Jaw abnormality

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Jaw abnormality
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Specialty Oral & Maxillofacial surgery

A jaw abnormality is a disorder in the formation, shape and/or size of the jaw. In general abnormalities arise within the jaw when there is a disturbance or fault in the fusion of the mandibular processes. The mandible in particular has the most differential typical growth anomalies than any other bone in the human skeleton. This is due to variants in the complex symmetrical growth pattern which formulates the mandible. [1]

Contents

The mandible in particular plays a significant role in appearance as it is the only moving part of the facial skeleton. This has a large impact upon an individual's ability to speak, masticate and also influence their overall aesthetic and expressive features of the face. In turn the maxilla faces the same issues if any abnormalities in size or position were to occur. [2] The obvious functional disabilities that arise from jaw abnormalities are very much physically seen as previously stated, but when considering these individuals it must be kept in mind that these conditions may well affect them psychologically; making them feel as though they are handicapped. [3]  It is also of the utmost importance when correcting these mandibular anomalies that the teeth result in a good occlusion with the opposing dentition of the maxilla. If this is not done satisfactorily occlusal instability may be created leading to a plethora of other issues. In order to correct mandibular anomalies it is common for a complex treatment plan which would involve surgical intervention and orthodontic input.  

Signs and symptoms

Individuals with jaw abnormalities have both functional [4] [5] and aesthetic [4] [5] [6] [7] [8] [9] [10] [11] impairment. [12]

Misalignment of teeth creates difficulties in head and neck functions related to chewing, [6] [7] [8] swallowing, breathing, speech articulation [6] [7] [8] and lip closure/posture. [13]

Affected individuals may also experience TMJ pain and dysfunction, [7] [14] which negatively affect the quality of life. [15]

A proportion of affected individuals also have psychological problems. [16]

Diagnosis

Diagnosis of a jaw deformity is a structured process, linking the undertaking of a history, physical examination of the patient, and appraisal of diagnostic studies. This process may involve more than a single discipline of Dentistry – in addition to orthodontic and surgical needs, some patients may also require periodontal, endodontic, complex restorative, and prosthetic considerations. [17]

It involves the chief presenting complaint of the patient, which allows the clinician to understand the patient's perception of the problem – what they think the problem is and what they would like corrected. The patient may find eating difficult or may have problems with speech or the appearance of the teeth or face. However, patients may be hesitant to discuss dissatisfaction with their appearance because they may feel that it is more acceptable to present a functional problem to the clinician. For this reason it is important to reassure patients that their aesthetic problems and the effects of these are perfectly valid concerns. In children, psychological development can be affected due to teasing if they have abnormal appearance of teeth or face. Correction of the abnormality can be extremely beneficial to the patient. The benefits can manifest themselves in many ways including improved peer relationships and social confidence. Motivation on the patient's part is necessary if they are going to undergo lengthy orthodontic treatment and major surgery. In addition, they need to be well informed so that they may give valid consent. In terms of history, the family history and perhaps obstetric history may be relevant, especially when features of a syndrome are present. [18] : 200 

A medical and dental history is obtained for completeness. The medical history includes questions on the general health of the patient, to assess contraindications to treatment of jaw abnormality. Special emphasis is placed on diseases and medication which cause altered metabolism, that may affect growth and tissue reactions. [19] Allergies are checked (specifically nickel allergies), so that treatment appliances with nickel-containing materials like stainless steel can be replaced with other materials to avoid the risk of allergic reactions. [20] Questions on family history are also relevant, as malocclusions, growth and development may be expressions of genetic patterns. [19] The dental history investigates if the patient has had any previous dental trauma, or past dental experiences, which can serve as a gauge to patient compliance with treatment.

Examination

The assessment of facial form includes the evaluation of facial soft tissue and dentition. As the human skeleton is not visibly perceptible, bone deformity is inferred and evaluated by facial appearance and dentition. [21] To obtain a 3D assessment of the patient, the skeletal pattern must be measured in different planes: anterior-posterior, vertical, and transverse. This allows for an accurate assessment of the size, position, orientation, shape, and symmetry of the jaws.  

The anterior-posterior skeletal pattern measures the relationship of the lower jaw to the upper jaw. This is judged with the patient seated upright, head in a neutral horizontal position, and teeth in gentle occlusion. It can be classified into the following classes:

The vertical dimension can be measured by facial thirds, with ideal facial aesthetics showing equality between each vertical third. [22] The face is divided into thirds – hairline to glabella; glabella to subnasale; and subnasale to the lowest part of the chin. Two other clinical indicators can be assessed when analysing vertical dimensions, namely the Frankfort Mandibular Planes Angle (FMPA) and the Lower Facial Height (LFH) – both of which are each recorded as either average, increased, or decreased.

The transverse relationship is a measure of jaw or facial asymmetry. It checks for the alignment of the soft tissue nasion, the middle part of the upper lip at the vermillion border, and the chin point. If present, it is necessary to distinguish between a false and true asymmetry. [23] A false asymmetry arises due to occlusal interferences, which results in a lateral displacement of the mandible, producing a cross-bite in the anterior/buccal region. Elimination of the displacement will return the mandible to a centric position. On the other hand, a true asymmetry indicates unequal facial growth on the left or right side of the jaws. Elimination of any occlusal cross-bites is not only difficult, but unlikely to improve the facial asymmetry. The assessment of the transverse components of the facial width is best described by the "rule of fifths", [24] which sagittally divides the face into five equal parts: [25]

Tests

It is insufficient to derive at a diagnosis of jaw deformity solely based on the clinical examination. Hence, additional information is gathered from diagnostic tests, which may include dental model analyses and radiographic imaging studies.

