All About Orthodontics

LindsayOrthodontic treatment can correct a variety of malocclusions, or misalignments of teeth. Orthodontics addresses issues of crowding, spacing and inappropriate bites, like openbite, overbite and underbite.

Orthodontic technology has produced a variety of different ways to correct malocclusions. For every misalignment, there is one or several appliances that help to restructure your bite. The most commonly well-known appliances are called braces, but these are often used in conjunction with other appliances to help shape your palate or jaws.

Here's a run-down of the different technologies your orthodontist may prescribe for your treatment.

Braces | Invisalign | Acceledent | Expanders | Space Maintainers | Class II: Pendulum & DMJ | Carriere | Herbst | Headgear | Class III: Facemask | Bollard Plates | Orthognathic Surgery | Retainers


Braces move misaligned teeth into a new position by applying constant subtle pressure on the teeth. Your orthodontist will adjust your braces every 6-8 weeks so that the movement of your teeth is gentle and gradual. Traditional braces work through the combination of bands, brackets, archwires and elastics. Due to the advancement of orthodontic technology, braces can be metal-color or clear and come with over 20 colors!

braces before after

Braces, treated at Chestnut Dental


Instead of traditional metal braces, it is also possible to align teeth using clear plastic aligners that look like retainers or bleaching trays. Clear aligners are produced by many companies, but at Chestnut Dental we only use aligners made by Invisalign, a company with a big head start on the competition.

Invisalign treatment used to be only for adults, but the technology has caught up so that there are many treatments Invisalign does as well as braces, and a few areas where it has surpassed braces.

To learn more, please visit our Invisalign page.


AcceleDent is a product used at home daily along with braces or Invisalign to speed up orthodontic treatment. It does not change the treatment outcome, it reduces the overall time in treatment.

To learn more, please visit our AcceleDent page.


Palate expanders are used to correct crossbites and also create more room in your mouth by expanding your upper palate; this corrects the crowding that leads to over or under-eruption of misaligned teeth.

When patients are still growing, the connective tissues between the left and right halves of their upper jaws are very responsive to expansion. The expander rests near the roof of your mouth and uses metal wires to hold your upper molars and push outward. This outward pressure spreads the left and right halves of your jaw – the halves of your jaw are biologically intended to do this, so the process is painless. New bone grows between the spread halves of the jaw, resulting in an increased width.

As with braces, pushing on your teeth must be done gradually, but with an expander these adjustments are made through a key inserted into the appliance and turned; turns of the key widen the appliance, which applies further widening pressure to your upper jaw. Expanders are typically worn 6-9 months.

View our video on how to turn the palate expander:

Space Maintainers

Baby or primary teeth are vital to your child's current and future dental health; they promote normal development of the jaw bone and muscles, preserve space for the eruption of permanent teeth and guide permanent teeth into their proper positions. If your child loses baby teeth due to injury or decay, we may recommend space maintainers, or spacers.

Space maintainers are small and unnoticeable in appearance, customized to fit your child's mouth. They stabilize the remaining teeth by preventing movement until the permanent tooth erupts, taking its proper place in the jaw.

The Lower Lingual Arch is one specific type of space maintainer that holds molars in place with a metal archwire. This keeps the molars from drifting forward and blocking the space where permanent teeth will eventually erupt. The duration of wear varies. Your orthodontist will monitor the eruption of new teeth and make adjustments. The Lower Lingual Arch is usually removed following the eruption of all the permanent teeth. Children should be monitored, especially during brushing and flossing, to ensure that they do not push or tug on the space maintainer with their tongue or fingers.

For the Lower Lingual Arch specifically, it may hurt to chew for the first day or two. We recommend a soft diet initially; you may take Advil or Tylenol to relieve discomfort. It's important that you brush and floss daily and clean thoroughly around the bands that connect the molars and the tongue-side wire; this will prevent the formation of cavities or infection of the gums.

Class II Orthodontic Treatment

One of the most common problems orthodontists treat is the misalignment that occurs when the upper teeth protrude beyond the lower teeth, known as a class II bite or more commonly, an “overbite”. For patients with a class II bite, braces, elastics, and an appliance are typically used together to correct the bite. Certain appliances are more appropriate than others depending on the type of misalignment and the severity. Below we describe the appliances we use at Chestnut Dental to treat a class II bite.

Pendulum and Distal Molar Jet (DMJ)

The pendulum appliance and distal molar jet (DMJ) are modern alternatives to orthodontic headgear. These appliances are used to correct an arrangement in which the upper molars rest in front of the corresponding lower molars. The metal wires of the appliance push the upper molars into a better position relative to the lower molars. When this appliance is used in conjunction with a palatal expander to widen the entire upper palate, we call it a Pendex or DMAX.


For patients with asymmetric tooth relationships, erupting adult teeth, or other bite discrepancies, the Carriere appliance can be used with elastics and braces to correct the bite. One advantage for the patient is it reduces the time in braces for the upper arch by about 6 months, making it easier for the patient to floss and brush that area. However, the appliance is not spring activated like the DMJ, so it requires very good elastic wear by the patient.

