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BioMed Research International 2017Hypodontia, or tooth agenesis, is the most prevalent craniofacial malformation in humans. It may occur as part of a recognised genetic syndrome or as a nonsyndromic... (Review)
Review
Hypodontia, or tooth agenesis, is the most prevalent craniofacial malformation in humans. It may occur as part of a recognised genetic syndrome or as a nonsyndromic isolated trait. Excluding third molars, the reported prevalence of hypodontia ranges from 1.6 to 6.9%, depending on the population studied. Most affected individuals lack only one or two teeth, with permanent second premolars and upper lateral incisors the most likely to be missing. Both environmental and genetic factors are involved in the aetiology of hypodontia, with the latter playing a more significant role. Hypodontia individuals often present a significant clinical challenge for orthodontists because, in a number of cases, the treatment time is prolonged and the treatment outcome may be compromised. Hence, the identification of genetic and environmental factors may be particularly useful in the early prediction of this condition and the development of prevention strategies and novel treatments in the future.
Topics: Anodontia; Bicuspid; Humans; Incisor; Mandible; Maxilla
PubMed: 28401166
DOI: 10.1155/2017/9378325 -
Progress in Orthodontics Dec 2022The purpose was to determine the predictability of tooth movements through clear aligner among premolar extraction patients and to explore the effects of various factors...
BACKGROUND
The purpose was to determine the predictability of tooth movements through clear aligner among premolar extraction patients and to explore the effects of various factors on tooth movements.
METHODS
A total of 31 extraction patients (10 males and 20 females; age 14-44) receiving clear aligner treatment (Invisalign) were enrolled in this study. The actual post-treatment models and pre-treatment models were superimposed using the palatal area as a reference and registered with virtual post-treatment models. A paired t test was used to compare the differences between actual and designed tooth movements of maxillary first molars, canines, and central incisors. A multivariate linear mixed model was performed to examine the influence of variables on actual tooth movements.
RESULTS
Compared to the designed tooth movements, the following undesirable tooth movements occurred: mesial movement (2.2 mm), mesial tipping (5.4°), and intrusion (0.45 mm) of first molars; distal tipping (11.0°), lingual tipping (4.4°), and distal rotation of canines (4.9°); lingual tipping (10.6°) and extrusion (1.5 mm) of incisors. Age, crowding, mini-implant, overbite, and attachments have differential effects on actual tooth movements. Moreover, vertical rectangular attachments on canines are beneficial in achieving more predictable canine and incisor tooth movements over optimized attachments. Lingual tipping and extrusion of incisors were significantly influenced by the interaction effects between incisor power ridge and different canine attachments (p < 0.05).
CONCLUSIONS
Incisors, canines, and first molars are subject to unwanted tooth movements with clear aligners among premolar extraction patients. Age, crowding, mini-implant, overbite, and attachments influence actual tooth movements. Moreover, vertical rectangular attachments on canines are beneficial in achieving more predictable incisor tooth movements over optimized canine attachments.
Topics: Male; Female; Humans; Bicuspid; Overbite; Tooth Movement Techniques; Malocclusion; Orthodontic Appliances, Removable; Malocclusion, Angle Class II; Multivariate Analysis
PubMed: 36581703
DOI: 10.1186/s40510-022-00447-y -
The Journal of Thoracic and... Jul 2019
Topics: Aorta; Aortic Valve; Bicuspid; Humans; Replantation; Tricuspid Valve
PubMed: 31248515
DOI: 10.1016/j.jtcvs.2018.10.158 -
Medicina Oral, Patologia Oral Y Cirugia... Jul 2011The objective of this study was to estimate the incidence of non-syndromic supernumerary premolars, to classify them and to identify the complications related to them.
OBJECTIVE
The objective of this study was to estimate the incidence of non-syndromic supernumerary premolars, to classify them and to identify the complications related to them.
STUDY DESIGN
This retrospective cohort study was composed of 8400 panoramic radiographs of patients who presented at our Oral and Maxillofacial Surgery Services from January 1998 to May 2008. The number of supernumerary premolars, their localization, the ages and the sex of the patients, any associated complications and treatment methods were estimated.
