Foundation-First Management of an Adult Transverse and Sagittal Malocclusion: A Longitudinal Orthodontic Case Report

Foundation-First Management of an Adult Transverse and Sagittal Malocclusion: A Longitudinal Orthodontic Case Report

Michael O. Williams, DDS, PA* 1, Michael B. Guess, DDS, MS, MA 2
  1. Gulfport, Mississippi.
  2. El Dorado Hills, California
       *Correspondence to: Michael O. Williams. Gulfport, Mississippi.

Copyright.

© 2026 Michael O. Williams, This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the originalwork is properly cited.

Received: 27 August 2026

Published: 10 October 2026

 

 

Abstract

Background: Adult orthodontic treatment becomes substantially more demanding when a constricted or tapered maxillary arch, sagittal discrepancy, alignment problems, and vertical considerations must be managed simultaneously. Treatment sequencing may therefore be as important as appliance selection.

Case: An adult female patient, age 27 years 11 months at initial records, presented with generally balanced facial proportions, a tapered maxillary arch with limited transverse coordination, localized rotations and irregularity, a sagittal discrepancy requiring active correction, and increased but functional anterior overlap. The documented record extended from March 17, 2014, to December 5, 2016 (32.6 months). Early records show a fixed maxillary development appliance with selective alignment, followed by comprehensive fixed appliances and bilateral interarch coil-spring mechanics, then coordinated finishing.

Results: Serial records demonstrate broader and better-coordinated arch forms, substantially improved alignment, a favorable interarch relationship, functional overjet and overbite, preservation of facial balance, and a natural final smile. An observational educational difficulty index declined from 7.6/10 pretreatment to 1.3/10 at completion, an 83% reduction in residual treatment complexity. The final educational outcome grade was A− (92/100). These values are not official American Board of Orthodontics scores.

Conclusion: The case illustrates a clinically useful principle: reduce foundational and interarch complexity before asking finishing mechanics to perfect the dentition. In adults, this approach must remain biologically disciplined because expansion is often largely dentoalveolar and requires attention to periodontal boundaries. A strong result is demonstrated by coordinated improvement across multiple diagnostic domains and by transparent acknowledgment of what cannot be quantified without calibrated models and cephalometric tracings.

Keywords: adult orthodontics; transverse deficiency; arch development; sagittal correction; fixed appliances; treatment sequencing; orthodontic finishing; stability; case report.

Foundation-First Management of an Adult Transverse and Sagittal Malocclusion: A Longitudinal Orthodontic Case Report

Introduction

Orthodontic expertise is often most visible in the order in which problems are solved. A malocclusion that presents simultaneously with inadequate transverse coordination, a sagittal discrepancy, dental irregularity, and vertical considerations can become mechanically inefficient when all objectives are pursued at once. A more disciplined strategy is to identify the foundational problem, reduce it, then apply increasingly precise mechanics as complexity falls.

The transverse dimension deserves particular attention in adult patients. Nonsurgical maxillary expansion has been reported in selected adults, but the biologic response differs from that of growing patients and much of the correction can be dentoalveolar rather than skeletal. Handelman and colleagues documented clinically useful adult transverse changes with a Haas-type expander, while also emphasizing careful case selection and periodontal considerations.[1] These findings support the possibility of adult arch development but do not justify treating every adult transverse discrepancy with the same protocol.

Sagittal correction also requires evidence discipline. Systematic reviews of fixed functional and interarch Class II correction show that clinically useful sagittal improvement can be achieved, but the treatment effect is frequently dominated by dentoalveolar rather than large skeletal change.[2,3] Thus, the clinically meaningful question is not whether an appliance created a dramatic orthopedic effect, but whether it contributed to a favorable and maintainable interarch relationship without compromising the face, periodontium, or vertical dimension.

The present longitudinal case is instructive because the photographic sequence shows treatment complexity being removed in a recognizable order: early transverse foundation development, comprehensive alignment, active sagittal correction, and late detailing. The case also provides initial and final panoramic, lateral cephalometric, and frontal radiographic records. Because calibrated casts and formal cephalometric tracings were not supplied, the analysis intentionally separates what can be observed from what can be measured.

