"Previously, a decrease in mandibular corpus height was reported to correlate with age23,31,32 and with status of dentition.10,13,15,17,22,40,42,43 It is well known that atrophy of the alveolar ridge is responsible for this reduction.3,16 This was corroborated in our study"

Thank you for the evidence that alveolar ridge atrophy is responsible for mandibular reduction. Could you please give me the reference for this citation?

Re: Charles Tweed. All of his case study research articles discuss and show recession. As he is the inventor of the extraction-retraction method, and his method developed in 1940 is the same one used today, you might wish to bring up your objection to the AAO, which endorses it. AAO endorsement of the Tweed method (how it is referred to) is the reason orthodontists continue to extract today.