[Music] hello everybody and welcome to the periodontal series by dr teeth i'm dr sneha your parentology tutor so today's video will be in two parts in the first part we'll be discussing about trauma from occlusion and in the second part we'll be discussing about the pathologic tooth migration so first let's talk about trauma from occlusion otherwise also called as the tfo now let's discuss what exactly is occlusion so occlusion is the relationship between the occlusal surfaces of maxillary and mandibular teeth when they are in contact so if we see the picture right here this is the occlusal surface of the maxillary and mandibular teeth and they and when they fall in contact with each other it is termed as occlusion so normally when they fall in contact with each other there are certain forces that are generated so we know about the biting forces or these are otherwise called as the occlusal forces so these forces are usually first transmitted to the alveolar bone which are later dispersed to the basal bone of the maxilla and the mandible so here if you can see these occlusal forces first go towards the alveolar bone and then towards the basal bone of the maxilla and the mandible now there is something called as the adaptive capacity of the periodontium so when certain forces are applied onto the tooth surface when a certain degree of forces fall onto the tooth surface then the periodontium has the ability to adapt itself so it has a certain threshold to withstand the forces which are acting on it now in certain cases if the amount of forces exceed the adaptive capacity of the periodontism then periodontal injury will occur first let's understand the various factors on which the adaptive capacity of periodontium depends upon so the first factor we'll be talking about is the magnitude now when the occlusal forces is increased then there is a thickening of the periodontal ligament which takes place and there is increase in the number and the width of the pdl fibers so this is the first adaptive capacity of the periodontium to increase in the magnitude of forces and second is there is an increase in the density of the alveolar bone so these are the changes that happen in the periodontism if there is increased magnitude of occlusal forces now if there is a change in the direction of occlusal forces there is reorientation of the stress and strain that happens so the principal fibers of the periodontal ligament will rearrange itself so as to best accommodate the occlusal forces so here we can see that there is certain rearrangement which takes place now this rearrangement can occur either due to axial forces or due to lateral forces or due to forces of torque that is the rotational forces that act on the tooth third let's talk about the duration now it is seen that a constant pressure which is applied on the tooth it it it is more injurious uh to the bone because it leads to bone resorption as compared to the intermittent forces that are applied onto the tooth so we uh so in case of orthodontic forces there are intermittent forces that are applied onto the tooth because of which we see areas of bone formation as well as bone resorption that occurs so remember constant forces is more injurious to the tooth as compared to the intermittent forces last talking about frequency so more the frequency of forces which are applicable onto the tooth the more injurious it is for the periodontium so if you frequently apply forces onto the tooth then obviously the periodontism will undergo destruction or injury now let's talk about the concept of trauma from occlusion so glickman defined trauma from occlusion as when the occlusal forces exceed the adaptive capacity of the tissue tissue injury results so this means that if there is a tooth structure and if forces are applied onto the tooth structure the periodontium will try and adapt itself to these forces but after a certain threshold even the periodontism will give up and it results in injury and this injury is termed as trauma from occlusion so the synonyms of trauma from occlusion is also called as occlusal trauma chromatogenic occlusion periodontal trauma overload and traumatizing occlusion coming on to the classification of tfo now trauma from occlusion can be classified based upon the onset and duration into acute and chronic trauma and based upon its cause it can be classified into either primary secondary or combined trauma from occlusion so first let's talk about the acute tfo so in acute tfo it results because of an abrupt change in the occlusion forces such as a one which is produced when there is biting on a hard object so even atrogenic forces such as a faulty restoration or faulty prosthesis can cause an acute trauma so suddenly the tooth will encounter heavy forces that are applied on it and this causes acute trauma to the periodontium coming on to the chronic trauma from occlusion as a result of gradual changes which are produced in the periodontism for example tooth wear or drifting movements extrusions or other parafunctional habits there can be trauma that can occur to the tissues so this falls under chronic trauma from occlusion so here the tooth is slowly exposed to certain occlusal forces which on a long duration can cause periodontal injury now coming on to the classification based upon the cause so here first we have the primary trauma from occlusion so in this case the tissue reaction which is elicited around the tooth with normal height of the periodontium so if abnormal forces are applied onto the tooth with normal height of the periodontism then on a long run this can then either on an acute or a chronic basis this periodontium can undergo injury so this falls under primary trauma from