Written by : Dr. Urusa I Inamdar

Diagnostic radiograph of tooth used to estimate the working length by measuring the tooth from a stable occlusal reference point till radiographic apex

Subtract atleast 1 mm from this length as minor constriction is present short of the anatomic apex and compensation for radiographic image distortion.

This measurement is transferred to a diagnostic instrument with a silicon stop then placed in the root canal and working length radiograph is taken.

Now measure the difference between the end of the instrument and radiographic apex of the root , on the radiograph.

Tip of the instrument ends 0.5 mm – 1 mm from the radiographic root apex – working length established .

  • Short of the radiographic apex by more than 1.0 mm – then add this value to the earlier estimated length and adjust the stopper on diagnostic instrument accordingly.
  • Beyond the radiographic apex – reduce this value from the earlier estimated length and adjust the stopper on diagnostic instrument.

Retake the working length radiograph .

Weine’s modification:

  • If periapical bone resorption is evident in a radiograph , the working length should be reduced 1.5 mm short of the radiographic apex as the apical constriction would have been destroyed by the resorption .
  • If apical root resorption is seen , the working length is reduced to 2 mm short of the radiographic apex , in such an event , an apical stop is created short of the radiographic apex to prevent overinstrumentation and subsequent overfilling of the root canal .


  • Grossman’s Endodontic Practice (13th edition)
  • Dental notes


Written by : Dr. Urusa I Inamdar

Krasner and Rankow’s Laws of Access Opening

  • Law of centrality : The floor of the pulp chamber is always located in the center of the tooth at the level of the CEJ .
  • Law of concentricity : The walls of the pulp chamber are always concentric to the external surface of the tooth at the level of the CEJ .
  • Law of the CEJ : The distance from the external surface of the clinical crown to the wall of the pulp chamber is the same throughout the circumference of the tooth at the level of CEJ .
  • Law of symmetry 1 : Except for maxillary molars , the orifices of the canals are equidistant from a line drawn in a mesiodistal direction through the pulp chamber floor .
  • Law of symmetry 2 : Except for maxillary molars , the orifices of the canals lie on a line perpendicular to a line drawn in a mesiodistal direction across the center of the floor of the pulp chamber .
  • Law of color change : The color of the pulp chamber floor is always darker than the walls .
  • Law of orifices location 1 : The orifices of the root canals are always located at the junction of the walls and the floor .
  • Law of orifices location 2 : The orifices of the root canals are located at angles in the floor – wall junction .
  • Law of orifices location 3 : The orifices of the root canals are located at the terminus of the root developmental fusion lines .
Law of Centrality
Law of concentricity
Law of symmetry
Orifice location


  • Dental notes
  • Grossman’s Endodontic Practice (13th edition)
  • Google search


Written by : Dr. Urusa I Inamdar


Ribbon shaped or thin connecting structure between two root canals.

Kim et al. have classified the isthmus into following categories:

  • Type I : Faint communication between two canals.
  • Type II : Complete isthmus with a definite connection between two canals.
  • Type III : A complete but very short isthmus between two canals.
  • Type IV : Complete or incomplete isthmus between three or more canals.
  • Type V : Two or three canal openings without visible connections.

Apical Foramen:

In young , incompletely developed teeth , the apical foramen is funnel shaped , with the wider portion extending outward . The mouth of the funnel is filled with periodontal tissue , which is later replaced by dentin and cementum.

As the root develops , the apical foramen becomes narrower .

It is not necessary to shape , clean , or fill root canals to their anatomic apices , but rather to the cementodentinal junction , which usually lies within the canal just short of the apex .

The apical foramen is not always the most constricted portion of the root canal. Constrictions can and do occur before the extremity of the root ks reached. Apical constrictions are found 0.5-1.0 mm away from the root apex.

The apical foramen is not always located in the centre of the root apex . It may exit on the mesial , distal , labial or lingual surface of the root , usually slightly eccentrically.

In few cases , the apical foramen has been found as much as 2-3 mm away from the anatomic apex.

The root canal obturation should end approximately 0.5-1.0 mm short of the anatomic root apex .

