Extraction Of Lower Premolars Research Articles

Effect of orthodontic extraction of mandibular premolars on third molar angulation after treatment with fixed appliances : Across-sectional study.

Orthodontic treatment involving premolar extractions might improve the angulation of lower third molars, which are the teeth most often impacted. This study analyzes the impact of first/second lower premolar extraction during orthodontic therapy on the angulation of mandibular third molars. A total of 120patients treated non-extraction (n = 40), with extraction of first (n = 40), or second lower premolars (n = 40) were included. The mesiodistal angulation of lower third molars relative to the adjacent tooth and their developmental stage were evaluated from posttreatment orthopantomograms. Between-group differences were statistically evaluated at asignificance level of 0.05. The orthopantomograms of 120patients (51% female) with amedian age of 15.2years at the time of debonding were evaluated after amean treatment duration time of 2.9years. No difference (P > 0.05) was seen between the average angulation of the lower third molars of the right (mean = 24.4°, standard deviation [SD] 13.6°) and the left side (mean = 23.6°, SD 14.1°). No differences in the angulation of the lower third molar were found between the non-extraction and extraction groups for the right (P = 0.44) or the left side (P = 0.22). Likewise, no differences were found when comparing the first and second premolars for the right (P = 0.26) or the left side (P = 0.10). Premolar extraction was associated with an advanced root development stage of the right third molar (odds ratio 7.1; 95% confidence interval 1.1-48.1; P = 0.04), with no differences between extraction of the first or second premolar (P = 0.10). Orthodontic treatment involving premolars extractions might be associated with asmall acceleration in root development, but not with the angulation, of lower third molars.

Orthodontic Camouflage of Borderline Skeletal Class III MalocclusionA Report of Two Cases

Camouflage treatment in borderline Class III patients, especially those who refuse a surgical line of treatment, remains a challenge to the orthodontists. Such patients were usually treated using Class III elastics and lower premolar extractions. Mandibular arch distalisation is an alternative option for non extraction Class III camouflage. Temporary Anchorage Devices (TADs) help in achieving effective mandibular molar distalisation and are more accepted by adult patients. This case report discusses the diagnosis and management of two different presentations of borderline skeletal Class III malocclusion treated with miniscrew assisted mandibular arch distalisation. Two adult female patients between 18-20 years of age presented with a skeletal Class III malocclusion, average growth pattern, super Class I molar relationship and straight facial profile. The patients did not agree for a surgical line of treatment. Camouflage treatment by distalisation of mandibular arch using buccal miniscrew implants was done. Inter-radicular miniscrews were placed between mandibular second premolar and first molar to apply distalisation force of 250 gm/side. Lower arch distalisation of 2-3 mm was achieved in an average of 4.6 months. The outcomes were well retained 3 years post-treatment.

Correction of Severe Skeletal Class II High Angle with Mandibular Retrusion and Gummy Smile by Double-Jaw Surgery.

This report describes the treatment of severe skeletal Class II malocclusion in a young woman with a gummy smile and pronounced lower anterior facial height. Overjet and overbite were +12.0 mm and -1.0 mm, respectively. Cephalometric analysis revealed inferior positioning of the maxilla and severe mandibular retrusion with clockwise rotation. Both the upper and lower anterior teeth showed labial inclination. Based on a diagnosis of a skeletal Class II high angle with mandibular retrusion and a gummy smile, double-jaw orthognathic surgeries for upper and lower premolar extraction were chosen to gain ideal occlusion and an improvement in the esthetic facial profile. Le Fort I osteotomy was performed to move the anterior and posterior teeth upward by 4.0 mm and achieve mandibular counterclockwise rotation. Short lingual sagittal split ramus osteotomy was performed to move the mandible forward by 3.0 mm. As a result, normal overjet and overbite were achieved together with a straight profile and a good smile. After surgery, electromyographic evaluation of anterior temporal muscle activity showed an improvement in the percentage overlapping coefficient value (a symmetric index of bilateral muscle activity) from 28.1% to 63.2% compared to at pre-treatment. The pattern of jaw movement also showed an improvement. These results suggest that orthognathic surgery in skeletal Class II cases can improve not only malocclusion and the skeletal relationship of the jaws, but also masticatory function and jaw movement.

