MBT vs Roth Prescription: Less Tip, Similar Final Results

A bracket prescription is the set of tip, torque and in-out values built into each bracket of a preadjusted (straight-wire) appliance. Roth and MBT (McLaughlin, Bennett and Trevisi) are the two prescriptions most clinicians meet first, and the question "which one is better?" comes up in every residency and every continuing education course. The short answer from the literature: the two differ in philosophy and in some values, mainly anterior tip and incisor torque, but the finished cases that have been compared show differences that are small or not clinically detectable. Bracket position, wire size and the mechanics you choose matter at least as much.

This guide explains what a prescription is, how Roth and MBT differ, what the comparative studies show, and why the values printed on a chart are not the values your patient receives. It is written for general dentists, residents and students.

MBT vs Roth at a glance

Tip totals: Rajesh et al., 2014. Torque moment: Mittal et al., 2012. Finished cases: Mittal et al., 2014, Moesi et al., 2011, Jain et al., 2013.

About the numbers. This article does not reproduce a tooth-by-tooth prescription chart. Neither our D.U. course materials nor the PubMed abstracts we could verify give the full per-tooth tip and torque values of Roth and MBT, and the values sold under the same name vary between manufacturers (see below). For the exact values of the brackets you use, read the manufacturer’s specification sheet.

What a bracket prescription is

The D.U. course materials describe tooth position in three orders:

• First order: the arch form and the in-out position of each tooth (labiolingual thickness of the bracket base).
• Second order: the mesiodistal axis, or tip (angulation) of the crown.
• Third order: the buccolingual inclination, or torque.

In standard edgewise, the clinician bends all three orders into the archwire. In a preadjusted appliance, they are built into the bracket. The course puts it simply: in edgewise the torque is bent into the wire, in straight-wire it is in the bracket slot. A review of anterior bracket choice makes the same point: preadjusted brackets carry torque, tip and in-out values that are optimized for average cases, and the individual tooth is then refined by wire adjustments, auxiliaries or a modified bracket position, including bracket inversion (Thickett et al., 2007).

The word "average" is the key. A prescription is a compromise designed for the typical tooth and the typical malocclusion. Boileau, as summarized in our course materials, presents both families of appliances on equal terms:

• Non-preadjusted brackets (Tweed-Merrifield, standard edgewise) require formable wires (steel, TMA), small sections and loops at the start, but allow continuous individualization and respect the arch form better.
• Preadjusted brackets allow low-modulus wires, early torque control and sliding without loops, but preformed archwires change the arch form at first and need individualization at the end of treatment.

Our D.U. teaches the Tweed-Merrifield technique on non-preadjusted brackets. Roth and MBT belong to the second family.

Where Roth and MBT come from

Both descend from Andrews’ straight-wire appliance, which was built around his six keys of normal occlusion: molar relationship, crown angulation, crown inclination, no rotations, tight contacts and a flat or slightly concave curve of Spee. Our course materials use these six keys as one of the finishing grids, alongside the Tweed occlusion.

Roth modified the original values. The course materials, citing Boileau, note that Roth was in favor of overcorrection, while others see it as a source of instability; Boileau reserves overcorrection for malocclusions that relapse easily, such as deep bites, palatally tipped upper incisors and open bites.

MBT was introduced later by McLaughlin, Bennett and Trevisi. It changed several values of the earlier prescriptions. The two changes that the studies below measure are a lower anterior tip and a different incisor torque. In a randomized trial of 30 Class I patients with four premolar extractions, the authors concluded that MBT "effectively addressed perceived inadequacies" of the Roth philosophy during the first phase of treatment (Talapaneni et al., 2012); the abstract reports the changes per group, but the sample is small.

Both prescriptions are sold in 0.018-inch and 0.022-inch slots, and the comparative studies mix both sizes, which complicates comparisons (Soboku et al., 2019; Chaudhary and Sharma, 2018).

The differences that matter clinically

Anterior tip and anchorage

Tip on the incisors and canines tips the crowns mesially as soon as a full wire is engaged, and every degree of tip consumes space and anchorage. In a prospective study of 10 Roth and 10 MBT patients, anchorage loss after leveling and aligning was greater with Roth. The authors attribute it to anterior tip, which they give as 27° in total for Roth against 20° for MBT, and they note that lacebacks and cinchbacks increase anchorage loss when posterior anchorage is not reinforced (Rajesh et al., 2014). The sample is very small.

