Microsoft Word - Herrera Proof Dec 2.docx   Vol  2,  No  1  (2014)   ISSN  2167-­‐8677  (online)   DOI  10.5195/d3000/2014.25           http://dentistry3000.pitt.edu     New  articles  in  this  journal  are  licensed  under  a  Creative  Commons  Attribution  4.0  United  States  License.     This  journal  is  published  by  the  University  Library  System,  University  of  Pittsburgh  as  part  of  its  D-­‐Scribe  Digital  Publishing  Program  and  is  cosponored   by  the  University  of  Pittsburgh  Press.   Prevalence  of  dental  anomalies  in  a  Mexican  population   Jose  R.  Herrera-­‐Atoche1,  Silvia  M.  Diaz-­‐Morales1,  Gabriel  E.  Colomé-­‐Ruiz1,  Mauricio  Escoffié-­‐Ramírez1,  María  Fernanda  Orellana2.     1Universidad  Autónoma  de  Yucatán,  Faculty  of  Den:stry,  Orthodon:c  Department   2University  of  California  San  Francisco,  School  of  Den6stry,  Department  of  Orofacial  Sciences Abstract   Background:  Data  on  dental  anomaly  prevalence  is  instrumental  to  diagnosis  and  treatment   in   different   popula+ons.   A   retrospec+ve   study   was   done   to   determine   dental   anomaly   prevalence   and   associa.ons   in   a   group   of   orthodon.c   pa.ents   in   a  Mexican   popula.on.   Methods:   Number,   shape,   erup.on   and   structural   dental   anomalies   were   assessed   from   the  records  of  670  subjects.  Prevalence,  distribu8on,  and  associa8ons  between  the  differ-­‐ ent  anomalies  were  calculated.  Chi-­‐squared  and  Fisher’s  exact  tests  (p<0.05)  were  used  to   iden%fy   significant   differences   by   sex,   and   to   establish   associa%ons   among   the   studied   anomalies.   Results:   Twenty-­‐eight   percent   of   the   sample   exhibited   at   least   one   dental   anomaly.  Sta+s+cal  analysis  iden+fied  no  differences  by  gender.  The  most  common  anoma-­‐ ly   was   impacted   teeth   (13.58%),   followed   by   microdon=c   upper   lateral   incisors   (6.26%).   These   two   anomalies   also   had   the   highest   number   of   significant   associa6ons   with   other   anomalies.   Conclusions:   The   dental   anomalies   prevalence   documented   here   differ   from   those   reported   in   the   literature   for  other  popula0ons   in   the  world.  Dental   anomalies   are   normally  associated  with  each  other  and  occur   in  groups   linked   to  ethnic  origin.  The  pre-­‐ sent   results   indicate   the   presence   of   differing   suites   of   anomalies   between   the   studied   Mexican  popula*on  and  other  popula*ons  in  the  world.  This  varia%on  highlights  the  need   for   further   research   on   dental   anomalies   in   La2n   America   to   aid   in   their   diagnosis   and   treatment.       Cita%on:Herrera-­‐Atoche   JR,   Diaz-­‐Morales   SM,   Colomé-­‐Ruiz   GE,   Escoffié-­‐Ramírez   M,   and   Orel-­‐ lana  MF.  (2014)  The  prevalence  of  dental  anom-­‐ alies   in   a   Mexican   popula.on.   Den.stry   3000.   1:a001  doi:10.5195/d3000.2014.25   Received:  June  16,  2014   Accepted:  November  24,  2014   Published:  December  10,  2014   Copyright:   ©2014   Herrera-­‐Atoche   et   al.   This   is   an  open  access  ar!cle  licensed  under  a  Crea!ve   Commons   A"ribu%on   Work   4.0   United   States   License.   Email:  jose.herrera@uady.mx       Introduc)on   Dental  anomalies  (DA)  can  represent  a  chal-­‐ lenge   for   attaining   ideal   occlusion   and   es-­‐ thetics   in   dentition.   Absence,   atypical   loca-­‐ tion   and   abnormal   tooth   shape   often   re-­‐ quire   interdisciplinary   treatment   involving   orthodontics,   surgery   and/or   oral   rehabili-­‐ tation.   Prevalence   of   DA   worldwide   varies   [1-­‐5],   probably   due   primarily   to   genetic   variation   between   ethnicities.   There   is   evi-­‐ dence  about  the  association  between  differ-­‐ ent   types   of   DA   within   populations   of   the   same  ethnicity  [6-­‐10].  