Maxillary Deficiency by Dr. Chad Foster

Start Discussion More by this author (8)
Maxillary Deficiency

by Dr. Chad Foster

Maxillary deficiency is most commonly identified and discussed in orthodontics as a transverse problem; however, many growing Class III patients demonstrate maxillary deficiency in all three planes of space: transverse, anteroposterior, and vertical.

The growing patient with a deficient maxilla commonly demonstrates a complex pattern of skeletal underdevelopment rather than an isolated transverse discrepancy. James A. McNamara Jr. emphasized that maxillary constriction is frequently associated with A-P maxillary deficiency as well as deficient vertical facial proportions, particularly in skeletal Class III malocclusions.1

As orthodontists, our diagnostic focus is naturally biased toward teeth and occlusion. Through that lens, transverse discrepancies are typically more visually obvious and therefore readily treated. We are quick to identify the more obvious deficient transverse component: posterior crossbite, narrow maxillary arch form, or crowding. The vertical and A-P deficiencies of the maxilla, however, are often more subtle and therefore underdiagnosed. Consequently, many patients who initially present with an obvious transverse discrepancy are, in reality, deficient in all three planes of space.

A-P maxillary deficiency often presents clinically as a Class III malocclusion with anterior crossbite. The associated “relative” excessive chin projection in these patients frequently draws the clinician’s attention, causing the problem to be misdiagnosed primarily as mandibular excess rather than an actual maxillary deficiency. Said another way, it can be easier to errantly see these patients as “chin excessive” when often they are actually midface deficient.

Vertical maxillary deficiency (VMD) can be quite subtle and is often the most overlooked of the three planes. In these patients, decreased lower facial height, deficient incisor display, and inadequate vertical development of the maxillary alveolar process are less easily diagnosed compared to an obvious posterior or anterior crossbite. Furthermore, VMD directly acts to worsen the severity of the malocclusion in the other two planes. When the maxilla is “shorter,” the mandible rotates counterclockwise (up and forward). This moves the mandibular arch anterior (1) into a worsened Class III malocclusion and (2) advances the mandibular arch into a more narrow portion of the maxillary arch, which worsens the transverse malocclusion. Fortunately for these same VMD patients, normalizing vertical allows clockwise mandibular rotation to naturally decrease the degree of both the A-P and transverse occlusal burdens.

MARPE for A-P and transverse skeletal correction
The introduction of miniscrew-assisted rapid palatal expansion (MARPE) has significantly expanded the orthopedic potential of nonsurgical treatment in adolescents. Unlike conventional tooth-borne expanders, MARPE transfers expansion forces directly to basal bone through skeletal anchorage, increasing orthopedic effects while minimizing dentoalveolar tipping.2,3

Even just beyond the mixed dentition stage, at approximately 11 to 13 years of age, the circummaxillary sutures still retain meaningful orthopedic responsiveness, particularly when combining MARPE with reverse-pull headgear.3 This can be an ideal period to orthopedically address a three-plane-deficient maxilla in a single phase of orthodontic treatment. Maino et al. demonstrated that a hybrid skeletal expander combined with facemask therapy produced significant orthopedic A-P advancement of the maxilla in patients with a mean age of approximately 11 years, with minimal dentoalveolar compensation.4

In select patients, we can also nonsurgically address the vertical maxillary deficiency component. Controlled extrusion of the maxillary dentition during orthopedic correction may facilitate vertical alveolar development as the dentoalveolar process erupts downward. As the teeth erupt, alveolar bone follows, effectively increasing the vertical dimension of the maxilla while improving lower facial height, smile display, and facial balance without surgery.

A novel MARPE application to address the third plane of deficiency
In this article, I would like to introduce a custom MARPE variant that is intended to address maxillary deficiency in all three planes of space.

Brodie was 11.5 years old and in full permanent dentition when he presented with his mom (Figure 1). Their chief complaint was his anterior underbite. He also suffered from chronic cheilitis, which was secondary to his lower lip habitually trapping/sucking his upper lip. Importantly, they stated there was no family history of a chin forward/underbite predisposition. Mom had taken Brodie to two other orthodontic consults in the recent past and stated both recommended that he “should not be treated until he was done growing.”

Diagnosing from outside-in, Brodie shows a classic short face presentation: short lower 1/3 facial height, relative excess chin prominence, a more “square” frontal facial form, compressed lips, compressed smile window (smiling interlabial gap), and deficient vertical upper incisor display. Intraorally, he showed a complete anterior crossbite, posterior right crossbite, and minimal crowding. There was a presence of a CO-CR slide, and when he slid down and back into CO, he could just barely come edge to edge with his incisors.

I explained to Brodie and his mom that it was apparent that his maxilla was, in varying degrees, deficient in all three planes of space. I proposed a unique treatment but emphasized that my plan did not rule out the possibility that future unfavorable mandibular growth could necessitate additional treatment years from now and possibly jaw surgery.

For Brodie, I designed a novel custom MARPE that aimed to address all three planes of his maxillary deficiency. The expansion component would obviously address the transverse deficiency. Facemask therapy would be added to attempt maxillary protraction. This combination is a common practice for these two maxillary deficiencies. Brodie’s MARPE would be unique, however, in how it would address the deficient vertical component, which in my opinion is very often overlooked and unfortunately unaddressed in these types of patients.