  1. Dental Model Analyses - Study models for analysis can be made by taking dental impressions, or by 3D intra-oral scanning. They allow for the appraisal of shape and size of jaws and teeth. This can be valuable for the long-term evaluation of development and for the follow-up of treatment results. Depending on the type of jaw abnormality, a face bow record for transfer on to the articulator, can sometimes be appropriate for the patient. [26]
  2. Radiographs - Radiographic investigations should be based on individual needs and used in conjunction to the clinical examination. As with all other dental radiographs, the benefit gained for the patient with the radiograph must be weighed against the radiation dosage of taking it. [27] In the assessment of jaw abnormalities, the most common radiographs taken used to be the dental panoramic tomography and lateral cephalometry. With the advancement in technology, the use of 3D imaging e.g. Cone Beam Computed Tomography (CBCT) has gained popularity for the use of radiographic examinations of facial bones for purpose of planning complex orthognathic surgery, especially involving significant facial asymmetry. [17] A 3D facial construction model can be utilised in more complex malocclusion to help plan management. [28]

Classification

Size

Mandibular micrognathia is the condition when lower jaw is smaller than normal. [29] Failure of the ramus to develop will give rise to micrognathia. [30] Micrognathia can be classified as either congenital or acquired. Clinical appearance of some patients with congenital type of mandibular micrognathia can have a severe retrusion of the chin but by actual measurements, the mandible maybe be found to be within the normal limits of variation. This may be because a posterior placing of the condylar head with regard to the skull or to a steep mandibular angle resulting in an evident jaw retrusion. The acquired type of micrognathia occurs after birth and usually is an effect of a disturbance to temporomandibular joint. Growth of mandible depends on the normally developing condyles and the muscle function For example, trauma or infection that affect mastoid, middle ear or the joint will result in ankylosis of temporomandibular joint leading to mandibular micrognathia. [31]

Macronagthia is a condition of abnormally large jaws. The jaw size is usually proportion to the increase in skeleton size. [31] It is usually due to excessive growth of the mandible and can have features including reverse maxillary to mandibular relationship, reverse overjet or absence of overbite. [30] It can also be clinically presented when the glenoid fossa and condylar head is more anteriorly placed, causing mandibular prognathism. [32] Macronagthism can be associated with other medical conditions :-

1.    Paget's disease where there is overgrowth of the maxilla, cranium and mandible [31]

2.    Acromegaly, an endocrine disease, can present with enlargement of bones with growth potential such as the mandible, thickened soft tissues and facial features and spade-like hands [33]

Macrogenia and microgenia occur when there is a normal skeletal relationship but the chin, skeletal and soft tissue components, failed to develop in proportion to the skeletal base, resulting in marked protrusive (macrogenia) or retrusive (microgenia) facial profile. Microgenia can be presented when there is inadequate bone depth at the apex of lower anteriors or the base of mandible and vice versa. [30]

Position

A transverse jaw position is known as Laterognathia. This term describes a lateral bite in the lower jaw [34] and is often associated with a unilateral crossbite at an early age [35] This can lead to bone development of an asymmetrical mandibular ramus resulting in asymmetry in the whole of the lower face. [36] Treatment of laterognathism is either possible with orthodontic tooth movement or a surgical relocation of the lower jaw. [37]

One of the ways in which a jaw can develop abnormally is in the vertical dimension. Abnormal growth can occur in the maxilla and the mandible. The jaw is usually loosely used to refer to the mandible (considered the lower jaw). However, the maxilla is also a jaw and should thus be referred to in this respect as well.

The vertical jaw abnormalities relating to the mandible are in relation to excessive vertical growth and excessive horizontal growth, measured by the maxillary-mandibular plane angle (MMPA). The vertical jaw abnormalities relating to the maxilla are in relation to excessive downward displacement (EDD) and insufficient downward displacement (IDD). These terms used to previously be known as vertical maxillary excess and deficiency. This nomenclature changed because excess and deficiency typically refer to size. Whereas when assessing this clinically, one would measure the distance between the central incisors and the upper lip, which, in fact, denotes position rather than size. Therefore, in order to ‘harmonize with geometry’, EDD and IDD are now used widely. [38]

Vertical and Horizontal Mandibular Excess:

Simply put, excessive vertical growth is the term used for when the mandible is considered ‘too far down. [39] Whereas in excessive horizontal growth the opposite applies, where the mandible is growing in a more horizontal pattern, in relation to the maxilla. The primary cause of the above two abnormalities in adolescents is due to accelerated and slow mandibular growth. Resulting in either a longer lower face height appearance (vertical growth) or a shorter one (horizontal growth). The length between the columella (base of the nose) and menton (base of the chin) is the variable measurement. This is in relation to the length between the glabella (between eyebrows) and the columella. In a normal case, these lengths would be equal or without a major discrepancy. However, in excess vertical and horizontal growth, the proportions vary and do not equal.

