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Guarnieri R, Germanò F, Sottile G, Barbato E, Cassetta M. Local factors relating to mandibular canine impaction: A retrospective study. Am J Orthod Dentofacial Orthop 2024; 165:556-564. [PMID: 38310493 DOI: 10.1016/j.ajodo.2023.11.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 11/01/2023] [Accepted: 11/01/2023] [Indexed: 02/05/2024]
Abstract
INTRODUCTION This study aimed to investigate the characteristics of impacted and transmigrated mandibular canines and the association existing between them and some local factors, such as degrees of axial inclination of mandibular incisors, skeletal Class, and mandibular symphysis width. METHODS A retrospective observational study was performed on the medical records and radiographic examination (panoramic radiographs and lateral cephalograms) of 102 orthodontic patients divided into a study group, with at least 1 impacted mandibular canine (51 subjects) and a control group, without mandibular impaction (51 subjects). A chi-square test, t test, and analysis of variance test analysis were used to analyze the data. RESULTS Unilateral and buccal impaction and the presence of the deciduous canine were the more prevalent characteristics of impacted canines, whereas 39.2% presented transmigration. Furthermore, the persistence of the deciduous canine on the impaction side (P <0.0001) and the mesial axial inclination of the impacted canine (P <0.0001) were found to be statistically significant characteristics. A statistically significant association was found between the impaction of the mandibular canine and mandibular incisor to the mandibular plane angle (IMPA) (IMPA, 95.8°; P = 0.009). An additional statistically significant association was found with transmigrated canines (IMPA, 96.8°; P = 0.024). CONCLUSIONS The mesialization of the canine cusp and the persistence of the mandibular deciduous canine are characteristics frequently found in the impaction of the mandibular canine. An accentuated vestibular inclination of the mandibular incisors is significantly associated with mandibular canine impaction.
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Affiliation(s)
- Rosanna Guarnieri
- Department of Oral and Maxillofacial Sciences, School of Dentistry, Sapienza University of Rome, Rome, Italy.
| | - Francesca Germanò
- Department of Oral and Maxillofacial Sciences, School of Dentistry, Sapienza University of Rome, Rome, Italy
| | | | - Ersilia Barbato
- Department of Oral and Maxillofacial Sciences, School of Dentistry, Sapienza University of Rome, Rome, Italy
| | - Michele Cassetta
- Department of Oral and Maxillofacial Sciences, School of Dentistry, Sapienza University of Rome, Rome, Italy
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Kang HK, Pangrazio-Kulbersh V, Kaczynski R, Munoz A. Treatment change comparisons between skeletal Class I and II white adolescents with 3 different vertical divergencies-Part 2: Holdaway difference. Am J Orthod Dentofacial Orthop 2024; 165:357-364. [PMID: 38069924 DOI: 10.1016/j.ajodo.2023.10.012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Revised: 10/01/2023] [Accepted: 10/01/2023] [Indexed: 12/19/2023]
Abstract
INTRODUCTION The Holdaway difference represents the relationship of the NB line to the mandibular incisor (NB-L1) and the bony pogonion (NB-Pog). This study aimed to evaluate treatment changes of NB-L1, NB-Pog, and the Holdaway difference in patients with skeletal Class I and II relationships with 3 different skeletal divergencies. METHODS This retrospective study was the second part of treatment outcome assessments of 135 white adolescent patients (females, n = 69; males, n = 66; mean age, 12.8 ± 1.4 years pretreatment and 15.0 ± 1.4 years posttreatment). The NB-L1, NB-Pog, and Holdaway differences (NB-L1 - NB-Pog) were measured. The mixed-model analysis of variance was used to assess within- and between-subject effects responding to horizontal and vertical skeletal discrepancies. RESULTS For the group with favorable profile changes, the means of the Holdaway difference were maintained in the hypodivergent and normodivergent subgroups and reduced in the hyperdivergent subgroups for patients with skeletal Class I and II relationships. The means of NB-L1 and Holdaway difference were significantly larger in the skeletal Class II group and became greater as skeletal vertical divergencies increased. The NB-Pog means were significantly different only between the hypodivergent and hyperdivergent subgroups. CONCLUSIONS Based on the findings of this study, the Holdaway difference should be adjusted to individualize the incisor positions, considering not only the anteroposterior but also the vertical skeletal relationships of the patients.
