postsurgical maxillary defects predispose the patient to hypernasal speech , liquid leakage into the nasal cavity , and impaired masticatory function . in the total rehabilitation of the maxillectomy patient , the maxillofacial prosthodontist has two primary objectives ; first to restore the functions of mastication ,   deglutition , and speech and secondly to achieve normal orofacial appearance . ideally , any anatomic defect should be surgically reconstructed . however , when surgical reconstruction is contraindicated , prosthetic reconstruction must be employed to restore anatomy , function , and esthetics . the goals of prosthetic rehabilitation for total and partial maxillectomy patients include separation of oral and nasal cavities to allow adequate deglutition and articulation , possible support of the orbital contents to prevent enophthalmos and diplopia , support of the soft tissue to restore the midfacial contour , and an acceptable aesthetic results . limited mouth opening often complicates and compromises the treatment of patients , who underwent maxillectomy due to combined effect of radiotherapy and surgical procedures done . trismus may occur due to inflammation and insults to muscles of mastication and other surrounding tissues . a method of overcoming impression difficulties that uses a custom impression tray modified with altered impression for such patients is outlined and illustrated in present case report to simplify the impression procedure to obtain a successful prosthesis . a 49-year - old male patient presented with a chief complaint of missing teeth in the upper jaw . his primary concerns were inability to chew food , difficulty in speech , and the regurgitation of the food into the nasal cavity . he had been diagnosed with mucoepidermoid carcinoma of minor salivary glands for which a bilateral partial maxillectomy was done , leaving a small portion of the premaxilla . no preprosthetic consideration was made before surgery , and this probably had worsened the case resulting in irretrievable limited mouth opening . intraoral examination revealed bilateral missing maxillary posterior teeth and teeth present in premaxilla were 11 , 21 , 22 , and 23 ( figure 1(a ) ) . a part of the soft palate which was in the continuation with hard palate was also resected , due to which functional inefficiency of soft palate was seen . obturator prosthesis with soft palatal extension was planned for covering the defect improving speech , mastication , and esthetics . oral prophylaxis was completed and a primary impression of the hard palate was made by an irreversible hydrocolloid impression material ( zelgan , dentsply india pvt ltd , india ) with modifying the stock tray in the defect region ( figure 2(a ) ) . the impression was then poured in type iii dental stone ( kalstone , kalabhai , karson pvt ltd , mumbai , india ) . a special tray was then constructed following a predetermined outline on the stone model using autopolymerizing acrylic resin ( dental products of india ltd , new delhi , india ) . the bulb portion of the hard palate was made with putty silicon impression material ( 3 m espe ag , germany ) and adhered to the custom tray . a posterior extension of medium fusing impression compound ( y - dents impression compound ; mdm corporation , new delhi , india ) was added to acrylic tray to contact the pharyngeal wall when it closes during speech and swallowing . it was confirmed that the extensions was made at the level of the hard palate and at the level of the most active movement of the pharyngeal sphincter . right and left neck movement and swallowing was performed by the patient for recording the soft palate extension . the patient was asked to perform the same movements during the final wash impression of soft palate with zinc - oxide eugenol impression paste ( dpi impression paste , dental products of india , mumbai , india ) , after scraping the impression compound about 0.5  mm ( figure 2(b ) ) . this impression was placed over the stone model of hard palate , in which the posterior landmark area was trimmed for properly joining the extended impression . now proper beading and boxing of the soft palatal extended part was performed ( figure 3(a ) ) for making the master cast by altered cast technique ( figure 3(b ) ) . jaw relation was recorded at reduced vertical height for providing better comfort to tissues and also for ease in insertion and removal of the prosthesis . teeth arrangement was done and prosthesis was finally verified esthetically and physiologically during try - in procedure . as there was restricted mouth opening , height of the bulbs was reduced for curing with heat - cured acrylic resin ( trevalon hi , dentsply india pvt ltd , india ) . the tissue surface of the bulb was then finally relined with the soft liner ( permasoft denture liner ; dentsply austenal , york pa ) ( figure 4 ) . the insertion of the obturator into the defect was possible in a rotational path ; from mediodistal to bucco - anterior . the obturator was fully seated ( figure 5 ) and confirmed that the prosthesis was easily placed and removed by the patient . the patient was satisfied with the function , esthetics , and retention of the prosthesis and greatly improved oral hygiene and maintenance were observed . bilateral complete maxillectomy is a relatively uncommon surgical procedure resulting in devastating effects on the cosmetic , functional , and psychological aspects of a patient 's life . as multiple surgeries can not be performed at this stage , prosthetic restorations have become the preferred method for the rehabilitation of complex mid - facial defects like the bilateral or unilateral maxillectomy . recently , it has been reported that obturator prosthesis function is closely related to patient quality of life . they allow rapid , single stage reconstruction which is important since improvement in the quality of life is of paramount concern as in many of these patients , surgery may be only palliative . in most of the cases , trismus is exacerbated by surgery prior to radiation and by radiation field that includes the muscles of mastication and the temporomandibular joint . in patients treated for nasopharyngeal carcinoma with radiotherapy , the maximum interincisal distance was reported to be reduced to 97% of its original distance in the first nine weeks after radiotherapy . further reduction to 73% , 69% , 68% , and 67% were observed in 12 , 24 , 36 , and 48 months , respectively .   if not managed at initial days , it will lead to life - long reduced mouth opening , difficulty in eating , and problem in performance of dental procedures . reason for reduced mouth opening in the present case report was the same , and the patient was not ready for any further surgery for improvement of fibrosis . exercise could not help the patient for improving mouth opening due to permanent scar formation . as the mouth opening was just 1.5  cm , it was not possible to record soft and hard palatal portion in a single impression so modification in the impression procedure by using altered cast impression technique with some modification was thought . advantages of the altered cast technique used in the present case report include simplified tray manipulation , decreased patient trauma , the ability to use a custom fabricated tray for optimal impression material thickness , precise intraoral positioning , and stability of the tray . clinical applications of magnetic attachments in maxillofacial prostheses have been used as overdenture abutments and for attachments between components of the prostheses [ 8 , 9 ] . magnet attachments need efficacy for adjustment of final placement of upper and lower parts of the prosthesis during insertion , and also the defect was bilateral and large which needed more complicated treatment . keeping these points in view a conventional type of obturator with posterior extension in a single piece mediolaterally the mouth width was competent enough for placement of the prosthesis after slight tilting of the prosthesis . hence reducing the height of bulbs was an effective option for prosthesis insertion and also the soft liner used was somewhat flexible for helping in placement of prosthesis . insertion and removal of large prostheses used for rehabilitation of maxillectomy requires good neuromotor coordination and an adequate mouth opening . absence of these factors in the present case report had compromised the prognosis of the treatment . to accomplish this , heights of the bulbs were reduced and to compensate for the compromised direct retention , maximum use of the lateral periphery contour of defect and scar tissue was desired . a maxillofacial prosthesis can not restore the intricate neuromuscular structure but can only be used as an alternative means for appropriate function . how successful that alternative is , will depend upon the patient 's ability to accept the defect and to adapt to an alternative environment .
patients with extensive head and neck injuries due to trauma and/or extensive surgical procedures often exhibit a severely limited ability to open the mouth . for 
 the dentist involved in prosthodontic treatment of such patients , restricted mouth opening commonly leads to compromised impressions and prostheses especially in cases where both hard and soft palatal parts have been resected . 
 in prosthodontic treatment , the loaded impression tray is the largest item requiring intraoral placement . during impression procedures , 
 wide mouth opening is required for proper tray insertion and alignment . 
 this is not possible in patients with restricted mouth opening , so a modification of the standard impression procedure is often necessary to accomplish this fundamental step in the fabrication of a successful prosthesis . 
 an alteration in the final impression procedure was made using altered cast technique for fabricating an obturator prosthesis with soft palate extension , and the result obtained was quite satisfactory .