The development of the mandible is such that it ossifies in two primary ways; endochondrally and intramembranously. Almost the entire mandible is formed via intramembranous ossification, with just the condyle ossifying endochondrally. This allows the condyle to resist forces exerted on it. One way in which a vertical jaw abnormality can occur is if the condylar growth process is damaged, and thus the intramembranous growth continues along the posterior condylar margin, becoming predominant, thus resulting in a high angle type. [40]

Assessing a patient for vertical and horizontal excess

The Maxillary Mandibular Plane Angle (MMPA) is important in assessing a patient for vertical jaw abnormality. The important landmarks are the Frankfurt plane and the Mandibular plane. The Frankfurt plane is a line charted from the upper border of external auditory meatus to the lower border of the orbit. It is similar to the ala-tragus line however should not be confused with it. Whereas the Mandibular angle is a line measured along the natural lower border of the patient's mandible. The intersection of the Frankfurt and Mandibular plane is what determines the pattern of vertical growth. If the intersection occurs behind the occiput i.e. decreased angle, then the patient is considered to have horizontal growth. On the other hand, if the intersection occurs in front of the occiput, then the patient is considered to have vertical growth. The normal range is considered to be between 25 and 30 degrees in a typical Caucasian person. Those with excess vertical jaw growth are most often seen having an anterior open bite, as the mandible is growing away from the maxilla. Whereas those with excessive horizontal growth are seen as having an overbite.

Excessive Downward Displacement and Insufficient Downward Displacement

Here on, we will use interchangeably the terms vertical maxillary excess and deficiency with excessive and insufficient downward displacement. In order to understand its manifestations, we need to account for key landmarks such as: [41]

· Columella (CM)– The tissue that links the nasal tip to the nasal base, separating the nares. The inferior margin of the nasal septum

· Subnasale (SN) – the junction of the upper lip and the columella

· Stomion Superios (Sts) – the lower most point on the vermillion of the upper lip

· Stomion (Sto) – The point of contact, when lips are competent, in the midline, between the top and bottom lip

· Stomion Inferious (Sti) – the upper most point on the vermillion of the lower lip

· Soft tissue mention (Me) – The most inferior point on the soft tissue outline of the chin

The measurements of the upper lip and lower lip for each patient are ascertained by using the aforementioned landmarks. The length of the upper lip is measured from Sn to Sts. In a typical male and female this measures to 24mm and 21mm respectively (REF). The length of the lower lip is measured from Sti to Me. In a typical male and female this measures to 50mm and 46.5mm respectively. [41]

When considering EDD and IDD, the class of the skeletal base is a good adjunct. In other words, EDD and IDD can either appear camouflaged or apparent given the skeletal base and the soft tissue profile accompanying it. For example, the drape of the upper lip can mask the maxillary deficiency to such an extent that it presents as a normal soft tissue profile (REF). Para-nasal hollowing is a key indicator of underlying maxillary deficiency. It is most common in class III patients, but can also present in some class II cases, with bilateral maxillary retrusion. [41]

Assessing a patient for vertical and horizontal excess:

Arguably the main observation to carry out in a patient to assess maxillary excess or deficiency is the upper incisor/gum show when at rest and smiling. In other words, the relationship between the upper lip and upper central incisors when at rest and smiling. [41]   Ensure the patient's head posture is correct and the lips are at rest to establish the resting lip line. Similarly, to assess the incisor/gum show on smiling, the patient needs to fully smile to allow the upper lip to rise to its maximum height. The average showing of the incisors when the lips are at rest is 1/3 of its clinical crown height. With maxillary excess, more than 1/3 of the incisors would show. When the patient smiles, maxillary excess would manifest as the entire clinical crown and a portion of the gums showing as well. [42] This is regarded as a ‘gummy smile.’

As alluded to previously, the paranasal region is important to consider when assessing a patient for IDD or EDD. Observing the patient from the side view allows a clearer perspective. A lack of bony support for the soft tissues in this region will subsequently produce the depression, known as paranasal hollowing. [42] This indicates a low level antero-posterior maxillary deficiency. Maxillary deficiency usually manifests as an increased naso-labial angle, although this is not a credible indication due to factors such as a short upper lip and/or proclined incisors.

Another method to predict if a patient has maxillary deficiency is by the ‘scleral show and eyelid shape.’ The lower eyelid normally rests at the inferior border of the iris, without any sclera showing. If there is any sclera showing, then this is a good sign of infraorbital rim deficiency and maxillary antero-posterior deficiency, two manifestations that are usually seen in Class III patients. [42]

Orientation

When a jaw is abnormally oriented, malrotations occur. These malrotations are classified according to the axis on which the abnormal rotation occurs. When a jaw is malrotated around the transverse facial axis, it is said to have abnormal pitch. When malrotated around the anteroposterior axis, the jaw has an abnormal roll, a condition also known as cant.  Finally, when a jaw is malrotated around the vertical axis, it has abnormal yaw. It can occur in maxilla and/or mandible and could result due to abnormal growth of the jaws in itself or as compensatory growth. [43]

Shape

Shape refers to figure, the geometric characteristic of an object that is not size, position, or orientation 5.  A jaw with abnormal shape is said be distorted. [44]

Completeness

Completeness means the wholeness of the jaw. [45] When failure of tissues to fuse together that are forming early in pregnancy, defect can happen and jaw is incomplete. [46] For example, cleft lip and palate when one of the jaw's embryological processes failed to fuse together or the agenesis of the condylar process of the mandible, which may be seen in hemifacial microsomia. [46] Clinically, cleft palate  presents as opening in the palate that can affect the front palate only or extending from the front to the back palate. [47] Cleft lip is presented clinically with opening of the upper lip which can be a small slit on the upper lip or large opening connected to the nose. [47] The cleft can be unilateral on the upper lip or bilaterally. [48] Cleft lip can happen together with cleft palate. [47]