In the MARPE design (Figure 2), the double tube slots of the U6s were positioned very occlusal to where the other maxillary brackets would eventually be placed (4 mm lower than that anticipated slot level). We began initially with expansion, facemask therapy at night, and an 0.014 NiTi wire only in the mandibular arch. Large bite turbos were placed on the occlusal of the U6s to open his vertical/MPA. In short, (1) the bite turbos set the facial height goal (new vertical/MPA position) that I felt was appropriate, and then (2) the TAD-anchored U6s extrude all the maxillary dentition mesial to them to fit the occlusion to that new vertical facial height goal, locking it into place.

After one month of daily expansion activations, a significant midline diastema was present, and we placed an 0.014 NiTi wire in the maxillary arch (Figure 3). Figure 4 shows the disclusion from the bite turbos and the up-close engagement of the maxillary archwire into the occlusally displaced slot of the TAD-anchored maxillary first molars. The U5-5 were now set to be erupted into the new vertical/MPA position.

Four and a half months into treatment, with light NiTi wires only, that eruption had meaningfully occurred (Figure 5 shows progress records to that point and Figure 6 an up-close comparison view). It is important to note that he has not been assigned any Class III elastics or inter-arch elastics of any kind at this point. Our focus is on orthopedic movement and dental extrusion. Figure 7 shows the striking facial change over that time period. Of particular note are the visible macroaesthetic (face) and miniaesthetic (smile) changes that were impacted by the new vertical/MPA position: increased lower 1/3 facial height, decreased chin projection, lip decompression, increased ovoid taper to his frontal facial profile, increased height of his smile window, and increased vertical incisor display. Also of particular note, Brodie no longer suffers from the chronic cheilitis of his upper lip, which amazed him and mom.

Looking ahead into treatment, after the eruption and occlusion of the U5-5 settle and facial height has been maintained, the MARPE arms connecting to the U6s will be removed. The palatal auxiliary loop wires from the MARPE will then be bent and bonded to the U4s and U5s to fixate these extruded teeth. Then the bite bumps and bands on the U6s will be removed, U6 brackets placed at a normal position on these teeth, and they will be likewise erupted to match the occlusal plane and vertical position of the other maxillary teeth. On a side note, I think the palatal auxiliary arms could have been designed better with more robust/thicker wire to aid their future use, but we will see how further progress goes.

This case represents progress records only, and I look forward to updating final records upon completion. In part 4, the final article of my “Short-Face Patients” series (Orthotown March 2025), I presented a novel palatal TAD eruption protocol for VMD patients. Brodie’s case represents my first, and imperfect, iteration of combining my VMD TAD eruption approach with MARPE.

I believe that a significant percentage of maxillary deficient patients we treat are truly deficient in all three planes of space. Our ability as dentofacial orthopedists to better treat two of those deficient planes with MARPEs (transverse and A-P) is well accepted and growing in evidence. My hope is that our future appliance designs, when appropriate, will also address vertical maxillary deficiency. The results of such changes are truly life-changing for our patients. 
Maxillary Deficiency
Fig. 1
Maxillary Deficiency
Fig. 2
Maxillary Deficiency
Fig. 3
Maxillary Deficiency
Fig. 4
Maxillary Deficiency
Fig. 5
Maxillary Deficiency
Fig. 6
Maxillary Deficiency
Fig. 7

References

1. McNamara JA Jr. Maxillary transverse deficiency. Am J Orthod Dentofacial Orthop. 2000;117(5):567-570.
2. Kapetanovic A, et al. Efficacy of miniscrew-assisted rapid palatal expansion in late adolescents and adults: A systematic review and meta-analysis. Eur J Orthod. 2021.
3. Moon W. The efficacy of maxillary protraction protocols with the microimplant-assisted rapid palatal expander (MARPE). Prog Orthod. 2015.
4. Maino G, et al. Skeletal and dentoalveolar effects of hybrid rapid palatal expansion and facemask treatment in growing skeletal Class III patients. Am J Orthod Dentofacial Orthop. 2018.

Author Bio
Dr. Chad Foster Dr. Chad Foster is Orthotown’s editorial director, a board-certified orthodontist and owner of Butterfly Orthodontics in Phoenix. A graduate of Chapman University, he earned a Doctor of Dental Surgery and a master’s degree in craniofacial biology and completed his orthodontic residency at the University of Southern California. Foster writes and lectures internationally on the topic of orthodontic aesthetics.


Orthotown Magazine
June 2026
Orthotown Magazine June 2026 Read Current Issue Read Archived Issues
Sponsors
Site Menu
Message Boards Magazine Continuing Education Podcasts Blogs Classifieds News Events Townie® Poll Ebooks Townie Choice Awards
Company Info
Contact Us Advertise With Us Howard Farran DDS, MBA Policies and Agreements
Site Help
The Orthotown Team, Farran Media Support
Phone: +1-480-445-9710
Email: support@orthotown.com
©2026 Orthotown, a division of Farran Media • All Rights Reserved
9633 S. 48th Street Suite 200 • Phoenix, AZ 85044 • Phone:+1-480-598-0001 • Fax:+1-480-598-3450