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Is Alt-RAMEC protocol effective in the treatment of patients with a Class III malocclusion?


The claimed benefits of rapid maxillary expansion (RME) when combined with protraction facemask (PFM) include disarticulation of the circum-maxillary sutures and forward movement of the maxilla as a result of the palatal shelves pivoting around the pterygomaxillary junction (Haas 1970; Ngan et al. 1997; Turley 2007; Almuzian et al. 2018).

However, several studies have disclosed uncertainty with regard to the clinical benefits of RME in relation to maxillary protraction (Foersch et al. 2015).


Alternating Rapid Maxillary Expansion and Constriction (Alt-RAMEC) protocol was introduced more than a decade ago by Erik Liou in an effort to achieve greater forward movement of the maxilla following maxillary protraction (Liou and Tsai 2005).

Alt-RAMEC protocol

The original Alt-RAMEC protocol involved expansion of the maxilla (1mm/day) in the first week followed by constriction (1 mm/day) in the following week. This procedure was repeated for 7–9 weeks, so as to achieve maximum disarticulation of the maxillary sutures without consequent over-expansion (Liou and Tsai 2005).

Maxillary protraction: before, during or after Alt-RAMEC?

If the protraction is delayed until after Alt-RAMEC phase, treatment duration might be extended (Almuzian et al. 2018 & 2019)

Other suggested no waiting and the Alt-RAMEC can be started simultaneously with maxillary protraction to reduce treatment duration (Canturk & Celikoglu 2015).

Effectiveness of the combined Alt-RAMEC protocol and PFM

A systematic review that I undertook (Almuzian et al. 2018) showed that there is limited evidence with high risk of bias that Alt-RAMEC/PFM can result in a statistically significant increase in maxillary protraction compared with RME/PFM in Chinese subjects over the short-term. High-quality long-term RCTs with inclusion of patient-reported outcomes are required.


Based on my limited experience in this field, I have added my Alt-RAMEC protocol and more reading papers in the link below which can also be accessed from this code:


American Journal of Orthodontics and Dentofacial Orthopedics in its January 2021 issue published a new study that was undertaken by a team from China led by Dr Liu. The paper titled “Relative effectiveness of facemask therapy with alternate maxillary expansion and constriction in the early treatment of Class III malocclusion”.

The study recruited 39 preadolescent patients and aimed to compare the effectiveness of three interventions in treating Class III malocclusion:

1. PFM with no expansion (PFM),

2. PFM with conventional RME (RME/FM), and

3. PFM with Alt-RAMEC (Alt-RAMEC/ PFM)which was started simultaneously with maxillary protraction.

In summary, maxilla was protracted more in Alt-RAMEC group than other groups, the difference was mild (A-VRP, 3.87 mm vs 3.04 mm [RME/FM], vs 2.04 mm [FM]; P <0.05). However, mandibular clockwise rotation was less in the Alt-RAMEC/FM group which is beneficial if the FMPA is above average.

What do you think?

Link to the paper:


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