DENTAL IMPLANT PART3-PLACING A DENTAL IMPLANT

• Before placing a dental implant, following things should be taken into consideration-

1. Identification of vital structures like inferior alveolar nerve,mental foramen & maxillary sinus
2. Dimension,shape,density of bone
3. Medical history of patient
4. OPG and other diagnostic aids like CT scan
5. Sinus lift or dental bone graft might be needed before placing implant

• First an incision is made at the surgical site and a flap is raised.
• After that using a sequence of drills a pilot hole is bored in the bone,while doing that take proper care of the adjacent vital structures.
• Keep spraying fresh saline over the bone to prevent osteonecrosis,due to heat released during the drilling.
• Implant body is fixed in the pilot hole and flap is sutured back.
• Generally osseointegration takes 3 months in the lower jaw and 6 months in the upper jaw.
• Instruction to be followed by the patient during the period of osseointegration-

1. Not to give any kind of straining to the dental implant.
2. Avoid deleterious habits like smoking 
3. Don't spit, suck on straws. This can dislodge blood clots and slow healing.
4. Eat only soft food to avoid injury to gums
5. Don't try to clean the implant area for the next one to two weeks, but clean the rest of your mouth normally.Can use mouth wash

• After3/6 months latter when osseointegration has taken place,the implant body is again exposed after giving an incision and than a healing cap is placed. It maintains the space so that the gum heals correctly around the implant.
•  Two or three weeks after the second surgery place the abutment and crown on the implant fixture after removing the healing cap.
• In some cases it can be decided to restore the dental implants immediately after placing them in the process of the dental implant surgery. This dental implants procedure is known as immediate loading and it's duration is very short - the patient can walk home the same day of the surgery with their newly restored teeth.

WHY ITS IMPORTANT TO VISIT DENTIST REGULARLY FOR SCALING (Cleaning up of teeth in Lehman language)

Hello guys,
I am writing this post for the common people of the society,to create an  awareness  regarding the importance of making regular visit to dentists and asking them for full mouth scaling.
To start with the topic lets first discuss what is the basic structure of our gingiva (gum).

In the picture you can see that the pink color object is our gum tissue and below it there is bone socket with tooth root inside it.You can also see that between the bone and the tooth root  there are horizontal lines which are called as periodontal ligaments(just like ropes are used to hold a tent).Gum tissues,Bone and periodontal ligaments together hold the tooth in place.This is very raw understanding of the basic structure of gingiva.
One should understand that once the gingiva/supporting bone/periodontal ligaments get destroyed,tooth looses its support and finally exfoliates.
When we eat food,Food particles get entrapped in the space present between two teeth.Now our mouth has got many types microbes(pathogens).Which start getting attached to these food particles.They satrt multiplying there and increases the mass.This mass is called as dental plaque.After some period of time this dental plaque starts getting calcified and forms dental calculus (Tartar)
As this dental calculus grows in size following changes occur-

• Dental plaque or calculus invades the gingiva,along the tooth root.At this stage Gingiva starts to show the signs of inflammation(a clinical term,for a Lehman it can be taken as an infection).This can be seen as severe pain, reddening of gingiva and bleeding from gums(acute form of inflammation) or no pain,just reddening or bluish coloration of gingiva(chronic form of inflammation).
• As the calculus growth increases the the toxins liberated by the bacteria and normal body reactions start to destruct the bone and periodontal ligaments.From this stage the tooth starts to become mobile.If left untreated sooner or latter tooth exfoliate.This is called as periodontitis.

 The animation below gives a better idea of the pathological process-In this animation growing gray color material is the dental calculus/tartar and u can see that as its growing supporting structures of tooth are receding and finally tooth gets devoid of all support and finally exfoliates.
As the supporting structures are lost,tooth root starts to get expose.This can lead to sensitivity to both hot and cold, pain on chewing ,foul odor like symptoms.
During scaling,dentist removes all dental plaque and calculus adhering to the tooth.But gingivitis and periodontitis can only be cured when there is full support from the patient as well and he keeps a proper oral hygiene.
Some points which patient should follow for keeping good oral health-

• Eat food that contains less sugary stuff and which is less sticky.Eat more fibrous food.
• Avoid acidic beverages like cola and soda.
• Gargle properly after every meal.
• Brush at least twice a day.Once in day time after taking breakfast and once at night before going to bed
• Visit your dentist every six months or when u suffer from any kind of oral or dental malfunction.

