Microsoft Word Tom tat LA (Eng) 12 10 docx MINISTRY OF EDUCATION AND TRAINING MINISTRY OF DEFENCE 108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES NGUYEN THI MY HANH RESEARCH OF TREATMENT[.]
MINISTRY OF EDUCATION AND TRAINING THE THESIS WAS DONE IN: 108 INSTITUTE OF CLINICAL MINISTRY OF DEFENCE MEDICAL AND PHARMACEUTICAL SCIENCES 108 INSTITUTE OF CLINICAL MEDICAL AND PHARMACEUTICAL SCIENCES - Supervisor: Prof Dr Trinh Dinh Hai Assoc.Prof.Dr Le Thi Thu Ha NGUYEN THI MY HANH Reviewer: RESEARCH OF TREATMENT IN PATIENT WITH ANGLE CLASS I MALOCCLUSION, NONEXTRACTION USING SELF- LIGATING BRACKETS AND BROADER ARCHWIRES This thesis will be presented at Institute Council at: 108 Speciality: Odonto- Stomatology Institute of Clinical Medical and Pharmaceutical Sciences Code: 9720501 Day ABSTRACT OF MEDICAL PHD THESIS Month Year The thesis can be found at: National Library of Vietnam Library of 108 Institute of Clinical Medical and Pharmaceutical Sciences Central Institute for Medical Science Infomation and Hanoi – 2023 Tecnology INTRODUCTION patient's wish but also the first priority for the orthodontist In recent years, orthodontic treatment with fixed appliances has developed rapidly Many types of fixed orthodontic appliances have been invented, giving doctors and patients more and more treatment options The use of the self-ligating bracket system and broader archwire helps to reduce tooth crowding in cases where no extraction is possible In Vietnam, this technique has been applied but no research has been published, so the topic is urgent, topical and has scientific significance PRACTICAL MEANS AND NEW CONTRIBUTIONS The study presents some clinical and radiographic characteristics of patients with class I Angle malocclusion, crowded teeth Efficacy of self-ligating bracket system and broader archwires in treatment STRUCTURE OF THE THESIS In addition to the introduction, the thesis has chapters: Chapter I – Research overview – 37 pages, Chapter II – Research objects and methods – 23 pages, Chapter III – Results – 30 pages, Chapter IV – Discussion – 37 pages The thesis has 25 tables, 09 charts, 33 pictures, 127 references (98 English, 29 Vietnamese) Malocclusion is the deviation of the relationship between the teeth on one jaw and/or between two jaws that affects health and is often combined with other facial aberrations Class I malocclusion is the most common deviation Salim's study in 2021 showed that the rate of class I malocclusion was 52.6%, in which the rate of crowded teeth accounted for 71.1% Crowded teeth are one of the main reasons that patients come for examination and treatment Non-extraction treatment is not only the desire of the patient but also the top priority for the orthodontist Using self-ligating brackets and broader wires to widen the arch to the sides or widen the arch anteriorly That helps reduce crowding in cases where teeth are not extracted The study of Maltagliati LA and Jiang RP et al (2008) using the Damon self-ligating bracket system and Damon's extension archwire resulted in an increase in width in the molar area after treatment In our country, the technique of orthodontic treatment with self-ligating brackets has been applied for recent years However, no studies have been published on this issue Therefore, we carried out the project "Research study of treatment in patient with class I malocclusion, nonextraction using self- ligating brackets and broader archwires" with objectives: Describe some clinical and radiographic characteristics of the group of patients with class I Angle malocclusion who are indicated for non-extraction treatment Evaluation of the treatment results of these patients with self-ligating bracket system and broader archwire THE URGENCY OF THE THESIS Malocclusion not only causes discord in the relationship of the mouth and face, affecting aesthetics, but also creates favorable conditions for many other diseases to develop such as periodontal disease, tooth decay, and gum disease eat … Non-extraction treatment is not only the CHAPTER I RESEARCH OVERVIEW 1.1 Class I malocclusion Class I malocclusion: the mesial lateral cusps of the maxillary first permanent molars align with the mesial lateral sulcus of the mandibular first permanent molars, but the occlusal line is not due to anterior teeth growing out of place, rotating teeth , or other causes 1.2 Epidemiology In Vietnam: a study by Vuong Ngoc Thin et al in 2018 showed