Jaw Position and Lateral Lisp

By Pam Marshalla

Q: I have a student with a lateral lisp whose does not have proper jaw alignment. The jaw at rest and during speech is moved over to the right. My thoughts are that the misalignment of the jaw is causing lateralization of the sibilants. Is this correct? What are your thoughts?

You are right. The jaw has to be in a stable midline position to produce a correct midline sibilant. I divide lateral lisps into several categories according to whether the jaw or the tongue are in error:

  1. Jaw Lateralization Lisp: Lateral lisps that are caused by jaw lateralization left or right. In this case the tongue is still creating a midline groove, but the sound is going out tot the side because the jaw is shifting that way.
  2. Unilateral Lisp: Lateral lisps that are caused by misplacing the tongue groove to the left or right. The jaw is still in a stable midline position. The cheek pulls out of the way on the side to which the air is directed.
  3. Bilateral Lisp: Lateral lisps that are caused by elevating the midline of the tongue so that the air escapes out both left and right sides. The jaw should kept stable at midline. The cheeks pull laterally on both sides to allow the air to escape on both sides simultaneously.
  4. Omni Lisp: Those that are made with no tongue groove at all, and by articulating no part of the tongue against the palate. The jaw is at midline. The airstream escapes out the entire front of the mouth from L to R. It sounds lateral because some of the sound is.
  5. Any combination of the above.

Your job in the assessment is to determine whether the jaw is moving to one side (a movement problem), or whether a malocclusion is causing the jaw to sit to one side (a structural problem).

Movement Problem

If the jaw is simply moving to one side, you can stabilize it by having him bite with the molars on to a straw or coffee stirrer. Use your hand to move the jaw into position as the child bites. He then can learn to make his sound with the jaw in correct position. Then teach him to hold the position correctly with the stick out of the mouth.

Structural Problem

A malocclusion is, as you know, a structural problem. The solution is to fix jaw structure with orthodontia or surgery. In cases where the jaw cannot or will not be fixed with orthodontia or surgery, we teach the client to make the best sound he can, given his structure. Van Riper called this the process of teaching “compensation.”

4 thoughts on “Jaw Position and Lateral Lisp”

  1. Hello! Thanks for the info. I have a first grade student who has both a frontal lisp for S/Z and a lateral lisp for CH/SH/J. The problem is that it is both structural (malocclusion) and movement. He has no overbite so teeth meet, therefore the S/Z for frontal. Then he moves the jaw to the R for CH, SH, and J. Does the structural problem need to be fixed before school speech therapy should begin? Thanks!

    1. Kimberly, I am sorry to inform you that Pam Marshalla passed away in 2015. I have asked one of Pam’s contemporaries and leader in the field, Robyn Merkel-Walsh, MA, CCC-SLP/COM, to help answer your question and below is her reply. Thank you!


      This is an excellent question for many to learn from.

      This student fits the classic profile for an Orofacial Myofunctional Disorder. What is important to understand is the artic errors are merely a symptom of a larger issue. What is important here is an in depth assessment of the orofacial complex to include : 1) hard tissue 2) soft tissue to include the oral frena 3) oral motor praxis 4) oral phase feeding to look at mastication, bolus collection and swallowing.

      We usually work on function and structure simultaneously rather than wait. For example work on jaw-lip-tongue dissociation and the orthodontist works on palatal expansion. In some cases , therapists prefer to wait until after phase 1 of orthodontia but I do not. It is also possible this child has a tongue tie.

      Here are some resources:


      online courses:

      Robyn Merkel-Walsh MA CCC-SLP/COM®
      Licensed Speech Pathologist
      Certified Orofacial Myologist®

  2. Hello I have a lateral lisp and it tends to get really annoying. I don’t know how to fix it, is there surgery for the lisp?

  3. My grandson aged 17 months has a lateral production of a, sh etc. . Difficult to assess at this age re jaw alignment etc. He has a dummy which I am concerned about. Any thoughts? I am a retired speech pathologist but have never treated or advised re management of children at this age.

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