Beside dental plaque and calculus there are some conditions and diseases in which the gum tissues and supporting structures become more vulnerable to destruction and it becomes important for a person to visit regularly to a dentist-

• Pregnant Ladies-In pregnant ladies gingiva becomes more reactive to dental plaque and calculus.Gingiva shows enlargement in size.
• Puberty-This is also a systemic condition in which there is excessive overgrowth of gingiva and it shows exaggerated response to plaque or calculus
• People taking following medicines should consult there dentist if they found any abnormality related to there gingiva-

1. Calcium Channel Blockers like nifedipine (given to heart patients or hypertensive patients[high B.P.] )
2. Anti convulsant drugs like phenytoin (given to epileptic patients)
3. Immunosupressive drugs like cyclosporines
4. Antidepressants 

• Diabetic patients-In diabetes,there is excessive loss of periodontal ligaments and bone.
• Patients going for Radiotherapy or Chemotherapy -Patients who are going under chemotherapy or radio therapy should consult there dentist prior to the therapy.
• Leukemia(blood cancer patients in Lehman terms)
• If you are breathing from mouth more often you should consult your dentist because mouth brathers become more prone to gingivitis
• HIV patients-HIV patients should make a regular visit to a dental clinic as there immunity is weak which make them suspectable to many oral diseases.
• Patients having Cardiac disorders or who have gone under heart surgeries should meet there dentist regularly and should maintain a proper oral hygiene.

Drug induced gingival enlargement

Pregnancy induced Gingival enlargement(pregnancy Tumour)

I guess from now on you guys will visit your dentist regularly for good oral health..after all nobody wants an artificial smile...:)

CAUSES OF PERIODONTITIS

Periodontitis can be due to two reasons-

• Gingivitis
• Trauma from Occlusion

THE PRIMARY STAGES OF PERIODONTAL DISEASE

	Healthy tissues No bleeding or puffy gums, pockets all measure to a normal 3mm or less.
	Periodontitis I (Gingivitis) Bleeding gums when measured, puffy in appearance and pockets no greater than 3mm. No damage to the supporting bone in this stage.
	Periodontitis II Bleeding and puffy gums that measure slightly more than normal at up to 5mm.
	Periodontitis III Bleeding and swollen gums with pockets that will measure up to 6mm and more. Recession beginning to appear.

DENTAL IMPLANT PART2 - PARTS OF DENTAL IMPLANTS

Dental Implant consists of following parts-

PARTS OF DENTAL IMPLANT

HEALING SCREW

• Implant body/fixture-This is the part of the implant which is placed during the first stage of the implant surgery, and which provides the anchor or foundation for the restoration. This part is fixed in the jaw bone, and on this the abutment is screwed in the next stage of the surgery. 
• Healing screw-This is a part of the implant which isn't permanently placed, but is used during the healing phase when the soft tissue over the implant body is being healed. The healing screw facilitates the suturing of the soft tissue, and it also prevents the growth of tissue over the edge of the implant.
• Healing caps-These are the dome shaped caps placed over the healing screws to project through the soft tissue into the oral cavity, and they range from 2-10 mm in length. They prevent the overgrowth of the tissues over the implant body, and even guide for the placement of the permanent restoration after the second stage of the surgery.
• Abutment-An abutment provides support for the crown.It is fixed into the Implant body and latter on over it the crown is given.It also has got an abutment screw.

MI paste

MI Paste is a one-of-a-kind product that restores minerals and helps you produce saliva. It is the only dental product with RECALDENT™ (CPP-ACP), a special milk-derived protein that is a breakthrough in oral health care in helping to remineralize teeth.

