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1.
Cureus ; 16(7): e65484, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39188466

RESUMO

Midline diastemas are one of the most prevalent dental malocclusions. In young adults this may create aesthetics problems, especially in individuals marked by a gap between central incisors higher than 4 mm. This case report demonstrates the treatment of a patient with Angle's Class I malocclusion and midline diastema with the M-spring appliance resulting in complete closure within four months. The case included a frenectomy for correction of the abnormal labial frenal attachment followed by an M-spring orthodontic appliance. This "M" shaped device, with specific activation points, provides control over tooth movement and consequently achieves this site closure in a short duration of time by tipping the crowns of central incisors in a mesial direction. This procedure aimed to resolve aesthetic issues while also enhancing and ensuring functional occlusion.

2.
Cureus ; 16(7): e65270, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39184616

RESUMO

Orthodontic space closure is a critical aspect of treatment aimed at the correct positioning of teeth and is linked to tooth movement and optimal biomechanics. Therefore, the goal of this case study is to elucidate the process, describing the challenges encountered and the solutions adopted, with a focus on the frictionless technique and the use of devices like the Opus Loop to close spaces. Sliding mechanics, known for high friction, and segmental mechanics, characterized by low friction and continuous adjustment, are two significant technologies used. In this specific case, the frictionless methods applied to a 23-year-old female patient with protruding superior labial incisors included: extraction of the first premolars in all four quadrants, followed by consecutive wiring. Retraction was performed using an Opus Loop, significantly improving the patient's facial profile and dental arch over the next year and a half. As a result, the study demonstrates that the Opus Loop greatly reduces friction forces and offers an effective mechanism to influence tooth movement in orthodontic treatment regimens.

3.
Contemp Clin Dent ; 15(2): 129-134, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39206234

RESUMO

Background: Canine retraction has been successful with various force systems and retraction techniques. The appointment interval for force reactivation in canine retraction along the archwire is 4-8 weeks. Aims: The aim was to evaluate the effect of different reactivation intervals on the rate of space closure. Settings and Design: This split-mouth randomized clinical trial recruited 38 patients indicated for the first premolar extraction. Methods: Monthly digital models were acquired for 6 months. The first premolars were extracted, and temporary anchorage devices were placed for maximum anchorage control. The canines were retracted using elastomeric chains which were replaced every 2, 4, 6, or 8 weeks. The monthly rate of canine retraction was measured. The time to space closure was calculated. The secondary outcome was the mesial drift of the first molars. Statistical Analysis: The Kaplan-Meier survival analysis and the Friedman test evaluated and compared the groups. Results: There was no significant difference between the monthly canine retraction rate or the first molar mesial drift between the groups. The mean time to space closure was 5.74 months in the 2-week reactivation group, which was statistically less than the other groups. Conclusions: The 2-week reactivation interval may reduce time to space closure. Direct anchorage control with miniscrews limited anchorage loss significantly.

4.
Int Orthod ; 22(3): 100895, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38991251

RESUMO

Congenital missing second premolars in growing patients should be accurately evaluated in order to establish a suitable treatment plan. Concerning the decision of whether to close or maintain spaces in the dental arches, it shall also be based on biomechanical aspects and the aesthetic traits of individual patients. Accordingly, the option of closing tooth spaces requires an adequate application of biomechanical principles aimed at avoiding detrimental effects on dental arches and facial profile. An effective use of titanium miniscrews for immediate loading, associated with efficient sliding mechanics, can represent an elective way to successfully treat such cases. Herein, the objective is to describe the procedure and underscore the advantages of the mentioned approach by presenting a clinical case along with long-term follow-up.


