CMF Distractor
Scott P. Bartlett, Richard A. Hopper, Satyesh Parmar, Majeed Rana, Alberto A. Rocha Pereira
Fig 1: Mandible correction. 
Fig 2: Cranium expansion. CMF distraction is used for lengthening or bone transport to correct congenital deficiencies or acquired (posttraumatic, post-surgical or post-infectious) defects in the mandible (Fig 1) or the cranium (Fig 2). Gradual expansion allows for new bone formation and soft-tissue adaption both in pediatric and adult patients. With existing systems three main issues have raised concerns. The possibility of wrong-way activation of the system, the inadvertent movement by the system and difficult screw engagement and removal.
The new CMF Distractor is visually similar to the old system (Craniofacial Distraction System), except that the distraction bodies are approximatively 5 mm longer.
New ratcheting mechanism
The new CMF Distractor has a spring clip (detent tab) to avoid inadvertent reversed movement of the distractor. In addition, the new Patient Activation Instrument contains a one-way ratchet clicking when turned in the wrong direction. With these new features the distractor movement is well controlled and if used correctly will produce reliable results.
Fig 3: AB Body with footplates attached. 
Fig 4: BC Body with footplates attached. Raised Head Screws
In addition to the regular Plus-Drive Screws provided with the CMF Distractor, new Raised Head Screws are available for easier removal. These Raised Head Screws incorporate both a Hex-Drive and a Plus-Drive in the same screw head, with the Hex-Drive screwdriver having a tapered fit allowing for the same retention force as in the Plus-Drive system.
Fig 5: New Raised Head Screws. Planning and Performing Maxillo-Mandibular Distraction Osteogenesis
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