Rehabilitation of a Patient with Severely Resorbed Mandibular Residual Ridge Using Neutral Zone Technique:

A CASE REPORT

Presented By

Dr. Anjana Maharjan

NAMS 1st Year Resident

Introduction

• Many edentulous patient present with severely resorbed mandibular ridge

• Loose and unstable lower complete denture is one of most common problem faced

• Neutral zone technique – over come problem

Due to long term edentulsim and wearing of ill fitting dentures

Neutral zone

Based upon concept that for each individual patient, there exists within denture space specific area where function of musculature will not unseat denture and where forces generated by tongue are neutralized by forces generated by lips and cheeks

Potential space between lips and cheeks on one side and tongue on other; that area or position where forces between tongue and cheeks or lips are equal(GPT-8)

Neutral zone

Severely Atrophic

Mandibular Ridge

Prominent and Highly Attached Mentalis

↓Neuromuscular Control Atypical

shape of Oral

Structures

INDICATION

Advantages

Good AestheticsImproved Masticatory

Performance

Improved Stability, Retention Support

Case Report

A 68 year old male patient reported to department of prosthodontics, NAMS with chief complaint of unstable mandibular denture

Medical history of Hypertension and under medication

Intra oral view

Procedure

Primary Impressions

Special Tray Fabricated

Border Moulding with

Green Stick

Wax record rims constructed and jaw relation done

Lower occlusal rim removed and substituted with acrylic pillars

8

Adapted to Lower record base

Neutral zone impression material- mixing • 2 parts of high fusing impression compound• 1 parts of low fusing impression compound

• Instruct patient to perform functional movements – swallowing – sucking – Pronounce exaggerated

EEE and OOO soundsDo not use maxillary record base during clinical registration of mandibular neutral zone impression to avoid compressive interference ,if occlusal contacts are encountered

Remove the base from water bath and quickly place intra orally and instruct patient to perform functional movements like swallowing , sucking and ask to pronounce exaggerated EEE and OOO sound. When neutral zone record had cooled and hardened ,remove and inspect the accuracy and completeness .(this procedure was repeated from 3-4 times until the record is satisfactory

Impression material is then removed and replaced by wax; the use of the index will make sure that wax replicates neutral zone record.

Subsequently, teeth should be set and flanges contoured according to index that represents NZ

Laboratory Procedure

Try In Done

External impression

External impression of neutral zone made with medium body polyvinylsiloxane Wax from facial aspect of maxillary denture were remove and applied impression material

Upper Buccal AspectInstruct patient -• Pucker lip forward , smile broadly • Open mouth wide • Move mandible from side to side

Lower Buccal Aspect

Instruct patient• Pucker lips forward • Smile broadly• Move mandible from side to

side

Lower Lingual Aspect

Instruct patient • Sip water and swallow • Extend tongue• Move from side to side • Lick upper and lower lips

Insertion of Denture

Outcome

• Increased stability and retention of mandibular denture

• Patient was fully satisfied with function and esthetics

• Even in recall visit - after 24 hrs and after 1week , patient had no complaint and was very comfortable.

Conclusion

• Simple technique.

• In highly resorbed mandibular ridge, this technique can be an alternative for construction of lower complete dentures

Technique is relatively simple but there are increased chair time and laboratory costs

Acknowledgement

Prof. Dr. Sarita Joshi

Coordinator, Prosthodontics

NAMS, Bir Hospital

Asst. Prof .Dr . Dipak Thapa

Asst . Prof. Dr. Pramod Raj Joshi

Residents of NAMS