diff --git a/dental-server/image-processor.js b/dental-server/image-processor.js
index 074da32..e3ca232 100644
--- a/dental-server/image-processor.js
+++ b/dental-server/image-processor.js
@@ -104,15 +104,15 @@ class ImageProcessor {
   // MÉTODOS DE UTILIDADE
   // ================================================================
 
-  async getThumbnail(imageBuffer, width = 300, height = 300) {
+  async getThumbnail(imageBuffer, width = 500, height = 500) {
     try {
       const sharp = require('sharp');
       return await sharp(imageBuffer)
-        .resize(width, height, { 
+        .resize(width, height, {
           fit: 'inside',
-          withoutEnlargement: true 
+          withoutEnlargement: true
         })
-        .jpeg({ quality: 50, force: true })
+        .jpeg({ quality: 80, force: true })
         .toBuffer();
     } catch (error) {
       console.error('Erro ao gerar thumbnail:', error);
diff --git a/dental-server/public/app.js b/dental-server/public/app.js
index efc2e2a..bad760b 100644
--- a/dental-server/public/app.js
+++ b/dental-server/public/app.js
@@ -655,20 +655,28 @@ async function showTransformModal(imageId) {
             throw new Error('Imagem não encontrada na lista carregada.');
         }
 
+        // Painel "Preview" sempre mostra a versão atual (com transformações aplicadas)
         const imageUrl = image.filename.startsWith('http') ? image.filename : `/uploads/${image.filename}`;
-        
-        // Atribui a imagem às tags do DOM para exibição no painel
-        document.getElementById('originalImgPreview').src = imageUrl;
         document.getElementById('transformedImgPreview').src = imageUrl;
-        
-        // Check if the image has been modified (has original_image_id)
+
+        // Painel "Original": se a imagem foi transformada, busca a versão anterior ao processamento
         const btnResetImage = document.getElementById('btnResetImage');
         if (image.original_image_id) {
             btnResetImage.style.display = 'flex';
             btnResetImage.setAttribute('data-modified', 'true');
+            // Carrega a imagem-mãe (full-res, sem transformações) no painel Original
+            fetchWithAuth(`${API_URL}/images/${image.original_image_id}/file-url`)
+                .then(r => r.ok ? r.json() : null)
+                .then(data => {
+                    const origUrl = data && data.url ? data.url : imageUrl;
+                    document.getElementById('originalImgPreview').src = origUrl;
+                })
+                .catch(() => { document.getElementById('originalImgPreview').src = imageUrl; });
         } else {
             btnResetImage.style.display = 'none';
             btnResetImage.setAttribute('data-modified', 'false');
+            // Sem transformações: original = atual
+            document.getElementById('originalImgPreview').src = imageUrl;
         }
 
         document.getElementById('transformModalTitle').innerText = `${escapeHtml(image.patient_name || 'Desconhecido')} - ${formatDate(image.created_at)}`;
diff --git a/dental-server/public/style.css b/dental-server/public/style.css
index c2a0a70..f4604ff 100644
--- a/dental-server/public/style.css
+++ b/dental-server/public/style.css
@@ -97,11 +97,12 @@ body {
 }
 
 .sidebar-header {
-    padding: 0 24px 32px;
+    padding: 0 20px 16px;
     display: flex;
     align-items: center;
     gap: 12px;
     border-bottom: none;
+    flex-shrink: 0;
 }
 
 .logo-icon {
@@ -127,8 +128,8 @@ body {
 .sidebar-nav {
     display: flex;
     flex-direction: column;
-    gap: 8px;
-    padding: 0 16px;
+    gap: 2px;
+    padding: 0 12px;
     flex: 1;
     overflow-y: auto;
 }
@@ -170,8 +171,10 @@ body {
 }
 
 .sidebar-footer {
-    padding: 0 16px;
-    margin-bottom: 12px;
+    padding: 12px 16px;
+    border-top: 1px solid var(--border-color);
+    margin-top: auto;
+    flex-shrink: 0;
 }
 
 .logout-btn {
@@ -841,11 +844,7 @@ body {
     padding: 10px 16px;
 }
 
-.sidebar-footer {
-    padding: 20px;
-    border-top: 1px solid var(--border-color);
-    margin-top: auto;
-}
+/* sidebar-footer definida acima, perto do .sidebar */
 
 .sidebar-brand {
     display: flex;
diff --git a/dental-server/routes/images.js b/dental-server/routes/images.js
index 12bf28f..4980d85 100644
--- a/dental-server/routes/images.js
+++ b/dental-server/routes/images.js
@@ -456,6 +456,23 @@ router.delete('/:id', async (req, res) => {
   }
 });
 