MI Paste and MI Paste Plus with RECALDENT™ (CPP-ACP):
• Strengthens your teeth with tooth-replenishing calcium and phosphate
• Releases vital minerals into your mouth when and where they are needed
• Produces a saliva-like environment that maintains normal acid levels and healthy teeth
• RECALDENT™ CPP-ACP is milk derived with lactose content less than 0.01%.*
• Helps condition, protect and rebuild your tooth surfaces
• Is a water-based, sugar-free crème that comes in five delicious flavors

MI Paste with RECALDENT (CPP-ACP) fortifies your teeth to keep your smile vibrant for a lifetime.

* Casein phosphopeptides are derived from milk casein. Do not use this material on patients with a proven or suspected milk protein allergy and/or with a sensitivity or allergy to benzoate preservatives.

The MI Paste™ and MI Paste Plus™ Family

MI Paste is the only product for professional use containing the active ingredient RECALDENT™ (CPP-ACP), a special milk-derived phosphopeptide that binds calcium and phosphate to tooth surfaces, plaque and surrounding soft tissue. MI Paste is a water-based, sugar-free créme that is applied directly to the tooth surface or oral cavity. MI Paste with RECALDENT™ (CPP-ACP) restores the oral mineral imbalances that cause demineralization by replacing minerals while improving saliva flow and fluoride uptake as well as soothing sensitive surfaces - making it an ideal treatment for:

• Reversing tooth sensitivity and restoring enamel gloss after whitening procedures
• Relieving dry mouth caused by certain medications
• Reducing high oral acid levels from excessive soft drink consumption
• Reversing tooth sensitivity before and after professional cleaning
• Reducing high oral acid levels - sometimes a consequence of pregnancy
• Buffering acids produced by bacteria and plaque
• Regular conditioning during orthodontics, during and after bands or brackets have been removed, to prevent and reverse white spot lesions
• Providing a topical coating for patients suffering from erosion, caries and conditions arising from xerostomia

Use MI Paste™ -For white spot lesions; For desensitizing;During and/or after orthodontics; For medically compromised patients; For salivary deficiency/dry mouth; For patients with acidic oral environments; For erosion and gastric reflux; For patients with poor plaque control; For high-caries risk patients; To provide extra protection for teeth

MI Paste Plus offers the same benefits of MI Paste , but is enhanced with a patented form of fluoride (900ppm) to further promote remineralization and protect teeth from caries development. Since the fluoride acts in conjunction with RECALDENT™ (CPP-ACP), it is more effective than fluoride alone. MI Paste Plus is the only product that gives you the correct bio-available ratio of 5-calcium, 3-phosphate and 1-fluoride, which provides the ultimate enamel strengthening.

Specially designed for patients at high risk for dental caries and dental erosion, MI Paste Plus enhances mineral uptake without encouraging the formation of calculus. MI Paste Plus is safe and easy to use both in office and at home, and can even be claimed on a patient's insurance as fluoride treatment. It is also recommended for night use in patients with marked salivary dysfunction (dry mouth) due to medications, systemic illnesses, or salivary gland disease, because of the enhanced risk of mineral loss from dental caries or dental erosion.

ENAMEL MATRIX DERIVATIVE

• Contain amelogenin protein (found in enamel matrix)
• Can be used to reconstruct cementum,periodontal ligaments and alveolar bone during reconstructive surgeries.
• EMDOGAIN-commercial material available in market contain amelogenin protein.obtaine from dental follicles of piglet
• It is hypothesized that the application of these proteins onto root surfaces results in adsorption onto the root surface, and the promotion of cementoblast differentiation, cementum formation, and periodontal ligament and alveolar bone formation for true periodontal regeneration. 
• Till date technology hasn't been able to regenerate enamel.We have been able to get enamel matrix by using amelogenin protein but the basic problem encountered is that we are not able to control the mineralization  of this matrix.Research is going on.
• Nanospheres are the lastest advancement in dentistry.The assembly of amelogenin protein into nanospheres is postulated to be a key factor in the stability of enamel extracellular matrix framework, which provides the scaffolding for the initial enamel apatite crystals to nucleate and grow.

