Extraction Orthodontic Treatment Research Articles

Effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults: a retrospective cephalometric assessment.

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. 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). 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). 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.

Acceleration Techniques for Teeth Movements in Extractive Orthodontic Therapy

For a world that is constantly trying to speed up every procedure while obtaining the maximum result, traditional orthodontics have the biological limitation of using light and constant forces that allow tooth movement in a time frame that is only sometimes short. The treatment time could be lengthened if surgical procedures are programmed in the plan. Methods to accelerate tooth movement and reduce the duration of treatment while minimising complications are investigated and reported in the dental literature (e.g., low-level laser therapy, corticotomy, and micro-osteoperforations). This systematic review aims to analyse and summarise the strategies for quickening orthodontic movement during extraction orthodontic treatment, including any potential drawbacks or adverse consequences. The review will evaluate each approach’s effectiveness, safety, and evidence quality, compare their benefits and disadvantages, and analyse the implications for clinical practice and future research. Pubmed, Science Direct, Scopus, and Web of Science were searched using the keywords “acceleration” AND “dental movement” AND “orthodontic” between 1 April 2003 and 1 April 2023. After carefully scanning the study findings, forty-four publications were chosen for the systematic review. Most therapies discussed and provided in the literature seem promising and successful in enhancing orthodontic treatments. The success of operations like corticotomies, piezo-incisions, micro-osteoperforations, osteogenic distraction, low-level laser therapy, the administration of pharmacological treatments, and infiltrations with PRF and PRP were statistically significant and appear to be promising and effective in optimising orthodontic treatments. These strategies expedite treatment and enhance the patient experience, potentially broadening orthodontic appeal and minimising issues like cavities and enamel demineralisation. Further studies, with larger samples and standardised treatment protocols, are needed to investigate the efficacy of these tooth movement acceleration modalities.

Evaluation of pharyngeal airway space after orthodontic extraction treatment in class II malocclusion integrating with the subjective sleep quality assessment

Orthodontic treatment with premolar extractions is typically used to relieve dental crowding and retract anterior teeth for lip profile improvement. The aim of the study is to compare the changes in regional pharyngeal airway space (PAS) after orthodontic treatment with Class II malocclusion and to identify the correlations between questionnaire results and PAS dimensions after orthodontic treatment. In this retrospective cohort study, 79 consecutive patients were divided into normodivergent nonextraction, normodivergent extraction, and hyperdivergent extraction groups. Serial lateral cephalograms were used to evaluate the patients’ PASs and hyoid bone positions. The Pittsburgh Sleep Quality Index and STOP-Bang questionnaire were used for sleep quality evaluation and obstructive sleep apnea (OSA) risk assessment, respectively, after treatment. The greatest airway reduction was observed in hyperdivergent extraction group. However, the changes in PAS and hyoid positions did not differ significantly among three groups. According to questionnaire results, all three groups had high sleep quality and low risk of OSA, with no significant intergroup differences. Moreover, pretreatment-to-posttreatment changes in PAS were not correlated with sleep quality or risk of OSA. Orthodontic retraction with premolar extractions nither exhibit significant reduction in airway dimensions nor increase their risk of OSA.

Characteristic changes of the palatal rugae following orthodontic treatment

BackgroundBecause of the individuality of the palatal rugae, they are applicable for human identification purposes the same as the fingerprints. Therefore, it is important to assess the effect of different factors on rugae characteristics. We assessed the characteristic changes of the palatal rugae following extraction and expansion during orthodontic treatments. Before and after orthodontic treatment dental casts of 30 patients were scanned by 3Shape Trios 3D intraoral scanner, and superimposed in Geomagic X 2018 software. Displacement of 13 reference points was analyzed in three dimensions. The length of the palatal rugae was also measured. SPSS version 22.0 was applied for data analysis, using independent t test, sample t test, and chi-square test.ResultsThe alterations in the mean palatal rugae length were significant in the first right and third right ridges after extraction, and right and left second ridges after expansion treatment (P < 0.05). Changes in coordinates in the X, Y, and Z axes were significant at 8 points on the rugae after extraction, and 5 points after expansion treatment (P < 0.05). The changes in the sum of means of displacements were significant at all 13 points after extraction and expansion treatments (P < 0.05).ConclusionsThe palatal rugae do not remain stable during expansion and extraction orthodontic treatments. Some changes occurred in length, and the most medial and most lateral points on each ridge were displaced. The length of the incisive papilla did not change during treatment; thus, it can serve as a stable landmark. If we consider palatal rugae as an individual landmark, we can refer the patients after orthodontic treatment for scanning of their palatal rugae to document their post treatment pattern; but it should be noted that treatment relapse may change it again.

