Category Archives: How-To

Orthognathic Surgery : How to

Edited by : Dr. Hani Alhebshi

Orthognathic surgery is a type of surgery that is done to the jaws to correct a frank skeletal discrepancy.

The common steps in order are :

  • Pre-surgical orthodontic treatment (decompensation orthodontics).  This involves aligning the teeth on the jaws according to their basal bone , and may require extractions,  A few weeks before surgery when decompensation orthodontics is completed patient will undergo a surgical assessment and pre-planning.  This involves taking impressions, x-rays, pictures and models of the teeth as well as a face bow (jaw registration).  This will allow the surgeon to plan the movements of the jaw and the technician will be able to construct the splints required during surgery.
  • The surgery is usually performed under general anaesthetic and can take up to 3 or 5 hours to complete depending on how much jaw surgery is required.   The new position of the jaws is maintained with the use of plates and screws and on occasions these may be resorbable .  Most common surgical cuts involve : Maxillary LeFort I for maxillary impaction or advancement , Bilateral sagittal split osteotomy for mandibualr advancement or set back , and  genioplasty to either advance or set back the chin.
  • Post-surgical Orthodontic Treatment (following surgery) : Elastics are applied to the teeth to guide the new bite and the patient is put on a soft diet for 6 weeks.  During this time medications such as antibiotics, analgesics and nasal drops are often required in the first week or two after surgery.  Then elastics are removed after about six weeks and the final adjustments to teeth and bite are undertaken by the orthodontist in consultation with the surgeon.  The process can last a further three to six months depending on the complexity of the procedure.

Here are videos that shows the procedures done in different types of orthognathic surgery.

Lefort 1 Osteotomy HD

Bilateral Sagittal Split osteotomy

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How Systematic reviews are conducted?

By : Dr. Hani Alhebshi.

A systematic review is simply a structured and organized way to review many articles on specific topic and collecting their results and analyzing them with or without statistical methods; to reach a better conclusion on that topic under investigation.
If statistical methods were used ; It is called “Meta-analysis“.

For example :
If we want to make a systematic review on whether there is a relation between third molar impaction and late lower arch crowding , we raise the question : Is there a relation between them ?
Then we determine inclusion and exclusion criteria of papers that we are going to collect. They must be relevant to our topic. If articles found during our search has not matched our inclusion criteria ; they are ignored to others that match.
Then we organize data in tabular forms and analyze their results.
Analysis can summerize the net conclusion of whether they support or refute presence of any relation between molar impaction and lower arch crowding. Continue reading How Systematic reviews are conducted?

Sequence of archwires of 2 bracket prescriptions (0.018 and 0.022 slots)

This is a general guideline of the sequence of archwires during treatment which can be modified according to the clinical situation.

( Summerized from a lecture of Dr. Zuhair Bakhsh ).

*For 0.018 x 0.025 slot brackets

Phase I (Alignment&Leveling):

1.0.014 Niti

2.0.016 Nitti
Continue reading Sequence of archwires of 2 bracket prescriptions (0.018 and 0.022 slots)

How to Critique an article ..

Your final personal opinion about any scientific paper can be based on the collective answers of the following questions :
1. Title : is it appropriate and clear ?
2. Abstract : is it representative of the article and in correct form?
3. Purpose of the article : is it clearly stated ?
4. Errors of established facts or errors of interpretation of other’s work.
5. Is all the discussion relevant?
6. Are references the auther cited relevant to the topic?
7. Have any ideas been overemphasized or under emphasized?

Continue reading How to Critique an article ..