Ortho 1

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Today our lecture is " introduction to orthodontics " , he definition of orthodontics is: the branch of dentistry concerned with facial growth, development of the dentition & occlusion, & diagnosis, interception & treatment of occlusal anomalies .

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occlusal anomalies = abnormal occlusion = malocclusion . occlusal anomalies will be called from now on malocclusion. Orthodontics came from 3 words: Ortho : straight Dont : teeth Ics : every thing about So orthodontics means " every

thing about straight teeth ". *** orthopedics : 6b el3etham *** orthotics : straight religion ***othodontology : the science of straight teeth .

Before we start talking about malooclusion we have to realize what is normal occlusion "which is normal and which one is abnormal" Any occlusion fulfills these 6 keys of occlusion will be considered as normal occlusion: " keys, features, criteria that have been established by andrew's" o Correct molar relationship o Tight contact points o Normal teeth angulation o Normal teeth inclination o No rotation. o Flat curve of Spee. one criteria is missing we considered to have malooclusion" 1. Correct molar relationship; It’s the relation between upper & lower molars, there are three types of relationship; » Class I, the normal situation; in which the

2 mesio-buccal cusp of the upper 1st molar occludes on the buccal groove of the lower 1st molar. And this is the correct molar relationship .

» Class II, the mesio-buccal cusp of the upper 1st molar occludes anterior to the buccal groove of the lower 1st molar, ( the upper molars have moved forward ). In this case there is increased overjet.

» Class III, the mesio-buccal cusp of the upper 1st molar occludes posterior to the buccal groove of the 1st lower molar, (the lower jaw is protruded forward).

So if we have class II OR III molar relationship so definitely we have malocclusion , but if we have class I we have to look for the 5 keys .

2. Tight contact points: It means that there should be no spacing between teeth; either upper & lower or anterior & posterior. 3. Normal inclination of the teeth: The buccolingual tilting ot teeth. Look to slide no. 10 : Here the upper incisors are inclined outwards or labialy (protrusion)(proclination) Notice the spacing & malocclusion due to the abnormal position of these teeth. In the next slide- slide no. 11- the doctor showed us a case retrusion which the teeth are inclined inwards (lingually). 4. Normal teeth angulation: Angulation is also the tilting of the teeth but not buccolingualy , it is in mesio-distal direction. Look to slide no. 12 : here the central incisors are tilted distally not at upright position although it is normaly inclined 5. No rotation; Rotation is the case in which either the mesial or the distal edge is outside the line of the arch." not mentioned by the dr "

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normal inclination , normal angulation , normal overjet & overbite, normal molar relationship but the lateral incisor it is rotated , so it is not ideal occlusion . 6. Flat curve of Spee; The curve of Spee is an imaginary curve connects the incisal tips of the incisors with the cusp tips of the posterior teeth _ It should be flat _. In slide no. 14 : the anterior teeth are much higher than the posterior teeth ana that is called " accentuated curve", which means increased curve of spee . Some case are opposite to this in which the anterior teeth lower than the posterior teeth , which called " rverse curve o spee ". In ideal occlusion; curve of spee should be flat or maximally should be just 1 mm distance between the cusp of molars and the incisal edge of incisors . Now… **how often do we have an ideal occlusion ? Rarely we have a person with ideal occlusion , 96 % of the people have some sort of malocclusion

SO should every maloclussion be corrected or there are certain cases that we have to correct orthodontically? NO , there are indications for orthodontic treatment.

Indications for orthodontic treatment: o Esthetic criteria; most of the cases that are orthodontically treated are of esthetic causes, the patient comes and does not like his teeth appearance . sometimes there is something we call " internal motivation "; the patient himself doesn’t like his teeth. And there is something we call " external motivation" not the patient himself but maybe his parent or more commonly his wife!! There is a interesting study reveals that a lot of school teachers consider the students with nice teeth & occlusion to be smarter than students who have malocclusions. So it's important because there is something called " a psychological aspect of

4 dental appearance" people who have teeth that they don’t like tend to be shy and not have a good personality like people with straight teeth. o Functional & health reasons; **Caries & periodontal diseases… Irregular teeth are more susceptible to caries & dental problems as they are more difficult to clean, BUT this is not always true . In slides no 18 : the patient has has malocclusion with a very healthy gum and caries free… so The most important factor in determining the oral hygiene or periodontal status is the individual motivation & willingness, not if the teeth are aligned or not aligned . The other study compare between the peridontal status & orthodontics treatment : no difference between the periodontal status of treated and untreated subjects