Effectiveness of micro-implant in vertical control during orthodontic extraction treatment in class II adults and adolescents after pubertal growth peak: a systematic review and meta-analysis.

To compare the effectiveness of micro-implant (MI) and conventional anchorage (CA) in vertical control during orthodontic extraction treatment of class II adults and adolescents after pubertal growth peak. Literature search was conducted through Cochrane Central Register of Controlled Trials (CENTRAL), PubMed, EMBASE, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang Database, VIP, China Biology Medicine (CBM), and other sources, from inception to December 2021. Randomized clinical trials (RCTs) and controlled clinical trials (CCTs) were included. Mean differences (MDs) with 95% confidence intervals (CIs) were conducted. A meta-analysis concerning change of mandibular plane, vertical change of upper and lower molar, change of occlusal plane, SNB, chin position, and profile was carried out. A total of 10,669 records were identified in the database search, and 19 studies (10 RCTs and 9 CCTs) were included in the final analysis. Compared with CA, MI significantly decreased mandibular plane angle and intruded upper molars. No significant difference was found in vertical change of lower molars, occlusal plane, SNB, chin position, and profile. MI seems to be more effective than CA in vertical control during orthodontic extraction treatment of class II adults and adolescents after pubertal growth peak. MI should be given priority when considering the vertical control of class II patients, which is beneficial to the counterclockwise rotation of mandible or at least prevention of deterioration of the profile.

Predictability of Proximal Enamel Thickness Assessment using Intraoral Periapical Radiographs: A Cross-sectional Study

Introduction: Measurements of tooth crown dimensions and enamel thickness are useful guides for interproximal stripping procedures aimed at creating space. In borderline non extraction orthodontic treatment cases, interproximal stripping is performed to gain space. Intraoral periapical radiographs and bitewing radiographs are commonly used to determine Proximal Enamel Thickness (PET). Aim: To determine the predictability of using IOPA-based PET measurements for assessing real/anatomic PET. Materials and Methods: This was a single-centre, crosssectional study conducted at Saveetha Dental College and Hospital, Chennai, Tamil Nadu, India, between March 2022 and April 2022. Digital Intraoral Periapical Radiographs (IOPAs) of 40 premolar teeth with intact crown structures were obtained using the paralleling technique. The PET of both the mesial and distal sides of the same teeth was measured using Carestream Imaging software. Subsequently, the extracted teeth were sectioned and examined under a Stereomicroscope (SM), and PET measurements of the mesial and distal surfaces were obtained along the heights of contour using ImageJ analysis software. Pearson’s correlation, along with linear and polynomial regression analyses, was performed using International Business Machines (IBM) Statistical Package for Social Sciences (SPSS) software. Results: A low but significant positive correlation between the PET of the sectioned teeth and the PET measured from IOPAs was observed (p=0.002, R=0.55). A significant difference in PET between the two methods for both sides was noted (p&lt;0.05). The mean distal enamel thickness was significantly greater than the mean mesial enamel thickness for both the IOPA and SM methods (p&lt;0.05). A polynomial regression equation, Y=2.084- 1.234X+0.318X3 , was established to predict PET of the sectioned teeth (Y) based on PET measured from IOPAs (X). Conclusion: The present study establishes a correlation between the true PET of teeth measured using cut-sections and PET measured from IOPAs, which are readily available in clinical practice. A correlation coefficient was determined, and PET can be predicted using IOPAs, although not with absolute accuracy. Distal PET was found to be higher than mesial PET, with no significant difference in enamel thickness between the two sides.