Palatal clefts are one of the most common congenital abnormalities which occur in 1:2500 live births. [46] Embryologically, palate formation takes place in two stages, with the primary palate formed after 6th week followed by secondary palate formation between sixth and eighth weeks. [46] The palate will fuse with the medial nasal process to form the roof of the mouth in order to complete the developmental process. [12] However, if this process is incomplete that is when developmental defect occur. [46] Initially, it is just a common oro-nasal cavity within the embryo with nothing to separate the nose and mouth cavity. [46] This space is occupied with tongue. [46] The primary palate formed when medial nasal prominences fused together to form the intermaxillary segment to demarcate the oral from the nasal components. [46] The formation of secondary palate starts with the growing of tissues vertically and mesially forming the right and left lateral palatal shelves. [46] On the week 8, the tongue will be withdrawn downwards and the right and left lateral palatal shelves will be rapidly elevated, flipped into a horizontal orientation and fuse together from the front to the back two. [46] The right and left lateral palatal shelves contact or fuse with each other at the midline to form the secondary palate two. [46]

A lot of growth factors are actively involved in the signalling to the tissues during craniofacial development. [49] These growth factors function to control the cells proliferation, survival and apoptosis. [49] Some of the growth factors that can be implicated in the facial development resulting in craniofacial defect are BMP, FGF, Shh, Wnt and endothelins. [49] One of the environmental factors that has been identified in mice study to have link to cleft lip is teratogen which can interfere the molecular signalling between the growth factors. [48] However, the exact mechanism is still not clear. [48] Another environmental factors that has been actively involved in studies to prevent cleft lip and palate occurrences is the intake of folic acid during pregnancy. [50] 0.4 mg folic acid intake per day has been shown to reduce one third risk of cleft lip (with or without cleft palate) in babies. [50] However, it seems had no apparent effect on the risk of cleft palate alone. [50] There are also studies in mice and dogs reported the protective effect of folic acid supplementation to prevent cleft lip palate occurrence. [48]

Treatment

Jaw abnormalities are commonly treated with combined surgical (orthognathic surgery) and orthodontic treatment. [12] The procedure is carried out by oral and maxillofacial surgeons and orthodontists in close collaboration. [51]

In most cases, the orthodontist will first align the teeth with braces or other appliances, which may worsen the occlusion until after the surgery. [51] This is carried out to show the full degree of abnormality, and to create sufficient space for full correction in the bones. [51]

Orthognathic surgery, also known as corrective jaw surgery, is performed to normalise dentofacial deformity and reposition part/all of the upper and/or lower jaws to improve occlusion stability and facial proportions. [12] [51] It is the 'mainstay treatment for patients who are too old for growth modification and for dentofacial conditions that are too severe for either surgical or orthodontic camouflage.' [52]

The surgery usually involves gaining access to the bone from inside the mouth, revealing and moving the bone into a correct functional position, and fixing it in position with metal plates and screws. [53] These plates are most often left in the bone, but at times require removal due to infection, which would require another operation. [53]  Most orthognathic surgeries are performed inside the mouth without any external scarring. [53]

Mandibular surgery

There are numerous surgical techniques available to correct the position of the mandible. The most popular of these techniques is the sagittal split osteotomy which "enables the body of mandible to be moved forwards or backwards by sliding the split ramus and angle". [18] : 203  This provides a lot of bone overlap for healing. Damage to the inferior alveolar bundle is avoided by sectioning the buccal and retromolar cortex of the mandible and the cancellous bone is carefully split. After the mandible has been repositioned, screws or mini-plates can be used to fix the mandible directly. This is instead of fixing it indirectly with intermaxillary fixation (IMF). [18] : 203 

Genioplasty

Reduction or augmentation of the chin may be carried out either on its own or as part of a mandibular or maxillary orthognathic operation. [18] : 203 

Maxillary surgery

The Le Fort classification (which is used for fracture description) generally describes the surgical techniques which are used for maxillary surgery. [18] : 203 

Related Research Articles

Oral and maxillofacial surgery is a surgical specialty focusing on reconstructive surgery of the face, facial trauma surgery, the oral cavity, head and neck, mouth, and jaws, as well as facial cosmetic surgery/facial plastic surgery including cleft lip and cleft palate surgery.

<span class="mw-page-title-main">Prognathism</span> Protrusion of the upper or lower human jaw

Prognathism, also called Habsburg chin, Habsburg's chin, Habsburg jaw or Habsburg's jaw primarily in the context of its prevalence amongst members of the House of Habsburg, is a positional relationship of the mandible or maxilla to the skeletal base where either of the jaws protrudes beyond a predetermined imaginary line in the coronal plane of the skull. In general dentistry, oral and maxillofacial surgery, and orthodontics, this is assessed clinically or radiographically (cephalometrics). The word prognathism derives from Greek πρό and γνάθος. One or more types of prognathism can result in the common condition of malocclusion, in which an individual's top teeth and lower teeth do not align properly.

<span class="mw-page-title-main">Orthognathic surgery</span> Surgery of the jaw

Orthognathic surgery, also known as corrective jaw surgery or simply jaw surgery, is surgery designed to correct conditions of the jaw and lower face related to structure, growth, airway issues including sleep apnea, TMJ disorders, malocclusion problems primarily arising from skeletal disharmonies, and other orthodontic dental bite problems that cannot be treated easily with braces, as well as the broad range of facial imbalances, disharmonies, asymmetries, and malproportions where correction may be considered to improve facial aesthetics and self-esteem.

