Maxillomandibular Fixation “The Jaw-Dropping Experience of a Lifetime”

Our Team From left to right… Emily Maslonkowski (BSAC) Ashley Phillips (Co-Team Leader) Nina Lewis (Co-Team Leader) Sara Karle (BWIG) Joe Ferris (Communications)

Client Jeremy Warner, MD  Plastic Surgery, UW Medical School

Advisor William Murphy  Assistant Professor, Department of Biomedical Engineering

Outline Background Information Problem Statement Motivation Our Client’s Requirements Designs for Project Decision Matrix Goals for Project Questions

Background Information Mandible is the second most fractured bone of the face Common causes of fractured mandibles 1.Assault 2.Motor vehicle accidents 3.Falls 4.Sporting accidents 3 steps in fixing a mandible: realign bones, fixation, and rehabilitation

Problem Statement Design a device which will:  Fixate the top of the mouth to the jaw  Be easier and faster to apply  Maintain an adequate cost of application  Be safe for the 4-6 weeks of healing

Motivation for Project Surgeons throughout history have dealt with broken mandibles in many ways Maxillomandibular fixation is outdated  requires wiring the mouth shut with the use of arch bars and wires Must be a better way!

Our Client’s Requirements Cost effective Light weight Dynamic Emergency release No forces on front teeth Time Effective Safe

Design #1: External Stabilization Place support on head Tighten straps securely

Design #1: Materials and Costs Jaw brace Estimated Price…$70

Design #1: Evaluation Pros Easy application Cost effective Quick release No anesthesia Cons Aesthetics Discomfort Small chance of sliding off

Design # 2: Screws and Magnets Figure 1 Figure 2 Figure 3  Magnets attached to screws  Drill screws into jaw  Use magnetic force to hold jaw together

Design #2: Materials and Costs 4 Titanium Cortical Screws 4 AlNiCo Magnets Centre Drive Hexagonal Screwdriver (one-time cost) Estimated Cost...$ $ per application

Design #2: Evaluation Pros Re-usable materials (screws) Quick Application Durable Cons No emergency release Not aesthetically pleasing Requires anesthesia

Design #3: Braces Apply brackets Connect lateral brackets with elastic Connect vertical brackets with rubber bands Figure 2 Figure 1

Design #3: Materials and Costs 16 (stainless steel) brackets 16 elastics (power chain) adhesive 8 rubber bands Estimated Cost…$400 per application

Design #3: Evaluation Pros Quick release Short application time (approx minutes) No anesthesia necessary Aesthetically pleasing Cons Expensive

Design 1: ExternalDesign 2: Screws/Magnets Design 3: Braces Application Time 544 Cost532 Quick Release515 Aesthetics125 Comfort124 Durability244 Local Anesthesia 515 Total Scale: 1-5, 1=poor, 5=good Decision Matrix

Goals for the Rest of the Semester Find muscle forces in jaw Test design on model skull Find exact price of braces design

References Goldman, Kim E. "Mandible Fractures." Ask An Oral & Maxillofacial Surgeon Sept "Muscles of Mastication: Form dictates function; Function follows form." Nociceptive Trigeminal Inhibition - Tension Suppression System. 15 Sept Peltier, Jacques, comp. Mandible Fractures. 26 May UTMB Dept. of Otolaryngology. 11 Sept Prater, Michael E., comp. Mandibular Fractures. 27 Nov UTMB Dept. of Otolaryngology. 20 Sept Stierman, Karen, and Byron J. Bailey. "Mandible Fractures." 14 June Sept

ANY QUESTIONS?