occlusion it can result due to high fillings faulty restorations fixed and removable prosthesis which are altered or large forces on the abutments or the opposing teeth can cause primary trauma from occlusion the point to remember here is the height of the periodontium is normal coming on to the secondary trauma from occlusion now in this situation the periodontium is already reduced so there is presence of attachment loss and in this particular case if of occlusal force is applied now obviously because the periodontium is already reduced in height it further can lead to periodontal injury so this falls under secondary trauma from occlusion remember here the periodontium is already compromised and the occlusal forces which are applied are not heavy forces they are just normal forces which are applied coming on to the combined trauma from occlusion now in this particular scenario abnormal heavy occlusal forces are applied to teeth to teeth where already the periodontium is compromised so here both the situations are occurring even the occlusal forces are altered and even the periodontal support is inadequate so this leads to trauma from occlusion so quickly let's revise the primary secondary and tertiary trauma from occlusion so in primary the periodontium is healthy but there are abnormal forces or heavy forces which are applied onto the tooth in secondary trauma from occlusion there are normal forces of occlusion being applied to a tissue which is already compromised whereas in combined abnormal forces of occlusion is applied to a tissue which is already compromised so this is the most dangerous scenario so next let's talk about the role of trauma from occlusion in periodontal disease now many studies have been conducted and it has been seen that constant trauma which is produced onto the tooth which results in periodontal injury further predisposes uh this particular tooth to undergo loss of attachment and lead to periodontal disease so here we have two concepts that we need to understand the first theory was put about by glickman and it's also called as the glickman's concept it was given somewhere between 1965 and 67 and here glickman claimed that the pathway of spread of plaque associated gingival lesion can be changed if forces of abundant magnitude are acting on the teeth harboring the sub-gingival plaque so what does this exactly mean so it means that if a tooth is present with already presence of the sub-gingival plaque then obviously it will lead to some kind of gingivitis and periodontal destruction but if this particular tooth in addition to the plaque if it is also exposed to the abnormal occlusal forces then there is a alteration in the pathway of spread of inflammation that occurs so he stated that in normal scenario when there is only plaque present it leads to horizontal bone defects and supra bone pockets whereas if there is plaque along with trauma onto the tooth it leads to angular bone defects and infra bony pockets so basically glickman gave two zones he gave the zone of irritation and he gave the zone of co-destruction so basically the zone of irritation includes the marginal and the interdental papilla and it is affected only by the plaque and the microorganisms which are present in the plaque so according to glickman in this plaque associated lesion where there is no trauma that is occurring where there is no occlusal forces that are acting the pathway of spread of inflammation is from the marginal gingiva it directly first affects the alveolar bone and later on it goes into the periodontal ligament space so this is the pathway of spread of inflammation in case of teeth with only presence of microorganisms and plaque so here we see mostly horizontal bone loss and supra bony pockets whereas in the zone of core destruction so this mainly involves the periodontal ligament the pdl it involves the root cementum and it involves the alveolar bone and here a pycleat is demarcated by the transeptal fibers so the tissue in this zone becomes a seat of lesion by trauma from occlusion so there is abnormal forces which are acting on this particular teeth and here the spread of inflammation is directly towards the periodontal ligament so as you can see there is spread of inflammation which occurs into the periodontal ligament following which it goes into the alveolar bone so here we see more or less angular bone defects with infra bony pockets so remember uh in case of only presence of plaque there is presence of horizontal bone defects with supra bone pockets and in case of areas of co destruction that is plaque along with the occlusal forces it leads to vertical bone defects or angular bone defects along with infra bony pockets now this concept was not really supported by warehog so warehog did his independent studies and he found that angular defects and infra bony pockets also occurred in periodontal cases which are not affected by trauma so in other words he actually refuted the concept of glickman which he gave refuted the concept of glickmann and the whole concept of zone of irritation and co-destruction and he basically concluded that angular defects occurs when the sub-gingival plaque of one tooth reaches a more apical level than the neighboring tooth so if you have two teeth right here so here we have two neighboring teeth and if there is plaque which is present on this particular teeth and there is no plaque present on this then there is a angular defect which is formed so this is the alveolar bone and this bone forms a angular defect if there is presence of plaque on one teeth and there is no presence of plaque on the neighboring teeth so this concept was given by warehog it was also supported by other authors like