As part of an interdisciplinary team the discussion of overjet is an important one. Do we have too much or not enough?  Both scenarios offer their own set of challenges and orthodontics can help the restorative dentist to create the optimal function for their patients.

overjet

 

Class II canine position can leave too much overjet

As part of an interdisciplinary team the discussion of overjet is an important one. Do we have too much or not enough?  Both scenarios offer their own set of challenges and orthodontics can help the restorative dentist to create the optimal function for their patients.

The loss of overjet is a common consequence in a worn dentition case. As anterior teeth wear the eruption pathway includes a lingual component.  As tooth wear progresses the mesial -distal width of the incisors is reduced with the widest portion of the tooth worn away. The teeth tip back reducing the overjet.  This leads the patient to more wear and a repeat of the same process until upper and lower incisor can be in jeopardy. 

As we have learned it is essential to plan the position of the upper incisors for the ideal esthetics. The full smile and the lips at rest guide us to the correct position of the incisal edge and then we can rebuild the upper teeth back to more optimal size and shape. Intrusion of the worn upper incisors not only gives us the vertical space to create our optimal length, it gives us the space for the proper width proportion. In our planning it is important to realize intrusion also gives us more overjet.

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Spaces between the incisors to gain overjet

What can we do if the proper upper incisor set up produces too much overjet?  A Class II pattern at the canines can be nicely managed for lateral canine guidance. It can pose a challenge to the anterior guidance when overjet is too much. I have been challenged by Class II malocclusions from the dawn of my orthodontic training.

Let’s look at the options the orthodontist has to help you resolve the excess overjet issue. Extraction therapy in the upper arch or upper and lower arches is foundational in orthodontic training. In the right case it can be the correct plan and provide your patient with the exact occlusal foundation for the desired restoration of their smile. While we can achieve an optimal final anterior guidance solution,

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Pre treatment with crowding

it can be a less desirable solution for facial and smile esthetics. With adult patients I do find that extractions AND braces make the orthodontic treatment decision even more difficult to agreed to. 

Surgical correction of the excess overjet is an option and an important choice if the patient is concerned with a recessive lower jaw/chin profile.  In those cases it is an amazing correction for the patient and a gift to the restorative dentist to have ideal relationships to restore.

In wear cases the lower incisors wear and erupt variably along with the upper incisors. When they are intruded we again are faced with added overjet development. A diagnostic set up is a great exercise to realize how much overjet you will gain with the intrusion of worn incisors. The lowly lower incisor can help to reduce the excess overjet. Sometimes an afterthought since they have less impact on the smile esthet

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Post treatment with spacing for restoration

ics, the lower incisors can be an excellent workhorse for us in the overjet department. As lower incisors are worn and they extrude they can become significantly narrower than an unworn incisor.  As they narrow they will collapse to the lingual. In your diagnostic set up re size the incisors as you intrude them to regain some of your needed arch length.  When you procline and space the lower incisors apart you can recapture several millimeters to help establish your anterior contacts.  

The images within this article show the combination of intrusion and Class II canine left us with too much overjet to achieve anterior contacts. By building in the proclination and spacing of the lower incisors the restorative dentist can now restore with the desired anterior stops.

Donna J. Stenberg D.D.S., M.S., P.A. Spear Visiting Faculty and Contributing Author. www.stenbergorthodontics.com