The bite stick is a specialized dental instrument used to diagnose incomplete fractures, often called Cracked Tooth Syndrome. This small device, sometimes sold as Tooth Slooth or FracFinder, applies selective pressure to individual parts of a tooth. Its primary function is to isolate a specific cusp or area to reproduce the patient’s pain, which is often vague or difficult to locate. By concentrating biting force on a tiny point, the bite stick helps confirm the presence and location of a fracture line too fine to be seen easily or detected on an X-ray.
Identifying When to Use a Bite Stick
The use of a bite stick is indicated when a patient reports sharp, momentary pain that occurs only when they chew or bite down, particularly on hard or sticky foods. This is a classic symptom of an incomplete fracture, where the tooth structure separates slightly under pressure. Patients often describe this unexplained, fleeting pain as a shock or jolt that cannot be precisely localized. The symptoms may also include hypersensitivity to cold, similar to reversible pulpitis, when a crack is suspected but not yet visible.
A bite stick is most frequently employed on posterior teeth, such as molars and premolars, especially those with extensive fillings or restorations that weaken the tooth structure. The device’s design allows for hyperspecific testing, as it is shaped to fit over a single cusp. This precision is ideal for locating a fractured cusp and is why the bite stick is preferred over less specific tools, like a cotton roll or an orange wood stick.
Detailed Technique for Using the Device
The examination begins with clear communication, informing the patient that the test may briefly reproduce their pain, which is necessary for a correct diagnosis. The tooth surface must be clean and dry for precise instrument placement. Before testing the symptomatic tooth, it is helpful to test a non-symptomatic control tooth first to establish a baseline response and build trust.
The pointed end of the bite stick is placed sequentially on each individual cusp of the suspected tooth. The patient is instructed to bite down with a controlled, moderate force, and then immediately and completely release the pressure. This bite-and-release cycle is repeated for every cusp, systematically applying concentrated pressure to the different sections of the tooth. Testing one cusp at a time allows the force to be focused along any potential fracture line originating from that specific area.
During the biting phase, the pressure causes the two segments of a cracked tooth to push together. The sudden release of this pressure allows the segments to spring apart. This separation creates a rapid, momentary fluid movement within the dentinal tubules, stimulating the pulp and causing the characteristic sharp pain. The dentist closely watches the patient’s facial expression, correlating any reaction with the specific cusp being tested.
Analyzing the Patient’s Response
Interpreting the patient’s reaction is the final and most important step in the diagnostic process. The moment the patient experiences sharp, shooting pain provides a direct clue to the nature and location of the tooth damage. Pain that occurs specifically when the pressure is released, rather than when biting down, is the classic and most telling sign of an incomplete tooth fracture. This pain-on-release phenomenon confirms the diagnosis, indicating the crack is separating when the biting force is withdrawn.
In contrast, pain elicited primarily when the patient bites down and sustained while pressure is maintained may suggest inflammation of the periodontal ligament surrounding the tooth root. The localization of the sharp pain is vital, as the specific cusp that triggers the reaction is where the crack originates. Documenting the exact location and type of pain allows for precise treatment planning, which often involves placing a crown to prevent further fracture propagation.