that class I malocclusion accounted for the highest rate with 41.7%; Nguyen Trong Hoa's study on a group of students in South Korea showed that the normal occlusion rate accounted for 6.7%; Class I malocclusion accounted for 22.4%; Nguyen V A study on the occlusal status of 12-yearold children showed that the rate of class I occlusion was 62.2% In the world: Research by Lin et al published in 2018 showed that the rate of class I malocclusion was 30.07%; crowded teeth accounted for 49.2%; Xu et al.'s study published in 2019 showed that class I Angle malocclusion has a rate of 30.96%; In 2019, Sundareswaran announced research results on the rate of class I malocclusion is 89.9%; Salim's study published in 2021 showed that the rate of class I Angle malocclusion was 52.6% 1.3 Clinical and radiographic characteristics of Class I Angle malocclusion, crowded teeth, no extraction 1.3.1 Clinical characteristics * Frontal views: usually has a medium or short face shape, the facial layers are symmetrical or slightly different, normally at rest, the lips are slightly touching, the muscles around the mouth are completely relaxed, the upper front teeth are exposed about -5mm * Profile: usually straight or convex Angle of nose and lips: created by two lines passing through the point of the base of the nose wing, tangent to the curve connecting the tip of the nose to the base of the nose and the line tangent to the upper lip The mean value of this angle is 100 ± 10, the nasolabial angle is one of the criteria to consider, evaluate and make the decision to extract teeth or not to extract teeth in orthodontic treatment * Occlusal characteristics: - Malocclusion in the anteroposterior direction: The mesial lateral cusps of the maxillary first permanent molars match the mesial lateral grooves of the mandibular first permanent molars, but the occlusion line is not correct due to the eruption of the anterior teeth, misplaced rotated teeth, or other causes - Sagittal: Class I malocclusion is often accompanied by malocclusion such as deep bite, open bite or midline deviation - Horizontal: The patient may have a normal posterior occlusal relationship or a narrow jaw leading to a posterior crossbite - In each arch: Crooked teeth, rotated teeth, redundant teeth, stuck teeth, hidden teeth, misplaced teeth, deformed teeth are common features in class I malocclusion 1.3.2 Indicators on cephalometric radiographs 1.4 Treatment of class I malocclusion Extraction or not is a controversial issue in the history of orthodontics According to W Profit: The degree of deficiency is about 10mm: extraction Bowman asserted that there are many reasons to extract spacers in orthodontics such as crooked, deep Spee curve, deep bite, midline deviation etc The most important factor to determine is the patient 's profile Normally, the angle formed by the maxillary incisor and the lower mandibular incisor axis is 125-1310 Non-extraction treatment solutions: expansion, distalization, interproximal reduction Distalization: When choosing to distalize, the following factors should be considered: distance allowed to travel; correlation between the upper teeth and the jaws of the maxillary sinuses; ertical correlation: Open correlation is generally contraindicated for distal migration because it can cause an open bite and worsen facial elongation Interproximal reduction: commonly applied in adults, the size difference between the two jaws is a favorable factor in the decision of tooth grinding Interstitial grinding is only limited to the tooth enamel, the level of interstitial grinding allows each tooth to be about 0.5mm Expansion: If the posterior teeth are tilted inward with clinical presentation of posterior crossbite, this is a favorable factor Dilating the jaw area by 1mm will solve 1mm of crowding Orthodontic expansion can use dental or bone expansion methods 5 Beside dental dilators, use of self-ligating brackets and extension cords to widen the dental arch to the sides when placing the stopper in its original position or expanding the arch comes out first when placed on the side near the first small tooth 1.5 Self-ligating brackets 1.5.1 Definition: is a bracket system designed with a wire retention system right on the brackets, without the need for elastics or ligatures to hold the arch wire 1.5.2 The philosophy of the self-ligating bracket system: Light force is the key to self-ligating Light force, low friction