prichard now let's talk about the signs and symptoms of trauma from occlusion so we have certain signs and symptoms which we can evaluate clinically so these are basically mobility so the tooth becomes progressively more mobile there is pain on chewing and percussion fremitus test is positive now what exactly is fremitis test so fremitus test basically helps to measure the vibratory patterns of the tooth when it when they are placed in contact with each other so what we do is we take a finger and place it along the teeth and along the gingiva so our finger is partially present on the gingiva and partially present on the tooth structure and we ask the patient to bite repeatedly and we try and feel or observe the vibrations associated with the teeth so if we feel the vibrations then we say that the primitive test is positive and there is trauma from occlusion the next uh signs and symptoms is occlusal prematurities and discriminant discrepancies there are presence of where facets tooth migration we will be talking about pathologic tooth migration in the second half of the video there can be presence of chipped or fractured tooth and thermal sensitivity is usually positive coming on to the radiographic signs so we can see increased width of periodontal ligament space there is thickening of the lamina dura there is presence of vertical and angular bone loss along with radiolucencies in the furcation areas so remember one thing in case of trauma from occlusion there is presence of vertical or angular bone loss with no pocket formation so this is the classical sign which we have to look for when we are judging trauma from occlusion coming on to histologic changes that can be seen now histologic changes can be put into three major categories we can see the stage of injury see the stage two which is of repair and stage three is of remodeling so let's discuss these stages in detail so in the stage of injury the tooth is exposed to the excessive forces of occlusion and the periodontium is unable to withstand these forces so hence what the periodontium does it it tries to distribute the forces and there is changes in the pdl and the alveolar bone that we see now depending upon the intensity of forces the tissues would react differently so so this so in the first scenario this is the normal scenario wherein there is normal occlusal forces that are acting on the tooth so as you can see here the pulp the dentine the cementum the pdl and the alveolar bone they are all quite normal both in the tension side as well as in the pressure side so it's quite balanced both in the tension as well as in the pressure sides whereas in case of slight forces in the tension side we can see elongation of the periodontal ligament fibers so as you can see here the periodontal fibers are elongated as well as there is deposition of bone that occurs and here the blood vessels they are basically less in number but they are all enlarged whereas on the pressure side you can see widening of the pdl so each fiber here is much more wide in in case of the pressure side and there is resorption of the alveolar bone on the pressure side along with that the number of blood vessels is increased but these but these blood vessels are reduced in size so the number is increased but the size is reduced now coming on to excessive forces or greater forces now towards the tension side there is further elongation of the periodontal ligament fibers which occur and this ultimately leads to the tearing of the periodontal ligament fibers so as you can see the integrity of periodontal ligament fibers is lost even the blood vessels undergo tearing and leads to hemorrhage and here even there is bone resorption that occurs so as there is no blood supply there is bone resorption that occurs now coming on to the pressure side during excessive forces it is seen that the pdl is further compressed in size and there is areas of hyalinization which develop so pdl ultimately undergoes necrosis and there are injuries to the fibroblasts as well now even the blood vessel undergoes breakdown there is uh formation of hemorrhagic spots and even here there is bone resorption that occurs so in case of excessive forces uh it leads to the classic periodontal case wherein there is bone resorption that is occurring on all the sides of the tooth which ultimately leads to tooth mobility coming on to the second stage that is stage of repair so when there are forces which are applied and the bone is resolved there is an attempt to reinforce the thinning of the trabeculae and this attempt to compensate for the lost bone is called as the buttressing bone formation so this is a very important reparative process that occurs during trauma from occlusion now buttressing bone formation can be of two types it can be central but dressing bone formation that usually occurs within the jaw whereas it can be peripheral but dressing bone formation this is mostly associated with the facial and the lingual alveolar plates now if the peripheral buttressing bone formation occurs in a shelf like thickening of the alveolar bone then this is called as the lipping the next step is the step of adaptive remodeling of the peridontium so if the repair process cannot keep in place with the destruction which is occurring from occlusion then the periodontium has no other way but to adapt and remodel itself so how does this happen this happens by the thickening of the pdl so there is formation of angular defects or vertical defects and ultimately there is increase in vascularity and ultimately because of these defects there is tooth mobility so these are the classical features of trauma from occlusion next let's talk about the pathologic tooth migration [Music] you