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Premolar extraction is 1 option for treatment of patients with malocclusion and severe crowding or protrusion. When the patient has missing or hopeless teeth other than premolars, it is possible to consider removal of those teeth to use the space to decrease crowding. A 15-year-old girl sought treatment for severe crowding. She had already lost her maxillary right first premolar as a result of caries 1 year previously and had a hopeless maxillary right central incisor. Her mandibular left first molar still caused discomfort even after endodontic treatment. Extractions of the maxillary right central incisor and mandibular right first premolar and left first molar were chosen to resolve the occlusion problems. Orthodontic mini-implants were placed to translocate the maxillary left central incisor across the midpalatal suture to use the space in the maxillary right quadrant to relieve the crowding. Although a different extraction option was used in each quadrant, the final occlusion was acceptable. After debonding, porcelain crowns were placed on the anterior teeth to improve esthetics. The treatment result remained stable after 2 years of retention.

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BACKGROUND: Potentization, consisting of serial dilution and succussion, is a key step in the manufacture of homeopathic medicines. Originally prescribed as a manual process, several attempts at mechanization have been published, patented and even commercialised in order to remove the human element and introduce reproducibility without drudgery. Various machines have been used over the years to prepare homeopathic medicines. Although these machines follow the same principles, i.e. energetically mixing the medicines and diluting them significantly, their mode of operation is different from each other. METHODS: This review paper surveys the main methods of preparation of homeopathic medicines. The main machines discussed are: Boericke's potentizer, Tyler Kent's instrument, John Alphonse's machine and the fluxion potentizer, which were used in the past, as well as more recent potentizers like arm-and-weight instruments, the K-Tronic potentizer and Quinn's machine. We review the construction and operating principle of each of these machines, along with their advantages and limitations. A scheme for relative performance assessment of these machines is proposed based on the parameters mechanical efficiency, physico-chemical efficiency, turbulence generation, energy dissipation, and accuracy of dilution. RESULTS: Quinn's machine and the arm-and-weight potentizer perform well for generating turbulence due to high impaction forces, while John Alphonse's machine is much more accurate in diluting the homeopathic medicines at every step. CONCLUSIONS: Both the commercial potentizers, Quinn's machine and the K-Tronic potentizer, are completely automated and therefore reduce the manual labour and variation in succussive forces during each step, which may produce uniformity in physico-chemical changes within the resulting homeopathic medicines.

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INTRODUCTION: Variations in treatment times for serial extraction and late premolar extraction patients may be due to differences in the time needed to flatten the occlusal curves. In this study, we compared tooth tipping and occlusal curves in patients treated by serial extractions or late premolar extractions with untreated controls. METHODS: Mandibular dental casts and cephalometric radiographs were collected from 90 subjects (30 Class I control subjects, 30 patients with serial extractions, and 30 with late premolar extractions) at 3 time points: T0, baseline for the controls and serial extraction patients; T1, after natural drift and preorthodontics for the controls and the serial extraction patients, and pretreatment for the late premolar extraction patients; and T2, after comprehensive orthodontic treatment for the serial extraction and the late premolar extraction groups. The long axes of the central incisor, canine, and first molar to the palatal plane were measured on digitized headfilms to determine the direction and the amount of tipping between the time points. Three occlusal curves were measured by sphere fitting cusp-tip landmarks on digitized mandibular casts. RESULTS: From T0 to T1, incisors and canines in the patients with serial extractions tipped distally. Molars at T1 in the patients with serial extractions were tipped forward more than in the late premolar extraction patients and the controls. From T1 to T2, canines and molars in the patients with serial extractions were uprighted. CONCLUSIONS: Serial extractions produce steeper occlusal curves and distal tipping of the incisors and canines after drift (T1). Posttreatment (T2) occlusal curves in the patients with serial extractions are steeper than in the late premolar extraction patients and controls (except for the curve of Spee). After the serial extractions, orthodontic treatment included incisor and canine proclination, with molar uprighting and occlusal curve flattening.

