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Progress in Orthodontics Jul 2023Maxillary molar distalization is a common technique used in the non-extraction treatment of Angle Class II malocclusion that can effectively correct the molar...
BACKGROUND
Maxillary molar distalization is a common technique used in the non-extraction treatment of Angle Class II malocclusion that can effectively correct the molar relationship and create spaces for anterior teeth alignment. However, this approach may also impact the temporomandibular joint (TMJ) due to predictable changes in the posterior vertical dimension. Despite its widespread use, Class II malocclusions correction by molar distalization with clear aligners has not been investigated for their effects on the TMJ. Therefore, this study aimed to analyze the impact of sequential molar distalization using clear aligners on the TMJ.
METHODS
Three-dimensional CBCT scans of 23 non-growing patients (7 males, 16 females; mean age 29.8 ± 4.6 years) with skeletal class I or II malocclusion and a bilateral molar class II relationship treated by sequential upper molars distalization with orthodontic clear aligners (Invisalign, Align Technology, San Josè, Ca, USA). A total of 46 joints were examined before and after molar distalization using Anatomage InvivoDental 6.0.3. Linear and angular measurements of the mandibular joint were measured, including joint parameters, inclination, position, and the dimension of the condyle and articular fossa. In addition, 3D volumetric spaces of the joint were analyzed. All data were statistically analyzed by paired T test to determine the differences between the pre-and post-orthodontic procedures.
RESULTS
No statistically significant differences were found in all primary effects resulting from maxillary molars distalization by clear aligners on TMJ components measurements and joint spaces between T0 and T1. Meanwhile, statistically significant differences were observed in the linear position of the upper molars and the molar relationship parameter with at least P ≤ 0.05.
CONCLUSION
Treatment by sequential upper molars distalization with clear aligners does not lead to significant TMJ parameters changes in condyle and fossa spaces, dimensions, and positions.
Topics: Adult; Female; Humans; Male; Malocclusion; Malocclusion, Angle Class II; Maxilla; Molar; Orthodontic Appliances, Removable; Temporomandibular Joint; Tooth Movement Techniques; Cone-Beam Computed Tomography
PubMed: 37455279
DOI: 10.1186/s40510-023-00474-3 -
European Journal of Paediatric Dentistry Dec 2023Molar incisor hypomeralisation (MIH) is a dental condition clinically characterised by the presence of morphological and qualitative enamel defects involving the...
AIM
Molar incisor hypomeralisation (MIH) is a dental condition clinically characterised by the presence of morphological and qualitative enamel defects involving the occlusal and/or incisal third of one or more permanent molars or incisors. Its worldwide prevalence ranges between 2.4 and 40%. Several harmful conditions, such as genetic or medical problems during pregnancy, may act together and increase the risk of MIH. The main objective of this systematic review is to assess whether there is a correlation between MIH and dental caries in mixed or permanent dentition.
METHODS
An electronic search was performed on PubMed (Medline), Scopus and Cochrane Library for articles published from August 2022 to April 2023. Cohort, cross-sectional, retrospective and prospective studies were included. In vitro and animal studies, as well as clinical cases and systematic reviews, were excluded. Studies not differentiating between mixed and permanent dentition were excluded. The observed variables were DMFT (Decayed Missed Filled Teeth) score, DMFS (Decayed Missed Filled Surface) and DMF scores related to FPM (First Permanent Molar) and the clinical prevalence of MIH.
CONCLUSION
DMFT, DMFS and DMFT on FPM scores are significantly different between the group of patients with MIH and the control group. The available evidence supports a correlation between MIH lesions and caries. Caries indexes scores increase proportionally to the severity of MIH.
Topics: Animals; Female; Pregnancy; Humans; Child; Cross-Sectional Studies; Dental Caries; Dental Caries Susceptibility; Molar Hypomineralization; Prevalence; Prospective Studies; Retrospective Studies; Molar
PubMed: 38015112
DOI: 10.23804/ejpd.2023.1985 -
Journal of Dental Research Dec 2023Machine learning (ML) models, especially deep neural networks, are increasingly being used for the analysis of medical images and as a supporting tool for clinical...