Mesial movement of maxillary first molars and vertical dimensional changes in orthodontic extraction treatment for patients with different facial morphology

Objectives: Primarily, to compare anchorage loss and changes in mandibular plane (MP) angle, overbite, and amount of horizontal, vertical, and angular movements of maxillary incisors in groups of hypodivergent, hyperdivergent, and normodivergent patients. Secondarily, to analyze the relationship between those factors. Methods: Pre- and post-treatment cephalograms of 89 patients treated with extraction of four bicuspids or two maxillary bicuspids were analyzed. The sample was divided into three groups based on their facial pattern measured by SN-MP angle (hypodivergent: &lt; 270, hyperdivergent: &gt;380, and normodivergent: 270-380). Linear and angular measurements included the distances of U1 tip and U6 mesial height of contour to Y-axis (i.e., line perpendicular to the X-axis, passing through Sella turcica), distance of U1 tip to Sella on X-axis, overbite, angulation of U1 to palatal plane, and SN-MP and ANB angles. Inferential statistics included one-way ANOVA, Chi-square test, independent t-test, and Pearson’s correlation coefficients. Results: Facial morphology did not primarily affect anchorage loss, because other factors such as crowding, severity of Class II molar relationship, and extraction modality played more impactful role (P&lt; 0.01). Change in mandibular plane angle was neither influenced by, nor correlated with, initial facial morphology or anchorage loss (P&gt; 0.05). Positive change in overbite was significantly correlated with facial pattern, incisor extrusion and retroclination (r= 0.30, 0.44, and -0.35, respectively, P&lt; 0.01). Conclusion: Anchorage loss in extraction orthodontic treatment is not influenced primarily by initial facial morphology. Anchorage loss is not significantly associated with MP angle reduction. Change in overbite can be achieved through incisor extrusion and retroclination.

A quantitative analysis of facial changes after orthodontic treatment with vertical control in patients with idiopathic condylar resorption.

This study aimed to investigate temporomandibular joint (TMJ) stability and three-dimensional (3D) facial changes in class II hyperdivergent patients with stable idiopathic condylar resorption (ICR) after orthodontic camouflage treatment with vertical control by using temporary anchorage devises (TADs). Nineteen skeletal class II hyperdivergent patients who were diagnosed with stable ICR underwent bicuspid extraction orthodontic treatment with vertical control via TADs were enrolled. TMJ was evaluated with the cone beam computerized tomography (CBCT) and clinical records before and after treatment. Changes in dental and skeletal parameters were evaluated with cephalometric and dental cast measurements. The 3D morphable model (3DMM) method was performed with the MeshMonk toolbox for the 3D facial analysis. After the reposition and landmark setting process, 3D facial heatmaps were used to illustrate facial changes, and the 3D deviations of landmarks were calculated. Both the imaging evaluation and clinical examination proved that TMJs remained stable after treatment. The retrusion of the upper and lower incisors reached 6.63 ± 0.79 mm and 3.78 ± 1.49 mm. The intrusion of the upper first molar reached 2.65 ± 0.75 mm, with a 2.27 ± 0.82° counterclockwise rotation of the mandibular plane. An upward shift of the soft tissue pogonion (2.34 ± 2.03 mm) and protrusion of Po-NB (0.82 ± 0.70 mm) was gained. Larger intrusion was found in the lower lip (3.29 ± 0.80 mm) than in the upper lip (2.20 ± 0.69 mm). Camouflage orthodontic treatment with TAD for vertical control is acceptable for skeletal class II hyperdivergent patients with ICR, which can improve the facial profile.

Study of pharyngeal airway morphology with CBCT: Benefits of four premolar extraction orthodontic treatments.

