Intraoral versus extraoral measurement of the height of the interproximal contact area in maxillary anterior teeth.

OBJECTIVES: This study aimed to clinically quantify the apicoincisal height of the upper interproximal areas directly in patients' mouths compared to measurements on stone models. SUBJECTS AND METHODS: One hundred and fifty participants (75 females and 75 males, age range 20-45 years) were recruited for this study. A digital caliper was used to measure the anterior maxillary interproximal contact areas directly in patients' mouths and on stone models. The digital caliper accuracy was up to 0.01. The Statistical Package for Social Sciences software (SPSS, version 19.0, Chicago, Ill., USA) was used for statistical analysis. Statistical significance was based on probability values <0.05. RESULTS: The intraoral measurement of proximal contacts as well as the measurement on stone models showed that the dimensions of interproximal contacts on both sides of each tooth were significantly different (p < 0.001) and that the dimension of the mesial contact point was larger than that of the distal contact point of each tooth. The largest contact point was the one between the central incisors (direct intraoral measurement = 2.9-6.49 mm; model measurement = 3.31-6.91 mm). On the other hand, the contact point between the canine and first premolar was the smallest on both sides of the arch (0.63-2.52 mm intraorally, 0.98-2.88 mm on models). The intraoral measurement of contact points was more accurate than model measurements, and the differences were statistically significant (p < 0.001). CONCLUSIONS: The clinical evaluation of contact point dimensions using a digital caliper was more precise than measuring contact points on stone models; hence, it is a viable, quick and adequate method to be used routinely.