METHOD FOR DIAGNOSING DENTITION ANOMALY IN SAGITTAL DIRECTION ON JAW MODELS IN PERMANENT OCCLUSION

摘要

FIELD: medicine.;SUBSTANCE: method involves taking imprints from upper and lower jaw for manufacturing plaster jaw models. The lower jaw plaster model is used for measuring mesiodistal dimensions of twelve teeth: 46-41 and 31-36. Particular tooth lacking, its dimensions are calculated using percent proportions from mean dental parameter values table. Individual general projection length norm is calculated for upper and lower jaw using formulas; Lp_o=0.39*Σ₁₂ and Lp_u=0.35*Σ₁₂, where Lp_o and Lp_u are the individual general projection length norms of lower and upper jaw, respectively; 0,39 and 0,35 are indices describing relationship binding mean general projection length of lower and upper jaw to mean sum of mesiodistal dimensions of twelve teeth(46-41 and 31-36) of lower dental row in persons having physiological occlusion and permanent teeth dimensions within the limits of mean values, respectively; Σ₁₂ is the sum of mesiodistal dimensions of twelve teeth(46-41 and 31-36) measured on plaster model. Individual norm values of general upper and lower jaw projection length are compared to corresponding actual values measured on models. The values coinciding, conclusion is drawn concerning normal sagittal dimensions of denture. Difference being positive, increase in sagittal denture dimensions is considered to be the case. The difference being negative, reduction of sagittal denture dimensions is considered to be the case. Actual projection length values of the anterior segment are additionally determined by taking measurements from upper and lower jaw models, with distance between mesial point on labial approximal surface of incisor in vestibular position and point of intersection of line joining contact points of canine tooth and the first molar on the left and right side to median line of the upper jaw. Distance between contact point of lower central incisors cutting surfaces and point of intersection of line joining contact points of the first and the second premolars on the left and right side to median line of the lower jaw. Individual general projection length norms are calculated for upper and lower jaw anterior segment using formulas: lp_o=0.16*Σ₁₂ and lp_u=0.17*Σ₁₂, where lp_o and lp_u are the individual general projection length norms of lower and upper jaw anterior segment, respectively; 0,16 and 0,17 are indices describing relationship binding mean general projection length of lower and upper jaw anterior segment to mean sum of mesiodistal dimensions of twelve teeth(46-41 and 31-36) of lower dental row in persons having physiological occlusion and permanent teeth dimensions within the limits of mean values, respectively; Σ₁₂ is the sum of mesiodistal dimensions of twelve teeth(46-41 and 31-36) measured on plaster model. Individual norm values of general upper and lower jaw anterior segment projection length are compared to corresponding actual values measured on models. The values coinciding, conclusion is drawn concerning normal sagittal dimensions of denture. Difference being positive, increase in sagittal dimensions of anterior denture segment is considered to be the case. The difference being negative, reduction of dimensions of anterior denture segment is considered to be the case.;EFFECT: enhanced effectiveness in detecting denture anomalies in sagittal direction.;2 cl, 4 tbl