For part three of this series, I will be discussing interventional orthodontics to control habits such as thumb sucking, finger biting and a tongue thrust. As a quick refresh, parts one and two discussed interceptive orthodontic treatment for dental development or eruption anomalies and facial growth modification. In regards to habits, the earlier identified and treated, the easier it is for the patient as well as orthodontist to control. I have seen adults with a thumb sucking habit, and it is much harder to retrain, and the dentofacial side effects are significant.
Thumb sucking is a common habit starting at infancy. Why? It is comforting. However, thumb sucking often goes hand in hand with the development of a tongue thrust habit. I will be discussing a tongue thrust in its own section, so keep patient :) It is very important to address this habit before a child gets adult teeth. If a thumb sucking habit persists, it may change the upper and lower jaw growth patterns and misalign the teeth. Generally speaking, thumb sucking will cause an open bite. In addition, the pressures applied by the thumb/tongue will cause the upper front teeth to flare out, while the lower teeth can tip inwards. Additionally, the pressure will inhibit proper palatal development. If you remember from previous sections, high-vaulted palates are highly associated with mouth-breathing. I mentioned in part 2 that mouth-breathing has negative impacts on facial growth – particularly the vertical “adenoid faces” pattern. We want to avoid this! Furthermore, thumb sucking increases a child’s risk for infection and development of a callus on the thumb.
Ideally, I would recommend to try to kick the habit by four years old. Positive reinforcement is a great non-invasive measure. This means, offering comfort during “triggers” for the habit. Bitterants or placing gloves or taping the hands are other slightly more involved techniques. If none of these work, a habit breaker appliance may be fabricated. The appliance is usually called a “palatal crib”; it is cemented in
and a child cannot place their thumb in the anterior portion of their mouth any longer. Placing this appliance and ending the habit will allow for the bite to passively close, like magic! Please keep in mind though, that limited phase one orthodontics may be indicated to completely close the open bite.
Next, I’d like to discuss finger biting. The concepts are very similar to thumb sucking. Finger biting will also cause flaring of the upper teeth. Likewise, calluses may develop on the involved fingers and/or infection. I would follow the same line of recommendations as breaking the thumb sucking habit. Starting with least invasive and placing an appliance in indicated.
Lip biting, a habit I actually remember doing as a child, will often coincide with a class II malocclusion. This means the top teeth will protrude (i.e. increased overjet) and often times these children will have lip incompetence. This means the muscles around the mouth will strain to close the mouth. The overjet is often-times equal to the thickness of the lip (makes sense, right?). Similarly to the other habits, the upper teeth may flare and the lower teeth may tip inwards. You may notice that the lips may be chapped or cracked, especially in the Winter. Unfortunately, there are not any appliances that I am aware of to intervene with this habit, so positive reinforcement to break the habit may be the best bet followed by applying a bitterant on the lip.
Finally, I would like to discuss the tongue thrust habit, which is highly common in children and in adults, if left untreated. As I mentioned, a tongue thrust may occur sometimes as a result or incombition with a thumb sucking habit. Again, it is important to control the habit. I will often tell patients to retrain their tongue to keep on the roof of their mouths, if possible. Again, the earlier you intervene, the easier it is to modify this habit. Tongue spurs or the palatal crib are especially helpful, but definitely look barbaric! Most adults will not tolerate these devices well, so it is important to address ideally in childhood.
Here is a case where tongue spurs were placed and the bite naturally closed:
You can see this patient also has an open bite and dental spacing; all of these are commonly found together. The tongue is a powerful muscle, do not underestimate it! These cases, retainers are very important, sometimes with tongue spurs placed to maintain habit control. It can take over a year to break a tongue thrust habit, and possibly longer in adults.
There are certainly other habits that can cause dentofacial damage, such as biting on an object such as a pen, pencil or toothpick. It is important to address these habits as well to prevent damage to the teeth themselves as well any adverse muscular/growth changes that may result.
Please stay tuned for the final topic of this mini-series, which will discuss a holistic preventative approach. In an ideal world, we can avoid any need for interceptive orthodontic treatment. Looking forward to sharing some interesting information on this topic!