by Merle Loudon

(Original article first published in “The Functional Orthodontist” in May/June 1987. Subsequently re-published in “Cranio-View” in February 1993. The version  produced herein has been edited by Cranio-View to emphasize the auditory advantages of Vertical Dimension Primary Molar Buildups for the benefit of non-dental readers, especially Hearing Therapists and members of the RNID.)

Definitions:

Primary molar:  “Baby” molar tooth, normally shed naturally at about 10 – 12 years of age.

Buildups:  A method of increasing the anatomical and functional height of a tooth or teeth artificially with an adhesive white tooth filling material. Can be used in the adult as well as primary dentition.

Gelb 4-7 Position: Theoretical ideal position for the mandibular condyle in the glenoid fossa in the closed position. Described by Dr Harold Gelb DDS of New York.

TMJ: The temporomandibular joint.

Maxilla: Upper jaw

Mandible: Lower jaw

Orthodontic treatment:  The correction of dental (i.e. tooth) mis-alignment.

Functional treatment: The correction of skeletal mis-alignment of the two jaw bones.

Class I and Class II occlusion: Orthodontic classification of relationship between the teeth and/or upper and lower jaws; Class I is normal, Class II is retrognathic (small lower jaw).

Division 2: Refers to retroclined incisors, which may tend to displace the mandible backwards.

Overbite: Refers to the vertical overlap of the closed incisor teeth, normally 10 – 15%. 100% overbite means the lower incisors are completely hidden by the uppers.

Retro-discal space: Refers to the space posterior to the articular disc of cartilage within the TM joint capsule.

Since primary molar buildups were introduced in the early 1980's, many benefits have been recognized.  While time proves or disapproves many techniques, Vertical Dimension Primary Molar Buildups (VDPMB.'s) have proven to be a very effective and safe way to correct vertical dimension, with a long list of excellent and lasting healthful changes.

Now, for the first time, we will evaluate the many thousands of primary molar buildups which have been performed over the last five years.  Are Vertical Dimension Primary Molar Buildups safe?  What beneficial results have we been able to achieve?  Are there any newly discovered advantages?  The answer to all of these questions seems to be a universal "yes." In the following pages we will examine some new and positive utilizations for Vertical Dimension Primary Molar Buildups.

In the original VDPMB. article (The Functional Orthodontist, Vol. 4, No. 3, May, June 1987), many advantages to the patient were listed.  These included:

(A) Enabling the lower first permanent molars to erupt to the proper vertical position, thereby moving the condyles from a retruded position to a more normal 4-7 (Gelb) condylar position, or centered in the glenoid fossa (Witzig position).

(B) Change of the resting tongue position from a posterior lateral tongue splinting position to a bisecting Class I "rest position."

(C) Repositioning of the mandible forward 1 to 1.5 mm. on most Class II Div 2 patients within 2 to 3 weeks. This results in retruded condyles being set free to advance to a more normally-centered physiological position.

(D) A second advancement of the mandible in some cases, occurring 4-8 weeks after placement of primary molar buildups.  This may result from the change in resting tongue position; forward tongue posturing; a better blood circulation posterior to the condyle in the neurovascular zone, and/or a better release and circulation of growth hormones to the condylar area.

(E) The natural widening and forward development of the mandible due to the change in position and resting pressure of the bisecting Class I tongue-position.

(F) A "balance" of muscle forces (tongue inside vs. buccinator and oblicularis oris muscles outside) which creates a balanced growth of both the maxillary and mandibular arches in all three planes.  In many patients this changes both position and growth from a Class II development to a Class I molar position and growth pattern.

(G) Early correction of the vertical position of the mandible, facilitating any functional and fixed orthodontic therapy which may be necessary in the future. Functional treatment may be started as soon as the mandibular first permanent molars get to the proper vertical dimension height.

Results have been documented repeatedly and consistently since my original articles on Vertical Dimension Primary Molar Buildups.  For the past three years the input I have been receiving from other dentists about VDPMB's has been both supportive and encouraging.  We have assembled information on approximately 250 Primary Molar Buildup cases to date.  Although it is premature to list results of any complete study since the lifespan of buildups does not exceed six years, shorter term studies have indicated very few drawbacks.  Information received suggests that the many advantages to the treatment certainly outweigh the occasional disadvantages reported to date.

What is especially heartening is the discovery of effects which can be added to the list of benefits reported since the initial introduction of the VDPMB'S.

 

Healthcare Professionals:  to read more of the article, and others like it,  contact the editor  and become a member of The Cranio Group...