Interceptive Class III device usage

I saw a patient the other day that was given the i-3 Interceptive Class III device to wear.  The parent wanted to know if I knew about the device and asked me if it was worth them getting another one because the first one he “chewed up” the first week.  She said it cost them almost $ 400.00 and they will have to pay another $400.00 to replace it.  The device was given by his dentist (not an orthodontist) to prevent “unwanted lower jaw growth.”  The child is 6 years old (7 in May) and presents with edge to edge occlusion, open mouth rest posture and history of upper respiratory infections, ear infections, tonsillitis, strep x2, seasonal allergies and what appears to be possible dairy sensitivities that he has been struggling with since he was an infant. I recommended an orthodontia consult first before going ahead to order the next i-3.  Have you heard of this device?  If so, what are your thoughts?  Thanks.

Answer Provided by Dr. Robert M. Mason, DMD, PhD, CCC/SLP I thank Sandra for forwarding your email to me for a reply. Some therapists had been inappropriately ordering and fitting such appliances. This interceptive appliance is certainly not appropriate for the patient you mention due to the unresolved airway/allergy issues involved. The ability of this patient to breathe adequately while wearing the appliance would certainly be questionable, and one that could lead to larger problems such as the development of a cardiac condition that could result from the inability to breathe intranasally with the appliance in place. For the patient you report on, I suspect that his destruction of the appliance is related to breathing problems he experienced during the time the appliance was in his mouth. There is a general rule in orthodontics that if the mandible is going to overgrow, it is better to let it run its course and then deal with whatever jaw relationship has occurred as a function of growth. This general rule expresses the humble view (the result of much research verification) that Man is not smarter than Nature, nor can Nature be easily manipulated by Man. The variety of functional appliances, including the well-known Frankel functional appliance used for several decades, have not been shown to stop growth of the mandible. The best that can be said of any appliance for a developing Class III condition is that they may be able to remodel the angle of the mandible; however, such remodeling is not usually maintained as a long-term positive effect. Chin caps, for example, used primarily by the Japanese to try to stop excessive mandibular growth, have a questionable history of manipulating growth, especially Class III mandibles, and are rarely used in our country except as part of a total treatment protocol where additional monitoring or stimulation is thought to be needed. There may be a place for the i-3 interceptive appliance and other interceptive-types of appliances in selected cases where habit patterns involve a mouth open, protruded tongue posture. If wearing an appliance can retract the tongue and close down an open jaw, growth can then proceed in a more normal manner. But this is different than manipulating or stopping growth. Instead, an environment is being created in which normal processes of jaw growth can proceed — much like the primary goal of orofacial myofunctional therapy. Patients who would be good candidates for such appliances should be carefully evaluated since, as mentioned above, appliance wear for patients with any airway issues could create more problems than would be resolved. I would rather send a patient for orofacial myofunctional therapy than consider appliance treatment for young children with developing malocclusions. The benefits of specific drills, self monitoring and supervised instruction by orofacial myologists provide a treatment protocol far superior to appliance wear, in my opinion.  As you know, a developing Class III malocclusion should be monitored by an orthodontist rather than being addressed by general dentists that presume to offer orthodontic services. You were quite right in recommending that the patient should be seen by an orthodontist before the family spends an additional $400 on another appliance. I will be surprised if an orthodontist recommends another appliance with the history of unresolved airway issues. It is obvious that the dentist involved did not properly evaluate the child, and your report of findings are key to not recommending such an appliance for this child.  In summary, I agree with your view that the airway issues of this child should be addressed. It is likely that the adaptations in jaw carriage and tongue posture, because of airway interferences, could be contributing to the developing Class III condition. I hope these comments have helped. Nice job of evaluating and reporting on this child!