diff --git a/gfx/thebes/gfxDWriteFonts.cpp b/gfx/thebes/gfxDWriteFonts.cpp
index 51c086c8466..66f9cdd9cf8 100644
--- a/gfx/thebes/gfxDWriteFonts.cpp
+++ b/gfx/thebes/gfxDWriteFonts.cpp
@@ -316,8 +316,6 @@ gfxDWriteFont::ComputeMetrics(AntialiasOption anAAOption)
         fontMetrics.strikethroughPosition * mFUnitsConvFactor;
     mMetrics->strikeoutSize =
         fontMetrics.strikethroughThickness * mFUnitsConvFactor;
-    mMetrics->superscriptOffset = 0;
-    mMetrics->subscriptOffset = 0;
 
     SanitizeMetrics(mMetrics, GetFontEntry()->mIsBadUnderlineFont);
 
@@ -329,9 +327,8 @@ gfxDWriteFont::ComputeMetrics(AntialiasOption anAAOption)
     printf("    internalLeading: %f externalLeading: %f\n", mMetrics->internalLeading, mMetrics->externalLeading);
     printf("    spaceWidth: %f aveCharWidth: %f zeroOrAve: %f xHeight: %f\n",
            mMetrics->spaceWidth, mMetrics->aveCharWidth, mMetrics->zeroOrAveCharWidth, mMetrics->xHeight);
-    printf("    uOff: %f uSize: %f stOff: %f stSize: %f supOff: %f subOff: %f\n",
-           mMetrics->underlineOffset, mMetrics->underlineSize, mMetrics->strikeoutOffset, mMetrics->strikeoutSize,
-           mMetrics->superscriptOffset, mMetrics->subscriptOffset);
+    printf("    uOff: %f uSize: %f stOff: %f stSize: %f\n",
+           mMetrics->underlineOffset, mMetrics->underlineSize, mMetrics->strikeoutOffset, mMetrics->strikeoutSize);
 #endif
 }
 
diff --git a/gfx/thebes/gfxFT2FontBase.cpp b/gfx/thebes/gfxFT2FontBase.cpp
index 3755b5554bb..07c4aea861e 100644
--- a/gfx/thebes/gfxFT2FontBase.cpp
+++ b/gfx/thebes/gfxFT2FontBase.cpp
@@ -133,7 +133,7 @@ gfxFT2FontBase::GetMetrics()
     fprintf (stderr, "    maxAscent: %f maxDescent: %f\n", mMetrics.maxAscent, mMetrics.maxDescent);
     fprintf (stderr, "    internalLeading: %f externalLeading: %f\n", mMetrics.externalLeading, mMetrics.internalLeading);
     fprintf (stderr, "    spaceWidth: %f aveCharWidth: %f xHeight: %f\n", mMetrics.spaceWidth, mMetrics.aveCharWidth, mMetrics.xHeight);
-    fprintf (stderr, "    uOff: %f uSize: %f stOff: %f stSize: %f suOff: %f suSize: %f\n", mMetrics.underlineOffset, mMetrics.underlineSize, mMetrics.strikeoutOffset, mMetrics.strikeoutSize, mMetrics.superscriptOffset, mMetrics.subscriptOffset);
+    fprintf (stderr, "    uOff: %f uSize: %f stOff: %f stSize: %f\n", mMetrics.underlineOffset, mMetrics.underlineSize, mMetrics.strikeoutOffset, mMetrics.strikeoutSize);
 #endif
 
     mHasMetrics = true;
diff --git a/gfx/thebes/gfxFT2Utils.cpp b/gfx/thebes/gfxFT2Utils.cpp
index b2aace4f92b..cd202fa6cd4 100644
--- a/gfx/thebes/gfxFT2Utils.cpp
+++ b/gfx/thebes/gfxFT2Utils.cpp
@@ -67,8 +67,6 @@ gfxFT2LockedFace::GetMetrics(gfxFont::Metrics* aMetrics,
         aMetrics->zeroOrAveCharWidth = spaceWidth;
         const gfxFloat xHeight = 0.5 * emHeight;
         aMetrics->xHeight = xHeight;
-        aMetrics->superscriptOffset = xHeight;
-        aMetrics->subscriptOffset = xHeight;
         const gfxFloat underlineSize = emHeight / 14.0;
         aMetrics->underlineSize = underlineSize;
         aMetrics->underlineOffset = -underlineSize;
@@ -243,24 +241,6 @@ gfxFT2LockedFace::GetMetrics(gfxFont::Metrics* aMetrics,
     }
     SnapLineToPixels(aMetrics->strikeoutOffset, aMetrics->strikeoutSize);
 
