Evaluation of condylar and mandibular movements on the upper airway during the use of mandibular advancement device for obstructive sleep apnea treatment.

OBJECTIVES: To evaluate the temporomandibular joint (TMJ), condylar and mandibular movements in obstructive sleep apnea (OSA) patients treated with mandibular advancement device (MAD) and to identify the influence of these anatomic factors on upper airway (UA) volume and polysomnographic outcomes after treatment. MATERIALS AND METHODS: Twenty OSA patients were prospectively treated with MAD. Clinical examinations, cone-beam computed tomography, and polysomnography were performed before MAD treatment and after achieving therapeutic protrusion. Polysomnographic variables and three-dimensional measurements of the TMJ, mandible, and upper airway were statistically analyzed. RESULTS: Condylar rotation, anterior translation, and anterior mandibular displacement were directly correlated with total UA volume, while vertical mandibular translation was inversely correlated with the volume of the inferior oropharynx. MAD treatment resulted in an increase in the volume and area of the superior oropharynx. There was no statistically significant correlation between condylar rotation and translation and polysomnographic variables. With MAD, there was a significant increase in vertical dimension, changes in condylar position (rotation and translation), and mandibular displacement. The central and medial lengths of the articular eminence were inversely correlated with condylar rotation and translation, respectively. The lateral length of the eminence was directly correlated with condylar translation, and the lateral height was directly correlated with condylar rotation and translation. CONCLUSION: Condylar and mandibular movements influenced UA volume. The articular eminence played a role in the amount of condylar rotation and translation. CLINICAL RELEVANCE: Individualized anatomical evaluation of the TMJ proves to be important in the therapy of OSA with MAD.

Genetic Polymorphisms of Estrogen Receptors α and ß are Associated with Craniofacial Measurements in Patients With Dentofacial Deformity.

Dentofacial deformities are characterized by abnormalities in craniofacial development that affects the individual's skeletal and occlusion, often causing functional and esthetic problems. In literature, there is an involvement of polymorphisms in estrogen receptor 1 (ESR1) and estrogen receptor 2 (ESR2) genes in craniofacial measurements. The aim of this study was to evaluate a possible association between polymorphisms in ESR1 (rs2234693 and rs9340799) and ESR2 (rs1256049 and rs4986938) genes with cephalometric measurements in individuals with dentofacial deformities. This cross-sectional study was performed with 158 individuals in the preoperative period of orthognathic surgery. The cephalometric measurements obtained through lateral cephalogram using Dolphin Imaging software. For genetic analysis, the DNA extracted from epithelial cells of the oral mucosa and were genotyped using the real-time polymerase chain reaction. The data found submitted to statistical analysis, through the Kolmogorov-Smirnov, Mann-Whitney, and Kruskal-Wallis tests, using the IBM SPSS software version 24.0. Considered a significance level of 0.05. We found association between polymorphisms and cephalometric measurements just in the female sex. The polymorphisms ESR1/rs9340799 ( P= 0.003), ESR1/rs2234693 ( P= 0.026), and ESR2/rs1256049 ( P= 0.046) were associated with the upper gonial angle (Ar-Go-N). The polymorphism ESR2/rs1256049 was also associated with the facial axis-rickets (NBa-PtGn) ( P= 0.004), anterior cranial base (SN) ( P= 0.036), and Y-axis (SGn-SN) ( P= 0.031).

Assessing the association between vitamin D receptor and dental age variability.

OBJECTIVES: To explore the association between genetic polymorphisms in vitamin D receptor (VDR), vitamin D serum levels, and variability in dental age. MATERIAL AND METHODS: This cross-sectional study was based on an oral examination, panoramic radiograph analysis, and genotype analysis from biological samples. Dental age was evaluated using two different methods: Demirjian et al. (Hum Biol 45:211-227, 1973) and Hofmann et al. (J Orofac Orthop.78:97-111, 2017). The genetic polymorphisms BglI (rs739837) and FokI (rs2228570) in VDR were genotyped through real-time PCR. The vitamin D level was also measured in the serum. Delta (dental age-chronological age) was compared among genotypes in VDR in the co-dominant model. Multiple linear regression analysis was also performed. An established alpha of 5% was used. RESULTS: Genotype distributions of BglI and FokI were not associated with dental maturity (p > 0.05). In the logistic regression analyses, genotypes in BglI and FokI and vitamin D levels were not associated with variability in dental age (p > 0.05). CONCLUSIONS: The genetic polymorphisms BglI and FokI in VDR and the vitamin D levels were not associated with variability in dental age. CLINICAL RELEVANCE: To unravel the factors involved in dental maturity can improve dental treatment planning in pediatric and orthodontic practice.

