Presentation on theme: "Oregon Dental Assistants Association"— Presentation transcript:
1Oregon Dental Assistants Association Occlusion & Facial Profileswhere is your clue?
2Oregon Dental Assistants Association Disclaimer All diagrams are courtesy of the following websites:dhonline.chattanoogastate.eduquizlet.com/ /skeletal-and-occlusal-classifications-oral anatomy-flash-cardsDentistry/Fall 2012
3Oregon Dental Assistants Association Prepared by:Sheri Billetter CDA, EFDA, MADAA BSThere are 39 slides to view. For credits refer to the exam and answer sheet for instructions
4Centric OcclusionThe relationship of the occlusal surfaces of one arch to those of the opposing arch.posterior teeth are closed in a relaxed normal position.anterior teeth have light contact.each person has their own individual centric occlusion.
5Angles Classification of Occlusion Dr. Edward Angle developed classifications for occlusion in 1890.he based his finding on the maxillary molar.it is important to remember that the mesiobuccal cusp of the maxillary 1st molar is the key to occlusion.exactly how does it interdigitate (“fit”) with the mandibular 1st molar?
6Angle’s Classification of Occlusion Class I – Normalalso known as neutro-occlusionthe MB cusp of maxillary 1st molar rests in the MB groove of mandibular 1st molar.
7Class ILook where mesiobuccal cusp of the maxillary 1st molar is located in comparison to the mandibular molar. Also look where the cuspids line up.
8Angle’s Classification of Occlusion Class II - Division 1Distal Occlusion - Bucky Beaver appearance.maxillary incisors tip outward from crowding.MB cusp of the maxillary 1st molar is forward on the MB cusp of the mandibular 1st molar.
9Class IINotice the location of the MB cusp of the maxillary 1st molar.
10Angle’s Classification of Occlusion Class II - Division 2Distal Occlusion - Bucky Beaver crowded.maxillary laterals protrude (tip facially)centrals retrude (tip lingually)MB cusp of the maxillary 1st molar is forward of the MB cusp of the mandibular 1st molar.
11Class II Division 2Notice how far forward the MB cusp of the maxillary 1st molar is. Also the cuspid relationship and crowding in the anterior.
12Angle’s Classification of Occlusion Class IIIAlso known as Mesial OcclusionJay Leno, Carol Burnett - protruded jaw.lower jaw appears longer - may have a bulldog appearance.maxillary incisors are “inside” mandibular incisors when jaws are closed.MB cusp of the maxillary 1st molar is posterior of the MB cusp of the mandibular 1st molar.
13Class IIILocation of the MB cusp of the maxillary 1st molar is distal on mandible. Cuspids and centrals are out of proper alignment.A Bulldog appearance is common.
14Types of Occlusion Ideal Occlusion RARE - Seldom Occurs there is a complete harmonious balance in the relationship of the teeth and other structures.all 32 teeth are present .all 138 occlusal contacts are in a specific pattern.uses the 1st molar relationship.maxillary anteriors (slightly) overlap the mandibular anteriors by 1/3.
15Types of Occlusion Normal Occlusion variations are minimal. functional stability of alignment and occlusion are maintained.1st molar relationship is the key.molar relationship the same as ideal occlusion.
16Types of Malocclusion What is malocclusion? any deviation from the ideal.can be minor, moderate or severe.may involve several teeth .can include jaw position.1st molar relationship is not always involved.
17Types of Malocclusion Openbite there is an existing space between the mandibular and maxillary teeth.may be anterior openbite.may be posterior openbite.may be unilateral (one side).or bilateral (both sides).
19Types of Malocclusion Overbite very deep vertical overlap - incisal edges of maxillary incisors extend far over the mandibular central incisors - can extend to the gingiva in severe cases.maxillary incisors are over the mandibular incisors far more than the 1/3 overlap.
21Types of Malocclusion Overjet there is a horizontal overlap creating a protrusion or space.between the labial surface of the mandibular incisors and the lingual surface of the maxillary incisors.
22Types of MalocclusionSevere Overjetand posterior crossbite
23Types of Malocclusion Crossbite teeth are positioned to the facial, buccal or lingual in contrast to its antagonist (opposing tooth).can be maxillary or mandibular teeth.Can be anterior or posterior.
24Malocclusion - Anterior Crossbite Anterior crossbite before and after correction.
25Malocclusion - Posterior Crossbite Unilateral Posterior Crossbite - only on one side.
29Types of Malocclusion End to End occurs in the molar areas there is no interdigitation of cusps or fossas -interdigitation is a natural fitting together.a cross bite or pre-crossbite condition can exist.
30Malocclusiona malocclusion or deviation can be genetic or created by habits or muscular dysfunction such as:thumbsucking or reverse swallowingmalocclusion classification depends on: the intensity, duration, how often it happens and the age it began.
31Facial ProfilesFacial profiles are based on an imaginary line from the forehead, through the ala of the nose and to the chin.Mesiognathic - considered a normal profile.Prognathic the mandible protrudes outward.Retrognathic - the mandible retrudes, is small or under developed.
33Deviations in Tooth Position Torsoversiona tooth may be rotated ie: buccal wall may face the lingual.Infraversiontooth is not completely erupted.Supraversionsuper erupted (over erupted).Transversiontooth is in the wrong place in the arch.
34Form and Function Curve of Spee a curvature formed by the maxillary and mandibular arches in occlusion.curvature of the occlusal plane from the posterior to the anterior.
36Form and Function Curve of Spee Mandibular Arch forms a slight curve inwardconcave (like the inside of a bowl)Maxillary Archforms a slight curve outwardconvex (like the outside of a bowl)
37Form and Function Curve of Wilson cross arch curvature of the posterior occlusal planeextends from the tip of the right molaracross the arch to the tip of the left molarfrom the left to the right across the arch
39Form and FunctionFunctions of the Curve of Spee and the Curve of Wilsonaccounts for strength and efficiency in chewing and the stability of teeth.aids in defining occlusion.aids in denture construction.balances the arches for orthodontics.