MESA

Labeling an arch

One arch at a time, already numbered by the model. What follows is how this tool behaves — where it is reliable, where it is not, and what it cannot do at all.

How to number a tooth

The model numbers crowns by counting outward from the midline, so an absent tooth shifts every number behind it in that quadrant. It has no way to detect the gap.

the panel

Tooth number

tooth 7

14 teeth · 3 renumbered

Click a tooth	Selects it. Its number appears in the box and the crown goes to full colour. The selected tooth is always the most saturated thing on the arch and never the palest, because pale is what enamel belonging to no tooth looks like — a highlight that washed a crown out once read as the label having been lost.
Type two digits, `Enter`	Sets the number.
Empty the box, `Enter`	Clears it. The tooth shows ? until somebody answers it.

A code this arch cannot carry is refused with the reason, rather than accepted quietly.

animation

How to read the arch

Every number is drawn on the crown it belongs to. The colour is this tool's state, never a clinical reading.

16	Numbered.
?	No number on it yet.
34	Shares a number with another crown.
26	Flagged.

How to use the chart

The row of codes in Tooth number is the whole arch at a glance.

16	A tooth carries this number. Click it to select that tooth.
17	Nobody has accounted for it. Click it if the tooth is not in the mouth.
24	Marked absent. Click again to undo.
34	Two teeth claim it. Saving is blocked until you fix it.

animation

An unmarked position is ambiguous: extracted, not reached yet, outside the scan, and missed by the model all look the same from here. Marking it absent says which.

Fill enclosed enamel paints enamel. Pick a tooth and press it — there is nothing to arm first. It dims for one reason only, which is that no tooth is picked, and it says so rather than looking armed and swallowing your clicks.

How to paint a surface

The Tooth pane. Pick a type, then drag on the arch. Each button carries the colour it paints, and the arch recolours as you go.

At the edge of a painted region the colour fades rather than stops, and the line is the border. The arch is coloured one vertex at a time, so a vertex sitting on a margin tints every triangle around it and the paint runs about a fifth of a millimetre past where the tooth really ends — which at high zoom reads as a saw blade. Fading that last ring leaves the traced line as the only hard edge. Nothing about the labels moves: the fade is on screen only, and what you save is identical either way.

animation

the panel

Tooth

Gingiva	Gum. Painting it also takes that surface away from whatever tooth held it, because gum belongs to no tooth.
Bracket / attachment	Anything bonded to a tooth — a bracket, a button, an aligner attachment. Nothing in the pipeline detects these, so every one on an arch was put there by hand.
Other / foreign body	Everything on the scan that is neither tissue nor appliance: a fragment of metal, plastic or bone, food caught round a bracket, soft buildup, hardened calculus, a film of saliva, a slice of cheek.
Enamel	Tooth surface. It goes to whichever tooth is picked in Tooth Number above, so the button is greyed until one is. This is how a crown the model cut short gets its full outline, and how the boundary between two teeth is moved — pick 26, then paint over the strip that 25 wrongly holds.
Start a new tooth	Outline a crown the model never found, or got completely wrong. Click round its edge: each click drops a pin and a straight line joins it to the last one. Click the first pin again, or press `Enter`, to close it. Everything inside becomes that tooth's enamel, even where it was coloured as gum, and the outline is an ordinary line: drag its pins, Finalize it. Then type its number. `Backspace` takes the last pin back, `Esc` cancels, and `⌘Z` removes the whole tooth. If the outline does not close tight, it says so and fills nothing.

One stroke sets both halves. Painting Enamel says this surface is tooth and that it belongs to whichever tooth is picked. Painting Gingiva says it is gum and belongs to nothing. Enamel on no tooth is not a state this tool can be left in — while the two could be set apart, a saved arch could call one patch of surface gum and tooth 26 at the same time.