 

Case Presentation and Diagnostic Assessment

At the initial examination on March 17, 2014, the patient was 27 years 11 months old. The facial photographs demonstrated generally balanced adult proportions and a pleasant smile that were important to preserve during treatment. Intraorally, the maxillary arch appeared relatively tapered, transverse coordination was limited, localized rotations and alignment discrepancies were present, and the sagittal relationship warranted active correction. The anterior vertical overlap was increased but remained functional, and the mandibular arch showed mild irregularity. No calibrated digital models, direct millimeter arch-width measurements, or complete pretreatment-to-final cephalometric tracing dataset was available in the supplied archive. For that reason, the case is reported with qualitative and ordinal clinical assessments rather than invented linear or angular values. This approach follows the central discipline of case reporting: the narrative should reflect the evidence actually available.[4]

 

 
Treatment Objectives
  • Develop a broader, more physiologic maxillary arch form and improve transverse coordination within adult periodontal and dentoalveolar limits.
  • Correct the sagittal interarch relationship without compromising facial balance or producing undesirable incisor compensation.
  • Align and level both arches while maintaining control of anterior tooth position and vertical overlap.
  • Establish functional posterior intercuspation and clinically favorable overjet and overbite.
  • Finish with a natural smile, healthy-appearing tissues, coordinated arch forms, and an occlusion suitable for retention.

Treatment Sequence

The early treatment records document a fixed maxillary development appliance together with selective alignment. By approximately 2 to 3 months, the appliance remained active while the arch-form trajectory became broader and space distribution for alignment improved. Because the exact appliance prescription, activation schedule, and millimeter expansion were not supplied, the mechanics are described only at the level visible in the records.

By Progress 3 (November 3, 2014), comprehensive fixed appliances and bilateral interarch coil-spring mechanics were present. The subsequent sequence demonstrates ongoing sagittal correction superimposed on the developed transverse foundation. This is an important distinction: sagittal mechanics did not substitute for the transverse correction; they were applied after the foundation had begun to improve.

Later checkpoints show a steady shift from active correction to coordination and detailing. By Progress 8 and Progress 9, the dominant clinical task had changed from major discrepancy correction to finishing. The final debonded records were obtained December 5, 2016.

 

 
Treatment Results

The final records demonstrate preservation of facial balance with an attractive, natural smile. The maxillary arch is visibly broader and better coordinated, localized rotations and irregularity are substantially reduced, and the anterior and posterior interarch relationships are clinically functional. Overjet and overbite appear favorable in the photographic record, and the gingival tissues appear generally healthy.

The result is especially strong when judged across multiple domains rather than by anterior alignment alone. The most conspicuous improvement is transverse: the tapered maxillary form became broader and more coordinated. Sagittal correction was obtained without an obvious deterioration in facial balance. Vertical overlap remained functional, and the final smile reflects both alignment and improved arch coordination.

 

 
Quantifying the Reduction in Clinical Complexity

A useful teaching feature of this case is the visible reduction in residual treatment complexity. Using the same observational educational rubric applied across the longitudinal record, difficulty was estimated at 7.6/10 pretreatment, 4.4/10 at Progress 6, 3.6/10 at Progress 7, 2.8/10 at Progress 8, 2.2/10 at Progress 9, and 1.3/10 at the final record. This represents an 83% reduction from the pretreatment score to the endpoint.


These values should not be interpreted as a validated severity index. Their value is longitudinal: the same rubric shows that the case became progressively easier to finish rather than repeatedly losing and recapturing correction. In clinical terms, the treatment sequence converted a high-demand adult problem into a late phase dominated by detailing.

 
Radiographic Assessment Panoramic Evaluation

Initial and final panoramic radiographs provide an important longitudinal overview. The final image supports a generally favorable root-angulation impression and does not reveal a gross pathologic change in the publication layout. However, panoramic radiographs are not sufficient to produce a formal American Board of Orthodontics Cast-Radiograph Evaluation score by themselves. The ABO objective grading system requires standardized assessment of final casts or digital models in conjunction with the panoramic image.5

This distinction improves, rather than weakens, the case. A publication-quality report should state exactly which findings are supported by the record and which require calibrated confirmation.

 

 
Cephalometric and Frontal Radiographic Review

The lateral and frontal radiographs support a qualitative assessment of treatment direction. Facial balance appears preserved, no gross unfavorable vertical change is evident, the anterior dental relationship appears improved, and no gross skeletal asymmetry is apparent in the frontal comparison. These are observational statements only.