Treatment of Class II malocclusion with a customized lingual appliance combined with a Class II corrector.

Correcting a complete Class II malocclusion in an adult patient can be quite difficult. If the patient has a large skeletal discrepancy, orthognathic surgery is the treatment of choice. However, if the discrepancy is small or if the situation is borderline and the mandibular incisors are retroclined, Class II correctors can be used. This clinical report presents the orthodontic treatment of a 24-year-old woman with Class II malocclusion. Clinically, her maxilla was slightly protruded, and the mandible was well-positioned. She had uprighted maxillary and mandibular anterior teeth and a deepbite, and she opted for a more esthetically appealing orthodontic appliance. The treatment plan included leveling and alignment of the teeth in both arches, Class II correction, establishing Class I molar and canine relationships, correction of overbite and overjet, adjustment of midlines, and improvement of facial and dental esthetics. Orthodontic treatment consisted of customized lingual appliances combined with a Class II fixed corrector.

Three-dimensional skeletal and dentoalveolar sagittal and vertical changes associated with cantilever Herbst appliance in prepubertal patients with Class II malocclusion.

INTRODUCTION: This study aimed to assess sagittal and vertical skeletal and dentoalveolar changes through the use of 3-dimensional imaging in prepubertal Class II malocclusion patients treated with a cantilever Herbst appliance (HA). Condyle-glenoid fossa positional changes were also quantified. METHODS: This retrospective cohort study assessed 22 children (11.2 years ± 1.2) consecutively treated with a cantilever HA for 12 months and 11 untreated children (aged 9.3 ± 0.30 years) that served as controls. Cone-beam computed tomography was performed at baseline (T1) and at the end of the observation period (T2). Movements in the regions of interest were measured as linear displacements from cone-beam computed tomography images through algebraic calculations. A Student t test for independent samples was used for group equivalence testing at T1, and the treatment differences between T2 and T1 were evaluated by 2 analyses of covariance, one considering the expected growth unit as a covariate and the other with an annualized factor. RESULTS: The largest dental movement was a mesial movement of mandibular molars (3.70 mm), whereas the largest skeletal changes consisted of a larger relative length of the mandible (difference of 1.2 mm) in the HA group than in the control group. CONCLUSIONS: Within the study limitations (retrospective cohort, historical control group, and sample size), 3-dimensional imaging suggests that HA corrected Class II malocclusion in a predominantly prepubertal sample through more dental than skeletal changes. The changes were more significant in the sagittal than in the vertical direction. In addition, relative stability in the condyle-fossa relationship was noted.

Long-term stability of Class II malocclusion treatment with the cantilever bite jumper.

INTRODUCTION: This study aimed to assess the long-term stability of Class II malocclusion treatment with the Cantilever Bite Jumper (CBJ) after 13 years of follow-up. METHODS: The treatment group comprised 10 Class II Division 1 malocclusion patients treated with the CBJ, followed by fixed appliances, analyzed at 3 stages: pretreatment (aged 11.56-14.32 years), posttreatment (aged 16.34-19.58 years), and long-term posttreatment (aged 29.04-32.33 years). The control group included 15 subjects with normal occlusion. Intragroup treatment changes comparison was performed with repeated measures and analysis of variance followed by Tukey tests. Intergroup comparisons regarding the long-term posttreatment changes were performed with t tests. RESULTS: No statistically significant relapse was observed during the follow-up period. Morever, the treated group presented a significantly smaller increase in lower anterior facial height and greater retrusion of the lower lip than the control group in the posttreatment period. CONCLUSIONS: Treatment with the CBJ, followed by fixed appliances, is a stable alternative for Class II Division 1 malocclusion correction. The dentoskeletal and soft-tissue changes obtained during treatment remained stable in the long-term posttreatment follow-up.

Condyle-glenoid fossa relationship after Herbst appliance treatment during two stages of craniofacial skeletal maturation: A retrospective study.