Assuntos
Dente Pré-Molar , Parafusos Ósseos , Procedimentos de Ancoragem Ortodôntica , Humanos , Procedimentos de Ancoragem Ortodôntica/métodos , Procedimentos de Ancoragem Ortodôntica/instrumentação , Adolescente , Fenômenos Biomecânicos , Anodontia/terapia , Fechamento de Espaço Ortodôntico/métodos , Técnicas de Movimentação Dentária/métodos , Técnicas de Movimentação Dentária/instrumentação , Feminino , Desenho de Aparelho Ortodôntico , Masculino , Titânio
5.
J Orthod ; : 14653125241256672, 2024 Jul 24.
Artigo em Inglês | MEDLINE | ID: mdl-39049440

RESUMO

AIM: To evaluate the effect of chewing gum on the rate of space closure, oral hygiene, pain during space closure and appliance breakage in patients undergoing fixed appliance therapy. DESIGN: A prospective, single-centre, two-arm, parallel, double-blinded randomised controlled trial. SETTING: Orthodontic unit of a privately funded hospital, Chennai, India. PARTICIPANTS: In total, 28 participants were randomly allocated into a chewing gum group (CGG) (n = 14) or a control group (CG) (n = 14). METHODS: Baseline data were collected at the start of retraction (T0), at 4 weeks (T1), 8 weeks (T2) and 12 weeks (T3) after the start of retraction. Rate of space closure, pain, oral hygiene and appliance breakage were assessed at T1, T2 and T3. Data were analysed using an independent t-test with P < 0.05 considered to be statistically significant. RESULTS: The mean rate of space closure in the CGG was 0.9 ± 0.2 mm/month and 0.8 ± 0.2 mm/month in the CG (P = 0.07, 95% confidence intervals [CI] were 0.80-1.01 for the CGC and 0.70-0.91 for the CG). In both the groups, oral hygiene became worse between T0 and T3. At T0 and T1, participants in the CGG reported less pain at 24 h and 7 days when compared to the CG (P < 0.05). At T2 and T3, participants in the CGG reported less pain at 0 h, 24 h and 7 days when compared to the CG (P < 0.05). Appliance breakage in both groups was minimal, with an odds ratio of 0.7 (95% CI 0.1-3.8) and was similar (P = 0.66). CONCLUSION: There was minimal increase that was clinically not significant in the rate of space closure with chewing gum. Chewing gum ensured better oral hygiene, helped alleviate pain and had no effect on appliance breakage during space closure.

6.
J Korean Assoc Oral Maxillofac Surg ; 50(3): 170-174, 2024 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-38940655

RESUMO

Adenomatoid odontogenic tumor (AOT) is a rare, asymptomatic, slow-growing benign tumor that can be divided into three variants: follicular, extrafollicular, and peripheral. By treating AOT using an enucleation and curettage approach, recurrence can be avoided. We report a case of a 24-year-old female who presented with a lump in the right mandibular premolar area along with diastema between displaced teeth #43 and #44 and was diagnosed with extrafollicular AOT. The patient was managed with enucleation-curettage surgery without additional bone graft procedure along with routine follow-up. A successful outcome without recurrence was achieved, and diastema closure with repositioning of the displaced teeth did not require orthodontic treatment. AOT should be managed via enucleation and curettage to obtain successful outcomes without recurrence. Spontaneous bone regeneration following enucleation can be achieved without guided bone regeneration. Also, diastema closure and repositioning of displaced teeth can occur without orthodontic interventions through physiologic drift.

