前牙美學(xué)之牙齦生物型

1、Anterior dental aesthetics:Gingival perspectiveThin periodontal biotypePeriodontal biotype is classified as thin, normal or thickThick periodontal biotype1. Thin periodontiumthickness of attached gingivalless than 1 mm, width3.55 mm, thin marginal bone2. Thick periodontiumthickness of attached gingi

2、val to1.3 mm, width 56 mm and more, thick marginal boneThe thick biotype with its flattened gingival soft tissue form tends to be more frequent with it occurring in 85% of the population than the thinbiotype with its scalloped tissue form (15% of thepopulation).Characteristics of thin biotype (a) Hi

3、ghly scalloped soft tissue and bony architecture(b) Delicate friable soft tissue(c) Minimal amount of attached gingiva(d) Thin underlying bone characterized by bony dehiscence and fenestration(e) Reacts to insults and disease with gingival recessionCharacteristics of thick biotype (a) Relatively fla

4、t soft tissue and bony architecture(b) Dense fibrotic soft tissue(c) Relatively large amount of attached gingiva(d) Thick underlying osseous form(e) Relatively resistant to acute trauma(f) Reacts to disease with pocket formation and infrabony defectformationFirstly, the thin gingival margins allow v

5、isibility of a metal substructure.Secondly, due to the fragility of the thin tissue, delicate management is essential for avoiding recession and hence visibility of subgingivally placed crown margins at the restoration/tooth interfacea thin biotypethe degree of interproximal fill is also dependant o

6、n the periodontal biotype A thick periodontal biotype encourages interdentalfill, while a thinner tissue type creates un-aesthetichollow gingival embrasures.For thick biotypes, the papilla may be established to normal dimensions of 5 mm, but for thin biotypes, it is difficult to recreate a papilla l

7、onger than 4 mm from the osseous crestThe 5 mm rule is only applicable for adjacent natural teeth or implants bounded by natural dentition. “5 mm rule”Normal scallop periodontal bioformHigh scallop periodontal bioformLow or flat scallop periodontal bioformPeriodontal bioforms are categorised into th

8、ree basic gingival scallop morphologiesCause?With a low scallop, the interproximal bone is thin, and the interproximal gingival contour nearly parallel to the underlying bone contour.The normal is advantageous for implant therapy since the bone has a congruous relationship with the FGM and is less p

9、rone to post-surgical recession.With a high scallop, the interproximal bone is wider, but the disparity between the bone contour and the FGM is problematic for favourable aesthetics (due to possible recession and creation of lack triangles) followingimplant or restorative procedures.TOOTH MORPHOLOGY

10、Tooth morphology determines two aspects of gingival undulationsFirstly, the basic tooth forms: circular, square or triangular, determine the degree of gingival scallop.Circular (oval) or square teeth produce a shallower gingival scallop, while triangular teeth form the opposite, a pronounced scallop

11、black triangles, especially with a thin biotype which has a propensity for recession, thicker interproximal squarer teeth yield better interproximal papilla maintenancedue to a smaller interproximal distance from theosseous crest to the FGM.For square-shaped teeth with wide contact points, the chanc

12、es of black triangles is minimal compared with triangular teeth having narrow, more incisally positioned contact pointsSecondly, the convex acuity of a tooth circumference influences the coronal/apical position of the FGMconvex tootha concave shapeTOOTH POSITION AND GINGIVALPROGRESSIONAltered passive eruption on the maxillary right lateral incisorBucally placed maxillary left lateral incisor with an a