The Kennedy classification quantifies partial edentulism. An outline is covered at the removable partial denture article.

Nabers probe is used to check for furcation involvement clinically. Recently, cone beam computerised technology (CBCT) has also be used to detect furcation. Periapical and interproximal intraoral radiographs can help diagnosing and locating the furcation. The location and severity of furcation should be recorded in patient’s notes.

Only multirooted teeth have furcation. Therefore, upper first premolar, maxillary and mandibular molars may be involved.

Upper premolars have one buccal and one palatal root. Furcation involvement should be checked from the mesial and the distal aspects of the tooth.

Maxillary molars have three roots, a mesio-buccal root, disto-buccal root and a palatal root. Thus, check for furcation from buccal, mesio-palatal and disto-palatal aspects.

Mandibular molars have one mesial and one distal root, and so, check for involvement from buccal and lingual aspects.

A child with posterior crossbite should be treated immediately if the child shifts his mandible on closing which is often seen in a unilateral crossbite as mentioned above. The best age to treat a child with crossbite is in their mixed dentition when their palatal sutures have not fused to each other. Palatal expansion allows more space in an arch to relieve crowding and correct posterior crossbite. The correction can include any type of palatal expanders that will expand the palate which resolves the narrow constriction of the maxilla. There are several therapies that can be used to correct a posterior crossbite: braces, 'Z' spring or cantilever spring, quad helix, removable plates, clear aligner therapy, or a Delaire mask. The correct therapy should be decided by the orthodontist depending on the type and severity of the crossbite.

One of the keys in diagnosing the anterior crossbite due to skeletal vs dental causes is diagnosing a CR-CO shift in a patient. An adolescent presenting with anterior crossbite may be positioning their mandible forward into centric occlusion (CO) due to the dental interferences. Thus finding their occlusion in centric relation (CR) is key in diagnosis. For anterior crossbite, if their CO matches their CR then the patient truly has a skeletal component to their crossbite. If the CR shows a less severe class 3 malocclusion or teeth not in anterior crossbite, this may mean that their anterior crossbite results due to dental interferences.

Goal to treat unilateral crossbites should definitely include removal of occlusal interferences and elimination of the functional shift. Treating posterior crossbites early may help prevent the occurrence of Temporomandibular joint pathology.

Unilateral crossbites can also be diagnosed and treated properly by using a Deprogramming splint. This splint has flat occlusal surface which causes the muscles to deprogram themselves and establish new sensory engrams. When the splint is removed, a proper centric relation bite can be diagnosed from the bite.

Crowding of the teeth is treated with orthodontics, often with tooth extraction, clear aligners, or dental braces, followed by growth modification in children or jaw surgery (orthognathic surgery) in adults. Surgery may be required on rare occasions. This may include surgical reshaping to lengthen or shorten the jaw (orthognathic surgery). Wires, plates, or screws may be used to secure the jaw bone, in a manner similar to the surgical stabilization of jaw fractures. Very few people have "perfect" alignment of their teeth. However, most problems are very minor and do not require treatment.

Literature states that very few crossbites tend to self-correct which often justify the treatment approach of correcting these bites as early as possible. Only 0–9% of crossbites self-correct. Lindner et al. reported that in a 50% of crossbites were corrected in 76 four year old children.

To establish appropriate alignment and occlusion, the sizes of upper and lower front teeth, or upper and lower teeth in general, need to be proportional. Inter-arch tooth size discrepancy (TSD) is defined as a disproportion in the mesio-distal dimensions of teeth of opposing dental arches, which can be seen in 17% to 30% of orthodontic patients.

Geoffrey Greenlee and others published a meta-analysis in 2011 which concluded that patients with orthognathic surgical correction of open bite had 82% stability in comparison to non-surgical correction of open bite which had 75% of stability after 1or more year of treatment. Both the groups started with 2-3mm of open bite initially.

The treatment aims are to eliminate the bacteria from the exposed surface of the root(s) and to establish the anatomy of the tooth, so that better plaque control can be achieved. Treatment plans for patients differ depending on the local and anatomical factors.

For Grade I furcation, scaling and polishing, root surface debridement or furcationplasty could be done if suitable.

For Grade II furcation, furcationplasty, open debridement, tunnel preparation, root resection, extraction, guided tissue regeneration (GTR) or enamel matrix derivative could be considered.

As for Grade III furcation, open debridement, tunnel preparation, root resection, GTR or tooth extraction could be performed if appropriate.

