diff --git a/backend/src/modules/voice/tooth-intent.resolver.spec.ts b/backend/src/modules/voice/tooth-intent.resolver.spec.ts
new file mode 100644
index 0000000..b9cd7cf
--- /dev/null
+++ b/backend/src/modules/voice/tooth-intent.resolver.spec.ts
@@ -0,0 +1,169 @@
+import {
+  resolveToothIntent,
+  resolveToothIntents,
+} from './tooth-intent.resolver';
+import type { ToothIntent } from './voice.types';
+
+const positional = (
+  arch: 'upper' | 'lower',
+  side: 'patient_right' | 'patient_left',
+  position: number,
+  spoken = 'x',
+): ToothIntent => ({ kind: 'positional', arch, side, position, spoken });
+
+const explicit = (fdi: string, spoken = 'x'): ToothIntent => ({
+  kind: 'explicit',
+  fdi,
+  spoken,
+});
+
+describe('resolveToothIntent', () => {
+  describe('positional intents', () => {
+    // "شش بالا راست" — upper right six — must be 16, not 26. A mirrored quadrant is a
+    // valid code for the wrong tooth and reaches the lab unnoticed.
+    it('resolves each quadrant from the patient perspective', () => {
+      expect(resolveToothIntent(positional('upper', 'patient_right', 6))).toBe(
+        '16',
+      );
+      expect(resolveToothIntent(positional('upper', 'patient_left', 6))).toBe(
+        '26',
+      );
+      expect(resolveToothIntent(positional('lower', 'patient_left', 6))).toBe(
+        '36',
+      );
+      expect(resolveToothIntent(positional('lower', 'patient_right', 6))).toBe(
+        '46',
+      );
+    });
+
+    it('returns null for an out-of-range position instead of clamping', () => {
+      expect(
+        resolveToothIntent(positional('upper', 'patient_right', 9)),
+      ).toBeNull();
+      expect(
+        resolveToothIntent(positional('upper', 'patient_right', 0)),
+      ).toBeNull();
+    });
+
+    it('returns null for a malformed arch or side', () => {
+      expect(
+        resolveToothIntent(
+          positional('sideways' as 'upper', 'patient_right', 6),
+        ),
+      ).toBeNull();
+      expect(
+        resolveToothIntent(
+          positional('upper', 'viewer_right' as 'patient_right', 6),
+        ),
+      ).toBeNull();
+    });
+  });
+
+  describe('explicit intents', () => {
+    it('accepts a permanent FDI code', () => {
+      expect(resolveToothIntent(explicit('14'))).toBe('14');
+      expect(resolveToothIntent(explicit('48'))).toBe('48');
+    });
+
+    it('rejects deciduous codes rather than snapping to a permanent tooth', () => {
+      expect(resolveToothIntent(explicit('51'))).toBeNull();
+      expect(resolveToothIntent(explicit('85'))).toBeNull();
+    });
+
+    it('rejects nonsense', () => {
+      for (const value of ['', '1', '99', '140']) {
+        expect(resolveToothIntent(explicit(value))).toBeNull();
+      }
+    });
+  });
+
+  it('returns null for a missing or unknown intent shape', () => {
+    expect(resolveToothIntent(undefined as unknown as ToothIntent)).toBeNull();
+    expect(
+      resolveToothIntent({ kind: 'guess' } as unknown as ToothIntent),
+    ).toBeNull();
+  });
+});
+
+describe('resolveToothIntents', () => {
+  it('resolves a mixed list and sorts the result', () => {
+    const result = resolveToothIntents([
+      positional('upper', 'patient_right', 5, 'پنج بالا راست'),
+      explicit('14', 'یک چهار'),
+    ]);
+    expect(result.teeth).toEqual(['14', '15']);
+    expect(result.unresolved).toEqual([]);
+  });
+
+  it('collapses a tooth named twice', () => {
+    const result = resolveToothIntents([
+      explicit('14', 'چهارده'),
+      positional('upper', 'patient_right', 4, 'چهار بالا راست'),
+    ]);
+    expect(result.teeth).toEqual(['14']);
+  });
+
+  it('reports what it could not understand instead of dropping it', () => {
+    const result = resolveToothIntents([
+      explicit('14', 'یک چهار'),
+      explicit('51', 'دندان شیری'),
+      positional('upper', 'patient_right', 9, 'نه بالا راست'),
+    ]);
+    expect(result.teeth).toEqual(['14']);
+    expect(result.unresolved).toEqual([
+      { spoken: 'دندان شیری', reason: 'not_permanent_tooth' },
+      { spoken: 'نه بالا راست', reason: 'position_out_of_range' },
+    ]);
+  });
+
+  it('does not repeat an identical unresolved item', () => {
+    const result = resolveToothIntents([
+      explicit('51', 'شیری'),
+      explicit('51', 'شیری'),
+    ]);
+    expect(result.unresolved).toHaveLength(1);
+  });
+
+  it('survives a non-array where the model should have sent a list', () => {
+    // The model can return an object or a number here; that must degrade, not 500.
