· web viewideally 75–100% of the maxillary incisor should be shown when smiling but this also...

Clinical examination and diagnosis. الجوني. عصام د.................................................................................................................................

Clinical examination and diagnosis

Dr. Issam Aljorani (BDS, MSc. Ortho.)

the term diagnosis is defined as the identification of a disease by careful investigation of its symptoms and history. While not a true disease per se, malocclusions are the "disease" processes of orthodontics and the central focus of orthodontic diagnoses.Successful orthodontic treatment begins with the correct diagnosis, which involves patient interview, examination and the collection of appropriate records. At the end of this process, the orthodontist should have assimilated a comprehensive database for each patient, from which the appropriate treatment plan can be formulated.The clinical examination includes an extra- and intra oral analysis of morphology and function. Often, the clinical examination has to be supplemented with further analyses using extra- and intra oral photographs, study casts (model analysis) and radiographs. The results from the interview, clinical examination and the supplementary analyses will constitute a solid basis for a comprehensive orthodontic diagnosis, which in turn forms a cornerstone for the treatment plan.

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"What is the patient's chief complaint?" This question is the basis of the anamnesis. At a minimum, the treatment plan should aim to address this important fundamental component of the patient's initial screening. The clinician is responsible for accurately understanding and addressing the chief complaint. Some patients will have very specific goals for treatment while others will provide more generalized expectations. Clear communication is the key to understanding a patient's objectives.Medical historyAs with all aspects of dentistry, oral problems cannot be treated in isolation of the rest of the body. A clear understanding of a patient’s medical problems and how this can affect potential orthodontic treatment is vital.

Medical Conditions to be Considered in Orthodontic TreatmentAllergies Allergic reactionAsthma Root resorption Coagulation disorders Bleeding riskDiabetes Periodontal diseaseepilepsy Gingival hypertrophy (medication)Heart valve conditions EndocarditisHigh blood presser patient taking calcium habit breaker

Gingival hyperplasia secondary tomedications

HIV Periodontal disease, opportunisticinfections

Leukemia Mucositis, oral infectionsOsteoporosis Bisphosphonate related ONJ

delayed tooth movementPhysical or mental handicap Gingivitis, relapse (muscle

Hyperactivity or hypooe1ivily)Rheumatiod arthritis TMJ degenerationTransplant patient Gingival hyperplasia related to

immunosuppressant drugsXerostomia Caries

Dental historyThe patient should be asked about their previous dental experience. This will provide an idea of their attitude towards dental health, what treatment they have had experienced previously and how this may affect their compliance with orthodontic treatment.Extraoral examinationAssessment of the patient should begin with an examination of the facial features

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because orthodontic treatment can impact on the soft tissues of the face. Although a number of absolute measurements can be taken, a comprehensive facial assessment involves looking at the balance and harmony between component parts of the face and noting any areas of disharmonyNatural head postureNatural head posture (NHP) is the position that the patient naturally carries their head and is therefore the most relevant for assessing skeletal relationships and facial deformity. The patient is asked to sit upright and look straight ahead to a point at eye level in the middle distance. This can be a point on the wall in front of them, or a mirror so that they look into their own eyes. Frontal viewThe frontal view of the face should be assessed vertically and transversely, with attention being paid to the presence of any asymmetry. In addition, the relationship of the lips within the face is examined in detail.Vertical relationshipVertically the face is split into thirds, with these dimensions being approximately equidistant. Any discrepancy in this rule of thirds will give an indication of disharmony within the facial proportions and where this lies. Of particular relevance is an increase or decrease in the lower face height. The lower third of the face can be further subdivided into thirds, with the upper lip falling into the upper third and the lower lip into the lower two-thirds.

Lip relationshipThe relationship of the lips should also be evaluated from the frontal view • Competent lips are together at rest;• Potentially competent lips are apart at rest, but this is due to a physical obstruction, such as the lower lip resting behind the upper incisors; and• Incompetent lips are apart at rest and require excessive muscular activity to obtain a lip seal.Lip incompetence is common in preadolescent children and competence

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increases with age due to vertical growth of the soft tissues, especially in males.

