Dental Anatomy PDF Past Paper 2024

10 Lajneh Teejan Lajneh wisdom Aseel Sharaireh  Deciduous teeth Introduction: -In Latin, decidere means to fall off or be shed (‫)تتساقط‬, like leaves from a tree. - Deciduous teeth are shed (painlessly) and replaced by permanent teeth. -In the absence of permanent rep...

10 Lajneh Teejan Lajneh wisdom Aseel Sharaireh  Deciduous teeth Introduction: -In Latin, decidere means to fall off or be shed (‫)تتساقط‬, like leaves from a tree. - Deciduous teeth are shed (painlessly) and replaced by permanent teeth. -In the absence of permanent replacements (sometimes) they can remain functional for many years. - The primary set of teeth develop during the embryonic stage of development and erupt during early childhood and last until 12 years of age -The primary teeth have been called temporary, milk, or baby teeth. These terms are improper because they foster the implication that these teeth are useful for a short period only. - the primary teeth are important for the physical development and to allow the proper growth of the oral cavity. -Premature loss of primary teeth because of dental caries is preventable and should be avoided. (so It's not something you should plan in your treatment to just get red of - extract- the primary teeth due to minor curious regions) - Called Milky teeth because of their white appearance. -The first primary tooth comes around 6 months of age and the 20th and last primary tooth erupts at around 2.5 years of age. The primary teeth are replaced beginning usually at about age 6. -notice that babies start having solid food at about 6 months and can be free eating -what adults eat- at 1 year of age ; they have many teeth so they can grind the food - the primary teeth area only is up to 6 years -at 6years of age we will have mixed stage of primary + permanent teeth (first eruption of lower molars). -If we take a picture of the skull of a child, we can see that the crowns of the permanent teeth are almost ready and they are much bigger than the primary Human dentition : What comprises the primary teeth? A. Four central incisors (two upper and two lower) B. Four lateral incisors (two upper and two lower) C. Four canines (two upper and two lower) D. Four first molars (two upper and two lower) E. Four second molars (two upper and two lower) (NO PREMOLARS , NO THIRD MOLARS ) Teeth annotation : Universal , FDI , Palmer: Palmer's /Zsigmondy (used in hospitals) FDI Universal  ‫تقسيم‬ : ‫أوضح‬ Universal FDI palmer Function of primary teeth: 1. Masticatory : (similar to the permanent) The American Academy of Pediatrics recommends children be introduced to foods other than breast milk or infant formula when they are about 6 months old (when primary teeth start to appear) primary teeth serve their primary function which is: cutting tearing and grinding of food so that small food particles are passed on to the GI track for digestion. Primary teeth start appearing as the human’s feeding demands starts changing and solid food is introduced ‫أي أن االسنان تتحفز للظهور عندما يصبح االنسان بحاجة لقيم غذائية أكثر من الحليب والطعام السائل‬ 2. Craniofacial Development : (special function for primary teeth) primary teeth are small and permanent teeth are much bigger, why is that?? As the child grows his skull, his maxilla and his mandible grow and so there is much more space which requires bigger teeth thus a permanent well accommodated dentition. So the primary teeth preserve the space for the permanent teeth at the early life by preventing the movement of the adjacent permanent tooth to occupy the space that is supposed to be left for another permanent tooth. ‫أي عندما ينمو الفك يصبح بحاجة ألسنان أكبر لتمأل الفراغ وحجم األسنان الدائمة يصبح أنسب لحجم الفك‬ (PRIMARY TEETH FIT THE JAWS OF THE CHILD, PEREMENANT TEETH FIT AN ADULT) 3. speech and appearance to say words correctly without any resonant sounds, also the beauty of the teeth effects the mental well-being of the person 4. Space maintenance and permanent teeth guidance (special function for primary teeth( Tooth follicle releases chemicals (cellular signaling), and the chemical signals to the roots of the primary teeth where natural physiological resorption starts happening that guides the crowns of the permanent teeth toward where it should be coming out. (Primary teeth guide the permanent successors) General differences between deciduous and permanent teeth: PRIMARY TEETH PERMANENT TEETH Smaller in size Larger in size Greater crown width/height ratio Lesser crown width/height ratio Relatively flat occlusal table Occlusal table is well contoured and present different curves Smaller crown height/tooth Larger crown height/tooth length ratio length ratio Notice that: The primary tooth is Small , Short , Fat , Flat CROWNS COMPARISON: PRIMARY TEETH PERMANENT TEETH Whiter in color/ thinner dentine Less white and more yellowish in color/ thicker underlying dentine No mamelons Mamelons highly present when teeth first erupt Cusps are slender (skinny) and tend to Cusps are less conical be more conical ,with More bulging B& L cervical ridges, and a Constricted cervix More supplemental grooves Less supplemental grooves ROOT COMPARISON: PRIMARY TEETH PERMANENT TEETH Shape: highly divergent roots and Shape: Larger, thicker and more bulbous slender Root Truck: Small Root trunk: Large Width: Narrow mesiodistally Width: Broad mesiodisally Physiological resorption: During Physiological resorption: Absent shedding of teeth (guidance) PULP COMPARISON (anatomical features of the pulp) PRIMARY TEETH PERMANENT TEETH Pulp chamber: Larger Pulp chamber: Smaller Accessory canals: more present in the Accessory canals: more present in the furcation area apical portion of the root Pulp Horns: more prominent and close Pulp horns: flattened and not close to to the outer surface the outer surface Anatomy and morphology : Central incisor: Lateral incisor: Canine: First molar: Second molar:  Chronology: Guess the age ??)-⁠⁠: Central and lateral incisors are erupted (notice the mamelons) so this child's age is between 8 and 9 years Clinical implications : -Primary teeth are much thinner so cavity preparation must be cautiously (carefully) carried out so that pulp exposure does not mistakenly occur. (pulp exposure can happen easily because the pulp horns are more prominent and close to the outer surface) ‫حيث أن اللب ينكشف بسهولة بسبب كبر حجمه و قربه من‬, ‫يجب الحذر عند حفر االسنان اللبنية حتى ال ينكشف اللب‬ ‫سطح السن‬ - Root canal treatment is different to enable the natural physiological resorption to occur. (Primary teeth have a complex pulp system and you have to follow a different RCT protocol than the permanent teeth to enable the natural physiological resorption even after you do the RCT). ‫ حيث يجب الحذر في التعامل معه‬, ‫( معاملة الجذر في السن اللبني تختلف عن معاملة الجذر في السن الدائم‬natural physiological resorption) follicles ‫حتى يستمر في امتصاص المواد الكيميائية المفرزة من ال‬ -During root extraction the thin divergent teeth can be broken easily. -After extraction, space maintenance must be planned ahead of procedure to preserve the space for the permanent teeth. (craniofacial development function) ‫عند قلع االسنان اللبنية يجب صيانة مكان السن حتى يكون جاهزا لالسنان الدائمة‬ -Behavioral management! classII primary mandibular second molar https://youtu.be/X6yJGZ8OyWg ‫ومن يتهيب صعود الجبال يعش أ َبــدَ الدهــر بيــن الحــفر‬ End sheet 10