+    for (const bad of [undefined, null, 5, 'teeth', { fdi: '14' }]) {
+      expect(resolveToothIntents(bad as unknown as ToothIntent[])).toEqual({
+        teeth: [],
+        unresolved: [],
+      });
+    }
+  });
+
+  it('trims an explicit code, matching normalizeTeeth', () => {
+    expect(resolveToothIntents([explicit(' 14 ', 'x')]).teeth).toEqual(['14']);
+  });
+
+  it('distinguishes a deciduous tooth from nonsense in the reason it reports', () => {
+    // '51' really is a (primary) tooth the chart cannot show; '99' is not a tooth at all.
+    expect(
+      resolveToothIntents([explicit('51', 'shiri')]).unresolved[0].reason,
+    ).toBe('not_permanent_tooth');
+    for (const junk of ['99', '19', '140', '', 'ab']) {
+      expect(
+        resolveToothIntents([explicit(junk, `j-${junk}`)]).unresolved[0].reason,
+      ).toBe('malformed');
+    }
+  });
+
+  it('keeps unresolved items separate when the model omits the spoken span', () => {
+    // Without `spoken` these are indistinguishable; collapsing them would hide a lost tooth.
+    const result = resolveToothIntents([
+      { kind: 'explicit', fdi: '51' } as ToothIntent,
+      { kind: 'explicit', fdi: '52' } as ToothIntent,
+    ]);
+    expect(result.unresolved).toHaveLength(2);
+  });
+
+  it('handles an empty or missing list', () => {
+    expect(resolveToothIntents([])).toEqual({ teeth: [], unresolved: [] });
+    expect(resolveToothIntents(undefined as unknown as ToothIntent[])).toEqual({
+      teeth: [],
+      unresolved: [],
+    });
+  });
+});
diff --git a/backend/src/modules/voice/tooth-intent.resolver.ts b/backend/src/modules/voice/tooth-intent.resolver.ts
new file mode 100644
index 0000000..a0f8225
--- /dev/null
+++ b/backend/src/modules/voice/tooth-intent.resolver.ts
@@ -0,0 +1,108 @@
+import { isFdiTooth, toFdi } from '../../common/fdi';
+import type { ToothIntent, UnresolvedItem } from './voice.types';
+
+export type ToothResolution = {
+  /** Unique FDI codes, sorted (matching normalizeTeeth's ordering). */
+  teeth: string[];
+  unresolved: UnresolvedItem[];
+};
+
+/** Everything here parses untrusted model output, so nothing may throw. */
+function normalizedFdi(intent: ToothIntent): string {
+  const raw = (intent as { fdi?: unknown }).fdi;
+  // Trimmed for parity with normalizeTeeth — '14 ' is tooth 14 through the treatment API
+  // and must not be "malformed" here.
+  return typeof raw === 'string' ? raw.trim() : '';
+}
+
+/**
+ * Resolve one spoken tooth reference to an FDI code, or null.
+ *
+ * Never guesses and never clamps: a position of 9, a deciduous tooth, or a malformed
+ * intent resolves to null so the caller can surface it as "not understood" rather than
+ * silently selecting a neighbouring tooth.
+ */
+export function resolveToothIntent(intent: ToothIntent): string | null {
+  if (!intent || typeof intent !== 'object') return null;
+
+  if (intent.kind === 'explicit') {
+    const fdi = normalizedFdi(intent);
+    return isFdiTooth(fdi) ? fdi : null;
+  }
+
+  if (intent.kind === 'positional') {
+    if (intent.arch !== 'upper' && intent.arch !== 'lower') return null;
+    if (intent.side !== 'patient_right' && intent.side !== 'patient_left')
+      return null;
+    return toFdi(intent.arch, intent.side, intent.position);
+  }
+
+  return null;
+}
+
+function unresolvedReason(intent: ToothIntent): UnresolvedItem['reason'] {
+  if (!intent || typeof intent !== 'object') return 'malformed';
+
+  if (intent.kind === 'explicit') {
+    const fdi = normalizedFdi(intent);
+    // Quadrants 1-4 are permanent and would already have resolved, so a well-formed
+    // quadrant+position reaching here is quadrant 5-8: deciduous. Anything else is noise.
+    return /^[1-8][1-8]$/.test(fdi) ? 'not_permanent_tooth' : 'malformed';
+  }
+
+  if (intent.kind === 'positional') {
+    const positionBad =
+      !Number.isInteger(intent.position) ||
+      intent.position < 1 ||
+      intent.position > 8;
+    return positionBad ? 'position_out_of_range' : 'malformed';
+  }
+
+  return 'malformed';
+}
+
+function spokenOf(intent: ToothIntent): string {
+  const spoken = (intent as { spoken?: unknown })?.spoken;
+  return typeof spoken === 'string' && spoken.trim() ? spoken.trim() : '';
+}
+
+/**
+ * Resolve a list of spoken tooth references.
