Phase Of Orthodontic Treatment Research Articles

Reverse Engineering Orthognathic Surgery and Orthodontics in Individuals with Cleft Lip and/or Palate: A Case Report

This case report presents a virtual treatment simulation of the orthodontic treatment and surgery-first orthognathic surgery employed to treat a patient with a repaired unilateral cleft lip and alveolus with Class III malocclusion and lower third facial asymmetry. The patient exhibited a negative overjet of 9 mm, a missing lower right second premolar, and a 5 mm gap between the upper right central and lateral incisors with midline discrepancy. The three-dimensional virtual planning began with virtual pre-surgical orthodontics, followed by the positioning of the facial bones and teeth in their ideal aesthetic and functional positions. The sequence of steps needed to achieve this outcome was then reverse-engineered and recorded using multiplatform Nemostudio software (Nemotec, Madrid, Spain), which facilitated both surgical and orthodontic planning. The treatment included a two-piece segmental maxillary osteotomy for dental space closure, a LeFort I maxillary advancement, and a mandibular setback with bilateral sagittal split osteotomy to correct the skeletal underbite and asymmetry. A novel approach was employed by pre-treating the patient for orthognathic surgeries at age 11, seven years prior to the surgery. This early phase of orthodontic treatment aligned the patient’s teeth and established the dental arch form. The positions of the teeth were maintained with retainers, eliminating the need for pre-surgical orthodontics later. This early phase of treatment significantly reduced the treatment time. The use of software to predict all the necessary steps for surgery and post-surgical orthodontic tooth movements made this approach possible. Multi-step virtual planning can be a powerful tool for analyzing complex craniofacial problems that require multidisciplinary care, such as cleft lip and/or palate.

RANKL, OPG, and BALP Levels in Gingival Crevicular Fluids as a Biomarker on Alveolar Bone Remodeling in the Retention Phase of Orthodontic Treatment

Orthodontic treatment aims to correct malocclusion by applying orthodontic equipment that can transmit mechanical forces to the teeth, resulting in orthodontic tooth movement (OTM). The main problem in this treatment is the occurrence of relapse, so the post-treatment retention phase is critical to prevent relapse. Measuring potential biomarkers of alveolar bone remodeling is a proposed innovation in identifying alveolar bone deposition and resorption in the retention phase. This review highlights the role of essential biomarkers in alveolar bone formation, namely levels of bone alkaline phosphatase (BALP) and osteoprotegerin (OPG) and alveolar bone resorption, namely receptor activator of nuclear factor kappa-B ligand (RANKL) through gingival crevicular fluids. This level measurement is non-invasive and can predict the rate of alveolar bone remodeling to help determine the success of orthodontic treatment. Keywords: Alveolar bone remodeling, Biomarker, Orthodontic tooth movement, Retention phase

Influence of malocclusion on OHRQoL in adolescents in initial orthodontic treatment phase.

Besides correcting malocclusions, another main objective of orthodontic treatment is to improve patients' oral health-related quality of life (OHRQoL). This study aimed to assess changes in OHRQoL of children within the first six months of orthodontic therapy with fixed orthodontic appliances. 85 patients aged 11 to 14 years requiring fixed orthodontic appliance therapy were included. The children completed the German version of the Child Perceptions Questionnaire (CPQ-G-11-14) before (T0), 1 month (T1) and 6 months (T2) after the start of orthodontic treatment. The type of malocclusion was categorized according to the Index of Orthodontic Treatment Need (IOTN). The initial type of malocclusion affected the children's OHRQoL, whereas gender and age did not. The IOTN dental health component (DHC) had a significant impact on the CPQ score (median CPQ of 15.00 for the group DHC 4 vs. 22.50 for DHC 5, p = 0.032). The onset of orthodontic treatment initially affected the CPQ domains "Oral symptoms" and "Functional limitations, with a change versus baseline of 2.00 (p = 0.001), but improved again after 6 months. Regression analysis demonstrated that children with an IOTN DHC 5 malocclusion experienced a greater impact on their ORHQoL, as indicated by a CPQ score 7.35 points higher than that of children with an IOTN DHC 4 malocclusion (p = 0.015). At the beginning of orthodontic treatment, the OHRQoL slightly worsens, probably due to the discomfort and appearance of the appliances. However, 6 months after the start of orthodontic treatment, OHRQoL improved again in patients with severe malocclusion (IOTN 4 and 5), and approached baseline values. The results help the clinician to better understand specific aspects of oral health that may be affected by different malocclusions, thereby improving the child's satisfaction and overall quality of life.