Lateral canals and Accessory foramina:

The periodontal vessels curve around the root apex of a developing tooth and often become entrapped in Hertwig’s epithelial root sheath , resulting in the formation of lateral canals and accesory foramina during calcification .This phenomenon frequently occurs in the apical third of the root .

Lateral canals may also occur in the area of bifurcation or trifurcation of multirooted teeth.

With increasing age , the accesory foramina diminish in number because of calcification of their contained soft tissue.


  • Dental notes
  • Grossman’s Endodontic Practice

Root Canals

Written by : Dr. Urusa I Inamdar

It is the portion of the pulp cavity from the canal orifice to the apical foramen.

It is divided into 3 sections :

  • Coronal
  • Middle
  • Apical
  1. Accessory canals or lateral canals : lateral branching of the main root canal generally occurring in the apical third or furcation area of a root.
  2. Lateral canal : accessory canal that branches to the lateral surface of the root and may be visible on a radiograph.
  3. Apical foramen : aperture at or near the apex of a root through which the blood vessels and nerves of the pulp enter or leave the pulp cavity.
  4. Accessory foramina : openings of the accessory and lateral canals in the root surface.

A straight root canal extending the entire length of the root is uncommon. Either a constriction is present before the apex is reached or , as is often the case , a curvature is present.

The curvature may be :

  • A straight canal extending with minimal apical curvature.
  • A gradual curvature of the canal with a straight apical ending.
  • A gradual curvature of the entire canal.
  • A sharp curvature of the canal near the apex.

A curvature of about 20° in a narrow root canal may be difficult or even impossible to negotiate with endodontic instruments, whereas a curvature of even 30° may be negotiated if the root canal is wide.

Success in negotiating a narrow , curved canal depends on following :

  • Degree of curvature.
  • Size and constriction of the root canal.
  • Size and flexibility of the endodontic instrument blade.
  • Skill of the operator.

The various classification proposed are as follows :

  • Vertucci’s Classification:
  1. Type I : Single canal extends from the pulp chamber to the apex (1)
  2. Type II : Two separate canals leave the pulp chamber and join short of the apex to form one canal (2-1)
  3. Type III : One canal leaves the pulp chamber and divides into two in the root , the two then merge to exit as one canal (1-2-1)
  4. Type IV : Two separate distinct canals extend from the pulp chamber to the apex (2)
  5. Type V : One canal leaves the pulp chamber and divides short of the apex into two separate distinct canals with separate apical foramina (1-2)
  6. Type VI : Two separate canals leaves the pulp chamber , merge in the body of the root , and redivide short of the apex to exit as two distinct canals (2-1-2)
  7. Type VII : One canal leaves the pulp chamber, divides and then rejoins in the body of the root , and finally redivides into two distinct canals short of the apex (1-2-1-2)
  8. Type VIII : Three separate distinct canals extend from the pulp chamber to the apex (3)
  • Weine’s classification :
  1. Type I : Single canal from pulp chamber to apex
  2. Type II : Two canals leaving from the chamber and merging to form a single canal short of the apex
  3. Type III : Two separate and distinct canals from chamber to apex
  4. Type IV : One canal leaving the chamber and dividing into two separate and distinct canals
  • Classification based on canal cross – section:
  1. Round (circular)
  2. Oval
  3. Long oval
  4. Flattened (flat/ribbon)
  5. Irregular


  • Dental notes
  • Grossman’s Endodontic Practice (13th edition)

Pyrexia of Unknown Origin ( Part -2 )

Written by : Dr. Urusa I Inamdar

Clinical signs:

  • Fever from an infection often presents with night sweats and weight loss.
  • In a rheumatological cause patient present with:
  1. Arthralgia
  2. Myalgias
  3. Fatigue
  • In cancer patients, the presentation is more likely:
  1. Pain
  2. Lack of appetite

Physical examination – Infectious disease:

Physical findings with specific significance in patients:

Non imaging test for PUO:

Diagnostic imaging in patients with PUO:


In the majority of cases, treatment other than supportive care should not be commenced until a diagnosis is obtained. Early use of antipyretics or antimicrobial may delay diagnosis. The mortality rate for PUO is less than 10%.