-    if (os2 && os2->ySuperscriptYOffset) {
-        gfxFloat val = ScaleRoundDesignUnits(os2->ySuperscriptYOffset,
-                                             ftMetrics.y_scale);
-        aMetrics->superscriptOffset = std::max(1.0, val);
-    } else {
-        aMetrics->superscriptOffset = aMetrics->xHeight;
-    }
-    
-    if (os2 && os2->ySubscriptYOffset) {
-        gfxFloat val = ScaleRoundDesignUnits(os2->ySubscriptYOffset,
-                                             ftMetrics.y_scale);
-        // some fonts have the incorrect sign. 
-        val = fabs(val);
-        aMetrics->subscriptOffset = std::max(1.0, val);
-    } else {
-        aMetrics->subscriptOffset = aMetrics->xHeight;
-    }
-
     aMetrics->maxHeight = aMetrics->maxAscent + aMetrics->maxDescent;
 
     // Make the line height an integer number of pixels so that lines will be
diff --git a/gfx/thebes/gfxFont.cpp b/gfx/thebes/gfxFont.cpp
index 4a584d1b86e..77d7c923b9f 100644
--- a/gfx/thebes/gfxFont.cpp
+++ b/gfx/thebes/gfxFont.cpp
@@ -4597,8 +4597,6 @@ gfxFont::InitMetricsFromSfntTables(Metrics& aMetrics)
         // this should always be present in any valid OS/2 of any version
         if (len >= offsetof(OS2Table, sTypoLineGap) + sizeof(int16_t)) {
             SET_SIGNED(aveCharWidth, os2->xAvgCharWidth);
-            SET_SIGNED(subscriptOffset, os2->ySubscriptYOffset);
-            SET_SIGNED(superscriptOffset, os2->ySuperscriptYOffset);
             SET_SIGNED(strikeoutSize, os2->yStrikeoutSize);
             SET_SIGNED(strikeoutOffset, os2->yStrikeoutPosition);
 
@@ -4660,13 +4658,6 @@ void gfxFont::CalculateDerivedMetrics(Metrics& aMetrics)
         aMetrics.maxAdvance = aMetrics.aveCharWidth;
     }
 
-    if (!aMetrics.subscriptOffset) {
-        aMetrics.subscriptOffset = aMetrics.xHeight;
-    }
-    if (!aMetrics.superscriptOffset) {
-        aMetrics.superscriptOffset = aMetrics.xHeight;
-    }
-
     if (!aMetrics.strikeoutOffset) {
         aMetrics.strikeoutOffset = aMetrics.xHeight * 0.5;
     }
@@ -4685,19 +4676,6 @@ gfxFont::SanitizeMetrics(gfxFont::Metrics *aMetrics, bool aIsBadUnderlineFont)
         return;
     }
 
-    // MS (P)Gothic and MS (P)Mincho are not having suitable values in their super script offset.
-    // If the values are not suitable, we should use x-height instead of them.
-    // See https://bugzilla.mozilla.org/show_bug.cgi?id=353632
-    if (aMetrics->superscriptOffset <= 0 ||
-        aMetrics->superscriptOffset >= aMetrics->maxAscent) {
-        aMetrics->superscriptOffset = aMetrics->xHeight;
-    }
-    // And also checking the case of sub script offset. The old gfx for win has checked this too.
-    if (aMetrics->subscriptOffset <= 0 ||
-        aMetrics->subscriptOffset >= aMetrics->maxAscent) {
-        aMetrics->subscriptOffset = aMetrics->xHeight;
-    }
-
     aMetrics->underlineSize = std::max(1.0, aMetrics->underlineSize);
     aMetrics->strikeoutSize = std::max(1.0, aMetrics->strikeoutSize);
 
diff --git a/gfx/thebes/gfxFont.h b/gfx/thebes/gfxFont.h
index 60c688e6f05..2138f2f857b 100644
--- a/gfx/thebes/gfxFont.h
+++ b/gfx/thebes/gfxFont.h
@@ -1658,8 +1658,6 @@ public:
     // Font metrics
     struct Metrics {
         gfxFloat xHeight;
-        gfxFloat superscriptOffset;
-        gfxFloat subscriptOffset;
         gfxFloat strikeoutSize;
         gfxFloat strikeoutOffset;
         gfxFloat underlineSize;
diff --git a/gfx/thebes/gfxGDIFont.cpp b/gfx/thebes/gfxGDIFont.cpp
index 63ac41d91eb..e5aedc9dcac 100644
--- a/gfx/thebes/gfxGDIFont.cpp
+++ b/gfx/thebes/gfxGDIFont.cpp
@@ -247,9 +247,6 @@ gfxGDIFont::Initialize()
         TEXTMETRIC& metrics = oMetrics.otmTextMetrics;
 
