THE INCISORSTHE INCISORS

THE INCISORS

There are eight of these teeth (4 in the maxilla and 4 in the mandible).

The maxillary incisors are implanted on the premaxilla. The mandibular incisors are the teeth that articulate with the maxillary incisors.

There are two incisors on each side of the midsagittal plane:

• The central incisor is closest to the middle.
• The lateral incisor is immediately distal to it.

The incisors, along with the canines, constitute the group of anterior teeth.

They have a cutting edge and their function is to cut, take or hold.

By their shape and alignment, the incisors play an important role in facial aesthetics, as they are widely exposed in chewing, speech and all facial expressions. In the articulation of certain phonemes, these teeth are indispensable

Upper central incisor

1. Timeline  : 

• Start of calcification: 3-4 months
• End of coronary calcification: 4-5 years
• Age of eruption: 7-8 years
• End of apical calcification: 10 years

3. Description :

1. Vestibular face: 
2. The crown:

• The incisor has a general trapezoidal outline below 

a stocky appearance.

• The mesial and distal sides converge in the direction 

apical

• The cervical diameter is smaller than the diameter 

    occlusal

•  the major axis of the tooth is vertical

• The free edge is straight and horizontal in 

the mesial part. It tilts distally.

•  The mesial angle is almost straight on the other hand. 

the distal angle is obtuse.

• The maximum mesial convexity is located near

 of the incisal edge. The maximum distal convexity 

     is located at the junction of the incisive 1/3 and the medial 1/3

• The mesial contour is longer and straighter 

than the distal contour.

• The vestibular face is convex, it flattens 

gradually from the middle third 

     to the incisal edge. 

• Two depressions extend from the incisal edge and 

delimit three lobes; the distal one is the largest; 

the mesial is the smallest.

• The collar is semicircular with occlusal concavity 

2. The root

• The root has a conical shape, its apex is 

generally blunt. 

• The mesial contour of the crown and root 

are aligned while on the distal side a closed angle 

distally translates a slight inclination of the axis 

radicular relative to the coronal axis 

2. Palatal face: 
3. The crown

• The palatal face is narrower than the face 

vestibular.

• The marginal ridges, mesial and distal, 

converge towards the cervical region.

• The mesial crest is straight, but the 

distal describes a sigmoid path.

• The cingulum is a regular protuberance 

slightly oblong, it can be subdivided into 

several lobes by furrows and wells.

• The lingual collar is ½ circle lower than

 the vestibular collar

2. The root:

• The root is narrower lingually.

3.3 Mesial face:

a. crown 

• It is part of a triangle with a cervical base and an incisal apex. 
• The vestibular contour is convex in the cervical third 

and the middle third. It becomes less and less convex as one approaches the incisal edge.

• The lingual contour is convex in the cervical third, concave at the level of the lingual fossa
• The incisal edge is rounded.

• The collar adopts a significant curve with concavity 

radicular and joins the vestibular and palatine necks

• The entire mesial surface is convex. It 

tends to become flat in the cervical region.

• The proximal mesial contact zone is a small

ovoid surface, close to the incisal edge.   

  b.the root:

• The root of this tooth is cone-shaped and is 

ends at the apex.

• It has a diameter roughly equivalent to the 

mesio-distal diameter.

• The root axis is in the extension of the axis 

coronary

• The apex is pointed. 

4. Distal face  : no fundamental difference is distinguished from the mesial face. Only 02 small details differentiate them: 

• The degree of concavity of the collar is less important 
• and the location of the contact point is more cervical.

3.5. Occlusal face: 

• Only the crown is visible
• The coronal outline is inscribed in a diamond.
• The vestibular contour is convex and symmetrical,
• The lingual contour is triangular.
• The mesial contour is longer, more elliptical and 

flatter than the distal.

• The incisal edge separates the two vestibular parts 

and palatine, it is straight in its mesial portion and 

its medial portion. It tilts in a lingual direction 

in its distal portion.

• The incisal edge is scalloped along its contour. 

vestibular by the depressions of the vestibular face

• The cingulum is displaced to the distal side.

THE INCISORS

  Early cavities in children need to be treated promptly.
Dental veneers cover imperfections such as stains or cracks.
Misaligned teeth can cause difficulty chewing.
Dental implants provide a stable solution to replace missing teeth.
Antiseptic mouthwashes reduce bacteria that cause bad breath.
Decayed baby teeth can affect the health of permanent teeth.
A soft-bristled toothbrush preserves enamel and gums.
 

THE INCISORS