Effects of Soft Tissue Closure on Medication-Related Osteonecrosis of the Jaw in a Rabbit Model with Tooth Extraction: A Pilot Study

Objectives The study investigated the effect of soft tissue closure after tooth extraction on the prevention of medication-related osteonecrosis of the jaw in a rabbit model. Materials and Methods Twenty female New Zealand white rabbits were randomly assigned into the experimental group administrated with zoledronic acid (ZA) and control groups treated with saline. Bilateral lower premolar extraction was performed 4 weeks after ZA/saline administration. Immediately after extraction, the wound on the right mandible was closed by suture while the other side was left open. Animals were sacrificed 4 weeks and 8 weeks after tooth extraction. Fluorochrome labeling solutions were injected subcutaneously to evaluate the bone growth rates. The mandibles were harvested and subjected for microcomputed tomography, confocal microscope, and histomorphological examinations. Results All extraction sites healed well without any signs of infection. Trabecular thickness (Tb.Th) was significantly higher in the ZA-treated group than in the control group at both week 4 and week 8, while no significant difference was detected in the rest of the assessed parameters. The bone growth rate in mandibles showed gradual reduction in the ZA-treated group. Histological analysis showed that at week 8, the animals in the ZA-treated group had significantly higher incidence of osteonecrosis than that in the control group, while no significance was revealed between the sutured and nonsutured side. Conclusions ZA treatment significantly reduces bone growth rates but does not reveal a significant effect on bone mineral density and bone microarchitecture. Soft tissue closure of the extraction socket does not reduce the incidence of ONJ in the ZA-treated rabbit model.

Retreatment of an orthognathic camouflaged case by total lower arch mesialization using temporary anchorage device

Mandibular tooth extractions for camouflage treatments in borderline Class III patients may end up with unpleasing esthetic results which may lead the patient seeking further complicated retreatments. In this case report, we presented a patient's retreatment with a combined orthodontic and orthognathic surgery treatment plan. The treatment strategy involved an innovative temporary anchorage device (TAD)-based method for total mandibular arch mesialization instead of space reopening for first lower premolar replacement with implants. In the current case report, orthognathic management of a Class III adult female is discussed. The patient had a history of an esthetically unsuccessful previous camouflaged orthodontic treatment with two lower premolar extractions. She was prepared for orthognathic surgery using an innovative custom-made sliding jig based on miniscrews for total mandibular arch mesialization with the aim of dental arch decompensation. After gaining the optimal dental arch discrepancy, the patient had orthognathic surgery (maxillary advancement and mandibular setback and advancement genioplasty). Total mandibular dental arch mesialization with the aim of dental arch discrepancy preparation was successfully conducted using TADs. By means of the innovative miniscrew-anchored sliding jig, the patient's satisfactory esthetic and occlusal results were obtained in 22 months. With innovative application of the miniscrews, more practical and reasonable alternatives are available to replace conventional and complicated treatment plans such as space reopening for implants in patients with unsuccessful previous orthodontic therapies.

A Novel Approach to Correction of Class II Malocclusion with Lower Premolar Extractions

A Novel Approach to Correction of Class II Malocclusion with Lower Premolar Extractions

Influence of different surgical concepts for moderate skeletal class II and III treatment on the nasopharyngeal airway space

