Evaluation of residual ridge and restorative space for diagnosing and determining implant placement options for overdentures in completely edentulous patients

Abstract

INTRODUCTION: Rehabilitation of completely edentulous patients has taken a major improvisation with the introduction of implants in complete denture treatment. Overdentures have stood the test of time and overdentures supported by implants have sustained over the years as a viable cost efficient treatment option. Host factors like the available bone and restorative space have been the major influencers when planning and designing an implant overdenture. This study emphasises considering the ridge formalso when planning attributing to the varying stress bearing and distribution characteristics of the various ridge forms. AIM OF THE STUDY: The aim of this study is to evaluate the effect of the size and arch form of the residual ridge and restorative space on the design of final prosthesis and choice of attachment systems for overdentures in completely edentulous patients. METHODOLOGY: Sixty patients of the age group 35 to 65 years, with completely edentulous maxillary and mandibular arches with arch forms falling into either square/tapering/ovoid forms are to be selected for the study. Ethical clearance has to be obtained from the Institutional Ethical Committee. The subjects who fulfill the above mentioned criteria will be selected for the study with no discrimination based on sex, caste, religion or socioeconomic status. The complete treatment procedure will be explained to the patients and a written informed consent will be obtained from all the patients selected for the study. The arch forms and available restorative space are assessed and recorded for each patient. The sixty subjects are divided into 3 groups based on their mandibular arch forms. Group I: (n=20) square arch form, Group II: (n=20) V-shaped or tapering arch form, Group III: (n=20) ovoid arch form. The intra-oral examination is done. Using the patient’s casts the ridge form is determined. The routine steps in fabrication of complete dentures are carried out. After trial dentures are fabricated, gutta-percha markers are used to mark the incisal edges of the teeth. An Orthopantamogram of the patient with dentures in mouth is taken. The inter-foraminal distance and the vertical restorative space available for restoration are measured. The magnification errors are rectified for each patient.. The ridge dimensions are measured clinically; data are categorized as residual ridge dimensions, restorative space dimensions, proposed implant number and subjected to statistical analysis. RESULTS: The One-way ANOVA shows that Ridge width and Interforaminal distance is significantly different according to residual ridge forms. In the post hoc test (Tukey’s test), significant difference in Ridge width is found between Ovoid and Square type groups (Square type ridge width is higher significantly. In the post hoc test (Tukey’s test), significant difference in Interforaminal distance is found between Ovoid and Tapering group with Square type groups (Square type interforaminal distance is higher significantly). CONCLUSION: Within the limitations of the study done the following conclusions were drawn: o Ridge width and Interforaminal distance is significantly different according to residual ridge forms. o Significant difference in Ridge width is found between Ovoid and Square type groups (Square type ridge width is higher significantly). o Hence, according to the arch forms, the dimensions considered for treatment planning differ significantly. Further in vivo finite element analysis studies based on the arch forms in implant overdenture will help clinicians in better designing of prosthesis and choice of attachment systems