The dewdrop retainrer clip – for easy placement of fixed lingual retainers

In Orthodontics, retention period is the most important phase of orthodontic treatment. Malocclusions requiring permanent retention for stability often need fixed lingual bonded retainers for holding the teeth in position. It has several advantages such not being visible and requires no patient cooperation during the retention phase. This article presents a simpler and innovative method of stabilizing the lingual retainer wire during bonding procedure by just holding it with prefabricated Dewdrop retainer holding clip.

Changes in the alveolar bone morphology among different patterns of incisor inclination during the alignment phase in orthodontic treatment without premolar extraction.

The present study investigated bone remodelling in the upper and lower incisor regions depending on the inclination pattern during the alignment phase of orthodontic treatment (OT). This prospective clinical study included 71 patients undergoing OT without premolar extraction. Cone beam computed tomography scans were taken before and after the alignment phase and the changes in the inclination, alveolar bone height (ABH) and bone thickness (BT) at levels 2, 3, 4, 6, 8 and 9 mm starting from the cementoenamel junction (CEJ) were determined. Teeth were divided into 'Retroinclination' (lingual crown inclination <0°), 'Proclination-low' (buccal crown inclination between 0° and 5°), or 'Proclination-high' (buccal crown inclination >5°). The alignment phase of OT resulted in ABH loss. The highest ABH loss in the maxilla was observed on the buccal side in the 'Proclination-high' and was 0.71 mm. ABH loss by 1.1 mm was observed in the mandible on the lingual side in the 'Retroinclination' group. The most significant changes in BT by up to 2 mm were observed at levels 6, 8 and 9 mm and these changes exhibited a moderate to strong correlation with the alterations in the inclination of individual incisors. At levels 2, 3 and 4 mm, the highest decrease in BT by up to 0.83 mm was observed on the palatal side of upper incisors in the 'Proclination-high' group. The direction and amount of tooth inclination partially determine changes in the bone parameters during the alignment phase.

Self-reported pain during different phases of orthodontic treatment with fixed appliance: A multi-centre randomized controlled trial in adolescents with crowding.

To compare self-reported pain levels across various treatment phases using passive self-ligating (Damon) and conventional (Victory) standardized fixed appliance systems. Adolescents (12-17 years old) with crowding and displaced teeth, planned for non-extraction treatment, were recruited from four orthodontic clinics. They were randomized into stratified blocks (1:1 ratio) using concealed allocation to receive Damon Q™ (34 boys, 28 girls) or Victory™ (39 boys, 31 girls). Pain and analgesic intake were assessed on seven different occasions with validated self-report questionnaires using a 10-grade scale. Of the 132 patients included, six were lost to follow up. Clinically relevant mean pain scores (≥4) were registered in both groups after bonding upper and lower arches and after insertion of 0.019 × 0.025 stainless steel archwire. The highest mean scores were reported on day two after bonding the upper arch (Damon 5.96, Victory 7.18, P = .011). In both groups, at least 40% reported taking analgesics during various treatment phases. The Damon group reported a lower intake of analgesics on days one and two (P = .042 and .037) after treatment initiation. In the entire sample, boys reported significantly higher mean pain scores than girls on the second and third days after bonding (P = .008 and .026, respectively). Lower pain levels were reported from the Damon group after bonding. In general, boys reported higher pain than girls did. Clinicians and adolescents need to be aware that clinically relevant pain levels can be expected not only after bonding but also in later phases.

Correlation of salivary cytokine IL-17A and 1,25 dihydroxycholecalciferol in patients undergoing orthodontic treatment.