PurposeThis study aimed to compare the effects of different orthognathic and camouflage treatments for correcting moderate skeletal class II and III malocclusions on the pharyngeal airway space (PAS). Materials and methodsLateral cephalograms of 89 patients with moderate skeletal class II and III malocclusion (WITS up to 7 mm, −7 mm respectively) were evaluated before and after treatment. PAS was divided into 6 levels (P1: nasopharynx, P2-4: oropharynx, P5-6: laryngopharynx), and 7 groups were formed depending on the type of treatment: 1) class II, mandibular advancement; 2) class II, maxillary setback/mandibular advancement; 3) class II, upper premolar extraction; 4) class III, mandibular setback; 5) class III, maxillary advancement; 6) class III, maxillary advancement/mandibular setback; and 7) class III, lower premolar extraction. ResultsSignificant changes occurred only in patients with class II malocclusion (groups 1 and 2) before and after surgery in the nasopharyngeal and oropharyngeal space. Furthermore, significant differences between the patients with class II malocclusion were found when compared to the premolar extraction group: group 1 vs. group 3 (P3: −1.31 mm (SD 1.74 mm) vs. 0.89 mm (SD 1.79 mm); P4: −0.72 mm (SD 2.82 mm) vs. 1.42 mm (SD 2.16 mm); P ≤ 0.05), group 2 vs. group 3 (P2: 0.35 mm (SD 1.96 mm) vs. 2.28 mm (SD 1.88 mm), P3: −1.31 mm (SD 1.74 mm) vs. 0.35 mm (SD 1.96 mm), P4: −0.72 mm (SD 2.82 mm) vs. 2.84 mm (SD 2.16 mm), P ≤ 0.05). ConclusionsOrthognathic surgery in patients with moderate skeletal class II and III malocclusion seems to affect PAS only slightly. Premolar extractions for compensation (camouflage treatment) can result in a reduction of the oropharynx airway space in both types of skeletal malocclusions. Therefore, in borderline patients with presence of OSAS, orthognathic surgery should be considered.

Tratamiento de maloclusión de clase III con arco multiloop edgewise arch wire (meaw) reporte de caso clínico

En la actualidad hay diferentes formas de abordar la maloclusión de clase III,todas las formas tienen como objetivo principal solucionar la maloclusión y están encaminadas a diagnosticar y llevar al paciente a una oclusión estable,estética y sobretodo sin daño alguno a los tejidos que conforman e lsistema estomatognático. Se muestra en este artículo el manejo de la maloclusión de clase III con arcos de Multiloop Edgewise Arch Wire (MEAW)como una opción rápida, estable y de excelentes resultados para la solución de este tipo de discrepancias. La maloclusión de clase III puede ser tratada de diferentes formas como el tratamiento temprano, la compensacióndental, el camuflaje esquelético y la opción quirúrgica. La compensación dental puede ser de diferentes formas, como por ejemplo: exodoncias de premolares inferiores, torque inferior negativo y positivo superior, con ayuda de anclaje esquelético (mini tornillos) y muchas más que no se enuncian.En los casos que se involucra el perfil o la simetría facial y su origen es de características de ADF (Anomalía Dentocranéo Maxilofacial) requirieran de cirugía ortognatica para su solución, puesto que es de origen esquelético y debido a severidad es no compensable. Este articulo muestra un manejo diferente como opción de compensación de maloclusión de clase III. Es un reporte de caso clínico de un paciente del Posgrado de Ortodoncia de la Universidad Antonio Nariño de la clínica de arco recto manejado con brackets de prescripción MBT Gemini Unitek 3M slot 0.022”x0.025” los cuales se les coloca arcos de Multiloop Edgewise Arch Wire (MEAW) después de ocho meses de tratamiento, cuatro meses en alineación y nivelación y cuatro meses del uso arcos de Multiloop Edgewise Arch Wire (MEAW) lacorrección dentoalveolar se corrige gracias a la retracción canina y molar de 6mm bilateral haciendo rotar el plano de oclusión según la filosofía del tratamiento de Multiloop Edgewise Arch Wire (MEAW) obteniendo las seis llaves de la oclusión de Andrews.

Gingival recessions of lower incisors after proclination by orthodontics alone or in combination with anterior mandibular alveolar process distraction osteogenesis.

