The posterior teeth does not make contact (open bite). This can be caused by the investing technique. In class 1 the goal is to get central occlusion which means the lingual cusps of the maxillary teeth should occlude in the central fossae of the mandibular teeth. -The cusps of the maxillary canine occlude between the mandibular canine and 1st premolar. -Maxillary 1st premolar must occlude between the mandibular 1st premolar and 2nd premolar. -Maxillary 2nd premolar occludes between the mandibular 2nd premolar and 1st molar. - Maxillary bucal-mesial cusp of the 1st molar should occlude between the mandibular buccal-mesial cusp and buccal-distal cusp of the 1st molar. -Maxillary 2nd molar buccal-mesial cusp in between the mandibular 2nd molar buccal mesial cusp and buccal-distal cusp. -Maxillary 1st pre molar can be tilted slightly so that the root is a bit more distally -Mandibular 2nd pre molar can also be tilted slightly distally and the gingiva can be more open to reveal more of the tooth.
A common factor to all branches in dentistry is occlusion and it is a term to describe the contact relationship of the upper and lower teeth. Resultant forces are created whenever the opposing teeth come into contact with each other. These forces may vary in magnitude and direction but it must always be resisted by supporting tissues. Teeth, whether natural or artificial, are not immobile; therefore occlusion can never be considered a purely static relationship. Natural teeth move in their sockets, they move under load into their sockets and return to their position when the load is removed. Artificial occlusion discloses more apparent movement since the teeth move as a group on a common base. Because of the nature of the supporting structures. Because these structures changes all the time, artificial occlusion must make accommodation for this.
Looking at the example of posterior occlusion, there can be many reasons why it is occluding in this fashion. It appears hat the 1st and 2nd molars of the maxilla are tilted more outwards towards the buccal regions. This could be the result of the initial set up or the wax being too soft at the time allowing the teeth to shift or the curve of Spee has not been maintained. It could also be the positioning of the 1st and 2nd molars of the mandible is shifted more towards the lingual aspects. The reason for this can be the placement of teeth during initial set up. Over packing can also displace the teeth as to much downward pressure is applied resulting in the teeth being dislodged from their original position. Resultant forces are not evenly spread onto the occlusal table but more on the cusp tips of the maxillary molars. Intercuspation is not possible as the two occlusal surfaces are not in harmony but that only the cusps of the maxillary molars are aligned in the fossae of the molars of the mandible. This will in turn compromise the stability of these denture bases, traumatize the oral supporting structures, and accelerate bone re-sorption.
You have to comment on what you see and the corrections that needs to be done, if any. So if you see that the posterior teeth are not occlusion correctly you comment on that and how you think it needs to be fixed.
According to the ‘posterior occlusion picture’, it clearly indicates the following visible errors: 1. Curve of Spee not presented. 2. No maximum intercuspations relationship, (result no curve on Monson). To prevent these errors: Before processing the denture use the BULL rule. Must adjust the buccal upper cusps and the lingual lower cusps to ensure that there is balancing side contacts between upper palatal and lower buccal cusps (maximum intercuspations) while maintaining the curve of Spee. Curve of Monson will form naturally.
It seems that only the palatal cusps of the first molar and second maxillary molars are making contacting with the central fossae of the lower posterior teeth from this angle. The working cusps in class I occlusion are the palatal cusps of the upper teeth and the facial cusps of the lower teeth, and they should ideally make contact all along their opposing fossae. If the cusps have a steep inclination, a sufficient compensating curve must be formed to allow for maximum intercuspation and masticatory function. The curve viewable in the picture does not seem to be adequate.
If the picture is of a denture post processing, the errors might be due to excessive pressure whilst compression packing the denture or heating up the wax to much whilst waxing up. It could possibly be corrected by doing selective grinding in the manner mentioned by Joe.
Posterocclusion is the most effective contact of the molar and bicuspid teeth of both the maxilla and mandible that allows for all the natural movements of the mandible essential to normal mastication and closure. Geometrical form of occlusal surfaces, spatial arrangement of teeth in dental arches and condition of supporting structures has crucial influence on masticatory function efficiency. Furthermore, proper geometry of occlusal surfaces of posterior teeth determines appropriate distribution of occlusal load to the supporting structures and normal activity of the masticatory muscles and temporomandibular joints. Most of previously performed studies were directed to the relation between form of occlusal surfaces and chewing efficiency as well as temporomandibular joint pathology, whereas the influence of geometrical form of occlusal surfaces in guiding teeth on forces distribution in constituent parts of masticatory system can be further investigated. In the example given, posterior anatomic tooth forms with a 33 degree articulation had been used which provide tight interdigitation in an Angle class I occlusion.