For  example,  subjects   with   unilateral   peg-­‐shaped   maxillary   per-­‐ manent   lateral   incisors   can   have   up   to   a   55%  probability  of  exhibiting  lateral  incisor   agenesis  on  the  contralateral  side  [11].  Oth-­‐ er   examples   include   a   study   of   Japanese   subjects   with   agenesis   of   one   or   two   per-­‐ manent   mandibular   lateral   incisors,   which   had  signi)icantly  increased  prevalence  rates   of   other   permanent   tooth   agenesis   and   symmetrical   dental   agenesis   [12],   and   a   relation   between   third   molar   agenesis   and   impacted   canines   in   a   Portuguese   popula-­‐ tion  [13].   Several  studies  have  addressed  DA  in  differ-­‐ ent  populations.  In  Latin  America,  there  are   a  number  of   studies   of   isolated  DA,   but   re-­‐ ports   documenting   various   DA   in   a   Latino   population   are   rare.   One   example   is   a   re-­‐ ported  2.5%  DA  prevalence  in  primary  den-­‐ tition   (2-­‐5   year-­‐old   children)   in   a  Brazilian   population,   which   the   authors   stated       is   higher  than  in  other  populations  [14].  Given   the  sample  age  range  and  the  small  number   of  studied  DA,   it   is  probable  that  DA  preva-­‐ lence   in   an   older   population   would   vary   more  broadly.   Malocclusion   and   aesthetic   problems   are   only   some   of   the   problems   caused   by   DA.   Data   on   DA   prevalence   and   associations   is   vital   to   diagnosis   of   dental   disorders   and   treatment   planning.   The   objective   of   the   present   study   was   to   document   DA   preva-­‐ lence   and   association   in   orthodontic   pa-­‐ tients  in  a  Mexican  population.     Materials  and  Methods   A  retrospective  study  was  done  of  a  sample   of   690   records   for   orthodontic   patients   ex-­‐ amined   by   three   calibrated   orthodontists.   Records   were   from   the   orthodontic   clinic   archives   at   the   Autonomous   University   of   Yucatan  (Universidad  Autónoma  de  Yucatan   –   UADY),   Merida,   Yucatan,   Mexico.   Patient   age   ranged   from   9   to   20   years   of   age.   All   patients   were   of   Mexican   origin.   Subjects   with  a  history  of   trauma,  prior  orthodontic   treatment,  cleft   lip  and  palate  or  other  syn-­‐ dromes  were  excluded.  Incomplete  or  inad-­‐ equate   records   lacking   quality   data   (e.g.   photographs,  dental  casts,  x-­‐rays,  etc.)  were   eliminated.   Following   these   criteria,   20   pa-­‐ tients  were   eliminated   from   the   sample.  Of   the   remaining   670   subjects,   65.38%   were   female  (n=438)  and  34.62%  male  (n=232)   A  total  of  12  DA  were  assessed:      Prevalence  of  dental  anomalies  in  a  Mexican  popula5on   Vol  2,  No  1  (2014)        DOI  10.5195/d3000/2014.25    http://dentistry3000.pitt.edu   2   1.   Dental   agenesis.   Dental   agenesis  was   di-­‐ agnosed   when   “no   mineralization   of   tooth   crown   could   be   identi.ied   on   orthopan-­‐ tomograms  or  a  full-­‐mouth  set  of  periapical   radiographs,   and   no   evidence   of   its   having   been   extracted  was   found”   [15].   Third  mo-­‐ lars  were  excluded.   2.  Supernumerary  teeth  (SNT).  A  tooth  was   considered   as   supernumerary  when   "it   ap-­‐ pears   in   addition   to   the   regular   number   of   teeth"  [2].     3.   Microdontic   upper   lateral   incisors   (MU-­‐ LI).  Diagnosed  when  an  upper  lateral  incisor   presents   “mesio-­‐distal   width   equal   to   or   smaller  than  that  of  its  mandibular  counter-­‐ part”   [7].   The   measurements   were   made   with  a  Mitutoyo  digital  caliper  (Aurora,   Illi-­‐ nois,  USA).   4.   Peg-­‐shaped   upper   lateral   incisors   (PSULI).  An  upper  lateral  incisor  was  classi-­‐ !ied   as   peg-­‐shaped   when   “mesio-­‐distal   width  was   greatest   at   the   cervical  margin”   [7].   5.   Barrel-­‐shaped   upper   lateral   incisors   (BSULI).  