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Affiliation(s)
- He-Kyong Kang
- Department of Orthodontics, New York University, New York, NY
| | | | - Richard Kaczynski
- Department of Psychiatry, School of Medicine, Yale University, New Haven, Conn
| | - AnaMaria Munoz
- Department of Orthodontics, New York University, New York, NY.
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Bazán-Mendoza JR, Arias-Modesto PB, Ruíz-Mora GA, Rodríguez-Cárdenas YA, Castillo AAD, Dutra V, Arriola-Guillén LE. Sagittal Position of the Upper Incisor in Relation to the Forehead in Peruvian Individuals with Different Skeletal Relationships. J Contemp Dent Pract 2023; 24:821-825. [PMID: 38238267 DOI: 10.5005/jp-journals-10024-3590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2024]
Abstract
AIM The aim of this study was to determine the sagittal position of the upper incisor considering Andrews' analysis based on the position of the forehead in Peruvian individuals with different skeletal relationships. MATERIALS AND METHODS This retrospective, cross-sectional study included 212 lateral head radiographs of Peruvian individuals (males: 85, mean age 21.38 ± 6.88, and females: 127, mean age 21.18 ± 6.95), with different skeletal relationships (Class I group = 96, Class II group = 57, Class III group = 59). The values of the ANB, SNA, SNB angles as well as the forehead anterior limit line (FALL) and goal anterior limit line (GALL) points were identified in the radiographs, and then a vertical line was drawn in each point to determine if the upper incisor was positioned forward (protruded), backward (retruded) or within (adequate) these lines. Two trained and calibrated investigators performed all the measurements. The Chi-square test was used to evaluate associations. A p-value < 0.05 was considered statistically significant. RESULTS Overall, the sagittal position of the upper incisor showed a significant association with the sagittal skeletal relationship (p = 0.001). The upper incisors showed an adequate position (41.7%), protruded position (56.10%), and retruded position (42.40%), for Class I, II, and III skeletal relationships, respectively, as highest percentages in each Class. Statistical significance was found for females only (p = 0.005). CONCLUSION Skeletal Class I mainly showed an adequate position of the upper central incisor, whereas for Class II a protruded position was most frequently found, and Class III presented a retruded position. CLINICAL SIGNIFICANCE Andrews' analysis based on the position of the forehead in Peruvian individuals is a valuable tool for orthodontic diagnosis. How to cite this article: Bazán-Mendoza JR, Arias-Modesto PB, Ruíz-Mora GA, et al. Sagittal Position of the Upper Incisor in Relation to the Forehead in Peruvian Individuals with Different Skeletal Relationships. J Contemp Dent Pract 2023;24(11):821-825.
