Davis Nasal Projectometer

Davis Nasal Projectometer — Nasal Projection Measurement for Rhinoplasty

BusinessMed® Davis Nasal Projectometer is an eponymous rhinoplasty measuring instrument in the Measuring & Marking Instruments category, developed with Richard Davis MD. Used by plastic surgeons and ENT specialists, it quantifies nasal tip projection, radix height, rhinion, and nasolabial angle at the columellar-labial junction — providing metric-based data for preoperative planning and intraoperative verification.

Dual-axis X-Y calibration with independent thumb screw adjustment at four measuring points allows each pin to lock onto its assigned nasal landmark independently. This establishes a rigid three-point coordinate plane — forehead base, dental stop, and nasal landmark — that remains geometrically consistent between sequential pre- and postoperative assessments.

The dental stop anchors the instrument to the maxillary midline, eliminating parallax error by creating a fixed external reference independent of the nasal structures being measured. The notched forehead base locks to the glabellar midline, ensuring reproducible repositioning across multiple assessments within the same procedure or across longitudinal follow-up appointments.

Clinical Uses & Applications

• Nasal tip projection measurement at the columellar-labial junction during preoperative rhinoplasty planning
• Radix and rhinion height quantification during intraoperative dorsal reduction verification in open rhinoplasty
• Nasolabial angle measurement at the anterior nasal spine during rhinoplasty tip refinement
• Nasal projection baseline establishment before and after tip graft placement in reconstructive rhinoplasty
• Columellar-labial junction projection tracking during revision rhinoplasty for longitudinal outcome comparison
• Nasal dimension assessment during ENT septal reconstruction and functional rhinoplasty procedures

Associated Instrumentation

• Castroviejo Calipers perform localized nasal measurements before Projectometer establishes overall projection baseline
• Davis Nasal Projectometer establishes four-point metric baseline and verifies postoperative projection change in millimeters
• Aufricht Nasal Retractor exposes nasal anatomy after Projectometer measurements confirm the reduction target
• Joseph Saw or osteotomes execute the bone reduction indicated by Projectometer measurement findings

Technical Reference

Davis Projectometer vs Castroviejo Caliper Stability Distinctions

Castroviejo Calipers are floating instruments subject to parallax error during repeated positioning. The Davis Projectometer creates a rigid three-point stable plane via the dental stop and notched forehead base — the instrument itself becomes an external coordinate system that does not shift between measurements.

Fixed Coordinate System and Reproducibility Across Sequential Assessments

The dental stop anchors to the maxillary midline; the notched forehead base locks to the glabellar midline. These two fixed anchors create an external reference frame independent of nasal soft tissue. The same frame position is reproducible across pre-intraoperative, intraoperative, and postoperative measurement sessions.

Thumb Screw Resistance as Tactile Measurement Confirmation

Independent thumb screw resistance at each pin signals firm landmark contact without soft tissue compression. The surgeon detects the transition from compliant tissue resistance to firm cartilage or bone contact through the screw, indicating when the pin has reached the intended measurement depth.

Four Point Pin to Surgical Decision Mapping

Radix and rhinion pins quantify dorsal reduction targets before osteotomy. The tip-defining pin measures projection change after graft placement. The nasolabial pin records angle change at the columellar-labial junction. Each pin maps to a distinct surgical decision — not interchangeable between measurement phases.