helps teeth move physiologically without resisting the body and does not disrupt the blood vessels that nourish the area around the teeth 1.5.3 Classification of self-ligating brackets Self-ligating brackets are divided into two types: passive brackets and active brackets 1.5.4 Structure Just like normal brackets, including: bracket base, bracket body (including bracket wing, bracket slot and auxiliary components, only the difference is that there is an additional locking element to keep the arch wire in place used instead of elastic bands or metal ligatures) 1.5.5 Studies on self-ligating brackets In the world: According to research by Kiem et al., the use of self-ligating brackets in orthodontic treatment is increasing The first advantage of the self-ligating bracket system compared to the conventional bracket system is to reduce friction The study by Jahanbin et al showed that the adjustment time of self -ligating brackets was lower than that of traditional braces and the type of brackets did not affect the patient 's pain sensation According to Al-Ibrahim et al announced in 2021, using self-ligating brackets helps to reduce treatment time by 25 % compared to using traditional brackets The study of Maltagliati LA and Jiang RP et al (2008) using Damon's self-ligating bracket system and Damon's extension cord showed that the width in the denture area increased after treatment Vietnam: No studies on self-ligating brackets have been reported 1.6 Archwire Definition: The archwire is the main force-generating material in orthodontics, either by attaching to the brackets or can be placed outside the brackets Classification of archwires: There are many ways to classify archwires, archwires can be classified by: shape (triangle, oval, square); Metal components in the wire core (stainless steel metal wire, Themaloy, NiTi wire, Betatitanum); Dimensions (0.012inch; 0.013inch; 0.014inch; 0.016inch; 0.16 x 0.22 inch, ); Fabrication materials (metal wire, non-metallic wire, fiber reinforced composite bowstring ) Broader archwires: A new type of Nitium string developed by Ormco in 1994 called Copper Nitium, by adding a copper amount of about % and a small amount of Chromium (0.2-0.5) %) into a Nitium alloy, which helps to increase the ductility and elasticity of the wire, called superelastics Copper Nitium wire is usually made in the form of a wide arc, used for self-ligating brackets for the purpose of widening the arc CHAPTER RESEARCH SUBJECTS AND METHODS 2.1 Research object Subjects of the study are patients who come for examination and treatment at National Hospital of OdontoStomatology, Hanoi, are Vietnamese people, Kinh ethnic group 2.1.1 Selection criteria: Vietnamese people voluntarily participate in the study; Diagnosed with Class I Angle malocclusion with: Permanent teeth, with one or more crowded teeth, degree of deficiency < 10mm, Angle of nose and lips: 97,410 ± 8,000 (female), 91,670 ± 7,550 (male), Interlock angle: 119,740 ± 7,810(female), 121,440 ± 7,720(male) 2.1.2 Exclusion criteria: Congenital malformations in the maxillofacial region, permanent missing teeth (excluding the third molars); Patients with indications for orthopedic surgery; Patients with mental disorders; Patients with periodontal disease; The patient did not consent to participate in the study 2.2 Research Methods _ 2.2.1 Study design: Cross-sectional descriptive study for objective and non-controlled clinical intervention study, evaluating the results before and after for objective 2.2.2 Study sample size Apply the formula to calculate the sample size based on the success rate of the treatment ( ) n = Z 1- α /2 n: Study sample size Z 1- α /2: Number of standard error from mean (confidence coefficient), with α = 0.005 we have Z 1- α /2 =1.96 d: Desired accuracy, choose d = 0.1 Success rate of orthodontic treatment according to Kerr: p =89% Applying into the formula we get n = 38 2.3 Time and place of study The study was conducted from October 2016 to January 2023 Location: Orthodontic Department - National Hospital of Odonto-Stomatology, Hanoi, 108 Institute of clinical medical and pharmaceutical science 2.5 Steps for procedure 2.5.1 Step 1: Examination and diagnosis The patient is classified as occlusal, if there is a class I malocclusion, treatment is indicated without extraction, then proceed to step 2.5.2 Step 2: Introduce, invite to participate in the study Patients (or representatives of children