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Affiliation(s)
- José Renatto Bazán-Mendoza
- School of Dentistry, Universidad Científica del Sur, Lima, Perú, Orcid: https://orcid.org/0000-0002-2727-0129
| | - Paula Betzabe Arias-Modesto
- School of Dentistry, Universidad Científica del Sur, Lima, Perú, Orcid: https://orcid.org/0000-0002-8875-5365
| | - Gustavo Armando Ruíz-Mora
- Division of Orthodontics, Faculty of Dentistry, Universidad Nacional de Colombia, Bogotá, Distrito Capital, Colombia; Division of Oral and Maxillofacial Radiology, School of Dentistry, Universidad Científica del Sur, Lima, Perú, Orcid: https://orcid.org/0000-0002-9954-1047
| | - Yalil Augusto Rodríguez-Cárdenas
- Division of Oral and Maxillofacial Radiology, School of Dentistry, Universidad Científica del Sur, Lima, Perú; Universidad Nacional de Colombia, Bogotá, Distrito Capital, Colombia, Orcid: https://orcid.org/0000-0002-3107-3013
| | - Aron Aliaga-Del Castillo
- Department of Orthodontics and Pediatric Dentistry, School of Dentistry, University of Michigan, Ann Arbor, Michigan, United States of America, Orcid: https://orcid.org/0000-0003-3963-1742
| | - Vinicius Dutra
- Department of Oral Pathology, Medicine, and Radiology, School of Dentistry, Indiana University, Bloomington, Indiana, United States of America, Orcid: https://orcid.org/0000-0002-0534-3067
| | - Luis Ernesto Arriola-Guillén
- Division of Orthodontics and Division of Oral and Maxillofacial Radiology, School of Dentistry, Universidad Científica del Sur, Lima, Perú, Phone: +51992124507, e-mail: , Orcid: https://orcid.org/0000-0003-0010-5948
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Alpakan ÖO, Türköz Ç, Varlık SK. Long-term stability of mandibular incisor alignment in patients treated nonextraction with or without interproximal enamel reduction. Am J Orthod Dentofacial Orthop 2023; 163:802-810. [PMID: 37245894 DOI: 10.1016/j.ajodo.2022.07.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Revised: 07/01/2022] [Accepted: 07/01/2022] [Indexed: 05/30/2023]
Abstract
INTRODUCTION This study aimed to compare long-term mandibular incisor stability in nongrowing patients with moderate crowding treated nonextraction with and without interproximal enamel reduction (IPR). METHODS Forty-two nongrowing patients with Class I dental and skeletal malocclusion with moderate crowding were divided into 2 groups with an equal number of patients depending on whether IPR was used (IPR group) or not (non-IPR group) during treatment. All patients were treated by the same practitioner and used thermoplastic retainers full-time for 12 ± 1 months at the end of the active treatment. Changes in Peer Assessment Rating scores, Little's irregularity index (LII), intercanine width (ICW), and mandibular incisor inclination (IMPA and L1-NB°) were evaluated using pretreatment, posttreatment, and 8 ± 1 years postretention dental models and lateral cephalograms. RESULTS At the end of the treatment, Peer Assessment Rating scores and LII decreased, and ICW, IMPA, and L1-NB° increased significantly (P <0.001) in both groups. At the end of the postretention period, in both groups, LII increased, and ICW decreased significantly (P <0.001) compared with posttreatment values, whereas IMPA and L1-NB remained stable. When treatment changes were compared, increases in ICW, IMPA, and L1-NB were significantly (P <0.001) higher in the non-IPR group. When postretention changes were compared, the only significant difference between 2 groups was observed in ICW. The decrease in ICW was significantly higher in the non-IPR group. CONCLUSIONS Long-term stability of mandibular incisor alignment in Class I nongrowing patients with moderate crowding treated nonextraction with and without IPR was similar.
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Affiliation(s)
| | - Çağrı Türköz
- Department of Orthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey
| | - Selin Kale Varlık
- Department of Orthodontics, Faculty of Dentistry, Gazi University, Ankara, Turkey.