Reconstructive periodontal surgeries

DENTAL IMPLANTS PART I

DEFINITION-Implant is something that replaces a natural tooth.
Implantation should be differentiated from other two terms-Replantation and Transplantation
Replantation-its the reinsertion of a tooth back into its socket after accidental or intentional removal from the socket.
Transplantaion-Its the insertion of body part from one site to another.
CLASSIFICATION OF DENTAL IMPLANTS-

1. ENDOSTEAL
2. SUBPERIOSTEAL
3. TRANSOSTEAL
4. EPITHELIAL IMPLANT

ENDOSTEAL IMPLANT-Its an implant that is directly placed into the bone like a natural teeth.
SUBPERIOSTEAL IMPLANT-In this a custom cast framework is placed directly beneath the periosteum,overlying the bony cortex.Its used in cases where there is excessive bone loss.
TRANSOSTEAL IMPLANT-It combines both subperiosteal and endosteal components.this implant passes through the full thickness of the alveolar bone.This type of implants are restricted to be used in anterior area of mandible and provide support for tissue borne overdentures.
EPITHELIAL IMPLANT-Inserted into oral mucosa.
Titanium is the most common material that is used for dental implants.Reasons behind this are-
*high heat resistance of titanium
*High strength of titanium
*Resistance to corrosion
*Biocomaptible


Various implant materials that have been used in the market till date are-

1. Ti-6Al-4V (most biocompatible)
2. CP Titanium (cp-commercially pure)
3. Ti-6Al-4V ELI (Extra low interstitial)
4. Stainless steel
5. Aluminium oxide
6. Zirconia

ATTACHMENT MECHANISM-Dental implants mostly get attached to the cortical bone by the process called as osseointegration.
Osseointegration is a process in which living bony tissues come under the direct connection of the implant surface without any intervening fibrous connective tissue,making it structural and functionally stable.
Implant surfaces can be of threaded,grooved,perforated,plasma sprayed or coated type.
MODIFICATIONS-Metallic implants can modified by following processes- 

1. PASSIVATION-Enhancment of the oxide layer to prevent the release of the metallic ions as a result of surface breakdown,this makes implant more biocompatible.
2. Anodization-In this current is passed through the implant.This adds oxide layer to the implant surface that is much more thicker as compared to the one produced by passivation.It helps to prevent corrosion of implant surface.
3. Surface texturing-Its a process of increasing surface roughness to aid in surface area for bone attachment.This can be attained by acid etching or by blasting with aluminium oxide or any other ceramic material.

BIOACTIVE/BIOCONDUCTIVE Materials-They are the variety of inorganic materials that can stimulate adhesion and bonding to bone.These materials can either be coated on implant surface or they can be plasma sprayed on implant surface. 
Calcium Hydroxyapatite(HA) and Tricalcium phosphate are two commonly used bioactive materials.
The major advantage of these coatings is that they stimulate the bone formation.
There are some disadvantages associated with bioactive materials,which are-
 *The long term stability of HA coated implants is still controversial.The interface between the HA and implant surface can be unstable
* Microorganisms can adhere to the HA surface leading to peri-implantitis  
Thus Bioactive coated implants to be used in cases where there is less bone available for implant placement. 
Clinical Success of an Implant-Criteria of Albrektsson et al

1. Implant must be immobile when tested clinically
2. no sign of periapical radiolucency
3. Vertical bone loss less than 0.2mm annually  following the implants's first year of service
4. absence of any signs of inflammation like pain,infection etc

Reference-Phillips 11TH Edition

SUBPERIOSTEAL IMPLANT

ENDOSTEAL IMPLANT

MYOFUNCTIONAL APPLIANCES

FORM follows FUNCTION
INTRODUCTION-

• Myofunctional Appliances-Removable or fixed orthodontic appliances which use forces generated by the stretching muscle,fascia and/or periodontium to alter skeletal and dental relationships.
• They are passive appliances.
• How they work-These appliances use the natural forces generated by the stretched muscles.The increased muscle activity act as a stimulus for mandibular growth.
• All functional appliances are made up of following components-

1. BITE PLANES
2. SHIELDS
3. WORKING BITE
4. WIRE COMPONENTS

• BITE PLANES- 

*Types- Anterior/Posterior
              Flat/Inclined

*Anterior Bite block are helpful in opening of bite.They cause selective eruption of                                                        posterior segment of teeth.They can also be used to cease the supra eruption of anteriors.They can also be used to tip the anteriors.