Four premolars extractions are routine procedures for correction of malocclusion, but will inevitably lead to a reduction of tongue space, whether this will weaken the pharyngeal airway remains a controversy. Cone-beam computed tomography (CBCT) radiographs of 80 patients who completed four premolar extraction orthodontic treatments were collected and divided into three anteroposterior skeletal groups according to the ANB (angle subspinale to nasion to supramentale) value. Linear, angular, cross-sectional area, and volumetric dimensions of the pharyngeal airway were measured using Dolphin Imaging 11.9 software. One-way analysis of variance and Pearson's correlation coefficient test were performed to assess the intergroup comparisons. Treatment changes were evaluated with two-sample t-tests. In intergroup comparisons, vertical linear and cross-sectional area differences were identified in S-Go/N-Me, VD1, VD1/N-Me, VD2/N-Me, AA, OAA and OMINI (p<0.05), while other measurements showed no significant differences. Angle2, the tilting degree of the pharyngeal airway, showed a positive correlation with ANB (p<0.05). As for the treatment changes, a significant increase was found in the pharyngeal airway in the Class I group (OUA p<0.05, VD1 p<0.001, VD2 p<0.05) and Class II group (VD1 p<0.001. VD2, p<0.05), and inversely, a significant decrease was found in the pharyngeal airway in the Class III group (OAA p<0.05, OMINI p<0.05, OUA p<0.05). No volumetric difference was identified. Interestingly, regarding the preoperative pharyngeal airway size, values trended to the mean value significantly. Four premolar extraction orthodontic treatments did not affect the pharyngeal airway volume except for the vertical liner and cross-sectional area dimensions. The trend of the gold standard suggested a positive influence of four premolar extraction orthodontic treatments.

Angular and positional changes of the maxillary third molars after orthodontic treatment with different premolar extraction patterns.

To evaluate the angular and positional changes of the maxillary second (M2) and third molars (M3) after orthodontic premolar extraction treatment according to patient skeletal classification and growth pattern. Panoramic radiographs of patients treated with extraction of the first or second premolars (n = 116) and patients treated without extraction (n = 92), taken before orthodontic treatment (T0) and after completion of multibracket appliance therapy (T1) were analyzed. Angle classification, growth pattern, crowding, and incisor inclination were recorded. The palatal (PP) and interorbital planes (IOP) were used as reference lines. Changes in the M3 angulation relative to PP and IOP (T0-T1) within the same group were evaluated with paired t-tests. One-way analysis of variance (ANOVA) and Kruskal-Wallis tests were used for comparisons between the groups. Accordingly, pairwise comparisons were performed with Mann-Whitney U-tests or independent t-tests (P < .05). The M3 angulation related to the PP and the IOP did not differ significantly between the extraction and nonextraction groups. The M2 angulation improved in the premolar extraction group between T0 and T1 (M2/PP, P < .001). According to Archer's classification, the change in the vertical position of M3 differed significantly between the extraction and nonextraction groups (P < .001). The angulation of M3 improved over time regardless of the extraction decision. The vertical eruption pattern of M3 was positively influenced only in the extraction group. M2 became significantly more upright in the orthodontic extraction treatment groups.

Palatal Anterior Teeth Retraction Assisted by Temporary Anchorage Devices - A Review

Successful orthodontic resolution of bimaxillary dentoalveolar protrusion depends on successful retraction of anterior dentition, which also involves acquiring proper buccolingual inclination and vertical position of anterior teeth. To fulfill these requirements, clinicians have devised numerous biomechanical and surgical orthodontic options. A palatal retractor for retraction of maxillary anterior dentition is the result of clinician’s long-time creative endeavors and an evolution of the biomechanical design. A palatal retractor splints the maxillary anterior dentition on the lingual side with bonded mesh plates connected by a supporting wire. Two long palatally extended arms are soldered to the supporting wire where adequate retraction force can be applied. Palatal retractors have several advantages over conventional bracket/wire systems. The two most prominent ones are biomechanical superiority and esthetic invisibility. As the palatal retractor is positioned on the lingual surface of the maxillary anterior dentition, it is not visible from the frontal view and since the anterior dentition retraction constitutes a significant portion of the total treatment time in extraction orthodontic treatment, it is a distinct esthetic advantage. Biomechanical disadvantage of the conventional bracket/wire system lies in its innate ineffectiveness of the torque and vertical control because of the long distance between the point of force application and the center of resistance of the anterior dentition. A combination of TADs and palatal retractors provides the possibility of maximizing control of both the torque and vertical position. This article aims to describe clinical considerations, applications, and results of palatal retractor use in clinical cases. Keywords: extraction treatment, anterior teeth retraction, palatal retractors, temporary anchorage devices.