Herbst Appliance

For patients with a large “overbite” (top front teeth ahead of lower teeth), a Herbst appliance might be more appropriate than a DMJ or Carriere appliance. When we see a patient with the upper teeth protruding significantly, it is likely due to a combination of the upper teeth being too far forward and a small lower jaw that is further back than it should be. For these patients, we want to encourage the lower jaw to catch up in growth. The Herbst appliance helps this happen.

herbst appliance before after

Braces with Herbst Appliance, treated at Chestnut Dental

The Herbst appliance is a functional appliance that holds the lower jaw in place and prevents it from moving backward. Your jaws will shift and grow to accommodate the new positioning. Even though the Herbst appliance constrains the movement of your jaw, opening and closing movements still occur easily.

At the outset of treatment, the Herbst appliance – as with all fixed functional appliances – will create a feeling of fullness in the mouth, and speaking may feel awkward. Reading aloud will help you get used to the new positioning, and ordinary speech will return quickly. You may also notice more saliva than normal, but this will decrease as you become accustomed to the appliance. If any other discomfort occurs due to the Herbst appliance, it will be a sore area on the inside of the cheeks; in this case, call to make an appointment for readjustment.


Headgear is often used to correct a bite in which the upper teeth protrude horizontally over or past the bottom teeth. It does this not by pulling or pushing at the lower jaw but by slowing the development of the upper jaw so that the lower jar can catch up. This removable appliance attaches to your upper molars and pulls them straight up or back with a strap worn around your head or neck. Headgear has been used successfully by orthodontists for generations. At Chestnut Dental we typically only use it for young, growing patients for whom the other class II appliances might be too cumbersome.

The key to success with headgear is consistency: headgear must be worn a certain number of hours per day.

Class III Orthodontic Treatment

When the lower teeth protrude beyond the upper teeth, that is known as a class III bite or more commonly, an “underbite”. For patients with a class III bite, the underlying relationship of the jaw bones usually needs to be treated in addition to the tooth positions. Specifically, growth of the upper jaw must stimulated to match the lower jaw following a protocol that starts as soon as the underbite develops and lasts until jaw growth is done.

Facemask- Ages 7-10

Photo credit:
Kircelli, AJODO, 2008

Patients have an orthodontic “underbite” when their lower front teeth are ahead of their upper front teeth, opposite the ideal relationship. If this is caused by tooth position alone, then braces will fix the problem. However, the cause can also be related to jaw bone position: the lower jaw is growing faster than the upper jaw. For these patients, a combination of braces and facemask is used to correct both the tooth position and the jaw bone position.

Facemask treatment can last anywhere from 12 to 18 months. The patient typically has braces on their teeth, while wearing the facemask only at night when they’re home. This accelerates the growth of the upper jaw by about 3mm, helping it catch up with the lower jaw to correct the crossbite.

Bollard Plates- Ages 11-14

bollard plate front view
Photo credit:
Nguyen, AJODO, 2011

If a patient completes facemask treatment and still needs additional correction, or they first saw an orthodontist after age 10, then correcting the growth rate of the jaws can be done using Bollard plates. The goal of Bollard plates is similar to the facemask: stimulate growth of the upper jaw to catch up with the lower jaw. One big difference between the two treatments is that the facemask applies pressure to the upper teeth, which in turn apply pressure to the upper jaw, while Bollard plates apply pressure to the upper jaw directly. One isn’t better than the other; there are certain instances and ages when each technique is more appropriate.

Orthognathic Jaw Surgery- Ages 16+

For a non-growing patient with a large lower jaw, the orthodontist places braces or Invisalign to align the teeth, then the oral surgeon surgically repositions the jaws so the teeth and bones fit together.

Facemask and Bollard plate therapy are used in growing patients and often reduce the need for orthognathic jaw surgery. However, if a patient’s lower jaw continues to grow after those treatments, or we first meet the patient after they are done growing, then jaw surgery is recommended. Below you can see a before/after for a patient who recently completed braces and jaw surgery treatment at Chestnut Dental.

Orthognathic Jaw Surgery + Invisalign

In the Boston area, the orthodontists at Chestnut Dental provide a unique treatment: jaw surgery with Invisalign instead of braces. Working closely with the surgeons at Children’s Hospital, we developed a protocol that replaces braces with Invisalign trays during the pre- and post-surgical orthodontics. Jaw surgery is typically done in the late teens or early 20’s, so Invisalign is a welcome option for certain patients. Below you can see before/after for a patient who completed Invisalign and jaw surgery treatment at Chestnut Dental.



Once your orthodontic treatment is complete we provide retainers to maintain your treatment result.

For young patients we use removable Hawley retainers made of metal and plastic because they can be adjusted as the baby teeth fall out and adult teeth erupt. This type of retainer can also be made with springs for teenagers and adults to correct a single tooth that has moved out of position.

For nearly all our teenage and adult patients we use removable essix retainers. These are virtually invisible clear plastic retainers molded to fit your teeth. Also for our teenage and adult patients we bond a wire behind the lower or upper front teeth to hold these teeth in place. The front teeth are the most likely to shift, so after treatment we use the combination of permanent wire with removable retainers to provide the greatest chance for long-term success.

To learn more visit our page on orthodontic retainers.