NASAL ALVEOLAR MOLDING tài liệu, giáo án, bài giảng , luận văn, luận án, đồ án, bài tập lớn về tất cả các lĩnh vực kinh...
PRESURGICAL ORTHOPAEDIC NASOALVEOLAR MOLDING DR LE THANH BINH DR TRAN VINH HUNG CONTENTS I INTRODUCTION Nasoalveolar molding (NAM) Nasoalveolar molding works Nasoalveolar molding goals II RESEARCH III CONCLUSION I INTRODUCTION Cleft lip and palate can present with considerable variation in severity and form These clefts, deficient in both hard and soft tissue elements, present a significant surgical challenge to the achievement of a functional and cosmetic outcome The affected lower lateral nasal cartilage results in a depressed dome, the appearance of an increased alar rim, an oblique columella columella, and an overhanging nostril apex There have been numerous techniques documented over the centuries to improve the position of the cleft alveolar segments such as Hoffman (1968) and Georgiade (1975) In 1993, Grayson adapted his nasal stent to extend from the anterior flange of an intraoral molding plate This new technique was called nasoalveolar molding (NAM) What is nasoalveolar molding (NAM (NAM)? Nasoalveolar molding (NAM) is a nonsurgical way to reshape the gums, lip and nostrils with a plastic plate before cleft lip and palate surgery Uses of NAM: It reduces the cleft inside the mouth It reduces the gap in the upper lip It lifts and narrows the nose NAM is used mainly for children with large or wide clefts, and has greatly changed cleft repair Nasal stent added to the intraoral molding plate How does NAM work? NAM is used the best at the first few months after birth, when these tissues are soft and easy to mold The baby wears the molding plate 24 hours a day, days a week, including when they are feeding Every to weeks, the orthodontist makes small changes to the shape of the molding plate to guide the baby’s gums as they grow Once the gap in the gums is small enough, the orthodontist adds a nasal stent covered with smooth, rounded plastic to the front of the molding plate plate It slowly lifts up the nose and shapes the nostril on the side of the cleft The design of the nasal stent and the position of the nasal stent in the nostril Initial impression of the cleft lip and palate infant A Infant held in an inverted position during the impression process to prevent the tongue from falling back and to allow fluids to drain out B Impression of a unilateral cleft patient using a custom tray & heavy-body silicone impression material C Plaster stone working model of a bilateral cleft patient for appliance fabrication D Bilateral nasoalveolar molding plate with retention buttons fabricated using self-cure acrylic resin A Broader base tapes secured onto the infant’s cheeks B Orthodontic elastics incorporated into loops of thinner tapes C Thinner tapes secured to the base tapes with backward and upward pull D Lip taping to approximate the alveolar segments in midline Journal of Prosthodontic Reseach 57 (2013) 224-231 Presurgical nasoalveolar molding in reducing severity of the initial cleft deformity A Patient before implementation of nasoalveolar molding B Patient after nasoalveolar molding and just before primary surgical repair C Frontal view and (D) base view of a patient at years, months of age showing a minimally detectable lip scar and good nasolabial esthetics A The nasal stent B Hard acrylic is applied C The hard acrylic nasal stent is coated with a thin layer of soft denture liner for comfort D The upper lobe of the nasal stent enters the nose and gently lifts the dome The lower lobe of the nasal stent lifts the nostril apex and defines the top of the columella A Bilateral complete cleft with nearly absent columella, wide nasal tip, everted premaxilla, and widely separated lip segments B The bilateral nasoalveolar molding plate appliance C Appliance NAM to infant D After months of NAM therapy and before the primary surgical repair E Patient at year, months of age Benefits Short-term Achieve a better and more predictable outcome with less scar tissue formation Long-term The change in nasal shape is stable with less scar tissue and better lip and nasal form This improvement reduces the number of surgical revisions for excessive scar tissue, oronasal fistulas, nasal, and labial deformities (A) Before the initiation of NAM and the associated surgical technique (B) After the introduction of NAM and presurgical columella elongation Typical results in infants treated before month of age (a) (b) (a) and (b) Before initiation of NAM Child’s age 21 days (c) (d) (c) and (d) After completion of NAM Typical results in infants treated before month of age (cont.) (e) (f) (g) (e) and (f) At 18 months of age (g) Progressive changes in alveolar morphology following NAM COMPLICATIONS Irritation of the oral mucosal or gingival tissue Common areas of breakdown are the frenum attachments, the anterior premaxilla, or the posterior fauces as the molding plate is retracted Besides, cheeks are the most common area of tissue irritation irritation Poor compliance by the parents can cause loss ... http://allfreehere.ucoz.com http://booksandsofts.googlepages.com The ZEN can be used to improve moulding efficiency by warming up the molding machine before the work shift starts. This allows molding work to begin immediately at the start of the work shift. When work shifts vary, pre-set weekly timers can be selected using a switch. ■System Configuration ■Program Example ■Parameter Settings [...]