Oropharynx and hyoid bone changes in female extraction patients with distinct sagittal and vertical skeletal patterns: a retrospective study

BackgroundPrevious studies have reported inconsistent effects of premolar extraction on the oropharynx and hyoid bones. Currently, no strong evidence is available regarding the effect of extraction on upper airway size. Hence, the aim of this study was to analyse the effects of first premolar extraction on the oropharynx and hyoid bone positions in female adult patients, and further explored differences in oropharynx and hyoid bone changes among skeletal patterns.MethodsThe study population included 40 female adult patients who did not undergo extraction and 120 female adult patients who underwent extraction of four premolars; the including patients had four distinct sagittal and vertical skeletal patterns. Cone-beam computed tomography was performed before (T0) and after (T1) orthodontic treatment. Eight oropharynx variables and five hyoid bone variables were measured using Dolphin 3D Imaging software. Paired and independent t-tests were used to analyse measurements between timepoints and groups, respectively.ResultsThe oropharynx volume increased significantly in the extraction group; changes did not differ significantly between extraction and non-extraction groups. Oropharynx variables did not differ significantly at T0 among the four skeletal pattern groups. After orthodontic extraction treatment, the oropharynx volume increased significantly in the class I-norm and class I-hyper subgroups, but not in the class II-norm and class II-hyper subgroups. Significant increases were observed in the oropharynx volume and most constricted axial area from T0 to T1 in the moderate retraction group, but not in the maximum retraction group. Extraction patients exhibited significant posterior movement of the hyoid, particularly among maximum retraction patients.ConclusionsIn female adult patients, first premolar extraction tends to increase the oropharynx size and cause posterior movement of the hyoid bone, particularly in skeletal class I patients. For skeletal class II and hyperdivergent patients with a narrow oropharynx, first premolar extraction does not negatively influence oropharynx size or hyoid bone position. The differences of oropharyngeal changes between moderate retraction patients and maximum retraction patients were not significant.

Buccal corridor changes in orthodontically treated extraction and non-extraction Class 1 patients

Patients seek orthodontic treatment mainly to improve their facial aesthetics and obtain an acceptable smile. It is purported that orthodontic extraction treatment may result in narrow buccal corridors which in turn may lead to unaesthetic smile. To determine if the dimensions of the buccal corridors are influenced by extraction or non-extraction treatment in Class 1 patients. Retrospective record-based study conducted between 2012 and 2017 at University of Pretoria Orthodontic department. Smile pictures of pre- and post-treatment Class 1 patients treated with or without premolar extractions were matched. Buccal corridors between the two groups were measured by measurement of visible maxillary dentition and oral aperture dimensions. Data analysis included frequencies and correlations using chi-square test, with a significance level set at p&lt;0.05. Seventy-one patient records met the selection criteria with the majority being females (70%). The age range was between 10 and 37 with a mean of 17.5 years. Thirty-five patients were treated with extractions and thirty-six patients with non-extraction treatment. There was a significant difference in the visible maxillary dentition pre and post treatment with extraction patients showing a 6 to 6 and non-extraction showing 5 to 5 dentition post treatment (p&lt;0.05). There were no differences in the ratios of the visible maxillary dentition and oral aperture in both groups pre and post treatment (p&gt; 0.05). Orthodontic treatment of Class 1 cases with premolar extraction did not lead to deleterious changes in the buccal corridors.