<span class="mw-page-title-main">Malocclusion</span> Medical condition

In orthodontics, a malocclusion is a misalignment or incorrect relation between the teeth of the upper and lower dental arches when they approach each other as the jaws close. The English-language term dates from 1864; Edward Angle (1855-1930), the "father of modern orthodontics", popularised it. The word "malocclusion" derives from occlusion, and refers to the manner in which opposing teeth meet.

<span class="mw-page-title-main">Hemifacial microsomia</span> Birth defect which affects the lower half of the face

Hemifacial microsomia (HFM) is a congenital disorder that affects the development of the lower half of the face, most commonly the ears, the mouth and the mandible. It usually occurs on one side of the face, but both sides are sometimes affected. If severe, it may result in difficulties in breathing due to obstruction of the trachea—sometimes even requiring a tracheotomy. With an incidence in the range of 1:3500 to 1:4500, it is the second most common birth defect of the face, after cleft lip and cleft palate. HFM shares many similarities with Treacher Collins syndrome.

<span class="mw-page-title-main">Palatal expansion</span> Orthodontics device to widen the upper jaw

A palatal expander is a device in the field of orthodontics which is used to widen the upper jaw (maxilla) so that the bottom and upper teeth will fit together better. This is a common orthodontic procedure. The use of an expander is most common in children and adolescents 8–18 years of age. It can also be used in adults, although expansion is more uncomfortable and takes longer in adults. A patient who would rather not wait several months for the end result achieved by a palatal expander may be able to opt for a surgical separation of the maxilla. Use of a palatal expander is most often followed by braces to then straighten the teeth.

<span class="mw-page-title-main">Distraction osteogenesis</span> Gradual bone lengthening

Distraction osteogenesis (DO), also called callus distraction, callotasis and osteodistraction, is a process used in orthopedic surgery, podiatric surgery, and oral and maxillofacial surgery to repair skeletal deformities and in reconstructive surgery. The procedure involves cutting and slowly separating bone, allowing the bone healing process to fill in the gap.

<span class="mw-page-title-main">Pierre Robin sequence</span> Medical condition

Pierre Robin sequence is a congenital defect observed in humans which is characterized by facial abnormalities. The three main features are micrognathia, which causes glossoptosis, which in turn causes breathing problems due to obstruction of the upper airway. A wide, U-shaped cleft palate is commonly also present. PRS is not merely a syndrome, but rather it is a sequence—a series of specific developmental malformations which can be attributed to a single cause.

Orthodontic technology is a specialty of dental technology that is concerned with the design and fabrication of dental appliances for the treatment of malocclusions, which may be a result of tooth irregularity, disproportionate jaw relationships, or both.

<span class="mw-page-title-main">Overjet</span> Medical condition

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

Cephalometric analysis is the clinical application of cephalometry. It is analysis of the dental and skeletal relationships of a human skull. It is frequently used by dentists, orthodontists, and oral and maxillofacial surgeons as a treatment planning tool. Two of the more popular methods of analysis used in orthodontology are the Steiner analysis and the Downs analysis. There are other methods as well which are listed below.

<span class="mw-page-title-main">Maxillary hypoplasia</span> Medical condition

Maxillary hypoplasia, or maxillary deficiency, is an underdevelopment of the bones of the upper jaw. It is associated with Crouzon syndrome, Angelman syndrome, as well as Fetal alcohol syndrome. It can also be associated with Cleft lip and cleft palate. Some people could develop it due to poor dental extractions.

Long face syndrome, also referred to as skeletal open bite, is a relatively common condition characterised by excessive vertical facial development. Its causes may be either genetic or environmental. Long face syndrome is "a common dentofacial abnormality." Its diagnosis, symptomology and treatments are complex and controversial. Indeed, even its existence as a "syndrome" is disputed.

Jean Guy Eugene Raymond Delaire was a French orthodontist known for developing the Delair Facemask or reverse headgear. This facemask is used to treat children who have maxillary retrognathism and mandibular prognathism.

Open bite is a type of orthodontic malocclusion which has been estimated to occur in 0.6% of the people in the United States. This type of malocclusion has no vertical overlap or contact between the anterior incisors. The term "open bite" was coined by Carevelli in 1842 as a distinct classification of malocclusion. Different authors have described the open bite in a variety of ways. Some authors have suggested that open bite often arises when overbite is less than the usual amount. Additionally, others have contended that open bite is identified by end-on incisal relationships. Lastly, some researchers have stated that a lack of incisal contact must be present to diagnose an open bite.

<span class="mw-page-title-main">Alveolar cleft grafting</span>

Alveolar cleft grafting is a surgical procedure, used to repair the defect in the upper jaw that is associated with cleft lip and palate, where the bone defect is filled with bone or bone substitute, and any holes between the mouth and the nose are closed.

It is estimated that nearly 30% of the general population present with malocclusions that are in great need of orthodontic treatment. However, the term dentofacial deformity describes an array of dental and maxillo-mandibular abnormalities, often presenting with a malocclusion, which is not amenable to orthodontic treatment alone and definitive treatment needs surgical alignment of upper/lower jaws or both. Individuals with dentofacial deformities often present with lower quality of life and compromised functions with respect to breathing, swallowing, chewing, speech articulation, and lip closure/posture. It is estimated that about 5% of general population present with dentofacial deformities that are not amenable to orthodontic treatment only.

John Mew is a British orthodontist. He is the founder of orthotropics and mewing. Orthotropics is a form of oral posture training that claims to guide facial growth and is not supported by mainstream orthodontists. John Mew's son Michael Mew is also an orthodontist and has also practised and promoted the idea of orthotropics.

