The 2nd Permanent Molars in Orthodontics: To Bond or Not to Bond?

by Shadi Samawi

Don’t Forget the Second Molars
“There is no excuse for failing to address the second molars in our treatment planning, especially considering the wealth of information available to the practicing orthodontist today. It is up to us to apply the therapeutic concepts that have already been developed for dealing with these challenging teeth, so that we can achieve the best possible long-term results for our patients.”

Back to Clinical Orthodontics, I would like to talk about the issue of including the second molars in fixed appliance treatment. The case for habitual bonding of the second permanent molars in orthodontic treatment with fixed appliances has been made on many occasions in orthodontic literature. however, it seems that -to date- many of us still overlook this vital step and do not perform it on a regular and consistent basis, thus loosing the potential benefits of such a measure. I, for one, have been guilty of this on many occasions in the past. The reasons for this way of thinking are many; some subscribe to the notion that including the 2nd molars in the appliance might lead to an unwanted decrease in overbite especially in anterior open bite and high-angle cases, due to their posterior extrusive effect; the so-called “wedge” effect. others consider bonding the 2nd molars as only extra work due to their position in the oral cavity; often difficult access and difficult isolation. The difficulties are numerous when attempting to band the 2nd molars, but direct bonding also can lead to bond failure more often than not, due to the difficult moisture control in many cases.  Many practitioners will bond 2nd molars only if deemed necessary when there is a gross malalignment or rotation affecting the 2nd molar in relation to the 1st molars – often not from the start –  and will not bond them otherwise. However, with a higher percentage of adult patients seeking orthodontics, we often encounter issues such as inappropriate buccolingual alignment, mesiodistal tip and axial alignment, incorrect root torque, and marginal ridge discrepancies with the adjacent first molars. All these issues necessitate correction in order to be able to achieve optimal results.

In the ( MBT) philosophy, for example, It is recommended to always bond the 2nd molars slightly more to the occlusal to avoid extrusion and adversely affecting the overbite. This is certainly something I’ve been personally doing for a long time, with excellent results and minimal adverse effects on overall occlusion even in high angle cases. When using self-ligated bracket systems, bonding the 2nd molars is considered mandatory – as in the Damon System philosophy. The short article by Dr. Robert G. Keim (VOLUME 41 : NUMBER 05 : PAGES (243-244) 2007) published in The Editor’s Corner in the Journal of Clinical Orthodontics (JCO) in 2007 is well worth a read.

What is your opinion and experience in relation to this topic? Do you regularly include the 2nd permanent molars with fixed appliance treatment? I would love to read your thoughts in the comments.