Too much thumb and finger sucking can also throw a child’s bite out of alignment
Little ones like to put things in their mouth: a favourite toy, puppy’s tail, grandma’s cell phone. Among their most-loved items are their very own thumb and fingers. However, parents often worry this may cause dental problems down the road.
“The primary concern is the movement of the teeth,” says Dr. Elizabeth Logan, a Halifax dentist who has additional training in working with children.
Fingers and thumbs can exert pressure on new teeth and those that have yet to come through. One of the key factors is the force of the pressure on the teeth. “The position of the thumb and fingers in the mouth is important,” says Dr. Logan. “Some children don’t rest their fingers on their teeth as heavily so there is less pushing.”
Another key factor is the length of time pressure is exerted. “It takes four to six consecutive hours to cause tooth movement,” says Dr. Logan, who has served as a clinical instructor in the faculty of dentistry at Dalhousie University.
One condition called anterior open bite is caused by the upper and lower teeth not closing properly. One cause for this is thumb sucking. “The thumb actually pushes the teeth back in when they are trying to erupt,” explains Dr. Logan.
Too much thumb and finger sucking can also throw a child’s bite out of alignment. In some cases, the upper incisors, those teeth in the front of the mouth, are pushed out towards the lip while the lower incisors are pushed back toward the tongue. “This does affect the bite,” says Dr. Logan. “It leads to a greater distance between the upper and lower incisors.”
This can be corrected naturally, she adds. “If the habit stops before the permanent teeth are in place, the tongue, lips and cheeks will help move the teeth back into proper position.”
Issues related to thumb sucking can have long-term implications. “All of these problems can affect function and aesthetics and may require orthodontics later in life,” cautions Dr. Logan, who has limited her practice to children.
Easy does it
Despite the potential problems, she says, there is no need to rush to remove little fingers and thumbs from mouths. “You don’t want to intercept too early. Both parents and the child should want to end the habit.”
Many children spontaneously decide their thumb or fingers are of less interest as they age. Friends at school may also be a motivator. If children are still sucking their thumb after the permanent teeth are in place, around age six, the issue requires attention. Once the permanent teeth arrive, sucking may cause problems with the proper development of the mouth and alignment of the teeth. As well, it can lead to changes in the roof of the mouth.
Many parents are concerned that finger sucking is linked to a child’s emotional well-being and stopping the habit can create other problems. “This is not the case,” says Dr. Logan. “Thumb sucking is a natural reflex for children. Some actually start while they are still in utero.”
She notes that even though it has been shown that ending a finger habit doesn’t affect a child’s emotional well-being, efforts to end the habit shouldn’t be initiated in a difficult or stressful period in a child’s life, such as moving to a new school.
Kids and parents looking to end thumb sucking have many options to support them along the way. Children can often meet with the dentist, who can explain why they suck their thumb, the possible problems this may cause, and how they can stop. “This is often helpful for kids experiencing peer pressure,” says Dr. Logan.
Reminder therapy is another option. Here the child puts a bandage on their thumb or a tube sock over their hand as a visible prompt not to put thumbs and fingers in their mouth. A bitter substance, such as vinegar or lemon, can also help kids break the habit. Dr. Logan says, “We encourage parents to tell their kids this isn’t a punishment. It’s just a reminder,”
Rewards also work. Children can put a sticker on a calendar for each day they don’t suck their thumb and after so many days they get a special treat or a small gift.
For children who don’t even realize they are putting their thumb in their mouth, such as when they are sleeping, adjunctive therapy may be useful. This involves placing a bandage around the elbow to prevent sucking, but it doesn’t cause any discomfort to the child.
There are also more permanent options, such as a quad helix, an appliance for the upper teeth cemented in the mouth using bands, that can correct a cross bite and make thumb sucking difficult.
“There are lots of options parents can use to help their child stop thumb sucking,” says Dr. Logan. “To find out what might work best for you, talk with your dentist and explore the alternatives.”