The Orthodontics Professors
the latest in contemporary & evidence-based orthodontics
By TATE H. JACKSON
Is it not uncommon to have a patient ask if they will be able to eat and chew with bite raisers (temporary bonding material on the occlusal surface of posterior teeth). A recent study from a group in Thailand has tried to address that question by using both objective and subjective methods.
30 healthy adult dental students (age 18-25, 19 females) without any orthodontic appliances were participants in the study. All had a Class I occlusal relationships with positive overjet, and an overbite of <3mm. None had missing teeth, TM Joint dysfunction, or orthodontic treatment within the previous three years. None had third molars, but all had a full complement of permanent teeth without edentulous areas otherwise.
For all participants, chewing ability was measured both objectively and subjectively at two different time points. The objective measure (Masticatory Performance Index, MPI) was calculated as the percentage by weight of standardized food that passed through a standardized sieve after a pre-determined number of chewing strokes. The subjective measure was a validated questionnaire (Food Intake Ability, FIA).
At baseline, the objective MPI and subjective FIA were both recorded. Then, one week later, participants had Band-Lok placed on the palatal cusps of the maxillary first molars using a template to create bite-raisers that were 2mm in height. With the bite-raisers in place, chewing ability was again measured using the MPI method and FIA questionnaire.
With 2mm bite-raisers in place, the objective ability to chew decreased by an average of 43.3% (P<0.001), while the perceived ability to chew decreased by just 14.6% (P<0.001). Overbite went from an average of 2.35mm before bite-opening to -0.57mm with Band-Lok in place.
There were no differences in objective or subjective measures between male and female participants, nor was there any correlation between changes in subjective and objective measures over time across participants.
WHAT THE PROFESSOR THINKS
It is the combination of objective and subjective measures of chewing ability using a common clinical technique (Band-Lok on first molars) that gives this study clinical relevance, despite the fact that it was performed under non-clinical conditions.
Using dental students with a Class I occlusion controlled for the potential effect of various malocclusions on the ability to chew. The longitudinal design of the study was a strength, as it further helped to control for individual variation in chewing. The use of validated measures was also appropriate.
It is key to note, however that these data reflect the ability to chew immediately after bonding bite-raisers. Neither the potential effect of functional adaptation over time nor the effect of changing occlusal relationships during in active treatment were considered.
So how then might clinicians use these data in practice?
When bonding bite-raisers on molars, orthodontist can use these data to better communicate with patients using the following three points:
THE BOTTOM LINE: We expect patients to adapt to tremendous intraoral changes during orthodontic treatment. When it comes to the ability to chew, these data suggest that even if patients can adapt over time, we should be mindful of the challenges that bite-raisers might pose in the short-term.
Article Reviewed: Chidsanu Changsiripuna and Darin Pativetpinyo. Masticatory function after bite-raising with light-cured orthodontic band cement in healthy adults. Angle Orthodontist. Online. 2019.
Tate H. Jackson, DDS, MS