Fill enclosed enamel	Paints a whole region at once instead of dragging across it. Pick the surface type first — Fill paints the armed answer, so choose Gingiva, or a tooth for enamel — then click inside a region and everything the lines enclose takes it. It stops at the lines and nowhere else, so a region the lines do not close is not a region: a fill started in it runs out across the arch until it meets something. If a gap is what you have, close it first by DRAWING a short line across it: a new line's ends snap to whatever they land near. Dragging an existing end does not snap any more — it stays exactly where you put it. Against the model's own segmentation, a fill lands on the tooth at a median overlap of 0.956. Click near a line rather than inside a region and it fills the region on one side of it — which side is not worth guessing at, so aim for the middle. `⌘Z` puts the whole fill back. The lines bound the fill, and nothing else does. Everything inside a closed ring becomes that tooth — whatever colour it was wearing, and whatever the model called it. That is how a blotch of the neighbour's colour in the middle of a crown gets cleared, and how the specks a scan marks as gum across the neck of a tooth get filled in. On one real arch a single upper central carried 444 of those. The paint goes right up to the line: the margin itself is handed to whichever side lies on. Each line knows exactly where it crosses each triangle, so the points under it go to the side they are actually on — the paint reaches the line, stops at it, and never crosses it. That also settles the points a line completely covers, which no amount of filling could reach before: a small patch of gum left inside a finished tooth is almost always one of those. So is a scrap the lines seal off from the rest of the crown — where a line touches itself, or two of them cross, or one clips a cusp — leaving a piece of surface the fill could not walk to from where you clicked. On one traced arch that was an island of gum 1.7 mm across sitting inside an upper second molar, and nothing in the tool could reach it. A scrap counts as inside only when the wall around it opens onto this tooth and onto nothing else: touching one region makes it a hole, touching two makes it a seam. Zoom in as far as you like and the edge between two teeth stays a hard edge — each pixel takes the colour of the nearest labelled point rather than a blend of the three around it, so a boundary is never smeared across the 0.2 mm triangle it runs through. The scan's own triangles are cut along the line to make that true. The few that cannot be — about one in sixty, where a line crosses three sides of the same triangle — keep one colour across the whole triangle, which is the faint sawtooth you can still find if you go looking for it. If the ring does not close, nothing is painted. The fill says which two teeth are open to each other and marks in red every place they touch with no line between them — on one real arch, 842 such places between the two upper centrals over about 4 mm. How fast you drew a line makes no difference to whether it holds — a line is a solid fence at any drawing speed. Draw the boundary between the two crowns end to end, then fill again. Marks out in the middle of the neighbour's crown are not a mistake: that is where the model gave this tooth's colour to a patch of the neighbour, and the line along the seam puts them back on the right side of it. The same happens when a fill runs out over the gum. A tooth whose outline is open anywhere — most often the last molar, whose back margin the tracer leaves in pieces — takes the gum with it, so nothing is painted and every open stretch of its outline is marked in red. On one real arch the upper right second molar had 320 such points in 40 separate openings, the widest about 3.7 mm. The ring defines the tooth. Whatever the lines enclose becomes that tooth, and whatever wears that tooth's colour outside the ring stops being it and goes back to gingiva. That second half is what stops a crown leaving a trail of its own colour smeared over the gum and its neighbours — on one real arch a tooth had 745 such points against 4,604 inside its own ring, and no click inside could reach them. So: enclose it, fill it, and the tooth is defined. One click takes what the ring holds. Specks of that tooth stranded outside it — inside the gum, or inside a neighbour — are not reachable from where you clicked and belong to Tidy the whole arch, which takes a tooth's colour off everything outside its own ring. It will not merge two teeth. On some arches the line between two neighbours is drawn but does not close a ring round either of them, and the fill — which stops at walls, not at what a line says it divides — would then claim both crowns and stamp one tooth over the pair. When that is what a click would do, the fill refuses and names the other tooth instead. Move the line between them, or if the two really are one fused crown, flag it. A rim of a neighbour is still taken: that is the fill working, and it is what the button is for.
Tidy the whole arch	This runs by itself when an arch opens, so most of the time you will never press it. What it is for is a tooth it had to leave alone — close that outline, then press it to finish the job. It does not run on an arch somebody has already worked on: a saved file is a person's judgement and the sweep would overwrite it. It puts every tooth inside its own lines in one press, and takes that tooth's colour off everything outside them. A fill does this for the one tooth you click; this does it for all of them, which is how a stray speck somewhere you are not looking gets cleared. A tooth it cannot do is named and left completely alone rather than half done. `⌘Z` puts the whole sweep back. It also puts every point on its own side of the line. Not just the band the line runs through: any point labelled as enamel or as gum is settled against the region the lines carve around it. On one arch's own model labels that is 631 enamel points sitting outside the tooth they are numbered as, 319 gum points inside a crown, and 128 given to the wrong tooth. Tidy says how many it moved. A finding is never moved, and never hidden. A tooth's margin says where its enamel ends and the gum begins — that is all it says. Artifact, bracket, calculus and food debris are patches of surface that sit where they sit, on a crown or on the gum, and no margin contains one. Neither the sweep nor the colour touches them. What you see stops at a line. So does what is saved, once Tidy has run. On screen, enamel and gum are painted by the region the lines carve, so that colour boundary can only fall where a line actually runs. The file still holds whatever the label says until the sweep settles it, so an arch that looks finished has not been corrected until it has been swept. It also says when a crown does not measure like the tooth it is numbered as. Each one's area is compared against measured 10th-percentile crown areas for that position — real populations of 79 to 271 teeth — and a crown under half of it is reported as a fragment rather than a whole tooth. It only says so; nothing is deleted or repainted on it. Those figures are permanent teeth only, so a primary tooth given a permanent number will measure small and be perfectly correct, and the message says as much. It is silent until the teeth are numbered, because it cannot judge a crown that has not been told what it is. It tells you which fault a skipped tooth has, because the two need opposite answers. Its outline is open means a gap in the ring — often a single point wide — and a fill poured in runs straight out into the gum. Close it by drawing a short line across the gap, whose ends snap to what they land near. Dragging an existing end will not close it for you: a dragged end stays where it is released, so the two have to actually meet. Filling it would swallow 34 is the opposite — the ring is closed, but it encloses the neighbour too, so the line between the two is missing rather than broken. Hunting for a gap on that one wastes the time, which is why it is worth saying which is which.
Copy diagnostics	Puts what the tool is currently looking at on the clipboard: the arch, how many lines are live, how the surface is labelled, which tooth is selected — as both its instance number and its FDI number — and what the last fill decided, including how big the patch was and how many gaps it found. Paste it into a message when something does not behave. It is the same state the tool already has; the value is that it comes from your session rather than from somebody reconstructing it from a screenshot.

