April 05, 2020
A dentist uses a range of instruments that perform specific functions in various treatment plans. Out of the dentists' artillery, we decided to analyze two multifunctional cutting instruments: Chisel and Osteotome.
The word chisel is derived from the old French word 'cisel,' which means 'to cut.' Osteotome on the other hand is made by the combination of two Latin words 'osteo' & 'tome,' which mean 'bone' & 'cutting' respectively.
Types, design and function of osteotomes
An osteotome is most frequently used in bone shaping and contouring. It is a bi-bevelled instrument, meaning, it has two cutting edges. It is shaped like a narrow wedge and splitting of the bone is done in the direction of the blade. There are various types of osteotome designs depending on the procedure for which they are used.
• Pterygoid osteotome: It is used in orthognathic procedures in LeFort-I osteotomies. It has a long, flat and curved working blade along with a broad and circular design of the handle.
• Rhinoplasty osteotome: Specifically designed for nasal osteotomies, the length of this instrument is 18 cm. It is a fine straight instrument with rounded corners and a recessed grip. Four different types of blades of varied sizes can be used in a rhinoplasty osteotome.
• Straight osteotome: This type of osteotome is used in elevation of the floor of maxillary sinus. It is straight in design with a concave working end. Markings are present at 7mm, 10mm, 11mm, 13mm and 15mm. The instrument is available in fur different diameters.
• Offset osteotome: The offset osteotome is similar in function as that of the straight osteotome. The only difference in design is that it has a curved shank and is available in five different diameters.
Types, design and function of chisel surgical instrument
A chisel's working tip edge has a bevel on one side unlike the osteotome which is bi-bevelled. Based on width of the blade, it comes in four different sizes: 5mm, 6mm, 10mm and 15mm. It is preferably 1/4th in width and the handle is around 7 inches long. In order to smoothen the bone, the bevel is kept facing the bone whereas in order to cut it, the bevel is kept away from the bone.
• Pterygoid Chisel: It is used in LeFort-I osteotomy procedures. It is a flat instrument with a single bevel on a serrated working end.
• Nasal chisel with guard: This is a paired instrument having extensions on lateral edges that ensures safe rhinoplasty.
• Central nasal chisel: It resembles a nasal guard except that it has a small extensions arising from both edges. It is used for the osteotomy of the nasal septum.
• Straight Chisel: Straight chisel has a straight shank and blade that is used in a push motion for cutting enamel.
• Mono angle, Bi-angle, Triple angle: Depending on the number of angles, in the shank, chisels can be mono, bi or tri-angle. A bi-angle shank is used for cleaving undermined enamel whereas a tri-angle shank is used for flattening the pulpal floor.
• Wedelstaedt Chisel: A Wedelstaedt chisel is similar to straight chisel only that its shank has a slight curvature. It maybe mesially or distally bevelled and is used to shape walls on the proximal surface of anterior teeth.
• Ochsenbein Chisel: This chisel has semi-circular indentations on both sides of the shank. It allows the instrument to engage around the tooth in the interdental area.
• Reverse action/Rhode's Chisel: This type of chisel is used distal to the last molars. It is used for removing bone adjacent to the tooth and is used in a pull stroke.
• Enamel Hatchet: This mono bevelled chisel is used for smoothening the buccal and lingual walls of proximal box. It is also used for breaking the enamel of the proximal box.
• Gingival Marginal Trimmer: This is a paired, bi-angle, mono-bevelled instrument used for bevelling the axio-pulpal line angle.
• Read's/Coupland's chisel: This chisel is used in transalveolar extraction and for splitting the tooth during extraction.
• Chisel Scaler: This double ended chisel with a curved shank is used for removing tenacious subgingival deposits.
• Triangular Chisel: This chisel has a triangular shape blade with the base away from the shaft.