Machine learning based orthodontic treatment planning for mixed dentition borderline cases suffering from moderate to severe crowding: An experimental research study.

BACKGROUND: Pedodontists and general practitioners may need support in planning the early orthodontic treatment of patients with mixed dentition, especially in borderline cases. The use of machine learning algorithms is required to be able to consistently make treatment decisions for such cases. OBJECTIVE: This study aimed to use machine learning algorithms to facilitate the process of deciding whether to choose serial extraction or expansion of maxillary and mandibular dental arches for early treatment of borderline patients suffering from moderate to severe crowding. METHODS: The dataset of 116 patients who were previously treated by senior orthodontists and divided into two groups according to their treatment modalities were examined. Machine Learning algorithms including Multilayer Perceptron, Linear Logistic Regression, k-nearest Neighbors, Naïve Bayes, and Random Forest were trained on this dataset. Several metrics were used for the evaluation of accuracy, precision, recall, and kappa statistic. RESULTS: The most important 12 features were determined with the feature selection algorithm. While all algorithms achieved over 90% accuracy, Random Forest yielded 95% accuracy, with high reliability values (kappa = 0.90). CONCLUSION: The employment of machine learning methods for the treatment decision with or without extraction in the early treatment of patients in the mixed dentition can be particularly useful for pedodontists and general practitioners.

Early extractions of premolars reduce age-related crowding of lower incisors: 50 years of follow-up.

OBJECTIVES: To study the effects of extraction of four premolars, without subsequent orthodontic treatment, on the crowding of lower incisors in subjects between early adolescence and late adulthood, as compared to untreated subjects. MATERIALS AND METHODS: A total of 45 subjects were included in this study. The extraction group comprised 24 subjects who had all the first premolars removed at a mean age of 11.5 years, to relieve crowding in a class I malocclusion without subsequent orthodontic treatment. The control group had 21 untreated subjects, having a normal occlusion at a mean age of 13.0 years. The participants were documented with dental casts and cephalograms at mean ages of 11.4 and 13.0 years, for the two groups respectively (T1), and at mean ages of 30.9 years (T2) and 61.7 years (T3). Changes in lower incisor crowding were described as changes in "irregularity" and "space deficiency." RESULTS: The extraction group showed no changes in the irregularity of the lower incisors and significant improvement of the space deficiency of the lower teeth into late adulthood. While in the control group, both irregularity of the lower incisors and space deficiency of the lower teeth increased significantly into late adulthood. CONCLUSION: Lower incisor alignment remains mainly unchanged into late adulthood in subjects who have all their first premolars removed in childhood, as the only treatment to relieve teeth crowding. CLINICAL RELEVANCE: Severe crowding in a class I occlusion can be solved solely with premolar extraction, allowing for spontaneous adjustments with more stable incisor alignment up to late adulthood.

Mandibular dental changes following serial and late extraction of mandibular second premolars.

OBJECTIVES: To determine changes in occlusal curves and dental tipping occurring from mandibular second premolar serial extraction, early extraction of deciduous mandibular second molars with missing second premolars, and late second premolar extraction compared with untreated controls. MATERIALS AND METHODS: Information was collected from 85 subjects at three time points: T0, prior to serial extraction; T1, after serial extraction and drift prior to orthodontic treatment, and pretreatment for the late premolar extraction patients; and T2, posttreatment. Untreated age- and gender-matched controls were used for comparison. Three occlusal curves were measured on digitized mandibular casts, and dental tipping was assessed using lateral cephalograms. RESULTS: At T0, there were no significant differences among groups. At T1, there was significant steepening of Monson's sphere and the curve of Wilson between early and late extraction and control groups. At T2, the differences in Monson's sphere and the curve of Wilson were fully corrected. At T1, there were significant differences in the tipping of mandibular 6's, 4's, and 3's between the early extraction groups compared with the late extraction and control groups. At T2, these differences in tipping were fully corrected. There were no differences in mandibular incisor tipping between groups at T1 or T2. CONCLUSIONS: Serial extraction produced steeper occlusal curves and significant tipping of mandibular first molars, first premolars, and canines after extraction and physiologic drift (T1). Accentuated occlusal curves and tooth tipping were fully corrected following orthodontic treatment (T2). Mandibular incisor position was unchanged by serial or late second premolar extraction.

Strategic serial extractions and immediate implantation for interdental papilla preservation: A case report / 대한치과보철학회지

Maintaining the blood supply of the interdental alveolar bone is crucial for preserving the interdental papilla. Rebuilding the interimplant papilla between adjacent implants is more difficult than rebuilding the interdental papilla between the natural tooth and implant. Therefore, preserving the interimplant tissue is necessary when adjacent implants are closely placed. In this case report, three effective methods for maintaining the surrounding tissue, namely strategic serial extraction, immediate implantation, and provisionalization of adjacent maxillary central incisors, were performed. The marginal gingiva and interimplant papilla were well maintained for 24 months.