A true numerical cephalometric comparison requires image calibration, landmark identification, a defined analysis, and reproducible pretreatment-to-final tracing or superimposition. Because these elements were not supplied, SNA, SNB, ANB, Wits, mandibular-plane, incisor, and soft-tissue values are intentionally not reported. This prevents a visually enhanced radiograph from being mistaken for a calibrated tracing.

 

 
Why the Result Is Excellent

Calling a case excellent should require more than a pleasing final photograph. In this case, the designation is supported by five independent features.

  1. The foundation improved. The maxillary arch changed from a relatively tapered and poorly coordinated form to a visibly broader and better-coordinated form. This reduced the need to make the final fixed-appliance phase compensate for an inadequate base.
  1. The sagittal correction was integrated rather than isolated. Bilateral spring mechanics were used within a broader sequence that had already begun to address transverse form. The final interarch relationship appears functional without an obvious sacrifice in facial balance.
  2. The vertical relationship was controlled. The patient began with increased but functional overlap. The final record shows a functional overbite rather than a treatment-induced open bite or an obviously excessive deep bite.
  3. Finishing occurred after complexity fell. Late records show that treatment demands shifted from major correction to coordination, detail, contacts, overlap, and smile refinement. That transition is exactly what efficient sequencing should accomplish.
  4. The case is presented with evidence discipline. The report does not invent millimeter expansion, cephalometric change, or formal ABO scores. Instead, it identifies where calibrated models, original radiographs, and tracing data would be required. This transparency increases the credibility of the outcome.

 

Discussion

Adult transverse development: useful, but biologically different

The principal diagnostic lesson is not that every adult narrow arch should be expanded. Rather, the transverse problem must be recognized before the teeth are cosmetically aligned. Adult maxillary development is biologically different from expansion in growing patients. Handelman et al. reported nonsurgical rapid maxillary expansion in adults with useful transverse gains and long-term stability in selected cases, but much of the change was attributable to alveolar and dental displacement, underscoring the need to respect the periodontium.[1]

Long-term arch-form research also cautions against assuming that every treatment-induced width change will be maintained indefinitely. De la Cruz et al. found a tendency for treated arch form to move back toward the pretreatment configuration after retention.[6] BeGole et al. similarly emphasized the importance of arch form and long-term evaluation when premolar expansion is used.[7] These data strengthen the rationale for individualized expansion and retention rather than weaken the foundation-first concept: the width objective should be biologically appropriate and deliberately protected.

Sagittal mechanics: judge the clinical relationship, not the marketing claim

The exact brand, force level, and activation protocol of the bilateral spring system in this case were not documented in the supplied archive. Therefore, the case should not attribute a specific skeletal effect to a named appliance. Systematic reviews of fixed functional Class II treatment show that these appliances can improve sagittal relationships, with effects that are frequently more dentoalveolar than skeletal and with limited high-quality evidence for long-term skeletal stability.2,3 The final relationship and its compatibility with the face are therefore more defensible outcome claims than a presumed orthopedic mechanism.

 

Finishing: objective evaluation matters

The final record appears strong, but excellent orthodontic finishing should be examined systematically. Casko et al. established the ABO objective grading system using alignment, marginal ridges, buccolingual inclination, occlusal relationships, occlusal contacts, overjet, interproximal contacts, and root angulation.5 In the present case, photographs and the final panoramic image support several of these domains, but calibrated digital models were not supplied. The authors therefore characterize the finish as an A− educational clinical outcome (92/100), not as an official ABO score.

This distinction is important for readers. An A− clinical teaching grade communicates that the overall finish is strong while still recognizing that marginal ridges, buccolingual inclination, precise contacts, and other model-based details require direct measurement. It also models the kind of self-audit that improves orthodontic expertise.

 

Retention and long-term responsibility

Retention remains integral to any claim of orthodontic success. Long-term studies demonstrate gradual postretention change even after high-quality treatment. Al Yami et al. found that a substantial proportion of treatment correction was maintained 10 years after retention, but relapse occurred across multiple occlusal traits and was especially important early after retention.8 A recent Cochrane review likewise confirms that retention strategies remain necessary despite uncertainty regarding the superiority of individual protocols.9 The present archive does not supply the detailed retention design, wear schedule, compliance record, or long-term postretention follow-up needed to claim permanent stability. Accordingly, the appropriate conclusion is that the final result has favorable stability potential, with retention remaining essential.