Extraction Orthodontic Treatment of Maxillary Central Incisors with External Root Resorption and Ankylosis due to Trauma

Extraction Orthodontic Treatment of Maxillary Central Incisors with External Root Resorption and Ankylosis due to Trauma

Evaluation of the stability of the palatal rugae using the three-dimensional superimposition technique following orthodontic treatment

ObjectivesTo determine the uniqueness and stability of the palatal rugae after orthodontic treatment. MethodsCast models of untreated subjects (n = 50) were obtained twice at intervals of 8–30 months. Cast models of patients who received non-extraction (n = 50) and extraction (n = 50) orthodontic treatment were obtained before and after treatment at intervals of 11–41 months and 14–49 months, respectively. All 300 cast models were scanned digitally. The palatal rugae were manually extracted and transformed into 3D point clouds using reverse engineering software. An iterative closest point (ICP) registration algorithm based on correntropy was applied, and the minimum point-to-point root mean square (RMS) distances were calculated to analyze the deviation of palatal rugae for scans of the same subject (intrasubject deviation [ISD]) and between different subjects (between-subject deviation [BSD]). Differences in ISD between each group and the deviation between ISD and BSD of all 150 subjects were evaluated. ResultsSignificant differences were found in the 150 ISD and 1225 BSD in each group, as well as the 150 ISD and 11,175 BSD across all groups. The mean values of ISD in untreated, non-extraction and extraction group were 0.178, 0.229 and 0.333 mm, respectively. When the first ruga was excluded in the extraction group, the mean ISD decreased to 0.241 mm, which was not significantly different from that in the non-extraction group (p = 0.314). ConclusionsOrthodontic treatment can influence the palatal rugae, especially in cases of extraction. Furthermore, variation mainly existed in the first ruga in cases of extraction. However, palatal rugae are still unique and may be used as a supplementary tool for individual identification. Clinical significanceThis study indicates that palatal rugae might be applied in the evaluation of orthodontic tooth movement and forensic individual identification. The registration algorithm based on correntropy provides a reliable, precise, and convenient method for palatal rugae superimposition.

Central incisor extraction orthodontic treatment of anterior tooth openbite: a case report

Central incisor extraction orthodontic treatment of anterior tooth openbite: a case report

Adaptive Changes in the Posterior Pharyngeal Wall Following Large Retraction of Incisors During Comprehensive Orthodontic Treatment.

To evaluate the effects of large retraction of incisors on the adaptive changes in the posterior pharyngeal wall and soft palate during comprehensive orthodontic treatment. Twenty-seven females with Class I mild crowding or spacing who required non-extraction treatment (group I) and 34 females with Class I bimaxillary dentoalveolar protrusion who required all first premolars extraction for the retraction of their incisors (group II) were included in the study. The effects of non-extraction and incisor retraction following all first premolars extraction orthodontic treatment on the sagittal dimensions of pharyngeal airway passage and posterior pharyngeal wall thickness were evaluated from pre- and post-treatment cephalograms. The dimensions of pharyngeal airway passage were comparable among the groups. The length of the soft palate increased (P < .01) and the thickness of the soft palate decreased (P < .01) following retraction of incisors, and the difference between the groups was significant (P < .05). The posterior pharyngeal wall thickness was reduced significantly at PPWT2 (P < .05), PPWT3 (P < .001), PPWT4 (P < .001), PPWT5 (P < .001), and PPWT6 (P < .01) regions following retraction of the incisors, and the difference between the groups was statistically highly significant. The large retraction of incisors during comprehensive orthodontic treatment in Class I bimaxillary dentoalveolar protrusion malocclusion subjects did not affect the sagittal dimensions of pharyngeal airway passage, but the thickness of the posterior pharyngeal wall reduced significantly as an adaptation to maintain the patency of the upper airway.

Extraction treatment on orthodontic patients with Stage Ⅳ/Grade C periodontitis: a preliminary study

