13. Ulcers of local aetiology

20. Main topics CEJ--- Four tooth tissues Four types of teeth How to identify a deciduous or permanent tooth ? Gingival papillae and gingival sulcus Five groups of periodontal ligament Four type tongue papillae Four principal factors of causes for caries are dental plaque , host , sugar and time .

22. Definition : Dental plaque Calculus Classification of periodontal diseases

23. The width of opening mouth: 1.normal: 3.7cm permit three fingers insertion 2.slignht limitation of opening mouth: 2-2.5cm permit two fingers insertion 3.moderate limitation of opening mouth: 1-2cm permit one fingers insertion 4.severe limitation of opening mouth: <1cm one finger cannot insert 5.complete limitation of opening mouth: mouth cannot pen The mobility of the tooth: 1-degree the mobility of the tooth is within 1mm 2-degree the mobility of the tooth is between 1-2mm 3-degree the mobility of the tooth is more than 2mm or vertical loose

24. The occluding relation: 1.Central occlusion: In central occlusion, the line between upper and lower central incisors should be in the same sagittal plane; upper teeth exceed the outer space of the lower teeth; upper teeth overlap the lower teeth within one third of labial height; the horizontal distance between upper and lower teeth is less than 3mm. 2.Counter bite : the lower teeth exceed the outer space of the upper teeth. 3.Edge to edge bite : the upper and lower teeth incisal edge is touched 4.Open bite : the upper and lower teeth are partly a parting 5.Deep over bite :the upper teeth exceed the outer space of the lower teeth; upper teeth overlap the lower teeth more than one third of labial height; the horizontal distance between upper and lower teeth is more than 3mm