OBJECTIVES: To perform a three-dimensional evaluation of the position of the condyles in patients treated with Herbst appliance (HA) in two stages of cervical vertebral maturation. SETTING AND SAMPLE POPULATION: Retrospective case-control study. Pubertal Herbst group (PHG; n = 24, mean age 14.5 years, CS 3 and CS 4) and pre-pubertal Herbst group (PPHG; n = 17, mean age 9.9 years, CS 1 and CS 2) were contrasted with comparison groups of non-orthopaedically treated Class II patients in pubertal (PCG; n = 17, mean age 13.9 years) and pre-pubertal maturational stages (PPCG; n = 18, mean age 10.6 years). MATERIALS AND METHODS: Cone-beam computer tomography scans were taken before treatment (T0) and at T1 after 8 to 12 months. Point-to-point measurements of the displacement of the condyles between T0 and T1, relative to the glenoid fossae, were performed in the X, Y, Z and 3D perspectives. Qualitative assessments using semi-transparent overlays and colour mapping also were produced. RESULTS: The displacement of the condyles within the glenoid fossae in the treated groups was small (<0.75 mm; P > .05). Relative to the glenoid fossa, condylar position at T1 was similar to T0 in pre-pubertal and pubertal groups (P > .05). Similar condylar rotations from T0 to T1 were observed in Herbst and comparison groups, and no significant difference was found between pre-pubertal and pubertal patients. CONCLUSIONS: Regardless the stage of skeletal maturation, HA treatment did not change the condyle-glenoid fossa relationship.

Three-dimensional airway changes after adenotonsillectomy in children with obstructive apnea: Do expectations meet reality?

INTRODUCTION: The assessment of the volumetric changes of the airways after adenotonsillectomy has gained popularity among orthodontists, but the validity of such evaluation is not clear. METHODS: Thirty patients with obstructive sleep apnea diagnosed with the use of polysomnography (PSG) were evaluated according to the Apnea and Hypopnea Index (AHI), the obstructive apnea index (OAI), the oxygen desaturation index (ODI), the lowest oxygen saturation (LSpO2), and the average oxygen saturation (ASpO2). The volume and the minimal cross-section of lower (oropharynx and velopharynx) and upper (nasopharynx) spaces of the airways were calculated. Patients were adenotonsillectomized; posttreatment data were collected after 12 months. Thirty comparison patients also had the volume of airways evaluated. RESULTS: A statistically significant improvement (P < 0.05) of most PSG parameters was observed after adenotonsillectomy: AHI from 14.5 to 5.2, OAI from 9.4 to 5.5, ODI from 14.6 to 6.5, and LSpO2 from 77% to 94%). A significant increase in airway volume of the lower space (from 2571.5 mm3 to 5276.3 mm3) and the upper space (from 726 mm3 to 1056.9 mm3), as well as in the minimal cross-section of the airways (from 98.5 mm2 to 335.8 mm2) was found in adenotonsillectomy patients. No significant volumetric changes of the airways were observed in the comparison patients. No significant correlation was found between PSG parameters and the dimensions of the airways before adenotonsillectomy. No significant correlation was found between changes of the PSG parameters and changes of the dimensions of the airways 12 months after the adenotonsillectomy. CONCLUSIONS: Adenotonsillectomy contributed to the increase of the airway volume and minimal cross-section, and to the improvement of the PSG parameters, but there was no correlation between the magnitude of the anatomic changes and the improvement of the breathing mode.

Sclerotherapy and cryotherapy in the management of oral vascular lesions: a series of 10 cases.

Vascular anomalies such as hemangiomas or vascular malformations can produce negative esthetic effects in the maxillofacial region. These negative effects are the main complaints of patients. The clinical therapeutic efficacy of cryotherapy and sclerotherapy in the treatment of these lesions was evaluated in 10 patients who were clinically diagnosed with vascular lesions. Lesions were submitted to either cryotherapy or sclerotherapy, and follow-up showed that cryotherapy and sclerotherapy both were clinically effective in treating oral vascular lesions. Cryotherapy is an easy to perform method that requires only 1 session, but the high cost of the equipment is a limiting factor. Sclerotherapy is a noninvasive treatment widely accepted by patients, but more than 1 session is required.

Demirjian's and Cameriere's Methods for the Assessment of Dental Age Estimation in Children from a Southern Brazilian City.