RESULTS AND CONCLUSION
A total of 20 supernumerary premolar teeth were found in 10 of the 8400 patients (0.24%) with 7 of those being females and three males. Three patients had pain localized to the mental foramen and one patient had resorption in the root of the adjacent tooth. In these series, 18 supernumerary premolar teeth were extracted. In contrast with previous studies, this study suggested that this phenomenon is more frequently encountered in females than in males. The presence of complications associated with the supernumerary premolars in 4 patients necessitated consideration of surgical intervention as a treatment choice for these teeth. Otherwise, they should be kept under observation.
Topics: Adolescent; Adult; Bicuspid; Female; Humans; Incidence; Male; Retrospective Studies; Tooth, Supernumerary; Young Adult
PubMed: 20526261
DOI: No ID Found -
The Angle Orthodontist Nov 2005
Topics: Bicuspid; Biology; Humans; Malocclusion; Molar; Orthodontic Appliance Design; Tooth Movement Techniques
PubMed: 16448227
DOI: 10.1043/0003-3219(2005)75[1084:BO]2.0.CO;2 -
American Journal of Orthodontics and... Oct 2022Orthodontists, surgeons, and patients have taken an interest in using clear aligners in combination with orthognathic surgery. This study aimed to evaluate the accuracy...
INTRODUCTION
Orthodontists, surgeons, and patients have taken an interest in using clear aligners in combination with orthognathic surgery. This study aimed to evaluate the accuracy of tooth movements with clear aligners during presurgical orthodontics using novel 3-dimensional superimposition techniques.
METHODS
The study sample consisted of 20 patients who have completed presurgical orthodontics using Invisalign clear aligners. Initial (pretreatment) digital dental models, presurgical digital dental models, and ClinCheck prediction models were obtained. Presurgical models were superimposed onto initial ones using stable anatomic landmarks; ClinCheck models were superimposed onto presurgical models using surface best-fit superimposition. Five hundred forty-five teeth were measured for 3 angular movements (buccolingual torque, mesiodistal tip, and rotation) and 4 linear movements (buccolingual, mesiodistal, vertical, and total scalar displacement). The predicted tooth movement was compared with the achieved amount for each movement and tooth, using both percentage accuracy and numerical difference.
RESULTS
Average percentage accuracy (63.4% ± 11.5%) was higher than in previously reported literature. The most accurate tooth movements were buccal torque and mesial displacement compared with lingual torque and distal displacement, particularly for mandibular posterior teeth. Clinically significant inaccuracies were found for the buccal displacement of maxillary second molars, lingual displacement of all molars, intrusion of mandibular second molars, the distal tip of molars, second premolars, and mandibular first premolars, buccal torque of maxillary central and lateral incisors, and lingual torque of premolars and molars.
CONCLUSIONS
Superimposition techniques used in this study lay the groundwork for future studies to analyze advanced clear aligner patients. Invisalign is a treatment modality that can be considered for presurgical orthodontics-tooth movements involved in arch leveling and decompensation are highly accurate when comparing the simulated and the clinically achieved movements.
Topics: Bicuspid; Humans; Incisor; Maxilla; Orthodontic Appliances, Removable; Tooth Movement Techniques
PubMed: 36182208
DOI: 10.1016/j.ajodo.2021.12.019 -
The Kaohsiung Journal of Medical... Oct 2005Transposition is described as an interchange in the position of two teeth within the same quadrant of the dental arch. Canine transposition is reportedly the most common...
Transposition is described as an interchange in the position of two teeth within the same quadrant of the dental arch. Canine transposition is reportedly the most common transposition in human dentition. The incidence of maxillary canine-premolar transposition is reported to be 0.135-0.510%. Although the exact mechanism of canine transposition is unclear, it seems to be closely related to genetically influenced, retained deciduous canine, and a history of trauma. In this article, we focus on the classification, incidence, etiology, and treatment modalities of tooth transposition. We hope this information will help clinicians treating patients with this kind of dental anomaly.