*Posterior Bite Block are helpful in correcting anterior cross bite cases as they lift the bite up and eliminates the hindrance caused by mandibular teeth in the growth of maxilla and maxillary incisors.

*Anterior Inclined planes can be used to give a guiding plane for the labio lingual eruption of incisors or bucco lingual deflection of molars.

• SHIELDS-Vestibular shields/oral screens/lip pads are important in eliminating the undesired muscular forces (Like that of cheeks,lips etc),that impede the growth of jaws and causes favorable forces to act on jaws that can add to there growth .

        Shield also stretches the muscles causes underlying periosteal pull,which in turn causes bone growth in     desired direction.

These shield can also be used to prohibit various oral habits like mouth breathing,thumb sucking etc.

•  WORKING BITE-All functional Appliances are Constructed to a Construction or working bite registration.This registration is the one which is desired by the dentist or which is said to be the perfect occlusion for the patient.

       Construction Bites are taken at a Vertical Dimension.For a vertical grower the vertical dimension of construction Bite is kept more and for a horizontal grower its kept less.

• Some Important Points- 

1. Myofunctional Appliances can only be used only in growing patients.
2. Myofunctional Appliances are most favorably used in cases of Class II div 1 cases,having retrognathic mandible.
3. An ideal case for functional appliances is the one which is devoid of gross irregularities like crowding,rotations etc.
4. Most functional appliances causes upper anteriors to tip palatally and lower anteriors to tip bucally
5. Functional appliances causes condylar growth in upward and backward direction,leading a downward and forward growth of mandible.
6. Myofunctional Appliances also remodel condylar fossa in forward and downward direction.
7. It should be remembered that as the lower jaw grows anteriorly,the lower posteriors move mesially and occlusaly ,leading to increase in lower anterior facial height.All myofunctional appliances causes an increase in lower anterior facial height.so they should be cautiously used in patients having excessive vertical dimensions,and if used they should be used after  giving posterior bite blocks that can control the vertical eruption of molars.
8. In the transverse direction,functional appliances can bring about expansion of jaws by incorporating screws
9. Most of the functional appliances need post treatment fixed appliance therapy for detailing occlusion.

• Types Of Myofunctional Appliances-

1. ACTIVATOR
2. BIONATOR
3. FRANKEL
4. HERBST 
5. JASPER JUMPER

DEEP BITE

DEFINITION- A condition of excessive overbite, where the vertical measurement between the maxillary and mandibular incisal margins is excessive when the mandible is brought into habitual or centric occlusion’. 
Since the crown length of the lower incisors significantly varies in individual, a notation of the overbite in percentage is more descriptive and desirable . When the teeth are brought into habitual or centric occlusion. Usually normal overbite is 2-3mm or 30% percent or 1/3 rd the clinical crown height of the mandibular incisors.
Deep bite (or deep overbite) is present when the mandibular incisors' occlusal edges occlude apical to the cingulum of the maxillary incisors.
This may be due to overeruption of either the maxillary or mandibular anteriors or due to infraocclusion of molars.
*Closed Bite-condition of excessive overbite, where the vertical measurement between the maxillary and mandibular incisal margins is excessive when the mandible brought into habitual or centric occlusion. Closed bite is excessive overbite resulting from loss of posterior teeth. It is rarely seen in young children, must not be confused with deep bite. Excessive overbite is most prevalent in the mixed dentition and is a self correcting transient malocclusion.
CLASSIFICATION- 

1. According to its origin;
   1. Dental deep bites (Simple).
   2. Skeletal deep bite (Complex).
2. According to functional classification;
   1. True deep bite.
   2. Pseudo deep bite.
3. Depending on the extent of deep bite
   1. incomplete over bite
   2. complete over bite

Dental deep bite- 

• localized to the teeth and alveolar processes.
•  Dental deep bites occur due to over-eruption of anteriors or infra-occlusion of molars. 
• The result may be labial version of the upper incisors and impingement of the lowers into the palatal mucosa. 
• In the mandibular dentition, it may manifest as a deep curve of Spee or a reverse curve of Spee in the maxillary dentition.