To stop painting, click the lit button again — or press Esc. With nothing lit, a click on the arch picks a tooth rather than painting, and that is how you choose which tooth Enamel will go to. While a type is armed its name sits over the arch — with the tooth number beside it, for enamel — because painting without realising it is how a neighbouring crown gets relabelled by accident.

Four answers, not eight. Foreign body, food debris, materia alba and calculus were once four separate buttons and are now all Other / foreign body: the distinction was finer than the job needs, and choosing between eight slowed the work down. The model marks these regions before you see the arch — it cannot tell them apart either — so the job is confirming what it already found rather than hunting for it. Arches labelled under the old eight keep exactly the labels they were given.

The Vector Line Tool

The outlines drawn over the arch are the boundaries between one surface and the next — a tooth and the gum, or two teeth meeting. They are traced from the model's own segmentation and smoothed, so they arrive already following the arch rather than waiting to be drawn from nothing.

One thing is removed on the way: a hook, where the line dives off the crown and comes straight back along itself. That is the segmentation's own ragged edge, not a margin, and the line is closed across the mouth of it instead. It is cut only while it stays as narrow as it starts — a line going around something, at a contact or a bracket, is left exactly where the segmentation put it. Nothing else about the line moves, and no point is ever invented: what you see is where the boundary is.