 

Why This Case Matters for Orthodontic Expertise

This case is educational because it allows the clinician to ask a more sophisticated question than “Are the teeth straight?” The correct question is “Did the treatment reduce the right problems in the right order?” A less experienced reading of the case might focus primarily on the final smile. A more advanced reading recognizes that the final smile is the visible consequence of several prior decisions: preserve an already acceptable facial balance, develop the transverse foundation, maintain vertical control, add sagittal mechanics once the foundation is improving, and reserve late treatment for detailed finishing.

This sequence also provides a useful framework for case critique. When a final case is not ideal, the orthodontist should determine whether the limitation represents an unresolved foundational problem or simply unfinished dental detail. Those are not the same failure. Conversely, a spectacular alignment result should not be allowed to conceal an untreated transverse, sagittal, or vertical discrepancy.

 

Limitations
  • The report is retrospective and describes a single patient; it cannot establish superiority of a treatment philosophy or appliance.
  • Calibrated digital models or casts were not available for independent measurement of arch widths, crowding, contacts, marginal ridges, buccolingual inclination, or formal objective grading.
  • Numerical pretreatment-to-final cephalometric tracings and superimpositions were not supplied; skeletal and incisor changes are therefore described qualitatively.
  • The exact maxillary development appliance prescription, activation schedule, spring brand, force level, and compliance record require confirmation from the treatment chart.
  • The detailed retention protocol and long-term postretention record were not available.
  • Written patient consent for identifiable publication should be documented before journal submission.

 

Conclusion

This adult case demonstrates a clinically coherent progression from foundation development to sagittal correction to finishing. The final result is excellent because facial balance was preserved while arch form, alignment, interarch coordination, and vertical overlap improved together. The treatment record also shows a steady decrease in residual clinical complexity, allowing late-stage mechanics to concentrate on refinement rather than rescue. For the orthodontist, the transferable lesson is simple: diagnose the foundation before selecting finishing mechanics. Correct transverse and sagittal demands deliberately, protect the vertical dimension, and then grade the final dentition objectively. The strongest case reports do not exaggerate what treatment achieved; they make the treatment logic visible and define precisely what the records can prove

 

References

  1. Handelman CS, Wang L, BeGole EA, Haas AJ. Nonsurgical rapid maxillary expansion in adults: report on 47 cases using the Haas expander. Angle Orthod. 2000;70(2):129-144. doi:10.1043/0003-3219(2000)070<0129:NRMEIA>2.0.CO;2.
  2. Zymperdikas VF, Koretsi V, Papageorgiou SN, Papadopoulos MA. Treatment effects of fixed functional appliances in patients with Class II malocclusion: a systematic review and meta-analysis. Eur J Orthod. 2016;38(2):113-126. doi:10.1093/ejo/cjv034.
  3. Bock NC, von Bremen J, Ruf S. Stability of Class II fixed functional appliance therapy-a systematic review and meta-analysis. Eur J Orthod. 2016;38(2):129-139. doi:10.1093/ejo/cjv009.
  4. Gagnier JJ, Kienle G, Altman DG, Moher D, Sox H, Riley D; CARE Group. The CARE guidelines: consensus-based clinical case reporting guideline development. J Med Case Rep. 2013;7:223. doi:10.1186/1752-1947-7-223.
  5. Casko JS, Vaden JL, Kokich VG, et al. Objective grading system for dental casts and panoramic radiographs. Am J Orthod Dentofacial Orthop. 1998;114(5):589-599. doi:10.1016/S0889-5406(98)70179-9.
  6. De la Cruz A, Sampson P, Little RM, Artun J, Shapiro PA. Long-term changes in arch form after orthodontic treatment and retention. Am J Orthod Dentofacial Orthop. 1995;107(5):518-530. doi:10.1016/S0889-5406(95)70119-2.
  7. BeGole EA, Fox DL, Sadowsky C. Analysis of change in arch form with premolar expansion. Am J Orthod Dentofacial Orthop. 1998;113(3):307-315.doi:10.1016/S0889-5406(98)70302-6.
  1. Al Yami EA, Kuijpers-Jagtman AM, van 't Hof MA. Stability of orthodontic treatment outcome: follow-up until 10 years postretention. Am J Orthod Dentofacial Orthop. 1999;115(3):300-304. doi:10.1016/S0889-5406(99)70333-1.
  2. Martin C, Littlewood SJ, Millett DT, et al. Retention procedures for stabilising tooth position after treatment with orthodontic braces. Cochrane Database Syst Rev. 2023;5:CD002283. doi:10.1002/14651858.CD002283.pub5.