Skeletal deep bite-

• deep bite associated with basic skeletal features with which the alveolar process cannot cope.
• A skeletal type of overbite may be due either to malrelationship of alveolar bones and/or underlying mandibular or maxillary bones or to an overgrowth or undergrowth of one or more alveolar segments. 
• It occurs due to convergence of maxilla and mandible towards each other
• The dimished anterior vertical height of the face is also an important criterion for diagnosis of skeletal deep overbites. Facial height doesn't vary in case of dental deep bite.
• frequently associated with class II div 2 and occasionally with Class III.

True deep bite-

• This is caused by  infraocclusion of the posterior  segments ie..molars
• Seen in class II div II
• It is often the result of a lateral tongue posture of tongue thrust. The interposition of tongue prevents the eruption of the posterior teeth. It can also occur due to premature loss of posterior teeth
• These patients have near flat curve of spee.
• There is  a large interocclusal clearance

Pseudo deep bite-

• is caused by  overeruption of the anterior teeth  that already has normal eruption of the posterior segment teeth
• Seen in class II div I malocclusions
• It is the result  of overeruption of the incisors. Due to the presence of the increased overjet, the lower incisors to over-erupt until they meet the palatal mucosa.
• These patients hence exhibit an excessive curve of Spee
• The inter-occlusal clearance is usually normal or small as the molars are fully erupted.

Incomplete & complete deep bite- Incomplete over bite is an incisor relationship in which the lower incisors fail to occlude with either the upper incisors or the mucous of the palate when the teeth are occluded. Complete over bite on the other hand is a relationship in which the lower incisors contact the palatal surface of the upper incisors or the palatal tissue when the teeth are in centric occlusion.
ETIOLOGY-The etiology of deep overbite is a complex problem and may include one or more of the following;

1. Hereditary and may follow a genetic pattern or familial condition
2. Skeletal: 
   1. An overgrowth or undergrowth of one or more alveolar segments.
   2. An excess of growth of the ramus and posterior cranial base permits the mandible to rotate upward. Thus Long ramus and short body with decreased gonial angle is characterstic feature.
   3. Convergent upper and lower jaw bases 
   4. Horizontal growth pattern or forward rotation or anticlock wise rotation of the of the lower jaw.The four planes of the face (inraorbital ( FH Plane), palatal, occlusal, and mandibular) as seen from lateral roentgenograms are horizontal and nearly parallel to each other.
3. Dental:
   1. Loss and/or mesial tipping of posterior teeth. In other words diminished posterior dental height
   2. Early loss of teeth and lingual collapse of the anterior teeth
   3. Overeruption of the incisor teeth, infraocclusion of the buccal segment or a combination of both.
   4. Overbite may because or accentuated by an aberration in the tooth morphology.
   5. Periodontal disease. Bite may deepen if the posterior tooth drift mesially during the pathological migration and worsen the existing condition
   6. When the teeth are reduced in size and number, the dental arches oppose less resistance against mandibular closure.
4. Muscular: The posterior vertical chain of muscles (masseter, internal pterygoid, temporal) is strong and attached anteriorly on the mandible and stretches in nearly a straight line vertically. The molars are directly under the impact of the masticatory forces of this chain. When the posterior vertical chain of muscles is strong and anteriorly positioned, a greater depressive action is transmitted to the dentition
5. Habits:
   1. lateral Tongue thrust swallow
   2. Finger sucking,
   3. Lip sucking

Open Bite

INTRODUCTION-Open bite is a malocclusion that occurs in the vertical plane, characterized by lack of vertical overlap between the maxillary and Mandibular dentition. The anterior open bites particularly skeletal open bites are called as “stigmata of malocclusion”.
Openbites are easy to diagnose but difficult to retain.
CLASSIFICATION - Open bites can be: anterior or posterior
                                                         Skeletal or dental
                                                         Unilateral or bilateral
ANTERIOR OPEN BITE-
ETIOLOGY-Many potential etiologic factors are implicated as causes of open bite including heredity, unfavorable growth patterns, digit-sucking habits, tongue and orofacial muscle abnormal function, orofacial functional matrices and their interaction with the skeletal components , imbalances between jaw posture, occlusal and eruptive forces and head position.

