Impression making is not only important but is also the most significant step in the fabrication of any fixed or removable prosthesis. Proper impression making may be hindered by certain pathologic conditions. Reduced mouth opening is one of the common mechanical obstructions for proper orientation of the impression tray in the patient’s mouth. In patients with trismus induced by submucous fibrosis, the procedure may be even more difficult to carry out because of reduced tissue resiliency and obliteration of vestibular spaces. Use of sectional trays offers one of the alternatives to overcome the problem of restricted mouth opening. Fabrication of customized impression trays according to the patient dentition improves the accuracy of impression making. The present case reports describe the fabrication of sectional custom trays designed for dentulous patients with chronic tobacco-induced submucous fibrosis.
Reduced mouth opening poses a challenge and is often a daunting task for the operator to perform any intraoral procedures. Reportedly, this problem has been associated commonly with orofacial cancer surgeries, scleroderma, traumatic injuries, temporomandibular joint disorders, oral submucous fibrosis, and so forth. One of the most commonly observed pathologies associated with limited mouth opening is oral submucous fibrosis. Rajendran, in 1994 [
45-year-old male patient and 31-year-old female patient, who were suffering from chronic oral sub mucous fibrosis, were reported to the department of prosthodontics (Sri Sai college of dental surgery, India) with a chief complaint of a missing teeth. On oral examination, maximum mouth opening was reported to be 2 cm and 2.4 cm, respectively, between incisal edges of maxillary and mandibular anteriors (Figure
Maximum mouth openings.
Because of restricted size of oral orifice and severe intraoral fibrous bands, preliminary impressions were made with polyvinyl siloxane putty material. Flexible impression tray technique described by Whitsitt and Battle [
Fabrication technique for the sectional tray—Design 1.
Fabrication technique for the sectional tray—Design 2.
After completion of the special tray fabrication, the first segment was used to make the first section of the impression. Wax spacer was removed, and the tray was loaded with polyvinyl siloxane, and sectional impression was made. Sectional impression was removed, and the excess material flown on to the lock region and the screw hole was removed. The impression was placed back in the patient’s mouth. The second part of the tray was loaded with the same impression material and oriented onto the first segment.
In the first case report, after proper orientation of the tray, a screw was used to secure the segments together before the material set. The screw helped in securing the orientation of the sections of the tray properly within the patient’s mouth. After the material had beenset, the screw was removed, and the sections were removed separately. Both the sections were approximated and secured using the screw after removal from the mouth (Figure
Impression making using the sectional tray Design 1.
In the second case report, the sections of the tray were oriented making sure that the male part of the button was seated properly onto the female part. After the material had been set, both the sections were separated and removed from mouth. Both the sections of the tray were joined together with the help of the locking button (Figure
Impression making using the sectional tray Design 2.
Impression making in patients that planned for fixed or removable partial denture with restricted mouth opening is a challenging task as it requires more accuracy and precision. The present case reports described simplified locking designs of the tray segments which could be used for both dentulous and edentulous patients for fabrication of custom trays.
In case report I, the patient was planned to receive a fixed partial denture replacing missing mandibular incisors. Patient in case report II was planned to receive a flexible removable partial denture to replace multiple missing teeth. Recording abutment finish line along with the remaining teeth is important for fabricating fixed partial denture. Similarly for fabrication of removable partial denture, the teeth along with functional depth of the sulcus have to be recorded. Practical difficulties of reduced mouth opening were overcome by designing sectional custom tray which provided an alternative for making an accurate impression.
Simple and economic sectional tray design was fallowed in the present case reports. Male and female segments of the tray were oriented by the locking mechanism which was designed using acrylic trimmer. Use of screws and press buttons helped in securing tray segments more accurately together with precession. Many techniques were described in the literature for impression making in dentulous and edentulous patients with limited mouth opening. Various mechanisms like hinges [
Simple alterations in procedural techniques help to overcome clinical difficulties faced during prosthetic management of patients with oral sub mucous fibrosis. Present case reports facilitated the operator to obtain accurate impressions for patients with limited mouth opening. These simple and logical sectional tray designs are easy to fabricate, consume less time, and require inexpensive locking mechanisms.
The authors declare that they have no conflict of interests.