7.
Front Bioeng Biotechnol ; 12: 1388876, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38903188

RESUMO

Background: Overtreatment design of clear aligner treatment (CAT) in extraction cases is currently primarily based on the clinical experience of orthodontists and is not supported by robust evidence on the underlying biomechanics. This study aimed to investigate the biomechanical effects of overtreatment strategies involving different maxillary anterior teeth intrusion patterns during anterior teeth retraction by CAT in extraction cases. Materials and methods: A finite element model of the maxillary dentition with the first premolar extracted was constructed. A loading method of clear aligners (CAs) based on the initial state field was proposed. The iterative method was used to simulate the long-term orthodontic tooth movement under the mechanical load exerted by the CAs. Three groups of CAs were utilized for anterior teeth retraction (G0: control group; G1: incisors intrusion group; G2: anterior teeth intrusion group). Tooth displacement and occlusal plane rotation tendency were analyzed. Results: In G0, CAT caused lingual tipping and extrusion of the incisors, distal tipping and extrusion of the canines, mesial tipping, and intrusion of the posterior teeth. In G1, the incisors showed minimal extrusion, whereas the canines showed increased extrusion and distal tipping tendency. G2 showed the smallest degree of posterior occlusal plane angle rotation, while the inclination tendency of the canines and second premolars decreased. Conclusion: 1. In CAT, tooth displacement tendency may change with increased wear time. 2. During anterior teeth retraction, the incisor intrusion pattern can provide effective vertical control for the lateral incisors but has little effect on the central incisors. Anterior teeth intrusion patterns can alleviate the inclination of canines and second premolars, resulting in partial relief of the roller-coaster effect.

8.
Angle Orthod ; 94(5): 581-591, 2024 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-38705574

RESUMO

Managing orthodontic treatment for adults with missing permanent teeth can be intricate, especially when dealing with a posterior scissor bite and an impacted tooth. This case report presents successful treatment of a female patient with dental and skeletal Class II malocclusion, high mandibular plane angle, missing maxillary left lateral incisor and mandibular right first molar, as well as right posterior scissor bite, and a deeply impacted mandibular left second premolar. In the maxilla, the right second molar and right lateral incisor were strategically extracted to eliminate the scissor bite and enhance frontal esthetic balance. In the mandible, the edentulous space caused by early loss of the first molar was successfully closed and the impacted second premolar was guided into its proper position after surgical exposure. Finally, symmetric frontal esthetics, well-aligned dentition with ideal intercuspation and an improved profile were achieved, which remained stable in the 17 month follow-up.


Assuntos
Dente Pré-Molar , Incisivo , Má Oclusão Classe II de Angle , Dente Molar , Dente Impactado , Humanos , Feminino , Dente Impactado/terapia , Má Oclusão Classe II de Angle/terapia , Má Oclusão Classe II de Angle/complicações , Incisivo/anormalidades , Cefalometria , Anodontia/terapia , Anodontia/complicações , Extração Dentária , Estética Dentária , Mandíbula , Planejamento de Assistência ao Paciente , Adulto , Técnicas de Movimentação Dentária/métodos , Técnicas de Movimentação Dentária/instrumentação
9.
Cureus ; 16(3): e55522, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38576654

RESUMO

The frenum is a mucous membrane fold that connects the lip and cheek to the gingiva, periosteum, and alveolar mucosa. When the frena are linked too closely to the gingival border, there may be issues with plaque removal, and the overall gingiva may be affected. In addition, the maxillary frenum may provide aesthetic difficulties or interfere with the aesthetic outcome in cases of midline diastema, which may result in a recurrence after treatment. A labial frenectomy, a frequently performed surgical operation in the specialty of dentistry, is used to address such an abnormal frenum. This article describes a case study of a maxillary labial frenectomy using a traditional scalpel approach and topical application of ozonated olive oil.

10.
Int Orthod ; 22(2): 100872, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38613862

RESUMO

The patient presented in this case report is a 10-year-old boy with hyperdivergent skeletal Class II associated with familial genetic agenesis of the second premolars. The treatment plan chosen was to close the spaces of agenesis using a bimaxillary appliance fixed buccally. The advantages and disadvantages of this treatment option were discussed. The result was stable and made it possible to avoid an implant-prosthetic solution, which would undoubtedly have been more restrictive over time.