         if (0 < GetOutlineTextMetrics(dc.GetDC(), sizeof(oMetrics), &oMetrics)) {
-            mMetrics->superscriptOffset = (double)oMetrics.otmptSuperscriptOffset.y;
-            // Some fonts have wrong sign on their subscript offset, bug 410917.
-            mMetrics->subscriptOffset = fabs((double)oMetrics.otmptSubscriptOffset.y);
             mMetrics->strikeoutSize = (double)oMetrics.otmsStrikeoutSize;
             mMetrics->strikeoutOffset = (double)oMetrics.otmsStrikeoutPosition;
             mMetrics->underlineSize = (double)oMetrics.otmsUnderscoreSize;
@@ -288,8 +285,6 @@ gfxGDIFont::Initialize()
 
             mMetrics->xHeight =
                 ROUND((float)metrics.tmAscent * DEFAULT_XHEIGHT_FACTOR);
-            mMetrics->superscriptOffset = mMetrics->xHeight;
-            mMetrics->subscriptOffset = mMetrics->xHeight;
             mMetrics->strikeoutSize = 1;
             mMetrics->strikeoutOffset = ROUND(mMetrics->xHeight * 0.5f); // 50% of xHeight
             mMetrics->underlineSize = 1;
@@ -394,9 +389,8 @@ gfxGDIFont::Initialize()
     printf("    maxAscent: %f maxDescent: %f maxAdvance: %f\n", mMetrics->maxAscent, mMetrics->maxDescent, mMetrics->maxAdvance);
     printf("    internalLeading: %f externalLeading: %f\n", mMetrics->internalLeading, mMetrics->externalLeading);
     printf("    spaceWidth: %f aveCharWidth: %f xHeight: %f\n", mMetrics->spaceWidth, mMetrics->aveCharWidth, mMetrics->xHeight);
-    printf("    uOff: %f uSize: %f stOff: %f stSize: %f supOff: %f subOff: %f\n",
-           mMetrics->underlineOffset, mMetrics->underlineSize, mMetrics->strikeoutOffset, mMetrics->strikeoutSize,
-           mMetrics->superscriptOffset, mMetrics->subscriptOffset);
+    printf("    uOff: %f uSize: %f stOff: %f stSize: %f\n",
+           mMetrics->underlineOffset, mMetrics->underlineSize, mMetrics->strikeoutOffset, mMetrics->strikeoutSize);
 #endif
 }
 
diff --git a/gfx/thebes/gfxMacFont.cpp b/gfx/thebes/gfxMacFont.cpp
index 4c1a1571a11..bf70a5637c1 100644
--- a/gfx/thebes/gfxMacFont.cpp
+++ b/gfx/thebes/gfxMacFont.cpp
@@ -332,7 +332,7 @@ gfxMacFont::InitMetrics()
     fprintf (stderr, "    maxAscent: %f maxDescent: %f maxAdvance: %f\n", mMetrics.maxAscent, mMetrics.maxDescent, mMetrics.maxAdvance);
     fprintf (stderr, "    internalLeading: %f externalLeading: %f\n", mMetrics.internalLeading, mMetrics.externalLeading);
     fprintf (stderr, "    spaceWidth: %f aveCharWidth: %f xHeight: %f\n", mMetrics.spaceWidth, mMetrics.aveCharWidth, mMetrics.xHeight);
-    fprintf (stderr, "    uOff: %f uSize: %f stOff: %f stSize: %f supOff: %f subOff: %f\n", mMetrics.underlineOffset, mMetrics.underlineSize, mMetrics.strikeoutOffset, mMetrics.strikeoutSize, mMetrics.superscriptOffset, mMetrics.subscriptOffset);
+    fprintf (stderr, "    uOff: %f uSize: %f stOff: %f stSize: %f\n", mMetrics.underlineOffset, mMetrics.underlineSize, mMetrics.strikeoutOffset, mMetrics.strikeoutSize);
 #endif
 }