1. Heredity with genetic disposition: Inherited factors such as increased tongue size, and abnormal skeletal size and growth pattern of the maxilla and mandible can also be responsible for open bite malocclusion.
2. Habits: The effect of habits on dentofacial structures is discussed in detail in the chapter of ‘Habits’.
   1. Prolonged thumb-sucking habit is one of the chief etiological factors of open bite. The posture of thumb positioning, the intensity, and the frequency of sucking, all have an influence on the nature and severity of the open bite.
   2. Tongue thrusting is also implicated for some cases of open bite. Tongue thrusting may develop as a complication of thumb sucking habit. Some times tongue thrusting develops as a compensatory mechanism for existing openbite. Thus whether chick comes first or egg is a matter of controversy.
   3. Nasopharyngeal airway obstruction and associated mouth breathing may also result in openbite
3. Skeletal 
   1. An overgrowth or undergrowth of one or more alveolar segments. In anterior openbites there is undergrowth of the anterior segment with excessive growth posterior alveolar portion. In posterior openbites there is undergrowth of the posterior alveolar segment .
   2. Increased anterior and decreased posterior facial height. The posterior face height (Sella -Gonion) and Anterior face height (Nasion –Menton ) are measured on lateral cephalogram with teeth in habitual occlusion to estimate growth directions according to recommendations of JARBAK(JARBAK RATIO). A ratio of less than 62 percent expresses vertical growth pattern and open bite tendency whereas a ratio of more than 65 percent increases the likelihood for horizontal vector and deep bite tendency .
   3. Vertical growth pattern or backward rotation or clock wise rotation of the of the lower jaw
   4. Anticlock wise rotation of the maxillary base.
   5. Divergent jaw bases
   6. Short ramus with long or short body and Increased gonial angle( articulare—gonian –menton )
4. Dental: When there is only dental and dentoalveolar involvement, there is predominance of environmental causes such as thumb or dummy sucking habits, mouth breathing, and tongue or lip thrusting in addition to some local factors such as tooth ankylosis and eruption disturbances that result from over eruption of the posterior teeth or under eruption of the anterior teeth. The periodontal breakdown of anterior teeth may also give rise to anterior openbites with flaring of teeth.

Features of skeletal anterior open bite

 The problem is related to the skeletal bases. A patient having a skeletal anterior open bite is characterized by the following

1. The patient often has a long and narrow face with marked convex profile. A patient with underlying skeletal class III bases may have concave profile.
   1. The patient may have a short upper lip with excessive maxillary incisor exposure
   2. Increase lower anterior facial height and decreased upper anterior facial height
   3. A steep mandibular plane angle( High angle). Thus the angle FMA is increased. There is clock wise rotation or backward rotation of the mandible with increased lower anterior facial height .
   4. Small mandibular body and ramus
   5. Divergent jaw bases 
   6. There is upward rotation of maxillary jaw base

The patient may have a narrow maxillary arch due to lowered tongue posture due to a habit.

Features of dental anterior open bite

Dental anterior open bites do not present with the skeletal complications mentioned above. The following are the features of dental open bite:

1. 1. Proclined upper anterior teeth.
   2. The upper and lower anteriors fail to overlap each other resulting in a mild open bite.
   3. The patient may have a narrow maxillary arch due to lowered tongue posture due to a habit.

POSTERIOR OPEN BITE-

Posterior open bite is a condition characterized by lack of contact between the posteriors when the teeth are in centric occlusion. It mostly occurs in a segment of the posterior teeth.

