Functional Bite Diagnostics in Ukraine

The bite is more than the way the teeth meet in one fixed position. The lower jaw moves in three planes: it opens, moves forward and shifts to the side, while the condyles slide along the slopes of the articular eminences. The teeth guide this movement with their inclined surfaces. A routine chairside check shows only where the jaw ends up when it closes, not the path it takes to get there.

A functional examination measures this path for the individual patient and reproduces it outside the mouth. The models of the jaws are mounted in an articulator, which imitates the action of the joints; a face-bow transfers the position of the upper jaw relative to the skull; a centric relation record captures the position of the lower jaw. The dentist can then see premature contacts and interferences that are hard to spot in the mouth.

The examination is recommended before treatment that changes the bite long term: prosthetic work involving six to eight or more units, full-mouth restoration, raising the bite height, implant-supported prosthetics, and orthodontic treatment in adults. The second group of indications is symptoms: pain or clicking in the joint, restricted mouth opening, morning jaw stiffness, pathological tooth wear, bruxism, repeated chipping of ceramics and crowns coming loose.

Sometimes the full protocol is not needed. A single filling, caries treatment, a professional clean and often a single crown on a back tooth can be handled with a routine examination, provided the bite is stable and the joint is healthy. Nor is the examination a treatment in itself: it does not relieve pain, and it replaces neither orthodontic assessment with a cephalogram nor implant planning. If you have acute pain, trismus or a recent jaw injury, that is treated first and the measurements are taken later.

MediUkraine is a treatment search and coordination service, not a clinic. We choose the dental centre and a doctor with the right specialism, arrange the appointment dates and support you throughout, including if you are travelling from abroad. Decisions on the diagnosis and the scope of treatment are made by the doctor after an in-person examination.

The face-bow is the first instrument of the protocol. It is a frame positioned using landmarks on the skull: ear pieces sit in the ear canals and a third support rests on a point on the nose or below the eye socket. The bow records the angle at which the upper jaw sits and its distance from the joints, and transfers this relationship to the articulator. Without it the models are mounted arbitrarily, and any error in the tilt of the occlusal plane ends up as a contact that is too high or too low on the finished restoration. A kinematic face-bow, unlike an anatomical one, locates the patient's true hinge axis rather than relying on average points.

Registration of centric relation is the second key stage. Centric relation is the position in which the condyles sit in the upper front part of the joint sockets, and it does not always match the way the teeth habitually close: over the years the muscles have learned to steer the jaw into a comfortable position that avoids interferences. Deprogrammers are used to erase this muscle memory: an anterior JIG, a leaf gauge, a Kois deprogrammer, a bite plate. Some work within minutes, others have to be worn for several days. The resulting position is captured with a silicone or wax bite record.

The articulator imitates the movement of the temporomandibular joints outside the mouth. Average-value instruments work with averaged values for the condylar guidance angle and the Bennett angle, while fully adjustable ones are set individually from the data of an instrumental recording. For a single crown on a back tooth, averaged values are usually enough; for a full-mouth reconstruction they are not, because even a small error is then multiplied across every tooth in the arch. In the instrument the dentist sees premature contacts, interferences on the working and balancing sides, and the pattern of guidance when the jaw moves forward.

Axiography and condylography record the path of movement of the condyle. Mechanical systems draw a graph on a plate, while electronic ones capture the movement with sensors and plot the curve on screen. The recording gives individual angles for programming the articulator and shows any asymmetry between the right and left joints. The method has a clear limit: axiography records movement, not the condition of the tissues, and it cannot replace imaging of the articular disc.

Imaging shows what a clinical examination cannot. Cone beam computed tomography shows the bony structures: the shape and size of the condyle, its position in the socket, erosions, flattening, and the condition of the teeth and the bone around them. MRI is the only method that shows the articular disc itself and whether it is displaced with or without reduction. An orthopantomogram and a cephalogram are added when the plan includes an orthodontic stage.

The clinical examination matters just as much as the instruments. The dentist palpates the chewing and temporal muscles, assesses tenderness at specific points, measures how wide the mouth opens (roughly 40–55 mm is typical in adults), checks whether the jaw moves straight or deviates to the side, listens for clicking and crepitus, and performs joint loading tests. Many clinics work to the structured DC/TMD protocol, which combines a standardised questionnaire with a systematic examination and gives results that can be compared between doctors.

Digital tools complement the classic methods. An intraoral scanner produces models without impression material, a face scan and a photo record link the teeth to the facial features, and a virtual articulator allows the bite to be analysed in software. T-Scan computerised occlusal analysis shows not only where contact occurs but also in what sequence and with what relative force, while electromyography assesses the activity of the chewing muscles. Both are supplementary: a diagnosis is never based on them alone, and the clinic should be upfront about this.

The findings are then turned into a physical plan. In the programmed articulator the technician creates a wax-up of the planned tooth shape, which is transferred into the mouth as a trial mock-up so you can see and assess it before any teeth are prepared. If the plan involves changing the bite height or there is joint dysfunction, a Michigan-type stabilisation splint is made first and usually worn for 6–12 weeks under the dentist's supervision, and only then does treatment move on to temporary restorations.

It is important to be clear about the limits of the method. The examination describes how the bite is arranged, but it does not prove that the bite caused the pain: scientific evidence does not confirm that features of occlusion are the sole cause of temporomandibular joint dysfunction. That is why current clinical guidelines advise starting with reversible measures, a splint, exercises, physiotherapy and adjusting the load, and considering irreversible interventions such as selective grinding or full-mouth prosthetics "to treat the joint" with caution and only for specific indications. Clicking without pain and without restricted movement often needs no treatment at all, only monitoring.

Related treatments usually come after this stage: orthodontic treatment with aligners or braces corrects the position of the teeth, and the prosthetic stage restores their shape with crowns, veneers or implant-supported restorations. The functional examination replaces none of them: it sets the coordinates within which this work is done and the order in which it is done.

You get the dentist's preliminary findings straight after the appointment; the full report takes three to seven working days, because the models have to be cast, mounted in the articulator and analysed, and the imaging reported. That is why the plan is usually presented at a separate visit rather than on the day of the measurements.

If a stabilisation splint is prescribed, it is made within three to seven days. For the first few days your bite will feel unusual, and you may notice extra saliva and slightly unclear speech on some sounds; this usually settles within a few days. The first adjustment is made after 1–2 weeks, and after that the splint is checked once every 4–6 weeks, because the muscles relax and the jaw gradually changes position.

The effect of reversible therapy is usually assessed after at least 6–12 weeks of regular wear. Muscle pain in most cases eases sooner, within 4–8 weeks, whereas clicking caused by a displaced articular disc may persist: the aim of treatment is to remove the pain and restore a normal range of movement, not necessarily to get rid of the sound.

The dentist will also warn you that your bite is expected to change. When the muscles stop holding the jaw in its habitual position, the teeth start to meet differently, and this is not a complication but precisely the aim of this stage. This new position then becomes the basis for prosthetic or orthodontic treatment.

Permanent restorations are almost always preceded by temporary ones, which are used to test the new bite height and tooth shape over 4–12 weeks, and sometimes longer in a full-mouth reconstruction. If anything feels uncomfortable during this time, the temporaries are adjusted: reworking acrylic is much easier than reworking ceramics.

Once the prosthetic work is complete, check-ups are scheduled after one month, after six months and then once a year to check the occlusal contacts, the ceramics and the muscles. Timeframes and progress vary from person to person, so only a dentist can predict the outcome for an individual patient, based on an examination and its findings.