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Zhou Y, Jiang F, Cheng F, Li J. Detecting representative characteristics of different genders using intraoral photographs: a deep learning model with interpretation of gradient-weighted class activation mapping. BMC Oral Health 2023; 23:327. [PMID: 37231478 DOI: 10.1186/s12903-023-03033-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Accepted: 05/11/2023] [Indexed: 05/27/2023] Open
Abstract
BACKGROUND Sexual dimorphism is obvious not only in the overall architecture of human body, but also in intraoral details. Many studies have found a correlation between gender and morphometric features of teeth, such as mesio-distal diameter, buccal-lingual diameter and height. However, it's still difficult to detect gender through the observation of intraoral photographs, with accuracy around 50%. The purpose of this study was to explore the possibility of automatically telling gender from intraoral photographs by deep neural network, and to provide a novel angle for individual oral treatment. METHODS A deep learning model based on R-net was proposed, using the largest dataset (10,000 intraoral images) to support the automatic detection of gender. In order to reverse analyze the classification basis of neural network, Gradient-weighted Class Activation Mapping (Grad-CAM) was used in the second step, exploring anatomical factors associated with gender recognizability. The simulated modification of images based on features suggested was then conducted to verify the importance of characteristics between two genders. Precision (specificity), recall (sensitivity) and receiver operating characteristic (ROC) curves were used to evaluate the performance of our network. Chi-square test was used to evaluate intergroup difference. A value of p < 0.05 was considered statistically significant. RESULTS The deep learning model showed a strong ability to learn features from intraoral images compared with human experts, with an accuracy of 86.5% and 82.5% in uncropped image data group and cropped image data group respectively. Compared with hard tissue exposed in the mouth, gender difference in areas covered by soft tissue was easier to identify, and more significant in mandibular region than in maxillary region. For photographs with simulated removal of lips and basal bone along with overlapping gingiva, mandibular anterior teeth had similar importance for sex determination as maxillary anterior teeth. CONCLUSIONS Deep learning method could detect gender from intraoral photographs with high efficiency and accuracy. With assistance of Grad-CAM, the classification basis of neural network was deciphered, which provided a more precise entry point for individualization of prosthodontic, periodontal and orthodontic treatments.
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Affiliation(s)
- Yimei Zhou
- State Key Laboratory of Oral Diseases, National Center of Stomatology, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, 14#, 3rd Section, Renmin South Road, Chengdu, 610041, China
| | - Fulin Jiang
- Chongqing University Three Gorges Hospital, Chongqing, 404031, China
| | - Fangyuan Cheng
- Chengdu Boltzmann Intelligence Technology Co., Ltd, Chengdu, China
| | - Juan Li
- State Key Laboratory of Oral Diseases, National Center of Stomatology, West China Hospital of Stomatology, National Clinical Research Center for Oral Diseases, Sichuan University, 14#, 3rd Section, Renmin South Road, Chengdu, 610041, China.
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Sangalli L, Dalessandri D, Bonetti S, Mandelli G, Visconti L, Savoldi F. Proposed parameters of optimal central incisor positioning in orthodontic treatment planning: A systematic review. Korean J Orthod 2022; 52:53-65. [PMID: 35046142 PMCID: PMC8770963 DOI: 10.4041/kjod.2022.52.1.53] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 09/09/2021] [Accepted: 09/29/2021] [Indexed: 11/10/2022] Open
Abstract
OBJECTIVE Planning of incisal position is crucial for optimal orthodontic treatment outcomes due to its consequences on facial esthetics and occlusion. A systematic summary of the proposed parameters is presented. METHODS Studies on Google Scholar©, PubMed©, and Cochrane Library, providing quantitative information on optimal central incisor position were included. RESULTS Upper incisors supero-inferior position (4-5 mm to upper lip, 67-73 mm to axial plane through pupils), antero-posterior position (3-4 mm to Nasion-A, 3-6 mm to A-Pogonion, 9-12 mm to true vertical line, 5 mm to A-projection, 9-10 mm to coronal plane through pupils), bucco-lingual angulation (4-7° to occlusal plane perpendicular on models, 20-22° to Nasion-A, 57-58° to upper occlusal plane, 16-20° to coronal plane through pupils, 108-110° to anterior-posterior nasal spine), mesio-distal angulation (5° to occlusal plane perpendicular on models). Lower incisors supero-inferior position (41-48 mm to soft-tissue mandibular plane), antero-posterior position (3-4 mm to Nasion-B, 1-3 mm to A-Pogonion, 12-15 mm to true vertical line, 6-8 mm to coronal plane through pupils), bucco-lingual angulation (1-4° to occlusal plane perpendicular on models, 87-94° to mandibular plane, 68° to Frankfurt plane, 22-25° to Nasion-B, 105° to occlusal plane, 64° to lower occlusal plane, 21° to A-Pogonion), mesio-distal angulation (2° to occlusal plane perpendicular on models). CONCLUSIONS Although these findings can provide clinical guideline, they derive from heterogeneous studies in terms of subject characteristics and reference methods. Therefore, the optimal incisal position remains debatable.