The management of malocclusion has developed greatly in terms of treatment simulation and biomechanics, but treatment duration has been a great concern to the clinician as well as the patient. 1-25dihydroxycholecalciferol (biologically active form of Vitamin D) stimulates both osteoclasts and osteoblasts and was found to be the most significant in Orthodontic Tooth Movement acceleration. Inflammatory cytokines like IL-17A also play an important role in osteoclastogenesis and can enhance the rate of Orthodontic Tooth Movement.To perform a simultaneous evaluation of pro-inflammatory salivary cytokine IL-17A and salivary 1-25dihydroxycholecalciferol and to correlate their role on orthodontic tooth movement.A prospective cohort study was conducted among n = 97 patients. Saliva samples were collected from the patients at three phases of the orthodontic treatment, centrifuged and stored at 4℃ for evaluation of salivary 1-25dihydroxycholecalciferol levels and Pro-inflammatory cytokine IL-17A using ELISA.The mean salivary 1-25dihydoxycholecalciferol levels were 41.250ng/ml, 33.246ng/ml and 35.043ng/ml during the initial phase, lag phase and post lag phase of orthodontic treatment. The mean pro-inflammatory cytokine IL-17 A levels were 107.79pg/ml, 102.98pg/ml and 66.156pg/ml during the initial phase, lag phase and post lag phase of orthodontic treatment. There was a correlation between the salivary 1-25dihydroxycholecalciferol level and salivary cytokine IL-17A levels during the various phases of orthodontic treatment using Spearman's correlation rho test and linear regression analysis. There was no significant difference (p > 0.05) between 1-25dihydroxycholecalciferol levels and gender during the various phases (initial phase, lag phase and post lag phase) of Orthodontic treatment.There was a negative correlation between salivary 1-25dihydroxycholecalciferol level and salivary cytokine IL-17A levels during the various phases of orthodontic treatment. The level of 1-25dihydroxycholecalciferol and salivary cytokine IL-17A have been quantified during the various phases of Orthodontic treatment and this can be used clinically for the supplementation of Vitamin D in patients with low vitamin D levels and can enhance the treatment duration for the patient with less damaging effects to the surrounding tissues.

Comparison of the efficiency of initial dental alignment with Invisalign® aligners changed every 7 or 14 days in mature adults: Randomized clinical trial.

To compare the anterior crowding correction after sequential use of the first 5 aligners between two aligner exchange protocols (7 and 14 days) in mature adult patients. Thirty-six patients over 35 years who received orthodontic treatment with Invisalign® were randomly allocated to two different aligner replacement sequence protocols: Group 1: exchange every 7 days (n = 18); and Group 2: exchange every 14 days (n = 18). All patients were scanned with iTero Element 5D® (Align Technology) in two treatment times: at pre-treatment (T1) and after using the first five aligners (T2). Little's Irregularity Index (LII) and arch widths were evaluated with OrthoCAD software. Intra and intergroup comparisons were performed with the dependent and independent t-tests. The results were considered significant for P < .05. Thirty-five patients completed the study. Both groups' maxillary and mandibular Irregularity Indexesi were significantly lower at T2. There was no significant difference in inter-canine, inter-premolar, and intermolar distances.G2 (14 days) presented a greater decrease in mandibular irregularity than G1 (7 days). Both exchange protocols (7 and 14 days) effectively correct anterior crowding in the initial phase of orthodontic treatment with aligners in mature adult patients. However, the 14-day exchange protocol provided a greater correction in mandibular anterior crowding in the evaluated period than the 7-day exchange protocol.

BOLTON’S ANALYSIS OF FILIPINOS WITH DIFFERENT MALOCCLUSION GROUPS

Background: The orthodontic ‘‘finishing’’ phase is recognized for the multitude of details necessary to achieve an excellent result. In some cases, the finishing phase is very difficult, requiring the production of complicated biomechanical forces to reach a satisfactory orthodontic solution. A high percentage of these finishing-phase difficulties arise because of tooth size imbalances that could have been detected and considered during initial diagnosis and treatment planning. Many difficulties encountered during the finishing phase of orthodontic treatment arise due to lack of intermaxillary tooth-size matching. Bolton ratio is one of the most useful calculations for precise orthodontic diagnosis as it shows if there is a correct ratio between dental proportions.

Effectiveness of laser-engineered copper-nickel titanium versus superelastic nickel-titanium aligning archwires: A randomized clinical trial.