Incisor show at restIn adolescents and young adults, 3–4 mm of the maxillary incisor should be displayed at rest. In general, females tend to show more upper incisor than males, with the amount of incisor show reducing with age in both sexes. An increased incisor show is usually due to an increase in anterior maxillary dentoalveolar height or vertical maxillary excess. Occasionally it is due to a short upper lip. The average upper lip length is 22 mm in adult males and 20 mm in females. Incisor show on smilingIdeally 75–100% of the maxillary incisor should be shown when smiling but this also reduces with age. Some gingival display is acceptable, although excessive show or a ‘gummy smile’ is considered unattractive.

Smile aestheticsMost patients seek orthodontic treatment to improve their smile, so it is important to recognize the various components of a smile that will improve the aesthetics A normal smile should show the following:• The whole height of the upper incisors should be visible on full smiling, with only the interproximal gingivae visible. This smile line is usually 1–2 mm higher in females.• The upper incisor edges should run parallel to the lower lip (smile arc)• The upper incisors should be close to, but not touching, the lower lip• The gingival margins of the anterior teeth are important if they are visible in the smile. The margins of the central incisors and canines should be approximately level, with the lateral incisors lying 1 mm more incisally than the canines and central incisors• The width of the smile should be such that buccal corridors should be visible, but minimal. The buccal corridor is the space between the angle of the mouth and the buccal surfaces of the most distal visible tooth.• There should be a symmetrical dental arrangement• The upper dental midline should be coincident to the middle of the face.

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Transverse relationship and symmetryThe transverse proportions of the face should divide approximately into fifths. No face is truly symmetrical; however, any significant facial asymmetry and the level at which it occurs should be noted. This can be done by assessing the patient from the front and also from behind and above, looking down the face. The relative position of each dental midline to the relevant dental base should be recorded. Asymmetries of the lower face are particularly common in class III malocclusion with mandibular prognathism.

Profile viewThe facial profile should be assessed anteroposteriorly and vertically. Anteroposterior relationship an assessment should be made of the skeletal dental base relationship between the upper and lower jaws in the anteroposterior plane. This can be achieved by mentally dropping a true vertical line down from the bridge of the nose (often called the zero meridian). The upper lip should rest on or slightly in front of this line and the chin slightly behind. Alternatively, the dental bases can be palpated labially.• In a normal or skeletal class I relationship, the upper jaw should be approximately 2–4 mm in front of the lower.• In a skeletal class II relationship the lower jaw is greater than 4 mm behind the upper;and• In a skeletal class III relationship the lower jaw is less than 2 mm behind the upper.An assessment can also be made of the angle between the middle and lower third of the face, with the profile being described

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as:• Normal or straight;• Convex; or• Concave

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Nasolabial angle and lip protrusionThe nasolabial angle is formed between the upper lip and base of the nose (columella) and should be between 90° and 110°. It gives an indication of upper lip drape in relation to the upper incisor position. A high or obtuse nasolabial angle implies a retrusive upper lip, whilst a low or acute angle is associated with lip protrusion.

Vertical relationshipThe face can also be divided into thirds as described earlier and direct measurements made of the facial heights . The angle of the lower border of the mandible to the cranium should also be assessed. This can be done by placing an index finger along the lower border and approximating where this line points. If it points to the base of the skull around the occipital region, the angle is considered average. If it points below this, the angle is reduced, whilst above it the angle is increased. This usually, but not always, correlates with measurementsmade of the anterior face height.