An  upper  lateral  incisor  was  classi-­‐ !ied   as   barrel-­‐shaped   when   a   “pronounced   manifestation   of   a   thickened   or   elevated   cingulum  was   found   on   the   gingival   aspect   of  lingual  surfaces”  [16].   6.   Upper   lateral   incisors   with   talon   cusp   (TC).  TC  was  de,ined  as  an  “accessory  cusp-­‐ like   structure   that   projects   from   the   cingu-­‐ lum  area  or  cementoenamel  junction”  [17].   7.   Fusion.   This   was   diagnosed   “if   [tooth]   crown   and   root   were   enlarged   and   tooth   count  revealed  a  missing  tooth”  [18].   8.   Gemination.   A   tooth   was   considered   to   have  gemination   if   its  “crown  was  enlarged   with  a  normal  root  and  the  tooth  count  was   normal”  [18].   9.   Impacted   teeth   (IT).  A   tooth  was  consid-­‐ ered  impacted  when  “it  was  not  expected  to   erupt   completely   into   its  normal   functional   position  based  on   clinical   and   radiographic   assessments”   [2].   Third   molars   were   ex-­‐ cluded.   10.  Transposition.  This  was  de2ined  as   “the   positional   interchange   of   two   adjacent   teeth,   or   the   development   or   eruption   of   a   tooth   in   a   position   normally   occupied   by   a   non-­‐adjacent  tooth”  [8].   11.  Transmigration.  A  tooth  was  considered   to  be  in  a  transmigrated  position  when  “the   eruption   path   had   been   altered   and   the   tooth  had  drifted  to  the  opposite  side  of  the   arch  with   at   least   half   of   the   crown   length   crossing  the  midline”  [19].   12.   Amelogenesis   imperfecta   (AI).   This   structural   anomaly   “represents   a   group   of   developmental   conditions,   genomic   in   origin,  which   affect   the   structure   and   clini-­‐ cal  appearance  of  enamel  of  all  or  nearly  all   the   teeth   in   a   more   or   less   equal   manner,   and  which  may  be  associated  with  morpho-­‐ logic   or   biochemical   changes   elsewhere   in   the   body”   [20].   No   subgroups   were   distin-­‐ guished  for  the  present  study.   Statistical  analysis   Once  the  DA-­‐positive  population  was  identi-­‐ !ied,   DA   prevalence   and   distribution   were   calculated.   A   Chi-­‐squared   test   or   Fisher’s   exact   test  were   used   to   identify   any   differ-­‐ ences   between   sexes   and   any   associations   between  the  different  DA  (P  <0.05).     Results   Of  the  670  subjects,  28.05%  (n=188)  exhib-­‐ ited   at   least   one   dental   anomaly.   Distribu-­‐ tion   by   gender   was   62.76%   (n=118)   in   fe-­‐ males  and  37.23%  (n=70)  in  males,  with  no   differences  (p>0.05)  in  frequency.  The  most   prevalent   DA   was   IT   (13.58%;   n=91),   fol-­‐ lowed  by  MULI  (6.26%;  n=42)  (Table  1).     Number  of  anomalies   Dental   agenesis   was   present   in   5.82%   (n=39)  of  the  subjects.  A  total  of  66  cases  of   absent  teeth  were  identi-ied,  47  (71.21%)  of   which   were   a   lower   tooth.   The   most   com-­‐ monly   absent   tooth   was   the   second   lower   premolar   (25.75%,   n=17)   followed   by   the   lower   lateral   (22.72%,  n=15).   In   the  maxil-­‐ lary   arch,   the  most   frequently   absent   teeth   were  the  lateral  incisors  (10.60%,  n=7)  and   the  second  molars  (10.60%,  n=7).  A  total  of   40   (5.97%)   SNT   were   identi5ied,   33   of   which   were   in   the   upper   arch   (73.33%);   mesiodens   were   the   most   common   SNT   (n=19).   Shape  anomalies   The  most  frequent  shape  anomaly  was  MU-­‐ LI   (6.26%;   n=42).   Of   these   42   subjects,   18   had  bilateral   affectation,   raising   the  overall   MULI   total   to   60.   A   total   of   29   (48.33%)   cases   were   on   the   right   side   and   31   (51.66%)   on   the   left.   Ten   (1.49%)   PSULI   cases  were  identi,ied;  ,ive  patients  present-­‐ ed   bilaterally,   producing   an   overall   total   of   15   PSULI   teeth   (9   left/6   right).   