Introduction 17 23 30 22 31 3 36 37 5 5 15 11 12 36 Hopkins Symptoms Checklist 36 38 3 37 37 After reviewing the related literature, it is clear that the proportion of patients with sensory disturbances varies among publications. It is therefore essential to assess if neurosensory changes take place after the immediate loading of oral osseointegrated implants in the edentulous mandible in patients who received a fixed prosthetic construction on the day of implant insertion or the next day. 6 11 27 12 In some studies, questionnaires were used to evaluate the presence of sensory disturbances. Such methodology is clinically helpful and is a good basis for more detailed and objective evaluations. 8 The overall aim of the present research is to objectively evaluate the neurosensory disturbances and/or function occurring after placement of oral implants in the anterior region of the mandible. Materials and methods ® Brånemark Novum System ® Appendix 39 ® ® 10 ® ® How would you describe the altered feeling? Do you notice the altered feeling constantly or only when touching the area, or chewing, or talking? Is it painful? Where? Transient or constant? Does it start spontaneously or is it evoked by touching, chewing, or speaking? What exacerbates the pain? What relieves the pain? After thorough questioning about the patient’s general and oral medical history, an extra- and intraoral clinical examination took place, including palpation and/or percussion, to detect eventual provoked pain at the site of injury. Finally, inspection of the oral cavity was performed to find eventual evidence of nerve injury, self-induced trauma, etc. 1 2 3 Fig. 1 Two-point discrimination instrument  Fig. 2 Thermal sensitivity instrument  Fig. 3 ®  20 ® 21 ® Results n The mean time between the placement of the implants and the reception of the questionnaire was 20 months (range 8–40 months). n n The most commonly affected sites in the 19 patients were the gingiva only (6 patients), the inferior lip only (4 patients), and the chin (4 patients). One of the patients did not remember or could not determine the affected zone. Speaking and drinking (five patients) were the oral activities most commonly impaired by the altered sensations. An important part of the affected population group (12 patients) didn’t complain about problems with oral function or daily activity. The most common reported sensation was numbness (nine patients), followed by cutting, beating, and itching reported by two patients. Only one patient considered that the benefits of a fixed prosthesis did not outweigh the disadvantages that she had experienced as a result of disturbances in sensation of the lower jaw. She considered that she would not have done this surgery again, if she had been informed beforehand about the potential sensory changes in the orofacial region. From the 19 patients, 9 volunteered to participate in the objective evaluation (test group). The test group was 30–71 years old (mean age 56 years, seven women). N ® Results of the psychological and psychophysical tests As mentioned above, each of the 19 patients of the self-declared affected population was invited for a clinical evaluation and 9 of the 19 patients accepted to participate. The time span between surgery and psychophysical evaluation was on average 29 months (range 19–49 months). During the clinical interview, before the actual objective testing took place, none of the nine patients had remaining complaints or clinical symptoms such as drooling or tongue bite wounds that could indicate a sensory disturbance. However, at the reception of the questionnaire, which had to be mailed after the examination session, five of the nine patients with self-declared neurosensory disturbances still reported having them. In the remaining four patients the subjective neurosensory disturbances were completely resolved. ® ® N N 1 14 16 26 28 Table 1 Overview of psychophysical tests scores between test group, control group, and reference values Type test/Region Test group Control group Reference values Reference number T°S/LLLS 0.8 (CR) 0.9 (CR) 0.8 (CR) 18 T°S/LLRS 0.9 (CR) 0.9 (CR) 0.8 (CR) 18 T°S/LGLS 0.8 (CR) 0.8 (CR) 0.8 (CR) 18 T°S/LGRS 0.8 (CR) 0.8 (CR) 0.8 (CR) 18 2PD/LLLS 3.4 mm 4.5 mm 6.1±3.1 mm 19 3.3±1.6 mm 20 2±4 mm 21, 22 2PD/LLRS 3.4 mm 4.8 mm 6.1±3.1 mm 19 3.3±1.6 mm 20 2±4 mm 21,22 LTS/LGLS a a 4 (2.83) NF  19 LTS/LGRS a a 4 (2.83) NF 19 T°S LLLS LLRS LGRS LGLS CR 2PD mm LTS NF a p p Discussion 25 24 11 12 2 4 It is interesting to know that eight patients had the impression to be affected by some kind of persistent neurosensory disturbance, most probably paresthesia or hypoesthesia, more than 12 months after the surgery. Nevertheless, besides these results, a majority of these affected patients considered that the benefits outweigh this kind of transient or permanent disadvantages, and consider that they would accepted an implant surgery again even if they knew about the present complication. Normal somatic sensation reflects a continuous day and night monitoring process. Little of this activity reaches consciousness under ordinary conditions. Disordered sensation is alarming and dominates the sufferer’s attention. As expected from the neuroanatomical knowledge recently collected, neurosensory disturbances regularly occur in the anterior region of the mandible after surgery. Anatomical factors like the presence of an anterior loop, handling of the mental nerve during surgery, or the perforation of the incisive nerve canal can all provoke such disturbances. ® 35 29 9 7 14 37 19 32 33 1 13 ® 33 n There are no data in literature to compare neurosensory disturbances after immediate loading with those after the two-stage protocol. It is clear that it is difficult for the patient to distinguish between postoperative inconveniences, early functional adaptation, and real neurosensory dysfunction. Only a differential objective diagnosis can do so. 18 34 Conclusions The use of a questionnaire to determine the presence or absence of a problem after a medical procedure is easy and inexpensive; but to clarify the type, magnitude, extension, and eventual persistence of the neurosensory disturbance, the use of objective methods (i.e., psychophysical methods) in the evaluation of a population affected by any sensory disturbance, when complaints are detected, is highly recommended. The objective follow-up revealed that patients are often not impaired by, and even not aware of, neurosensory dysfunctions after implant surgery in the anterior mandible. Objective tests indicate however that tactile threshold levels may be elevated after such surgery. None of the patients suffering from this impaired tactile function seems to have functional deficits resulting from it. Based on these data, proper preoperative planning using cross-sectional imaging can be advised even for surgical procedures in the symphyseal region.