If infective endocarditis is suspected, then the patient should be admitted to a hospital and empiric intravenous antibiotics should be commenced after three sets of blood cultures have been collected.

The recommended empiric regimen of infective endocarditis in Australia is gentamycin , benzylpenicillin and flucloxacillin; however this may vary with different patient factors and should be discussed with an infectious disease specialist.


  • Davidson’s- Principles and practice of medicine
  • Gsk – webevent console
  • Dental notes

Pyrexia of Unknown Origin ( Part -1 )

Written by - Dr.Urusa I Inamdar


  1. Fever higher than 38.3 c ( 101F ) on several occasions.
  2. Illness of more than 3 weeks duration.
  3. No diagnosis made after 1 week of inpatient investigation.

Common causes not be missed for Fever which is not subsiding after 1 week of treatment:

  • enteric fever
  • Tuberculosis
  • viral fever
  • Leptospirosis
  • Scrub typhus
  • urinary tract infection
  • intraabdominal abscess
  • hepatitis A and B

Common etiologies of Fever of Unknown Origin

  • Infections
  1. Miliary TB
  2. Enteric Fever
  3. Intraabdominal abscess
  4. TB meningitis
  5. Brucellosis
  6. EBV/CMV
  7. Complicated UTI
  • Neoplastic disorders
  1. Lymphoma
  2. Hepatoma/Liver metastasis
  3. Colon cancer
  4. Myeloproliferative disorders
  5. Renal cell carcinoma
  6. CNS tumors
  • Rheumatic /inflammatory disorders
  1. Still’s disease
  2. Temporal arteritis
  3. Rheumatic arthritis
  4. SLE
  5. Sarcoidosis
  6. Polyarticular gout
  7. Polymyalgia rheumatica
  • Miscellaneous
  1. Drug fever
  2. Alcoholic cirrhosis
  3. Sub-acue thyroiditis
  4. PTE
  5. Inflammatory bowel disease

Classification of Fever of Unknown Origin

  • Classic

duration of more than 3 weeks.

Evaluation of atleast 3 outpatient visits or 3 days on hospital.

  1. Infection
  2. Malignancy
  3. Collagen vascular disease
  • Nosocomial

patient hospitalized more than 24 hrs but no fever or incubating on admission.

Evaluation of atleast 3 days.

  1. Clostridium difficile enterocolitis
  2. Drug induced
  3. Pulmonary embolism
  4. Septic thrombophlebitis
  • Immune deficient

Neutrophil count less than 500 per mm3.

Evaluation of atleast 3 days.

  1. Opportunistic bacterial infection
  2. Aspergillosis, Candidiasis, Toxoplasmosis
  3. Herpes virus
  • HIV associated

Duration of more than 4 weeks for outpatients.

More than 3 days for inpatient.

HIV infection confirmed.

  • Cytomegalovirus
  • Mycobacterium
  • PCP


  • Gsk – webevent console
  • Dental notes
  • Davidson’s – Principles and practice of Medicine


Written by - Dr.Urusa I Inamdar

Also called as oral malodor.

” Halitosis may rank only behind dental caries and periodontal disease as the cause of the patients visit to the dentist.”



  • Poor oral hygiene
  1. Retention of odoriferous food particles on and between the teeth.
  2. Coated tongue.
  3. Artificial dentures.
  • Acute Necrotizing Ulcerative Gingivitis.
  • Pericoronitis.
  • Abscess.
  • Dehydration states.
  • Ulceration in the oral cavity.
  • Hyposalivation/Xerostomia.
  • Bone disease ( dry socket , Osteomyelitis , osteonecrosis and malignancy )
  • Smoker’s breath.
  • Healing oral wounds.
  • Chronic periodontitis with pocket formation.

Extraoral ( Conditions that can contribute to presence of oral malodor )

  • Sinusitis and other bacterial infections.
  • Dry nasal mucosa.
  • Blocked nose ( which can cause mouth breathing )
  • Tonsillitis/ tonsil stones.
  • Various carcinomas.
  • Infections of the respiratory tract ( bronchitis , pneumonia , bronchiectasis )
  • Alcoholic breath.
  • Uremic breath of kidney dysfunction.
  • Acetone odor of Diabetes.

