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rev port estomatol med dent cir maxilofac . 2019;60(4):175-188 179

sinus and the nasal cavity. In the posterior region, the first
molar position is considered. The height is measured from the
>6-mm width level of the alveolar ridge to the inferior wall of
the maxillary sinus.
In the mandible, the measurements are also made in five
positions: in the anterior region, at the midline and on each
side of the mandible at 4 mm anterior to the position of the
mental foramen. The height is measured from the >6-mm
width crestal level to the inferior border of the mandible. In
the posterior region, the first molar position is considered. The
posterior therapeutic bone height is measured as the distance
from the >6-mm width bone crest level to a 2-mm safe dis- Figure 5. Example of Maxilla CC Class I, Option A and
tance to the mandibular canal. Mandible CC Class IV, Option A
The therapeutic height and width values suggested for
each CC class are based on experience and the result of a con-
secutive preoperative CBCT analysis of 150 edentulous maxil- implants are placed in the first molar position. In case of op-
lae and 150 edentulous mandibles performed by the author posing natural dentition with a functional second molar, the
(Table 1). posterior implants should be placed in a way that enables
function, preferably without a cantilever. A fixed cross-arch
prosthesis without a distal cantilever is proposed (Figure 5).
Option B – Placement of four equidistant straight implants.
Table 1. Prevalence according to the proposed classes of
bone atrophy for both jaws. Retrospective analysis of The two anterior implants should be placed at the canine po-
150 consecutive cases of maxillary and 150 consecutive sition and the two posterior implants at the first molar posi-
of mandibular edentulous patients. tion. A fixed cross-arch prosthesis without a distal cantilever
is proposed.
Maxilla Mandible
Option C – Placement of a full-arch removable prosthesis. An
Class
Number Percentage Percentage Number overdenture supported by four non-splinted implants is
of cases of cases of cases of cases
placed in the anterior region of the maxilla in the lateral inci-
5 3.3% I 12.0% 18 sor and first premolar positions.
18 12.0% II 26.7% 40
deciding factor
35 23.4% III 34.0% 51 The main deciding factor for choosing Option A or B is the
arch size. Short edentulous arches and, therefore, a small
51 34.2% IV 18.7% 28
surgical space available between first molar positions sug-
41 27.1% V 8.7% 13 gest Option B. Based on the author’s clinical experience, this
150 100 Total 100 150 option is less prevalent. However, in cases weighting other
biomechanical factors such as the presence of natural teeth
in the opposing arch or parafunctional habits, Option A
should be selected.
Carames Classification (CC) classes description, therapeutic op- Option C (CCI, CCII and CCIII) is specifically indicated in
tions and deciding factors patients with any cognitive or physical impairment. An eden-
tulous older adult who needs daily assistance or has some
Maxilla CC I degree of dependence could be a candidate for this therapeu-
Anterior – Available bone (height >16 mm; width >6 mm) tic option, as it offers a favorable condition and maintenance
Posterior – Available bone (height >12 mm; width >6 mm) of oral hygiene. Medical or economic factors and reduced pa-
In the anterior region of the maxillae, the height measured tient compliance, which require minimally invasive surgical
from the >6-mm width crestal level to the inferior border of interventions and the lowest possible number of rehabilitation
the nasal cavity is >16 mm. In the posterior region, the height appointments, can also justify this option. 2
from the alveolar ridge to the inferior wall of the maxillary
sinus is at least 12 mm. Maxilla CCII
Anterior – available bone: height >16 mm; width >6 mm
therapeutic options Posterior – moderate resorption: height >8 mm and <12 mm;
The available bone in the anterior and posterior regions al- width >6 mm
lows for the placement of axial or straight implants. In the anterior region, the height measured from the osteoto-
my level, with a >6-mm crestal width, to the inferior border of
Option A – Placement of six straight equidistant implants. the nasal cavity is >16 mm. In the posterior region, moderate
The four anterior implants are placed between the anterior posterior bone resorption is found. The bone height measured
walls of the maxillary sinuses. Their entry points are the lat- from the alveolar ridge with a >6-mm crestal width to the
eral incisors and first premolars positions. The two posterior inferior wall of the maxillary sinus is >8 mm and <12 mm.