... Best to design runners as small as possible… Example:if the runner diameter is increased from ¼ in to 5/16 in.; the percentage increase in material flow is 60 % However, too small a runner require higher injection pressure and may cause surface defects on parts Runner Length Best to design runners as short as possible to reduce heat and pressure losses Fillet radius (min 1/8”) a must at the intersection... gate blush, the gates should be located at right angles to the runner (Figure 1-10) • Direct gating to a cosmetic surface may cause surface imperfections It is suggested that direct gates not be used in molding reinforced resins into rectangular shapes Fiber orientation may result in part distortion GATE LOCATED RIGHT ANGLE TO THE RUNNER HELPS WITH MELT HOMOGENIZATION, VENT OUT GASES THROUGH RUNNERAND... hours Total $ amount savings: 166 x 35 = $ 5810 Total $ amount saved: (10 Machine shop) 58,100 Benjamin Franklin once said “Beware of little expenses; a small leak can sink a great ship.” Mold cooling Molding Cycle…….80% is cooling time Mold cooling Wall thickness 0.150 0.300 Cooling Time 45 sec 210 sec International Journal of Mechanical Sciences 48 (2006) 430–439 A systematic computer-aided approach to cooling system optimal design in plastic injection molding H. Qiao à Cardiff School of Engineering, Queen’s Buildings, The Parade, PO Box 925, Cardiff, CF24 0YF, UK Received 10 December 2003; received in revised form 10 October 2005; accepted 10 November 2005 Available online 27 December 2005 Abstract Cooling system design is of great importance for plastic injection molding because it significantly affects the productivity and quality of the final products. In this paper, a systematic computer-aided approach is developed to achieve the cooling system optimal design. This approach expiates the trial and error process normally practiced in conventional cooling system design based on the designer’s experience and intuition. Various aspects of the optimization process for cooling system design are investigated including cooling analysis using boundary element method (BEM), a perturbation-based approach to design sensitivity analysis, optimization problem formulation, and a novel hybrid optimizer based on Davidon–Fletcher–Powell (DFP) method and simulated annealing (SA). A case study shows that the proposed methodology for cooling system optimal design is efficient, robust and practical. r 2005 Elsevier Ltd. All rights reserved. Keywords: Boundary element method; Cooling system design; Perturbation-based approach; Simulated annealing 1. Introduction The injection molding cycle consists of several stages, such as filling, packing, and cooling. The cooling system design is of considerable importance since about 80% of the cycle time is taken up by the cooling phase. The cooling system must be able to remove the heat at the required rate so that the plastic part can be ejected without distortion. At the same time, the cooling of the part should be kept as uniform and balanced as possible so that undesired defects such as sink marks, differential shrinkage, internal thermal residual stress and warpag e can be reduced. In cooling system design, design variables typically include the size, location and layout of cooling c hannels, and the thermal properties, temperature and flow rate of the coolant. With so many design param eters involved, design work to determine t he optimum c ooling s ystem is e xtremely difficult. Traditionally, the designer uses his experience and intuition to guide the design process. This manual design process has the advantage that the designer’s judgement can be utilized for the design. However, as the design problem becomes more complex, the manual d esign process based only on t he designer’s judgement becomes inadequate and even impossi- ble. For an optimum design, the designer needs a more powerful tool integrating the cooling analysis and optimization programs into the design process. Using such a tool, a design can be improved systematically, automatically and efficiently. The analysis of heat transfer within the mold and the part plays a crucial role in the optimum cooling system design. Since the mold usually has a complicated