Machine learning (ML) models, especially deep neural networks, are increasingly being used for the analysis of medical images and as a supporting tool for clinical decision-making. In this study, we propose an artificial intelligence system to facilitate dental decision-making for the removal of mandibular third molars (M3M) based on 2-dimensional orthopantograms and the risk assessment of such a procedure. A total of 4,516 panoramic radiographic images collected at the Center of Dental Medicine at the University of Zurich, Switzerland, were used for training the ML model. After image preparation and preprocessing, a spatially dependent U-Net was employed to detect and retrieve the region of the M3M and inferior alveolar nerve (IAN). Image patches identified to contain a M3M were automatically processed by a deep neural network for the classification of M3M superimposition over the IAN (task 1) and M3M root development (task 2). A control evaluation set of 120 images, collected from a different data source than the training data and labeled by 5 dental practitioners, was leveraged to reliably evaluate model performance. By 10-fold cross-validation, we achieved accuracy values of 0.94 and 0.93 for the M3M-IAN superimposition task and the M3M root development task, respectively, and accuracies of 0.9 and 0.87 when evaluated on the control data set, using a ResNet-101 trained in a semisupervised fashion. Matthew's correlation coefficient values of 0.82 and 0.75 for task 1 and task 2, evaluated on the control data set, indicate robust generalization of our model. Depending on the different label combinations of task 1 and task 2, we propose a diagnostic table that suggests whether additional imaging via 3-dimensional cone beam tomography is advisable. Ultimately, computer-aided decision-making tools benefit clinical practice by enabling efficient and risk-reduced decision-making and by supporting less experienced practitioners before the surgical removal of the M3M.
Topics: Humans; Molar, Third; Artificial Intelligence; Dentists; Tooth, Impacted; Tooth Extraction; Mandible; Professional Role; Molar; Machine Learning; Radiography, Panoramic; Cone-Beam Computed Tomography; Mandibular Nerve
PubMed: 37944556
DOI: 10.1177/00220345231200786 -
Clinical Oral Investigations Jan 2024The study endeavors to undertake a bibliometric analysis on molar distalization, with the objective of illuminating its evolutionary trajectory, current status, and... (Review)
Review
OBJECTIVES
The study endeavors to undertake a bibliometric analysis on molar distalization, with the objective of illuminating its evolutionary trajectory, current status, and prognosticating future research hotspots and trends.
MATERIAL AND METHODS
A comprehensive exploration of the literature on molar distalization was carried out by conducting a search in the Web of Science (WOS) core database of the University of Hong Kong Electronic Library. The search for topic terms employed included "molar distalization," "molar distalisation," "move molar distally," "molar distal movement," and "molar backwards." The search results were subsequently subjected to meticulous analysis using CiteSpace software. This analysis encompassed various facets such as the citation count; the geographical distribution of the countries, institutions, and journals responsible for publishing the articles; the distribution of the authors; the utilization of keywords within the articles; and the analysis of references.
RESULTS
A total of 516 articles were included in the analysis. The top 5 countries in terms of the number of published papers were the United States (USA), South Korea, Turkey, Italy, and Germany, and the top 5 institutions in terms of the number of published papers were Kyung Hee University, A.T. Still University of Health Sciences, Catholic University of Korea, Seoul St. Mary's Hospital, and Universidade de Sao Paulo. The top 5 authors in terms of the number of published papers were Park, Kook, Bayome, Janson, and Lee. There was little cooperation overall. The top 3 journals in terms of the most published related articles were all orthodontic-related journals. After molar distalization and anchorage, the most frequently used keywords were distalization, movement, and pendulum appliance. Kinzinger GSM is the most frequently cited author in references, and one of his articles also has the highest centrality score in references.
CONCLUSIONS
As the tides of time shift and scholars display an ever-growing dedication to unraveling the intricacies of this therapeutic modality, the realm of molar distalization has undergone notable advancements in technology. Initially, the traditional appliance suffered from aesthetic drawbacks and discomfort. However, contemporary iterations of the appliance have transcended these limitations, boasting enhanced elegance and convenience while concurrently elevating their efficacy. Nevertheless, limitations of current appliances, including their durability and propensity for recurrence post-treatment, continue to necessitate further advancement. Hence, the ongoing scientific inquiry aims to delve deeper into refining treatment modalities and fabricating cutting-edge appliances within this realm.
CLINICAL RELEVANCE
This study holds the potential to significantly enhance the ability of orthodontists to devise treatment protocols and offer state-of-the-art clinical recommendations, thereby empowering them to deliver advanced and refined orthodontic interventions.
Topics: Humans; Orthodontic Appliances; Tooth Movement Techniques; Brazil; Esthetics, Dental; Molar; Bibliometrics
PubMed: 38286861
DOI: 10.1007/s00784-024-05520-w -
Organogenesis Dec 2023It is known to all that Wnt signaling pathway plays an important role in the early development of tooth. Our previous research found that Wnt signaling pathway played... (Review)
Review
It is known to all that Wnt signaling pathway plays an important role in the early development of tooth. Our previous research found that Wnt signaling pathway played crucial roles in dental development, and mutations in antagonist of Wnt signaling pathway may lead to the formation of supernumerary teeth. However, the expression pattern of Wnt signaling molecules in early development of tooth, especially genes with stage specificity, remains unclear. Hence, we applied RNA-seq analysis to determine the expression levels of wnt signal molecules at five different stages of rat first molar tooth germ. In addition, after literature review we summarized the function of Wnt signaling molecules during tooth development and the relationship between Wnt signaling molecules variation and tooth agenesis. Our research may have implications for exploring the role of Wnt signaling molecules in different stages of tooth development.
