An Evaluation of a Noninvasive Method of Assessing Alveolar Bone Levels in an Experimental Model of Cleft Lip and Palate

OBJECTIVE: The purpose of this study was to evaluate an ultrasound mucous-membrane-thickness-measuring device as a noninvasive, nonionizing alternative to radiography in the assessment of alveolar bone grafting. DESIGN: This was a prospective experimental study on porcine cadaver models. METHOD: An ultrasound technique (Krupp SDM) was assessed ex vivo on three specially developed porcine cadaver models in comparison to radiography and ridge-mapping. Direct measurement of the mucosal thickness provided a standard for comparison. In each model, 30 measurement sites were identified for comparison of the techniques. RESULTS: All measurement techniques demonstrated clinically acceptable reproducibility. Of the clinical measurement techniques, radiography proved to be the most reliable, showing a small, nonsignificant statistical difference from direct measurement. Both the ultrasound technique and ridge-mapping showed significant tendencies to underestimate mucosal thickness that became greater with increasing mucosal thickness. At sites where mucosal thickness was less than 6 mm, the ultrasound technique underestimated mucosal thickness by 0.6 mm on average. At sites where mucosal thickness exceeded 6 mm, ultrasonic artifacts rendered the ultrasound technique unreliable. CONCLUSION: The ultrasound technique could prove to be a useful clinical adjunct to radiography in the assessment of alveolar bone grafts, but in this particular application, care should be taken when using it to assess deeper alveolar defects.