Prevalence   for   BSULI   was   2.83%   (n=19);   two   cases   were   bilateral,   for   a   total   of   21   affected   teeth   (11   left,   10   right).   Upper   lateral   inci-­‐ sors  with  TC  were  found  in  7  (1.04%)  cases;   the  right  side  was  most  affected  (n=5),  and   no   bilateral   affectations   were   identi)ied.   Only   two   male   patients   exhibited   fusion   (0.3%).   In   one   case,   the   lower   right   lateral   and  central  incisor  were  affected  and  in  the   other   the   lower   central   incisors   were   in-­‐ volved.   No   gemination   cases   were   present   in  the  sample.   Eruption  anomalies   Prevalence   for   IT   was   13.58%   (n=91),   alt-­‐ hough   the   total   number   of   teeth   exhibiting   IT  was  123:  96   in   the  upper  arch  (78.05%)   and   27   in   the   lower   (21.95%).   The   most   affected   tooth   was   the   upper   canine   (48.78%;  n=60),  followed  by  the  upper  cen-­‐ tral   incisor  and   the  upper  second  premolar   (13.01%;  n=16  in  both  cases).  Transposition   was   noted   in   16   cases   (2.38%)   and   was   present  only  in  the  maxillary  arch.  Bilateral   transposition  was  present  in  three  patients,   raising   the   total   to   19   teeth.   Transposition   of   the   upper   canines   and   laterals   was   the   most  common  (10  cases,  .ive  per  side).  This   next   most   common   con*iguration   was   transposition   of   the   upper   canine  with   the   !irst   premolar   (8   cases,   four   per   side).   In   only   one   case,   the   upper   canine   had   trans-­‐ posed   with   the   second   premolar   on   the   right  side.   Just  one  (0.14%)  subject  (female)  exhibited   transmigration;   in   this   case,   of   the   lower   right  canine.   Structural  anomalies   Three  female  subjects  exhibited  AI  (0.44%).   No   differences   (p>0.05)   by   gender   were   identi&ied   for   any   of   the   studied   DA.   Nine   signi%icant   (p<0.05)   associations   were   found  between  different  DA:   IT  with  dental   agenesis,   SNT,   MULI,   BSULI   and   transposi-­‐ tion;  MULI  with  PSULI,  BSULI  and  transposi-­‐ tion;   and   transposition   with   BSULI   (Table   2).            Prevalence  of  dental  anomalies  in  a  Mexican  popula5on   Vol  2,  No  1  (2014)        DOI  10.5195/d3000/2014.25    http://dentistry3000.pitt.edu   3   Discussion   Overall   DA   prevalence   in   the   sample   was   28.05%  (n=188).  Prevalence  rates  reported   in   different   studies   range   from   5.46%   to   74.77%   [1-­‐5,21],   but   the   present   results   were   nearest   those   reported   for   a   popula-­‐ tion   in   Egypt   [21].   This   high   variation   in   prevalence  values  may  be  due  to  differences   in   sample   sizes,   nature   of   the   sample   (or-­‐ thodontic,   dental,   or   general   population),   and  the  number  and  type  of  anomalies  stud-­‐ ied.   However,   exclusion   of   eruption   and   position   anomalies   substantially   reduces   these  prevalence  rates.   In   the  present  sam-­‐ ple,   no   difference   (p>0.05)   in   prevalence   was   present   between   genders.   The   most   prevalent   DA   was   IT   (13.58%;   n=91),   fol-­‐ lowed  by  MULI  (6.26%;  n=42).   Number  of  anomalies   Dental   agenesis   prevalence   was   5.82%   (n=39),   within   the   2.7   to   13.3%   range   re-­‐ ported   worldwide   [1,3-­‐5,15,22-­‐25].   In   pre-­‐ vious  reports  on  Mexican  populations,  2.7%   [22]   and   4.5%   [23]   prevalence   was   ob-­‐ served.  The  difference  between  the  present   results   and   these   studies   may   be   at   least   partially   due   to   genetic   variation   between   populations   in   different   regions   of   Mexico   [26].  The  most   frequently  absent  tooth  was   the   lower   second   premolar,   which   concurs   with  other  reports  [1,15,25].   In  the  present   sample,  dental  agenesis  was  associated  with   IT   (p=0.023),   an   association   reported   else-­‐ where   [9,10,24],   and   possibly   linked   to   shared  genetic  origins.   