the panel

Vector Line Tool

Change surface view

Handles	The points you can grab on a line when you adjust it. There is nothing to set. A line is given at most eight, placed where it bends rather than every so many millimetres, and they are re-counted from the line itself every time — so joining two lines, or moving one, gives you the right handles back without asking. Short lines come back with fewer: handles are never placed closer than 0.3 mm apart, so a 2 mm line gets two or three whatever the ceiling is.
Tooth outlines	One closed line per tooth, derived from that tooth's own colour, with 14 to 20 pins, as few as keep the line within 0.4 mm of the colour's edge — so they gather where the outline bends, and Finalize EVO pulls the line onto the edge from there — and straight lines between them until you finalize it. Finalize EVO for Arch turns every one into a smooth curve on the enamel edge. This is what an arch is made of — there is one kind of line and nothing to switch to. A drag cannot reach a line you did not grab. Each outline is a closed ring of its own, sharing nothing with its neighbours, so moving a pin on one tooth leaves every other tooth exactly where it was. The tool used to also offer a traced network, whose curves met at shared points — there, dragging the point between the two front teeth moved both of their lines. That is gone. It is worked out when the arch opens, which takes about a fifth of a second. Painting afterwards does not move the lines; they are the label as it was when you opened it. At a contact the two teeth's lines sit side by side. Every line is drawn just inside its own tooth, so where two crowns touch you see two lines next to each other, each in its own tooth's colour, meeting exactly at the border. The border itself is where the two lines touch, and that is where the colour stops. They are independent: drag a pin on one and only that tooth's line moves. Hover just inside a tooth to get its line. At a contact the line you get is the one drawn on the side you are pointing at, so point at the line you can see. Away from a contact it makes no difference: the nearest line still wins. A finalized line has no nodes and is never the one you get, so it cannot hide a neighbour's nodes where that neighbour's line runs into it. A tooth whose colour is in several separate pieces, or which has holes in it, gets a line round each piece and each hole that borders more than a few stray points — often a tiny loop where two teeth touch and the scan has a gap — so you will see some small loops. That is the label underneath, drawn honestly rather than hidden, and it is what keeps each tooth its own colour. A tooth at the edge of the scan gets a line that runs from edge to edge rather than round. One thing to know: letting go of a pin refits the line through the surface, so a dropped pin can settle up to 0.1 mm from the line drawn through it.
Flat Shaded Clay	The Change surface view pane. How the arch itself is drawn, which is a different question from how the lines are, and its own section for that reason. Flat is the arch as it is labelled. Shaded, the default, keeps those colours and folds in the surface's own relief, so a fissure, an interproximal col and the bulge of a crown read as shape rather than as flat colour. Clay drops the labels for a neutral grey and leaves nothing but the form. Clay is the one for deciding where a tooth actually ends: with the label colours gone they cannot steer the judgement. That is also why it is not a view to paint in — you cannot see what is marked. Honestly stated, because it matters for what you expect: this does not outline a gum line the way it outlines a fissure. A margin is often not a groove at all on these scans — the gum sweeps onto the tooth smoothly. What the shading gives you is the form around the margin, enough to judge whether a line sits where the tooth really ends. The drawn line is still the strongest thing on screen. Nothing about the labels changes; it is a lens.
Adjust a line	Pick it and the lines brighten and thicken. Hover a tooth's line and its white pins appear, 14 to 20 round each tooth. Press one and drag: the pin goes where you put it and the two straight lines either side of it swing with it, like a rubber band held at the next pin on each side. Nothing else on the line moves. The two lines are laid exactly the way every untouched line is, so picking a pin up and putting it straight back changes nothing. Let go and it is done; `⌘Z` puts the line and its pins back as they were. What a drag reaches is the whole of what it changes, and it was not always. A drag used to rebuild the line from its handles, and eight handles cannot carry a 33 mm gum margin: rebuilding one without moving anything shifted it by up to 0.9 mm along its entire length. Because dragging a joint moves every line meeting it, nudging a contact between two teeth could re-shape a margin 30 mm away — reported as “drag one side and some weird cone comes out the other”. Nothing is rebuilt now; the points are moved where they are. Every line wears the colour of the tooth it defines, so the line around the red crown is red. A line between two crowns is drawn in the colour of the crown on its left — one colour, not two. It used to alternate between both, because the side a line recorded was arbitrary and picking one would have named a crown at random; the side is now measured from the curve's own direction and is right on 99% of them. On a typical arch about one line in six runs between two teeth, and those were drawn as roughly 150 short alternating runs. Each line keeps a dark casing under its colour, because a red line drawn on a red crown would otherwise be invisible. The handles sit where the line bends, not every so many millimetres: a wave's tip gets one, and a straight run gets few, because a straight run needs no holding. Measured over 135 sharp features on one arch, a handle lands within 0.1 mm of the tip 99 times against 54 for even spacing. How many you get depends on how long the line is — six at most, and never two closer than 0.3 mm, because a handle you cannot aim at separately is not a handle. Measured: a 10 mm tooth margin gets the full six; a 1.9 mm line gets four; a stub under half a millimetre gets its two ends and nothing between. On a 10 mm margin that is a handle every 2 mm or so, so small nudges are what this is for. Pull one handle a whole millimetre and you will get a point at it, because that is what moving one handle that far means — move its neighbours too and the line stays smooth. Handles are only a way to hold the line: what gets saved is the same dense boundary the model reads, and a line you never touch keeps the tracer's own points exactly. The first and last handles are not just points on the line — they are the joints where it meets its neighbours, and on one arch every single line has at least one. Drag a joint and every line meeting there follows it, so the network never comes apart; the message says how many moved, and `⌘Z` puts all of them back at once. Let a joint go next to another one and the two become a single joint. Between two teeth that touch, a joint is often several joints a fifth of a millimetre apart. Where the crowns interlock, the scan's labels flip back and forth between the two crowns meeting and a sliver of gum between them, so the boundary there is three borders braided together rather than one line — which is why that stretch comes back as a row of short dashes rather than a single curve. You do not have to take them one at a time: grab one of the short dashes and the whole braid moves, keeping its shape, and the message will say eight lines moved rather than three. Grab a crown's own border there and only that border moves, along with the lines that actually meet the joint you took hold of. The braid used to come with it, which dragged the neighbouring crown's border bodily — its end sits on a different joint a fifth of a millimetre away. Measured over every line-end on one arch: 34 grabs moved a border that does not meet the handle, and none do now. The short dashes between the two joints stretch instead.
Draw a new line	The same as Start a new tooth: click pins round a crown, straight lines between them, and close it into that tooth's outline.
Erase a line	Click a line to remove it, or drag a box to remove several at once — segmentation leaves a lot of short spurious boundaries, and taking them one at a time is the slow way. While you drag, every line the box will take turns red, and the message says how many; let go and they go. `⌘Z` puts the whole boxful back in one press, `Esc` abandons a box you are still drawing, and nothing is lost until you save. Two rules make the box safe to swing about. It takes a line when more than half of it is inside — one merely clipped at the edge is left alone, so a box over a stub cannot swallow the long margin running past it, but the line you actually surrounded does go. And it takes only lines you can actually see: one on the far side of the arch is left alone however squarely the box sits over it on screen, while one lying on a flank that curves away from you still goes, because you can see it. The second rule used to ask which way the surface tilted instead, which is a different question — from a close view that refused 34 of one arch's 111 lines, and a short one in plain sight among them.

