Maxillomandibular Fixation The Jaw-Dropping Experience of a Lifetime

Our TeamFrom left to rightEmily Maslonkowski (BSAC)Ashley Phillips (Co-Team Leader) Nina Lewis (Co-Team Leader)Sara Karle (BWIG)Joe Ferris (Communications)

ClientJeremy Warner, MDPlastic Surgery, UW Medical School

AdvisorWilliam MurphyAssistant Professor, Department of Biomedical Engineering

OutlineBackground InformationProblem StatementMotivationOur Clients RequirementsDesigns for ProjectDecision MatrixGoals for ProjectQuestions

Background InformationMandible is the second most fractured bone of the faceCommon causes of fractured mandiblesAssaultMotor vehicle accidentsFallsSporting accidents3 steps in fixing a mandible: realign bones, fixation, and rehabilitation

Problem StatementDesign 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 ProjectSurgeons throughout history have dealt with broken mandibles in many waysMaxillomandibular fixation is outdatedrequires wiring the mouth shut with the use of arch bars and wiresMust be a better way!

Our Clients RequirementsCost effectiveLight weightDynamicEmergency releaseNo forces on front teethTime EffectiveSafe

Design #1: External StabilizationPlace support on head

Tighten straps securely

Design #1: Materials and CostsJaw brace

Estimated Price$70

Design #1: EvaluationProsEasy applicationCost effectiveQuick releaseNo anesthesia

ConsAestheticsDiscomfortSmall chance of sliding off

Design # 2: Screws and MagnetsFigure 1Figure 2Figure 3Magnets attached to screwsDrill screws into jawUse magnetic force to hold jaw together

Design #2: Materials and Costs4 Titanium Cortical Screws4 AlNiCo MagnetsCentre Drive Hexagonal Screwdriver (one-time cost)

Estimated Cost...$103.36-$110.56 per application

Design #2: EvaluationProsRe-usable materials (screws)Quick ApplicationDurable

ConsNo emergency releaseNot aesthetically pleasing Requires anesthesia

Design #3: Braces Apply brackets Connect lateralbrackets with elastic Connect vertical bracketswith rubber bands

Figure 2Figure 1

Design #3: Materials and Costs16 (stainless steel) brackets16 elastics (power chain) adhesive 8 rubber bands

Estimated Cost$400 per application

Design #3: EvaluationProsQuick releaseShort application time (approx. 15-20 minutes)No anesthesia necessaryAesthetically pleasing

ConsExpensive

Decision MatrixScale: 1-5, 1=poor, 5=good

Design 1: ExternalDesign 2: Screws/MagnetsDesign 3: BracesApplication Time544Cost532Quick Release515Aesthetics125Comfort124Durability244Local Anesthesia515Total241729

Goals for the Rest of the SemesterFind muscle forces in jawTest design on model skullFind exact price of braces design

ReferencesGoldman, Kim E. "Mandible Fractures." Ask An Oral & Maxillofacial Surgeon. 2005. 8 Sept. 2005 . "Muscles of Mastication: Form dictates function; Function follows form." Nociceptive Trigeminal Inhibition - Tension Suppression System. 15 Sept. 2005 . Peltier, Jacques, comp. Mandible Fractures. 26 May 2004. UTMB Dept. of Otolaryngology. 11 Sept. 2005 . Prater, Michael E., comp. Mandibular Fractures. 27 Nov. 1996. UTMB Dept. of Otolaryngology. 20 Sept. 2005 . Stierman, Karen, and Byron J. Bailey. "Mandible Fractures." 14 June 2000. 10 Sept. 2005 .

ANY QUESTIONS?

It has been proposed to design a device which will essentially mimic the function of maxillomandibular fixation but be easier and faster to apply while maintaining an adequate cost of application. The device should also be safe for the patient during application and for the 4-6 weeks of healing. This device will make mandible treatment an easier process for both the surgeon and the patient.

For hundreds of years, surgeons have come up with different ways to heal a broken mandible. The current way, though ancient by todays technology, is called maxillomandibular fixation which requires wiring the mouth shut with the use of arch bars and wires. It seems that there must be a better way to go about creating a device which will take less time apply with little frustration on the part of the surgeon.

Cons: discomfort- external irritation, lack of hygiene Screws placed between the canine and the first pre-molar. Magnets have predrilled holes due to the easily manufactured AlNiCo magnets. Cortical Screws (2mm diameter, 10 to 16 mm thread length). Hole of magnet is less than 4mm diameter b/c head of screw is 4mm in diameter. Brackets are applied to the upper and lower, 1st and 2nd bicuspid and the 1st and 2nd molar on the left and right side These teeth are shown highlighted in yellow in figure 1. They are applied using an adhesive that can be applied to wet surfaces and it takes approximately 30 seconds to dry.Connect the lateral brackets using the power chain elastics Lastly connect the vertical brackets using rubber bands