Any of the Following findings could be the first sign that should trigger the diagnosis of aggressive periodontitis in the clinicians mind.
1. History of Progressive diastema formation between centrals which on examination looks distolabially rotated.
2. Mobile/severely recessed or missing mandibular anteriors inspite of good oral hygiene.
3. Patient gives history of recurrent swelling randomly in either of his/her first molar region (radiographically those molars will surely show some root resorption as well)
First sign i guess could be attachment loss in atleast 1 permanent molar which is not justifiable by the amount of deposits present.
First symptom (which eventually would depend of patients perception and awareness) could range from some food lodgement in embrassure of molar to mobility of lower anterior.
It would be a shame to wait until gross, macro signs of attack appear such as those noted above. We MUST have better measures of periodontal attack well BEFORE we observe mobility, attachment loss, purulence, bleeding, etc. At bare minimum would consider using phase microscopy, DNA salivary probes and BANA testing.
Often, the first sign would be the presence of clinical attachment loss not justifiable by the level of oral hygiene.
This might involve the first molar and incisors in localized aggressive periodontitis. What to do next is to request for a simple bitewing or periapical of the first molar and central incisors. The presence of vertical/angular bone loss "confirms" the diagnosis.
I say "confirmed" because with experience, microbiology is not compulsory for diagnosis. so much for the localized variety.
In generalized aggressive periodontitis, the patient presents with severe, CAL affecting several teeth not limited to the incisors and first molars. However, the level of CAL is still considering the oral hygiene. There might also be an underlying systemic condition.
Finally, I have come across the so-called atypical aggressive periodontitis in my practice which does not fit any textbook stereotypes. Such cases present with severe CAL in teeth not normally expected to be most affected.
You can take a look at this KAP paper here: http://tinyurl.com/qb3m3t8
I have also written a case series on this. I can send this to you privately if you send me your email address.
I take your point Dr. Ramachandra.. However, i feel the patient would come to see a dentist only when he /she sees movement in teeth or mobility .. He/she would not identify periodontal pockets. Thanks