Hi.
Welcome to HEALTHCARE MAGIC..
I have gone through your query and can understand your concerns..
As per your complain and explanation of the symptoms the bump in the location you described seems to be a superficial salivary duct stone in the duct of the sub mandibular
salivary gland,and if it is over the jaw bone it can be a minute
bony exostosis..
One more cause of the bump can be a
mucocele [mucous cyst] although it is not so small as of size of pen tip but can also be possible..
You need not to worry and consult an Oral Physician and get evaluated and in case of salivary gland stone if it is superficial and is so easily palpable the
dentist can remove it simply by pushing it gently towards the duct opening and in case if it does not get removed then a surgical removal can be done by an incision on mucosa in the region near the stone..
In case of bony exostosis removal depends upon the discomfort, in case if it is causing discomfort surgical or
laser removal can be done otherwise it can be left as it is as it is not fatal..
For small mucoceles no treatment is commonly required as they resolve themselves, concentrated salt water rinses can be helpful..
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Thanks and regards..
Dr.Honey Nandwani Arora..