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Affiliation(s)
- Linda Sangalli
- Dental School, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
- Division of Orofacial Pain, College of Dentistry, University of Kentucky, Lexington, KY, USA
| | - Domenico Dalessandri
- Dental School, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Stefano Bonetti
- Dental School, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Gualtiero Mandelli
- Dental School, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Luca Visconti
- Dental School, Department of Medical and Surgical Specialties, Radiological Sciences and Public Health, University of Brescia, Brescia, Italy
| | - Fabio Savoldi
- Orthodontics, Division of Paediatric Dentistry and Orthodontics, Faculty of Dentistry, The University of Hong Kong, Hong Kong SAR
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Evangelista K, Silva MAGS, Normando D, Valladares-Neto J. Factors associated with the morphology of the mandibular symphysis and soft tissue chin. Dental Press J Orthod 2021; 26:e2119347. [PMID: 34524379 PMCID: PMC8439184 DOI: 10.1590/2177-6709.26.4.e2119347.oar] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Accepted: 04/23/2020] [Indexed: 11/30/2022] Open
Abstract
Objectives: This study aimed to (I) assess the morphology of the symphysis and soft tissue chin associated with sex, age and sagittal/vertical skeletal patterns, and (II) identify the individual and combined contributions of these variables to different portions of the symphysis. Methods: This cross-sectional study included 195 lateral cephalometric radiographs from untreated adults. Alveolar, basal, and soft tissue of the symphysis were measured by an X/Y cranial base coordinate system, and divided in accordance to four predictor variables: sex, age, and sagittal/vertical skeletal patterns. Parametric tests were conducted for comparison and correlation purposes, while multiple regression analysis was performed to explore combined interactions. Results: Alveolar inclination is related to sagittal and vertical patterns, and both explained 71.4% of the variations. Alveolar thickness is weakly predicted and poorly influenced by age. Symphysis height was 10% higher in males, and associated with a vertical skeletal pattern and sex, and both explained 43.6% of variations. Basal symphyseal shows an individual thickness, is larger in males, and vertically short-positioned with age. Soft tissue chin is not necessarily related to the size of the underling skeletal pattern, and enlarges with age, even in adulthood. Conclusions: The symphysis and surrounding tissues are influenced by sex, age, and sagittal and vertical patterns, acting differently on the alveolar, basal and soft tissue portions. Sagittal and vertical skeletal patterns are the strongest association on alveolar symphysis inclination, whereas sex and age acts on the vertical symphysis position and soft tissues thickness.
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Affiliation(s)
- Karine Evangelista
- Universidade Federal de Goiás, Faculdade de Odontologia, Departamento de Ortodontia (Goiânia/GO, Brazil)
| | | | - David Normando
- Universidade Federal do Pará, Faculdade de Odontologia, Departamento de Ortodontia (Belém/PA, Brazil)
| | - José Valladares-Neto
- Universidade Federal de Goiás, Faculdade de Odontologia, Departamento de Ortodontia (Goiânia/GO, Brazil)
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Tamimi ZZ, Abu Alhaija ES, AlWahadni AM, Al-Ajlouni Y. Bite force changes after surgical correction of mandibular prognathism in subjects with increased vertical dimension : A prospective clinical trial. J Orofac Orthop 2021:10.1007/s00056-021-00345-8. [PMID: 34463788 DOI: 10.1007/s00056-021-00345-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 07/13/2021] [Indexed: 11/24/2022]
Abstract
PURPOSE Occlusal bite force (OBF) is the most important parameter in assessing biting efficiency. The aim of this study was to record OBF changes after surgical correction of high angle maxillary/mandibular (Max/Mand) class III patients and to compare these with that recorded in class III patients with average Max/Mand angle. MATERIALS AND METHODS Initially included were 42 patients with severe class III skeletal malocclusion who were scheduled for orthodontic surgery: group 1-22 patients with increased vertical relationship scheduled for bimaxillary surgery; group 2-20 patients with average vertical relationship scheduled for mandibular setback only. OBF measurements before surgery (T0), at debonding (T1) and at least 3 months after debonding (T2) were recorded using a portable occlusal force gauge. The following were also measured: maximum OBF (MOBF) achieved by the subject on each side, averaged OBF on each side (AOBF) and maximum OBF at the incisal region (MIOBF). At T2, only 33 patients (group 1: 17 and group 2: 16) were included in the analysis due to loss to follow-up. RESULTS MOBF increased significantly in group 1, while no significant changes were detected in group 2. MIOBF increased after surgical correction in both groups. Significant increase in MIOBF was observed at T1 (P < 0.001) followed by an insignificant decrease during the observation period (3-6 months after treatment; P > 0.05). The two groups differed significantly in MOBF at T1 and T2, while no statistically significant differences were detected between the groups for MIOBF changes at the various time intervals (P > 0.05). The number of posterior teeth with occlusal contacts increased in both groups. Relapse was detected in group 1 where the number of posterior teeth in contact decreased during the observation period (T1-T2). CONCLUSION OBF greatly improved after surgical correction of the vertical morphology. Correction of high angle mandibular prognathism improves oral function in addition to esthetics.
