I've reindexed the sentences.

Splitting out がく.

@@ -35,5 +34,0 @@
-</r_ele>
-<r_ele>
-<reb>がく</reb>
-<re_restr>顎</re_restr>
-<re_restr>腭</re_restr>

Google N-gram Corpus Counts
╭─ー─┬───────────┬───────╮
│ 顎 │ 1.313.492 │ 99.2% │
│ 頤 │     7.008 │  0.5% │
│ 腮 │     2.073 │  0.2% │
│ 顋 │       914 │  0.1% │
│ 齶 │       129 │  0.0% │
│ 腭 │         0 │  0.0% │
╰─ー─┴───────────┴───────╯
No initial match for 腭
腭 is a 簡体字 of 齶
However, there are 35 results on yourei: https://yourei.jp/腭
It is in sankoku, oukoku, daijs, nikkoku and daijr
And I see no indication for it being [oK], so I'm changing it to [rK]

It doesn't seem like 齶 is [oK] either, it's very rare and not in my refs so I'm hiding it.
When I search for 齶 in mdict I get sent to 腭 anyway

顋 is not in my refs while it does still possess the reading あご. Also not a 旧字体. Hiding it as well
Jitenon says it is sometimes treated as a 簡体字 of 腮 and vice versa.

腮 is not in my refs either but again possesses the あご reading. Hiding it.

頤 is in most refs, but looking at the ngrams it is [rK]. The third edition of meikyo has it in () and GendaiSK doesn't have it anymore.


Having がく here as a reading is maybe a bit questionable. Super daijr has 【顎・鄂・腭】, daijr has 【顎・腭】and the other refs have either just 顎 or an affix entry.
Also the only gloss I see for it is: 動物の口の器官の一部。あご。
.

Overhaul

@@ -11,0 +12,5 @@
+<ke_inf>&rK;</ke_inf>
+</k_ele>
+<k_ele>
+<keb>腭</keb>
+<ke_inf>&rK;</ke_inf>
@@ -15 +20 @@
-<ke_inf>&oK;</ke_inf>
+<ke_inf>&sK;</ke_inf>
@@ -19 +24 @@
-<ke_inf>&oK;</ke_inf>
+<ke_inf>&sK;</ke_inf>
@@ -23,5 +28 @@
-<ke_inf>&oK;</ke_inf>
-</k_ele>
-<k_ele>
-<keb>腭</keb>
-<ke_inf>&oK;</ke_inf>
+<ke_inf>&sK;</ke_inf>