Lines are saved with the arch, and ⌘Z takes a drag back. A whole drag undoes as one step, in the same order as everything else you have done — the last thing you did is the thing that comes back, whether it was a fill or a line. Save and Finalize behave exactly as they do for painting, and an arch with a moved line counts as unsaved work until you save it.

A line that divides nothing is not drawn. Paint a stray speck of tooth out of the gum and the little ring that was drawn around it goes with it, because there is now the same thing on both sides of it. The model leaves a few of these on every arch — eight on a recent one — and they are conspicuous out of proportion to their size, since a line is the same few pixels wide however far you zoom out.

It is hidden, not erased. Put the speck back and the line comes back, and what you save carries every line the model traced either way.

A line with no length is not drawn either. A curve that begins and ends in the same place, a fraction of the width of one triangle, was never a line — but it was drawn at the full width of the band, so it showed up as a solid dot sitting on a crown. The smoothing step that made them was corrected on 30 September and the archive re-traced, which took them from one curve in nine to one in three thousand. The tool still declines to draw one, for the arches not yet re-traced and for the stray click that leaves one behind. They are hidden on the same terms as the rest: still in the file, still holding the fill in exactly the place they always did.

The colours follow the line. Let go of a handle and each side of the line is filled with what it already was, up to where you just put it — so the yellow ends at the line and the gum starts there. The message says how many points followed, and ⌘Z takes the move and the fill back together.

It only ever repaints the two things that line divides. A bracket, an artifact or any finding inside the same region is left exactly as it is: on one arch the gum region alone holds 10,616 vertices of artifact, and a fill that took the whole region would erase every one of them.

Two columns

The left column is what you mark the arch with — the tooth number, the surface type, the lines. The right column is the session: which arch you are on, how you are looking at it, and saving. Nothing in either column should need scrolling on a normal screen; if it does, the window is unusually short.

