Classification of maxillary central incisors-implications for immediate implant in the esthetic zone.
OBJECTIVE
This is the first study to analyze the positions and angulations of the central maxillary incisors with reference to the alveolus, providing data for clinicians to achieve good esthetic results for immediate implant placement in the esthetic zone.


METHODS
A total of 300 cone beam images were selected randomly. Five aspects were measured: the thickness of the palatal and buccal bone at their mid-root and apical level and the apical bone height. A classification was established according to the positions and angulations of the tooth.


RESULTS
The data from 170 cone beam images were included in the present study. The mean thickness of the buccal bone at the mid-root level was 0.9 ± 0.4 mm and at the apical level was 2.04 ± 1.01 mm. The mean thickness of the palatal bone at the mid-root level was 3.76 ± 1.37 mm and at the apical level was 8.51 ± 2.54 mm. The mean apical bone height was 9.53 ± 2.76 mm. The proportion of incisors positioned more buccally (type B) was 78.8%, 19.4%, and 1.8% positioned midway (type M) and more palatally (type P), respectively. Regarding the angulation, 49.9% were classified as type 2 (toward buccal), 34.7% as type 3 (toward buccal, with the long axis anterior to the A point), and 15.4% were categorized as type 1 (toward palatal or parallel to the alveolus).


CONCLUSIONS
We recommend that clinicians appreciate the socket in 3 dimensions to achieve a good outcome. According to the difficulty of achieving good results, the cases were categorized as levels I to III and recommendations were given.
Branemark Osseointegration Centre, Hong Kong, People's Republic of China. alfred.lau@disc-hk.com
Sze Lok
SL
Lau
James
J
Chow
William
W
Li
Lop Keung
LK
Chow
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000539:Alveolar Process / Q000033:anatomy & histology*; D002508:Cephalometry / Q000379:methods; D054893:Cone-Beam Computed Tomography; D015921:Dental Implants; D004955:Esthetics, Dental; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D007180:Incisor / Q000033:anatomy & histology*; D008297:Male; D008437:Maxilla / Q000033:anatomy & histology*; D008875:Middle Aged; D009811:Odontometry / Q000379:methods; D021362:Palate, Hard / Q000033:anatomy & histology; D019227:Tooth Apex / Q000033:anatomy & histology; D014092:Tooth Root / Q000033:anatomy & histology; D020390:Tooth Socket / Q000033:anatomy & histology; D016896:Treatment Outcome; D055815:Young Adult
D015921:Dental Implants