I suspect this may be related to the temporomandibular joint syndrome (Costen).   Audiovestibular symptoms in TMJ disorder seem to be due to Meniere Spectrum Disorder, though why pressure changes in the inner ear should be connected with jaw movements is unclear.  So does your patient complain of pressure/blockage in ear; dizziness; audiosensitivity;  distorted hearing; tinnitus; etc?  If so, this can only be MSD.  I assume middle ear effusion has been ruled out.

It is a very rare to have such complains but you may want to refer for ENT assessment. There is a paper that looked at hearing loss and the wearing of dentures, shortened arches etc. The link is below. 

http://www.ncbi.nlm.nih.gov/pubmed/15089934

Hearing loss related to complete dentures is rare. One might think of co-occurrence of edentulousness and age related hearing loss as both of them may occur in the same age. A study conducted in 2001 found that 'for every tooth lost since baseline, there was a 1.04 times as high odds  for hearing decline'(Spec Care Dentist. 2001 Jul-Aug;21(4):129-40.). Another study has, in fact, found that absence of denture may cause hearing impairment (J Oral Rehabil. 2004 Apr;31(4):306-10.). There has also been a recent case report that shows how unilateral hearing impairment was managed by correcting TMJ dysfunction (J Am Dent Assoc. 2015 Mar;146(3):192-4. doi: 10.1016/j.adaj.2014.12.012.). TMD may be caused due to improper VD in a complete denture, hence may be a cause for hearing impairment. Additionally there is a curious case report where there was a sudden hearing loss after dental treatment (J Oral Maxillofac Surg. 2013 Aug;71(8):1318-21. doi: 10.1016/j.joms.2013.03.014. Epub 2013 May 1.). 

http://www.ncbi.nlm.nih.gov/pubmed/11669061

http://www.ncbi.nlm.nih.gov/pubmed/15089934

http://www.ncbi.nlm.nih.gov/pubmed/25726347

http://www.ncbi.nlm.nih.gov/pubmed/23642550

Is the vertical dimension of occlusion significantly reduced. If so, the countraclockwise rotation of the condyle could affect retrodiscal tissue, but it is unlikly that it affects hearing. How about Eustachies tube opening in pharinx. Maybe mucosal tissue is sore due to lingual extension of lower denture. But loss of hearinh is probably due to other reasons than denture wearing

Here is an extract from the abstract for JOMS (2013) (See link above);

A 66-year-old man presented with impaired balance, tinnitus, sensation of blockage, and hearing loss in his left ear, which developed after dental treatment for dental pain 4 days previously...Impaired balance decreased spontaneously within 3 days...The patient had improved hearing and resolution of tinnitus.

This is a "Full House" for endolymphatic hydrops.

Here is an extract from the abstract for JADA (2015), see link above: 

A 73-year-old woman had a 4-month history of debilitating left-sided otic fullness, hearing loss, and a watery sensation in her ear without obvious cause. She had consulted with an otolaryngologist who cleared the ear of all middle ear pathology and then placed ventilation tubes in the tympanic membrane to relieve her symptoms of ear fullness. The ventilation tubes did not produce long-lasting relief so she was referred to the dental clinic.

A sensation of fullness, pressure or water in the ear is pathognomonic of endolymphatic hydrops.  The ear feels blocked, but this has nothing at all to do with a blocked eustachian tube.  Abnormal jaw positions or movements could easily cause the E tube on one side to fail to close, leading to dehydration in the middle ear, reduced perilymph pressure and hence endolymphatic hydrops.  If this explains the link between TMJ syndrome and ear problems, the mediation by patent E tubes should already have been flagged up in the literature, which I have not yet checked out.

Sometimes tubes can be closed pharingealy due to pharingitis and patient feels like his hearing is worsened.  Sometimes distolingual extension of lower denture, or extensive pressure of pharingeal maxillary denture border can cause pharingitis. However, I commented that it is not likely ib the case mentioned above

Here is a website with detailed clinical descriptions of hydrops, mentioning the intense psychological distress involved, made worse by failure of doctors to recognize or diagnose the condition.  Several persons mention TMJ problems.

http://ehealthforum.com/health/partially-patulous-eustachian-tube-with-tinnitus-t197476.html

Maybe there is a tiny root tip underneath one of the dentures, left over from an old extraction attempt.  Stimulating the area of the root tip from the pressures of eating with the dentures helped awaken an active infection around the root tip.  It is common for root tip infections to cause pain in the ear.  Observe the edentulous areas using 6-8x magnification and co-axial illumination to see if there are microscopic abscess drainage pathways around old root tips.

The dentures may also allow the patient to eat a wider variety of foods.  Maybe the patient is eating a different food with the dentures, a food that causes hearing loss?  An allergic reaction to certain foods perhaps may cause hearing loss?  Consuming toxic foods like grilled meats, that the patient was not eating before the dentures but is eating now, can cause damage to the sensitive hearing nerve, by exposing the nerve to toxins or free radicals in food?

dears

Dissections of human by Pinto (1962) Komori et al. (1986) and other researchers (Rees, 1954; Coleman, 1970; Ioannides & Hoogland, 1983; Perry et al., 1985; Loughner et al., 1989; Rodríguez & Vásquez, et al., 1993; Morgan et al., 1995; Mérida-Velasco et al., 1997; Rodríguez-Velásquez, et al., 1998) proved a specific anatomical link between the TMJ, the mandibular body and the middle ear. This connection is made by the sphenomandibular ligament that attach to the malleus of the ossicular chain in its anterior process and create a biomechanical connection between the middle ear and the mandibule. (Hoshino, 1988). in the petrotympanic fissure trespassing together within the Huguier Channel. The sphenomandibular ligament is inserted in the lingula or mandibular spix spine and originates in the malleus, part of the sphenoid spine and the most medial zone of the petrotympanic fissure.

as consequence the VDO vertical dimension of occlusion, the condyle position and the occlusal scheme could have a role. Clinically the patient should be reconsidered for the TMD treatment

with a new prosthesis made after occlusal therapy

best regards,

This may be attributed to Costen's syndrome which is stated to be the result of prolonged over-closure and it consists of:

Mild catarrhal deafness and dizzy spells which can be relieved by inflation of the Eustachian tubes.

Tinnitus or snapping noise in the joint while chewing, and the affected joint may be painful, with limited or excessive movements.

Tenderness or dull pain while palpating over the affected TMJ.

Various neuralgic symptoms such as: burning or prickling sensation of the tongue, throat, or side of the nose.

Various forms of atypical head pain that refer to temporal region or base of the skull.

Dryness of mouth due to disturbed salivary gland function.

Regards,

read this mate :

http://www.ncbi.nlm.nih.gov/pubmed/15089934

http://www.ncbi.nlm.nih.gov/pubmed/19505871

"This may be attributed to Costen's syndrome which is stated to be the result of prolonged over-closure and it consists of:

Mild catarrhal deafness and dizzy spells which can be relieved by inflation of the Eustachian tubes."

What is the evidence for any conductive or middle ear deafness?