View

The right button turns the arch and the wheel zooms it, and that is the fast way to move. But while a tool is armed the left button belongs to the tool, so reaching a surface on the far side means letting go of what you were doing. The four sliders do the same job without letting go, and they read the camera back — turn the arch with the mouse and they follow it.

X, Y and Z are the arch's own axes, the same ones the rest of the pipeline uses: X runs to the patient's left, Y forward to the front teeth, and Z up through the biting surfaces. Z is exact — spinning the arch runs about that axis and no other. X and Y are close rather than exact: X is your height above the arch, which is a turn about the patient-left axis only while Z is at 0, and Y twists about whatever you are currently looking along.

the panel

View

Turn the arch without letting go of the tool

X72° Y0° Z0° Zoom100%

X	Raises and lowers your eye. 90° would be straight down onto the biting surfaces and 0° is edge on at gum level, so the buccal and lingual walls are the low numbers. It stops just short of 90 on purpose: directly over the arch there is no direction left for Z to turn in.
Y	Twists the picture, the way you would turn a photograph. It does not move the arch or your eye — only which way is up on screen. Useful for laying a quadrant along the screen before working down it.
Z	Spins the arch like a disk on the table. 0° faces the front teeth; the number runs round to the patient's left.
Zoom	A percentage of the view the arch opens at, so 200% is twice as close on any arch whatever its size. It runs from 25% out to 20000%, which puts about half a millimetre across the screen — two or three of the scan's own triangles, which is where you check whether a margin follows the surface or the triangulation. The track is not linear: each step along it multiplies rather than adds, so the ordinary range near 100% gets the same room to move in as the far end. The wheel stops at the same place the slider does; it used to carry on past it.
Reset the view	Back to the framing the arch opened with. Worth knowing where this is before you use Roll: a tilted arch has no landmark that tells you which way is level.

None of this moves the arch itself. The sliders move the camera, so nothing you have painted or drawn changes, and the coordinates the model reads stay exactly as they were.

What the tool tells you

Two things are said over the arch, one above the other, because that is where you are looking while you work rather than at a panel in the corner. The pale pill is the tool that is armed. Below it, in red, is what just happened — 2 lines erased — ⌘Z puts them back, took surface from tooth 26, already gingiva here. It disappears when there is nothing to say.

Undo, and the flag

How to take something back, and what to do with a shape no number can describe.

There is no brush. Nothing on this arch is ever painted by dragging across it. The only thing that colours anything in is Fill enclosed enamel, and it will only do it when the lines close the enamel completely. That is the whole of it: draw the lines until a tooth is enclosed, press the button, and the tooth is defined.

Undo	Takes back the last thing you did, whether that was a fill, a line moved, a line drawn or a line erased. A fill counts as one action however much it coloured — a click that moved four thousand points comes back in one press, not four thousand.
Redo	Puts back what Undo just took. It lives in the right-click menu. Doing anything new after an undo clears it, because the change you undid no longer fits the arch in front of you.
Flag	For a shape no number fits: two crowns fused into one, or a fragment that is not a whole tooth. Flagging lets the arch be saved while that shape is still unnumbered, and records that a person decided it rather than missed it. It is not for an untidy edge — an untidy edge is a line in the wrong place, so move the line.

Filling a surface the colour it already is does nothing at all, and says so. The counter beside the chart is the only honest sign that something changed.

How to choose an arch

Every arch in the archive is listed under Arches, at the top of the right-hand column, with a filled dot beside the ones already labeled and a count at the top. Click one to open it. If you have unsaved work the browser asks before it leaves.

The list is in three bands. Arches you have started and not finished come first, with an amber dot — so work left half done is at the top rather than wherever its name falls among several hundred. Finished arches follow, blue for finalized and green for approved. Arches nobody has opened come last. The order is set when the page loads, so saving does not shuffle rows out from under you.

The list is deliberately short — a few rows, not two hundred. Type in find an arch to narrow it: any part of the name works, so p07 finds that patient's visits and lower finds every lower scan. The count changes to say how many you are looking at, and clearing the box brings the rest back.

animation

the panel

Arches 14/194

How to move the view

While a tool is armed the left button belongs to the tool, so the camera moves on the right button: right-drag turns the arch, shift and right-drag slides it sideways, the middle button slides it too, and the wheel zooms whatever is armed. With no tool armed the left button turns it and the right slides it.