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Affiliation(s)
- Zaid Z Tamimi
- Division of Oral Surgery, Department of Oral Medicine and Oral Surgery, Faculty of Dentistry, Jordan University of Science and Technology, P.O. Box 3030, Irbid, Jordan.
| | | | - Ahed M AlWahadni
- Department of Prosthodontics, Faculty of Dentistry, Jordan University of Science and Technology, P.O. Box 3030, Irbid, Jordan
| | - Yazeed Al-Ajlouni
- Department of Oral Medicine and Surgery, Faculty of Dentistry, Jordan University of Science and Technology, P.O. Box 3030, Irbid, Jordan
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Personalized Orthodontics: From the Sagittal Position of Lower Incisors to the Facial Profile Esthetics. J Pers Med 2021; 11:jpm11080692. [PMID: 34442336 PMCID: PMC8402232 DOI: 10.3390/jpm11080692] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 01/08/2023] Open
Abstract
Background: One of the goals of orthodontic treatment is to obtain maximum facial harmony. The sagittal position of the lower incisors plays a significant role in the planning of orthodontic treatment. The aim of the study was to evaluate the relationship between the sagittal position of lower incisors and facial profile esthetics with reference to the skeletal vertical dimension. Methods: There were 200 patients included in the study. Patients were allocated into three groups, depending on the vertical growth pattern: normal-angle, low-angle, and high-angle cases. Tweed–Merrifield cephalometric analysis was used to assess the sagittal and vertical position of the mandible, as well as to assess the sagittal position of the lower incisors. Results: Z-angle and Frankfort mandibular incisor plane angle (FMIA) decreased significantly (p < 0.001) with the increase of the skeletal vertical dimension. Incisor mandibular plane angle (IMPA) was significantly higher (p < 0.001) in low-angle patients compared to the high-angle ones. Z-angle appeared to be the most accurate parameter (area under curve, AUC = 0.957) describing patients with a convex profile. The cutoff value of Z-angle 68.0° was characterized by the sensitivity of 94.1% and the specificity of 84.3%. Conclusions: The sagittal position of the lower incisors significantly affects the facial profile convexity. The Z-angle is the parameter which most accurately describes the patients with a convex profile.