+ *
+ * Duplicates collapse — a clinician may name the same tooth twice in one sentence — and
+ * anything unresolvable is reported rather than dropped, so the review sheet can show the
+ * user exactly which words were not understood.
+ */
+export function resolveToothIntents(
+  intents: readonly ToothIntent[],
+): ToothResolution {
+  const teeth = new Set<string>();
+  const unresolved: UnresolvedItem[] = [];
+  const seenUnresolved = new Set<string>();
+
+  // Not `intents ?? []`: a model may return an object or a number here, and a
+  // non-iterable must degrade like any other malformed shape rather than throw.
+  const list: readonly ToothIntent[] = Array.isArray(intents)
+    ? (intents as readonly ToothIntent[])
+    : [];
+
+  for (const intent of list) {
+    const fdi = resolveToothIntent(intent);
+    if (fdi) {
+      teeth.add(fdi);
+      continue;
+    }
+    const reason = unresolvedReason(intent);
+    const spoken = spokenOf(intent);
+    // Only dedupe items we can actually tell apart. Without `spoken`, two distinct lost
+    // references would collapse into one blank review row and a tooth would vanish.
+    if (spoken) {
+      const key = `${spoken}::${reason}`;
+      if (seenUnresolved.has(key)) continue;
+      seenUnresolved.add(key);
+    }
+    unresolved.push({ spoken, reason });
+  }
+
+  return { teeth: [...teeth].sort(), unresolved };
+}
diff --git a/backend/src/modules/voice/voice.types.ts b/backend/src/modules/voice/voice.types.ts
new file mode 100644
index 0000000..e94abda
--- /dev/null
+++ b/backend/src/modules/voice/voice.types.ts
@@ -0,0 +1,77 @@
+import type { Arch, PatientSide } from '../../common/fdi';
+
+/**
+ * What the extraction model is allowed to return.
+ *
+ * The model emits *intents*, never resolved values: no FDI codes, no ISO dates. Pure,
+ * unit-tested resolvers turn intents into domain values, so the two highest-consequence
+ * mappings — quadrant mirroring and Jalali conversion — are testable rather than hopeful.
+ */
+
+/** A single spoken tooth reference. `spoken` is the transcript span, echoed back to the user. */
+export type ToothIntent =
+  | { kind: 'explicit'; fdi: string; spoken: string }
+  | {
+      kind: 'positional';
+      arch: Arch;
+      side: PatientSide;
+      /** 1 = central incisor … 8 = third molar. */
+      position: number;
+      spoken: string;
+    };
+
+/** A spoken deadline. The model never does calendar arithmetic. */
+export type DueIntent =
+  | { kind: 'weekday'; weekday: Weekday; which: 'this' | 'next' }
+  | { kind: 'offset'; unit: 'day' | 'week' | 'month'; amount: number }
+  | { kind: 'jalali'; jy: number; jm: number; jd: number }
+  | { kind: 'gregorian'; y: number; m: number; d: number };
+
+export const WEEKDAYS = [
+  'saturday',
+  'sunday',
+  'monday',
+  'tuesday',
+  'wednesday',
+  'thursday',
+  'friday',
+] as const;
+
+export type Weekday = (typeof WEEKDAYS)[number];
+
+/** Two teeth defining an inclusive connected (bridge) span. */
+export type ConnectedSpanIntent = { from: ToothIntent; to: ToothIntent };
+
+export type ProsthesisIntent = {
+  /** Catalog code applied to every tooth unless overridden. */
+  defaultType: string | null;
+  overrides: { tooth: ToothIntent; type: string }[];
+};
+
+export type VoiceIntent = {
+  treatmentType: string | null;
+  teeth: ToothIntent[];
+  connectedSpans: ConnectedSpanIntent[];
+  comment: string | null;
+  prosthesis: ProsthesisIntent | null;
+  /** Must be one of the linked-lab ids supplied in the prompt, or null. */
+  labId: string | null;
+  /** False when the spoken name only approximately matched — the UI then requires an explicit tick. */
+  labMatchExact: boolean;
+  due: DueIntent | null;
+};
+
+/** Why a spoken item could not be turned into a domain value. Shown to the user. */
+export type UnresolvedReason =
+  | 'not_permanent_tooth'
+  | 'position_out_of_range'
+  | 'malformed'
+  | 'span_not_same_arch'
+  | 'unknown_catalog_code'
+  | 'invalid_date';
+
+export type UnresolvedItem = {
+  /** The transcript span that could not be resolved, so the user can see what was heard. */
+  spoken: string;
+  reason: UnresolvedReason;
+};