The aim of this study was to longitudinally compare periodontal conditions in consecutive patients who had orthodontic treatment with proclination of lower incisors either by orthodontics alone or in combination with anterior mandibular alveolar process distraction osteogenesis (DO). Nineteen patients had orthodontic treatment with DO, 18 with extraction of lower premolars (Ex), and 18 without extractions (Nonex). Lateral cephalograms were used to evaluate lower incisor proclination, while study casts and intraoral photographs were used to evaluate labial and lingual gingival recessions before (T1) and at an average of 4.5years (T2) after treatment. No differences in labial recessions on lower incisors were present between the patient groups despite greater lower incisor proclination in the Nonex and DO groups. The Ex group showed no new development of lingual recessions in contrast to the Nonex (eight sites; two subjects) and DO groups (seven sites; three subjects). Severe lingual recessions (increased ≥1mm) were more present in the Nonex group (five sites; two subjects) compared to the Ex group (no sites). Proclination of lower incisors of 10° or more either by orthodontic tooth movement or displacement of the whole alveolar process increased the risk of lingual gingival recessions 17 times. This was not the case with labial gingival recessions. Orthodontic or surgical proclination of lower incisors beyond a 10° limit increases the risk of inducing lingual gingival recessions. During orthodontic treatment, with or without DO, one should avoid proclining lower incisors more than 10° to decrease the risk of gingival recessions.

A study of Class III treatment: orthodontic camouflage vs orthognathic surgery

Abstract Aim To evaluate the differences in pretreatment and post-treatment characteristics of Class III patients treated with orthodontic camouflage or orthognathic surgery, and to compare the range of skeletal, dental and soft tissue changes that are likely to occur with treatment, with particular reference to the influence of extractions on the resultant incisor angulations. Method Pretreatment and post-treatment cephalograms of 31 Class III orthodontically-camouflaged patients and 36 Class III surgical patients (without genioplasty) were obtained from one specialist practice. From the surgical group, 26 pre-surgical lateral cephalograms were also obtained. Inclusion criteria for the two groups were at least three of the following: (1) an ANB angle of 1 degree or less, (2) a Wits appraisal less than -4 mm, (3) an incisal overjet ≤0 mm, and (4) a Class III molar relationship. All lateral cephalograms were traced and digitised and a number of skeletal, dental and soft tissue variables were measured. The camouflage and surgical groups were also divided into premolar extraction and non-extraction subgroups to allow for a specific analysis of extraction effects. Results Before treatment, the surgical group demonstrated, on average, a more severe skeletal discrepancy and increased dental compensations, compared with the orthodontically camouflaged group. After treatment, the mean SNA angle was greater, the ANB angle was more positive, the Wits appraisal was closer to ideal and the lower incisors were less retroclined in the surgery group. There was a small mean reduction in horizontal chin projection in the surgery group compared with a small increase in the camouflage group. The mentolabial fold and the lower lip curve were deeper, on average, and the lips less retrusive after surgery. There was a mean increase in upper incisor proclination during treatment in both the surgical and camouflage groups with a greater increase in the camouflage group. There was a significant reduction in upper incisor proclination and a subsequent greater increase in the ANB angle associated with upper premolar extractions in the surgical group compared with the non-extraction group. Lower premolar extractions in the camouflage group resulted only in a deeper mentolabial fold compared with those treated without lower extractions. Conclusions Class III patients selected for surgical treatment are likely to have more severe pretreatment dental and skeletal discrepancies than those selected for camouflage treatment. Surgical treatment is associated with significant decompensation of the lower incisors but, ultimately, not the upper incisors. Class III patients treated with either camouflage or surgery treatment are likely to finish with slightly proclined upper incisors. Generally, surgical treatment results in greater skeletal change, involving normalisation of the skeletal base relationship, a reduction in chin prominence, fuller lips, and a more favourable lip and chin contour.