: To compare the effectiveness of laser-engineered copper-nickel titanium (SmartArch) and superelastic nickel-titanium (SENT) archwires in aligning teeth and inducing root resorption and pain experienced by patients. : Two-arm parallel groups with a 1:1 allocation ratio were used. The participants were patients aged 11.5 years and older with 5-9 mm of mandibular anterior crowding who were indicated for non-extraction treatment. The primary outcome was alignment effectiveness, assessed using Little's irregularity index (LII) over 16 weeks with a single wire (0.016-inch) in the SmartArch group and 2 wires (0.014- and 0.018-inch) in the SENT group (8 weeks each). Secondary outcomes included root resorption evaluated by pre- and post-intervention periapical radiographs and pain levels recorded by the participants during the first week. : A total of 40 participants were randomly allocated into 2 groups; 33 completed the study and were analyzed (16 in the SmartArch group and 17 in the SENT group, aged 16.97 ± 4.05 years). The total LII decrease for the SmartArch and SENT groups was 5.63 mm and 5.29 mm, respectively, which was neither statistically nor clinically significant. Root resorption was not significantly different between the groups. The difference in pain levels was not statistically significant for the first 5 days following wire placement; however, there was a significant difference favoring the SENT group in the final 2 days. : SmartArch and SENT archwires were similarly effective during the alignment phase of orthodontic treatment. Root resorption should be observed throughout the treatment with either wire. SmartArch wires demonstrated higher pain perception than SENT wires.

Orthodontic Relapse after Fixed or Removable Retention Devices: A Systematic Review

Retention constitutes a fundamental phase of orthodontic treatment, of which the patient must be made aware from the outset. Retention, which can be fixed or movable, has the task of maintaining over time and stabilising the results obtained during treatment. This study assessed the efficacy of using removable restraints versus fixed solutions for maintaining long-term outcomes. A comprehensive search across major databases—Pubmed, Web of Science, Scopus—used ‘relapse’ and ‘orthodontic’ as keywords to gather articles on relapse discussions. The primary focus was relapsed cases in post-fixed orthodontic therapy. Both fixed and removable retainer systems prove effective in preserving orthodontic achievements. While fixed devices require regular wire integrity checks, mobile devices require patient compliance, proper usage, and a recommended wear time. Studies indicate that fixed retainers are generally successful, with relapse rates varying based on the retainer type. Full-time use of removable devices surpasses night-only wear. Vacuum-formed and Hawley retainers offer similar effectiveness. Fixed retainers excel in long-term alignment stability, whereas removable ones have higher failure rates yet remain beneficial.

Smile Aesthetics Assessment in Patients Undergoing the Finishing Phase of Orthodontic Treatment: An Observational Cross-Sectional Study.

Objective To describe the smile characteristics of patients entering the finishing phase of orthodontic treatment. Methods This observational study involved a non-probabilistic sample of 48 patients. Clinical records served as the basis for determining the type of treatment (with or without extractions). Photographs were analyzed to obtain smile variables. Dental casts and panoramic radiographs were evaluated to ascertain the cast-radiograph evaluation (CRE) index. Univariate and bivariate analyses were conducted at a significance level of 0.05. Results The study evaluated 24 men and 24 women, with an average age of 20.10 ± 6.78 years. Fifty percent of the patients did not undergo extractions, and the average CRE index for the sample was 34.83 ± 9.01. Regarding the smile, a medium smile line was prevalent in 66.7% of cases, and a non-consonant smile arc was observed in 58.3%. Significant differences in the smile arc were found between patients with and without extractions (p=0.019). Right and left buccal corridors measured 2.52 mm ± 1.52 and 2.43 mm ± 1.37, respectively. The upper dental midline deviated by 0.80 ± 0.91 mm and had an angulation of 1.65 ± 2.05º. Both variables showed significant differences between Class I and Class II patients (p=0.020; p=0.027). Symmetrical smiles were also observed (1.05 ± 0.17). Conclusions Based on our findings, clinicians should focus on the smile arc in patients who have not undergone extractions and on the midline inclination in Class II patients. These appear to be the most common areas for improvement in patients who are in the finishing phase of treatment. Additionally, considerable variability exists in the smile characteristics of patients still undergoing orthodontic treatment, leaving room for further enhancement of results.

