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Class II division 2

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Here is a Class II division 2 case. We observe a backward shift of the lower dentition (red arrows). On the right, we observe a posterior crossbite of the first molars (green circle). The disposition of the 4 upper incisors is typical and pathognomonic of a Class II division 2. In addition, the upper left canine is not only impacted, but also transposed between the central and lateral incisors (blue circle). Normally, the canine is located between the lateral incisor and the first premolar.

Class II division 2

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Impaction and transposition of the upper left canine (blue circle)

The panogram shows well the transposition of the canine (blue circle) between the central and lateral incisors. Note that the root of the primary canine shows no resorption compared to the right primary canine where we only see the crown and the root of the primary tooth is no longer present.

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Sequence of treatment

• Maxilla:

Rapid palatal expansion and distalization of the first molars (backward movement)

Surgical ligature of the impacted canine

• Bonding of SPEED™ brackets

• Alignment of the maxillary dental arch

Traction of the canine

Correction of the transposition

• Alignment of the left lateral incisor

• Finishing

• Removal of fixed appliances (brackets)

• Retention

• Mandible:

• Bonding of SPEED™ brackets

• Alignment and preparation on right arch

• Correction of the sagittal (anteroposterior) relationship with intermaxillary elastics

• Finishing

• Removal of fixed appliances (brackets)

• Retention

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Evolution of orthodontic treatment

Evolution after 18 months of treatment

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Expansion appliance on panoramic X-ray

After 18 months of treatment, the relationship in width of the upper maxilla with the mandible became normal because of the palatal expansion. The sagittal (front-back) relationship is normal (fit of red arrows on the image on the left) because the posterior teeth moved back during the palatal expansion with a Pendulum appliance.

On the X-ray, we can identify the expansion screw, the supports bonded to the premolars, the springs which moved back the molars and the space that was created.

Intermaxillary elastics are used to maintain the sagittal correction.

The upper left canine is visible through the mucosa. It goes over the lateral incisor on which a bracket was not bonded. It is important to let the lateral incisor move freely toward the palate while the canine jumps over it. There is an important risk to cause root resorption of the lateral incisor by the pressure that the canine crown puts on the tooth while it moves above the root. Sequential X-rays were taken to monitor the situation. The traction vector of the impacted canine was lateral, that is outward first until the root of the lateral incisor was no longer in danger. Afterwards, we started the vertical movements. The cantilever armspring is made of a superelastic nickel-titanium alloy. GAC Dentsply is the supplier. The product code is Sentalloy rotating spring #10-003-01, 02, 03, 04. See another example of cantilever on the page impacted canine/mechanotherapy.

When the canine was visible in the mouth, we had to proceed with the alignment of the lateral incisor and the straightening up of the canine. There were only 2 teeth to move, but the amplitude of movement required to have each of these teeth aligned correctly was considerable. In two words, it took time.

Final result

Final occlusion 6 weeks after the brackets were removed

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Here is the result obtained at the end of the orthodontic treatment which will have lasted 3 years. The determining factor in the duration of treatment was the correction of the canine-lateral incisor transposition. This added up to the other problems already enumerated:

• Problem with the width of the palate (crossbite).

• Backward shift problem of the lower dentition (mandibular retrognathia).

• Problem with an impacted canine.

Remodeling of the gingiva on the upper canine and the lateral incisor on the left side will continue. The patient was advised to clean this area well with the toothbrush and dental floss. For that matter, you can notice a light gingival bleeding caused by bacterial plaque accumulation due to inadequate maintenance.

Final panoramic X-ray

Final panoramic X-ray of the Class II division 2 case

The panoramic X-ray shows a good root parallelism (the teeth are distributed in parallel from one another). Resorption of the root of the lateral incisor can be seen and can be explained by the perilous jumps that were done between the canine and the lateral incisor.

The septal bone between the canine and the lateral incisor seems absent. This can be explained by the proximity of the canine crown against the root of the lateral incisor during the treatment. Never having enough space during the treatment, the septal bone could not develop. We will have to re-evaluate in 6 months after the remodeling of the alveolar bone, consecutive to an orthodontic treatment, will have occurred. The fate of the third molars will have to be re-evaluated in a couple of years.

Initial and final cephalometric X-rays

Initial and final cephalograms

The impacted canine is indicated by the red arrows on the initial cephalogram.

The final cephalogram shows the completed correction and an adequate relationship between the upper and lower incisors.

The relationship between the lips and the nose-chin tangent stayed similar.

Questions and comments

Leave a comment

  1. Emanuela says:

    I have a question: i am an adult, i had a 2 class 2 division with an agenesia of lateral incisor in mandible. is good to have a bimax surgery whitout this tooth? or is better to gain the space with synfiseal distraction and put an implant and then correct the malocclusion? thanks for the replay

  2. It may not be necessary to do sympphyseal distraction to gain space to place an implant to replace the missing tooth and then have the bimaxillary surgery to correct the cl II div 2.

    I have done some mandibular distraction. It is a good technique, but not an easy one. You may see one my case if you visit my professional facebook page.

    Keep in mind that it is possible to obtain a functionnal occlusion with one missing lower incisors.

    I hope that help.

    Best regards

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