Tri-Valley Orthodontics Clinical Spotlight: Early “Underbite” Correction

This week’s Clinical Spotlight is on Early (Phase I) Correction of an “underbite” (or crossbite) in children with Facemark Treatment.  Early and proper diagnosis of this key issue by an orthodontist goes a long way towards preventing irreversible damage to the teeth & gums due to this unfavorable bite and improves future prognosis.

An “underbite” or anterior cross-bite is when the lower teeth are positioned in front of the upper teeth, creating an unfavorable biting pattern which can lead to premature wear of the teeth, gum recession, and trauma.  Often, we see “underbites” in conjunction with a Class III Malocclusion (Bite).  This is when the lower teeth/jaws are unfavorably positioned forwards relative to the upper teeth/jaws – if pronounced this is often a familial growth pattern, which can worsen until growth is complete. If severe, a Class III growth pattern will necessitate surgical correction after maturity.

Early treatment (Phase I Treatment) of an anterior crossbite is recommended as this abnormal bite pattern can not only damage the involved teeth & gums, but also introduce asymmetry and hinder normal eruption & growth of the teeth and gums.

Facemask Correction:  Facemark treatment is very effective if initiated at an early age – generally before the age of 10.  If worn consistently the facemask is designed to move the upper jaw and molars forward to correct your “underbite”. This helps to both balance your profile, prevent excessive Class III growth and correct your anterior crossbite.  Facemask Treatment is done in conjunction with an upper expander (RPE) since the Facemask connects to the RPE to induce forwards/downwards pressure to the upper jaws & teeth.  This forwards pressure works overtime to correct the anterior crossbite and improve a Class III skeletal or dental relationship during a period of active growth, before maturity.

Below are a few of our patients who had Early Phase I Treatment (average age 8-9 years old).  Treatment included an RPE + Facemark.  Average treatment time was 12 months.  


Tri-Valley Orthodontics is a private Family Orthodontics practice in San Ramon CA owned and operated by Dr Jesse Ko and Dr Anne Yoon – both Orthodontists.  Our practice is unique in that both Dr. Ko & Dr. Yoon, work alongside each other each patient day. This allows us to provide more hands on care directly from our doctors to our patients.  We provide metal, clear, invisible lingual braces and Invisalign for Kids, Teens and Adults.  Our initial consultations are always complimentary.  For more information Call or Text us at (925) 272-7868, or email

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