Causes of posterior open bite

There are two possible causes of posterior open bite:

1. Mechanical interference with eruption, either before or after the tooth emerges from the alveolar bone, or
2. Failure of the eruptive mechanism of the tooth so that the expected amount of eruption does not occur.

Mechanical interference with eruption may be caused by ankylosis of the tooth to the alveolar bone, which can occur spontaneously or as a result of trauma, or by obstacles in the path of the erupting tooth. Examples of such obstructions prior to emergence are supernumerary teeth and non resorbing deciduous tooth roots or alveolar bone. After the tooth emerges from the bone, pressure form soft tissues interposed between he teeth (cheek, tongue, finger) can be obstacles to eruption Ankylosed teeth are usually in infraocclussion and are said to be submerged.The most commonly submerged tooth is retained lower decidous second molar. The second possible cause of eruption failure is a disturbance of the eruption mechanism itself. These patients have no other recognizable disorder, and no mechanical interferences with eruption seem to exist. The condition may be the cause of posterior open-bite which does not respond to orthodontic treatment.

CEMENTAL TEAR

Definition- A small portion of cementum separated, either partially or completely, from the underlying dentin of the root as a result of occlusive force or due to ageing wear out.
Etiology-Heavy occlusive forces or age
Clinical Feature-

• Generally seen w.r.t anterior teeth
• Deep Periodontal pockets (up to 11mm)
• Angular bone loss
• Vital Pulp
• Periodontal pockets exist only in relation to a single tooth and otherwise the whole of the gingiva can be healthy with no deep pockets

Its must to differentiate cemental tears from peripaical/periodontal pathologies.Dentist should avoid unnecessary RCT.Xrays taken at different angulations and pulp vitality help to differentiate.

Occlusion

Angle's Class II Malocclusion

DEFINITION-Angles class II malocclusion is characterized by class II molar relation where the distobuccal cusp of upper first molar falls in the buccal groove of mandibular first molar.
CLASSIFICATION- Class II Div 1 & Class II Div 2
Angles class II malocclusion can be dental or it can be of skeletal origin.
Skeletal Features can include a prognathic maxilla or a retruded (hypoplastic) mandible or both.
CLASS II DIV 1 MALOCCLUSION-

• Its a condition exhibiting class II molar relationship along with proclined maxillary incisors.
• Increased over jet(due to protruded upper incisors)
• Convex profile(due to protruded upper incisors)
• Short hypo tonic upper lip(due to protruded upper incisors)
• Patient may place lower lip against palatal surface of upper incisors leading to lip trap
• Abnormal muscle activity  and lower tongue possition (abnormal buccinator and mentalis activity leading to constricted maxillae)
• Posterior Cross bite(due to constricted maxilla)
• Patient shows a normal path of closure for mandible

Class II div1 can again be classified depending on the lower facial height.
In class II div1 lower facial height can be found to get increased or it can be normal.
If its increased than there would be reduced overbite or mild open bite and if its normal than there would be pseudo deep bite.
Pseudo Deep bite-Due to proclined upper anterior,the lower anterior fail to make contact with the palatal surface of upper anterior.thus they are free to erupt leading to an increased overbite and excessive curve of spee.

CLASS II DIV2 MALOCCLUSION-

• The Class II div 2 malocclusion is a condition characterized by a class II molar relation with retroclined upper centrals that are overlapped by lateral incisors.
• Here the muscle activity seems to be normal and so is the maxillary arch
• Backward path of closure of mandible is seen (due to palatally tipped upper CI)
• Straight profile face

Class II div 2 are always cases of true deep bite.


Thus Class II div 1 can either show excess vertical growth or normal growth whereas Class II div 2 are always cases of horizontal growth.
HOW TO CHECK THAT WHETHER CLASS II MALOCCLUSION IS BECAUSE OF MAXILLARY PROGNATHISM OR MANDIBULAR RETROGNATHISM?
Visual treatment Objective-In this patient is asked to bring his mandible forward,if the patient's profile improve by this movement than the malocclusion is due to retrognathic mandible.and patient is an ideal candidate for myofunctional appliance therapy.(if he is meeting other requirements as well)