It is important for the dental professional to eliminate systemic conditions that may be contributing to the presence of oral malodor.

The clinical assessment of oral malodor is either subjective or objective . Subjective assessment is based on smelling the exhaled air of the mouth and nose and comparing the two ( organoleptic assessment ).

Organoleptic scoring scale

  • Absence of odor.
  • Questionable to slight malodor. Odor is deemed to exceed the threshold of malodor detection.
  • Moderate malodor. Odor is definitely detected.
  • Strong malodor. Malodor is objectionable but examiner can tolerate.
  • Severe malodor. Overwhelming malodor. Examiner cannot tolerate.

Various scoring systems, such as 0 to 5 point scale and a 0 to 10 point scale can be used to estimate the intensity of exhaled oral odor, tongue odor and nasal odor , among others.

Methods for objective measurement of the breath include :

  • Detection of sulphides with an appropriate monitor- simple but may fail to detect oral malodor caused by nonsulphide components. Halimeter is a instrument that can be used chair side to measure volatile sulfur compounds in the exhaled air.
  • Gas chromatography- not applicable for routine clinical practice.
  • Bacterial detection ( such as benzoylarginine – naphthylamide test – BANA test ) , polymerase chain reaction, dark field microscopy ) – not applicable for routine clinical practice.


  • Dental notes.
  • A practical manual of Public Health Dentistry – C M Marya.

Management of Odontogenic Infection

Written by : Dr.Urusa I Inamdar


  • Specimen collection and processing
  • Imaging techniques


  • prevention of the odontogenic infection is the golden standard.
  • complex odontogenic infection may require an incision and drainage.
  • mild odontogenic infection can be easily treated with simple antibiotic.
  • Complicated odontogenic infection require patient admission and hospitalization.
  • any odontogenic infection should be treated promptly and should not be underestimated.
  • Determine the severity of infection.
  • evaluate the host defence.

Severity of infection

  • Rate of progression.
  • Potential of airway compromise or affecting vital organs.
  • Anatomic location of infection.

Incision and drainage

  • Incise in healthy skin.
  • Incise in gravity dependent aesthetic area – if possible.
  • Explore entire abscess cavity.
  • Non – absorbable drains.

Principles in the use of drains

  • Drained wounds should be cleansed frequently.
  • Bacteria can migrate into a wound along the drain surface.
  • Latex Penrose drains are best used unmodified.

Empiric therapy of odontogenic infections

  • penicillin
  • penicillin + metronidazole
  • allergic to penicillin give clindamycin


  • Determine severity- assess history of onset and progression perform physical examination of area:
  1. Determine character and size of the swelling
  2. Establish presence of trismus
  • Evaluate host defense- evaluate:
  1. Diseases that compromise the host
  2. Medications that compromise the host
  • Perform surgery- remove the cause of infection , drain pus , relieve pressure.
  • Select antibiotic- Determine
  1. Most likely causative organisms based on history
  2. Host defense status
  3. Allergy history
  4. Previous drug history
  • Follow up- confirm treatment response, evaluate for side effects and secondary infections.

Follow up

  • out patient should return for f/u in 2-3 days.
  • Patient should have decreased swelling, discharge, airway edema, malaise in 2-3 days.
  • If no improvement consider:
  1. Re- culture
  2. Re- image
  3. Repeat incision and drainage


  • slideshare – odontogenic infection
  • Shafer’s – Textbook of Oral Pathology (7th edition)

Odontogenic Infections

Written by - Dr.Urusa I Inamdar

An odontogenic infection is an infection of the alveolus,jaws, or face that originates from a tooth or from its supporting structures and is one of the most frequently encountered infections.


  • dental caries
  • deep fillings
  • failed root canal treatment
  • periodontal disease
  • pericoronitis

Localised and spreading of odontogenic infection

infections have the potential to spread to other areas of the maxillofacial region and beyond through tissue planes and bloodstream.

A spreading odontogenic infection presents with varying degrees of facial swelling , trismus and pain , and can be life threatening.