Global   SNT   prevalence   varies   from   0.3   to   6%   [1,2,4,27-­‐30].   The   prevalence   observed   in   the  present  sample   (5.97%)   is   similar   to   that  reported  in  an  African-­‐American  popu-­‐ lation  [27].  Of  note  is  that  SNT  prevalence  in   the  African-­‐American   population  was   high-­‐ er  in  the  molar  and  premolar  regions,  while   in   the   present   study   it   was   higher   in   the   maxillary   anterior   region,   which   is   similar   to  other   reports   [1,2,4,28-­‐30].   It   can  be  ex-­‐ pected   that,   since   SNT   tends   to   block   the   eruption  path  of  other  teeth,   it  was  statisti-­‐ cally   associated  with   IT   (p=0.008).   For   this   same  reason,   this  association  appears  to  be   more   related   to   the   eruption   path   and   not   necessarily  of  genetic  origin.   Shape  anomalies   Comparison   of   microdontic   teeth   between   studies  can  be  challenging  since  each  report   tends   to   quantify   them   differently;   some   include   just   the   upper   laterals   [6],   others   the   upper   and   lower   laterals   [4],   others   include  all  teeth  [2],  etc.  In  previous  reports,   MULI   ranges   from   as   low   as   2.58%   to   the   6.26%  reported  in  the  present  study  [3,5,6].   Associations  were  found  between  MULI  and   four   other   DA   in   the   present   study   (Table   2).   The   associations   with   IT   (p=0.0007)   coincide   with   previous   reports   [6,31],   as   does   that   with   dental   transposition   (p=0.002)  [32].   Prevalence   for   PSULI   was   1.49%,   which   is   within  the  0.37  to  9.9%  range  of  previously   reported   values   [1,5,33].   If   differences   due   to  ethnicity  are  excluded,  this  high  variabil-­‐ ity   may   be   heavily   in-luenced   by   sample   size;   indeed,   the   larger   the   sample   size   the   lower   the   prevalence.   As   expected,   PSULI   was   associated   with   microdontia   (p=0.0001).   Worldwide,   BSULI   is   normally   associated   with   East   Asian   populations,   although   its   prevalence   in   this   study   was   higher   than   that  reported  for  a  sample  from  China  [16].   In   the   present   results,   prevalence   for   this   DA  was  higher  than  other  upper  lateral  inci-­‐ sor   shape   anomalies.   This   is   interesting   because  peg-­‐shaped  or  TC  teeth  are  studied   more  frequently  than  barrel-­‐shaped  anoma-­‐ lies,  which  are  not  commonly  reported.  The   statistical   associations   observed   here   be-­‐ tween   BSULI   and   other   DA,   such   as   IT   (p=0.008)   and   transposition   (p=0.0001),   imply  genetic   causes.  As  with  PSULI,  BSULI   was   associated   with   microdontia   (p=0.0001).  Further  research  in  Latin  Amer-­‐ ican   populations   would   aid   in   supporting   these  associations  and  identifying  their  dis-­‐ tribution  in  the  region.   Fused   teeth   were   present   in   only   0.3%   of   subjects,   a   prevalence   similar   to   those   re-­‐ ported   in   Indian   (0.27%)   [5]   and   Turkish   populations  (0.23%)  [4].   Eruption  anomalies   The  13.58%  (n=91)  prevalence  for  IT  in  the   present   study   made   it   the   most   prevalent   DA   in   the   study.   This   prevalence   is   similar   to  that  reported  for  a  Greek  population  [30],   and   at   the   high   end   of   the   0.49   to   13.7%   range   reported   in   the   literature   Dental Male Female Total p Male Female Anomalies n=232 (34.62%) n=438 (65.38%) n=670 (100%) Risk/Ratio Risk/Ratio Agenesis 14 (2.09) 25 (3.73) 39 (5.82) 0.863 1.06 0.95 SNT 18 (2.69) 22 (3.28) 40 (5.97) 0.157 1.54 0.65 MULI 16 (2.38) 26 (3.88) 42 (6.26) 0.625 1.16 0.86 PSULI 4 (0.6) 6 (0.89) 10 (1.49) 0.719 1.26 0.79 BSULI 6 (0.89) 13 (1.94) 19 (2.83) 0.777 0.87 1.15 Upper laterals with TC 5 (0.74) 2 (0.3) 7 (1.04) 0.062 4.72 0.21 Fusion 2 (0.3) 0 (0.00) 2 (0.3) - - - Gemination 0 (0.00) 0 (0.00) 0 (0.00) - - - IT 31 (4.63) 60 (8.95) 91 (13.58) 0.903 0.96 1.03 Transposition 7 (1.04) 9 (1.34) 16 (2.38) 0.439 1.49 0.68 Transmigration 0 (0.00) 1 (0.14) 1 (0.14) - - - AI 0 (0.00) 3 (0.44) 3 (0.44) - - - Table  1.  