In Angle class I occlusion;
1. The mesiobuccal cusp of the maxillary first molar and the buccal groove of the mandibular first molar are in relation - if this molar relationship exists, then the teeth can align into normal occlusion. 2. The mesial incline of the upper canine occludes with the distal incline of the mandibular canine. 3. The distal incline of the maxillary canine occludes with the mesial incline of the mandibular first premolar.
In the example given, these relationships do not exist entirely. Occlusal load will not be equally distributed due to premature contact areas that exist on the mesial and distal inclines of the maxillary and mandibular posterior teeth. Selective grinding may be avoided if the long axes of the maxillary posterior teeth are inclined distally and the necks inclined buccal to the saggital plane.
You have to comment on what you see and the corrections that needs to be done, if any. So if you see that the posterior teeth are not occlusion correctly you comment on that and how you think it needs to be fixed.
In any set-up occlusion is very important. From what am observing, the whole of the posterior teeth are not occluding properly. The mesial cusp of the maxillary 1st molar is a bit anteriorly allowing the whole posterior teeth to move forward and not occlude properly. If you take a look at the 2nd premolar it is a bit anterior to where is suppose to occlude on the mandibular posteriors. As being taught in the first year class that when you first occlude the two first molars of both jaws correctly then the whole set up will eventually come right in terms of occlusion and balancing of the denture will be accurate.
An important factor in denture construction is occlusion. No occlusion present at the posterior teeth because of the posterior teeth not making contact (open bite). An open bite can be prevented during the packing stage of processing a denture. The denture should be kept in the pneumatic press long enough until that pressure is maintained in the flasks. The maxillary first premolar is leaning to the mesial aspect while it should be angled like the second premolar. The first premolar should be pushed distal until it is up straight. The maxillary canine is angled up straight. The neck of that canine should be pushed slightly distally in order for the canine to lean slightly distally.
The posterior teeth does not make contact (open bite). This can be caused by the investing technique. In class 1 the goal is to get central occlusion which means the lingual cusps of the maxillary teeth should occlude in the central fossae of the mandibular teeth.
ReplyDelete-The cusps of the maxillary canine occlude between the mandibular canine and 1st premolar.
-Maxillary 1st premolar must occlude between the mandibular 1st premolar and 2nd premolar.
-Maxillary 2nd premolar occludes between the mandibular 2nd premolar and 1st molar.
- Maxillary bucal-mesial cusp of the 1st molar should occlude between the mandibular buccal-mesial cusp and buccal-distal cusp of the 1st molar.
-Maxillary 2nd molar buccal-mesial cusp in between the mandibular 2nd molar buccal mesial cusp and buccal-distal cusp.
-Maxillary 1st pre molar can be tilted slightly so that the root is a bit more distally
-Mandibular 2nd pre molar can also be tilted slightly distally and the gingiva can be more open to reveal more of the tooth.
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ReplyDeleteA common factor to all branches in dentistry is occlusion and it is a term to describe the contact relationship of the upper and lower teeth.
ReplyDeleteResultant forces are created whenever the opposing teeth come into contact with each other. These forces may vary in magnitude and direction but it must always be resisted by supporting tissues.
Teeth, whether natural or artificial, are not immobile; therefore occlusion can never be considered a purely static relationship.
Natural teeth move in their sockets, they move under load into their sockets and return to their position when the load is removed. Artificial occlusion discloses more apparent movement since the teeth move as a group on a common base. Because of the nature of the supporting structures. Because these structures changes all the time, artificial occlusion must make accommodation for this.
Looking at the example of posterior occlusion, there can be many reasons why it is occluding in this fashion.
It appears hat the 1st and 2nd molars of the maxilla are tilted more outwards towards the buccal regions. This could be the result of the initial set up or the wax being too soft at the time allowing the teeth to shift or the curve of Spee has not been maintained. It could also be the positioning of the 1st and 2nd molars of the mandible is shifted more towards the lingual aspects. The reason for this can be the placement of teeth during initial set up. Over packing can also displace the teeth as to much downward pressure is applied resulting in the teeth being dislodged from their original position.