Modified serial extraction treatment in a patient with congenitally missing lower second premolars.

Serial extraction is a sequential plan of premature removal of one or more deciduous teeth in order to improve the alignment of permanent teeth and then removal of permanent teeth to maintain the proper ratio between tooth size and arch size. The aim of this case report was to present a case treated successfully with a modified serial extraction protocol in the lower arch because the patient had congenitally missing lower second premolars with severe crowding. The treatment consisted of selective removal of the deciduous mandibular teeth only (C, D, and E) and no permanent premolar removal. However, the space of the missing second premolars was utilized to resolve the anterior crowding along with the spontaneous closure of the extra spaces by physiologic movement of the permanent mandibular teeth. Whereas in the upper arch conventional serial extraction was performed.

Early vs late orthodontic treatment of tooth crowding by first premolar extraction: A systematic review.

OBJECTIVE: To investigate the body of evidence in the literature about the most favorable time for initiating orthodontic treatment in patients with severe crowding caused by tooth size arch length deficiency (TSALD). MATERIALS AND METHODS: Electronic databases (PubMed, Ovid Medline, Scopus, Virtual Health Library, and The Cochrane Library) were searched for articles published between 1900 and April 2014. Studies were included that evaluated treatment of patients with severe crowding caused TSALD, who were treated with first premolar extraction. The association between the stage of development of occlusion at which treatment was started, and the primary and/or secondary outcomes of early and late treatment were investigated. RESULTS: After application of the eligibility criteria and reading of the full texts, six articles were included in the final review. Of these six articles, all of which were retrospective, four showed that the primary outcome (correction of severe crowding) of the early and late groups was improved, but without statistically significant differences after treatment. Therefore, the findings of secondary outcomes in the literature (postretention crowding relapse, duration of total and active treatment [treatment with appliances], external apical root resorption, and soft tissue profile) were the target of this study. These studies presented low or moderate methodological quality and control of bias. CONCLUSIONS: Both early and late extraction had a similar effect on correction of crowding. Early treatment had two favorable secondary outcomes (less relapse and reduced active treatment time) vs late treatment. However, the levels of evidence were not sufficient to assert which protocol was superior.

Beneficios de la Implementación de Ortodoncia Interceptiva en la Clínica Infantil / Benefits of the Implementation of Interceptive Orthodontic in Pediatric Dental Clinic

El objetivo fue determinar el beneficio de implementar acciones clínicas de ortodoncia interceptiva en paciente infantiles analizando la literatura reciente. Se realizó una revisión sistemática de la literatura mediante una búsqueda en Pubmed, SciELO y Cochrane Library de los últimos 10 años respondiendo a la pregunta: "¿En niños con maloclusiones dentoalveolares es beneficiosa la implementación de ortodoncia interceptiva o es mejor una terapia al término del crecimiento?". Las palabras de búsqueda fueron "orthodontic interceptive", "serial extraction" o sus traducciones en español. Se utilizaron criterios de inclusión y exclusión para obtener evidencia del más alto nivel. Se seleccionaron 17 artículos de los cuales, cinco fueron ensayos clínicos, seis de cohorte retrospectiva, cuatro revisiones sistemáticas y un caso clínico de larga data. La mayoría de los reportes utilizan los índices de maloclusión ICON y PAR para realizar las mediciones pre y post-tratamiento y evaluar efectividad del uso de la ortodoncia interceptiva. La extracción de caninos temporales por si sola no previene la impactación de caninos permanentes. La extracción seriada tuvo un tiempo de control sin aparatos más largo, pero menor periodo de tratamiento activo y se indica en pacientes con más de 6 mm de discrepancia negativa dentomaxilar. La mayoría de los estudios muestra un alto nivel de evidencia (53%), pero presentan diferencias en las variables estudiadas y en las modalidades de tratamientos que no los hacen comparables entre ellos. Hay evidencia de que la intervención temprana en niños con maloclusiones dentoalveolares es beneficiosa, mejoran resalte y la alineación anterior maxilar y mandibular. La discrepancia dentomaxilar severa es factible de tratar con extracción seriada. La evidencia es escasa para mordida abierta y malos hábitos. El tratamiento interceptivo requiere largo seguimiento y no elimina la necesidad de tratamiento correctivo. No existe evidencia de que la resolución interceptiva de la mordida cruzada sea positiva.