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Implications of pretreatment incisor inclinations for the achievement of cephalometric normal values-a study on two patient collectives. J Orofac Orthop 2021; 83:181-194. [PMID: 34232329 DOI: 10.1007/s00056-021-00320-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 05/10/2021] [Indexed: 10/20/2022]
Abstract
PURPOSE The objective was to clarify whether standardized multibracket therapies-differing only in finishing-wire dimensions (0.016 × 0.022 inch vs. 0.017 × 0.025 inch CNA [Connecticut New Archwire]) and excluding any extraction treatment or additional appliances other than intermaxillary elastics-can produce normal incisor inclinations starting from different baseline inclinations. METHODS We analyzed pre- and posttreatment cephalograms of 156 patients (age: 15.6 ± 1.3 years) treated with Roth system (0.018 inch slot). Each archwire group (n = 89 or 67) was divided into subjects with initially retroclined, orthograde, or proclined upper and/or lower incisors (U1, L1). For the resultant 12 subgroups, descriptive statistics were compiled relative to five reference planes (NL, ML, NA, NB, BOP), followed by multiple intragroup (Kolmogoroff-Smirnoff and Wilcoxon signed-rank test) and intergroup (Kruskal-Wallis and Mann-Whitney U test) comparisons relative to NL or ML. RESULTS The following intra- (1, 2) and intergroup (3, 4) differences were statistically significant (p ≤ 0.05) in both archwire groups: (1) post- vs. pretreatment inclinations in the subgroups initially retroclined U1, retroclined L1 and orthograde U1, but without normal values being achieved (subgroups retroclined U1, L1) or preserved (subgroup orthograde U1); (2) observed vs. expected alterations for the subgroups initially orthograde and proclined U1 and L1; (3) posttreatment inclinations for the subgroups initially retroclined vs. orthograde L1 and proclined L1; (4) observed alterations for the subgroups initially retroclined vs. proclined U1 and L1, but neither retroclined nor proclined vs. orthograde. Archwire thickness influenced the outcome to only a limited extent under the special circumstances of this study. CONCLUSION The bracket/archwire combinations evaluated did not lead to normal incisor inclinations in most cases. Posttreatment values did significantly depend on the pretreatment situation. Most frequently, alterations were protrusive in direction, which notably even included incisors that showed norm values at the outset of treatment. It can be concluded that bracket torque will influence but not dominate incisor inclinations.
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Akan S, Keçik D. Lower Incisor Inclination in Relation to Head Posture, Tongue and Hyoid Positions. CUMHURIYET DENTAL JOURNAL 2019. [DOI: 10.7126/cumudj.553220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Mazurova K, Kopp JB, Renkema AM, Pandis N, Katsaros C, Fudalej PS. Gingival recession in mandibular incisors and symphysis morphology-a retrospective cohort study. Eur J Orthod 2019. [PMID: 28637273 DOI: 10.1093/ejo/cjx046] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Objective To evaluate if the morphology of the mandibular symphysis is associated with the development of gingival recession. Materials and methods A cohort of 177 patients was followed longitudinally for up to 5 years post-treatment. Based on the width of the symphysis, participants were divided into three groups: narrow (n = 57); average (n = 63), and wide symphysis (n = 57). Morphology of the symphysis and inclination of incisors were measured on lateral cephalometric radiographs before treatment (Ts), at the end of treatment (T0) and 5 years after treatment (T5). Gingival recession and the change of clinical crown heights in mandibular incisors were measured on plaster models made at TS, T0, and T5. Results From TS to T5 the change in inclination was comparable in the narrow, average, and wide groups. At T5, gingival labial recession was present in 19.3 per cent of patients with narrow symphysis, 20.6 per cent with average symphysis, and 14 per cent of patients with wide symphysis. The difference was not significant. The mean change of clinical crown height was <1 mm (TS - T5). The regression model showed some evidence that incisor inclination at Ts might have been associated with the change of mean clinical crown height (-2.51, 95% CI: -4.6 to -0.4, P = 0.02). The logistic regression model demonstrated that H1 (Height 1) might be associated with the development of gingival recession (OR = 0.75, 95% CI: 0.58 to 0.96, P = 0.03). Conclusion Within the limitations of this study, there is no evidence that the overall morphology of the mandibular symphysis is associated with gingival recession development.
