Acinic cell carcinoma

Acinic cell carcinoma is also known as serous cell carcinoma or adenocarcinoma. It is a malignant epithelial neoplasm in which neoplastic cells express acinar cell differentiation.


Acinic cell carcinoma tends to be encapsulated and lobulated and mostly affects parotid salivary gland. Inside the oral cavity it mostly affects lips and buccal mucosa. It affects middle age people more with a predilection towards females.


Microscopically it contains cells that are positive to periodic acid Schiff (PAS) staining.


Treatment generally includes the surgical excision of tumor saving the facial nerve unless it is involved. Lymph nodes may also be dissected in case of clinical involvement.Prognosis may be poor in case of association with pain or fixation or gross invasion.

ABFRACTION

What is abfraction?

• A new classification for noncarious dental lesions has evolved from the dental literature.
  
• The name given to these lesions is dental abfractions
  
• Abfraction is the microstructural loss of tooth substance in areas of stress concentration.
  
• These are "wear" points at the neck of the tooth, where the enamel has disappeared and dentin is exposed.

How does it occur?

• Enamel at the neck of the tooth is very thin or nonexistent to start with.  
• Teeth tend to experience all sorts of forces (vertical, horizontal, sheer, compressive) including bending forces which are focused at the neck of the tooth where the enamel is thin
• These forces over time cause some loss of enamel adjacent to the neck of the tooth and this allow exposed dentin to erode.
  
• The erosion associated with the abfraction continues as long as the dentin is exposed and tends to further undermine the tooth's enamel covering, which leads to further enamel loss.
  
• These lesions are typically wedge shaped with sharp line angles, but occlusal abfractions have been observed as circular invaginations 

Apart from above there could be other reasons like,

MISALIGNED TEETH

• Misaligned tooth/teeth.
• Clenching or grinding of teeth
  
• Erosion of teeth (e.g. acid like material on teeth).
  
• Abrasion of teeth (toothbrush abrasion e.g.).

What are the signs & symptoms of abfraction?

• Abfraction lesions don't hurt. They affect only the enamel, the outer layer of the tooth.
  
• Sometimes it exposes the tooth nerve and causes sensitivity to hot and cold.
  
• Abfraction lesions are fairly common in adults. Older adults are especially likely to have them.
  
• They occur more often in the back teeth, called premolars and molars. But they can occur in any tooth.
  
• Teeth with abfraction lesions are not more likely to decay, but they can get weaker over time. Weak teeth may be more likely to break.

How to diagnose?

• You can see them if you look in a mirror and shine a flashlight or bright light on your teeth. The lines usually run up and down the length of a tooth.
• Your dentist can see abfraction lesions during a regular dental examination. 

How can it be prevented?

Abfraction due to following reasons can be prevented,

Causes	Prevention
Misaligned teeth	Alignment of teeth or orthodontic treatment
Clenching or grinding of teeth while sleeping	Wearing night guards
Toothbrush abrasion	Learning correct toothbrushing techniques
Occlusal forces	occlusal equilibration and occlusal splints

Treatment

• Desensitizing toothpastes like Denquel or Sensodyne help reduce the sensitivity
  
• Treatment consists of the application of composite resin or glass-ionomer cement restorations and/or the discontinuance of the etiology of these lesions.

 

BEFORE TREATMENT

AFTER TREATMENT

If esthetics is not a primary concern of the patient and the tooth is not structurally compromised, many of these lesions can be observed over time.
 
References

• http://www.doctorspiller.com/Tooth_wear/attrition2.htm
• http://www.dawnmorehead.com/library.html
• http://www.oakvillefamilydentistry.com/dr-rosenblats-blog/2009/9/4/notches-or-grooves-in-my-teeth.html
  
• http://lspindelnycdds.blogspot.com/2006/10/what-are-abfractions.html
  
• http://www.atlantadentist.com/abfraction.html
  
• http://jada.ada.org/cgi/content/full/135/8/1109
  
• http://www.simplestepsdental.com/SS/ihtSS/r.==/st.32219/t.31403/pr.3.html
  
• http://www.ncbi.nlm.nih.gov/pubmed/8620386