A Novel Approach to Correction of Class II Malocclusion with Lower Premolar Extractions

A Novel Approach to Correction of Class II Malocclusion with Lower Premolar Extractions

Anesthetic Efficacy Assessment of Two Mental Nerve Block Techniques for Tooth Extraction

Background and aim: The mental-incisive nerve block can be used where lower premolars and anterior teeth require treatment. The aim of this study is to compare tow methods ofmental-incisive nerve block for extraction of the lower premolars and anterior teeth. Methods and materials: This randomized double blind split-mouth clinical trial study was performed on patients requiring extraction of lower premolars and anterior teeth bilaterally. Patients were divided into two groups (case and controls). On one side injection was administered distal to the second premolar while on the other side the injection was done between premolars. The teeth were matched in terms of clinical and radiographic features. Result: 40 patients (80 samples) with a mean age of 50.6 ± 12.7 were studied. According to the results, we had a 95% success rate with injection distal to the second premolar, but the success rate was 72.5% when the injection was done between premolars. Conclusion: The mental-incisive nerve block with injection done distal to the second premolar was more successful than between premolars.

Skeletal, dental and soft tissue changes in Class III patients treated with fixed appliances and lower premolar extractions

Abstract Background: Mild Class III malocclusions can be treated by upper incisor proclination and lower incisor retroclination following extraction of the lower first premolars. Aims: To compare the skeletal, dental and soft tissue changes in Class III patients treated with fixed appliances, Class III traction and lower first premolar extractions with the changes in a group of untreated Class III patients. Methods: The Treatment group consisted of 30 Class III patients (Mean age 13.69 ± 1.48 years) who were treated by upper and lower fixed appliances, Class III intermaxillary traction and lower first premolar extractions for 2.88 ± 1.12 years. The Control group consisted of 20 untreated Class III patients (Mean age 13.51 ± 0.95) matched for age and gender. The T1 to T2 changes in the treated and untreated groups were compared using a paired t-test while differences between the two groups were compared with an independent t-test. Results: During treatment, the upper incisors were proclined about 1 degree and the lower incisors were retroclined 8 degrees. Small, but statistically significant changes in SNB, Wits and the overlying soft tissues accompanied the changes in incisor inclination. At the end of treatment a positive overbite and overjet were achieved. The increase in lower facial height in the Treatment group was comparable with the change in the Control group. Conclusions: A range of mild to moderate Class III malocclusions can be treated by dentoalveolar compensation.

P.171 Orthodontic extraction: The riskless extraction of the impacted lower third molar close to the man

We aimed to find out whether extraction of lower premolars and subsequent closure of the space by a fixed appliance influenced the chances of mandibular third molars erupting.We compared angular and linear measurements of lower third molars on dental panoramic tomograms in 30 orthodontic patients with similar measurements from 30 patients with impacted third molars in intact arches.We found that the mesial angulation of lower third molars was reduced from 50° to 43 ° by orthodontic treatment (P< 0.001). Distance to the occlusal plane was reduced from 12 mm to 10 mm (P< 0.001). The space available increased from 4 mm to 11 mm (P< 0.001).We conclude that extraction of lower premolars and orthodontic treatment to achieve complete closure of the space allowed the positions of many impacted lower third molars to improve significantly.

Influence of orthodontic treatment on development of third molars

We aimed to find out whether extraction of lower premolars and subsequent closure of the space by a fixed appliance influenced the chances of mandibular third molars erupting.We compared angular and linear measurements of lower third molars on dental panoramic tomograms in 30 orthodontic patients with similar measurements from 30 patients with impacted third molars in intact arches.We found that the mesial angulation of lower third molars was reduced from 50° to 43 ° by orthodontic treatment (P< 0.001). Distance to the occlusal plane was reduced from 12mm to 10mm (P< 0.001). The space available increased from 4mm to 11mm (P< 0.001).We conclude that extraction of lower premolars and orthodontic treatment to achieve complete closure of the space allowed the positions of many impacted lower third molars to improve significantly.