STUDY OF CYTOCOMPATIBILITY OF DIFFERENT SUPPLEMENTS IN GEL COMPOSITIONS USED FOR THE TREATMENT OF PERIODONTAL DISEASES IN ORTHODONTIC PATIENTS VIA EXPLORATION OF MECHANISMS OF THEIR CYTOPATHIC AND CYTOPROTECTIVE EFFECTS IN CULTURED HUMAN AND MOUSE CELLS

Introduction. A search continues for effective means which may reduce the overload of harmful factors, eliminate the inflammatory process, and reduce stress on the periodontal tissues during the active period of orthodontic treatment. We developed and patented the gel composition (GC) Benzidaflaziverdine prepared based on Proteflazid® (flavonoids) and benzydamine hydrochloride (BH) T-Sept® for the local treatment of the periodontal tissues in the form of a periodontal dressing in the orthodontic patients.&#x0D; The aim of this study was to evaluate the cytocompatibility of different combinations of components in gel composition based on flavonoid complex and benzydamine hydrochloride (Benzidaflaziverdine) used for the treatment of periodontal diseases in orthodontic patients. For this, mechanisms of their cytopathic and cytoprotective effects will be explored using cultured human and mouse cells.&#x0D; Methods. We studied the effect of different supplements used in GC Benzidaflaziverdine on the viability of pseudonormal human keratinocytes of the HaCaT line and mouse fibroblasts of the BALB-3T3 line, and mouse macrophages of the J774.2 line. Various methods of cell survival assessment were used: MTT-assay, staining of cells with fluorescent dyes Hoechst 33342 and Propidium iodide (PI), as well as a test for the genotoxic effects on cells (DNA comet assay). The antioxidant properties of the developed GC variants were evaluated using DPPH (1,1-diphenyl-2-picrylhydrazyl), Merck (Dam-stadt, Germany), and DCFDA-H2 (2’,7’-dichlorodihydrofluorescein diacetate).&#x0D; Results. We demonstrated that the Sample containing gel base and BH in the form of a solution (Tantum Verde®) possessed weak prooxidant properties. While the Sample contained gel base, powdered BH (T-Sept®) and Sample containing gel base and powdered BH (T-Sept® and Proteflazid®) possessed pronounced antioxidant properties.&#x0D; Conclusions. Tests with DPPH and DCFDA dyes were used to confirm the hypothesis regarding the cytoprotective effect of the patented gel composition Benzidaflaziverdine for local application in the form of a periodontal bandage due to the antioxidant activity of the flavonoid complex, which reaches the maximum level at the 2nd hour of exposure. This gel composition can be recommended for use in clinical periodontology for medical support of orthodontic patients before and during the active phase of orthodontic treatment.

The Orthodontics-Periodontics Challenges in Integrated Treatment: A Comprehensive Review.

Orthodontics and periodontics are intricately linked since adult orthodontics often implicate the periodontium. Periodontal intervention is needed throughout all phases of orthodontic treatment, from orthodontic diagnosis to mid-treatment periodontal assessment and postoperative evaluation. Invariably, periodontal health affects orthodontic success. Conversely, orthodontic tooth movements may serve as adjunctive therapy in patients with periodontal disease. This review aimed to provide a comprehensive understanding of the orthodontic-periodontic relationship for optimizingtherapeutic strategies and achieving the best treatment outcomes in patients.

Two-phase rehabilitation of patients with a forced position of the lower jaw: a clinical case

Relevance. Malocclusion correction in children very frequently requires several orthodontic appliances throughout the entire treatment period. The high prevalence of dental abnormalities in childhood determines the issue's relevance.Clinical cases' description. The article presents summaries from the records of the patients who presented for orthodontic care with malocclusion complicated by the forced position of the lower jaw. The authors implemented a two-phase orthodontic treatment protocol and achieved acceptable aesthetic and functional results.Conclusion. Laboratory-made plates with occlusal pads in the first phase of treatment of patients with mixed dentition contributes to the normalization of the lower jaw position and the alignment of the occlusal plane. In the second phase of orthodontic treatment, a standard silicone aligner allows for the improvement of dental arch relationship in the vertical, sagittal and transversal planes, normalization of dental arch form, and the correction of displaced teeth.

