Dear Editor,

I read with interest a recent article titled “Is anterior guidance a key factor on planning implant treatment for free-end missing in the posterior mandible?”1  in the Journal of Oral Implantology (JOI); however, the title could confuse the readers regarding the meaning of “free-end missing.”

Neither “free-end missing” nor “free-end” can be found in the JOI Glossary of Terms (JOIGT), 2  which is an excellent publication of the JOI. It is a collection of words, phrases, and definitions specifically used in general dentistry, implantology, and oral surgery. Furthermore, neither are these terms included in the Glossary of Prosthodontic Terms (GPT)3  by the Academy of Prosthodontics, the oldest authoritative specialty organization in prosthetic dentistry.

“Free-end missing” could mean the absence of a free-end or the distal extension of a partial denture, as in case of denture breakage. The article, however, did not include the words “free-end missing”—except for in its title—but addressed “implant-supported fixed partial dentures” to restore “3 teeth missing in the left mandibular region (No. 35: second premolar, No. 36: first molar, and No. 37: second molar),” referred to as “unilateral posterior edentulous mandible.” I believe the authors intended to refer to these missing posterior teeth by the term “free-end missing” and not the free-end of the dentures.

Both the JOIGT and the GPT suggest the use of “Class II of the Kennedy's classification of partially edentulous arches,” which refers to unilateral edentulism distal to the remaining natural teeth. The concept of edentulism is not referred to as “free-end,” resulting in a logical flaw. The results of a thorough PubMed search revealed that the term “free-end missing” has been used only in papers by a few Japanese prosthodontists. Not only the English translation but also the concept underlying the original terminology should be reconsidered while using specific terms in academic as well as clinical use.

1. 
Nagao
M,
Masaki
C,
Nakao
M,
et al.
Is anterior guidance a key factor on planning implant treatment for free-end missing in the posterior mandible?
J Oral Implantol
.
2019
;
45
:
100
105
.
2. 
JOI Glossary of Terms
.
Chicago, Ill
:
American Academy of Implant Dentistry
;
2016
.
3. 
The Glossary of Prosthodontic Terms
.
9th ed.
San Deigo, Ca
:
Academy of Prosthodontics
;
2014
.
https://www.academyofprosthodontics.org/. Accessed November 11, 2019.