A non-growing patient with a Class II malocclusion is in your chair. Surgery is not on the table, either because the skeletal discrepancy does not demand it or because the patient has declined it. You will treat this case in one phase, compensating. The question is where the planning starts.
In the cases students send me for review, it almost always starts with the teeth. That is the habit I spend the most time correcting. Orthodontic success rests on diagnosis and treatment planning, executed through biomechanics, and the way to cut treatment time and avoid expensive mistakes is to recognize the problem before applying the mechanics.
For one-phase compensatory Class II treatment, the evaluation sequence is fixed: facial analysis, then smile analysis, then occlusal analysis, then cephalometric analysis. Face first, teeth last. This is the protocol I teach in the DTP System, and it is the same one I follow on every Class II in my own clinic.
Step 1: Facial Analysis
The face comes first because the face is what the treatment has to serve. You cannot establish a proper treatment plan from plaster models or intraoral photos alone; they show you what the teeth are doing and say nothing about why.
I evaluate facial symmetry, facial convexity in profile, and the Lower Anterior Face Height (LAFH).
The first decision is the origin of the Class II. Maxillary protrusion, mandibular deficiency, or a combination of the two? The answer determines which arch you correct and how aggressively. A Class II driven by a deficient mandible asks for a different plan than one driven by a protruded maxilla, even when the molar relationship looks identical on the models.
Then LAFH, which sets the vertical rules for everything that follows. If LAFH is decreased, the plan will likely include extrusion of posterior teeth to rotate the mandible downward and backward, increasing face height and improving lip posture. If the patient is hyperdivergent, with increased LAFH, extrusive mechanics are strictly avoided — and that includes certain Class II elastics. Note it now. The decision comes back in Step 5, when you choose your mechanics.
Step 2: Smile Analysis
After the resting face, evaluate the dynamic smile from a frontal view. The resting face gave you the skeletal frame; the smile shows you what the patient actually presents to the world.
Check the upper and lower midlines, the symmetry of the canine positions, the buccal corridors, the smile arc, and the gingival display.
Each finding converts into a planning decision. A deviated upper midline calls for unilateral distalization. Excessively wide buccal corridors with lingually inclined posterior teeth call for dental expansion. A negative display of the upper incisors means planning anterior extrusion, while a gummy smile means planning maxillary impaction using TADs.
None of these decisions can be read from the occlusion, which is why the smile is analyzed before the teeth.
Step 3: Occlusal Analysis
Only after understanding the face and the smile do you look at the teeth. By now you know what the correction needs to accomplish; the occlusal exam tells you how much room you have to do it.
I measure the magnitude of the sagittal error, the Curve of Spee, and the overbite and overjet. Magnitude drives the extraction decision.
In a 1/3 Class II (approximately 2.5 to 3mm), extraction is rarely needed. The usual decision is to split the correction using Class II elastics, moving the upper arch back and the lower arch forward.
In a 1/2 Class II, extraction of upper premolars becomes a viable option, because reciprocal space closure speeds the treatment. Elastics or distalizers can still do the work here.
The full-step Class II, 7 to 8mm, is the most difficult to treat without surgery. The decision typically involves extracting maxillary premolars or executing full-arch maxillary distalization with absolute anchorage from TADs or IZCs.
Then the Curve of Spee. A deep curve is a hallmark of Class II cases, and flattening it requires arch length — which means the lower incisors will procline. The question to settle now is whether the patient's bone can handle that proclination. If it cannot, plan interproximal reduction or extractions from the start, instead of discovering the limit mid-treatment.
Step 4: Cephalometric Analysis
The ceph comes last, and the position is deliberate. Cephalometrics confirm what the clinical examination already showed; they do not dictate the plan. I repeat this to my students constantly, because the temptation to plan toward rigid numerical norms is strong, and a plan built to satisfy an average measurement rarely fits the face you examined in Step 1.
From the tracing I want McNamara's Triangle, the maxilla/mandible/LAFH ratio, and the anatomical limits of the mandibular symphysis.
The symphysis is the measurement I most often find missing when students send me their planning. Assess the actual bone thickness. If the symphysis is extremely thin, which is common in hyperdivergent profiles, avoid any mechanics that procline the lower incisors, however convenient that proclination would be for flattening the Curve of Spee. Pivot to extractions and stay inside the biological boundaries the bone gives you.
Step 5: The Execution Sequence
With the diagnosis written, the biomechanics follow a strict order: transverse first, vertical second, sagittal third.
In practice, this means the vertical is corrected before any sagittal retraction begins. You cannot retract anterior teeth while a deep bite keeps the upper and lower incisors in physical contact. Open the bite early, often using cantilevers or posterior bite turbos on the first molars, to flatten the Curve of Spee and create the horizontal clearance the retraction will need.
If extractions made it into the plan, choose the sites with the profile in mind. In a Class II with mandibular deficiency, avoid extracting lower premolars. Doing so forces the retraction of the lower canines, which then requires massive retraction of the upper arch to match, and that flattens the patient's profile, the opposite of what a deficient mandible needs. Opt for upper premolar extractions or a single lower incisor extraction instead.
And the elastics. Class II elastics go in only after the overbite is controlled. Remember their side effects: they extrude the upper anterior and the lower posterior teeth. That makes them an appropriate choice in horizontal patterns, where increasing the vertical dimension is desirable, and a poor choice in vertical growers, the same patients you flagged in Step 1 when you measured LAFH.
Why Class II Cases Run Long
When a compensatory Class II case runs long, the instinct is to blame bracket selection or the wire sequence. Usually the problem sits further upstream. The evaluation ran in the wrong order, the plan tried to solve a sagittal problem before the vertical was stable, and the case stalled at the retraction stage behind an overbite that should have been opened months earlier.
Evaluate the face first and execute the transverse and vertical corrections before the sagittal one, and the mechanics become predictable. Cases finish faster because the barriers came out before they could cost you time.
For your next Class II consultation, a simple exercise: open the facial photographs before the models, run the four analyses in the order described here, and write the plan down, including the mechanics you ruled out and why. Keep that note in the chart. When you review the case mid-treatment, it will tell you whether the mechanics are still following the diagnosis.