Efficiency of photobiomodulation on accelerating the tooth movement in the alignment phase of orthodontic treatment—A systematic review and meta-analysis

ObjectivesTo investigate the efficiency of photobiomodulation on accelerating the tooth movement in the alignment phase of orthodontic treatment. Materials and methodsThe data search was performed with PubMed, Embase, Scopus, and the Cochrane Library. Randomized clinical trials and controlled clinical trials evaluating the efficiency of photobiomodulation on accelerating tooth movement in the alignment phase were selected, and the characteristics of the included studies were collected in a customized data form. Data analysis was conducted by the random-effects model after risk of bias and certainty of evidence were assessed. ResultsFive randomized clinical trials and three controlled clinical trials were included in the final analysis. All included studies reported positive results except the study of Shehawy et al. The results of the analysis showed that photobiomodulation significantly increased the rate of tooth movement and reduced the treatment duration, compared with the control group. Although the heterogeneity was large among the included studies, it was improved after subgroup analysis. ConclusionsThis systematic review offered evidence that photobiomodulation can accelerate tooth movement in alignment procedures and reduce treatment time. Future studies are needed to find the best PBM protocol for orthodontic practice.

Pulp blood flow changes in maxillary and mandibular anterior teeth after orthodontic retraction: a prospective study

BackgroundPrevious studies of pulpal blood flow (PBF) changes in anterior teeth have been limited in the early phase of orthodontic treatment; less is known about the blood supply of anterior teeth in bimaxillary protrusion patients after orthodontic retraction.MethodsFifty bimaxillary protrusion patients (25 orthodontic patients ready for debonding and 25 non-orthodontic patients) were selected as study participants. The PBF of maxillary and mandibular anterior teeth were measured using laser Doppler flowmetry. For orthodontic patients, the PBF was measured at 1 day (T1), 1 month (T2), and 3 months (T3) after fixed appliance removal. Non-orthodontic patient PBF was measured as a control. Cone-beam computed tomography (CBCT) examinations before and after orthodontic treatment were performed for orthodontic patients to measure the root resorption. The anterior teeth in orthodontic group were further divided into subgroups according to root resorption and patient age.ResultsAt T1 and T3, PBF changes did not differ significantly between the orthodontic and non-orthodontic groups. Maxillary lateral incisor, maxillary central incisor, and mandibular lateral incisor PBFs at T2 were significantly higher in the orthodontic group (P = 0.048, P = 0.04, and P = 0.021). No significant difference in PBF was found between the root resorption and non-resorption subgroups at any time point. Adolescent patients showed a higher PBF in the maxillary lateral incisor at T2 (12.23 ± 3.48) relative to that at T1 (9.10 ± 3.76) and T3 (9.81 ± 2.80) with statistically significant difference (P = 0.020).ConclusionFor bimaxillary protrusion patients with four premolars extraction, PBF in the maxillary anterior teeth increased transiently after orthodontic appliance removal and then returned to non-orthodontic levels 3 months later. This effect was more pronounced in adolescents. The PBF of anterior teeth after orthodontic retraction may not be influenced by root resorption.

Laser Er:YAG-Assisted Debonding May Be a Viable Alternative to the Conventional Method for Monocrystalline Ceramic Brackets.

