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https://youtu.be/HlVkae2bcNg?si=DVf-mInSeju4cmib اليشوف الفيديو يتم اهداءه ثواب قراءة سورة البقرة .

وهاي المعايدة خاف تتيهوها

What are Black Triangles? Black triangle is a space or a gap seen at the cervical embrasure, this creates triangular gap between the teeth and gums. It is seen when interdental gingiva doesn’t fully fill the void between teeth at gingival margin. Causes- 1. It happens with any method of alignment, therefore in orthodontic treatment it is a natural consequence of alignment correction. 2. Shape of teeth 3. Position of teeth 4. Gingival recession 5. Lack of papilla once teeth gets aligned after orthodontic treatment. Solution- 1. IPR (Interproximal reduction) can be done at point of contact to allow affected teeth to come together. 2.Restorative therapy- to fill small gaps by composites. 3.Reconstruction Periodontal therapy -known as gingival graft can be done ,to increase interdental papilla height and volume to fill the black triangle void.

Three types of gingival embrasure are seen: a) Type I: Embrasures are completely occupied by healthy interdental papilla. b) Type II: About 75% of embrasure is occupied by the gingiva. c) Type III: About 50% of the embrasure is occupied by gingival .

Embrasure space :- when adjacent teeth contact, the continuous space that surrounds each contact area can be divided into four separate triangular . Posterior teeth :- 🔻 facial ( buccal ) embrasure space 🔺️lingual embrasure space ➡️ larger than facial embrasure space. Anterior teeth :- 🔻incisal embrasure space 🔺️interproximal space ( cervical embrasure space or gingival embrasurespace ) ➡️ this space is completely filled with the interdental papilla in periodontally healthy person. 🔸️Embrasures surrounding well-formed proximal contact areas serve as spillways to direct food away from the gingiva. تبعد جزيئات الطعام عن اللثة

A diastema is a space that exists between two adjacent teeth in the same arch that is not the result of a missing tooth.

Incisal / occlusal view Anterior teeth ➡️ in middle third ( centered ) Posterior teeth ➡️ in middle third ( slightly buccal to center )

جدول يوضح contact areas of all teeth Note :- Contact areas are not normally located in the cervical third. _ On most teeth, the distal contact is more cervical than its mesial contact.

Upper central incisor جهه mesial تكون contact area بال incisal third اما بجهه distal تكون عند التقاء incisal و middle third

تعريف و وظيفة هسه نشوف وين موقع contact areas لكل سن

Contact areas ( or proximal height of contour ) are the greatest heights of contour or location of the greatest bulges on the proximal surfaces of tooth crowns, where one tooth touches an adjacent tooth. Floss must pass through contact areas to clean the proximal surfaces, which are otherwise inaccessible to the toothbrush. one tooth touches an adjacent tooth. يجب أن يمر الخيط بمناطق التلامس القوية لتنظيف الأسطح القريبة والتي لا يمكن الوصول إليها بواسطة فرشاة الأسنان . The proximal contact of each tooth with the adjacent teeth has important functions: 🔸️ The positive contact of all teeth within each dental arch stabilizes the position of teeth within each arch. 🔸️ Contact helps prevent food impaction which can contribute to decay and gum and bone disease ( periodontal disease). 🔸️ Contact protects the interdental papillae of the gingiva by diverting food buccally and lingually.

Proximal view of premolar buccal height of contour ➡️ cervical third lingual height of contour ➡️ middle third

هذا الجدول يوضح موقع height of contour بجهه facial كل الأسنان يكون بمنطقة cervical third اما بجهه lingual حسب الأسنان اذا anterior teeth يكون بال cervical third بمنطقة cingulum اما posterior teeth يكون بال middle third Note :- It is usually located in either the cervical third or the middle third (not normally in the occlusal or incisal third).

Height of contour ( crest of curvature ) on facial or lingual surface :- The shape and extent of the greatest bulge on the facial and lingual crown surfaces help determine the direction that food particles are deflected in as they are pushed cervically over the tooth surfaces during mastication. يساعد شكل ومدى الانتفاخ الأكبر على أسطح تاج الوجه واللسان في تحديد الاتجاه الذي تنحرف فيه جزيئات الطعام أثناء دفعها عنقيًا فوق أسطح الأسنان أثناء المضغ. When we chew food, these natural tooth convexities divert food away from the thin free gingiva and gingiva sulcus surroundingthe cervix of the tooth, and toward the firmer tissues of the mouth, thus minimizing trauma to the gingiva. ان أعظم انتفاخ بالسن راح يبعد جزيئات الطعام عن thin free gingiva و sulcus و هذا يقلل من ضرر اللثة. _ لازم طبيب الأسنان يراعي إرجاع height of contour سواء كومبزت أو زرع الأسنان و غيرها ..

The mid-root axis line (or root axis line) is an imaginary line through the center of the tooth root. _It is an important reference line for describing the location of tooth landmarks.

In maxillary posterior teeth The lingual cusp appear longer than the buccal cusp. In mandibular posterior teeth The lingual cusp appear shorter than the buccal cusp. ➡️ due to their alignment (lingual tilt) within the mandible.

Maxillary posterior teeth are tilted with the crowns more facial and mandibular posterior teeth are tilted with the crowns more lingual