Topics: Bicuspid; Cuspid; Diagnosis, Differential; Early Diagnosis; Humans; Incisor; Molar; Radiography; Tooth Abnormalities
PubMed: 16302446
DOI: 10.1016/S1607-551X(09)70148-2 -
The Angle Orthodontist Jul 2023To compare mandibular relative anchorage loss (RAL) under reciprocal anchorage between first and second premolar extraction cases in bimaxillary protrusion mild crowding...
OBJECTIVES
To compare mandibular relative anchorage loss (RAL) under reciprocal anchorage between first and second premolar extraction cases in bimaxillary protrusion mild crowding cases treated using clear aligner therapy (CAT).
MATERIALS AND METHODS
Adult patients who met the following criteria were included: treated using CAT with bilateral mandibular premolar extractions and space closure using intra-arch reciprocal anchorage. RAL was defined as the percent molar mesial movement relative to the sum of molar mesial plus canine distal movement. Movements of the mandibular central incisor (L1), canine (L3), and first molar (L6) were measured based on superimposition of the pre- and post-treatment dentition and jaw models.
RESULTS
Among the 60 mandibular extraction quadrants, 38 had lower first premolar (L4) and 22 had lower second premolar (L5) extracted. L6 mesial movement was 2.01 ± 1.11 mm with RAL of 25% in the L4 extraction group vs 3.25 ± 1.19 mm with RAL of 40% in the L5 extraction group (P < .001). Tooth movement efficacy was 43% for L1 occlusogingival movement, 75% for L1 buccolingual inclination, 60% for L3 occlusogingival movement, and 53% for L3 mesiodistal angulation. L1 had unwanted extrusion and lingual crown torquing whereas L3 had unwanted extrusion and distal crown tipping, on which the power ridges or attachments had little preventive effect.
CONCLUSIONS
The average mandibular reciprocal RAL is 25% or 40% for extraction of L4 or L5, respectively, in CAT cases. A RAL-based treatment planning workflow is proposed for CAT extraction cases.
Topics: Humans; Bicuspid; Tooth Movement Techniques; Molar; Malocclusion; Orthodontic Appliances, Removable
PubMed: 37343197
DOI: 10.2319/102222-727.1 -
The Journal of Thoracic and... Feb 2018
Topics: Aortic Valve; Bicuspid; Bicuspid Aortic Valve Disease; Heart Valve Diseases; Humans; Machine Learning
PubMed: 29198801
DOI: 10.1016/j.jtcvs.2017.10.041 -
The Angle Orthodontist May 2006The aim of this systematic review was to examine, in an evidence-based way, what kind of orthodontic anchorage systems/applications are evaluated and their... (Meta-Analysis)
Meta-Analysis Review
The aim of this systematic review was to examine, in an evidence-based way, what kind of orthodontic anchorage systems/applications are evaluated and their effectiveness. A literature survey from the Pub Med and Cochrane databases covering the period from January 1966 to December 2004 was performed. Randomized controlled trials (RCT), prospective and retrospective controlled studies, and clinical trials comparing at least two anchorage situations were included. Two reviewers selected and extracted the data independently and also assessed the quality of the retrieved studies. The search strategy resulted in 494 articles, of which 14 met the inclusion criteria. Two main anchorage situations were identified: anchorage of molars during space closure after premolar extractions and anchorage loss in the incisor or premolar region (or both) during molar distalization. Because of contradictory results and the vast heterogeneity in study methods, the scientific evidence was too weak to evaluate anchorage efficiency during space closure. Intraoral molar distalization leads to anchorage loss in various amounts depending on the choice of distalization unit. Most of the studies had serious problems with small sample size, confounding factors, lack of method error analysis, and no blinding in measurements. To obtain reliable scientific evidence, controlled RCT's with sufficient sample sizes are needed to determine which anchorage system is the most effective in the respective anchorage situation. Further studies should also consider patient acceptance and cost analysis as well as implants as anchorage.
Topics: Bicuspid; Humans; Incisor; Molar; Orthodontic Anchorage Procedures; Orthodontic Space Closure; Research Design; Serial Extraction; Tooth Movement Techniques
PubMed: 16637733
DOI: 10.1043/0003-3219(2006)076[0493:OA]2.0.CO;2