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Four premolar extractions is a successful protocol to treat Class I malocclusion, but it is a less efficient way when compared with other Class II treatment protocols. Objective: The objective of this study was to evaluate the influence of anteroposterior discrepancy on the success of four premolar extractions protocol. For that, treatment efficiency of Class I and complete Class II malocclusions, treated with four premolar extractions were compared. Methods: A sample of 107 records from 75 Class I (mean age of 13.98 years - group 1) and 32 Class II (mean age of 13.19 years - group 2) malocclusion patients treated with four premolar extractions was selected. The initial and final occlusal status of each patient was evaluated on dental casts with the PAR index. The treatment time was calculated based on the clinical charts, and the treatment efficiency was obtained by the ratio between the percentage of PAR reduction and treatment time. The PAR index and its components, the treatment time and the treatment efficiency of the groups were statistically compared with t tests and Mann-Whitney U-test. Results: The Class II malocclusion patients had a greater final PAR index than Class I malocclusion patients, and similar duration (Class I - 28.95 mo. and Class II - 28.10 mo.) and treatment efficiency. Conclusion: The treatment of the complete Class II malocclusion with four premolar extractions presented worse occlusal results than Class I malocclusion owing to incomplete molar relationship correction. .

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UNLABELLED: Four premolar extractions is a successful protocol to treat Class I malocclusion, but it is a less efficient way when compared with other Class II treatment protocols. OBJECTIVE: The objective of this study was to evaluate the influence of anteroposterior discrepancy on the success of four premolar extractions protocol. For that, treatment efficiency of Class I and complete Class II malocclusions, treated with four premolar extractions were compared. METHODS: A sample of 107 records from 75 Class I (mean age of 13.98 years--group 1) and 32 Class II (mean age of 13.19 years--group 2) malocclusion patients treated with four premolar extractions was selected. The initial and final occlusal status of each patient was evaluated on dental casts with the PAR index. The treatment time was calculated based on the clinical charts, and the treatment efficiency was obtained by the ratio between the percentage of PAR reduction and treatment time. The PAR index and its components, the treatment time and the treatment efficiency of the groups were statistically compared with t tests and Mann-Whitney U-test. RESULTS: The Class II malocclusion patients had a greater final PAR index than Class I malocclusion patients, and similar duration (Class I - 28.95 mo. and Class II - 28.10 mo.) and treatment efficiency. CONCLUSION: The treatment of the complete Class II malocclusion with four premolar extractions presented worse occlusal results than Class I malocclusion owing to incomplete molar relationship correction.

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This article discusses a case of an 8-year-old female child who presented with severe lower anterior crowding and congenitally missing lower second premolars. A conventional serial extraction procedure could not be performed due to the congenital absence of teeth. Instead, planned extraction of a few primary teeth was done to relieve the lower anterior crowding, the results of which were near satisfactory.

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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.

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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.

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Dentro del campo del tratamiento ortodoncico en dentición mixta, la exodoncia seriada ocupa una parcela de gran importancia. Quizás con el paso del tiempo esta terapia no tiene la vigencia que su eficiencia conlleva. Las situaciones que suponen una alteración en la secuencia eruptiva normal, -debidas fundamentalmente a la falta severa de espacio disponible en la arcada dentaria,- son su indicación preferente. Este procedimiento, mediante un manejo sencillo pero correctamente indicado, solventa estas alteraciones que pueden modificar o impedir el recambio dentario. En estos dos trabajos se intenta analizar cuales son los condicionantes, indicaciones y mecánicas a seguir, además de establecer los criterios terapéuticos para su realización (AU)

Regarding orthodontic treatment in the mixed dentition, serial extraction has an important role. This clinical approach is not used as frequent as it should be, considering the efficiency behind the procedure. The main indication for this technique is an alteration of normal eruption sequence caused by a severe arch-length-tooth-size discrepancy. This procedure, through an easy clinical management, can help tooth eruption disturbances. In this second-part series, the authors will establish the diagnostic criteria for the clinical management of serial extraction in orthodontic practice (AU)

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INTRODUCTION: This retrospective study was designed to investigate the position changes and movement patterns of incisors and molars after orthodontic treatment with extractions of 4 second premolars in patients with mild crowding, slight dental protrusion, and Angle Class I relationship. METHODS: Pretreatment and posttreatment cephalograms of 26 subjects were chosen from patients treated by an experienced orthodontist. The movements of the incisors and the molars as well as tooth tipping were measured. RESULTS: Relative to the posttreatment occlusal plane, the mean incisor movements were 3.3 and 2.9 mm lingually in the maxilla and the mandible, respectively. The first molars were moved mesially an average of 3.2 and 3.4 mm in the maxilla and the mandible, respectively. The incisor inclination was under proper control. The extraction space was almost equally taken up by the anterior and posterior segments. CONCLUSIONS: These data can be used to estimate the expected position changes and movement patterns of the incisors and molars in patients with mild crowding and slight bialveolar dental protrusion after orthodontic treatment with 4 second premolar extractions.