Prevalence and distribution of dental anomalies by sex in a group of 670 patients.   Abbreviations:Abbreviations:  (STN)  Supernumerary  Teeth;  (MULI)  Microdontic  upper  lateral  incisors;  (PSULI)  Peg-­‐shaped  upper  lateral  incisors;  (BSULI)  Barrel-­‐shaped   upper  la  uppe    lateral  incisors;  (TC)  Talon  cusp;  (IT)  Impacted  teeth;  (AI)  Amelogenesis  imperfecta        Prevalence  of  dental  anomalies  in  a  Mexican  popula5on   Vol  2,  No  1  (2014)        DOI  10.5195/d3000/2014.25    http://dentistry3000.pitt.edu   4   [1,2,5,19,30].  Variations  can  be  explained  as   a   consequence   of   sample   nature,   subject   ethnicity,  and  sample  size.  Despite  this  wide   value   range   among   studies,   all   the   reports   concur  in  that  the  upper  canine  is  the  most   frequently   impacted   tooth   [1,2,5,19,30].   As   mentioned  previously,  when  SNT  is  present   impaction   is   an   apparent   consequence,   whereas  its  association  with  other  DA  (MU-­‐ LI,   BSULI,   transposition,   and   dental   agene-­‐ sis)   is   more   probably   of   genetic   origin   [6,7,10,31].     The   prevalence   rate   of   transposition   was   relatively   high   (2.38%)   compared   to   other   reports:  0.27%  [34],  0.33%  [35],  and  0.81%   [32].   However,   the   present   data   coincides   with  these  previous  studies   in   that   the  uni-­‐ lateral   presentation   is   the   most   common,   and   that   the  maxillary   arch   is   the  most   af-­‐ fected   [34-­‐36].  As  reported  elsewhere   [34],   all  transposition  cases  in  the  present  sample   involved   the   canine   teeth.   Several   DA   are   reported  to  be  associated  with  transposition   [32,34,36].  The  DA  associated  with  transpo-­‐ sition   (MULI,   BSULI,   IT)   in   the   present   re-­‐ sults   suggest   a   genetic   origin   for   this   phe-­‐ nomenon.   Only   one   female   patient   exhibited   transmi-­‐ gration   in   the   mandible.   This   is   consistent   with  a  report  that  the  most  common  occur-­‐ rence   of   canine   transmigration   is   in   the   lower  arch  in  women  [19].   Structural  anomalies   The   0.44%   AI   prevalence   observed   in   the   present  data   is  very  near   the  0.43%  preva-­‐ lence  reported  for  a  Turkish  population  [4],   and   only   slightly   higher   than   the   0.27%   prevalence   found   in   an   Indian   population   [5].   The   DA   prevalence   documented   in   this   or-­‐ thodontic  population  from  Mexico  varied  in   many  respects  from  those  reported  for  oth-­‐ er  populations  in  the  world.  The  most  prev-­‐ alent  DA  were   IT  and  MULI,   and   these  also   had   the  highest  number  of   signi1icant  asso-­‐ ciations   with   other   DA.   Given   that   dental   anomalies   are   primarily   of   genetic   origin,   this  prevalence  vary  widely  between  ethnic-­‐ ities.   Little   DA   data   is   available   for   Latin   American   populations,   further   research   in   the   region   is   clearly  needed   to  advance   the   ability   of   dental   health   professionals   to   di-­‐ agnose  and  effectively  treat  these  disorders.     References   1.  Prevalence  of  dental   anomalies   in  orthodontic   patients.  Thongudomporn  U,  Freer  TJ.  Aust  Dent  J.   1998  Dec;43(6):395-­‐8.  PMID:  9973708.   2.  Prevalence  of  dental  anomalies  in  various  mal-­‐ occlusions.  Uslu  O,  Akcam  MO,  Evirgen  S,  Cebeci  I.   Am   J   Orthod   Dentofacial   Orthop.   2009   Mar;135(3):328-­‐35.  PMID:  19268831.     3.  Evaluation  of  the  Prevalence  of  Dental  Anoma-­‐ lies  in  Children  in  the  Canton  of  Sarajevo.  Spahić-­‐ Dizdarević   M,   Deljo   E,   Ganibegović-­‐Selimović   M.   Acta  Stomatol  Croat.  2011;45(1):24-­‐30.     4.   