Significantly more complications occurred at both mandibular and maxillary grafted sites : @ augmented patients were affected by complications versus @ patients treated with short implants in the mandible ( P = @ ; difference in proportion = -@ ; @ % CI -@ to -@ ) , and @ sinus-lift patients versus none treated with maxillary short implants ( P = @ ; difference in proportion = -@ ; @ % CI -@ to -@ ) .