Signs and symptoms

  • pain in the oral cavity and jaws
  • Swelling
  • mobile tooth
  • tenderness on biting or tapping on the affected tooth
  • Pain on Palpation of the surrounding gum
  • spontaneous drainage of pus

Red Flag suggestive of

  • Difficulty in speaking , swallowing and breathing
  • Dehydration
  • Trismus
  • Pyrexia
  • Raised tongue and floor of the mouth , drooling
  • Tachycardia and tachypnoae
  • Hypotension
  • Increased white blood cell count
  • Lymphadenopathy
  • Periorbital cellulitis

Clinical presentation

  • Dentoalveolar infection– swelling of the alveolar ridge with periodontal, periapical and subperiosteal abscess.
  • Submental space infection– firm midline swelling beneath the chin, caused by infection from the mandibular incisor.
  • Submandibular space infection– swelling of the Submandibular triangle of the neck around the angle of the mandible, caused by mandibular molars infection.
  • Sublingual space infection– swelling of the floor of the mouth with possible elevation of the tongue and dysphagia.
  • Retro pharyngeal space infection– stiff neck, sore throat, dysphagia and raspy voice, caused by the infections of the molars. It has high potential to spread to the mediastinum.
  • Buccal space infection– swelling of the cheek caused by infection of premolars and molars.
  • Masticator space infection– swelling on either side of the mandibular ramus, caused by infection of the mandibular third molars. Trismus is present.
  • Canine space infection– swelling of the anterior cheek with loss of the nasolabial fold and possible extension to the infraorbital region.

Complications of odontogenic Infections

  • respirtory obstruction
  • Sepsis
  • Endocarditis
  • Pericarditis
  • Necrotising fascitis
  • descending mediastinitis
  • spondylitis
  • brain abscess
  • cavernous sinus thrombosis
  • thoracic empyema
  • pleuropulmonary suppuration
  • aspiration pneumonia
  • pneumothorax
  • mandibular or Cervical osteomyelitis
  • abscess of the carotid sheath and jugular thrombophlebitis
  • hematogenous dissemination to distant organs and coagulation abnormalities.


  • Ogle OE . Odontogenic Infections. Dent Clin North Am.
  • ( Understanding Odontogenic Infections and its complications )
  • Shafer’s Textbook of Oral Pathology ( 7th edition )

Extraoral Examination of Temporomandibular Joint

Written by : Dr.Urusa I Inamdar

The importance is to determine deviation of jaw from the midline during the opening and closing of the jaws.

Causes of jaw deviation:

  • Traumatic injuries of the joint
  • Infection of the jaw
  • Fractures of the jaw
  • Muscular hypertrophy and hypotrophy

The lateral mandibular range of motion or movement is assessed ” Normal 8 to 10 mm ” by having the patient to occlude the teeth and then slide the jaw in both directions. The range of movement from midline and any pain, location and severity is recorded.

Maximum interincisal opening: As a general guide, mobility is considered to be reduced if the subject is unable to open his or her jaw to the width of two fingers ( <30 mm ).


  • Bimanual and bidigital Palpation or extra-auricular or intra-auricular.
  • Palpation may reveal pain and irregularities during condylar movement , described as clicking or crepitus. Clicking reveals the internal derangement of TMJ.
  • The lateral pole of condyle is most accessible for palpation during mandibular movements.
  • Palpation just anterior and posterior to the lateral pole detects pain associated with TMJ capsular ligament.
  • The comparison between both condyles must be assessed by palpation.

TMJ muscles :

Gravity muscles ( Depression of mandible )

  • Geniohyoid
  • Digastric
  • Mylohyoid

Anti-gravity muscles ( Elevation of mandible )

  • Medial , oblique , anterior , vertical of temporalis.
  • Medial Pterygoid , masseter .

Protrusion of mandible

  • Medial pterygoid.
  • Lateral pterygoid.

TMJ disorders :


  • Hypoplasia/aplasia of condyle
  • Hyperplasia of condyle
  • Bifid condyle


  • Dislocation of condyle
  • Fracture of condyle
  • Injury to articular disc


  • Osteoarthritis
  • Rheumatoid arthritis
  • Septic arthritis



  • A practical manual of Public Health Dentistry – C M Marya
  • Slide share – Diagnosis of Temporomandibular disorder- Kelly
  • TMJ Anatomy – Geeky medics