Tooth extraction is usually considered if there is extensive loss of attachment or if other treatments will not obtain good result (i.e. achieving a nice gingival contour to allow good plaque control).

Man-Suk Baek and others evaluated long-term stability of anterior open bite by intrusion of maxillary posterior teeth. Their results showed that the molars were intruded by 2.39mm during treatment and relapsed back by 0.45mm or 22.8%. The incisal overbite increased by 5.56mm during treatment and relapsed back by 1.20mm or 17%. They concluded that majority of the relapse occurred during first year of treatment.

Edentulism affects approximately 158 million people globally as of 2010 (2.3% of the population). It is more common in women at 2.7% compared to the male rate of 1.9%.

A cross-sectional analysis of data from the Survey of Health, Ageing and Retirement in Europe (SHARE) from 14 European countries (Austria, Belgium, Czech Republic, Denmark, Estonia, France, Germany, Italy, Luxembourg, the Netherlands, Slovenia, Spain, Sweden, and Switzerland) and Israel showed substantial variation in the age-standardized mean numbers of natural teeth amongst people aged 50 years and older, ranging from 14.3 teeth (Estonia) to 24.5 teeth (Sweden). The oral health goal of retaining at least 20 teeth at age 80 years was achieved by 25% of the population or less in most countries. A target concerning edentulism (≤15% in population aged 65–74 years) was reached in Sweden, Switzerland, Denmark, France, and Germany. Tooth replacement practices varied especially for a number of up to five missing teeth which were more likely to be replaced in Austria, Germany, Luxembourg, and Switzerland than in Israel, Denmark, Estonia, Spain, and Sweden.

The prevalence of Kennedy Class III partial denture was predominant among younger population of 21-30 year and 31–40 years, whereas in group III between 41 and 50 years Class I was predominant. It can be stated that the need for prosthodontics care is expected to increase with age, and hence, more efforts should be made for improving dental education and motivation among patients.

Edentulism occurs more often in people from the lower end of the socioeconomic scale.

In disease states, maxillary prognathism is associated with Cornelia de Lange syndrome; however, so-called false maxillary prognathism, or more accurately, retrognathism, where there is a lack of growth of the mandible, is by far a more common condition.

Prognathism, if not extremely severe, can be treated in growing patients with orthodontic functional or orthopaedic appliances. In adult patients this condition can be corrected by means of a combined surgical/orthodontic treatment, where most of the time a mandibular advancement is performed. The same can be said for mandibular prognathism.

The most common treatment for mandibular prognathism is a combination of orthodontics and orthognathic surgery. The orthodontics can involve braces, removal of teeth, or a mouthguard.

The surgery required has led, in some cases, to identity crises in patients, whereby the new facial structure has a negative impact mentally on how the patients perceive themselves.

Overbite medically refers to the extent of vertical (superior-inferior) overlap of the maxillary central incisors over the mandibular central incisors, measured relative to the incisal ridges.

The term overbite does not refer to a specific condition, nor is it a form of malocclusion. Rather an absent or excess overbite would be a malocclusion. Normal overbite is not measured in exact terms, but as a proportion (approximately 30–50% of the height of the mandibular incisors) and is commonly expressed as a percentage.

Repair with cementum or dentin occurs after partial root resorption, fusing the tooth with the bone. It may occur following dental trauma, especially occlusal trauma, or after periapical periodontitis caused by pulp necrosis. Ankylosis itself is not a reason to remove a permanent tooth, however teeth which must be removed for other reasons are made significantly more difficult to remove if they are ankylosed.

Macroglossia is usually diagnosed clinically. Sleep endoscopy and imaging may be used for assessment of obstructive sleep apnea. The initial evaluation of all patients with macroglossia may involve abdominal ultrasound and molecular studies for Beckwith–Wiedemann syndrome.

Ankylosis of deciduous teeth ("submerged teeth") may rarely occur. The most commonly affected tooth is the mandibular (lower) second deciduous molar. Partial root resorption first occurs and then the tooth fuses to the bone. This prevents normal exfoliation of the deciduous tooth and typically causes impaction of the permanent successor tooth. As growth of the alveolar bone continues and the adjacent permanent teeth erupt, the ankylosed deciduous tooth appears to submerge into the bone, although in reality it has not changed position. Treatment is by extraction of the involved tooth, to prevent malocclusion, periodontal disturbance or dental caries.