Andrew A.C. Heggie is an oral and maxillofacial surgeon at the Royal Children's Hospital in Melbourne, Australia. His primary interest has been the management of developmental skeletal facial deformity, including patients with cleft lip and palate, craniofacial microsomia and infants with micrognathism. His contribution to the treatment of infant upper airway obstruction for Pierre Robin sequence, using internal devices for jaw lengthening using distraction osteogenesis, has replaced the need for tracheostomy in this condition. In 2019, Heggie was awarded Member of the Order of Australia for significant service to medicine and dentistry in the field of oral and maxillofacial surgery.

<span class="mw-page-title-main">Mandibular setback surgery</span>

Mandibular setback surgery is a surgical procedure performed along the occlusal plane to prevent bite opening on the anterior or posterior teeth and retract the lower jaw for both functional and aesthetic effects in patients with mandibular prognathism. It is an orthodontic surgery that is a form of reconstructive plastic surgery. There are three main types of procedures for mandibular setback surgery: Bilateral Sagittal Split Osteotomy (BSSO), Intraoral Vertical Ramus Osteotomy (IVRO) and Extraoral Ramus Osteotomy (EVRO), depending on the magnitude of mandibular setback for each patient. Postoperative care aims to minimise postoperative complications, complications includes bite changes, relapse and nerve injury.

