Clinical implication: The purpose of this study is to record the vertical distance between anterior attachment of lingual frenum and incisal edge of mandibular central incisors in dentulous subjects and then determine the mean vertical distance and to suggest guidelines for positioning of mandibular central incisors in complete dentures.
Method: In this study, 150 dentulous subjects (75 males and 75 females) were chosen based on predecided inclusion criteria. A mandibular cast was obtained from irreversible hydrocolloid impression in modified stock trays for each subject. All subjects were instructed to elevate the tongue while the impressions were made. The vertical distance between the anterior attachment of the lingual frenum and incisal edges of mandibular central incisors was measured on the casts and then the values were statistically analyzed.
Result: The distance between anterior attachment of lingual frenum (AALF) mesioincisal edge of mandibular central incisor (CI) in male, female and total (male + female) subjects was measured. In males it ranged from 7.3 to 8.9 mm with mean (±SD) 8.29 ± 0.36 mm while in females it ranged from 7.1 to 9.0 mm with mean (±SD) 8.21 ± 0.38 mm.
Conclusion: It is believed that the application of this anatomic relation can provide a reliable point for arranging and checking the position of the mandibular central incisors for complete dentures in patients with class I ridge relationship.
Keywords: Complete denture; Edentulous; Lingual frenum; Mandibular central incisors.