Won Moon, DMD, MS Professor, Department of Orthodontics, Ajou University School of Medicine Adjunct Professor, The Forsyth Institute Adjunct Professor, Kyung Hee University School of Dentistry Former Thomas R. Bales Endowed Chair in Orthodontics, UCLA (2013-2020) Founder, the Moon Principles International Research Institute Co-Founder, BioTech Innovations Diplomate of the American Board of Orthodontics, since 2002

我記得第一次邀請Dr.Won Moon來台灣演講是2017年，不經不覺已經有六年時間，如今成年人上顎骨擴張已經被普遍使用。合併mini-screw上頷擴張的裝置非常多,但很多設計其實沒有基礎理論和研究報告，現在絕大多數醫師都是使用Dr. Moon 的MSE裝置，原因是非常多知名期刋文獻都証明其理論和實用性。個人認為expander的位置和mini-screws穿過兩層cortical bone 是其成功的關鍵。MSE除了可以用於治療上顎狹窄，另一臨床亮點是合併Face mask 治療安格氏第三類病人，而最新研究也証明MSE擴弓對airway有明顯影響。
因為新冠疫情的原故，Dr. Moon 已經三年多沒有來台灣，這次他將會帶來更多的研究成果、臨床治療的病例及MSE 使用protocol updated. 機會難逢，大家還不趕快佔位!

陸開盛

The latest developments with Midfacial Skeletal Expander (MSE): what we have learned after two decades of traveling uncharted territory.

The non-surgical Maxillary Skeletal Expander(MSE) has evolved since early 2000, and it's application has been growing globally. With the proliferation of MSE-related publications by multiple authors, there is clear evidence to support its impact.

The overview of the MSE utilization will be discussed. The dental and skeletal effects of maxillary expansion using the conventional rapid palatal expander(RPE),the surgically-assisted rapid palatal expander (SARPE), and the micro-implant assisted midfacial skeletal expander (MSE) will be illustrated. Dental expansion, bone bending, and true skeletal expansion will be compared. The adverse clinical consequences of RPE and SARPE in high-angle cases will be explored, and a new approach eliminating these problems by the use of MSE will be presented, based on research data. Clinical cases involving non-surgical midfacial expansion in both adolescent and adult patients will be examined in detail.

However, the success of MSE was not always predictable, especially for mature male patients. Over the last two decades, enormous efforts have taken place in attempts to further understand determining factors. Through clinical studies, computer simulations, and innovative treatment modifications, many of those challenging cases now can be safely treated without significant complications. During the two decades of journeying through the uncharted territory of non-surgical midfacial expansion in mature patients, not only have traditional paradigms been defied, but many initial MSE concepts have also required adjustment. Often, failures would result from misusing the appliance. In this presentation, various ways to accommodate patients with extremely thick or thin palatal bones, narrow palatal vault, massive zygoma, palatal torus, skeletal asymmetry, etc. will be discussed. Application of digital workflow in MSE fabrication and MSE modification could also enhance the success of MSE treatment in difficult cases. Furthermore, for extremely difficult cases, various minor surgical procedures that could aid MSE will be discussed. By applying these innovative protocols, the traditional SARPE can be largely eliminated. Although the outcomes of MSE treatment may notalways be predictable at this point in time, significant progress has been made by forward- thinking investigators, and the MSE technique will continue to evolve.

Clinical cases involving non-surgical midfacial expansion in both adolescent and adult patients will be examined in detail. Through these clinical examples, a proper MSE fabrication and updated expansion protocols will be illustrated. Secondly, other advantages of utilizing MSE will be demonstrated. Clinical cases and research findings illustrating the profound enlargement of nasal airways and functional improvements after MSE in both adolescent and adult patients will be closely evaluated. Furthermore, the airflow improvements will be illustrated by the dynamic airflow measurements directly from the patients and also by the computational fluid dynamics model simulations. The airway obstruction and the Obstructive Sleep Apnea Syndrome (OSAS) are related but the true impact of MSE for OSAS has not been clearly defined. The latest findings regarding the impact of MSE on OSAS will be presented.

MSE can also aidin orthopedic correction of Class III cases when combined with aprotraction device. The traditional orthopedic correction of Class III patients with RPE and facemask (FM) can often create unwanted dental movements: proclination of the incisors and buccal flare of the molars. By combining MSE with FM, a pure skeletal expansion and protraction is possible, eliminating and reversing these adverse dental side effects.The magnitude and the speed of correction are decisively greater and faster than with traditional treatment results. The high angle Class III problem can be managed with this approach using subsequent vertical correction. Clinical cases combining MSE and facemask(FM) in both growing and mature patients will be discussed, and orthopedic effects will be illustrated. The use of growth modification for young patients and distraction-like protraction techniques for mature patients, in conjunction with this new device, open the door to many new possibilities.

• Overall concept of MSE, Dx and T planning, and patient selection
• Craniofacial vs dentoalveolar changes with MSE
• Correct use of MSE: proper appliance fabrication and positioning, utilizing radiographic information and digital workflow
• New activation protocol based on mechanical and biological considerations
• Difficulty level assessment, and subsequent procedure or appliance design modifications for better outcomes
• Updated solution for patients with narrow palates
• Updated patients requiring multiple MSEs
• Asymmetric patients and asymmetric expansion
• Cortopuncture and MSE for challenging cases
• Minor surgical procedures for extremely difficult cases in order to avoid more invasive SARPE procedures
• MSE and airway changes
• MSE and maxillary protraction in both young and mature patients
• Troubleshootin