The chronological age estimation of living individuals is a crucial part of forensic practice and clinical practice, such as in orthodontic treatment. It is well-known that methods for age estimation in living children should be tested on different populations. Ethnic affiliations in Brazil are divided into several major groups depending on the region, with the south of Brazil being known for its German immigration. (1) Background: This study aimed to evaluate the correlation between chronological age and dental age using Demirjian's method and Cameriere's method in a group of children from Joinville, South Brazil to investigate if both methods can be used to estimate dental age in this population. (2) Methods: The sample consisted of 229 panoramic radiographs (119 were males and were 110 females) from Brazilian children (ages ranging from 6 to 12 years). The chronological age at the time of the panoramic radiographic exam was calculated for each child. The dental age was estimated according to Demirjian's method and Cameriere's method. All continuous data were tested for normality by using the Shapiro-Wilk test. The Pearson correlation coefficient test was applied. An alpha of 5% (p < 0.05) was used for all analyses. (3) Results: The mean chronological age was 8.75 years. According to Demirjian's method, the mean dental age was 9.3 years, while according to Cameriere's method, the mean dental age was 8.66 years. A strong correlation between chronological age and dental age according to Demirjian (r = 0.776 and p < 0.0001) and Cameriere (r = 0.735 and p < 0.0001) was observed for both genders. (4) Conclusions: Both methods presented a good correlation with chronological age in the studied population and could be used to assess dental age in this population.

Stability of fiducial cephalometric landmarks of growing Class II malocclusion patients: a three-dimensional retrospective study.

OBJECTIVES: To evaluate three-dimensionally (3D) the stability of Nasion (Na), Sella (S), Basion (Ba), Porion (Po), and Orbitale (Or) in different age groups of growing Class II malocclusion patients and, additionally, to assess rotational changes of the S-Na and Ba-Na lines and the Frankfurt Horizontal Plane (FHP). MATERIALS AND METHODS: Cone-beam computed tomography studies of 67 Class II division 1 malocclusion patients, acquired at baseline (T0) and 1 year later (T1), were retrospectively assessed. Anterior cranial fossa was used for volumetric superimposition. Subjects were grouped according to their age at T0: group 1 (G1) (8-10 years), G2 (11-13 years), and G3 (14-17 years). Quantitative assessments of the 3D linear displacements (Euclidean distance) in the position of Na, S, Ba, Po, and Or were performed. Displacement in the X, Y, and Z projections and the rotation of S-Na, Na-Ba, and FHP were also quantified. RESULTS: All cephalometric landmarks showed 3D displacement (P = .001) in the three age groups. Orbitale remained stable in the vertical and sagittal dimension from 8 to 17 years (P > .05). S-Na, Na-Ba, and the FHP showed statistically significant angular rotation (P < .05) in younger patients (G1), while in older individuals (G2 and G3) they were stable (P > .05). CONCLUSIONS: Na, S, Ba, and Po showed vertical and sagittal positional changes relative to the anterior cranial fossa during the growth of Class II individuals. After age 11, S-Na, Na-Ba, and FHP did not show rotation and, thus, are valid parameters for angular cephalometric analysis in Class II growing patients.

Correlation between Insulin-Like Growth Factor I and Skeletal Maturity Indicators.

Objective: The purpose of this study was to evaluate the correlation between the growth maturity indicators in orthodontic patients. Design: This cross-sectional study was performed on 37 orthodontic patients (17 males and 20 females). An anamnesis, clinical and image examination, and blood sample collection were performed. The inclusion criteria were non-syndromic Class II patients of both gender, age ranging between 10 to 16 years. The lateral cephalometric radiographs were evaluated using 6-stage cervical vertebrae maturation (CVM) technique. The hand-wrist radiographs were staged using the 11-stage skeletal maturation indicator (SMI) technique. Blood was collected in the same week of the images to quantify IGF-1 levels in serum. Data were tested for normality by Shapiro-Wilk test. The Pearson test was used to determine the correlation strength between the variables (alpha of 5%). Results: A strong correlation was observed only between SMI stages and CVM stages in the total sample (r=0.864; p<0.0001) and according to the gender (r=0.793; p<0.0001 for females; and r=0.753; p<0.0001 for males). IGF-1 was only moderately correlated with SMI stages and CVM stages. Conclusion: Hand-wrist and cervical vertebral stages were strongly correlated among them, however, IGF-1 was only moderately correlated with both skeletal maturity indicators.

