Orthodontic study models are accurate reproductions of a patient's teeth and surrounding tissues that are important diagnostic aids for orthodontists. Ideal study models accurately reproduce the dental anatomy without distortion, are trimmed symmetrically for easy identification of asymmetries, accurately reproduce occlusion when placed on their backs, and have a clean smooth surface while depicting as much of the alveolar process as possible. Study models consist of an anatomical stone plaster portion imprinted from the dental impression and an artistic plaster base that supports the anatomical portion and gives the models a pleasing symmetrical appearance.

1. ORTHODONTIC STUDY MODELS
PROF (Dr.) SAIBEL FARISHTA

2. STUDY MODELS ARE ACCURATE REPRODUCTIONS OF TEETH AND THEIR
SURROUNDING SOFT TISSUES. THEY ARE IMPORTANT DIAGNOSTIC AID IN
ORTHODONTICS AND MAKE IT POSSIBLE TO VIEW OCCLUSION FROM ALL
ASPECTS.
IDEAL REQUISITES OF ORTHODONTIC STUDY MODELS
1. THE MODELS SHOULD ACCURATELY REPRODUCE THE TEETH AND THEIR
SURROUNDING SOFT TISSUES WITHOUT DISTORTION.
2. THE MODELS ARE TO BE TRIMMED IN SUCH A MANNER THAT THEY ARE
SYMMETRICAL AND PLEASING TO THE EYE. THIS HELPS IN IDENTIFICATION
OF ASYMMETRIES.
3. WHEN THE MODELS ARE PLACED ON THEIR BACKS, THEY SHOULD
ACCURATELY REPRODUCE OCCLUSION.
4. THE MODELS SHOULD HAVE A CLEAN, SMOOTH AND NODULE FREE
SURFACE.
5. THE STUDY MODELS SHOULD NOT ONLY DEPICT THE TEETH BUT SHOULD
ALSO REPRODUCE AS MUCH OF THE ALVEOLAR PROCESS AS POSSIBLE.

3. PARTS OF A STUDY MODEL
THE ORTHODONTIC STUDY MODELS CONSIST OF 2 PARTS - ANATOMIC AND
ARTISTIC PARTS.
THE ANATOMIC PORTION IS THAT PART WHICH IS THE ACTUAL IMPRESSION
OF THE DENTAL ARCH AND IT’S SURROUNDING STRUCTURES. THIS PORTION
IS USUALLY MADE OF STONE PLASTER. THE ARTISTIC PORTION OF THE STUDY
MODEL CONSISTS OF A PLASTER BASE THAT SUPPORTS THE ANATOMIC
PORTION. THE ANATOMIC PORTION GIVES A PLEASING AND SYMMETRICAL
APPEARANCE TO THE MODELS. THE RATIO BETWEEN ANATOMIC PORTION
TO ARTISTIC PORTION SHOULD BE 3:1.
STEPS IN CONSTRUCTION OF STUDY MODELS
1. IMPRESSION MAKING
2. DISINFECTION OF THE IMPRESSION
3. CASTING THE IMPRESSION
4. BASING AND TRIMMING OF THE CAST

4. BASE FORMERS ORTHODONTIC IMPRESSION TRAYS

10. FINISHING & POLISHING

12. THANK YOU