Overbite is often confused with overjet, which is the distance between the maxillary anterior teeth and the mandibular anterior teeth in the anterior-posterior axis.

"Overbite" may also be used commonly to refer to Class II malocclusion or retrognathia, though this usage can be considered incorrect. This is where the mesiobuccal cusp of the maxillary first molar is situated anterior to the buccal groove of the mandibular first molar; in other words, the mandible (lower jaw) appears too far behind the maxilla. A person presenting with Class II malocclusion may exhibit excessive overbite as well, or may have the opposite problem, which is referred to as openbite (or apertognathia). In the case of apertognathia, the teeth do not overlap enough or at all. The upper teeth protrude past the lower teeth.

Prosthetic replacement of missing teeth is possible using dental implant technology or dentures. This treatment can be successful in giving patients with anodontia a more aesthetically pleasing appearance. The use of an implant prosthesis in the lower jaw could be recommended for younger patients as it is shown to significantly improve the craniofacial growth, social development and self-image. The study associated with this evidence worked with individuals who had ectodermal dysplasia of varying age groups of up to 11, 11 to 18 and more than 18 years. It was noted that the risk of implant failure was significantly higher in patients younger than 18 years, but there is significant reason to use this methodology of treatment in those older. Overall the use of an implant-prosthesis has a considerable functional, aesthetic and psychological advantage when compared to a conventional denture, in the patients.

Computed tomography is the most sensitive and specific of the imaging techniques. The facial bones can be visualized as slices through the skeletal in either the axial, coronal or sagittal planes. Images can be reconstructed into a 3-dimensional view, to give a better sense of the displacement of various fragments. 3D reconstruction, however, can mask smaller fractures owing to volume averaging, scatter artifact and surrounding structures simply blocking the view of underlying areas.

Research has shown that panoramic radiography is similar to computed tomography in its diagnostic accuracy for mandible fractures and both are more accurate than plain film radiograph. The indications to use CT for mandible fracture vary by region, but it does not seem to add to diagnosis or treatment planning except for comminuted or avulsive type fractures, although, there is better clinician agreement on the location and absence of fractures with CT compared to panoramic radiography.

There are various classification systems of mandibular fractures in use.

Also called myofunctional therapy, the basic treatment aims of orofacial myofunctional therapist is to reeducate the movement of muscles, restore correct swallowing patterns, and establish adequate labial-lingual postures. An interdisciplinary nature of treatment is always desirable to reach functional goals in terms of swallowing, speech, and other esthetic factors. A team approach has been shown to be effective in correcting orofacial myofunctional disorders. The teams include an orthodontist, dental hygienist, certified orofacial myologist, general dentist, otorhinolaryngologist, and a speech-language pathologist.

Orofacial myofunctional disorders (OMD) (sometimes called “oral myofunctional disorder", and “tongue thrust”) are muscle disorders of the face, mouth, lips, or jaw.

Recent studies on incidence and prevalence of tongue thrust behaviors are not available. However, according to the previous research, 38% of various populations have OMD. The incidence is as high as 81% in children exhibiting speech/articulation problems (Kellum, 1992).

Treatment and prognosis of macroglossia depends upon its cause, and also upon the severity of the enlargement and symptoms it is causing. No treatment may be required for mild cases or cases with minimal symptoms. Speech therapy may be beneficial, or surgery to reduce the size of the tongue (reduction glossectomy). Treatment may also involve correction of orthodontic abnormalities that may have been caused by the enlarged tongue. Treatment of any underlying systemic disease may be required, e.g. radiotherapy.

Treatment is surgical, and usually is able to be performed once life-threatening injuries are stabilized, to allow the patient to survive the general anesthesia needed for invasive orthopedic restructuring. First a "frontal bar" is used, which refers to the thickened frontal bone above the frontonasal sutures and the superior orbital rim. The facial bones are suspended from the bar by open reduction and internal fixation with titanium plates and screws, and each fracture is fixed, first at its superior attachment to the bar, then at the inferior attachment to the displaced bone. For stability, the zygomaticofrontal suture is usually replaced first, and the palate and alveolar ridge are usually fixed last. Finally, after the horizontal and vertical maxillary buttresses are stabilized, the orbital fractures are fixed last.

Overjet is the extent of horizontal (anterior-posterior) overlap of the maxillary central incisors over the mandibular central incisors. In class II (division I) malocclusion the overjet is increased as the maxillary central incisors are protruded.