Resultant forces are not evenly spread onto the occlusal table but more on the cusp tips of the maxillary molars. Intercuspation is not possible as the two occlusal surfaces are not in harmony but that only the cusps of the maxillary molars are aligned in the fossae of the molars of the mandible. This will in turn compromise the stability of these denture bases, traumatize the oral supporting structures, and accelerate bone re-sorption.
You have to comment on what you see and the corrections that needs to be done, if any. So if you see that the posterior teeth are not occlusion correctly you comment on that and how you think it needs to be fixed.
DeleteAccording to the ‘posterior occlusion picture’, it clearly indicates the following visible errors:
ReplyDelete1. Curve of Spee not presented.
2. No maximum intercuspations relationship, (result no curve on Monson).
To prevent these errors: Before processing the denture use the BULL rule. Must adjust the buccal upper cusps and the lingual lower cusps to ensure that there is balancing side contacts between upper palatal and lower buccal cusps (maximum intercuspations) while maintaining the curve of Spee. Curve of Monson will form naturally.
It seems that only the palatal cusps of the first molar and second maxillary molars are making contacting with the central fossae of the lower posterior teeth from this angle. The working cusps in class I occlusion are the palatal cusps of the upper teeth and the facial cusps of the lower teeth, and they should ideally make contact all along their opposing fossae. If the cusps have a steep inclination, a sufficient compensating curve must be formed to allow for maximum intercuspation and masticatory function. The curve viewable in the picture does not seem to be adequate.
ReplyDeleteIf the picture is of a denture post processing, the errors might be due to excessive pressure whilst compression packing the denture or heating up the wax to much whilst waxing up. It could possibly be corrected by doing selective grinding in the manner mentioned by Joe.
Posterocclusion is the most effective contact of the molar and bicuspid teeth of both the maxilla and mandible that allows for all the natural movements of the mandible essential to normal mastication and closure. Geometrical form of occlusal surfaces, spatial arrangement of teeth in dental arches and condition of supporting structures has crucial influence on masticatory function efficiency. Furthermore, proper geometry of occlusal surfaces of posterior teeth determines appropriate distribution of occlusal load to the supporting structures and normal activity of the masticatory muscles and temporomandibular joints. Most of previously performed studies were directed to the relation between form of occlusal surfaces and chewing efficiency as well as temporomandibular joint pathology, whereas the influence of geometrical form of occlusal surfaces in guiding teeth on forces distribution in constituent parts of masticatory system can be further investigated. In the example given, posterior anatomic tooth forms with a 33 degree articulation had been used which provide tight interdigitation in an Angle class I occlusion.
ReplyDeleteIn Angle class I occlusion;
1. The mesiobuccal cusp of the maxillary first molar and the buccal groove of the mandibular first molar are in relation - if this molar relationship exists, then the teeth can align into normal occlusion.
2. The mesial incline of the upper canine occludes with the distal incline of the mandibular canine.
3. The distal incline of the maxillary canine occludes with the mesial incline of the mandibular first premolar.
In the example given, these relationships do not exist entirely. Occlusal load will not be equally distributed due to premature contact areas that exist on the mesial and distal inclines of the maxillary and mandibular posterior teeth. Selective grinding may be avoided if the long axes of the maxillary posterior teeth are inclined distally and the necks inclined buccal to the saggital plane.
You have to comment on what you see and the corrections that needs to be done, if any. So if you see that the posterior teeth are not occlusion correctly you comment on that and how you think it needs to be fixed.
ReplyDeleteIn any set-up occlusion is very important. From what am observing, the whole of the posterior teeth are not occluding properly. The mesial cusp of the maxillary 1st molar is a bit anteriorly allowing the whole posterior teeth to move forward and not occlude properly. If you take a look at the 2nd premolar it is a bit anterior to where is suppose to occlude on the mandibular posteriors. As being taught in the first year class that when you first occlude the two first molars of both jaws correctly then the whole set up will eventually come right in terms of occlusion and balancing of the denture
ReplyDeletewill be accurate.
An important factor in denture construction is occlusion. No occlusion present at the posterior teeth because of the posterior teeth not making contact (open bite). An open bite can be prevented during the packing stage of processing a denture. The denture should be kept in the pneumatic press long enough until that pressure is maintained in the flasks. The maxillary first premolar is leaning to the mesial aspect while it should be angled like the second premolar. The first premolar should be pushed distal until it is up straight. The maxillary canine is angled up straight. The neck of that canine should be pushed slightly distally in order for the canine to lean slightly distally.
ReplyDelete