SO periodontal disease isn’t caused by malocclusion , so to

treat malocclusion just purely to prevent caries or periodontal disease is not justified any more. **Traumatic occlusion: (2 exampes ; anterior cross bite & deep impinging bite) It’s some form of occlusion that if there is no periodontal disease there is no damage but if there is periodontal disease the rate of damage as a result of periodontal disease much much more increased . in this case we should treat it . Look to slide no. 22 There is a picture of teeth with general periodontal problem all over the dentition, but if you look at the lower central incisor you can see root recession this is because of the anterior cross bite that lead to traumatic occlusion so much more damaged to periodontal condition. Anterior crossbite means that the lower incisor bites in front of the upper

5 incisor" and called reversed overjet ". • In normal overjet upper incisors cover the lower incisors. • And in this case we should treat it even the patient is happy with appearance. • Deep Impinging bite : slide no. 23 In normal situation the lower incisor should occlude in the cingulum of upper incisor, but in this case the lower incisor bites on the palatal gum of upper incisors.if there is any inflammation of the palatal gum – peridontitis- the rate of damage will be much more and may cause recession . so we should treat it even the patient doesn’t have any complain becoz he may suffer from peridontitis -due to malocclusion- in the future . In these two cases (i.e., anterior crossbite & impinging bite we have to treat malocclusion in

order to prevent (or treat) any periodontal disorders. ***Craniomandibular disorders; These disorders are characterized usually by clicking and pain of TMJ . Malocclusion lead to abnormal bite so increased stress on the joint so worsens the condition. But later on it was proved otherwise; upon researches, it was proved that there

is no interrelation between malocclusion & TMJ disorders, or between orthodontic treatment & TMJ Disorders. So if the patient came to you with TMJ clicking & say to him I will fix ur malocclusion and release this click , it is not correct practice . So TMJ disorder is not related to malocclussiom Except for one thing which

6 lateral displacemet (we have is the

two types of displacements: anterior & lateral displacement. In case of lateral displacement the patient doesn’t occlude in the normal centeric position so every time he want to close his mouth (teeth) he will shift in the mandible laterally & usuallay to the left ). In this situation every time the patient is biting his teeth together he puts a little bit of more stress on TMJ and that can result in TMJ disfunction but not in every patient , so to treat malocclusion just to prevent TMJ disfunction or craniomandibular disorder is not a correct practice except in lateral displacement . So, TMJ disorders as a reason for the orthodontic treatment (treating malocclusion) is only indicated in the case of lateral displacement. o Functional reasons:

Here we will talk about mastication & speech The doctor showed us a picture for a patient with open bite_ slide no. 26; that is while the posterior teeth are in occlusion the anterior teeth are separated by a gap . You know that in order to speek the letter "S" you should have a specific separation between upper and lower incisors , so do you think that people with such malocclusion can speek the letter "S" normally or there will be something called lisp? Lisp is unable to speak the letter "S" , so they say "sh" instead of "s" Really you can see lisping in people with normal occlusion and lisping in people with anterior open bite , so it is NOT straight relationship between open bite and malocclusion . Now if the patient is lisping and has such malocclusion "open bite" , could this

7 lisping be as result of open bite? The answer is it might be , But you can't be 100% sure that if u treat the open bite that lisping will disappear , but we can give a choice to treat the open bite and that will improve the speak but it is not definite . The second thing is mastication , can this patient eat? You may expect that this patient is underweight but the fact is that he can eat, even he might be overweight… Its difficult to understand how do they eat… but really they just do ( but they can't eat seeds ) . And in this slide the patient complain was mainly esthetics . Now to treat malocclusion we have variety types of orthodontics treatment :  REMOVABLE orthodontics ; this type can be but and taken by the patient .  FIXED orthodontics ; can't be taken by the

patient ( brackets fixed on teeth ).  Orthodontics SURGERY done by surgeon .  FUNCTIONAL orthodontics . There is something to remember , that there is one thing is missing in the 6 keys that should be present in ideal occlusion but it is not mentioned : That is normal overjet and normal overbite , you can't have normal occlusion without normal overjet and normal overbite but it is not mentioned there , so does that mean it is not important ? No , what we can get from not mentioning overbite & overjet if we have the 6 keys of normal occlusion automatically we should have normal overjet and normal overbite , so they are consequence of the 6 keys of normal occlusion .

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Done by : zain smadi