Henry Percy Pickerill was born in Hereford, England, on 3 August 1879, the son of Mary Ann Gurney and her husband, Thomas Pickerill, a commercial clerk, later the managing director of a tile factory. He attended Hereford County College, and the universities of Oxford and Birmingham. His first qualification in dentistry was the licentiate in dental surgery of the Royal College of Surgeons of England in 1903. From Birmingham he qualified BDS and MB, ChB in 1904, MD and MDS, both in 1911, and MCh in 1923. The distinctions and prizes he gained during his undergraduate years indicate the directions his career would take: awards in operative dentistry and anaesthesia, a prize for a treatise on the care of children's teeth, and a special prize for a paper on the effects of civilisation on teeth.
After completing his bachelor's degrees, Pickerill worked in a dental practice in Hereford and in the dental department of the General Hospital in Birmingham. He also held an appointment as lecturer in dental pathology and histology at the University of Birmingham. He married Mabel Louise Knott on 19 June 1906 at Birmingham; they were to have three sons and one daughter.
From 1907 entry to the dental profession in New Zealand was restricted to those who had completed a degree or certificate of proficiency in dental surgery from the University of New Zealand. A dental school was established by the University of Otago, and in September 1907 Pickerill became its first director. During a long and bitter fight over whether dentists should be university-trained or come through a system of apprenticeship, Pickerill led the argument for the high standards of training which he introduced. He had also to cope with a shortage of students, a problem not resolved until a system of bursaries for dental students was established in 1917.
During these difficult years Pickerill also did a great deal of research. A notable contribution was his book The prevention of dental caries and oral sepsis, for which he received the Cartwright Prize of the Royal College of Surgeons of England in 1911. Stomatology in general practice: a textbook of diseases of the teeth and mouth was published in 1912. His many papers included articles on the structure of dental enamel, the nature of saliva and its role in the prevention of tooth decay, theories of immunity to tooth decay, surgical reconstruction following trauma to the face and jaws, and the correction of congenital anomalies. He also prepared a series of articles on tooth decay in Maori people. He was editor of the New Zealand Dental Journal from 1909 to 1916.
In 1916 Pickerill took leave from the University of Otago to undertake wartime duties. Arriving in England in early 1917, he was seconded to the New Zealand Medical Corps and established a unit for the treatment of facial and jaw injuries at No 2 New Zealand General Hospital at Walton-on-Thames. The unit was transferred to the Queen's Hospital, Sidcup, in 1918. Pickerill established a reputation in the fields of facial reconstruction and plastic surgery, after achieving remarkable results in the treatment of horrific war wounds. The unit transferred to Dunedin in 1919, and he continued the long-term care of many wounded men as surgeon in charge of the facial and jaw department at Dunedin Hospital. Pickerill was made an OBE in 1919, and a CBE in 1923.
Resuming his position as dean of the Dental School in 1919, Pickerill found that the number of students had increased and dentistry as a university discipline was firmly established. New battles were soon to be fought. The old school was now too small, but before government approval was given for a new building a powerful lobby group from Auckland sought to have a dental school established there. Pickerill's forceful advocacy that the dental school be associated with the country's only medical school prevailed. Approval for the new building was given in April 1924, and it opened in June 1926. He was not so successful in another battle. Pickerill strongly opposed proposals to establish a child dental health programme to be staffed by school dental nurses who were to receive just 18 months' training. His efforts failed to prevent the establishment of the New Zealand School Dental Service in 1921.
Pickerill resigned from the University of Otago in 1927 to specialise in plastic surgery and took up a post at the Royal North Shore Hospital in Sydney as senior plastic surgeon. After divorcing Mabel Pickerill, he married Cecily Mary Wise Clarkson at Sydney on 17 December 1934; they were to have one daughter. Cecily was also a surgeon. They returned to New Zealand, and Pickerill worked for five years at Wellington Hospital and at Lewisham Hospital, Newtown. He and Cecily, to whom he had taught all his surgical techniques, established the first plastic surgery unit at Middlemore Hospital, Auckland, where they worked for three years.
In 1939 Henry and Cecily Pickerill established Bassam Hospital in Lower Hutt, where they specialised in the surgical correction of cleft lips and palates in children. Bassam was the first hospital in New Zealand to offer live-in accommodation for mothers and to involve them in the care of their children. This was an important development in the prevention of infection and in ensuring a strong bond between mother and baby.
Henry Pickerill died at Pinehaven, Upper Hutt, on 10 August 1956, ending a remarkable career. He had ensured that dental education in New Zealand was founded on high academic and clinical standards, and had made major contributions to several fields of dentistry and medicine both in New Zealand and overseas. The work at Bassam continued under the direction of Cecily Pickerill until 1967. She was made a DBE in 1977 and died in July 1988.