Assuntos
Anodontia , Dente Pré-Molar , Má Oclusão Classe II de Angle , Aparelhos Ortodônticos Fixos , Humanos , Masculino , Criança , Má Oclusão Classe II de Angle/diagnóstico por imagem , Má Oclusão Classe II de Angle/cirurgia , Anodontia/diagnóstico por imagem , Anodontia/genética , Anodontia/cirurgia , Mentoplastia , Dente Pré-Molar/cirurgia , Cefalometria , Radiografia Dentária , Resultado do Tratamento
11.
J Clin Med ; 13(7)2024 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-38610875

RESUMO

(1) Background: A missing bilateral maxillary lateral incisor (MBMLI) causes aesthetic and functional problems and a multidisciplinary approach is required for treatment. This study aimed to compare the changes in the mesiodistal axial angulations of the maxillary canines and central incisors with orthodontic treatment of MBMLI. (2) Methods: A total of 56 patients with MBMLI were included in the study, and three groups were formed: the control group (Group 1, n = 20) with untreated ideal occlusion and the space opening (Group 2, n = 20) and space closure (Group 3, n = 16) groups as treated study groups. The mesiodistal angulations between the long axes of the maxillary right canine (tooth no 13), right central incisor (tooth no 11), left central incisor (tooth no 21) and maxillary left canine (tooth no 23), and the bicondylar plane, were measured on the panoramic radiographs taken pre (T0) and post treatment (T1). p < 0.05 was accepted for statistical significance. (3) Results: At T0, while there was no significant difference between the mesiodistal angulations of the right-left maxillary canines and central incisors in all groups (p > 0.05), the mesiodistal angulations of the canines in the Group 1 were significantly higher than the study groups (p < 0.05). With treatment, while the mesiodistal angulation of the canines increased in Group 2, it decreased in Group 3 (p < 0.05). On the other hand, the mesiodistal angulation of the central incisors decreased in Group 2 and did not change in Group 3 (p > 0.05). At T1, the mesiodistal angulation of the canines was found to be lower in Group 3 than in Groups 1 and 2, while the angulation of the central incisors was found to be lower in Group 2 compared to Group 1 (p < 0.05). (4) Conclusions: In the orthodontic treatment of MBMLIs, changes in the mesiodistal angulations of the maxillary canine and central incisors should be taken into account for satisfactory outcomes. It was concluded that there should be a tendency to select the space closure method in which normal mesiodistal angulations are obtained in maxillary central incisors for aesthetics and planned incisor position, and also at a low cost.

12.
Cureus ; 16(1): e53241, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38425610

RESUMO

The straight-wire device offers the best finishing potential and control. This case study focuses on the treatment of severe deep bite and Class II malocclusion involving first premolar extraction of the upper arch using a Kalra Simultaneous Intrusion and Retraction loop. Using minimal force and creating enough space for anterior teeth to retract while maintaining the Class II molar relationship was the aim of the therapy. Due to the unsightly excessive maxillary incisor showing at rest, the decision was made to intrude anterior teeth to treat a deep overbite. Good and consistent changes occurred post-treatment.

13.
J World Fed Orthod ; 13(3): 113-122, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38508997

RESUMO

BACKGROUND: Rapid distraction of the periodontal ligament is an effective method to shorten the orthodontic treatment time. The objectives of the present study were to assess the effects of an HYCON device (Adenta GmbH, Germany) on the rate of en masse retraction of the anterior teeth, duration of retraction, anchorage loss, root resorption, and soft tissue changes. METHODS: This study was conducted on 60 female patients aged >18 years, divided randomly into two equal groups: Group 1 comprised 30 patients with HYCON, and group 2 comprised 30 patients with nickel-titanium closed coil springs. Skeletal, dental, and soft tissue changes were evaluated on pre- and post-retraction lateral cephalograms, and the rates of anterior tooth movement and anchorage loss were assessed monthly on the dental casts of the patients. Root resorption was assessed using intraoral periapical radiograph. Student's t test was used for the analysis of parametric data, and the Mann-Whitney U test was used for nonparametric data. RESULTS: HYCON significantly shortened the retraction duration by 3 months. The rate of anterior teeth retraction was two times faster in group 1, compared with group 2. There was a significant difference in the anchorage loss between the groups in only first 2 months of treatment. Group 2 showed significantly more root resorption and soft tissue changes than group 1 (P < 0.05). CONCLUSIONS: HYCON is an effective device for significantly shortening the duration of retraction with anchorage loss of 2 to 2.5 mm. However, careful monitoring for possible root resorption should be performed.