structure with runners and cooling channels, more efforts have been made on the mold cooling analysis. There are mainly two approaches considered for the mold cooling analysis: cycle- averaged approach and transient approach. In cycle-averaged approach, the mold thermal analysis is based on the steady-state heat transfer approximation for the cycle-averaged temperature field during the J Oral Maxillofac Surg 67:2222-2231, 2009 Postoperative Nasal Forms After Presurgical Nasoalveolar Molding Followed by Medial-Upward Advancement of Nasolabial Components With Vestibular Expansion for Children With Unilateral Complete Cleft Lip and Palate Norifumi Nakamura, DDS, PhD,* Masaaki Sasaguri, DDS,† Etsuro Nozoe, DDS, PhD,‡ Kazuhide Nishihara, DDS, PhD,§ Hiroko Hasegawa, DDS, PhD,ʈ and Seiji Nakamura, DDS, PhD¶ Purpose: The management for primary unilateral cleft lip nose deformities has not yet been estab- lished In this study, short-term postoperative nasal forms after presurgical nasoalveolar molding (NAM) followed by primary lip repair for children with complete unilateral cleft lip and palate (UCLP) were evaluated and compared with the nasal forms achieved by treatment without nose correction Patients and Methods: Fifteen patients with complete UCLP who were treated in our department and followed up for more than year (range to yrs) were enrolled All subjects underwent presurgical orthopedic treatment with NAM, followed by lip repair using Cronin’s triangular flap method with medial-upward advancement of nasolabial components with vestibular expansion Postoperative nasal forms including nostril height and width ratio, ratio of the height of the top of the alar groove, and curvature of the appropriate circle of the nasal ala were evaluated using color photographs Fifteen patients with complete UCLP who underwent presurgical orthopedic treatment using a Hotz plate followed by lip repair without nose correction served as controls Results: The comparison of postoperative nasal forms demonstrated that the nostril height and width ratio and the height of the top of the alar groove in the correction group were significantly superior compared with those of the controls Conclusions: Our management of cleft lip nose will provide good nasal forms with minimum invasion in patients with UCLP Long-term follow-up will be necessary to clarify effects on the growth of nasal tissues reconstructed in infancy © 2009 American Association of Oral and Maxillofacial Surgeons J Oral Maxillofac Surg 67:2222-2231, 2009 *Professor, Department of Oral and Maxillofacial Surgery, Field of Maxillofacial Rehabilitation, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan †Assistant Professor, Division of Oral and Maxillofacial Diagnostic and Surgical Sciences, Kyushu University, Graduate School of Dental Science, Kyushu, Japan ‡Associate Professor, Department of Oral and Maxillofacial Surgery, Field of Maxillofacial Rehabilitation, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan §Senior Assistant Professor, Department of Oral and Maxillofacial Surgery, Kagoshima University, Medical and Dental Hospital, Kagoshima, Japan ʈAssistant Professor, Department of Pediatric Dentistry, Field of Developmental Medicine, Kagoshima University, Graduate School of Medical and Dental Sciences, Kagoshima, Japan ¶Professor, Division of Oral and Maxillofacial Diagnostic and Surgical Sciences, Kyushu University, Graduate School of Dental Science, Kyushu, Japan Address correspondence and reprint requests to Dr Nakamura: Department of Oral and Maxillofacial Surgery, Field of Maxillofacial Rehabilitation, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1, Sakuragaoka, Kagoshima 88908544, Japan; e-mail: nakamura@denta.hal.kagoshima-u.ac.jp © 2009 American Association of Oral and Maxillofacial Surgeons 0278-2391/09/6710-0022$36.00/0 doi:10.1016/j.joms.2009.04.098 2222 2223 NAKAMURA ET AL Despite recent developments in cleft surgery, the surgical modality for primary correction of unilateral cleft lip nose has not yet been established It was previously thought that correction of the nose should be postponed until nasal development is complete Consequently, these children suffer a good deal of embarrassment regarding their appearance during childhood and puberty.1 Sugihara et ...CONTENTS I INTRODUCTION Nasoalveolar molding (NAM) Nasoalveolar molding works Nasoalveolar molding goals II RESEARCH III CONCLUSION I INTRODUCTION Cleft... intraoral molding plate This new technique was called nasoalveolar molding (NAM) What is nasoalveolar molding (NAM (NAM)? Nasoalveolar molding (NAM) is a nonsurgical way to reshape the gums,... RESEARCH Presurgical nasoalveolar molding in reducing severity of the initial cleft deformity A Patient before implementation of nasoalveolar molding B Patient after nasoalveolar molding and just before