References

  1. ↑ Nugent, Karen (May 2011). "DrExam™ Part B MRCS OSCE Revision Guide Book 1 and Book 2MirandaBH AsaadK KaySP DrExam™ Part B MRCS OSCE Revision Guide Book 1: Applied Surgical Science & Critical Care, Anatomy & Surgical Pathology, Surgical Skills and Patient Safety 2010 Libri Faringdon, Oxfordshire 456 £29.99 9781907471056MirandaBH AsaadK KaySP DrExam™ Part B MRCS OSCE Revision Guide Book 2: Clinical Examination, Communication Skills & History Taking 2010 Libri Faringdon, Oxfordshire 264 £29.99 9781907471063". Annals of the Royal College of Surgeons of England. 93 (4): 331. doi:10.1308/rcsann.2011.93.4.331a. ISSN   0035-8843. PMC   3363102 .
  2. ↑ L., Obwegeser, Hugo (2010). Mandibular growth anomalies : terminology, aetiology, diagnosis, treatment. Springer. ISBN   9783642086557. OCLC   715364997.{{cite book}}: CS1 maint: multiple names: authors list (link)
  3. ↑ "Jaw Deformities | Riley Children's Health". www.rileychildrens.org. Retrieved 2018-10-24.
  4. 1 2 Baig MA (October 2004). "Surgical enhancement of facial beauty and its psychological significance". Annals of the Royal Australasian College of Dental Surgeons. 17: 64–7. PMID   16479858.
  5. 1 2 Palumbo B, Cassese R, Fusetti S, Tartaro GP (2006). "Psychological aspects of orthognathic treatment". Minerva Stomatologica. 55 (1–2): 33–42. PMID   16495871.
  6. 1 2 3 Stirling J, Latchford G, Morris DO, Kindelan J, Spencer RJ, Bekker HL (June 2007). "Elective orthognathic treatment decision making: a survey of patient reasons and experiences". Journal of Orthodontics. 34 (2): 113–27, discussion 111. doi:10.1179/146531207225022023. PMID   17545299. S2CID   22757730.
  7. 1 2 3 4 Zhou YH, Hägg U, Rabie AB (2001). "Concerns and motivations of skeletal Class III patients receiving orthodontic-surgical correction". The International Journal of Adult Orthodontics and Orthognathic Surgery. 16 (1): 7–17. PMID   11563399.
  8. 1 2 3 Modig M, Andersson L, Wårdh I (February 2006). "Patients' perception of improvement after orthognathic surgery: pilot study". The British Journal of Oral & Maxillofacial Surgery. 44 (1): 24–7. doi:10.1016/j.bjoms.2005.07.016. PMID   16162374.
  9. ↑ Williams AC, Shah H, Sandy JR, Travess HC (September 2005). "Patients' motivations for treatment and their experiences of orthodontic preparation for orthognathic surgery". Journal of Orthodontics. 32 (3): 191–202. doi:10.1179/146531205225021096. PMID   16170061. S2CID   72122231.
  10. ↑ Lee LW, Chen SH, Yu CC, Lo LJ, Lee SR, Chen YR (July 2007). "Stigma, body image, and quality of life in women seeking orthognathic surgery". Plastic and Reconstructive Surgery. 120 (1): 225–31. doi:10.1097/01.prs.0000264100.57630.c7. PMID   17572567. S2CID   34916955.
  11. ↑ Chen B, Zhang ZK, Wang X (2002). "Factors influencing postoperative satisfaction of orthognathic surgery patients". The International Journal of Adult Orthodontics and Orthognathic Surgery. 17 (3): 217–22. PMID   12353939.
  12. 1 2 3 4 Alanko OM, Svedström-Oristo AL, Tuomisto MT (September 2010). "Patients' perceptions of orthognathic treatment, well-being, and psychological or psychiatric status: a systematic review". Acta Odontologica Scandinavica. 68 (5): 249–60. doi:10.3109/00016357.2010.494618. PMID   20513168. S2CID   533332.
  13. ↑ Posnick, Jeffery C. (2014). Orthognathic surgery: Principles & practice. St. Louis, Missouri : Saunders. p. 61. ISBN   9781455726981.
  14. ↑ Pahkala RH, Kellokoski JK (August 2007). "Surgical-orthodontic treatment and patients' functional and psychosocial well-being". American Journal of Orthodontics and Dentofacial Orthopedics. 132 (2): 158–64. doi:10.1016/j.ajodo.2005.09.033. PMID   17693364.
  15. ↑ Barros Vde M, Seraidarian PI, Côrtes MI, de Paula LV (2009). "The impact of orofacial pain on the quality of life of patients with temporomandibular disorder". Journal of Orofacial Pain. 23 (1): 28–37. PMID   19264033.
  16. ↑ Rumsey N, Clarke A, White P, Wyn-Williams M, Garlick W (December 2004). "Altered body image: appearance-related concerns of people with visible disfigurement". Journal of Advanced Nursing. 48 (5): 443–53. doi:10.1111/j.1365-2648.2004.03227.x. PMID   15533082.
  17. 1 2 III., HUPP, JAMES R.. TUCKER, MYRON R.. ELLIS, EDWARD (2019). CONTEMPORARY ORAL AND MAXILLOFACIAL SURGERY. [S.l.]: MOSBY. ISBN   978-0323552219. OCLC   1030766831.{{cite book}}: CS1 maint: multiple names: authors list (link)
  18. 1 2 3 4 5 Coulthard, P; Horner, K; Sloan, P; Theaker, E (2013). Master dentistry: volume 1: oral and maxillofacial surgery, radiology, pathology and oral Medicine (3rd ed.). China: Churchill Livingstone. ISBN   9780702055577.
  19. 1 2 Thilander, Birgit (2017-05-17). Essential orthodontics. Bjerklin, Krister, 1946-, Bondemark, Lars, 1955- (First ed.). Hoboken, NJ. ISBN   9781119165699. OCLC   974796239.{{cite book}}: CS1 maint: location missing publisher (link)
  20. ↑ Kolokitha OE, Chatzistavrou E (January 2009). "A severe reaction to ni-containing orthodontic appliances". The Angle Orthodontist. 79 (1): 186–92. doi: 10.2319/111507-531.1 . PMID   19123714.
  21. ↑ "Contemporary Surgical Planning For Jaw Deformities | Houston Methodist". www.houstonmethodist.org. Retrieved 2018-10-25.
  22. ↑ A., Quereshy, Faisal (2016). Upper Facial Rejuvenation, An Issue of Atlas of the Oral and Maxillofacial Surgery Clinics of North America, E-Book. Philadelphia: Elsevier Health Sciences. ISBN   9780323462723. OCLC   1015859975.{{cite book}}: CS1 maint: multiple names: authors list (link)
  23. ↑ Roberts-Harry D, Sandy J (November 2003). "Orthodontics. Part 2: Patient assessment and examination I". British Dental Journal. 195 (9): 489–93. doi:10.1038/sj.bdj.4810659. PMID   14610554. S2CID   21291436.
  24. ↑ Peterson's principles of oral and maxillofacial surgery. Miloro, Michael., Ghali, G. E., Larsen, Peter E., Waite, Peter. (2nd. ed.). Hamilton, Ont.: B C Decker. 2004. ISBN   978-1550092349. OCLC   57186698.{{cite book}}: CS1 maint: others (link)