Assuntos
Procedimentos de Ancoragem Ortodôntica , Ligamento Periodontal , Reabsorção da Raiz , Técnicas de Movimentação Dentária , Humanos , Feminino , Técnicas de Movimentação Dentária/instrumentação , Técnicas de Movimentação Dentária/métodos , Reabsorção da Raiz/etiologia , Procedimentos de Ancoragem Ortodôntica/instrumentação , Procedimentos de Ancoragem Ortodôntica/métodos , Cefalometria , Incisivo , Adulto Jovem , Adulto , Adolescente , Osteogênese por Distração/instrumentação , Osteogênese por Distração/métodos , Fios Ortodônticos , Desenho de Aparelho Ortodôntico , Níquel , Fatores de Tempo , Titânio
14.
Angle Orthod ; 94(2): 180-186, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38381800

RESUMO

OBJECTIVES: To assess the success rate of spontaneous space closure after extraction of the first permanent molar (FPM) in the maxilla and the mandible, and to identify the factors that make spontaneous space closure most favorable in each. MATERIALS AND METHODS: A retrospective records-based cohort study was conducted through a search of the database of the Public Dental Service, Stockholm County Council, Stockholm, for young adults born between 2000 and 2001, who underwent extraction of one or more FPM between 2006 and 2016. A total of 995 extracted teeth were identified, of which 203 teeth in 155 patients met the inclusion criteria. RESULTS: Of the 203 extracted teeth, 166 (81.8%) did not receive any orthodontic treatment. The success rate for space closure in orthodontically treated patients was 91.9%. The success rate for spontaneous space closure was 84.3%. All unsuccessful spontaneous space closure in the maxilla occurred in patients older than 12 years. The dental developmental stage of the second permanent molar (SPM) had a statistically significant association with spontaneous space closure in the mandible (P < .001). CONCLUSIONS: The success rate of spontaneous space closure was high (84.3%) and was higher in the maxilla (94.1%) than the mandible (74.1%). Age at time of extraction and dental developmental stage of the SPM were significant factors for successful spontaneous space closure in the maxilla and mandible, respectively.


Assuntos
Dente Molar , Extração Dentária , Adulto Jovem , Humanos , Estudos Retrospectivos , Estudos de Coortes , Dente Pré-Molar , Dente Molar/diagnóstico por imagem , Dente Molar/cirurgia , Radiografia , Mandíbula/diagnóstico por imagem , Mandíbula/cirurgia , Maxila/diagnóstico por imagem , Maxila/cirurgia , Fechamento de Espaço Ortodôntico
15.
Ortho Sci., Orthod. sci. pract ; 17(65): 28-35, 2024. ilus
Artigo em Português | BBO - Odontologia | ID: biblio-1556215

RESUMO

A agenesia dos incisivos laterais superiores compromete a função e a estética, prejudicando o desenvolvimento e autoestima do paciente. O tratamento pode se dar pela abertura dos espaços e reposição dos dentes ausentes por meio de implantes ou reposição mesial dos caninos, seguido pelo seu recontorno em incisivos laterais. A transformação dos caninos em laterais apresenta diversos desafios ao ortodontista devido às diferenças entre torque, volume e cor entre esses dentes, o que, se não devidamente corrigido, pode impactar negativamente no resultado do tratamento. A técnica MBT apresenta diversas versatilidades de bráquetes que podem ser utilizadas com a finalidade de otimizar a movimentação, compensar as diferenças anatômicas e facilitar o tratamento de diversos tipos de casos com arco reto. O caso clínico apresentado mostra o tratamento da agenesia dos incisivos laterais superiores por meio do fechamento de espaço em uma paciente padrão III, com mordida cruzada anterior seguindo a técnica MBT, fazendo uso das relatadas versatilidades de bráquetes de caninos e pré-molares para atingir um posicionamento ideal desses dentes, com as alterações de torque e angulações necessárias. O tratamento incluiu o fechamento de espaços, a extração de pré- -molares inferiores e transformação dos caninos em incisivos laterais, obtendo uma correta relação anterior, oclusão funcional e bom resultado estético.(AU)