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Dentro del campo del tratamiento ortodóncico en dentición mixta, la exodoncia seriada ocupa una parcela de gran importancia. Quizás con el paso del tiempo esta terapia no tiene la vigencia que su eficiencia conlleva. Las situaciones que suponen una alteración en la secuencia eruptiva normal, -debidas fundamentalmente a la falta severa de espacio disponible en la arcada dentaria,- son su indicación preferente. Este procedimiento, mediante un manejo sencillo pero correctamente indicado, solventa estas alteraciones que pueden modificar o impedir el recambio dentario. En estos dos trabajos se intenta analizar cuáles son los condicionantes, indicaciones y mecánicas a seguir, además de establecer los criterios terapéuticos para su realización (AU)

Regarding orthodontic treatment in mixed dentititon, serial extraction has play an important role. Actually it has a less relevant paper with a certain unknown about its efficiency. Alteration of the normal eruption, due mainly to lack of space is the prefered indication. lt is a relative simple procedure if indication had been stablished in the right way. In two papers, we will try to analyze the factors involved in the indications and procedures and concluding with treatment criteria (AU)

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AIM: The purpose of this article is to show the value of serial extractions in a young patient with severe crowding. BACKGROUND: Serial extraction is a technique advocated for use by Kjellgren in 1948 due to a shortage of orthodontists at the time. This form of treatment was intended to facilitate the treatment of orthodontic cases by general dentists to minimize the demand upon the orthodontist. CASE DESCRIPTION: An eight-year-old Sudanese female did not like the appearance of her anterior teeth. Clinical examination revealed a Class I molar relationship, severe crowding of the maxillary and mandibular arches, minimum overjet, and minimum overbite. RESULTS: The patient's treatment included serial extractions. The treatment resulted in improved esthetics, good arch alignment, and occlusion while maintaining her Class I molar relationship, overjet, and overbite. SUMMARY: This case demonstrated that despite the criticism some may direct toward this interceptive technique, good clinical results can be achieved in carefully selected cases. CLINICAL SIGNIFICANCE: There are certain clinical situations when treatment planning the use of serial extractions can prove beneficial to young patients.

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INTRODUCTION: The purpose of this study was to investigate the effects of premolar extractions on the Bolton overall ratios and overall tooth-size discrepancies in a Japanese orthodontic population. METHODS: Mesiodistal tooth widths were measured on 198 pretreatment dental casts of subjects with Class I, Class II, and Class III malocclusions. The overall ratios and tooth-size discrepancies were determined before and after hypothetical premolar extractions. Before and after extractions, the subjects were divided into small, normal, and large overall ratio groups categorized by the Bolton standard deviation definition, and into small, normal, and large correction groups by the actual amount of change calculated for tooth-size correction in millimeters. Extractions were performed in the following combinations: (1) all first premolars, (2) all second premolars, (3) maxillary first and mandibular second premolars, and (4) maxillary second and mandibular first premolars. For statistical evaluations, analysis of variance, Kruskal-Wallis, Friedman, Scheffé, Bonferroni, and Tukey tests were performed. RESULTS: The overall ratios decreased in every malocclusion group after extraction of any combination of premolars. The decreases were significantly notable in combinations 2 and 4. Some subjects in the normal overall ratio and maxillary and mandibular correction groups moved into the clinically significant tooth-size discrepancy group after premolar extraction, and the reverse was also true. CONCLUSIONS: In formulating a treatment plan involving premolar extractions, orthodontists should consider that the overall ratios might decrease, and normal and clinically significant tooth-size discrepancies could change mutually after extractions.

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OBJECTIVE: To quantify the amount of perioral tissue changes following the extraction of four premolars in patients with bimaxillary protrusion who had nearly completed active growth. MATERIALS AND METHODS: A literature search was conducted to identify clinical trials that assessed cephalometric perioral soft tissue changes in patients affected by biprotrusion and treated with extractions. Electronic databases (PubMed, ISI WoS Science Citation Index Expanded, and HubMed) were searched. Abstracts that appeared to fulfill the initial selection criteria were selected, and the full-text original articles were retrieved and analyzed. Only articles that fulfilled the final selection criteria were finally considered. Their references were also hand-searched for possible missing articles from the database searches. RESULTS: Nine abstracts met the initial inclusion criteria and these articles were retrieved. From these, five were later rejected mostly because the sample dealt with growing subjects. Four articles remained and they showed that the upper and lower lips retracted and the nasolabial angle increased following premolar extraction. Upper lip retraction ranged from 2 mm to 3.2 mm, lower lip retraction ranged from 2 mm to 4.5 mm. CONCLUSIONS: The lip procumbency improves following the extraction of four premolars and this improvement is predictable. However, the changes are small and do not dramatically modify the profile. A "dished in" profile is not to be expected. Individual variation in response is large.

