Free excerpt - SAC Classification in Implant Dentistry

3 RISKS IN IMPLANT DENTISTRY

Class I: No defect

Class II: Vertical defect

Class III: Horizontal defect

Class IV: Combined defect

Esthetic risk

Structural risk

Fig 16. The LTR classification. Visual representation of the four major indications related to the maxillary complete edentulous situation. Note that the classification is based on the defect present between the ridge and the lip horizontally and the prosthetic tooth and ridge vertically. The bone availability for implant placement does not influence the type of indication. (From Pollini et al, 2017, with permission).

The EERA consists of seven clinical risk factors that influence esthetic outcomes when managing fully edentulous arches with implant-assisted prostheses. Table 4 highlights these risk factors. Several factors have been addressed in publica- tions by Zitzmann and Marinello in 1999 and as mentioned previously Pollini and coworkers in 2017. An important key factor when utilizing the EERA is to consider all treatment

approaches and options (ie, fixed vs. removable and varia- tions). Doing so will ensure that the clinical and diagnostic findings assist in the identification of information-driven treatment choices. This approach often identifies the need for either an analog (wax try-in) and digital tooth arrange- ment to determine and review potential treatment out- comes and to effectively utilize the EERA (Figure 17).

Table 4 Edentulous esthetic risk assessment (EERA).

Esthetic risk factors - Edentulous

Level of risk

Low

Medium

High

Arch

Mandible

Maxilla

Facial support (fixed)

Alveolar process provides adequate facial support Flange provides adequate facial support

Minimal changes tolerated by the patient Minimal changes tolerated by the patient Minimal changes tolerated by the patient

Flange required for adequate facial support

Facial support (removable)

Insufficient space for a flange

Labial support

Designed tooth position provides satisfactory labial support

Designed tooth position causes unsatisfactory labial support

Upper lip length

Long upper lip (> 20 mm)

Short upper lip (< 20 mm)

Buccal corridor* (atrophic ridge)

Removable prosthesis

Fixed prosthesis

Smile line

No display of the ridge(s) at full smile (maxilla or mandible)

Display of the ridge(s) at full smile (maxilla or mandible)

Maxillomandibular relationship

Class I

Class II

Class III

*Desired narrow corridor in definitive prosthesis.

Fig 17 a–c. Example of a digital tooth arrangement for a full-mouth rehabilitation. a b

c

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The SAC Classification in Implant Dentistry