Maxillary lateral incisors agenesis compromises the patient's function and aesthetics, impairing the development and self-esteem. Main treatment options are open space for future implant restoration or canine substitution. Canine substitution usually requires restorative treatment to ideally recreate maxillary lateral incisors torque, volume, and color to achieve treatment goals and satisfy the patient's expectations. MBT system presents versatilities that can be used to optimize orthodontic movements, compensate dental anatomic discrepancies, and facilitate some straight-wire cases. This case report describes the orthodontic management of a Class III with anterior cross-bite patient that presented maxillary lateral incisor agenesis. The patient was treated with canine substitution following the MBT technique. Versatilities for canine and premolars were used to achieve the best position, torque, and angulation. The treatment also included mandibular first premolar extraction, space closing, and restorative treatment to re-anatomize the canine into a lateral incisor, achieving proper anterior relation, functional occlusion, and best esthetic result (AU)


Assuntos
Humanos , Feminino , Adulto , Fechamento de Espaço Ortodôntico , Incisivo , Anodontia
16.
Head Face Med ; 19(1): 52, 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-38049867

RESUMO

OBJECTIVES: This study aimed to investigate vertical changes in the maxillary central incisor and the maxillary first molar, along with alterations in the mandibular plane angle during space closure using miniscrew sliding mechanics. METHODS: Twenty adult patients treated at Peking University Hospital of Stomatology between 2008 and 2013 were included. Digital dental models and craniofacial cone-beam computed tomography (CBCT) scans were obtained at the start of treatment (T0) and immediately after space closure (T1). Stable miniscrews were used for superimposing maxillary digital dental models (T0 and T1), and vertical changes in the maxillary first molar and the maxillary central incisor were measured. Three-dimensional changes in the mandibular plane were assessed through CBCT superimposition. RESULTS: The maxillary central incisor exhibited an average extrusion of 2.56 ± 0.18 mm, while the maxillary first molar showed an average intrusion of 1.25 ± 1.11 mm with a distal movement of 0.97 ± 0.99 mm. Additionally, the mandibular plane angle decreased by an average of 0.83 ± 1.65°. All three indices exhibited statistically significant differences. CONCLUSION: During space closure using the miniscrew sliding technique, significant changes occurred in both the sagittal and vertical dimensions of the upper dentition. This included extrusion of the maxillary central incisors, intrusion of the maxillary first molars, and a slight counterclockwise rotation of the mandibular plane.


Assuntos
Procedimentos de Ancoragem Ortodôntica , Técnicas de Movimentação Dentária , Adulto , Humanos , Técnicas de Movimentação Dentária/métodos , Mandíbula/diagnóstico por imagem , Incisivo/diagnóstico por imagem , Dente Molar/diagnóstico por imagem , Maxila/diagnóstico por imagem , Maxila/cirurgia , Cefalometria/métodos , Procedimentos de Ancoragem Ortodôntica/métodos
17.
Prog Orthod ; 24(1): 40, 2023 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-38008884

