Maxillary Premolars Flashcards
Describe the Maxillary First Premolar cervical line
Cervical line is “flatter”. General trend is flatter cervical line as you move posterior
Are the Maxillary First Premolars greater mesiodistally or faciolingually?
Faciolingually greater than Mesiodistally
Decribe the Maxillary First Premolars from the buccal view
Trapezoidal. The cusp tip is relatively pointed and will be slightly distal to the mesiodistal long axis bisector (This is the only permanent tooth where the mesial cuspal ridge of the facial cusp is longer than the distal cuspal ridge). Prominent Facial ridge bordered by noticeable developmental depressions.
Where do the Maxillary First Premolars contact?
Mesial Proximal Contact is slightly more cervical than Distal Proximal Contact. However both contacts are still located in the middle third
Where is the concavity on the Maxillary First Premolars?
Mesial outline of the crown between the medial contact area and the cervical line is slightly concave. This is primarily due to the developmental root depression on the mesial surface that extends over the CEJ onto the occlusal surface
Describe the root of the Maxillary First Premolars
The root of this tooth is usually bifurcated into a facial and a lingual root. Since the facial root is usually wider than the lingual root, the lingual root will not always be visible from the facial aspect, but may be if the root apices curve in opposite directions
Compare the lingual and buccal cusp from the lingual view
Lingual cusp more narrow and shorter than buccal cusp (at least 1 mm shorter). The lingual cusp is slightly mesial to the mesiodistal long axis bisector; therefore, the mesial cusp ridge will be shorter than the distal cusp ridge. It is a characteristic of the lingual cusps of both max premolars to “swing” or “point” to the mesial. (This is a very significant in distinguishing between the 1st and 2nd maxillary premolars.
Describe the Maxillary First Premolar from the mesial view
Trapezoid. Cusp tips are located within the confines of root trunk. The height of contour is not at the cusp tip. Buccal height of contour is located in the cervical 1//3, the lingual height is located in middle 1/3. Triangular ridges on maxillary premolars tend to be approximately the same length. Their slope toward the central groove is said to be steeper than for any other tooth.
Describe the mesial marginal ridge and developmental groove of the maxillary first premolar.
The mesial marginal ridge is almost perpendicular to the faciolingual long axis bisector. The Mesial Marginal Developmental Groove crosses the ridge and extends into the Mesial Developmental Depression
Describe the point of contact from the mesial view of the maxillary first premolar.
The mesial proximal contact is facial to the Mesial Marginal Developmental Groove.
Describe the root of the maxillary first premolar from the mesial view
The root trunk length will vary, but the apical 1/4 of the root system will usually have a facial and a lingual root. Relatively deep developmental depression regardless of the number of roots. (The mesial developmental depression of the crown is a continuation of the mesial developmental depression of the root extending onto the crown surface)
Describe the distal marginal ridge and developmental groove of the maxillary first premolar.
The distal marginal ridge is more cervically positioned than the MMR and is uninterrupted (there is no groove crossing the ridge).
Describe the point of contact from the distal view of the maxillary first premolar.
The distal proximal contact is also facial to the faciolingual long axis bisector, but is located more occlusal than the mesial contact, and is wider faciolingually since it contacts a wider tooth. Crown surface cervical to the contact area is smoothly convex. No distal depression.
Describe the root of the maxillary first premolar from the distal view
A distal root depression is present but not nearly as prominent as the mesial.
Compare the faciolingual and mesiodistal dimensions from the occlusal view of the maxillary first premolars
Faciolingual dimension is much greater than the Mesiodistal dimension.