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Intraoral examinationThe intraoral examination is concerned primarily with the teeth in each dental arch, in both isolation and occlusion.Dental healthThe teeth present clinically should be noted and an assessment made of the general dental condition, including the presence of untreated caries, existing restorations and the standard of oral hygiene.Excellent oral hygiene is essential for orthodontic treatment otherwise there is a high risk of decalcification. Treatment should not begin until a patient can demonstrate they can consistently maintain high levels of oral hygiene.We are particularly interested in detecting:• caries• areas of hypomineralisation• effects of previous trauma• tooth wear• teeth of abnormal size or shape• existing restorations which may change the way we bond to the tooth, as well determine our choice of extractions if space is requiredDental arches• Presence of crowding or spacing in the labial and buccal segments, Crowding represents a discrepancy between the size of the dental arch and the size of the teeth. It is important that the degree of crowding is assessed as accurately as possible as this will in part determine the anchorage requirement and need for extraction. In general, crowding is usually described as mild (0 – 4 mm), moderate (5 – 8 mm) or severe (greater than 9 mm).

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• Tooth rotations, described in relation to the most displaced aspect of the coronal edge and the line of the dental arch;• Tooth displacement in a labial or lingual direction in relation to the line of the arch;• Position and inclination of the labial segment relative to the dental base. These are described as being average, proclined or retroclined. • Presence and position of the maxillary canines, which should be palpable buccally from the age of 10 years;• Angulation of erupted canines, which should be recorded as mesial, upright or distal and Incisor relationshipThe incisor relationship is described using the British Standards Classification, but also needs to be supplemented with a description of the overjet and overbite.Buccal segmentsThe buccal segment relationship is described using the Angle classification. The molar and canine relationships should also be noted.OverjetThe overjet should be measured from the labial surface of the most prominent maxillary incisor to the labial surface of the mandibular incisors. The normal range is 2–4 mm. If there is a reverse overjet, as can occur in a class III incisor relationship, this is also measured and given a negative value.OverbiteThe normal range is for the maxillary incisors to overlap the mandibular by 2–4 mm vertically, or one-third to one-half of their crown height. Overbite is described as:• Increased if the maxillary incisors overlap the mandibular incisor crowns vertically by greater than one-half of the lower incisor crown height;• Decreased if the maxillary incisors overlap the mandibular incisors by less than one third of the lower incisor crown height. If there is no vertical overlap between the anterior teeth, this is described as an anterior open bite and a measurement should

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be made of the incisor separation;• Complete if there is contact between incisors, or the incisors and opposing mucosa; and• Incomplete if there is no contact between incisors, or the incisors and opposingmucosa.

Anterior crossbiteTeeth in anterior crossbite should be noted along with the presence and size of any displacement of the mandible that may occur when closing from the retruded contact position into the intercuspal position. An anterior crossbite with displacement can cause labial gingival recession and mobility of the lower incisors in traumatic occlusion, which if present, should be recorded.Posterior crossbiteThe transverse relationship of the dental arches is described in occlusion. Crossbites are described in relation to the arch or teeth that are displaced most from their ideal position, whether they are localized or affect the whole segment of the dentition and if they occur unilaterally or bilaterally:• A mandibular buccal crossbite exists when the buccal cusps of the mandibular dentition occlude buccally to the buccal cusps of the maxillary dentition. If it isprimarily due to a narrow maxillary arch it should be described as a maxillary lingual crossbite;• A mandibular lingual crossbite exists when the buccal cusps of the mandibular dentition occlude lingually to the palatal cusps of the maxillary dentition (this can also be referred to as a scissors bite). If is primarily due to wide maxillary arch, it should be described as a maxillary buccal crossbite.• A unilateral crossbite affects one side of the dental arch; and• A bilateral crossbite affects both sides of the dental arch.

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CentrelinesMaxillary and mandibular dental centrelines are assessed in relation to the facial midline and to each other. Displacement of a centreline can be due to:• Asymmetric dental crowding;• Buccal crossbite with a mandibular displacement on closing; and• Skeletal asymmetry of the jaws.