Tip also uses arch perimeter. On a virtual model built from CBCT data, every prescription increased the anterior arch perimeter compared with zero angulation, from 0.28 mm at crown level and 3.19 mm at root level with edgewise values to 1.09 mm and 11.28 mm with Roth, the most angulated prescription tested (Pontes et al., 2014). The authors stress that the root-level effect needs further study.

In practice: with a highly angulated prescription in a crowded or extraction case, plan the anchorage before the first wire, and read our guide to orthodontic anchorage for the options.

Canine retraction

A split-mouth trial in 40 young adults with upper first premolar extractions bonded MBT brackets on one side and Roth brackets on the other, then retracted the canines with sliding mechanics on a 0.017 × 0.025-inch steel wire. Retraction was faster on the MBT side; after adjustment for time, the Roth side moved about 0.16 mm per month less (Attique et al., 2025). The difference is statistically significant but small, over three months only.

Incisor torque

With pretorqued nickel-titanium wires engaged in brackets on retroclined upper incisors, MBT brackets produced a significantly larger labial crown torque moment than Roth or edgewise brackets in a bench study (Mittal et al., 2012). This is consistent with MBT carrying more labial crown torque on the upper incisors than Roth.

Whether either prescription produces "normal" incisors is another question. A theoretical study compared the expected incisor inclinations of the Andrews, Roth, MBT and Ricketts torque values with several cephalometric norms. For the upper incisor, none of the systems reached any of the target inclinations, falling short by 6.8 to 10.5° for Roth and 11.8 to 15.5° for MBT; for the lower incisor, MBT agreed closely with the Ricketts and Björk targets (Zimmer and Sino, 2018). The authors conclude that common upper incisor torque values do not reliably achieve normal inclinations. The study is a geometric model, not a clinical trial, but its message matches the rest of the evidence: the final inclination is set by the treatment plan and the clinician, not by the prescription alone. Cephalometric targets for the incisors are covered in our Steiner analysis and mandibular plane angle and IMPA guides.

The smile

In a simulation study, the three prescriptions were applied virtually to the scanned upper arches of three women with Class I, II and III patterns, and 167 orthodontists, dentists and laypeople rated the smiles. Roth scored highest, MBT 4% lower and Ricketts 13.6% lower; profile smiles with excessively proclined incisors were judged unattractive (Kreichati et al., 2023). Three patients and simulated bracket effects are a narrow base.

What finished cases show

The comparisons of finished cases point in the same direction:

• Final inclination. On 40 laser-scanned post-treatment models (20 Roth, 20 MBT), there was no statistically significant difference in the final crown inclination of the upper central incisor, upper canine and lower incisor; the differences in torque values did not lead to clinically detectable differences (Mittal et al., 2014).
• Expert judgment. On the same kind of sample, nine experienced orthodontists rated incisor and canine esthetics, torque and tip. Bracket prescription had no effect on the score, and most judges could not tell which prescription had been used better than chance (Moesi et al., 2011).
• Objective grading. In 40 cases graded with the American Board of Orthodontics Objective Grading System, MBT cases scored 2.65 points better in total, mainly in buccolingual inclination and occlusal contacts. The authors judged the difference statistically significant but of little clinical significance, and concluded that treatment quality depends on the clinician’s judgment and experience (Jain et al., 2013).
• Measured angulation. In 30 patients treated with 0.022 MBT, 0.022 Roth or 0.018 Roth brackets, the only significant difference was the mandibular canine angulation (5.81° with 0.022 MBT, 9.07° with 0.018 Roth), and the authors saw no clinical influence on outcomes (Soboku et al., 2019).

All of these are retrospective or small studies, often from a single center. They do not prove the two prescriptions are equivalent; they show that no study has found a difference large enough to matter at the end of treatment.

Why the chart is not what the tooth receives

Slot play

A rectangular wire that does not fill the slot rotates freely before it engages the slot walls. A systematic review of in vitro studies measured this engagement angle in stainless steel brackets: in a 0.022-inch slot, from 18° with a 0.018 × 0.025-inch steel wire to 6° with a 0.021 × 0.025-inch wire; in a 0.018-inch slot, from 31° with a 0.016 × 0.016-inch wire to 4.6° with a 0.018 × 0.025-inch wire (Archambault et al., 2010). The review found the engagement angle larger than theoretical values. In other words, on a 0.019 × 0.025-inch working wire in a 0.022 slot, a sizable part of any torque value is never expressed. The difference between two prescriptions is often smaller than the play.