RESUMO

BACKGROUND: This study aimed to assess the impact of aligner activation and power arm length and material on canine and aligner displacement, von Mises stress in the power arm, and principal stress in the periodontal ligament (PDL) during canine tooth distalization using finite element analysis (FEA). The effects of aligner activation and power arm length were primary outcomes, while the effect of the power arm material was a secondary outcome. METHODS: Aligner activation (0.1 mm or 0.2 mm) was applied without using a power arm in two models. The effects of aligner activation, power arm length (12, 13, or 14 mm) and power arm material (stainless steel [SS] or fiber-reinforced composite [FRC]) on canine distalization were investigated in 12 models by evaluating displacement and stress via ALTAIR OptiStruct analysis. RESULTS: Greater canine displacement was observed in all models with 0.2 mm than 0.1 mm of aligner activation. When models with the same aligner activation were compared, reduced mesiodistal tipping, increased palatal tipping, and increased extrusion of the canine cusp were observed with increasing power arm length. Moreover, the von Mises stress increased as the power arm length increased. Increasing the aligner activation and power arm length increased the maximum principal stress in the PDL. Power arms of the same length in both materials showed the same results in terms of canine displacement, clear aligner displacement, and maximum principal stress in the PDL. However, under conditions of equal length and aligner activation, the von Mises stress of the SS power arm was higher than that of the FRC power arm. CONCLUSION: Using a power arm in canine distalization reduced mesiodistal tipping but increased palatal tipping and extrusion of the canine cusp. Aligner activation and additional force increased tooth movement and principal stress in the canine PDL. FRC power arms exhibited less von Mises stress than SS power arms.


Assuntos
Ligamento Periodontal , Técnicas de Movimentação Dentária , Humanos , Análise de Elementos Finitos , Ligamento Periodontal/fisiologia , Técnicas de Movimentação Dentária/métodos , Estresse Mecânico
18.
Cureus ; 15(10): e47353, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38022208

RESUMO

Class II correction in non-growing patients will always pose a challenge in treatment, especially in a subdivision condition where one quadrant will exhibit class II molar and canine, and the other side will exhibit class I. In such a scenario, a contemporary extraction protocol will face a challenge in symmetric space closure. This case report describes the management of class II subdivision malocclusion by the latest approach, i.e., extraction of a single premolar. At the end of the treatment, midlines were corrected and good functional class I canine relations on both sides were established.

19.
PeerJ ; 11: e15960, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37901473

RESUMO

Background: This study aimed to assess the effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults by cephalometric assessment. Methods: This retrospective study was conducted on 142 cephalograms of patients who underwent orthodontic treatment with premolar extraction in four groups of (I) 40 class I patients with bimaxillary protrusion and maximum anchorage, (II) 40 class I patients with moderate crowding and anchorage, (III) 40 class II patients with maximum anchorage, and (IV) 22 skeletal class III patients with maximum anchorage. The dimensions of the nasopharynx, velopharynx, oropharynx, and hypopharynx, and hyoid bone position were assessed on pre- and postoperative lateral cephalograms using AudaxCeph v6.1.4.3951 software. Data were analyzed by the Chi-square test, paired t-test, and Pearson's correlation test (alpha = 0.05). Results: A significant reduction in oropharyngeal, velopharyngeal, and hypopharyngeal airway dimensions was noted in groups I, III, and IV (P < 0.001), which was correlated with the magnitude of retraction of upper and lower incisors (r = 0.6 - 0.8). In group II, a significant increase was observed in oropharyngeal and velopharyngeal dimensions (P < 0.001). A significant increase in nasopharyngeal dimensions occurred in all groups (P < 0.001). Also, in groups I and III, the position of hyoid bone changed downwards and backwards, which was correlated with reduction in airway dimensions (r = 0.4 - 0.6). Conclusion: According to the present results, extraction orthodontic treatment affects upper airway dimensions and hyoid bone position. Maximum anchorage decreases airway dimensions while moderate anchorage increases airway dimensions.


Assuntos
Osso Hioide , Má Oclusão , Humanos , Adulto , Estudos Retrospectivos , Osso Hioide/diagnóstico por imagem , Fechamento de Espaço Ortodôntico , Dente Pré-Molar , Traqueia
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