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Affiliation(s)
- Katarina Mazurova
- Department of Orthodontics, Palacký University Olomouc, Czech Republic
| | - Jean-Baptiste Kopp
- Department of Orthodontics and Dentofacial Orthopedics, University of Bern, Switzerland
| | - Anne Marie Renkema
- Department of Orthodontics and Craniofacial Biology, Radboud University Nijmegen Medical Centre, The Netherlands
| | - Nikolaos Pandis
- Department of Orthodontics and Dentofacial Orthopedics, University of Bern, Switzerland
| | - Christos Katsaros
- Department of Orthodontics and Dentofacial Orthopedics, University of Bern, Switzerland
| | - Piotr S Fudalej
- Department of Orthodontics, Palacký University Olomouc, Czech Republic.,Department of Orthodontics and Dentofacial Orthopedics, University of Bern, Switzerland
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13
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Abstract
Objective: To investigate the age- and gender-related changes in upper and lower incisors' position and inclination in different vertical craniofacial relationships. Materials and Methods: A retrospective study on patients' records of age 8–48 years. The sample was divided based on Frankfort mandibular plane angle into three groups; normal, high, and low angle groups. It was then subdivided according to age. Upper and lower incisors' inclinations and positions were assessed from lateral cephalometric radiographs. Gender and age associations and effects size were calculated using two-way ANOVA tests. Significance level was set at P < 0.05. Results: Four hundred and twenty records (F = 272, M = 148) were included; 115 had normal, 81 low, and 250 had high vertical relationships with no significant age and gender distribution differences (P > 0.05). All significant associations and effects were found in the low angle group only. A significant association was found between gender and upper incisor inclination (P < 0.05) with medium effect size (0.13 ≤ ηp2 < 0.26). An association is also found between age × gender interaction and upper incisor inclination and lower incisor position (P < 0.05) with large effect size (0.26 ≤ ηp2). Conclusion: Age- and gender-related upper and lower incisor changes were found to be significant in subjects with decreased vertical skeletal pattern only. The upper incisor inclination and the lower incisor position were the most affected variables with age and gender.
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Affiliation(s)
- Amal I Linjawi
- Department of Orthodontics, Faculty of Dentistry, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia
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14
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Mazurova K, Renkema AM, Navratilova Z, Katsaros C, Fudalej PS. No association between gingival labial recession and facial type. Eur J Orthod 2016; 38:286-91. [PMID: 26136434 PMCID: PMC4914901 DOI: 10.1093/ejo/cjv042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
OBJECTIVE To evaluate if facial type is a predictor of the development of gingival recession. METHODS A cohort of 179 orthodontic patients (76 males, 101 females; age before treatment T S = 12.4 years, SD = 0.8) were followed until 5 years post-treatment (T 5 = 20.7 years, SD = 1.2). The presence of recessions was scored ('Yes' or 'No') by two raters on initial (T S), end of treatment (T 0), and post-treatment (T 5) plaster models. A recession was noted (scored 'Yes') if the labial cemento-enamel junction was exposed. The clinical crown heights were measured at T S, T 0, and T 5 as the distances between the incisal edges and the deepest points of the curvature of the vestibulo-gingival margins. Determination of the facial type was based on the inclination of mandibular plane relative to cranial base (Sella-Nasion/Mandibular Plane) and the proportion of posterior to anterior face heights (PFHs; SGo/NMe × 100 per cent) on pre-treatment cephalograms. RESULTS From T 0 to T 5, the number of subjects with recessions increased from 2 (1.1 per cent) to 24 (13.6 per cent), and the number of recession sites increased from 2 to 39. However, most patients had either one or two recession sites. The mean clinical crown height of mandibular incisors increased by 0.86mm (SD = 0.82, P < 0.001). Regression analysis showed that mandibular plane inclination had no effect on the development of gingival recession or on the increase of clinical crown heights of mandibular incisors. CONCLUSIONS Facial type is not a predictor of the occurrence of gingival recession.
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Affiliation(s)
- Katerina Mazurova
- Department of Orthodontics, Palacky University, Olomouc, Czech Republic
| | - Anne-Marie Renkema
- Department of Orthodontics and Craniofacial Biology, Radboud University Medical Centre, Nijmegen, The Netherlands
| | | | - Christos Katsaros
- Department of Orthodontics and Dentofacial Orthopedics, University of Bern, Switzerland
| | - Piotr S Fudalej
- Department of Orthodontics, Palacky University, Olomouc, Czech Republic, Department of Orthodontics and Dentofacial Orthopedics, University of Bern, Switzerland
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