A retrospective study of the influence of obesity on polysomnography and cephalometric parameters in males with obstructive sleep apnea.

OBJECTIVE: Evaluate the influence of obesity on the polysomnographic and cephalometric parameters in obstructive sleep apnea (OSA). METHODS: Fifty records of male patients with OSA, containing information on dental, medical, polysomnographic, and cephalometric exams were selected. The degree of obesity was based on Body Mass Index (BMI). Group I comprised normal or overweight individuals (BMI ≤ 29.9 kg/m2), whereas Group II consisted of obese individuals (BMI ≥ 29.9 kg/m2). RESULTS: BMI significantly correlated with apnea and hypopnea index (p < 0.0005), minimal oxyhemoglobin saturation (p < 0.0005), and two cephalometric variables (soft palate length, p = 0.01 and width, p = 0.01). Group II showed a significant correlation with the position of the hyoid bone (p = 0.02). Soft palate length and width significantly differed between groups (p = 0.014; 0.016). CONCLUSION: Obese males present wider and longer soft palate dimensions, and patients with a greater BMI present a more inferiorly positioned hyoid bone.

Stability of Class II corrections with removable and fixed functional appliances: A literature review.

BACKGROUND: Class II functional appliances have been used in orthodontics for over 100 years. Although the stability of corrections is one of the main goals of orthodontic treatment, there is a paucity of longitudinal studies on the long-term stability of treatment of Class II malocclusion based on functional appliances. METHODS: This narrative review attempts to summarize the limited related evidence available and discusses the clinical implications of important aspects related to occlusal and skeletal changes that arise after Class II malocclusion treatment with functional appliances. RESULTS: The occlusal changes obtained through Class II functional treatment do mostly exhibit long-term stability. While mild posttreatment changes occurred, they were most likely due to physiologic aging processes and not likely associated with actual treatment relapse. Long-term retention in the lower jaw would be particularly beneficial. A stable occlusion with good intercuspation in the posterior arches seems more likely to preserve a Class I occlusion after treatment through dentoalveolar compensatory mechanisms. After treatment, the maxilla and the mandible do grow anteriorly, with the mandible growing more than the maxilla. Patients treated with functional appliances are not likely to develop TMJ disorders over the long term. CONCLUSIONS: Long term skeletal corrections achieved with functional appliances seem to be overall stable. Class II molar and overjet relapses can be likely explained by a combination of tooth movement and an unfavorable posttreatment maxillomandibular growth pattern, especially when combined with unstable interdigitation of the posterior teeth. No specific intermaxillary retention approach has been assessed yet.

Esthetic perception of facial profile changes in Class II patients treated with Herbst or Forsus appliances.

OBJECTIVE: To evaluate the esthetic perceptions of orthodontists and laypersons for facial profile changes after orthodontic treatment using Herbst or Forsus appliances. MATERIALS AND METHODS: Pre- and posttreatment facial profile contour images of 20 Class II patients treated with Herbst (group H; n = 10) and Forsus (group F; n = 10) appliances were analyzed by 30 orthodontists and 30 laypersons, who graded them from 1 (unattractive) to 10 (very attractive) using a visual analog scale. Two assessments were carried out with a 15 day-interval. In the first evaluation, 40 images were presented in a random sequence. In the second evaluation, initial and final facial profile images of each patient were randomly presented side by side. To compare groups in relation to treatment method, Mann-Whitney tests were used. To evaluate differences between time points, Wilcoxon tests were used. RESULTS: In the first evaluation, there was a significant difference between initial and final images only for group H, for both laypersons (P = .017) and orthodontists (P = .037). There was also a significant difference between laypersons and orthodontists in their ratings of posttreatment Herbst appliance profiles (P = .028). There was no significant difference between initial and final facial profile images for group F and no significant differences between or within evaluator groups in their ratings of initial or final Forsus appliance profiles. In the second evaluation, there was a significant difference between appliance groups only for laypersons, who considered cases treated with the Herbst appliance more attractive than those treated with the Forsus (P = .031). Laypersons also considered Herbst profiles more attractive than did orthodontists (P = .047). CONCLUSIONS: Class II malocclusion treatment using the Herbst appliance may produce a more esthetically improved facial profile silhouette compared with Forsus appliances. The magnitude of perceived changes may not be considered clinically relevant.