Prevalence   and   distribution   of   dental   anoma-­‐ lies  in  orthodontic  patients.  Altug-­‐Atac  AT,  Erdem   D.   Am   J   Orthod   Dentofacial   Orthop.   2007   Apr;131(4):510-­‐4.  PMID:  17418718.   5.   Prevalence   and   distribution   of   selected   devel-­‐ opmental   dental   anomalies   in   an   Indian   popula-­‐ tion.  Gupta  SK,  Saxena  P,   Jain  S,   Jain  D.  J  Oral  Sci.   2011;53(2):231-­‐8.  PMID:  21712629.     6.  A  controlled  study  of  associated  dental  anoma-­‐ lies.   Baccetti   T.   Angle   Orthod.   1998   Jun;68(3):267-­‐74.  PMID:  9622764.     7.   The   incidence   of   anomalous   maxillary   lateral   incisors  in  relation  to  palatally-­‐displaced  cuspids.   Becker   A,   Smith   P,   Behar   R.   Angle   Orthod.   1981   Jan;51(1):24-­‐9.  PMID:  6939351.       8.   Maxillary   canine-­‐!irst   premolar   transposition,   associated   dental   anomalies   and   genetic   basis.   Peck  L,  Peck  S,  Attia  Y.  Angle  Orthod.  1993  Sum-­‐ mer;63(2):99-­‐109.  PMID:  8498708.       9.  Agenesis  of  maxillary  lateral  incisors  and  asso-­‐ ciated   dental   anomalies.   Garib   DG,   Alencar   BM,   Lauris   JR,   Baccetti   T.   Am   J   Orthod   Dentofacial   Orthop.   2010   Jun;137(6):732.e1-­‐6.   PMID:   20685523.     10.   Maxillary   palatal   ca-­‐ nine   impaction   displace-­‐ ment   in   subjects   with   congenitally  missing  max-­‐ illary  lateral  incisors.  Al-­‐ Nimri   KS,   Bsoul   E.   Am   J   Orthod   Dentofacial   Or-­‐ thop.   2011   Jul;140(1):81-­‐6.   PMID:   21724091.     11.   Prevalence   of   peg-­‐ shaped   maxillary   per-­‐ manent   lateral   incisors:   A   meta-­‐analysis.   Hua   F,   He  H,  Ngan  P,  Bouzid  W.   Am  J  Orthod  Dentofacial   Orthop.   2013   Jul;144(1):97-­‐109.   PMID:  23810051.   12.   Association   of   agen-­‐ esis   of   mandibular   lat-­‐ eral   incisors   with   other   dental   anomalies   in   a   Japanese  population.  Endo  S,  Sanpei  S,  Takakuwa   A,  Takahashi  K,  Endo  T.  J  Dent  Child  (Chic).  2013   Jan-­‐Apr;80(1):9-­‐15.  PMID:  23595238.       13.  Dental  anomalies  in  a  Portuguese  population.   Campoy  MD,  González-­‐Allo  A,  Moreira  J,  Ustrell   J,   Pinho   T.   Int   Orthod.   2013   Jun;11(2):210-­‐20.   PMID:  23541047.   14.  Dental  anomalies  and  associated  factors  in  2-­‐   to  5-­‐year-­‐old  Brazilian  children.  Kramer  PF,  Feld-­‐ ens  CA,  Ferreira  SH,  Spiguel  MH,  Feldens  EG.  Int  J   Paediatr   Dent.   2008   Nov;18(6):434-­‐40.   PMID:   18435724.   15.  A  survey  of  hypodontia  in  Japanese  orthodon-­‐ tic  patients.   Endo  T,  Ozoe  R,  Kubota  M,  Akiyama   M,   Shimooka   S.  Am   J  Orthod  Dentofacial  Orthop.   2006  Jan;129(1):29-­‐35.  PMID:  16443475.   16.  Incisal  morphology  of  southern  Chinese.  Ling   JYK,  Wong  RWK.  Open  Anthropol  J.  2008;1:19-­‐25.     17.   Talon   cusp-­‐clinical   signi)icance   and  manage-­‐ ment:   case   reports.   Hattab   FN,   Yassin   OM,   al-­‐ Nimri  KS.  Quintessence   Int.  1995  Feb;26(2):115-­‐ 20.  PMID:  7568721.   18.   Prevalence   of   fused   and   geminated   teeth   in   Jordanian   adults.   Hamasha   AA,   Al-­‐Khateeb   T.   Quintessence   Int.   2004   Jul-­‐Aug;35(7):556-­‐9.   PMID:  15259971.   19.   The   incidence   of   canine   transmigration   and   tooth   impaction   in   a   Turkish   subpopulation.   Ak-­‐ tan  AM,  Kara  S,  Akgunlu  F,  Malkoc  S.  Eur  J  Orthod.   2010  Oct;32(5):575-­‐81.  PMID:  20237077.   20.  Amelogenesis  imperfecta.  Crawford  PJ,  Aldred   M,  Bloch-­‐Zupan  A.  Orphanet  J  Rare  Dis.  2007  Apr   4;2:17.  PMID:  17408482.   21.  Prevalence  and  distribution  of  dental  anoma-­‐ lies   in  orthodontic  patients.  Montasser  MA,  Taha   M.   Orthodontics   (Chic).   2012;13(1):52-­‐9.   PMID:   22567616.   22.   Radiographic   assessment   of   congenitally   missing   teeth   in  orthodontic  patients.  Silva  Meza   AGENESIS SNT MULI PSULI BSULI TALON CUSP IT SNT 0.8191 MULI 0.082 0.3154 PSULI 0.5696 0.5879 0.0001* BSULI 0.0597 NA 0.0001* NA TALON CUSP 0.3363 NA 0.379 NA NA IT 0.0235* 0.0081* 0.0007* 0.5506 0.0086* 0.9564 TRANSPOSITION 0.9409 0.9619 0.002* NA 0.0001* NA 0.0003* ! Table  2.  