In orthodontics, the quest for a beautiful harmonic smile often involves various intricate techniques and methods. While braces or Invisalign can make the teeth straighter, in most cases, an orthodontic specialist has many variables to consider and a complex diagnosis and treatment planning is done behind the scenes. Some of these considerations involve a patients skeletal pattern, analysis of several radiographs, the patients facial profile and balance, symmetry, as well as the macro and micro esthetics of the teeth.
This post will focus on the last point. The macro esthetics encompass the relationships of the teeth to the face, lips and gums and the micro esthetics involve the individual tooth size, shapes and shades. There are many misconceptions about interproximal reduction, many of which come from General Dentists who have the best intentions, but are ill-informed, as well as social media. It is important to remember that Orthodontists are specialists in tooth movement and what is needed to obtain the best smile and proper bite relationship.
The size and shape of the teeth play as large role in the appearance of the smile as anything that an orthodontist does with braces or Invisalign. If the teeth have irregular size or shape sometimes the teeth themselves need to be altered in order to obtain an ideal bite as well as an optimal esthetic result. Interproximal reduction, or IPR, is a technique that can be utilized in order to obtain the best orthodontic outcome.
Interproximal reduction is a simple procedure in which the size and shape of the teeth are adjusted using precise diamond embedded instruments in which minute amounts of enamel are removed. This is typically done in between the teeth where they touch one another, known as the contact point. There are several reasons why this is done:
- Tooth Size Discrepancy: The set of upper and lower teeth are like a puzzle and the individual teeth have ideal sizes in order to fit together properly. If the upper teeth are too big or the bottom teeth are too narrow in comparison, a patient will present with upper crowding, an excess overbite or spacing of the lower teeth. On the other hand, if the top teeth are too small or the lower teeth are too wide, there will be spaces on the top or crowding on the bottom. Through extensive orthodontic research, it was discovered that there are ideal proportions of the upper and lower teeth. If the upper and lower teeth do not match due to the tooth size, it is known as a "Tooth Size Discrepancy". On occasion, reduction of the upper or lower teeth is a solution.
- This is a quick, safe and pain free procedure. Tooth enamel can be as much as 2.5 millimeters thick and Interproximal reduction typically involves no more than 0.2-0.4 millimeters. After IPR, there is plenty of excess enamel to keep the teeth healthy and strong, which has be shown in countless orthodontic research. IPR does not increase the risk of cavities. Research has shown that dentists are less comfortable performing IPR routinely and orthodontists who are more likely to have researched the long term effects of IPR on the teeth are more comfortable performing the procedure. Because of this, dentists will often inform patients and their families that IPR is unsafe, will damage the teeth or other statements that are incorrect, and not backed by scientific research.
- Anatomy: Sometimes the shape of the teeth is such that an esthetic improve can be made by removing some excess enamel in order to improve the shape of the teeth or how to teeth connect to each other in order to obtain a more esthetic final result.
- Black Triangles: Sometimes due to the shape of the teeth, how they connect to each other or due to gum recession, the appearance of what are known as black triangles occur. It is noticed as triangluar "spaces" close to the gum-line. While there are not actually spaces between the teeth, if the teeth are only touching at the tips and not up to the gums, a dark triangle will apear. On occasion, IPR can reshape these teeth and reduce the size and appearance of the black triangle once the space is closed.
- Crowding: Another reason for using IPR is due to crowding of the teeth. Significant amounts of space can be created by removing very small amounts of enamel in between some of the teeth. If there is crowding between the teeth, but not enough crowding for the removal of permanent teeth, IPR can be used to create enough space for all of the teeth. In addition to create space, IPR also creates flat surfaces between the teeth which helps improve the stability of teeth to keep them straight after orthodontic treatment is completed.
- Conclusion and Considerations: IPR is a safe procedure and extensive research shows that there is no increased decay after IPR, there is improved stability of the orthodontic results after IPR due to the improved contacts, and there is no increase in sensitivity when the amount of enamel removed is within proper limits.
The author, Dr. Eric Strouse DMD MDS is a specialist in orthodontics in the practice of orthodontics in Spring Hill and Lecanto, Florida. He was trained at Muhlenberg College for his Bachelors Degree where he competed on the track and field team. He completed his dental training at the University of Connecticut School of Dental Medicine, earning a Doctorate of Medicine in Dentistry(DMD). He completed a one year General Practice Residency at St. Luke's Hospital in Allentown, PA and his specialty training in Orthodontics and Dentofacial Orthopedics at Rutgers University where he also completed a Masters in Dental Science. Dr. Strouse has been published in several Dental and Orthodontic Journals. Dr. Strouse is an expert in two-phase orthodontic treatment, phase 1 interceptive treatment, extraction and non-extraction treatment, Invisalign clear aligners, and multiple bracket systems(custom braces, self ligating braces, conventional braces). This blog is for informational purposes only.