+// ================================================================
+// GET /api/images/:id/file-url — Retorna a URL de visualização
+// full-res de uma imagem (para o painel Original do modal)
+// ================================================================
+router.get('/:id/file-url', async (req, res) => {
+  try {
+    const image = await db.get('SELECT filename FROM images WHERE id = $1', [req.params.id]);
+    if (!image) return res.status(404).json({ error: 'Imagem não encontrada' });
+    const url = image.filename.startsWith('http')
+      ? image.filename
+      : `/uploads/${image.filename}`;
+    res.json({ url });
+  } catch (e) {
+    res.status(500).json({ error: e.message });
+  }
+});
+
 // ================================================================
 // PUT /api/images/:id/toggle-enabled - Habilitar/Desabilitar
 // ================================================================
@@ -475,4 +492,51 @@ router.put('/:id/toggle-enabled', async (req, res) => {
   }
 });
 
+// ================================================================
+// POST /api/images/backfill-thumbs — Gera thumbnails para imagens
+// que ainda não têm thumb_filename. Roda em background; retorna
+// imediatamente com o total de imagens na fila.
+// ================================================================
+router.post('/backfill-thumbs', async (req, res) => {
+  try {
+    const rows = await db.all(
+      `SELECT id, filename, client_name, patient_name
+       FROM images
+       WHERE thumb_filename IS NULL AND enabled = true
+       ORDER BY created_at DESC`
+    );
+    res.json({ queued: rows.length, message: 'Backfill iniciado em background' });
+    // Processa sem bloquear a resposta
+    setImmediate(() => runThumbBackfill(rows));
+  } catch (e) {
+    res.status(500).json({ error: e.message });
+  }
+});
+
+async function runThumbBackfill(rows) {
+  const UPLOAD_DIR   = process.env.UPLOAD_DIR   || path.join(__dirname, '..', '..', 'uploads');
+  const PROCESSED_DIR = process.env.PROCESSED_DIR || path.join(__dirname, '..', '..', 'processed');
+  let done = 0, failed = 0;
+  for (const row of rows) {
+    try {
+      // Tenta carregar a imagem do disco local
+      let imgBuffer = null;
+      for (const dir of [UPLOAD_DIR, PROCESSED_DIR]) {
+        try { imgBuffer = await fs.readFile(path.join(dir, row.filename)); break; } catch (_) {}
+      }
+      if (!imgBuffer) { failed++; continue; }
+      const thumbBuffer   = await imageProcessor.getThumbnail(imgBuffer);
+      const thumbFilename = `thumb_${row.filename.replace(/\.[^.]+$/, '')}.jpg`;
+      await storage.saveImage(thumbFilename, thumbBuffer, row.client_name, row.patient_name, false);
+      await db.run('UPDATE images SET thumb_filename = $1 WHERE id = $2', [thumbFilename, row.id]);
+      done++;
+    } catch (e) {
+      failed++;
+    }
+  }
+  console.log(`[backfill-thumbs] concluído: ${done} geradas, ${failed} falhas de ${rows.length} total`);
+}
+
+// Exporta a função para ser chamada no boot do servidor
 module.exports = router;
+module.exports.runThumbBackfill = runThumbBackfill;
diff --git a/dental-server/server.js b/dental-server/server.js
index 45412ef..83694c3 100644
--- a/dental-server/server.js
+++ b/dental-server/server.js
@@ -507,6 +507,8 @@ async function serveHtmlWithCacheBuster(res, filePath) {
     // Injeta versão em tags de script e css
     content = content.replace(/src="([^"]+\.js)(?:\?v=[^"]*)?"/g, `src="$1?v=${APP_VERSION}"`);
     content = content.replace(/href="([^"]+\.css)(?:\?v=[^"]*)?"/g, `href="$1?v=${APP_VERSION}"`);
+    // Substitui o número de versão exibido na sidebar (elimina hardcode no HTML)
+    content = content.replace(/(<span[^>]*>)\s*v\d+\.\d+\.\d+\s*(<\/span>)/g, `$1v${APP_VERSION}$2`);
     
     res.set('Content-Type', 'text/html');
     res.set('Cache-Control', 'no-store, no-cache, must-revalidate, private');
@@ -1233,6 +1235,21 @@ async function start() {
     redis.initRedis();
 
     // Iniciar servidor
+    // Backfill de thumbnails ausentes: roda em background após o boot
+    setTimeout(async () => {
+      try {
+        const { runThumbBackfill } = require('./routes/images');
+        const missing = await db.all(
+          `SELECT id, filename, client_name, patient_name FROM images
+           WHERE thumb_filename IS NULL AND enabled = true ORDER BY created_at DESC`
+        );
+        if (missing.length > 0) {
+          console.log(`[boot] Iniciando backfill de thumbnails para ${missing.length} imagem(ns) sem thumb...`);
+          runThumbBackfill(missing);
+        }
+      } catch (e) { /* silencia erro de backfill para não afetar o boot */ }
+    }, 5000);
+
     server.listen(PORT, () => {
       console.log('═══════════════════════════════════════════════════════');
       console.log('🚀 DENTAL IMAGE SERVER STARTED');