Topics: Rats; Animals; Wnt Signaling Pathway; Odontogenesis; Wnt Proteins; Tooth; Molar
PubMed: 37194731
DOI: 10.1080/15476278.2023.2212583 -
Acta Medica Academica Aug 2023This study aimed to analyze the crown and root morphology of maxillary and mandibular third molars, and assess their position in relation to adjacent anatomical...
OBJECTIVE
This study aimed to analyze the crown and root morphology of maxillary and mandibular third molars, and assess their position in relation to adjacent anatomical structures using clinical examination and radiographic images.
MATERIALS AND METHODS
A total of 176 extracted impacted or partially impacted third molars were included in this study. Orthopantomogram images (OPG) were used to evaluate the number of roots, position, depth of impaction relative to the occlusal plane of the second molar, and angulation of maxillary and mandibular third molars. The extracted teeth were examined to determine the actual number of roots. The root morphology was classified using the Alavi classification system for maxillary third molars and the Machado classification for mandibular third molars. Additionally, the number of cusps, crown dimensions, and morphology were analyzed using digital and dental calipers.
RESULTS
The extracted samples exhibited a significantly higher number of roots compared to the number assessed on OPG images (P<0.001). The majority of mandibular third molars had two fused roots (37.39%) and a five-cuspid crown (48.70%), while maxillary third molars had three fused roots (26.23%) and four cusps (42.62%). Both maxillary (60.66%) and mandibular third molars (61.74%) were predominantly vertically positioned. Regarding the depth of impaction, maxillary third molars were primarily classified as Class C (65.57%), while mandibular third molars were classified as Class B (47.83%). Differences in crown shape were observed, with maxillary crowns being mostly triangular (36.07%) and mandibular crowns being oval (38.26%). Maxillary third molars had shorter crowns compared to mandibular third molars (P<0.05).
CONCLUSION
The root morphology of maxillary and mandibular third molars in the population of Bosnia and Herzegovina displays variability. Orthopantomogram imaging was found to be inadequate for accurate determination of the number of roots in third molars. The number of cusps on third molars cannot be relied upon as a predictor of the number of roots. The study's findings will have implications for dental practice, particularly for oral surgeons and restorative dentists.
Topics: Humans; Molar, Third; Tooth Root; Molar; Crowns; Radiography
PubMed: 37933504
DOI: 10.5644/ama2006-124.407 -
Medicine Nov 2023Intentional replantation and dental autotransplantation are 2 similar techniques both involving atraumatic tooth extraction, visualization of the root, and replantation....
BACKGROUND
Intentional replantation and dental autotransplantation are 2 similar techniques both involving atraumatic tooth extraction, visualization of the root, and replantation. They are considered as the last resort for unsalvageable teeth. The author aims to describe 2 mandibular posterior teeth with serious periapical lesions which are resolved by intentional replantation and dental autotransplantation, respectively.
CASE SUMMARY
In case 1, a 45-year-old male patient received root canal treatment because of a cracked mandible right first molar with periapical lesions. An endodontic file was separated in the apical third of the mesiolingual root canal. After conventional canal filling of the other root canals, the molar was atraumatically extracted. The separated instrument was removed, the mesiolingual root received a retrograde filling and the molar was replanted. At the 3-month follow up, the patient was asymptomatic and the X-ray picture showed no detectable root resorption and ankylosis. In case 2, a 29-year-old woman reported discomfort during occlusal loading after a root canal treatment and a coronal restoration of the mandibular right first molar. Radiographs showed a low-density shadow in the mesial apical and in the root furcation area of the mandibular first molar so the patient was diagnosed as chronic periapical periodontitis. After the removal of the affected tooth, the extraction socket was thoroughly debrided and irrigated. The intact mandibular right third molar with similar dimensions was extracted by minimally invasive procedure and transplanted. The donor tooth was fixed by a fiber-splint for 1 month and a root canal treatment was performed 2 weeks after surgery. After 1 year, clinical and radiographical examination revealed functional and periodontal healing.
CONCLUSIONS
These 2 reports present the successful management of intentional replantation and dental autotransplantation. Both procedures are recommended after nonsurgical endodontic treatment, especially when apical microsurgery is not an option, for example because of difficult accessibility or patient preference.