Orthodontic recordsClinical orthodontic records are used primarily for diagnosis, monitoring of growth and development, and are a medico-legal requirement. They provide an accurate representation of the patient prior to orthodontic treatment, demonstrate treatment progress and allow communication between orthodontists, other healthcare professionals and the patient. Records also play an important role in research and clinical audit. It is essential that accurate clinical records are taken before commencing orthodontic treatment.Study modelsImpressions showing all the erupted teeth, full depth of the palate and good soft tissue extension are needed. These can be taken in alginate for study models and poured in dental stone. Orthodontic models should be trimmed with the occlusal plane parallel to the bases, so the teeth are in occlusion when the models are placed on their back. The bases are also trimmed symmetrically so the arch form can be assessed and they are neat enough to be used for demonstration to the patient. Accurate digital study casts are also now available, which have the advantages of occupying no physical storage space and having no deterioration over time, enabling indefinite storage.

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Clinical photographsGood clinical photographs form an essential part of the clinical record. They provide a baseline record of the presenting malocclusion, and are important in treatment planning especially in relation to facial and dental aesthetics, allow monitoring of treatment progress and are useful for teaching. The following views should be taken:• Intraoral, taken with the occlusal plane horizontal:• Frontal occlusion;• Buccal occlusion (left and right);• Maxillary dentition; and• Mandibular dentition.• Extraoral, taken against neutral background in natural head posture:• Full facial frontal;• Full facial frontal smiling;• Facial three-quarters; and• Facial profile.

RadiographsRadiographs are usually required prior to orthodontic treatment to assess:• Presence or absence of permanent teeth;

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• Root morphology of permanent teeth;• Presence and extent of dental disease;• Presence of supernumerary teeth;• Position of ectopic teeth; and• Relationship of the dentition to the dental bases and their relationship to thecranial base.Routine radiographs used in orthodontic assessmentA number of radiographic views are routinely used by the orthodontist.

Occlusal radiographsOcclusal radiographs are taken with the film placed on the occlusal plane and can offer greater detail in the labial segments. They are particularly useful in the maxillary arch, for assessing root form of the incisors, the presence of midline supernumerary teeth and canine position, either alone or in combination with additional views using parallax.

Dental panoramic tomograph (orthopantograph OPG)Panoramic radiography or, more specifically, the dental panoramic tomograph provides a useful screen for the presence or absence, position and general health of the teeth and their supporting structures with a relatively low-radiation dose. Because these radiographs are sectional in nature, they can be unclear in some regions, particularly the labial segments where variations in the depth of the anterior

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focal trough for different patients can influence clarity of the incisors.

Cephalometric lateral skull radiographCone-beam computed tomography (CBCT)it is three-dimensional diagnostic tool and particularly useful for the diagnosis of impacted and ectopic teeth, allowing their accurate localization and the visualization of any associated resorption.

Optical laser scanning and stereo photogrammetryOther less invasive techniques for generating three-dimensional images of the facial soft tissues have also been developed. Optical laser scanning utilizes a laser beam, which

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is captured by a video camera at a set distance from the laser and produces a three dimensional image. More recently, stereo photogrammetry has been developed, which involves taking multiple pictures of the facial region simultaneously. This allows the creation of a three-dimensional model image. These techniques are now being used to study facial growth and soft tissue changes in normal populations and investigate the effects of orthodontic and surgical treatment.

You can

download this lecture from E-MOODLE website http://elearn.uobabylon.edu.iq

references An introduction to orthodontics, Laura Mitchell, fourth edition, 2014Essential orthodontics, Birgit Thilander, first edition, 2018Handbook of orthodontics, Martyn and Andrew, second edition, 2016.

Dr. Issam M. Abdullah AljoraniBDS, MSc. Ortho.

University of Babylon, college of [email protected]

2017

Optical laser scanning

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http://elearn.uobabylon.edu.iq/

· web viewideally 75–100% of the maxillary incisor should be shown when smiling but this also...

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