Drag sideways to spin it like a turntable, up and down to tip it, scroll to zoom. A tooth's number disappears when the arch hides it, rather than floating over whichever crown is in front.

While a paint tool is live the left button is painting, so right-drag turns the arch instead. You can follow a boundary round a crown without putting the tool down.

animation

The right-click menu

Right-click on the arch and a small menu opens where you clicked. Press Esc, or click anywhere else, to close it without choosing anything.

Add adjustment pin	Right-click on a line, where you want a pin. One appears there and stays there. Use it where a crown has a feature the line is cutting across — a notch, a groove between two cusps — because the pins a line starts with are spread evenly and cannot know where those are.
Remove adjustment pin	Right-click on a pin. It goes, and the line runs straight from the pin before it to the pin after it, so any bend that pin was holding goes too. One `⌘Z` brings back the pin and the bend. The two pins at the ends of a line stay: an end is where two lines join, and one you cannot grab is one you cannot join. Rarely — where the scan folds over itself, or on the thin biting edge of a front tooth — a straight line would let the tooth's colour leak out; then the pin stays and the message says so. Drag it instead.
Finalize EVO for Arch	Right-click anywhere on the arch once every tooth's nodes are where you want them. The algorithm makes one pass over every tooth at once and turns each outline (its Enamel Vector Outline) from straight lines into a smooth curve on the enamel edge — the dark line Shaded view draws — with no nodes, in the tooth's own colour like every line and node. Each tooth is worked out against its neighbours' lines as you left them, so where two teeth meet their lines stay side by side. A tooth whose colour would leak out keeps its nodes and the message says so. One `⌘Z` undoes the whole arch.
Unfinalize EVO for Arch	Right-click anywhere on the arch. Every finalized tooth gets its nodes back exactly as you left them, and can be adjusted again.
Unfinalize EVO for this tooth	Right-click on one finalized tooth — its line or its enamel. The menu names the tooth, and only that one gets its nodes back; the rest stay finalized. One `⌘Z` undoes it. Finalize EVO for Arch afterwards finalizes just the teeth that are back on nodes.
Undo / Redo	The same two commands as the Undo button, at the pointer. Adding and removing pins is undone like anything else.

Right-click, not right-drag. Dragging with the right button still turns the arch, exactly as it did. The menu only opens if you press and release without moving, so looking around never puts a menu over the tooth you are working on.

Keyboard shortcuts

`Enter`	Apply the number in the box.
`Esc`	Closes the right-click menu if one is open. Otherwise stop painting and return to Pick a tooth. Clicking the live tool again does the same.
`⌘Z` / `Ctrl Z`	Undo the last stroke.

How to save

Save writes the whole arch — every tooth's number, what each surface is, which positions you marked absent, and which regions you flagged. Press it as often as you like; it records where the work got to.

Finalize writes the same thing and says you are done with this arch. That is the difference the archive counts: an arch you saved and left half done is In progress, not finished.

Approve appears on an arch somebody has already finalized. It is the sign-off, and it records who gave it and when. The tool checks nothing about you beyond your sign-in, so treat it as the doctor's button.

Not started	Nobody has saved this arch.
In progress	Saved, not yet finished.
Ready for final review	Finalized by whoever labelled it, waiting on the doctor.
Approved	Signed off after review. Nothing further is needed.
Archive	For an arch with fixed braces, which the client asked us not to work on. It leaves the labelling list for the Archived — braces heading at the bottom, and it cannot be saved or finalized while archived; any work already saved on it is kept. Anyone signed in can archive. On an archived arch the same button reads Restore and puts it back.

Nothing forces an order. An arch can go back to In progress at any point — saving one that had been finalized or approved does exactly that, because the work has changed since somebody said it was done. And arches can be taken in any order: there is no queue to work through front to back.

Save and Finalize stay disabled while two teeth share a number, because that is the one mistake nobody can spot later.

The dot beside an arch in the Arches list carries the same four states, and so do the marks on the front page: amber is in progress, blue is ready for final review, green is approved, and a grey mark is one nobody has opened.