Topics: Male; Female; Humans; Adult; Middle Aged; Tooth Replantation; Transplantation, Autologous; Molar; Tooth Root; Root Canal Therapy; Mandible
PubMed: 37986277
DOI: 10.1097/MD.0000000000035822 -
European Archives of Paediatric... Dec 2023Molar incisor hypomineralization (MIH) is playing an increasingly important role in dental practice. MIH is defined as hypomineralization of systemic origin of one to...
PURPOSE
Molar incisor hypomineralization (MIH) is playing an increasingly important role in dental practice. MIH is defined as hypomineralization of systemic origin of one to four permanent first molars, often associated with affected incisors. Affected teeth are more susceptible to caries and post-eruptive enamel loss and should be diagnosed and treated as early as possible. In 2016, the Würzburg concept was developed for German-speaking countries including a classification index-the MIH Treatment Need Index (MIH-TNI)-and a treatment plan based on it for the use in daily practice. In the meantime, the concept has also gained international recognition. The aim of this paper is to update part 2 of the Würzburg concept, the treatment plan, as knowledge about MIH has increased and the disease has been studied more extensively in the last years. Other treatment approaches are now available and therefore need to be included in the concept. Although, the evidence of the different treatment options is still weak, practitioners need guidance in their daily practice.
METHODS
The authors reviewed the available literature, including clinical and laboratory studies and published guidelines.
RESULTS
The updated version of the Würzburg concept includes additional non-invasive strategies and temporary therapy options, as well as treatment approaches for incisors. It therefore covers currently available treatment modalities for MIH-affected teeth, ranging from prophylaxis, non-invasive treatment to restorative approaches and possibly even extraction.
CONCLUSIONS
This is intended to help guide the practitioner and will need to be further validated by clinical trials.
Topics: Humans; Dental Enamel Hypoplasia; Molar Hypomineralization; Dental Enamel; Incisor; Molar; Prevalence
PubMed: 37856065
DOI: 10.1007/s40368-023-00848-5 -
Progress in Orthodontics Dec 2023The aim of this study was to evaluate the distal movement, vertical movement, distal tipping and crown buccal torque of maxillary molars after the completion of...
BACKGROUND
The aim of this study was to evaluate the distal movement, vertical movement, distal tipping and crown buccal torque of maxillary molars after the completion of distalization by comparing the predicted movement with the achieved movement using palatal rugae registration.
METHODS
The study included 22 clear aligner patients (7 males and 15 females), and 79 molars were measured. Two digital models were generated before treatment and after molar distalization and were superimposed after selecting the palatal rugae area for registration in GOM inspect suite software 2022 (GOM; Braunschweig, Germany). The predicted and achieved movements of molar distalization, intrusion, distal tip and crown buccal torque were measured and compared.
RESULT
The achieved distalization (1.25 ± 0.79 mm vs. 2.17 ± 1.03 mm, P < 0.001; 1.41 ± 1.00 mm vs. 2.66 ± 1.15 mm, P < 0.001), intrusion (0.47 ± 0.41 mm vs. 0.18 ± 0.54 mm, P < 0.01; 0.58 ± 0.65 mm vs. 0.10 ± 1.12 mm, P < 0.01), distal tip (5.30 ± 4.56° vs. 1.53 ± 2.55°, P < 0.001; 4.87 ± 4.50° vs. - 1.95 ± 4.32°, P < 0.001) and crown buccal torque (1.95 ± 4.18° vs. - 1.15 ± 4.75°, P < 0.001; 0.43 ± 4.39° vs. - 4.27 ± 6.42°, P < 0.001) were significantly different from the predicted values in the two groups (first molar, second molar). Significant regression relationships were found between the achieved distal movement and deviational intrusion (R = 0.203, P < 0.0001), distal tip (R = 0.133, P < 0.001) and crown buccal torque (R = 0.067, P < 0.05). There was a significant correlation between the deviational movements of intrusion and the distal tip (R = 0.555, P < 0.0001).
CONCLUSION
Approximately 2 mm maxillary molar distalization was achieved in this study. Deviational movement of intrusion, distal tip and crown buccal torque beyond the clear aligner virtual design appeared to a certain degree after distalization. Thus, more attention should be given to molar intrusion and distal tip and crown buccal torque as the designed distalization increases.
Topics: Male; Female; Humans; Torque; Malocclusion, Angle Class II; Maxilla; Molar; Crowns; Orthodontic Appliances, Removable; Tooth Movement Techniques
PubMed: 38151662
DOI: 10.1186/s40510-023-00500-4