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El propósito de este trabajo es exponer una terapéutica para corregir retenciones dentarias por métodos ortodónticos, eligiendo la extracción de segundos molares permanentes como recurso principal en la obtención del espacio necesario en la arcada dentaria. Se presentan dos casos clínicos que si bien ofrecen diferencias en cuanto al tipo de retención, fueron tratados de la misma forma: distalamiento con extracción de segundos molares superiores y posterior ubicación ortodóncica de las piezas retenidas. Asimismo, se hace hincapié en los cuidados a tener en la técnica quirúrgica para abordar dientes retenidos, cuando nuestro objetivo es conservarlos y no extraerlos.(AU)

The main purpose of this work is to describe a treatment that involves distal movement and second molars extraction in order to get enough space for impacted teeth. Two clinical cases are shown.(AU)

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El propósito de este trabajo es exponer una terapéutica para corregir retenciones dentarias por métodos ortodónticos, eligiendo la extracción de segundos molares permanentes como recurso principal en la obtención del espacio necesario en la arcada dentaria. Se presentan dos casos clínicos que si bien ofrecen diferencias en cuanto al tipo de retención, fueron tratados de la misma forma: distalamiento con extracción de segundos molares superiores y posterior ubicación ortodóncica de las piezas retenidas. Asimismo, se hace hincapié en los cuidados a tener en la técnica quirúrgica para abordar dientes retenidos, cuando nuestro objetivo es conservarlos y no extraerlos.

The main purpose of this work is to describe a treatment that involves distal movement and second molars extraction in order to get enough space for impacted teeth. Two clinical cases are shown.

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Chemical and spectroscopic analyses ((13)C cross-polarization-magic angle spinning NMR and attenuated total reflection Fourier transform infrared spectroscopies) were carried out on the wood of Vitis vinifera cv. Sangiovese with brown-red discoloration and black streaks caused by esca disease. The analyses of the brown-red wood revealed the destruction of hemicelluloses and noncrystalline cellulose as well as modifications in the pectic and ligninic wood fractions. The pectic fraction consisted of carbohydrates associated with polyphenols. The lignin fraction exhibited only a few changes in the aromatic systems and a partial demethylation, and it appeared to be associated with condensed phenolic components probably arising from response polyphenols. The degradation of hemicelluloses and noncrystalline cellulose in brown-red wood, where the pathogens Phaeoacremonium aleophilum and Phaeomoniella chlamydospora prevail with respect to the other fungus Fomitiporia mediterranea, was consistent with reports on the degradative activity of such fungi in vitro carried out on model substrates. The observed alterations could also be attributed to the radical oxidation process caused by the oxidative response of defense itself triggered by infection, as suggested by the accumulation of postinfectional compounds. The analyses of wood tissue with black streaks showed less marked deterioration; here, an increase in pectic and phenolic substances, which probably accumulate in the xylem vessels as a response to the infection, was observed.

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BACKGROUND: Conversion of a hopeless dentition to a full-arch reconstruction can be a difficult period for patients if they have to wear a denture. A serial extraction protocol can help to avoid this dilemma. RESULTS: Protocols for serial extraction of teeth are presented. This methodology avoids having patients wear a denture while converting from a hopeless dentition to a full-arch reconstruction supported by dental implants. Treatment planning with regard to placing all implants in one round of implantation vs two or more rounds of implantation is reviewed. In addition, strategies to simplify treatment regimens are discussed. CLINICAL IMPLICATIONS: The presented protocols facilitate transitioning patients from a destroyed dentition to a full-arch reconstruction. These protocols also can be used for a segment of an arch.

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This study assessed the effect of extraction and preservation of the 1st premolar on lower 3rd molar eruption. Orthodontic clinic records from 1993 to 1995 were evaluated before and after treatment and 8-9 years after treatment for 3 groups of patients: 32 with extraction of 1st premolars in both jaws, 32 with no extraction but orthodontic treatment and 48 controls with no extraction but orthodontic treatment in the upper jaws only. Successful eruption of 3rd molars was evaluated. There was a significant difference in the rates of successful eruptions in the extraction (42%), non-extraction (12%) and control (20%) groups. The findings indicate that 1st premolar extraction may increase the chance of 3rd molar eruption, leading to a lower incidence of health and economic complications.

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Este reporte de caso muestra una paciente con clase II esqueletal y una simetría condilar compatible con una reabsorción condilar progresiva unilateral, tratada según el protocolo de planificación de Arnett, con ortodoncia y cirugía ortognática.

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