Associa.ons  between  dental  anomalies  calculated  by  Chi-­‐squared  and  Fisher  exact  tests.   Abbrevia(ons:   (STN)   Supernumerary   Teeth;   (MULI)   Microdon(c   upper   lateral   incisors;   (PSULI)   Peg-­‐shaped   upper   lateral   incisors;   (BSULI)  Barrel-­‐shaped  upper  lateral  incisors;  (IT)  Impacted  teeth;  (AI)  Amelogenesis  imperfecta  (*)  Sta(s(cally  significant  (p<0.05).          Prevalence  of  dental  anomalies  in  a  Mexican  popula5on   Vol  2,  No  1  (2014)        DOI  10.5195/d3000/2014.25    http://dentistry3000.pitt.edu   5   R.   Int   J   Paediatr   Dent.   2003   Mar;13(2):112-­‐6.   PMID:  12605629.   23.   Agenesis   in   permanent   dentition.   Díaz-­‐Pérez   R,   Echaverry-­‐Navarrete   RA.   Rev   Salud   Pública   (Bogota).   2009   Dec;11(6):961-­‐9.   PMID:   20379669.   24.   Prevalence   of   hypodontia   in   orthodontic   pa-­‐ tients  in  Brasilia,  Brazil.  Gomes  RR,  da  Fonseca  JA,   Paula  LM,  Faber  J,  Acevedo  AC.  Eur  J  Orthod.  2010   Jun;32(3):302-­‐6.  PMID:  19837747.   25.   Survey   on   hypodontia   in   Sayada,   Tunisia.   Maatouk   F,   Baaziz   A,   Ghnima   S,   Masmoudi   F,   Ghedira   H.   Quintessence   Int.   2008   Mar;39(3):e115-­‐20.  PMID:  18618026.   26.   Analysis   of   genomic   diversity   in   Mexican   Mestizo   populations   to   develop   genomic   medi-­‐ cine  in  Mexico.  Silva-­‐Zolezzi  I,  Hidalgo-­‐Miranda  A,   Estrada-­‐Gil  J,  Fernandez-­‐Lopez  JC,  Uribe-­‐Figueroa   L,  Contreras  A,  Balam-­‐Ortiz  E,  del  Bosque-­‐Plata  L,   Velazquez-­‐Fernandez  D,  Lara  C,  Goya  R,  Hernan-­‐ dez-­‐Lemus   E,   Davila   C,   Barrientos   E,   March   S,   Jimenez-­‐Sanchez  G.  Proc  Natl  Acad  Sci  USA.  2009   May  26;106(21):8611-­‐6.  PMID:  19433783.   27.   An   epidemiological   study   of   hyperdontia   in   American  blacks  and  whites.  Harris  EF,  Clark  LL.   Angle   Orthod   2008   May;78(3):460-­‐5.   PMID:   18416616.   28.   Supernumerary   teeth   vary   depending   on   gender.  Küchler  EC,  Costa  AG,  Costa  Mde  C,  Vieira   AR,   Granjeiro   JM.   Braz   Oral   Res.   2011   Jan-­‐ Feb;25(1):76-­‐9.  PMID:  21359454   29.  Supernumerary  teeth  in  a  Turkish  population.   Esenlik   E,   Sayin   MO,   Atilla   AO,   Ozen   T,   Altun   C,   Basak   F.   Am   J   Orthod   Dentofacial   Orthop.   2009   Dec;136(6):848-­‐52.  PMID:  19962608.   30.   Incidence   of   impacted   and   supernumerary   teeth-­‐a   radiographic   study   in   a   North   Greek   population.  Fardi  A,  Kondylidou-­‐Sidira  A,  Bachour   Z,   Parisis   N,   Tsirlis   A.   Med   Oral   Patol   Oral   Cir   Bucal.  2011  Jan  1;16(1):e56-­‐61.  PMID:  20711166.   31.   The   palatally   displaced   canine   as   a   dental   anomaly  of   genetic   origin.   Peck   S,   Peck  L,  Kataja   M.   Angle   Orthod.   1994;64(4):249-­‐56.   PMID:   7978519.       32.  A  retrospective  study  on  69  cases  of  maxillary   tooth  transposition.  Cho  SY,  Chu  V,  Ki  Y.  J  Oral  Sci.   2012;54(2):197-­‐203.  PMID:  22790413.   33.   Variations   in   number   and   morphology   of   permanent   teeth   in  7-­‐year-­‐old   Swedish   children.   Bäckman  B,  Wahlin  YB.  Int   J  Paediatr  Dent.  2001   Jan;11(1):11-­‐17.  PMID:  11309867.       34.   Investigation  of   tooth  transposition   in  a  non-­‐ syndromic  Turkish  anatolian  population:   charac-­‐ teristic  features  and  associated  dental  anomalies.   Celikoglu  M,  Miloglu   O,   Oztek   O.  Med   Oral   Patol   Oral  Cir  Bucal.  2010  Sep  1;15(5):e716-­‐20.  PMID:   20173710.   35.   Prevalence   of   tooth   transposition.   A   meta-­‐ analysis.   Papadopoulos   MA,   Chatzoudi   M,   Kaklamanos   EG.   Angle   Orthod.   2010   Mar;80(2):275-­‐85.  PMID:  19905852.   36.  Dental   transposition  as   a   disorder   of   genetic   origin.   Ely   NJ,   Sherriff   M,   Cobourne   MT.   Eur   J   Orthod  2006  Apr;28(2):145-­‐51.  PMID:  16373452.