.


Subject(s)
Humans , Male , Female , Child , Adolescent , Adult , Young Adult , Occlusal Splints , Temporomandibular Joint Disc/injuries , Joint Dislocations/physiopathology , Joint Dislocations/therapy , Mandibular Condyle/injuries , Reference Values , Magnetic Resonance Imaging , Observer Variation , Reproducibility of Results , Analysis of Variance , Treatment Outcome , Temporomandibular Joint Disc/physiopathology , Temporomandibular Joint Disc/diagnostic imaging , Joint Dislocations/diagnostic imaging , Equipment Design , Incisor/physiopathology , Mandibular Condyle/physiopathology , Mandibular Condyle/pathology , Mandibular Condyle/diagnostic imaging
20.
Acta Odontol Scand ; 75(6): 394-401, 2017 Aug.
Article in English | MEDLINE | ID: mdl-28502196

ABSTRACT

OBJECTIVE: The main purpose of the present systematic review was to evaluate the quantitative effects of the pendulum appliance and modified pendulum appliances for maxillary molar distalization in Class II malocclusion. MATERIALS AND METHODS: Our systematic search included MEDLINE, EMBASE, CINAHL, PsychINFO, Scopus and key journals and review articles; the date of the last search was 30 January 2017. We graded the methodological quality of the studies by means of the Quality Assessment Tool for Quantitative Studies, developed for the Effective Public Health Practice Project (EPHPP). RESULTS: In total, 203 studies were identified for screening, and 25 studies were eligible. The quality assessment rated four (16%) of the study as being of strong quality and 21 (84%) of these studies as being of moderate quality. The pendulum appliances showed mean molar distalization of 2-6.4 mm, distal tipping of molars from 6.67° to 14.50° and anchorage loss with mean premolar and incisor mesial movement of 1.63-3.6 mm and 0.9-6.5 mm, respectively. The bone anchored pendulum appliances (BAPAs) showed mean molar distalization of 4.8-6.4 mm, distal tipping of molars from 9° to 11.3° and mean premolar distalization of 2.7-5.4 mm. CONCLUSIONS: Pendulum and modified pendulum appliances are effective in molar distalization. Pendulum appliance with K-loop modification, implant supported pendulum appliance and BAPA significantly reduced anchorage loss of the anterior teeth and distal tipping of the molar teeth.


Subject(s)
Malocclusion, Angle Class II/therapy , Orthodontic Anchorage Procedures/methods , Orthodontic Appliances/statistics & numerical data , Tooth Movement Techniques/instrumentation , Bicuspid/physiopathology , Cephalometry , Female , Humans , Incisor/physiopathology , Male , Molar/physiopathology
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