Objective: To evaluate the effect of extraction treatment on orthodontic patients with Stage Ⅳ/Grade C periodontitis. Methods: Eight orthodontic patients with Stage Ⅳ/Grade C periodontitis (3 males, 5 females, 25~38 years old) who had finished extraction treatment during January 2003 and December 2013 were included in the study. The patients accepted periodontal treatment and extraction orthodontic treatment in the Department of Periodontology and Department of Orthodontics at Peking University School and Hospital of Stomatology. Clinical examination records and periapical films of 34 teeth adjacent to extraction sites (TAES) and 34 teeth non-adjacent to extraction sites (TNES) were evaluated and compared. Probing depth (PD) and relative bone height (RBH) before and after orthodontic treatment were also compared. Results: No significant difference was found between PD of TAES and that of TNES (P>0.05). After orthodontic treatment, RBH of TAES was increased by 8.19% (-3.36%,14.01%) (P<0.05). RBH of TAES far from extraction sites was elevated by 7.73% (-1.52%, 21.55%)(P<0.05). Tooth resorption rate of TAES was 13.1% (1.3%, 23.9%)and TNES was 4.3% (-8.19%, 12.5%) after orthodontic treatment, and the difference was statistically significant. Conclusions: Under proper combined periodontal and orthodontic treatment, stability of periodontal status in patients with Stage Ⅳ/Grade C periodontitis can be maintained. Relative bone height of extraction sites can be elevated after orthodontic treatment.

Cephalometric radiographic comparison of alveolar bone height changes between adolescent and adult patients treated with premolar extractions: A retrospective study

In orthodontic treatment, indication of dental extractions is very common and frequently used in adult patients. This situation is a recurrent concern among orthodontists, since age and extraction treatment are factors that may increase periodontal support loss. Therefore, this study aimed to evaluate adolescent and adult patients, orthodontically treated with maxillary premolar extractions, and compare both groups regarding the changes in alveolar bone height loss, retrospectively. Fifty-five patients were selected from the files of an Orthodontic Department and divided into 2 groups. The adolescent group comprised 30 patients with a mean age of 12.7 years (SD=1.4) and the adult group comprised 25 patients with a mean age of 25.0 years (SD=1.8). Periapical radiographs obtained at pre-treatment (T1) and posttreatment (T2) were evaluated. Wilcoxon tests were used to analyse intragroup treatment changes. Mann-Whitney tests were used to compare intergroup and inter-sex initial and final statuses and treatment changes. P<0.05 is considered to be statistically significant. Statistically significant increases in alveolar bone height loss of the maxillary central incisors were observed on the right and left sides of the adolescent (P=0.001 and P=0.002, respectively) and of the adult (P=0.001 and P<0.001, respectively) groups, during treatment. There were no significant differences in alveolar bone height between initial and final state, in treatment effects between adolescent and adult patients, in extraction patterns, and between males and females. Significant increase in alveolar bone height loss was found in both adult and adolescent patients orthodontically treated with maxillary premolar extractions. However, no significant differences were found regarding alveolar bone height changes after extraction orthodontic treatment between adolescent and adult patients.

Sınıf II Divizyon 1 Malokluzyonlu Hastada Headger İle Çekimsiz Ortodontik Tedavi Başarısının PAR İndeksi İle İncelenmesi

Bu çalışmanın amacı sınıf II Divizyon 1 malokluzyona sahip olan hastanın headgear ile tedavisinin sonuçlarının PAR (İyileştirme Değerlendirme Derecelendirme) indeksi ile incelenmesidir. PAR indeksi, tedavi öncesi ve sonrası alçı modeller kullanılarak tedavi sonucunu değerlendirmek hedefiyle oluşturulmuş bir indekstir. Çalışmamızda Sınıf II Divizyon 1 maloklüzyonu olan bir vakanın çekimsiz tedavisi Headgear ile yapıldı. Tedaviye bağlı olarak oklüzyonda meydana gelen değişiklikleri hesaplamak için (Ağırlıklı PAR puanı yüzdesindeki azalma- PAR %)'nın yöntemi kullanılmıştır. Ortodontik tedavi iyileşmesinin tespit edilmesinde PAR (%) yönteminin, tedavi öncesi PAR puanına göre değişikliği yansıttığı bilinmektedir. Olgumuzun PAR değerleri; PARbaşı 29, PARson 8'e düştü, PARfark 21 puanlık bir düşüş gösterdi ve PAR % = %72 hesaplandı ve bu durumda, PAR %, %70'ten daha büyük olduğu için "büyük ölçüde iyileştirmiş-çok başarılı" olarak kabul edildi.