In orthodontic practice, due to the increased interest among patients in smile aesthetics, different types of brackets are now being used, with those most frequently applied being ones made of polycrystalline and monocrystalline ceramic. The aim of this study was to evaluate the laser Er:YAG-assisted debonding technique compared to conventional methods for removing monocrystalline ceramic brackets from human teeth. The study sample included 60 vital teeth (frontals of the upper jaw) from 10 patients who had monocrystalline ceramic brackets and were in the final phase of orthodontic treatment. The debonding procedure was carried out following a split-mouth study design, using either the conventional technique or laser Er:YAG 2940 nm radiation. For each tooth, three variables were evaluated: the patient's sujective tooth sensitivity associated with the debonding, the time required for debonding, and pulp blood flow microdynamics after the debonding. Three evaluation instruments were used to assess and quantify the treatment effects: (i) the Wong-Baker FACES Pain Rating Scale for pain assessment; (ii) a digital stopwatch/timer to measure the time required to remove the bracket; and (iii) laser Doppler flowmetry (LDF) for recording the pulp blood flow evolution. The statistical analysis of the recorded data showed a statistically significant difference between the two debonding methods regarding the tooth sensitivity during the debonding and the time required for the procedure. The subjective tooth sensitivity was reduced from a mean ± standard deviation of 3.07 ± 1.46 to 0.47 ± 0.86 on the Wong-Baker FACES scale (Wilcoxon signed rank, p &lt; 0.001). The necessary time for debonding was reduced by 0.697 ± 0.703 s per tooth (paired t-test, p &lt; 0.001). There was no difference in the blood microdynamics between the two debonding techniques. According to the results of this study, the laser Er:YAG-assisted debonding technique may be a viable alternative to the conventional method for monocrystalline ceramic brackets.

EARLY TREATMENT OF SKELETAL CLASS II BY FRÄNKEL FUNCTIONAL REGULATOR

In this case 7-year-old boy with severe distal bite caused by mandibular retrognathism was treated by Fränkel functional regulator type Ic. Aim: The aim of this paper was to show main skeletal and dental effects of Fränkel functional regulator type I in early treatment of skeletal distal bite. Appropriate timing for usage of functional appliance can successfully correct mandibular retrognathism and avoid later prolonged orthodontic treatment. Material and method: In this case boy in early mixed dentition with skeletal Class II was treated. Before treatment clinical examinations, study cast analysis, intraoral and extraoral photos, orthopantomogram and lateral cephalogram have been done. Active phase of treatment lasted 18 months. During this period patient wore an appliance continuously for 24 hours except during meals. An appliance was made on the basis of registered construction bite in position of posterior teeth in Class I. Patient activated screws in appliance once in 10 days. Lateral cephalogram, intraoral and extraoral photos have been done on the end of active phase of orthodontic treatment. Results and conclusion: Before treatment patient had severe Class II with deep bite and overjet of 11mm. Parameters on lateral cephalogram were: SNA 83°, SNB 77°, ANB 6°, Wits apprasial 9mm, SpP/MP 27°, FMA 21°, FMIA 59°, IMPA 100°, I/SpP 117°, Bjork 390°, Jarabak ratio 68%. After active phase of treatment patient had stable occlusion in Class I, reduced overbite and overjet of 3mm. At the end of the treatment measured parameters on the lateral cephalogram were: SNA 83°, SNB 79°, ANB 4°, Wits apprasial 0mm, SpP/MP 25°, FMA 20°, FMIA 59°, IMPA 101°, I/SpP 115°, Bjork 390°, Jarabak ratio 68%. Fränkel functional regulator is very successfull appliance for early treatment of skeletal distal bite, before pubertal growth spurt. This appliance causes skeletal and dentoalveolar changes and contributes to the correction of swallowing and speech.

Association of Craniofacial Patterns with the Curve of Spee and the Time Required for Orthodontic Levelling.

The curve of Spee (CoS) is an important parameter for an individualized treatment plan. The available information regarding a potential association of the depth of the curve of Spee with various skeletal craniofacial characteristics is conflicting and it is also unknown whether certain craniofacial parameters affect the duration of the levelling phase of orthodontic treatment. A prospective sample of 32 patients with mild to moderate crowding that underwent orthodontic treatment with full fixed appliances was used to study these topics. The craniofacial characteristics were captured on pre-treatment lateral cephalometric radiographs and measurements of the CoS were performed on the initial 3D digital dental models using the Viewbox 4 software. Non-parametric statistics and Spearman’s correlations were applied. Weak negative correlations were detected between the CoS depth and the SNA and SNB angles. There was no other association between the CoS and craniofacial parameters, including various anteroposterior measurements. Furthermore, there was no significant association of any craniofacial parameter with the duration of the levelling. Contrary to certain clinical beliefs, it can be argued that the craniofacial characteristics are not associated with the CoS and the time required for its levelling in subjects with moderate pre-treatment CoS depth.