Class II correction with the Cantilever Bite Jumper.

OBJECTIVE: To identify the skeletal, dentoalveolar, and soft tissue changes that occur during Class II correction with the Cantilever Bite Jumper (CBJ). MATERIALS AND METHODS: This prospective cephalometric study was conducted on 26 subjects with Class II division 1 malocclusion treated with the CBJ appliance. A comparison was made with 26 untreated subjects with Class II malocclusion. Lateral head films from before and after CBJ therapy were analyzed through conventional cephalometric and Johnston analyses. RESULTS: Class II correction was accomplished by means of 2.9 mm apical base change, 1.5 mm distal movement of the maxillary molars, and 1.1 mm mesial movement of the mandibular molars. The CBJ exhibited good control of the vertical dimension. The main side effect of the CBJ is that the vertical force vectors of the telescope act as lever arms and can produce mesial tipping of the mandibular molars. CONCLUSIONS: The Cantilever Bite Jumper corrects Class II malocclusions with similar percentages of skeletal and dentoalveolar effects.

Correlation between pain and hyalinization during tooth movement induced by different types of force.

OBJECTIVES: To evaluate the correlation between pain and tissue reactions during induced tooth movement (ITM). MATERIALS AND METHODS: Forty-two male Wistar rats (Rattus norvegicus; ∼90 days of age, 300 g) were used. The animals were divided into seven groups of six rats each: one control group and six experimental groups subjected to ITM by continuous force (CF) or interrupted continuous force (ICF) for 1, 3, and 5 days. Hyalinization of the periodontal ligament (PL) and occurrence of pain were observed. Animal behavior (walking, climbing, immobile posture, resting/sleeping, and directed face grooming) and the presence of chemical mediators associated with nociception, cyclooxygenase-2 (COX-2), and interleukin-1 beta (IL-1ß) in the PL were analyzed. RESULTS: There was a moderate positive correlation between hyalinization and the presence of COX-2 (rs = 0.404; P < .05) and IL-1ß (rs = 0.429; P < .05). There was a moderate negative correlation between hyalinization and exploratory behaviors (walking, r = -0.586, P < .01; climbing, r = -0.573, P < .01), and a moderate positive correlation between hyalinization and resting/sleeping (r = 0.467; P < .01). CONCLUSIONS: The results suggest a correlation between pain and undesirable tissue reactions in ITM.

Clinical Steps for Restoration of Fractured Anterior Teeth: Color Protocol with Non-VITA Scale.

Direct composite resin restorations are commonly provided because of their satisfactory esthetics and minimal wear of opposing tooth structure. Recent restorative systems may not follow the nomenclature of the classical VITA shade guide, using instead a simplified resin color system. A better understanding of these systems and their behavior regarding the incidence of light is an excellent approach to anterior restorations, especially for fractured anterior teeth. This paper demonstrates the color selection and clinical sequence for the natural reproduction of tooth structure using a resin system that does not follow the VITA classical scale.

Orthodontic Treatment of Ankylosed Maxillary Incisor through Osteogenic Distraction and Simplified Biomechanics.

Ankylosed teeth may have a significant esthetic and functional impact especially at the anterior segment of the upper arch. Treatment of ankylosed teeth is challenging. The objective of this case report is to describe a clinical case in which an ankylosed tooth was treated with the use of osteogenic distraction associated with simplified orthodontic biomechanics. A 17-year-old female Caucasian patient presented with a Class II malocclusion, severe maxillary dental crowding, moderate mandibular dental crowding, anterior open bite, upper midline deviation to the right, and upper right central incisor in infraocclusion due to ankylosis. Treatment involved the use of the ankylosed tooth as anchorage for the distalization of the right upper segment to correct the Class II malocclusion and to create space prior to surgery. After one week of surgical osteotomy, traction of the tooth and bone segment was initiated with the use of intermaxillary elastics. The ankylosed tooth was moved to the desired position. Bone formation and mucogingival tissue adaptation were observed. Thus, esthetic and functional improvement was achieved. Osteogenic distraction associated with simplified orthodontic biomechanics is an alternative to the treatment of ankylosed teeth which can replace the use of distractor screws, making treatment simpler and more accessible.