  25. ↑ Edler RJ (June 2001). "Background considerations to facial aesthetics". Journal of Orthodontics. 28 (2): 159–68. doi:10.1093/ortho/28.2.159. PMID   11395532. S2CID   9558137.
  26. ↑ Agrawal M, Agrawal JA, Nanjannawar L, Fulari S, Kagi V (July 2015). "Dentofacial Asymmetries: Challenging Diagnosis and Treatment Planning". Journal of International Oral Health. 7 (7): 128–31. PMC   4513767 . PMID   26229387.
  27. ↑ Eric, Whaites (2013). Essentials of dental radiography and radiology. Drage, Nicholas (Fifth ed.). Edinburgh. ISBN   9780702045998. OCLC   854310114.{{cite book}}: CS1 maint: location missing publisher (link)
  28. ↑ Cunningham SJ, Johal A (February 2015). "Orthognathic correction of dento-facial discrepancies". British Dental Journal. 218 (3): 167–75. doi:10.1038/sj.bdj.2015.49. PMID   25686434. S2CID   20684660.
  29. ↑ "Micrognathia".
  30. 1 2 3 Oral and maxillofacial surgery : an objective-based textbook. Pedlar, Jonathan., Frame, John W. (2nd ed.). Edinburgh: Elsevier/Churchill Livingstone. 2007. ISBN   9780443100734. OCLC   698080410.{{cite book}}: CS1 maint: others (link)
  31. 1 2 3 Rajendran, Arya; Sivapathasundharam, B. (2014-02-10). Shafer's textbook of oral pathology. Rajendran, Arya,, Sundaram, Shivapatha (Seventh ed.). New Delhi, India. ISBN   9788131238004. OCLC   882243380.{{cite book}}: CS1 maint: location missing publisher (link)
  32. ↑ Mitchell, Laura (2013-01-24). An introduction to orthodontics. Littlewood, Simon J.,, Nelson-Moon, Zararna,, Dyer, Fiona (Fourth ed.). Oxford, United Kingdom. ISBN   9780199594719. OCLC   812070091.{{cite book}}: CS1 maint: location missing publisher (link)
  33. ↑ Crispian., Scully (2010). Medical problems in dentistry (6th ed.). Edinburgh: Churchill Livingstone. ISBN   9780702030574. OCLC   465366420.
  34. ↑ "Laterognathia | Dr. Madsen". Dr. Madsen. 2015-12-01. Retrieved 2018-10-25.
  35. ↑ Diéguez-Pérez M, de Nova-García MJ, Mourelle-Martínez MR, González-Aranda C (September 2017). "The influence of crossbite in early development of mandibular bone asymmetries in paediatric patients". Journal of Clinical and Experimental Dentistry. 9 (9): e1115–e1120. doi:10.4317/jced.54110. PMC   5650214 . PMID   29075414.
  36. ↑ O'Byrn BL, Sadowsky C, Schneider B, BeGole EA (April 1995). "An evaluation of mandibular asymmetry in adults with unilateral posterior crossbite". American Journal of Orthodontics and Dentofacial Orthopedics. 107 (4): 394–400. doi:10.1016/s0889-5406(95)70092-7. PMID   7709904.
  37. ↑ García Y, Sánchez JM, Gómez Rodríguez CL, Romero Flores J (September 2017). "Surgical Management of Laterognathia in Orthofacial Surgery". Journal of Maxillofacial and Oral Surgery. 16 (3): 365–373. doi:10.1007/s12663-015-0870-6. PMC   5493542 . PMID   28717296.
  38. ↑ Gateno, Jaime; Alfi, David; Xia, James J.; Teichgraeber, John F. (December 2015). "A Geometric Classification of Jaw Deformities". Journal of Oral and Maxillofacial Surgery. 73 (12 0): S26–S31. doi:10.1016/j.joms.2015.05.019. ISSN   0278-2391. PMC   4666701 . PMID   26608152.
  39. ↑ Gateno, Jaime; Alfi, David; Xia, James J.; Teichgraeber, John F. (December 2015). "A Geometric Classification of Jaw Deformities". Journal of Oral and Maxillofacial Surgery. 73 (12 Suppl): S26–31. doi:10.1016/j.joms.2015.05.019. ISSN   1531-5053. PMC   4666701 . PMID   26608152.
  40. ↑ Mizoguchi, Itaru; Toriya, Naoko; Nakao, Yuya (2013-11-01). "Growth of the mandible and biological characteristics of the mandibular condylar cartilage". Japanese Dental Science Review. 49 (4): 139–150. doi: 10.1016/j.jdsr.2013.07.004 . ISSN   1882-7616.
  41. 1 2 3 4 Ayoub, Ashraf; Khambay, Balvinder; Benington, Philip; Green, Lyndia; Moos, Khursheed; Walker, Fraser, eds. (2013-12-20). Handbook of Orthognathic Treatment. doi:10.1002/9781118751695. ISBN   9781118751695. S2CID   73948896.
  42. 1 2 3 Handbook of orthognathic treatment : a team approach. Ayoub, Ashraf. Hoboken: Wiley. 2013. ISBN   9781118751695. OCLC   861559590.{{cite book}}: CS1 maint: others (link)
  43. ↑ Gateno J, Alfi D, Xia JJ, Teichgraeber JF (December 2015). "A Geometric Classification of Jaw Deformities". Journal of Oral and Maxillofacial Surgery. 73 (12 Suppl): S26–31. doi:10.1016/j.joms.2015.05.019. PMC   4666701 . PMID   26608152.
  44. ↑ "Classification of Jaw Deformities". Huston Methodist. Archived from the original on 2018-10-24. Retrieved 2018-10-24.
  45. ↑ "Contemporary Surgical Planning For Jaw Deformities | Houston Methodist". www.houstonmethodist.org. Retrieved 2018-10-24.
  46. 1 2 3 4 5 6 7 8 9 10 11 "Facial and palatal development" (PDF).
  47. 1 2 3 "Facts about Cleft Lip and Cleft Palate". 2017-06-27.
  48. 1 2 3 4 Yuan X, He X, Zhang X, Liu C, Wang C, Qiu L, Pu W, Fu Y (March 2017). "Comparative Study of Folic Acid and α-Naphthoflavone on Reducing TCDD-Induced Cleft Palate in Fetal Mice". The Cleft Palate-Craniofacial Journal. 54 (2): 216–222. doi: 10.1597/15-211 . PMID   27018527.
  49. 1 2 3 Graf D, Malik Z, Hayano S, Mishina Y (February 2016). "Common mechanisms in development and disease: BMP signaling in craniofacial development". Cytokine & Growth Factor Reviews. 27: 129–39. doi:10.1016/j.cytogfr.2015.11.004. PMC   4753105 . PMID   26747371.
  50. 1 2 3 "Folic Acid May Prevent Cleft Lip and Palate". National Institutes of Health (NIH). 2015-09-21. Retrieved 2018-10-24.
  51. 1 2 3 4 Robinson RC, Holm RL (July 2010). "Orthognathic surgery for patients with maxillofacial deformities". AORN Journal. 92 (1): 28–49, quiz 50–2. doi:10.1016/j.aorn.2009.12.030. PMID   20619771.
  52. ↑ Khechoyan, David (2013). "Orthognathic Surgery: General Considerations". Seminars in Plastic Surgery. 27 (3): 133–136. doi:10.1055/s-0033-1357109. PMC   3805731 . PMID   24872758.
  53. 1 2 3 "Orthognathic surgery | Cambridge University Hospitals". www.cuh.nhs.uk. Retrieved 2018-10-24.
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