The aim was to determine the benefit of implementing interceptive orthodontic clinics in infant patient analyzing recent literature about it. We conducted a systematic review of the literature by searching PubMed, SciELO and Cochrane Library for the past 10 years in response to the question: "In children with dentoalveolar malocclusions is it beneficial to implement interceptive orthodontics or is it better to apply a therapy at the end of growth?" Searching words were "interceptive orthodontic", "serial extraction" or its translations in Spanish. We used inclusion and exclusion criteria to find the highest-level evidence. We selected 17 items of which five were clinical trials, six were retrospective cohort, and four were systematic reviews and one clinical case of long standing. Most reports use ICON and PAR index malocclusion for pre and post-treatment and to evaluate the effectiveness of using interceptive orthodontics. Cuspid extraction alone does not prevent permanent canine impaction. The control of serial extraction without braces was longer than with braces, but the active treatment period was shorter. This process is indicated in patients with more than 6 mm dentomaxilar negative discrepancy. Most studies show a high level of evidence (53%), but they differ in some variables and some treatments modalities, which do not make them comparable. There is evidence that early intervention in children with dentoalveolar malocclusions is beneficial, improving over-jet and alignment of anterior maxillary and mandibular. It is feasible to treat severe dentomaxilar discrepancy with serial extraction. The evidence is insufficient to open bite and bad habits. Interceptive treatment requires lengthy follow up and does not eliminate the need for corrective treatment. There is no evidence that the resolution interceptive crossbite is positive.

Serial extraction: 20 years of follow-up

This paper reports a case treated by a serial extraction program at the mixed dentition stage followed by a corrective orthodontic treatment, with a long-term follow-up period. Twenty years after the interceptive treatment, a harmonious face was observed along with treatment stability in the anterior posterior direction, deep overbite (which has been mentioned as a disadvantage of the serial extraction program), and a small relapse of anterior tooth crowding. All these conditions have been regarded as normal occurrences for most orthodontic treatments with a long-term follow-up period. This case report demonstrated that the establishment of a serial extraction protocol determined relevant esthetic changes that afforded an improvement of the patient's self-esteem, with a positive social impact. Furthermore, the low cost of this protocol permits the use of this therapy with underprivileged populations. It is important to emphasize that an early correction of tooth crowding by this protocol does not guarantee stability, but small relapses do not invalidate its accomplishment.

Programa de extrações seriadas: variáveis relacionadas com a extração de pré-molares / Serial extraction: variables associated to the extraction of premolars

OBJETIVO: verificar o percentual de pacientes que necessitaram extração de dentes permanentes, pré-molares, dentre aqueles tratados com extração de dentes decíduos para correção do apinhamento primário na dentição mista, bem como analisar as possíveis variáveis relacionadas. MÉTODOS: a amostra foi composta por documentações ortodônticas de 70 pacientes na dentição permanente, cujo tratamento iniciou-se na dentição mista com planejamento de um programa de extrações seriadas (PES). Todos os prontuários foram analisados por um único examinador, no intuito de verificar se o PES havia sido cumprido com a extração de dentes permanentes ou se havia sido realizada apenas extração de dentes decíduos. Verificou-se a associação entre a extração de dentes permanentes e as variáveis padrão facial; relação sagital entre as arcadas dentárias; IMPA; proporção tamanho do segundo molar permanente inferior/espaço retromolar; mecânica de controle de espaço e discrepância de modelo (teste exato de Fisher para as variáveis categóricas e modelo de regressão logística para as variáveis numéricas). Os resultados foram considerados para p<0,05. RESULTADOS: dos pacientes que haviam sido tratados com extração de dentes decíduos para a correção do apinhamento na dentição mista, 70 por cento necessitaram de extração de dentes permanentes. A análise estatística não mostrou associação significativa entre as variáveis estudadas e a necessidade de extração de dentes permanentes, com exceção da variável discrepância de modelo. CONCLUSÃO: a discrepância de modelo representou a principal determinante de extração de pré-molares no PES.

OBJECTIVE: To determine the frequency of patients who require extraction of permanent premolars among those treated with extraction of deciduous teeth for the correction of incisor crowding in the mixed dentition and analyze possible associated variables.METHODS: The sample was composed of orthodontic records of 70 patients with permanent dentition whose treatment had begun in the mixed dentition phase and involved serial extraction. All records were analyzed by a single examiner to determine whether serial extraction had been performed with extraction of permanent teeth or only deciduous teeth. Associations were investigated between extraction of permanent teeth and lateral facial pattern, sagittal relationship of the dental arches, incisor-mandibular plane angle, size proportion of mandibular second molar/retromolar space, mechanics for space control and tooth-arch size discrepancy (Fisher's exact test for categorical variables and logistic regression for numeric variables, p<0.05).RESULTS: Among the patients who had been treated with extraction of deciduous teeth, 70% required the extraction of permanent teeth. The statistical analysis revealed no significant associations between the analyzed variables and the need for permanent tooth extraction, with the exception of tooth-arch size discrepancy.CONCLUSION: Tooth-arch size discrepancy was the main factor determining premolar extraction in a serial extraction program.