Pretend you are a teacher preparing a quiz for the text I will provide. 
            Each quiz question should follow the format below. 
            Ensure that you carefully recheck the questions and answers for accuracy. 
            The output should be a ready-to-use list of dictionaries for the Python eval function:

            [

                    "question": "WRITE THE QUESTION HERE",
                    "options": ["A) OPTION_1", "B) OPTION_2", "C) OPTION_3", "D) OPTION_4"],
                    "answer": INDEX_OF_CORRECT_ANSWER_IN_OPTIONS_LIST,
                    "explanation": "EXPLAIN WHY THE ANSWER IS CORRECT"

            ]

            Text:
            ation is a characteristic feature of lower teeth    
This lingual inclination facilitates proper occlusion 
 
 
 
 
40 
 
Mandibular central incisor 
-Is the first mandibular tooth from the midline. 
-Its crown has fan shaped appearance. 
-It is the most symmetrical tooth in the permanent dentition.  
 -It is the smallest tooth in the permanent dentition. 
- The length of the root is as great, if not greater, than that of the upper central incisor. 
Chronology: 
 Enamel organ appearance: 5 m.i.u. 
 Beginning of calcification: 3-4 m.  
 Crown completed: 4-5y. 
 Eruption: 6-7y. 
 Root completed:9 y. 
 
                                      Various views of a permanent mandibular right central incisor.                                                              
Facial outlines 
1-Labial outline and surface anatomy:  
The crown: 
The geometric outline of the crown is trapezoid with the smallest of the uneven side 
cervically. 
41 
 
The mesial and distal outlines of the crown are straight from the incisal angles to the 
contact areas (in the incisal third). Then, they taper evenly from the contact areas 
to the (neck), giving the crown far shaped appearance. 
Contact areas: both are incisal to the junction of the incisal and middle thirds of the crown. 
 Mesial It is found in the incisal third near the mesioincisal angle almost with the 
incisal edge. 
 Distal It is found in the incisal third, nearly at the same level as the mesial contact 
area. 
 Incisal outline: the incisal ridge is straight and is at nearly a right 
angle to the long axis of the tooth. 
 Mamelons are usually present on newly erupted teeth. 
The mesio and distoincisal angles are relatively sharp.  
Cervical line: is evenly convex toward the root.  
Surface anatomy: 
 Elevation 
The labial surface of the crown tends to be convex, particularly in the cervical third, 
and flattens out toward the incisive third.  
 Depression 
The labial surface shows few traces of developmental lines, which are more, 
demarcated in newly erupted teeth. 
Outlines and surface anatomy of the root: 
-The tooth has only one root. 
-The labial surface of the root is narrow and convex. 
-The mesial and distal outlines are straight till the apical portion. 
-The apical third (in most cases) ends in a small pointed apex, which tends to curve 
distally.  
-The root appears longer as compared to the crown length. 
 
 
 
42 
 
2-Lingual outlines and surface anatomy:  
The crown: 
-The crown is narrower lingually than labially due to lingual convergency. 
-The outline of the crown is much more symmetrical than any incisor (even the lower 
lateral incisor). 
-The lingual surface is smooth. 
The cervical line: is convex toward the root. 
Surface anatomy:  
 Elevations:  -The marginal ridges and cingulum are less well developed. 
 - The incisal ridge is narrow and rounded or flat. 
 Depressions:  
 -The lingual fossa: the lingual surface shows a shallow concavity in the middle and 
incisal thirds. 
Th

            Quiz: