- **Tooth groups:** Adjacent selected teeth show an empty circle between them — click to connect / filled to disconnect; Shift+range selects only (empty circles; overlap absorbs as singles; midline OK). Plain click select/deselect (deselect splits bridges). Never 1-tooth connected. `toothSelectionGroups.ts`; prune lab `toothProsthesis` on change. Cases/Tasks merge by prosthesis type after send.
- **Lab dispatch UI:** due date end-aligned beside title (`sm:flex-row` + `justify-between`; stacks on mobile). Prosthesis type: stacked below `md`, 50/50 same-row from `md`. Content clinical field = **Notes** (not case comments).
- **Lab comments:** shared `LabCaseCommentsPanel` (newest-first; sent=`justify-start`, received=`justify-end`; `viewerSide`) across Treatment / Cases / Tasks / share. Use logical `text-start`/`text-end`, not left/right.
- **Detail chrome:** chips + Add at top; **Remove** = trash on chip (unsent, >1 detail; disabled when day-locked / no edit / uploading). No delete in Content step.
- **History filters (client-side):** `PastTreatmentsPanel` — “Not shipped to lab” + single date; helpers in `treatmentHistoryFilters.ts`.
- **Lab shipment block:** lab-dependent detail with no teeth saves but cannot ship — `LabShipmentBlockedNotice`, inline banner, toast on add shipment.
- **Edit gating:** `canEditTreatmentForDay` = permission + appointment + not past day + `live` mode. Sent detail locks that line; Add still OK same day. Upload rejects sent (`TREATMENT_DETAIL_SENT`).
- **Lab search:** `LinkedOrganizationSearchCombobox`; invite lab via `/organizations?action=invite-lab` when permitted.