Manufacturing

An in vitro audit of eight commercial products sold as 0.018 Roth or 0.022 MBT found significant variations from the standard torque values in both groups; only some products did not differ from the standard (Chaudhary and Sharma, 2018). Two products with the same name may not deliver the same torque.

Bracket position

The D.U. course materials insist on this point: a bracket positioning error is an alignment error. Height changes the vertical position and the torque, because the labial surface is convex: a more gingival bracket on an upper incisor delivers less palatal root torque. The mesiodistal centering controls rotation, and the long axis of the bracket controls angulation. In straight-wire, the course places the bracket at the FA point (the middle of the facial axis of the clinical crown), and it notes that the bracket height tables published for MBT are more gingival on the upper incisors and canines, about 4.5 to 5 mm. Mixing a prescription with the height table of another changes the result you planned.

How to choose

There is no prescription that suits every case. Some criteria, rather than a verdict:

• Learn one system well. The studies above suggest that the clinician matters more than the prescription. Changing systems often costs more than it gains.
• Read the case before the chart. Proclined incisors, a Class II camouflage or a Class III compensation each call for a decision on torque, which may mean a different bracket on some teeth, an inverted bracket or torque in the wire (Thickett et al., 2007). Our Class II division 2 guide shows a case where torque drives the plan.
• Think about anchorage. More anterior tip means more anchorage demand during leveling.
• Use the bracket height table that belongs to the system, or the FA point, and check each bracket in two views.
• Expect to individualize. Preformed wires and average values need adjustment in finishing, whichever prescription you use.

Usage varies by setting. In a UK survey of specialists, clinicians with less than 10 years of experience used more MBT, and those with more than 20 years more Roth (Banks et al., 2010). In an online survey of orthodontists (85.2% response), MBT was the most used prescription (51.7%), followed by Roth (41.1%) (Abid et al., 2021).

In practice: a checklist

1. Know the three orders: in-out, tip and torque, and which one you are trying to change.
2. Get the manufacturer’s specification sheet for the exact values of your brackets; do not rely on a generic chart.
3. Use the bracket height table of the same system, or the FA point, and check each bracket in labial and occlusal views.
4. Plan anchorage before leveling, especially with high anterior tip in a crowded or extraction case.
5. Remember slot play: torque is expressed only with a wire that nearly fills the slot.
6. Decide the target incisor inclination from the cephalometric and clinical plan, then choose how to reach it: bracket, inverted bracket or wire torque.
7. Expect to individualize in finishing, whatever the prescription.

Frequently asked questions

What is the main difference between MBT and Roth?

MBT has less tip on the anterior teeth than Roth, and its upper incisor brackets produced a larger labial crown torque moment in a bench study. Roth favored overcorrection. In the studies that compared finished cases, these differences did not produce clinically relevant differences in final tooth position or esthetics.

Is MBT better than Roth?

No study has shown that one gives clearly better results. One small trial found less anchorage loss with MBT, one split-mouth trial found slightly faster canine retraction with MBT, and one simulation study found Roth smiles rated slightly better. Finished cases graded by experts or by an objective scoring system show little or no clinical difference.

Where can I find an MBT or Roth prescription chart?

From the manufacturer of the brackets you use. We do not reproduce per-tooth values here because we could not verify them in our course materials or in the abstracts we read, and because commercial products sold under the same name differ significantly from the standard values.

Does the slot size matter more than the prescription?

For torque, often yes. In a 0.022-inch slot, the play of a 0.019 × 0.025-inch steel wire means that part of the built-in torque is never expressed, and the difference between two prescriptions can be smaller than that play. Torque is expressed fully only with a wire that nearly fills the slot.

Can I mix Roth and MBT brackets?

Clinicians sometimes use a different bracket on selected teeth to change torque or tip, and the literature describes modifying bracket position for individual needs. What you should not mix without thinking is the bracket height table of one system with the brackets of another, because height changes both the vertical position and the torque.

With GS Ortho

GS Ortho does not choose brackets for you. What it does is help you build the diagnosis that the choice of torque depends on: the guided diagnostic studio takes each case through 12 panels, from the clinical examination and photographs to cephalometrics and the treatment plan of the same patient. AI places 29 landmarks on the lateral cephalogram for you to check and correct before the Steiner and Tweed analyses are validated, so the incisor targets are on screen when you plan. If a torque decision makes you hesitate, "Request an opinion" sends the question, with the panel attached, to a colleague or supervisor you choose; the answer stays in the record. Our free cephalometric analysis tool needs no sign-up. The GS Ortho interface is currently available in French.

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